Injection mold cooling device

Abstract

The present application relates to the technical field of plastic forming, and discloses an injection mold cooling device, which comprises a mold frame and a mold body, the mold body is installed on the mold frame, a flow channel net group is arranged in the mold body, a first end of a preheating pipe is connected with a fluid for preheating, a second end of the preheating pipe is communicated with an inlet of the flow channel net group, so as to supply the fluid preheated into the flow channel net group, a heat exchange chamber is connected with a suction device for sucking the fluid for preheating of the flow channel net group into the heat exchange chamber, at least part of a cooling pipe extends through the heat exchange chamber, one end of the cooling pipe is used for connecting with a fluid for cooling, and the other end of the cooling pipe is communicated with the inlet of the flow channel net group. The injection mold cooling device preheats the mold body in advance by using the fluid for preheating, so that the temperature difference between the mold body and the plastic raw material is prevented from being too large, and the quality and appearance of the plastic product after forming are ensured.

Description

Technical Field

[0001] This invention relates to the field of plastic molding technology, and more specifically to a cooling device for injection molds. Background Technology

[0002] Injection molding is a common method for processing plastics. It involves injecting molten plastic material into a mold cavity using an injection device (such as a screw or plunger). After cooling and solidification, a plastic product of the desired shape is obtained. In injection molding, once the molten plastic material is injected into and fills the mold cavity, it can be cooled to solidify, thereby forming a product with a specific shape and structure.

[0003] Chinese patent document CN116968282B discloses an injection mold with high-efficiency cooling, which includes a cooling seat and a mold body. The cooling seat has an upward-facing cooling cavity, and the mold body can move vertically in and out of the cooling cavity. The cooling seat is equipped with a lifting device for controlling the vertical sliding of the mold body. A partition ring seat is fixed inside the cooling cavity, and a spiral curved tube for introducing cooling water is provided inside the partition ring seat. The mold body can be placed inside the spiral curved tube when descending.

[0004] Initially, the workers inject the mold body, then use a lifting device to guide it into the spiral tube. Cooling water flows upwards within the spiral tube, and the cool air emitted by the water gradually cools the mold body, creating a gradual cooling process—the first stage of cooling. Once the spiral tube is full of cooling water, it splits out from a branch pipe at the top. One stream flows outside the partition ring seat, continuously raising the water level and cooling the mold body through the partition ring seat—the second stage of cooling. The other stream flows through the water collecting ring and protective ring cover into the partition ring seat, allowing the mold body to directly contact the cooling water, achieving the third stage of cooling.

[0005] Although the above-mentioned injection mold achieves gradual cooling of the mold body and avoids air bubbles in the molding process due to rapid cooling of the plastic raw material, during continuous production, the cooled mold body is in a low-temperature state. When it comes into contact with the molten plastic raw material, the large temperature difference can easily lead to an accelerated cooling rate of the plastic, which slows down the flow rate of the plastic in the mold cavity and causes uneven flow, thus affecting the quality and appearance of the product. Summary of the Invention

[0006] This invention provides a cooling device for injection molds, which aims to solve the problem of product quality being affected when the cooled mold body is directly molded into plastic in related technologies.

[0007] This invention discloses a cooling device for an injection mold, comprising a mold frame and a mold body, the mold body being mounted on the mold frame. The mold body has an internal flow channel network, within which a preheating fluid or a cooling fluid flows. It also includes a preheating pipe and a cooling pipe. A first end of the preheating pipe is connected to the preheating fluid, and a second end is connected to the inlet of the flow channel network to supply preheated fluid into the flow channel network. The outlet of the flow channel network is connected to a heat exchange chamber, which is equipped with a suction device for drawing the preheating fluid from the flow channel network into it. At least a portion of the cooling pipe extends through the heat exchange chamber, with one end for receiving cooling fluid and the other end connected to the inlet of the flow channel network. As the cooling fluid flows through the cooling pipe and into the flow channel network, it gradually carries away heat from the preheating fluid in the heat exchange chamber.

[0008] The advantages are as follows: This invention, through the use of preheating and cooling pipes, achieves preheating of the mold body, preventing it from cooling to a low temperature. In other words, preheating prevents excessive temperature difference between the mold body and the molten plastic material, thus avoiding rapid cooling of the plastic material upon contact with the mold body. This ensures stable and uniform flow of the plastic material in the cavity, thereby guaranteeing reliable quality and a smooth appearance of the molded product. Furthermore, the preheating fluid and cooling fluid exchange heat in the heat exchange chamber. When the cooling fluid cools the mold body, the mold body temperature is not rapidly and locally scalded due to the low temperature of the cooling fluid, preventing uneven quality of the injection molded product. Rapidly cooled products may have a solidified exterior while the interior remains molten, leading to significant deformation. By raising the temperature of the cooling fluid during the initial cooling process, the cooling of the injection molded product is gradual, ensuring its precision. At the same time, the cooling process of the cooling fluid on the mold body is gradual, avoiding rapid cooling of the mold body and causing structural damage. It also makes full use of the heat in the preheating fluid and avoids waste.

[0009] Preferably, the suction device includes a piston body and a driving device. The piston body is vertically slidably sealed in a cylindrical heat exchange chamber and is vertically arranged in the extension direction of the cooling pipe that exchanges heat with the preheating fluid. The driving device is mounted on the mold frame and is used to drive the piston body to slide, draw the preheating fluid into the heat exchange chamber, and control the volume of the heat exchange chamber by the sliding distance of the piston body.

[0010] Its effect is that the drive device controls the sliding of the piston body, so that the preheating fluid in the flow channel network can enter the heat exchange chamber, thereby facilitating heat exchange with the cooling fluid in the cooling pipe, appropriately increasing the temperature of the cooling fluid, and controlling the volume of the heat exchange chamber by moving the piston body up and down, thereby controlling the cooling curve of the injection molded product.

[0011] Preferably, the portion of the cooling pipe located within the heat exchange chamber is coiled and surrounded by a heat exchange sleeve; the piston body has an inner hole, and the piston body is sealed to the outer wall of the heat exchange sleeve through the inner hole, with thermally conductive material filling the space between the inner wall of the heat exchange sleeve and the outer wall of the cooling pipe.

[0012] Its effect is that the coiled structure of the cooling pipe increases the heat exchange efficiency with the preheating fluid in the heat exchange chamber.

[0013] Preferably, the injection assembly includes a barrel, a screw, and a heating element. The barrel is mounted on the mold frame and its outlet end communicates with the cavity. The screw is rotatably mounted inside the barrel so as to deliver molten plastic raw material toward the outlet end of the barrel during rotation. The heating element is disposed on the outer wall of the barrel and is used to heat the plastic raw material. A jacketed cavity is formed inside the barrel shell, and the preheating pipe is embedded in the jacketed cavity and has a coiled structure.

[0014] Preferably, a first separation mechanism for severing the connection between the second end of the preheating pipe and the inlet of the flow channel mesh assembly is provided. The first separation mechanism includes a sliding member and a sealing member. The sliding member is slidably assembled on the mold body, and the mold body is provided with a driver for driving the sliding member to slide. A frame is formed at the connection between the second end of the preheating pipe and the inlet of the flow channel mesh assembly. The frame has an opening facing the sliding member. The sealing member is slidably fitted in the frame, and one end extends out of the opening of the sliding member and is connected to the sliding member, so that the sliding member drives the sealing member to seal the frame when it slides.

[0015] Its effect is that, although the preheating fluid and the cooling fluid use the same medium, the preheating fluid and the cooling fluid only need to exchange heat in the flow channel network in the mold body, while the preheating fluid in the preheating pipe needs to be separated from the cooling fluid. Therefore, the sealing of the frame by the sealing component prevents the cooling fluid in the flow channel network from flowing into the preheating pipe and mixing with the preheating fluid.

[0016] Preferably, the second end of the preheating pipe is elastically slidably connected to a pipe head, and the frame includes a first U-shaped frame fixed to the outer wall of the mold body and a second U-shaped frame fixed to the pipe head. The second U-shaped frame and the first U-shaped frame can abut against each other under the elastic compression of the pipe head.

[0017] The sealing component includes a first sealing component that fits into the first U-shaped frame and a second sealing component that fits into the second U-shaped frame. The first sealing component is connected to the sliding component via an elastic telescopic component. The second sealing component is hinged to the sliding component. After the first sealing component and the second sealing component respectively seal the first U-shaped frame and the second U-shaped frame, the connecting component is used to deflect as the sliding component slides, thereby separating the second U-shaped frame from the first U-shaped frame.

[0018] Its effect is that the separation of the second U-shaped frame from the first U-shaped frame prevents strong heat exchange between the cooling fluid in the flow channel network and the preheating fluid in the preheating pipe, ensuring their independence and avoiding interference and influence.

[0019] Preferably, the sealing element is made of heat-insulating material, and the sealing element enters the frame to separate the preheating pipe from the fluid in the flow channel network.

[0020] Preferably, a second separation mechanism is provided between the outlet end of the cylindrical shell and the cavity to isolate the two from each other.

[0021] Its effect is that the second separation mechanism separates the outlet end of the cylinder shell from the cavity, so as to prevent the product in the cavity from cooling down the plastic raw material in the cylinder shell, thereby ensuring the continuity of the next injection molding process.

[0022] Preferably, the mold body includes a die and a punch. The die is mounted on the mold frame and its interior is used to form the cavity. The punch has a core that matches the cavity. The mold frame is provided with a mold closing system connected to the punch. The mold closing system is used to control the closing and separation of the punch and the die.

[0023] Preferably, the flow channel network assembly includes a first flow channel network disposed in the cavity and a second flow channel network disposed in the punch. The first flow channel network is arranged in a U-shape and has an open structure at both the top and bottom. The two ports at the top of the first flow channel network are respectively connected to the second flow channel network through two guide telescopic tubes. One of the two guide telescopic tubes is used to guide the fluid of the first flow channel network into the second flow channel network, and the other is used to guide the fluid of the second flow channel network into the first flow channel network. The two ports at the bottom of the first flow channel network respectively form the inlet and the outlet.

[0024] By adopting the above technical solution, the beneficial effects of the present invention are as follows:

[0025] This invention, through the use of preheating and cooling pipes, achieves two main benefits. First, it preheats the mold body, preventing it from being at a low temperature due to initial cooling. In other words, preheating prevents excessive temperature differences between the mold body and the molten plastic material, thus avoiding rapid cooling of the plastic material upon contact with the mold body. This ensures a stable and uniform flow rate of the plastic material within the mold cavity, thereby guaranteeing the quality and appearance of the molded product. This implementation also avoids prolonged placement of the mold body for reheating, shortening the mold body's reheating time and improving overall production efficiency. Second, the hot fluid and cooling fluid exchange heat in the heat exchange chamber, ensuring a gradual cooling process for the injection-molded product and guaranteeing its precision. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the external shape of the injection mold cooling device of the present invention.

[0027] Figure 2 This is a cross-sectional schematic diagram of the injection mold cooling device of the present invention.

[0028] Figure 3 This is a structural schematic diagram of the injection assembly, mold body, and mounting chamber of the present invention.

[0029] Figure 4 This is the invention Figure 3 Enlarged diagram of point A in the middle.

[0030] Figure 5 This is the invention Figure 2 Enlarged diagram of point B in the middle.

[0031] Figure 6 This is a schematic diagram of the guiding telescopic tube of the present invention.

[0032] Figure 7 This is a cross-sectional schematic diagram of the portion from the concave mold to the heat exchange chamber of the present invention.

[0033] Figure label:

[0034] 1. Mold frame; 11. Installation chamber; 12. Cylindrical structure; 121. Heat exchange chamber; 122. Pipe; 123. Piston body; 1231. Check valve; 124. Drive unit; 125. Cooling pipe; 126. Heat exchange jacket; 13. Cooling pump;

[0035] 2. Mold body; 21. Cavity; 211. Gating gate; 22. Punch; 221. Core;

[0036] 3. Injection assembly; 31. Shell; 311. Cylinder body; 312. Sleeve; 32. Screw; 33. Heating element; 34. Hopper; 35. Preheating tube; 351. Tube head;

[0037] 4. Flow channel network; 41. First flow channel network; 411. Inlet; 4111. Branch channel; 412. Outlet; 42. Second flow channel network; 43. Guide telescopic tube; 431. Main tube; 432. Daughter tube; 4321. Flange;

[0038] 5. First separation mechanism; 51. Sliding component; 52. Sealing component; 521. First blocking component; 5211. Spring telescopic rod; 522. Second blocking component; 5221. Connecting plate; 53. Driver; 54. Frame; 541. First U-shaped frame; 542. Second U-shaped frame;

[0039] 6. Second separation mechanism. Detailed Implementation

[0040] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0041] The following is combined Figures 1 to 7 The present invention describes a cooling device for injection molds.

[0042] like Figure 1 and Figure 2 As shown, the injection mold cooling device of the present invention includes a mold frame 1, a mold body 2, and an injection assembly 3.

[0043] Continue to refer to Figure 1 and Figure 2 The mold body 2 includes a cavity 21 and a punch 22. The cavity 21 is fixedly mounted on the mold frame 1 and has a cavity 211 inside for molding the outer surface of the plastic product. The punch 22 is movable relative to the cavity 21 and has a core 221 that matches the cavity 211. The core 221 is used to mold the inner surface of the plastic product. A mold closing system is installed on the mold frame 1. The mold closing system is connected to the punch 22 and is used to control the closing and separation of the punch 22 and the cavity 21. When closing, the core 221 fits in the cavity 211 and together with the cavity 211 molds the plastic product.

[0044] Continue to refer to Figure 2 and Figure 7The mold body 2 is equipped with a flow channel network 4 that can transfer heat with the mold body 2. The flow channel network 4 includes a first flow channel network 41 and a second flow channel network 42. The first flow channel network 41 is located in the cavity 21 and is arranged in a U-shape. The first flow channel network 41 surrounds the periphery of the cavity 211. The top and bottom of the first flow channel network 41 are open structures, so that the first flow channel network 41 has two opposing C-shaped structures. The second flow channel network 42 is located in the punch 22 and has a similar structure to the first flow channel network 41. The second flow channel network 42 is also arranged in a U-shape. The second flow channel network 42 surrounds the periphery of the core 221 and is also open at the top.

[0045] Continue to refer to Figure 2 , Figure 3 and Figure 6 The two ports at the top of the first flow channel network 41 are respectively connected to the two ports at the top of the second flow channel network 42 through two guide telescopic tubes 43. Specifically, the guide telescopic tube 43 can be an insert tube, one end of which is fixedly connected to one of the die 21 and the punch 22, and the other end is slidably inserted into the top port of the other. In this way, when the punch 22 and the die 21 are closed, the insert tube can be completely slid into the port, avoiding interference with the closing of the punch 22 and the die 21. Alternatively, the guide telescopic tube 43 may also include a mother tube 431 and a daughter tube 432. The mother tube 431 is fixedly connected to the punch 22. One end of the daughter tube 432 slides through the mother tube 431 and will not detach. The other end of the daughter tube 432 is placed in the port at the top of the die 21 and has a flange 4321 on its outer periphery. The edge of the flange 4321 rubs against and seals the wall of the port. Thus, when the punch 22 and the die 21 close, the daughter tube 432 will be subject to sliding resistance due to the frictional contact of the flange 4321 and will not slide easily. The mother tube 431 slides relative to the daughter tube 432, reducing the distance between them. When the mother tube 431 contacts the flange 4321, it pushes the flange 4321 to slide together, so that both the mother tube 431 and the daughter tube 432 slide into the port, avoiding interference with the closing of the punch 22 and the die 21.

[0046] refer to Figure 2 and Figure 6 It is worth noting that one of the guide telescopic tubes 43 is used to guide the fluid in the first flow channel network 41 into the second flow channel network 42, and the other guide telescopic tube 43 is used to guide the fluid in the second flow channel network 42 back into the first flow channel network 41. In this way, the fluid can flow through the first flow channel network 41 and the second flow channel network 42. Regardless of whether the punch 22 and the die 21 are in the closed state or the separated state, the fluid can transfer heat with the punch 22 and the die 21.

[0047] The two ports at the bottom of the first flow channel network 41 form an inlet 411 and an outlet 412, respectively. The inlet 411 is divided into two branch channels 4111.

[0048] Continue to refer to Figure 1 and Figure 2 The injection assembly 3 is located beside the mold body 2. The injection assembly 3 includes a barrel shell 31, a screw 32, and a heating element 33. The barrel shell 31 includes an inner barrel 311 and an outer sleeve 312. The barrel 311 and the sleeve 312 are fixedly connected. The sleeve 312 is fixed on the mold frame 1, and the mold frame 1 provides support for the sleeve 312. The center of the cavity 21 has a gate 212 that communicates with the cavity 211. The outlet end of the inner barrel 311 communicates with the gate 212. The inlet end of the barrel 311 protrudes out of the outer side of the sleeve 312 and is fixedly provided with a hopper 34 with the sprue facing upward. The hopper 34 is used to introduce granular plastic raw material into the barrel 311. The screw 32 is rotatably mounted inside the cylinder 311. A drive motor for driving the screw 32 to rotate is mounted on the cylinder 311. During rotation, the screw 32 delivers plastic raw material towards the outlet end of the cylinder 311, allowing the plastic raw material to flow through the gate 212 into the mold cavity 211 and be molded into a product. A heating element 33 is located on the outer wall of the sleeve 312. The heating element 33 can be a heating tube, an electric heating rod, a cast aluminum heater, or a ceramic heater. Its number is not limited to one; multiple elements can be arranged along the axial direction of the sleeve 312. The heating element 33 can heat the plastic raw material inside the cylinder 31 through the shell 31, causing it to change from a granular state to a molten state, and then maintain it in a molten state.

[0049] It should be noted that the sleeve 312 has a coaxial annular interlayer cavity inside its wall, and a preheating pipe 35 is embedded in the interlayer cavity. The preheating pipe 35 spirally surrounds the sleeve 311 and has a coiled structure. Both ends of the preheating pipe 35 penetrate the wall of the sleeve 312 and extend to the outside of the sleeve 312. Specifically, the first end of the preheating pipe 35 is away from the mold body 2 and is connected to a preheating pump. The preheating pump is used to introduce fluid at room temperature or obtained through heat recovery into the preheating pipe 35. The second end of the preheating pipe 35 is adjacent to the mold body 2 and is connected to a branch channel 4111 of the inlet 411. In this way, external fluid can flow into the first flow channel network 41 through the preheating pipe 35 and the inlet 411, and then into the second flow channel network 42 through the guide telescopic pipe 43. When flowing through the preheating pipe 35, the heating element 33 can preheat the fluid in the preheating pipe 35 through the sleeve 312, thereby increasing its temperature. Thus, when the preheated fluid flows in the first flow channel network 41 and the second flow channel network 42, it can preheat the die 21 and the punch 22 through heat transfer, thereby restoring their temperature.

[0050] Continue to refer to Figure 2 , Figure 5 and Figure 7The mold frame 1 has an installation chamber 11 located below the mold body 2. The installation chamber 11 has a vertical cylindrical structure 12. The top of the cylindrical structure 12 is closed, and the bottom is open and connected to the external environment of the installation chamber 11. The internal space of the cylindrical structure 12 forms a heat exchange chamber 121. The top wall of the cylindrical structure 12 is connected to the die 21 through a conduit 122. The conduit 122 connects the outlet 412 of the first flow channel network 41 to the heat exchange chamber 121 so that the preheating fluid in the first flow channel network 41 can be introduced into the heat exchange chamber 121 after preheating.

[0051] The heat exchange chamber 121 is equipped with a suction device for drawing the preheating fluid of the flow channel network 4 into it. The suction device includes a piston body 123 and a drive device 124. The piston body 123 is vertically slidably fitted in the heat exchange chamber 121. The drive device 124 is installed on the outer wall of the installation chamber 11 and its output end extends into the heat exchange chamber 121. The output end of the drive device 124 is connected to the piston body 123 to drive the piston body 123 to slide. In the initial state, the piston body 123 is located at the upper part of the heat exchange chamber 121. When the drive device 124 drives the piston body 123 to move downward, under the action of negative pressure, the piston body 123 can draw the preheating fluid in the first flow channel network 41 into the heat exchange chamber 121. Similarly, the preheating fluid in the second flow channel network 42 can also be drawn into the heat exchange chamber 121 along the guide telescopic tube 43 and the first flow channel network 41, realizing the storage in the heat exchange chamber 121. In this embodiment, the drive device 124 may be an electric push rod, a telescopic motor, a hydraulic rod, a pneumatic telescopic rod, etc.

[0052] The heat exchange chamber 121 is equipped with a cooling pipe 125 that extends vertically as a whole. The bottom end of the cooling pipe 125 extends to the bottom of the mounting chamber 11 and is connected to a cooling pump 13. The cooling pump 13 is used to introduce cooling fluid into the cooling pipe 125. The cooling fluid refers to preheated oil with a temperature below 40°C, such as room temperature. The top end of the cooling pipe 125 extends to the top of the mounting chamber 11 and is connected to another branch channel 4111 of the inlet 411.

[0053] It should be noted that the portion of the cooling pipe 125 located within the heat exchange chamber 121 is coiled, which increases the heat exchange efficiency between the cooling fluid within the cooling pipe 125 and the preheating fluid within the heat exchange chamber 121. A heat exchange jacket 126 surrounds the cooling pipe 125. The top end of the heat exchange jacket 126 is flush with the top end of the cylindrical structure 12 and the two are fixedly connected. The bottom end of the heat exchange jacket 126 is flush with the bottom end of the cylindrical structure 12 and is closed. Notably, the piston body 123 has an inner bore with a diameter equal to the outer diameter of the heat exchange jacket 126. The piston body 123 is sealed to the outer wall of the heat exchange jacket 126 through this inner bore. To adjust the heat transfer rate between the inner wall of the heat exchange jacket 126 and the cooling pipe 125, thermally conductive materials with different thermal conductivity coefficients, such as thermal oil, hot water, or thermal grease, can be filled between the inner wall of the heat exchange jacket 126 and the outer wall of the cooling pipe 125.

[0054] During injection molding, the mold clamping system controls the punch 22 and the die 21 to close, and the core 221 mates with the cavity 211. Particulate plastic material is fed into the cylinder 311 through the hopper 34. The drive motor drives the screw 32 to rotate, which transports the particulate plastic material to the outlet end of the cylinder 311. The material is gradually molten by the heating element 33, allowing it to flow through the gate 212 into the cavity 211 and be molded.

[0055] During this process, the preheating pump pumps the external preheating fluid into the preheating pipe 35. The heating element 33 preheats the preheating fluid in the preheating pipe 35 through the sleeve 312 and the cylinder 311, raising its temperature to become a preheated fluid. The preheating fluid is preheating oil. The preheating fluid flows into the first flow channel network 41, the guide telescopic pipe 43 and the second flow channel network 42. Through heat transfer, the concave mold 21 and the convex mold 22 are preheated to prevent their temperature from being too low due to the previous cooling. In other words, the preheating prevents the temperature difference between the mold body 2 and the molten plastic material from being too large, thereby preventing the plastic material from cooling rapidly when it comes into contact with the mold body 2. This ensures that the flow rate of the plastic material in the cavity 211 is stable and the flow is uniform, thus ensuring the reliable quality and smooth appearance of the product after the plastic material is molded.

[0056] During cooling, the drive device 124 drives the piston 123 to move downwards, and the piston 123 draws the preheating fluid in the flow channel network 4 into the heat exchange chamber 121. The cooling pump 13 pumps external cooling fluid into the cooling pipe 125. When the cooling fluid flows through the heat exchange chamber 121, it can exchange heat with the preheating fluid through the cooling pipe 125, the thermally conductive material, and the heat exchange jacket 126, realizing the reuse of the heat of the preheating fluid and avoiding waste, while also achieving an appropriate increase in its own temperature. The appropriately heated cooling fluid flows into the first flow channel network 41, and then flows into the second flow channel network 42 through the guide telescopic pipe 43, thus flowing throughout the flow channel network 4. The cooling fluid can cool the mold body 2. Since the cooling fluid has been appropriately heated, the cooling process of the mold body 2 is not aggressive, but proceeds gradually. As the cooling fluid continuously flows into the flow channel assembly 4, the heat utilized by the preheating fluid is gradually depleted, and the temperature of the cooling fluid decreases. This ensures that the cooling process of the mold body 2 is gradual, preventing rapid cooling of the mold body 2 and thus avoiding deformation of the injection molded product. After the mold body 2 has cooled down, the mold closing system can control the separation of the punch 22 and the die 21, removing the molded plastic product. The cooling process accelerates the molding and curing process of the plastic product.

[0057] The above operation can be repeated when the mold body 2 is continuously producing molded plastic products.

[0058] It is worth noting that the piston body 123 is provided with an outlet, and a one-way valve 1231 is provided in the outlet. The one-way valve 1231 is used to allow the preheating fluid in the heat exchange chamber 121 to flow out of the heat exchange chamber 121 in one direction. When the heat of the preheating fluid in the heat exchange chamber 121 is exhausted, the drive device 124 can drive the piston body 123 to move upward to reset it. Since the flow channel mesh 4 is filled with cooling fluid at this time, the preheating fluid in the heat exchange chamber 121 cannot flow back into the flow channel mesh 4 due to the obstruction of the cooling fluid. It can only flow out through the one-way valve 1231 to achieve the purpose of external discharge. The one-way valve 1231 is model DIF-L10H1, and the opening pressure is 0.04MPa. When the piston body 123 is not squeezing the preheating fluid in the heat exchange chamber 121, the one-way valve 1231 has not reached the opening pressure.

[0059] Special attention should be paid to the fact that when the preheating fluid enters the runner assembly 4, the existing cooling fluid in the runner assembly 4 needs to move downwards through the piston body 123 simultaneously. This allows the cooling fluid, which has already been heated in the punch 22 and die 21, to be drawn out of the runner assembly 4 and into the heat exchange chamber 121. This ensures that the preheating fluid in the runner assembly 4 completely replaces the cooling fluid. At this time, the piston body 123 still retains space to move downwards. After injection molding is completed, when cooling fluid needs to be introduced into the runner assembly 4, the piston body 123 continues to move downwards. At this time, the existing preheating fluid in the runner assembly 4 can be drawn into the heat exchange chamber 121 to heat up the cooling fluid, so that... The temperature of the cooling fluid gradually decreases. When the duration of the slow cooling process of the cooling fluid for some injection molded products is short, the piston body 123 can be moved up or down after entering the cooling fluid through the cooling pipe 125, thus reducing the volume of the heat exchange chamber 121 and reducing the heat exchange process between the preheating fluid and the cooling fluid. At this time, the cooling fluid can be discharged through the flow channel network 4, the reduced heat exchange chamber 121, and the one-way valve 1231. Therefore, the cooling curve of the injection molded product can be controlled by the position and movement of the piston body 123, ensuring that the injection molded product is in the best curing state and improving the quality of the injection molded product.

[0060] Continue to refer to Figures 2 to 4 When the cooling fluid flows in the flow channel network 4, in order to prevent the cooling fluid from flowing into the preheating pipe 35 and to prevent the cooling fluid from affecting the preheating fluid in the preheating pipe 35, a first separation mechanism 5 is provided between the second end of the preheating pipe 35 and the branch channel 4111 of the inlet 411 of the flow channel network 4 to isolate the connection between the two.

[0061] Specifically, the first separation mechanism 5 includes a sliding member 51 and a blocking member 52. The sliding member 51 is vertically slidably mounted on the outer wall of the die 21. The die 21 is provided with a driver 53 for driving the sliding member 51 to slide. The driver 53 can be a lead screw slider mechanism, an electric telescopic rod, a hydraulic cylinder, etc.

[0062] A frame 54 is formed at the connection between the second end of the preheating pipe 35 and the branch channel 4111 of the inlet 411 of the first flow channel mesh 41. The frame 54 is located below the sliding member 51 and its opening faces the sliding member 51. The frame 54 includes a first U-shaped frame 541 and a second U-shaped frame 542. The first U-shaped frame 541 is fixed to the outer wall of the cavity mold 21. The second end of the preheating pipe 35 is slidably fitted with a pipe head 351. The pipe head 351 is connected to the preheating pipe 35 by a compression spring (not shown in the figure). The second U-shaped frame 542 is fixed on the pipe head 351. Under the action of the compression spring, the second U-shaped frame 542 and the first U-shaped frame 541 can abut against each other. In order to ensure the sealing between the first U-shaped frame 541 and the second U-shaped frame 542, a sealing gasket can be fixedly provided on the surfaces where the first U-shaped frame 541 and the second U-shaped frame 542 abut against each other.

[0063] The sealing component 52 includes a first sealing component 521 vertically slidably fitted within a first U-shaped frame 541 and a second sealing component 522 vertically slidably fitted within a second U-shaped frame 542. The top end of the first sealing component 521 extends out from an opening and is connected to the sliding component 51 via an elastic telescopic component, which can be a spring telescopic rod 5211. The top end of the second sealing component 522 extends out from an opening and is hinged to the sliding component 51 by a connecting component. In this embodiment, the connecting component can be a connecting plate 5221. In other embodiments, the connecting component can also be a connecting rod, a connecting frame, etc.

[0064] When the driver 53 drives the sliding member 51 to move down, the sliding member 51 drives the first block 521 and the second block 522 to move down through the spring telescopic rod 5211 and the connecting plate 5221 until the first block 521 and the second block 522 move down to their limit positions and block the first U-shaped frame 541 and the second U-shaped frame 542. As a result, the first U-shaped frame 541 and the second U-shaped frame 542 are no longer connected. That is to say, the branch channel 4111 of the inlet 411 is closed and the second end of the preheating pipe 35 is closed. This prevents the cooling fluid in the flow channel network group 4 from flowing into the preheating pipe 35 and mixing with the preheating fluid. As the sliding member 51 continues to move downward, the first block 521 and the second block 522 will not continue to move downward. At this time, the spring telescopic rod 5211 is compressed, and the connecting plate 5221 will deflect to push the second block 522 horizontally. This causes the second block 522 to slide the second U-shaped frame 542 away from the first U-shaped frame 541. The second U-shaped frame 542 presses the tube head 351 towards the preheating tube 35, and the compression spring is further compressed. This achieves the separation of the second U-shaped frame 542 and the first U-shaped frame 541, preventing strong heat exchange between the cooling fluid in the flow channel network group 4 and the preheating fluid in the preheating tube 35, ensuring their independence and avoiding interference and influence.

[0065] When the driver 53 drives the sliding member 51 to move upward, the spring telescopic rod 5211 gradually returns to its original length, the connecting plate 5221 deflects in the opposite direction to its original position, and the tube head 351, under the action of the compression spring, makes the second U-shaped frame 542 and the first U-shaped frame 541 abut again.

[0066] Continue to refer to Figures 2 to 4 A second separation mechanism 6 is provided between the outlet end of the cylinder 311 and the gate 212 to isolate the two. The second separation mechanism 6 has the same structure as the first separation mechanism 5. The second separation mechanism 6 is also used to separate the outlet end of the cylinder 311 from the gate 212, making them independent of each other. This avoids the mold body 2 from affecting the molten plastic material in the cylinder 311 when it is cooling down, and also blocks the feeding of the plastic material in the cylinder 311 into the cavity 211.

[0067] In other embodiments, the sealing element 52 may be made of a heat-insulating material. The sealing element 52 is an integral unit. The heat insulation effect of the sealing element 52 is used to reduce the heat exchange between the preheating fluid and the cooling fluid at the second end of the preheating pipe 35, and to reduce the impact of the mold body 2 on the molten plastic material in the cylinder 311 when it is cooled down.

[0068] In other embodiments, the preheating tube 35 is separately equipped with other heating tubes, electric heating rods, cast aluminum heaters or ceramic heaters to heat the preheating fluid in the preheating tube 35. In this way, the preheating fluid in the preheating tube 35 can be water, and the cooling fluid in the cooling tube 125 can also be water.

[0069] In other embodiments, the cooling pipe 125 is arranged in a spiral shape inside the wall of the cylindrical structure 12 or the heat exchange jacket 126, and transfers heat to the preheating fluid through the wall of the cylindrical structure 12 or the heat exchange jacket 126.

[0070] In other embodiments, the cooling pipe 125 may be a vertical pipe, so that the piston body 123 is sealed to the outer wall of the cooling pipe 125 through the inner hole.

[0071] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. An injection mold cooling device comprising a mold frame, a mold body mounted on the mold frame, and a runner network group provided in the mold body, characterized in that, The preheating pipe and the cooling pipe are further included; The first end of the preheating pipe is connected with a fluid for preheating, and the second end is communicated with the inlet of the flow channel net group to supply the fluid for preheating into the flow channel net group; The outlet of the flow channel net group is connected with a heat exchange chamber, the heat exchange chamber is connected with a pumping device for pumping the fluid for preheating into the heat exchange chamber, at least part of the cooling pipe extends through the heat exchange chamber, one end of the cooling pipe is connected with a fluid for cooling, and the other end is communicated with the inlet of the flow channel net group; the fluid for cooling in the cooling pipe gradually takes away the heat of the fluid for preheating in the heat exchange chamber during flowing through the cooling pipe and flowing to the flow channel net group; The pumping device includes a piston body and a driving device, the piston body is vertically and sealingly slid in the cylindrical heat exchange chamber, and the part of the cooling pipe for heat exchange with the fluid for preheating extends vertically; the driving device is arranged on the mold frame to drive the piston body to slide and pump the fluid for preheating into the heat exchange chamber, and the volume of the heat exchange chamber is controlled by the sliding distance of the piston body; The part of the cooling pipe arranged in the heat exchange chamber is in the form of a coil pipe and is wrapped with a heat exchange sleeve on the side; the piston body is provided with an inner hole, and the heat exchange sleeve is sealingly sleeved on the outer wall of the heat exchange sleeve through the inner hole; the inner wall of the heat exchange sleeve and the outer wall of the cooling pipe are filled with a heat-conducting material; The mold body is connected with an injection assembly, the injection assembly includes a barrel, a screw and a heating element, the barrel is arranged on the mold frame and the outlet end is communicated with a cavity in the mold body, the screw is rotationally arranged in the barrel to transport molten plastic raw materials to the outlet end of the barrel during rotation, the heating element is arranged on the outer wall of the barrel to heat the plastic raw materials, and a sandwich cavity is arranged in the barrel, and the preheating pipe is arranged in the sandwich cavity and has a coil pipe structure; A first separation mechanism for separating the preheating pipe and the flow channel net group is arranged between the preheating pipe and the flow channel net group; The first separation mechanism includes a sliding piece and a blocking piece, the sliding piece is slidingly arranged on the mold body, and a driver for driving the sliding piece to slide is arranged on the mold body; the communication part of the preheating pipe and the flow channel net group forms a frame body, the frame body has an opening facing the sliding piece, and the blocking piece is slidingly arranged in the frame body and connected with the sliding piece at one end to drive the blocking piece to block the frame body when the sliding piece slides.

2. The injection mold cooling apparatus of claim 1, wherein The second end of the preheating pipe is elastically connected with a pipe head, the frame body includes a first U-shaped frame fixed on the outer wall of the mold body and a second U-shaped frame fixed on the pipe head; the blocking piece includes a first blocking piece fitted in the first U-shaped frame and a second blocking piece fitted in the second U-shaped frame, the first blocking piece is connected with the sliding piece through an elastic expansion piece, and a connecting piece is hinged between the second blocking piece and the sliding piece; after the first blocking piece and the second blocking piece block the first U-shaped frame and the second U-shaped frame respectively, the connecting piece is used for deflecting to separate the second U-shaped frame from the first U-shaped frame when the sliding piece slides.

3. The injection mold cooling apparatus of claim 1, wherein The blocking piece is made of heat insulation material, and the blocking piece separates the fluids in the preheating pipe and the flow channel net group when entering the frame body.

4. The injection mold cooling device of any of claims 1-3, wherein, A second separation mechanism for separating the outlet end of the barrel and the cavity is arranged between the outlet end of the barrel and the cavity.

5. The injection mold cooling apparatus of claim 1, wherein The mold body comprises a female die and a male die, the female die is mounted on the mold base and internally used for constituting a cavity inside the mold body, the male die has a core matched with the cavity, the mold base is provided with a die closing system connected with the male die, and the die closing system is used for controlling closing and separation of the male die and the female die.

6. The injection mold cooling apparatus of claim 5, wherein The flow channel net group comprises a first flow channel net arranged in the female die and a second flow channel net arranged in the male die, the first flow channel net is arranged in a mouth-shaped form and has open top and bottom structures, two ports of the top of the first flow channel net are respectively communicated with the second flow channel net through two guide telescopic pipes, one of the two guide telescopic pipes is used for guiding fluid of the first flow channel net into the second flow channel net, and the other is used for guiding fluid of the second flow channel net into the first flow channel net, and two ports of the bottom of the first flow channel net respectively form the inlet and the outlet.

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