Cooling device and method in injection molding of automobile plastic parts

Abstract

The invention discloses a cooling device and method in injection molding of automobile plastic parts, and belongs to the technical field of injection cooling, the cooling device comprises an injection molding machine frame, a fixed mold plate, a movable mold plate, a cooling unit and a mold closing pushing unit, the fixed mold plate is vertically fixed on one side of the upper end face of the injection molding machine frame, and the movable mold plate is vertically fixed on the other side of the injection molding machine frame; a mold closing pushing unit is horizontally fixed on the other side of the upper end face of the injection molding rack, and the output end of the mold closing pushing unit is connected with the movable mold plate; the cooling unit is fixed to the end face of the side, away from the fixed mold plate, of the movable mold plate. The cooling unit comprises a cooling plate which is assembled on the movable mold plate in parallel, and a plurality of cooling columns are uniformly distributed on one side of the cooling plate; the multiple cooling columns can be independently controlled to rapidly cool related positions so as to accurately and rapidly cool special forming parts, and it is ensured that key areas reach the needed cooling temperature; and the cooling plate can achieve overall cooling, the cooling direction is adjusted according to the part forming requirement, and the cooling effect is further improved.

Description

Technical Field

[0001] The invention belongs to the technical field of injection molding cooling, and in particular relates to a cooling device and a method for injection molding of automobile plastic parts. Background Art

[0002] Injection molding is a production technology widely used in automobile manufacturing, especially for mass production of plastic parts with complex shapes and high precision requirements. The process injects molten plastic material into the mold cavity, cools and solidifies in the mold to form the desired parts;

[0003] The cooling stage is a key link in the injection molding process, which directly affects product quality, production efficiency and cost control. At present, in the injection molding of automotive parts, the common cooling method is to use circulating water to take away the heat of the mold to achieve rapid cooling. However, although this one-time cooling method has a strong overall cooling effect, it still maintains a high temperature for special molding parts due to insufficient cooling, resulting in continued shrinkage or incomplete solidification of the material in this area.

[0004] These parts are prone to warping, distortion or shape changes, affecting the overall dimensional accuracy and assembly performance of the parts.

[0005] Therefore, it is necessary to provide a cooling device and method for the injection molding of automobile plastic parts to solve the problems raised in the above background technology. Summary of the invention

[0006] To achieve the above-mentioned object, the present invention provides the following technical solution: a cooling device for injection molding of automobile plastic parts, comprising an injection molding frame, a fixed mold plate, a movable mold plate, a cooling unit and a mold clamping and pushing unit, wherein the fixed mold plate is vertically fixed to one side of the upper end surface of the injection molding frame, the movable mold plate is arranged parallel to the fixed mold plate and is slidably mounted with the injection molding frame, the mold clamping and pushing unit is horizontally fixed to the other side of the upper end surface of the injection molding frame, and the output end of the mold clamping and pushing unit is connected to the movable mold plate;

[0007] The cooling unit is fixed to an end surface of the movable platen away from the fixed platen;

[0008] The cooling unit includes a cooling plate, which is assembled in parallel on the moving template. A plurality of cooling columns are evenly distributed on one side of the cooling plate, and guide grooves corresponding to the cooling columns are opened in the moving template. A guide plate is fixed on the other side of the cooling plate, and a cooling pipe is horizontally fixed in the middle of the guide plate. One end of the cooling pipe is slidably connected to the mold pushing unit.

[0009] Preferably, a liquid inlet pipe and a liquid discharge pipe are fixed in the guide plate, a plurality of first branch pipes are connected to the liquid inlet pipe, a plurality of second branch pipes are connected to the liquid discharge pipe, and the other ends of the first branch pipes and the second branch pipes are connected to each cooling column;

[0010] The outside of the liquid inlet pipe is connected with a coolant delivery pipe and a hot oil pipe through a tee.

[0011] Preferably, a heat transfer sleeve is provided on the coaxial sliding sleeve at one end of the cooling column, an inner flow tube is provided at the center of the heat transfer sleeve, and a guide cavity is provided in the cooling column, a through hole is provided on the side wall of the inner flow tube located in the guide cavity, and the second branch pipe is connected to the guide cavity;

[0012] A valve plug is fixed on the side wall of the inner flow tube, and a valve ring is fixed in the cooling column. The valve plug and the valve ring are slidably matched, and a shaft rod is slidably connected in the cooling column.

[0013] Preferably, an electromagnetic driver is fixed to the other end of the cooling column, and a magnetic piston is fixed to the end of the shaft; a compression spring is connected to one side of the magnetic piston.

[0014] Preferably, the inner flow tube is rotatably connected to the heat transfer sleeve, a plurality of pin points are distributed on the side wall of the heat transfer sleeve, and a spoiler sleeve is provided at one end of the inner flow tube located inside the heat transfer sleeve;

[0015] A guide ring is fixed inside the cooling column, an inclined groove is opened on the side wall of the guide ring, a connecting shaft is rotatably connected to the shaft rod, the inner flow tube is fixed to the connecting shaft, a pin is fixed on the side wall of the connecting shaft, and the pin is slidably arranged along the inclined groove.

[0016] Preferably, a plurality of fine channels are distributed circumferentially on the outer wall of the heat transfer sleeve, and the cross section of each fine channel is a U-shaped structure;

[0017] The outer wall of the heat transfer sleeve is in sliding and sealing contact with the guide groove, and the space between the heat transfer sleeve and the guide groove is pre-filled with heat transfer oil;

[0018] A direct current hole is provided on the side wall of the heat transfer sleeve at each narrow channel, a cavity is provided in the middle of the lower end surface of the heat transfer sleeve, and each direct current hole is connected to the cavity;

[0019] A sealing disk is fixed in the guide groove, and the sealing disk is slidably connected with the cavity. A partition disk is fixed at the port of the cavity, and a plurality of one-way holes are opened on the partition disk.

[0020] Preferably, the heat transfer sleeve slides axially back and forth along with the electromagnetic driver under the impetus of electromagnetic force.

[0021] Preferably, a cooling channel is provided in the middle of the cooling plate, and one end of the cooling pipe is connected to the cooling channel;

[0022] The cooling plate is evenly divided into a plurality of flow cavities outside the cooling channel, and a plurality of radial plates are arranged and fixed in each of the flow cavities. The cross section of the radial plates is an arc-shaped structure, and a plurality of radial holes are opened on the radial plates.

[0023] Drainage plates are fixed between the runoff plates.

[0024] Preferably, a plurality of fixing holes are opened on the outer side wall of the cooling plate, and the fixing holes are sealedly connected to the outside of the fixing holes with an outer tube group, and each of the outer tube groups is connected to an inlet pipe and an outlet pipe.

[0025] Preferably, the cooling method in the injection molding of automobile plastic parts comprises the following steps:

[0026] S1. Mold closing and injection molding. The molten plastic enters the injection molding machine frame through the hopper. The movable mold plate is driven by the mold closing push unit to approach the fixed mold plate and complete the mold closing. The high-temperature hot oil is transported to each cooling column through the liquid inlet pipe to preheat the movable mold plate. Then the molten plastic is injected into the mold cavity through the injection molding machine frame. After it is fully filled, a certain pressure is maintained to make the plastic evenly distributed and preliminarily compacted.

[0027] S2. Rapid cooling: According to the special forming positions of the formed automobile parts, such as reinforcing ribs and supporting structures, the cooling columns at the corresponding positions are used to rapidly cool them down. The coolant enters the cooling column through the liquid inlet pipe. The cooling column at the corresponding position is controlled by the electromagnetic driver to separate the valve plug and valve ring on the inner flow tube, and the coolant flows out from the end of the inner flow tube to achieve circulation. At the same time, the electromagnetic driver controls the inner flow tube to move back and forth at high frequency, and the heat transfer sleeve can slide synchronously with the inner flow tube, so that the heat transfer oil fully flows in the fine channels of the heat transfer sleeve, and the coolant flowing inside the cooling column quickly takes away the heat, so that these areas are quickly cooled, initially finalized and thermal stress is reduced;

[0028] S3. Overall cooling, the cooling column stops cooling. According to the requirements of component cooling and molding, the cooling is gradually carried out from the center to the outside or from the outside to the center. The coolant enters the cooling plate and diffuses and flows in the flow cavity to ensure uniform cooling and no excessive cooling that causes stress concentration. After the predetermined cooling time is reached, the cooling system is turned off;

[0029] S4. The mold pushing unit moves in the reverse direction, so that the movable mold plate is separated from the fixed mold plate, and the molded plastic parts are taken out.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The cooling plate used in the present invention can realize the overall cooling of the moving mold plate on the one hand, and on the other hand, the multiple cooling columns distributed on its end face can be independently controlled to perform rapid cooling of relevant positions, so that during the injection cooling process, special molding parts can be accurately and rapidly cooled to ensure that these key areas reach the required cooling temperature; wherein, the cooling plate is evenly divided into multiple flow chambers, each flow chamber is provided with a flow plate, and multiple outer tube groups are distributed outside the cooling plate, so that during the overall cooling process, the cooling liquid can be transported to the cooling plate through each outer tube group to achieve gradual cooling from the outside to the center, and the cooling liquid can be transported to the cooling plate through the cooling channel to achieve gradual cooling from the center to the outside, which not only ensures that the coolant is evenly distributed inside the cooling plate, but also can adjust the cooling direction according to the molding requirements of the parts, reducing the cooling blind area and further improving the cooling effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0033] Figure 2 for Figure 1 A schematic diagram of the structure enlargement in the middle;

[0034] Figure 3 It is a schematic diagram of the structure of the cooling plate and the cooling column in the present invention;

[0035] Figure 4 It is a structural schematic diagram of the cooling unit in the present invention;

[0036] Figure 5 It is a schematic diagram of the internal structure of the cooling column in the present invention;

[0037] Figure 6 for Figure 5 A magnified schematic diagram of the structure at B in the middle;

[0038] Figure 7 It is a schematic diagram of the structure of the heat transfer sleeve in the present invention;

[0039] Figure 8 It is a cross-sectional view of the cooling plate in the present invention.

[0040] In the figure: 1. injection molding machine frame; 11. fixed plate; 12. movable plate; 13. mold pushing unit; 14. guide groove; 2. cooling unit; 21. guide plate; 22. cooling pipe; 23. liquid inlet pipe; 24. liquid discharge pipe; 3. cooling plate; 31. cooling channel; 32. radial plate; 33. radial hole; 34. guide plate; 35. fixed hole; 36. outer tube group; 37. inlet pipe; 38. outlet pipe; 4. cooling column; 41. inner flow pipe; 42. guide cavity; 43. valve plug; 44. connecting shaft; 45. shaft rod; 46. electromagnetic drive; 47. guide ring; 5. heat transfer sleeve; 51. needle point; 52. spoiler sleeve; 53. fine channel; 54. direct current hole; 55. hole cavity; 56. sealing disk; 57. one-way row hole. DETAILED DESCRIPTION

[0041] See also Figure 1-Figure 8 In an embodiment of the present invention, a cooling device for injection molding of automobile plastic parts comprises an injection molding frame 1, a fixed mold plate 11, a movable mold plate 12, a cooling unit 2 and a mold clamping propulsion unit 13, wherein the fixed mold plate 11 is vertically fixed to one side of the upper end surface of the injection molding frame 1, the movable mold plate 12 is arranged parallel to the fixed mold plate 11 and is slidably installed with the injection molding frame 1, and the movable mold plate 12 can be sealed and slidably assembled with the fixed mold plate 11, thereby forming a sealed injection molding cavity for automobile parts; the mold clamping propulsion unit 13 is horizontally fixed to the other side of the upper end surface of the injection molding frame 1, and the output end of the mold clamping propulsion unit 13 is connected to the movable mold plate 12, and the mold clamping propulsion unit 13 is mainly used to provide a driving force for horizontal displacement of the movable mold plate 12;

[0042] The cooling unit 2 is fixed to an end surface of the movable plate 12 away from the fixed plate 11;

[0043] The cooling unit 2 includes a cooling plate 3, which is assembled in parallel on the movable template 12, and can be assembled in close contact with the cooling plate 3, so that heat can be quickly transferred from the movable template 12 to the cooling plate 3, and then the heat is taken away by the coolant in the cooling plate 3. A plurality of cooling columns 4 are evenly distributed on one side of the cooling plate 3, and a guide groove 14 corresponding to the cooling columns 4 is opened in the movable template 12, and the cooling columns 4 can be plugged and assembled in the guide groove 14 one by one; a guide plate 21 is fixed on the other side of the cooling plate 3, and a cooling pipe 22 is horizontally fixed in the middle of the guide plate 21, and one end of the cooling pipe 22 is slidably connected in the mold pushing unit 13, and the cooling pipe 22 is connected to an external liquid supply pump for pumping the coolant into the cooling plate 3 through the cooling pipe 22.

[0044] In this embodiment, a liquid inlet pipe 23 and a liquid discharge pipe 24 are fixed in the guide plate 21, the liquid inlet pipe 23 is connected to a plurality of first branch pipes, the liquid discharge pipe 24 is connected to a plurality of second branch pipes, and the other ends of the first branch pipes and the second branch pipes are connected to the cooling columns 4; therefore, the liquid inlet pipe 23 can transport the coolant to the cooling columns 4 through the first branch pipes, and the coolant is circulated and discharged into the liquid discharge pipe 24 through the second branch pipes;

[0045] The liquid inlet pipe 23 is connected to a coolant delivery pipe and a hot oil pipe through a tee (not shown in the figure), wherein the coolant delivery pipe and the cooling pipe 22 are independently arranged, and can respectively deliver coolants of different temperatures, and the hot oil pipe is mainly used to provide high-temperature hot oil, so that the movable template 12 can be internally preheated through each cooling column 4 at the initial stage of injection molding, so that the movable template 12 can reach the working temperature faster, thereby improving the flow performance of the molten plastic in the injection cavity and reducing defects such as bubbles and shrinkage holes that may occur during the filling process.

[0046] As a preferred embodiment, a heat transfer sleeve 5 is coaxially provided on one end of the cooling column 4, an inner flow tube 41 is provided at the center of the heat transfer sleeve 5, and a guide cavity 42 is provided in the cooling column 4, a through hole is provided on the side wall of the inner flow tube 41 located in the guide cavity 42, and the second branch pipe is connected to the guide cavity 42; the coolant can enter the cooling column 4 and then flow into the heat transfer sleeve 5, and then enter the guide cavity 42 through the through hole of the inner flow tube 41, so that it is discharged by the second branch pipe outside the guide cavity 42, so as to realize the circulation of the coolant;

[0047] A valve plug 43 is fixed on the side wall of the inner flow tube 41, and a valve ring is fixed in the cooling column 4. The valve plug 43 is slidably matched with the valve ring. A shaft rod 45 is slidably connected in the cooling column 4. When the valve plug 43 is sealed with the valve ring, the coolant cannot flow into the cooling column 4 for circulation, thereby realizing independent adjustment of each cooling column 4, so that the cooling column 4 at the corresponding position can be controlled to cool the moving template 12 during cooling molding.

[0048] In this embodiment, an electromagnetic driver 46 is fixed to the other end of the cooling column 4, and a magnetic piston is fixed to the end of the shaft rod 45; a compression spring is connected to one side of the magnetic piston, and the compression spring pushes the shaft rod 45 away from the electromagnetic driver 46 under the action of elastic force, so that the valve plug 43 is sealed with the valve ring in the initial state.

[0049] In this embodiment, the inner flow tube 41 is rotatably connected to the heat transfer sleeve 5, a plurality of pin points 51 are distributed on the side wall of the heat transfer sleeve 5, and a spoiler sleeve 52 is sleeved on one end of the inner flow tube 41 located inside the heat transfer sleeve 5;

[0050] A guide ring 47 is fixed inside the cooling column 4, and an inclined groove is provided on the side wall of the guide ring 47. A connecting shaft 44 is rotatably connected to the shaft rod 45, and the inner flow tube 41 is fixed to the connecting shaft 44. A pin is fixed on the side wall of the connecting shaft 44, and the pin is slidably arranged along the inclined groove. Therefore, when the shaft rod 45 is in axial sliding adjustment, it can synchronously control the heat transfer sleeve 5 to slide. At this time, the shaft rod 45 can be deflected by the sliding action of the pin and the inclined groove on the connecting shaft 44, so that the spoiler sleeve 52 on the shaft rod 45 spurs the coolant in the heat transfer sleeve 5, thereby improving the heat exchange efficiency and accelerating the heat transfer speed. Therefore, in the extremely fast cooling of the cooling column, the electromagnetic driver 46 first drives the shaft 45 to slide in the direction close to the electromagnetic driver 46 in the first stage, so that the valve plug 43 on the shaft 45 is separated from the valve ring. At this time, the coolant flows into the cooling column 4, and then the electromagnetic driver 46 uses a controller (such as a PLC or a dedicated motion controller) to accurately control the current direction and intensity of the electromagnetic driver 46 in the second stage. By changing the direction of the current, the electromagnetic driver 46 generates electromagnetic forces in both positive and negative directions, thereby driving the shaft 45 to slide back and forth. At this time, the coolant can flow efficiently in the heat transfer sleeve 5 for heat exchange.

[0051] In this embodiment, a plurality of fine channels 53 are distributed circumferentially on the outer wall of the heat transfer sleeve 5, and the cross section of each fine channel 53 is a U-shaped structure;

[0052] The outer wall of the heat transfer sleeve 5 is in sliding and sealing contact with the guide groove 14, and the space between the heat transfer sleeve 5 and the guide groove 14 is pre-filled with heat transfer oil; the heat transfer oil can quickly transfer the heat of the movable plate 12 to the heat transfer sleeve 5;

[0053] A direct current hole 54 is provided on the side wall of the heat transfer sleeve 5 at each narrow channel 53, and a cavity 55 is provided in the middle of the lower end surface of the heat transfer sleeve 5, and each direct current hole 54 is connected to the cavity 55;

[0054] A sealing plate 56 is fixed in the guide groove 14, and the sealing plate 56 is slidably connected to the cavity 55. A partition plate is fixed at the end of the cavity 55, and a plurality of one-way row holes 57 are opened on the partition plate. Therefore, in the second stage of the operation of the electromagnetic driver 46, it can push the shaft rod 45 to slide back and forth, and the heat transfer sleeve 5 can be displaced synchronously with the shaft rod 45. At this time, when the heat transfer sleeve 5 slides to the side away from the electromagnetic driver 46, the heat transfer sleeve 5 can press the heat transfer oil into the narrow channel 53, and the heat transfer oil enters the cavity 55 through the direct current hole 54. When the heat transfer sleeve 5 slides to the side close to the electromagnetic driver 46, the heat transfer oil is squeezed by the sealing plate 56 and discharged into the guide groove 14 through the one-way row holes 57.

[0055] As a preferred embodiment, the heat transfer sleeve 5 slides axially back and forth along with the electromagnetic driver 46 under the push of electromagnetic force.

[0056] In this embodiment, a cooling channel 31 is opened in the middle of the cooling plate 3, and one end of the cooling pipe 22 is connected to the cooling channel 31;

[0057] The cooling plate 3 is evenly divided into a plurality of flow chambers outside the cooling channel 31, and a plurality of radial plates 32 are arranged and fixed in each of the flow chambers. The cross section of the radial plates 32 is an arc-shaped structure, and a plurality of radial holes 33 are opened on the radial plates 32;

[0058] The guide plates 34 are fixed between the flow-guiding plates 32 , and the plurality of guide plates 34 cooperate with each other to make the coolant flow in a serpentine shape.

[0059] In this embodiment, a plurality of fixing holes 35 are provided on the outer side wall of the cooling plate 3, and the fixing holes 35 are sealed and connected to the outer side of the fixing holes 35, and each of the outer tube groups 36 is connected to an inlet pipe 37 and an outlet pipe 38. Therefore, on the one hand, the inlet pipe 37 can deliver the coolant into the cooling plate 3 through the outer tube group 36. At this time, the coolant passes through each flow cavity and is finally discharged from the cooling channel 31, thereby realizing an overall cooling and cooling method of gradually cooling from the outside to the center, so as to first cool the edge part of the mold and then gradually cool to the center. This method is suitable for automotive parts whose edges are prone to overheating or need to cool the edges first. On the other hand, the coolant can be sent into the cooling plate 3 through the cooling channel 31. At this time, the coolant passes through each flow cavity and is finally discharged from the exhaust pipe 38 on each outer tube group 36, thereby realizing an overall cooling and cooling method of gradually cooling from the center to the outside. The center part of the mold is cooled first, and then gradually expanded to the edge. This method is suitable for automotive parts that are thicker or prone to overheating in the center, such as: door inner panels, engine hoods, etc. Since the center part is prone to accumulate heat during the injection molding process, cooling the center part first can effectively prevent local overheating, reduce thermal stress and material deformation, and ensure its dimensional accuracy and surface quality.

[0060] A cooling method for injection molding of automobile plastic parts comprises the following steps:

[0061] S1. Mold closing and injection molding, the molten plastic enters the injection molding frame 1 through the hopper, and the movable mold plate 12 is driven by the mold closing push unit 13 to approach the fixed mold plate 11 and complete the mold closing; high-temperature hot oil is transported to each cooling column 4 through the liquid inlet pipe 23, so as to preheat the movable mold plate 12, and then the molten plastic is injected into the mold cavity through the injection molding frame 1. After it is completely filled, a certain pressure is maintained to make the plastic evenly distributed and preliminarily compacted;

[0062] S2. Rapid cooling. According to the special forming positions of the formed automobile parts, such as reinforcing ribs and supporting structures, the cooling columns 4 at the corresponding positions are used to rapidly cool and reduce the temperature. The coolant enters the cooling columns 4 through the liquid inlet pipe 23. The cooling columns 4 at the corresponding positions are controlled by the electromagnetic driver 46 to separate the valve plug 43 on the inner flow tube 41 from the valve ring, and the coolant flows out from the end of the inner flow tube 41 to achieve circulation. At the same time, the electromagnetic driver 46 controls and drives the inner flow tube 41 to move back and forth at high frequency, and the heat transfer sleeve 5 can slide synchronously with the inner flow tube 41, so that the heat transfer oil fully flows in the fine channels 53 of the heat transfer sleeve 5, and the coolant flowing inside the cooling column 4 quickly takes away the heat, so that these areas are quickly cooled, initially finalized and thermal stress is reduced. The working frequency of the inner flow tube 41 is 20Hz-50Hz, so that the flow rate of the heat transfer oil can be adjusted in different frequency adjustments.

[0063] S3. Overall cooling, the cooling column 4 stops cooling operation, and according to the requirements of component cooling and molding, a gradual cooling method from the center to the outside or from the outside to the center is adopted. The coolant enters the flow cavity of the cooling plate 3 and fully diffuses and flows to ensure uniform cooling and no excessive cooling to cause stress concentration. After the predetermined cooling time is reached, the cooling system is turned off; therefore, the cooling process is divided into two stages and specifically adjusted according to the cooling requirements of component molding, which effectively improves the cooling molding efficiency, reduces the cooling blind area, and further improves the cooling effect;

[0064] S4. The mold pushing unit 13 moves in the reverse direction, so that the movable mold plate 12 is separated from the fixed mold plate 11, and the molded plastic parts are taken out.

[0065] What is described above is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A cooling device for injection molding of automobile plastic parts, comprising an injection molding machine frame (1), a fixed mold plate (11), a movable mold plate (12), a cooling unit (2) and a mold clamping and pushing unit (13), characterized in that: The fixed plate (11) is vertically fixed to one side of the upper end surface of the injection molding machine frame (1); the movable plate (12) is arranged parallel to the fixed plate (11) and is slidably mounted with the injection molding machine frame (1); a mold clamping propulsion unit (13) is horizontally fixed to the other side of the upper end surface of the injection molding machine frame (1); and the output end of the mold clamping propulsion unit (13) is connected to the movable plate (12); The cooling unit (2) is fixed to an end surface of the movable plate (12) away from the fixed plate (11); The cooling unit (2) includes a cooling plate (3) which is assembled in parallel on the movable plate (12); a plurality of cooling columns (4) are evenly distributed on one side of the cooling plate (3); and a guide groove (14) corresponding to the cooling columns (4) is opened in the movable plate (12); a guide plate (21) is fixed on the other side of the cooling plate (3); a cooling pipe (22) is fixed horizontally in the middle of the guide plate (21), and one end of the cooling pipe (22) is slidably connected to the mold pushing unit (13).

2. The cooling device for injection molding of automobile plastic parts according to claim 1, characterized in that: A liquid inlet pipe (23) and a liquid discharge pipe (24) are fixed in the guide plate (21); a plurality of first branch pipes are connected to the liquid inlet pipe (23); a plurality of second branch pipes are connected to the liquid discharge pipe (24); and the other ends of the first branch pipes and the second branch pipes are connected to each cooling column (4); The liquid inlet pipe (23) is externally connected to a coolant delivery pipe and a hot oil pipe via a tee.

3. The cooling device for injection molding of automobile plastic parts according to claim 2, characterized in that: A heat transfer sleeve (5) is provided on a coaxial sliding sleeve at one end of the cooling column (4), an inner flow tube (41) is provided at the center of the heat transfer sleeve (5), and a guide cavity (42) is provided in the cooling column (4), a through hole is provided on the side wall of the inner flow tube (41) located in the guide cavity (42), and the second branch pipe is connected to the guide cavity (42); A valve plug (43) is fixed on the side wall of the inner flow tube (41), and a valve ring is fixed in the cooling column (4). The valve plug (43) and the valve ring are slidably matched, and a shaft (45) is slidably connected in the cooling column (4).

4. The cooling device for injection molding of automobile plastic parts according to claim 3, characterized in that: An electromagnetic driver (46) is fixed to the other end of the cooling column (4), and a magnetic piston is fixed to the end of the shaft (45); one side of the magnetic piston is connected to a compression spring.

5. The cooling device for injection molding of automobile plastic parts according to claim 4, characterized in that: The inner flow tube (41) is rotatably connected to the heat transfer sleeve (5), a plurality of pin points (51) are distributed on the side wall of the heat transfer sleeve (5), and one end of the inner flow tube (41) located inside the heat transfer sleeve (5) is provided with a spoiler sleeve (52); A guide ring (47) is fixed inside the cooling column (4), and an inclined groove is provided on the side wall of the guide ring (47). A connecting shaft (44) is rotatably connected to the shaft rod (45), and the inner flow tube (41) is fixed to the connecting shaft (44). A pin is fixed on the side wall of the connecting shaft (44), and the pin is slidably arranged along the inclined groove.

6. The cooling device for injection molding of automobile plastic parts according to claim 5, characterized in that: A plurality of fine channels (53) are distributed circumferentially on the outer wall of the heat transfer sleeve (5), and the cross section of each fine channel (53) is a U-shaped structure; The outer wall of the heat transfer sleeve (5) is in sliding and sealing contact with the guide groove (14), and heat transfer oil is pre-filled between the heat transfer sleeve (5) and the guide groove (14); A direct current hole (54) is provided on the side wall of the heat transfer sleeve (5) at each narrow channel (53), a cavity (55) is provided in the middle of the lower end surface of the heat transfer sleeve (5), and each direct current hole (54) is connected to the cavity (55); A sealing disk (56) is fixed in the guide groove (14), and the sealing disk (56) is slidably connected to the cavity (55). A partition disk is fixed at the end of the cavity (55), and a plurality of one-way holes (57) are formed on the partition disk.

7. The cooling device for injection molding of automobile plastic parts according to claim 6, characterized in that: The heat transfer sleeve (5) slides axially back and forth under the push of the electromagnetic force of the electromagnetic driver (46).

8. The cooling device for injection molding of automobile plastic parts according to claim 1, characterized in that: A cooling channel (31) is provided in the middle of the cooling plate (3), and one end of the cooling pipe (22) is connected to the cooling channel (31); The cooling plate (3) is divided into a plurality of flow cavities outside the cooling channel (31), and a plurality of runoff plates (32) are arranged and fixed in each of the flow cavities. The cross section of the runoff plates (32) is an arc-shaped structure, and a plurality of runoff holes (33) are formed on the runoff plates (32); A flow guide plate (34) is fixed between the runoff plates (32).

9. The cooling device for injection molding of automobile plastic parts according to claim 1, characterized in that: A plurality of fixing holes (35) are provided on the outer side wall of the cooling plate (3), and the fixing holes (35) are all sealedly connected to an outer tube group (36), and each outer tube group (36) is connected to an inlet pipe (37) and an outlet pipe (38).

10. A cooling method for injection molding of automobile plastic parts, which uses the cooling device for injection molding of automobile plastic parts according to any one of claims 6 to 7, characterized in that: The following steps are involved: S1. Mold closing and injection molding, the molten plastic enters the injection molding machine frame (1) through the hopper, and the movable platen (12) is driven by the mold closing push unit (13) to approach the fixed platen (11) and complete the mold closing; high-temperature hot oil is delivered to each cooling column (4) through the liquid inlet pipe (23), thereby preheating the movable platen (12), and then the molten plastic is injected into the mold cavity through the injection molding machine frame (1). After it is completely filled, a certain pressure is maintained to make the plastic evenly distributed and initially compacted; S2. Rapid cooling. According to the special forming position of the formed automobile parts, the cooling column (4) at the corresponding position is used to rapidly cool and reduce the temperature thereof, wherein the coolant enters the cooling column (4) through the liquid inlet pipe (23). The cooling column (4) at the corresponding position is controlled by the electromagnetic driver (46) to separate the valve plug (43) on the inner flow tube (41) from the valve ring, and the coolant flows out from the end of the inner flow tube (41) to achieve circulation; at the same time, the electromagnetic driver (46) controls the inner flow tube (41) to move back and forth at high frequency, and the heat transfer sleeve (5) can slide synchronously with the inner flow tube (41), so that the heat transfer oil fully flows in the various fine channels (53) of the heat transfer sleeve (5), and the coolant flowing inside the cooling column (4) quickly takes away the heat, so that these areas are quickly cooled, the initial shaping is completed, and the thermal stress is reduced; S3. Overall cooling, the cooling column (4) stops cooling. According to the requirements of the component cooling and molding, a gradual cooling method is adopted from the center to the outside or from the outside to the center. The coolant enters the flow cavity of the cooling plate (3) and fully diffuses and flows to ensure uniform cooling and no excessive cooling causing stress concentration. After the predetermined cooling time is reached, the cooling system is turned off. S4. The mold pushing unit (13) moves in the reverse direction, so that the movable mold plate (12) is separated from the fixed mold plate (11), and the molded plastic parts are taken out.

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