Short cycle injection molding method for PVC drain pipes

Abstract

The application discloses a short-period injection molding method for PVC drainage pipes and relates to the technical field of PVC pipe production; the method comprises the following steps of S1, raw material preparation, S2, mold preparation, S3, raw material melting, S4, injection molding, S5, mold opening, S6, inspection, and S7, packaging; in the application, the PVC drainage pipe prepared through S1-S7 has high production efficiency, stable product quality, and recycling use, so that the overall quality of the PVC drainage pipe is improved; the movable mold base is separated from the fixed mold base through driving, and the movable mold base is turned over in the process, so that the other side of the mold cavity of the movable mold base faces the fixed mold base, the automatic mold changing in the PVC drainage pipe injection molding process is conveniently realized, and the production efficiency of the PVC drainage pipe is effectively improved.

Description

Technical Field

[0001] This invention relates to the field of PVC pipe fittings manufacturing technology, specifically a short-cycle injection molding method for PVC drainage pipes. Background Technology

[0002] PVC drainage pipes are made from sanitary-grade polyvinyl chloride resin as the main raw material, and the production of pipes and fittings is completed through processes such as cooling, curing, shaping, inspection, and packaging.

[0003] However, existing technologies still have some drawbacks when injection molding PVC drainage pipes:

[0004] 1. In the existing technology for injection molding PVC drainage pipes, it is inconvenient to automatically change the moving mold base during the injection molding process. After one molding, the demolded moving mold base needs to be cooled. After the moving mold base is cooled, the mold is closed and injection is performed. Since the whole process is in a shutdown state, it will have a certain impact on the production efficiency of PVC drainage pipes.

[0005] 2. At the same time, when the existing technology is used to injection mold PVC drainage pipes, the injection molding equipment is not convenient to perform preliminary cooling on the newly formed PVC drainage pipes, which leads to the subsequent cooling process requiring a lot of time, resulting in low cooling efficiency of PVC drainage pipes. In addition, the high temperature of PVC drainage pipes during the subsequent cooling process can easily cause burns to workers.

[0006] To address the aforementioned problems, the inventors proposed a short-cycle injection molding method for PVC drainage pipes. Summary of the Invention

[0007] To address the problems of inconvenience in automatically changing the moving mold base and inconvenience in initially cooling the newly formed PVC drainage pipe during injection molding, the present invention aims to provide a short-cycle injection molding method for PVC drainage pipes.

[0008] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a short-cycle injection molding method for PVC drainage pipes, comprising the following steps:

[0009] S1. Raw material preparation

[0010] PVC resin granules, plasticizer, stabilizer, lubricant and filler are added to the hopper of the injection molding equipment in proportion, and the raw materials in the hopper are mixed.

[0011] S2, Mold Preparation

[0012] Select a matching mold based on the shape and outer pipe size of the PVC drainage pipe, and install the mold on the mold locking device of the injection molding equipment;

[0013] S3, Raw material melting

[0014] The mixed raw materials are fed into the screw of the injection molding equipment, where they are melted by the rotation and heating of the screw.

[0015] S4, Injection Molding

[0016] Molten raw materials are injected into the cavity of a mold through the injection device of an injection molding machine, and then cooled and solidified to obtain PVC drainage pipes;

[0017] S5, Demolding

[0018] After the PVC drainage pipe is injection molded, the mold is opened, the cooled and cured PVC drainage pipe is taken out, and then cooled, cleaned and trimmed.

[0019] S6, Inspection

[0020] Perform visual and dimensional inspections on injection-molded PVC drainage pipes to ensure that product quality meets production requirements;

[0021] S7, Packaging

[0022] Qualified PVC drainage pipes are bagged and packaged.

[0023] Preferably, the PVC resin granules are polyvinyl chloride resin.

[0024] Preferably, the screw filling control time of the injection molding equipment is 1.4s, the temperature of the mold is 25°C, and the temperature of the molten raw material is 205°C.

[0025] Preferably, the injection molding equipment includes an injection molding machine housing, an injection unit, and an injection molding unit. The injection unit and the injection molding unit are installed on the upper surface of the injection molding machine housing. The injection molding unit includes a chassis, which is fixedly installed on the upper surface of the injection molding machine housing. A fixed mold base is fixedly installed on the side wall of the chassis, and a mold cavity is provided on one side of the fixed mold base. A movable mold base is slidably provided on the side wall of the chassis, and mold cavities are provided on both sides of the movable mold base. One side of the movable mold base and one side of the fixed mold base are in movable contact. A transfer storage box is fixedly installed at the bottom of the chassis. A plurality of evenly distributed heat dissipation slots are provided on both sides of the transfer storage box. A guide plate is fixedly installed on the side wall of the transfer storage box, and the guide plate is inclined. A discharge hopper is fixedly installed on one side of the transfer storage box. A mold changing mechanism and a flipping mechanism are respectively provided on the chassis, and a cooling mechanism is provided inside the transfer storage box.

[0026] Preferably, the mold changing mechanism includes two L-shaped moving rods, and moving seats are fixedly installed on both sides of the moving mold base. The lower surfaces of the two moving seats are provided with arc-shaped grooves. One end of one of the L-shaped moving rods is in movable contact with the middle of the arc-shaped groove. Two first rotating rods are rotatably installed on both sides of the chassis. One end of each of the four first rotating rods is fixedly installed with a transmission wheel. A transmission belt is installed between two adjacent transmission wheels. The other end of one L-shaped moving rod is fixedly connected to one end of one transmission belt, and the other end of the other L-shaped moving rod is fixedly connected to one end of another transmission belt. A servo motor is fixedly installed on one side of the chassis, and the drive output end of the servo motor is fixedly connected to the other end of one of the first rotating rods.

[0027] Preferably, the upper surface of the chassis is provided with a guide groove, one end of the guide groove is slidably mounted with a guide block, and the lower surface of the guide block is rotatably provided with the moving mold base.

[0028] Preferably, a first transmission rod is rotatably mounted on the side of the chassis near the servo motor. A transmission gear is fixedly mounted on the middle of one of the first rotating rods and the middle of the first transmission rod, and the two transmission gears mesh with each other. A second transmission rod is rotatably mounted on the upper surface of the chassis. A first synchronous pulley is fixedly mounted on one end of the first transmission rod and one end of the second transmission rod. A first synchronous belt is driven between the two first synchronous pulleys. A second synchronous pulley is fixedly mounted on the other end of the second transmission rod and the other end of the other first rotating rod. A second synchronous belt is driven between the two second synchronous pulleys.

[0029] Preferably, the flipping mechanism includes a second rotating rod, which is rotatably connected to the upper surface of the housing. A positive magnet is fixedly installed at one end of the second rotating rod. A connecting shaft is rotatably installed on the upper surface of the guide block. A negative magnet is fixedly installed at the end of the connecting shaft away from the guide block. The positive magnet and the negative magnet are attracted to each other. A rotating shaft is fixedly installed on the upper surface of the moving mold base. The end of the connecting shaft away from the negative magnet and the end of the rotating shaft away from the moving mold base are fixedly connected. A first bevel gear is fixedly installed in the middle of the second transmission rod and at the end of the second rotating rod away from the positive magnet. The two first bevel gears mesh with each other.

[0030] Preferably, the cooling mechanism includes side plates, two side plates are fixedly installed on the bottom wall of the transfer storage box, a rotating shaft is rotatably installed between the two side plates, a connecting frame is fixedly installed in the middle of the rotating shaft, a fan is fixedly installed at one end of the connecting frame, a plurality of evenly distributed ventilation slots are opened on the surface of the guide plate, the fan is located below the guide plate, and a swing plate is fixedly installed at one end of the rotating shaft.

[0031] Preferably, a third rotating rod is rotatably mounted inside the injection molding machine housing. A crank is fixedly mounted at one end of the third rotating rod, and a connecting rod is fixedly mounted at one end of the crank. A strip groove is formed on the swing plate. The end of the connecting rod away from the crank and the end of the strip groove are in movable contact. A third transmission rod is rotatably mounted on the side wall of the injection molding machine housing. A second bevel gear is fixedly mounted at one end of the third transmission rod and in the middle of the third rotating rod. The two second bevel gears mesh with each other. A third synchronous pulley is fixedly mounted at the other end of the first transmission rod and the other end of the third transmission rod. A third synchronous belt is installed between the two third synchronous pulleys.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] 1. In this invention, the PVC drainage pipes prepared by S1-S7 have high production efficiency, stable product quality, and are recyclable, thereby improving the overall quality of PVC drainage pipes.

[0034] 2. In this invention, the conformal water channel of the conformal water pipe is injection molded. The local corners inside are thicker, which affects the cycle. Considering that the product can be ejected when it is 50% frozen, the overall flow result is expected to be about 100 seconds. Compared with the effect of conventional water channels, the overall mold flow result is expected to be about 140 seconds, which effectively improves the injection molding efficiency of PVC drainage pipe.

[0035] 3. In this invention, by driving the moving mold base to separate from the fixed mold base, and in the process driving the moving mold base to flip, so that the other side of the mold cavity of the moving mold base faces the fixed mold base, the automatic mold changing in the injection molding process of PVC drainage pipe is conveniently realized, thereby effectively improving the production efficiency of PVC drainage pipe.

[0036] 4. In this invention, by driving a fan to swing back and forth around the axis of the rotating shaft, the fan can comprehensively cool the PVC drain pipe on the guide plate during the swinging process, thereby conveniently realizing the initial cooling of the injection-molded PVC drain pipe, thus effectively improving the cooling efficiency of the PVC drain pipe, and at the same time, preventing workers from being burned by contact with the PVC drain pipe during subsequent operations. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1This is a schematic diagram of the overall structure of the injection molding equipment of the present invention.

[0039] Figure 2 This is another overall structural schematic diagram of the injection molding equipment of the present invention.

[0040] Figure 3 For the present invention Figure 2 Enlarged schematic diagram of part A in the diagram.

[0041] Figure 4 This is a cross-sectional structural diagram of the injection molding machine housing and housing of the present invention.

[0042] Figure 5 This is a schematic diagram of the connection structure between the mold changing mechanism and the flipping mechanism of the present invention and the moving mold base.

[0043] Figure 6 For the present invention Figure 5 Enlarged schematic diagram of part B in the diagram.

[0044] Figure 7 This is a schematic diagram of the separation state of the moving mold base and the fixed mold base, as well as the cutting mechanism of the transfer storage box of the present invention.

[0045] Figure 8 This is a schematic diagram of the connection structure between the mold changing mechanism and the cooling mechanism of the present invention.

[0046] Figure 9 For the present invention Figure 8 Enlarged schematic diagram of part C in the diagram.

[0047] Figure 10 This is a schematic diagram of the structure of the flipping mechanism, guide block, and moving mold base of the present invention.

[0048] Figure 11 This is a schematic diagram of the internal conformal water channel of the PVC water pipe injection molded according to the present invention.

[0049] In the diagram: 1. Injection molding machine housing; 2. Injection unit; 3. Injection molding unit; 31. Chassis; 32. Fixed mold base; 33. Moving mold base; 34. Transfer storage box; 341. Heat dissipation groove; 35. Guide plate; 36. Discharge hopper; 4. Mold changing mechanism; 41. L-shaped moving rod; 42. Moving seat; 43. Arc groove; 44. Guide groove; 45. Guide block; 46. First rotating rod; 47. Transmission wheel; 48. Transmission belt; 49. Servo motor; 51. First transmission rod; 52. Transmission gear; 53. Second transmission rod; 54. First synchronous pulley. 55. First synchronous belt; 56. Second synchronous pulley; 57. Second synchronous belt; 6. Tilting mechanism; 61. Second rotating rod; 62. Positive magnet; 63. Connecting shaft; 64. Negative magnet; 65. Rotating shaft; 67. First bevel gear; 8. Cooling mechanism; 81. Side plate; 82. Rotating shaft; 83. Connecting frame; 84. Fan; 85. Ventilation slot; 86. Swing plate; 87. Third rotating rod; 88. Crank; 89. Connecting rod; 9. Strip groove; 91. Third transmission rod; 92. Second bevel gear; 93. Third synchronous pulley; 94. Third synchronous belt. Detailed Implementation

[0050] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0051] Example: Figure 1-11 As shown, the present invention provides a short-cycle injection molding method for PVC drainage pipes, comprising the following steps:

[0052] S1. Raw material preparation

[0053] PVC resin granules, plasticizer, stabilizer, lubricant and filler are added to the hopper of the injection molding equipment in proportion, and the raw materials in the hopper are mixed.

[0054] S2, Mold Preparation

[0055] Select a matching mold based on the shape and outer pipe size of the PVC drainage pipe, and install the mold on the mold locking device of the injection molding equipment;

[0056] S3, Raw material melting

[0057] The mixed raw materials are fed into the screw of the injection molding equipment, where they are melted by the rotation and heating of the screw.

[0058] S4, Injection Molding

[0059] Molten raw materials are injected into the cavity of a mold through the injection device of an injection molding machine, and then cooled and solidified to obtain PVC drainage pipes;

[0060] S5, Demolding

[0061] After the PVC drainage pipe is injection molded, the mold is opened, the cooled and cured PVC drainage pipe is taken out, and then cooled, cleaned and trimmed.

[0062] S6, Inspection

[0063] Perform visual and dimensional inspections on injection-molded PVC drainage pipes to ensure that product quality meets production requirements;

[0064] S7, Packaging

[0065] Qualified PVC drainage pipes are bagged and packaged.

[0066] The PVC resin granules are polyvinyl chloride resin.

[0067] The screw filling control time of the injection molding equipment is 1.4s, the temperature of the mold is 25℃, and the temperature of the molten raw material is 205℃.

[0068] By adopting the above technical solution, PVC resin granules, plasticizers, stabilizers, lubricants, and fillers are added to the raw materials. A suspension-type loose resin is used, along with a lead salt composite stabilizer. This stabilizer captures HCl produced by the thermal decomposition of PVC, preventing its catalytic degradation. A high-fatty acid metal salt lubricant is used to improve the lubricity of the prepared PVC drainage pipe. Light calcium carbonate filler is used to increase the hardness of the prepared PVC drainage pipe, while also improving its surface gloss and smoothness. DOP is used to improve the flexibility of the prepared PVC drainage pipe and prevent cracking during use. The PVC drainage pipe prepared through these steps has high production efficiency, stable product quality, and is recyclable, thus improving the overall quality of PVC drainage pipes. (Reference) Figure 11 The conformal water pipe with injection molding has thicker internal corners, which affects the cycle time. Considering that the product can be ejected when it is 50% frozen, the overall flow result is expected to have a cycle time of about 100 seconds. Compared with the effect of conventional water pipe, the overall mold flow result is expected to have a cycle time of about 140 seconds, which effectively improves the injection molding efficiency of PVC drainage pipe.

[0069] The injection molding equipment includes an injection molding machine housing 1, an injection unit 2, and an injection molding unit 3. The injection unit 2 and the injection molding unit 3 are installed on the upper surface of the injection molding machine housing 1. The injection molding unit 3 includes a housing 31, which is fixedly installed on the upper surface of the injection molding machine housing 1. A fixed mold base 32 is fixedly installed on the side wall of the housing 31, and a mold cavity is provided on one side of the fixed mold base 32. A movable mold base 33 is slidably provided on the side wall of the housing 31, and mold cavities are provided on both sides of the movable mold base 33. One side of the moving mold base 33 and one side of the fixed mold base 32 are in contact. A transfer storage box 34 is fixedly installed at the bottom of the chassis 31. Several heat dissipation slots 341 are evenly distributed on both sides of the transfer storage box 34. A guide plate 35 is fixedly installed on the side wall of the transfer storage box 34. The guide plate 35 is inclined. A discharge hopper 36 is fixedly installed on one side of the transfer storage box 34. A mold changing mechanism 4 and a flipping mechanism 6 are respectively provided on the chassis 31. A cooling mechanism 8 is provided inside the transfer storage box 34.

[0070] By adopting the above technical solution, during operation, injection unit 2 injects the plasticized molten material into injection unit 3 through the thrust of the screw. The PVC drainage pipe is formed in injection unit 3. This is existing technology and will not be elaborated here. By setting up a transfer storage box 34, guide plate 35, and discharge hopper 36, the injection-molded PVC drainage pipe enters the transfer storage box 34 and is discharged through guide plate 35 and discharge hopper 36. By setting up a heat dissipation groove 341, the high-temperature airflow inside the transfer storage box 34 passes through the heat dissipation groove. 341 is discharged. By setting a mold changing mechanism 4 and a flipping mechanism 6, the mold changing mechanism 4 can make the moving mold base 33 move horizontally, so that the moving mold base 33 can separate or fit with the fixed mold base 32. The flipping mechanism 6 can flip the moving mold base 33 90 degrees after it is separated from the fixed mold base 32, thus facilitating the automatic replacement of the moving mold base 33 and improving the production efficiency of PVC drainage pipes. By setting a cooling mechanism 8, the cooling mechanism 8 performs preliminary cooling on the PVC drainage pipes during the falling process, thereby improving the cooling efficiency of the PVC drainage pipes and preventing the subsequent operators from being burned during operation.

[0071] The mold changing mechanism 4 includes two L-shaped moving rods 41. Moving seats 42 are fixedly installed on both sides of the moving mold base 33. Arc grooves 43 are opened on the lower surface of both moving seats 42. One end of one L-shaped moving rod 41 is in contact with the middle of the arc groove 43. Two first rotating rods 46 are rotatably installed on both sides of the housing 31. A transmission wheel 47 is fixedly installed on one end of each of the four first rotating rods 46. A transmission belt 48 is installed between two adjacent transmission wheels 47. The other end of one L-shaped moving rod 41 is fixedly connected to one end of one transmission belt 48, and the other end of the other L-shaped moving rod 41 is fixedly connected to one end of the other transmission belt 48. A servo motor 49 is fixedly installed on one side of the housing 31. The drive output end of the servo motor 49 is fixedly connected to the other end of one of the first rotating rods 46.

[0072] By adopting the above technical solution, and by setting two L-shaped moving rods 41, two moving seats 42, and two arc-shaped grooves 43, when one L-shaped moving rod 41 contacts the middle of one arc-shaped groove 43, one L-shaped moving rod 41 causes the moving mold base 33 to move horizontally through the moving seat 42, and the other L-shaped moving rod 41 causes the moving mold base 33 to move horizontally in the opposite direction through the other moving seat 42, so that the moving mold base 33 can move horizontally back and forth. By turning on the servo motor 49, the drive shaft of the servo motor 49 causes a first rotating rod 46 to rotate. The first rotating rod 46 is transmitted through the transmission wheel 47 to the transmission belt 48, and the transmission belt 48 causes the L-shaped moving rod 41 to move horizontally.

[0073] The upper surface of the chassis 31 is provided with a guide groove 44, and a guide block 45 is slidably installed at one end of the guide groove 44. The lower surface of the moving mold base 33 is rotatably provided with the guide block 45.

[0074] By adopting the above technical solution, and by setting the guide groove 44 and the guide block 45, the guide block 45 can slide horizontally along the inner wall of the guide groove 44, while ensuring that the moving mold base 33 maintains horizontal movement.

[0075] A first transmission rod 51 is rotatably mounted on the side of the chassis 31 near the servo motor 49. A transmission gear 52 is fixedly mounted on the middle of one of the first rotating rods 46 and the middle of the first transmission rod 51. The two transmission gears 52 mesh with each other. A second transmission rod 53 is rotatably mounted on the upper surface of the chassis 31. A first synchronous pulley 54 is fixedly mounted on one end of the first transmission rod 51 and one end of the second transmission rod 53. A first synchronous belt 55 is driven between the two first synchronous pulleys 54. A second synchronous pulley 56 is fixedly mounted on the other end of the second transmission rod 53 and the other end of the other first rotating rod 46. A second synchronous belt 57 is driven between the two second synchronous pulleys 56.

[0076] By adopting the above technical solution, when one of the first rotating rods 46 rotates, the first rotating rod 46 causes the first transmission rod 51 to rotate in the opposite direction through two transmission gears 52. The first transmission rod 51 can cause the second transmission rod 53 to rotate in the same direction through two first synchronous pulleys 54 and a first synchronous belt 55. The second transmission rod 53 can cause the other first rotating rod 46 to rotate in the same direction through two second synchronous pulleys 56 and a second synchronous belt 57. As a result, the first rotating rods 46 on both sides of the housing 31 rotate synchronously in opposite directions, thereby causing the two transmission belts 48 to drive synchronously in opposite directions.

[0077] The flipping mechanism 6 includes a second rotating rod 61, which is rotatably connected to the upper surface of the housing 31. A positive magnet 62 is fixedly installed at one end of the second rotating rod 61. A connecting shaft 63 is rotatably installed on the upper surface of the guide block 45. A negative magnet 64 is fixedly installed at the end of the connecting shaft 63 away from the guide block 45. The positive magnet 62 and the negative magnet 64 are attracted to each other. A rotating shaft 65 is fixedly installed on the upper surface of the moving mold base 33. The end of the connecting shaft 63 away from the negative magnet 64 and the end of the rotating shaft 65 away from the moving mold base 33 are fixedly connected. A first bevel gear 67 is fixedly installed in the middle of the second transmission rod 53 and at the end of the second rotating rod 61 away from the positive magnet 62. The two first bevel gears 67 mesh with each other.

[0078] By adopting the above technical solution, when the moving mold base 33 separates from the fixed mold base 32, the negative magnet 64 contacts and attracts the positive magnet 62. The second transmission rod 53 causes the second rotating rod 61 to rotate through the two first bevel gears 67. The second rotating rod 61 causes the moving mold base 33 to rotate around the axis of the rotating shaft 65 through the positive magnet 62, the negative magnet 64, the connecting shaft 63 and the rotating shaft 65, so that the other side of the mold cavity of the moving mold base 33 faces the fixed mold base 32.

[0079] The cooling mechanism 8 includes side plates 81. Two side plates 81 are fixedly installed on the bottom wall of the transfer storage box 34. A rotating shaft 82 is rotatably installed between the two side plates 81. A connecting frame 83 is fixedly installed in the middle of the rotating shaft 82. A fan 84 is fixedly installed at one end of the connecting frame 83. Several ventilation slots 85 are evenly distributed on the surface of the guide plate 35. The fan 84 is located below the guide plate 35. A swing plate 86 is fixedly installed at one end of the rotating shaft 82.

[0080] By adopting the above technical solution, and by setting up a fan 84, the fan 84 can cool down the PVC drain pipe that falls on the guide plate 35, thereby achieving cooling of the PVC drain pipe. By driving the swing plate 86 to swing back and forth around the axis of the rotating shaft 82, the rotating shaft 82 rotates back and forth, and the rotating shaft 82 causes the fan 84 to swing back and forth around the axis of the rotating shaft 82 through the connecting frame 83, expanding the working range of the fan 84, thereby providing comprehensive cooling of the PVC drain pipe on the guide plate 35.

[0081] Inside the injection molding machine housing 1, a third rotating rod 87 is rotatably mounted. A crank 88 is fixedly mounted at one end of the third rotating rod 87, and a connecting rod 89 is fixedly mounted at one end of the crank 88. A strip groove 9 is provided on the swing plate 86. The end of the connecting rod 89 away from the crank 88 and the end of the strip groove 9 are in contact. A third transmission rod 91 is rotatably mounted on the side wall of the injection molding machine housing 1. A second bevel gear 92 is fixedly mounted at one end of the third transmission rod 91 and at the middle of the third rotating rod 87. The two second bevel gears 92 mesh with each other. A third synchronous pulley 93 is fixedly mounted at the other end of the first transmission rod 51 and the other end of the third transmission rod 91. A third synchronous belt 94 is installed between the two third synchronous pulleys 93.

[0082] By adopting the above technical solution, when the first transmission rod 51 rotates, the first transmission rod 51 can rotate the third transmission rod 91 through the two third synchronous pulleys 93 and the third synchronous belt 94. The third transmission rod 91 can rotate the third rotating rod 87 through the two second bevel gears 92. The third rotating rod 87 can cause the connecting rod 89 to reciprocate around the axis of the third rotating rod 87 through the crank 88. The connecting rod 89 causes the swing plate 86 to swing back and forth around the axis of the rotating shaft 82 through the strip groove 9.

[0083] Working principle: When the injection unit 2 injects the plasticized molten material into the space between the fixed mold base 32 and the moving mold base 33 of the injection molding unit 3 through the thrust of the screw, the molten material is formed between the fixed mold base 32 and the moving mold base 33. At the same time, the operator turns on the servo motor 49 and the fan 84. The drive shaft of the servo motor 49 causes the corresponding first rotating rod 46 to rotate. At this time, the first rotating rod 46 is transmitted through two adjacent transmission wheels 47 to a transmission belt 48. The transmission belt 48 causes the corresponding L-shaped moving rod 41 to move horizontally. During the rotation of the first rotating rod 46, the first transmission rod 51 is moved horizontally through two transmission gears 52. 1. Reverse rotation: The first transmission rod 51 causes the second transmission rod 53 to rotate in the same direction through two first synchronous pulleys 54 and a first synchronous belt 55. The second transmission rod 53 causes another first rotating rod 46 to rotate in the same direction through two second synchronous pulleys 56 and a second synchronous belt 57. At this time, another transmission belt 48 synchronously reverses the transmission. When the two transmission belts 48 synchronously reverse the transmission, the two L-shaped moving rods 41 move in the same direction. At this time, one L-shaped moving rod 41 causes the moving mold base 33 to move horizontally through the corresponding moving seat 42. The moving mold base 33 separates from the fixed mold base 32, and the PVC drainage pipe formed between the moving mold base 33 and the fixed mold base 32 falls onto the upper surface of the guide plate 35.

[0084] Simultaneously, the moving mold base 33 causes the guide block 45 to slide horizontally along the inner wall of the guide groove 44 via the rotating shaft 65. When the guide block 45 slides horizontally to the other end of the guide groove 44, the negative magnet 64 and the positive magnet 62 attract each other, one L-shaped moving rod 41 disengages from the corresponding arc-shaped groove 43, and the end of the other L-shaped moving rod 41 flips into the middle of another arc-shaped groove 43. During this process, the moving mold base 33 stops moving horizontally. As the second transmission rod 53 rotates, the second transmission rod 53 causes the second rotating rod 61 to rotate via two first bevel gears 67. The second rotating rod 61 then... Positive magnet 62, negative magnet 64, connecting shaft 63 and rotating shaft 65 cause the moving mold base 33 to rotate around the axis of rotating shaft 65, so that the other side of the mold cavity of the moving mold base 33 faces the side of the fixed mold base 32. At this time, as another L-shaped moving rod 41 enters the middle of the corresponding arc groove 43, the moving mold base 33 moves horizontally towards the side of the fixed mold base 32 through the corresponding moving seat 42, and the moving mold base 33 fits against the side of the fixed mold base 32, thus conveniently realizing automatic mold changing in the injection molding process of PVC drainage pipe, thereby effectively improving the production efficiency of PVC drainage pipe.

[0085] Meanwhile, the first transmission rod 51 rotates the third transmission rod 91 through two third synchronous pulleys 93 and a third synchronous belt 94. The third transmission rod 91 rotates the third rotating rod 87 through two second bevel gears 92. The third rotating rod 87 causes the connecting rod 89 to reciprocate around the axis of the third rotating rod 87 through the crank 88. The connecting rod 89 causes the swing plate 86 to reciprocate around the axis of the rotating shaft 82 through the strip groove 9. The rotating shaft 82 causes the fan 84 to reciprocate around the axis of the rotating shaft 82 through the connecting frame 83, thus expanding the working range of the fan 84. During the reciprocating swing, the fan 84 provides comprehensive cooling to the PVC drain pipe on the guide plate 35, thereby facilitating the initial cooling of the injection-molded PVC drain pipe and effectively improving the cooling efficiency of the PVC drain pipe. At the same time, it prevents subsequent operators from being burned by contact with the PVC drain pipe during operation.

[0086] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A short-cycle injection molding method for PVC drainage pipes, characterized in that, Includes the following steps: S1. Raw material preparation PVC resin granules, plasticizer, stabilizer, lubricant and filler are added to the hopper of the injection molding equipment in proportion, and the raw materials in the hopper are mixed. S2, Mold Preparation Select a matching mold based on the shape and outer pipe size of the PVC drainage pipe, and install the mold on the mold locking device of the injection molding equipment; S3, Raw material melting The mixed raw materials are fed into the screw of the injection molding equipment, where they are melted by the rotation and heating of the screw. S4, Injection Molding Molten raw materials are injected into the cavity of a mold through the injection device of an injection molding machine, and then cooled and solidified to obtain PVC drainage pipes; S5, Demolding After the PVC drainage pipe is injection molded, the mold is opened, the cooled and cured PVC drainage pipe is taken out, and then cooled, cleaned and trimmed. S6, Inspection Perform visual and dimensional inspections on injection-molded PVC drainage pipes to ensure that product quality meets production requirements; S7, Packaging Qualified PVC drainage pipes are bagged and packaged. The injection molding equipment includes an injection molding machine housing (1), an injection unit (2), and an injection molding unit (3). The injection unit (2) and the injection molding unit (3) are installed on the upper surface of the injection molding machine housing (1). The injection molding unit (3) includes a housing (31), which is fixedly installed on the upper surface of the injection molding machine housing (1). A fixed mold base (32) is fixedly installed on the side wall of the housing (31). A mold cavity is provided on one side of the fixed mold base (32). A movable mold base (33) is slidably provided on the side wall of the housing (31). Mold cavities are provided on both sides of the movable mold base (33). The moving mold base (33) is in contact with one side of the fixed mold base (32). A transfer storage box (34) is fixedly installed at the bottom of the chassis (31). A number of heat dissipation slots (341) are evenly distributed on both sides of the transfer storage box (34). A guide plate (35) is fixedly installed on the side wall of the transfer storage box (34). The guide plate (35) is inclined. A discharge hopper (36) is fixedly installed on one side of the transfer storage box (34). A mold changing mechanism (4) and a flipping mechanism (6) are respectively provided on the chassis (31). A cooling mechanism (8) is provided inside the transfer storage box (34). The mold changing mechanism (4) includes two L-shaped moving rods (41). Moving seats (42) are fixedly installed on both sides of the moving mold base (33). Arc grooves (43) are opened on the lower surface of the two moving seats (42). One end of one of the L-shaped moving rods (41) is in contact with the middle of the arc groove (43). Two first rotating rods (46) are rotatably installed on both sides of the housing (31). One end of each of the four first rotating rods (46) is fixedly installed with a transmission wheel (47). A transmission belt (48) is installed between two adjacent transmission wheels (47). The other end of one of the L-shaped moving rods (41) is fixedly connected to one end of one of the transmission belts (48). The other end of the other L-shaped moving rod (41) is fixedly connected to one end of the other transmission belt (48). A servo motor (49) is fixedly installed on one side of the housing (31). The drive output end of the servo motor (49) is fixedly connected to the other end of one of the first rotating rods (46). The upper surface of the chassis (31) is provided with a guide groove (44), and a guide block (45) is slidably installed at one end of the guide groove (44). The lower surface of the guide block (45) is rotatably provided on the moving mold base (33). A first transmission rod (51) is rotatably mounted on the side of the chassis (31) near the servo motor (49). A transmission gear (52) is fixedly mounted on the middle of one of the first rotating rods (46) and the middle of the first transmission rod (51). The two transmission gears (52) mesh with each other. A second transmission rod (53) is rotatably mounted on the upper surface of the chassis (31). A first synchronous pulley (54) is fixedly mounted on one end of the first transmission rod (51) and one end of the second transmission rod (53). A first synchronous belt (55) is driven between the two first synchronous pulleys (54). A second synchronous pulley (56) is fixedly mounted on the other end of the second transmission rod (53) and the other end of the other first rotating rod (46). A second synchronous belt (57) is driven between the two second synchronous pulleys (56). The flipping mechanism (6) includes a second rotating rod (61), which is rotatably connected to the upper surface of the housing (31). A positive magnet (62) is fixedly installed at one end of the second rotating rod (61). A connecting shaft (63) is rotatably installed on the upper surface of the guide block (45). A negative magnet (64) is fixedly installed at the end of the connecting shaft (63) away from the guide block (45). The positive magnet (62) and the negative magnet (64) are attracted to each other. A rotating shaft (65) is fixedly installed on the upper surface of the moving mold base (33). The end of the connecting shaft (63) away from the negative magnet (64) and the end of the rotating shaft (65) away from the moving mold base (33) are fixedly connected. A first bevel gear (67) is fixedly installed in the middle of the second transmission rod (53) and at the end of the second rotating rod (61) away from the positive magnet (62). The two first bevel gears (67) mesh with each other.

2. The short-cycle injection molding method for PVC drainage pipes as described in claim 1, characterized in that, The PVC resin granules are polyvinyl chloride resin.

3. The short-cycle injection molding method for PVC drainage pipes as described in claim 1, characterized in that, The screw filling control time of the injection molding equipment is 1.4s, the temperature of the mold is 25℃, and the temperature of the molten raw material is 205℃.

4. The short-cycle injection molding method for PVC drainage pipes as described in claim 1, characterized in that, The cooling mechanism (8) includes side plates (81), two side plates (81) are fixedly installed on the bottom wall of the transfer storage box (34), a rotating shaft (82) is rotatably installed between the two side plates (81), a connecting frame (83) is fixedly installed in the middle of the rotating shaft (82), a fan (84) is fixedly installed at one end of the connecting frame (83), a number of evenly distributed ventilation slots (85) are opened on the surface of the guide plate (35), the fan (84) is located below the guide plate (35), and a swing plate (86) is fixedly installed at one end of the rotating shaft (82).

5. The short-cycle injection molding method for PVC drainage pipes as described in claim 4, characterized in that, The injection molding machine housing (1) is rotatably mounted with a third rotating rod (87). A crank (88) is fixedly mounted at one end of the third rotating rod (87). A connecting rod (89) is fixedly mounted at one end of the crank (88). A strip groove (9) is provided on the swing plate (86). The end of the connecting rod (89) away from the crank (88) and the end of the strip groove (9) are in contact with each other. A third transmission rod (91) is rotatably mounted on the side wall of the injection molding machine housing (1). A second bevel gear (92) is fixedly mounted at one end of the third transmission rod (91) and at the middle of the third rotating rod (87). The two second bevel gears (92) mesh with each other. A third synchronous pulley (93) is fixedly mounted at the other end of the first transmission rod (51) and the other end of the third transmission rod (91). A third synchronous belt (94) is installed between the two third synchronous pulleys (93).

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