Injection molding machine and injection molding method for integrally forming PVC-C large pipe fitting

Abstract

The invention provides an injection molding machine and an injection molding method for integrally molding a PVC-C large pipe fitting, and belongs to the technical field of injection molding of large pipe fittings. Comprising an injection molding device and a material melting device, the material melting device can melt injection molding plastic, the injection molding device is communicated with the material melting device, the material melting device can inject the molten injection molding plastic into the injection molding device, the injection molding device can introduce injection molding molten materials into a mold, the injection molding device comprises a connection and disconnection assembly, and the connection and disconnection assembly further comprises a connection and disconnection assembly. And the blocking rod is positioned in the connection and disconnection assembly. By arranging the connection and disconnection assembly, the conical plugging pipe and the conical runner form first-stage buffer fit, at the last stage of injection molding, the melt flow is firstly reduced, the flow speed is buffered, then second-stage thorough plugging is conducted through the plugging rod, runner accumulation caused by direct cutoff of the melt is avoided, and a pressure buffer structure of the pushed cover and the spring is matched, so that pipeline bursting can be effectively prevented; the defect of single needle valve type partition is thoroughly overcome, and the problems that existing injection molding equipment is high in production cost and long in working time are solved.

Description

Technical Field

[0001] This invention relates to the field of injection molding technology for large pipe fittings, and particularly to an injection molding machine and injection molding method for one-piece molding of large PVC-C pipe fittings. Background Technology

[0002] Chlorinated polyvinyl chloride (PVC-C) large pipe fittings are widely used in municipal water supply and drainage, industrial fluid transportation, chemical pipelines and other fields due to their excellent high temperature resistance, corrosion resistance and pressure resistance. Their molding quality directly affects the sealing performance and service life of the pipeline system.

[0003] After injection molding of large pipe fittings, the injection port needs to be isolated to avoid stringing, drooling, or residue at the gate. Existing equipment mostly uses a single needle valve isolation, but the flow rate of the injection molten material is directly cut off without buffering, which can easily cause the molten material to accumulate in the runner, causing it to burst the pipe and increasing production costs and time. At the same time, the molten material accumulated in the runner will change the filling speed and pressure distribution in the runner. During the second injection, it will cause uneven injection speed, resulting in defects such as wall thickness deviation, internal shrinkage cavities, and stress concentration in the product, affecting the quality of the injection molded parts.

[0004] Therefore, this application provides an injection molding machine and injection molding method for integral molding of large PVC-C pipe fittings to meet the needs. Summary of the Invention

[0005] The technical problem to be solved by this invention is to provide an injection molding machine and injection method for one-piece molding of large PVC-C pipe fittings. By setting up a disconnection component, the conical plug and the conical flow channel form a primary buffer cooperation. At the end of the injection, the flow rate of the melt is reduced and the flow velocity is buffered. Then, the plug rod completely seals the flow channel in a secondary stage, avoiding the accumulation of the flow channel caused by direct cutting of the melt. Combined with the pressure buffer structure of the push cap and spring, it can effectively prevent the pipe from bursting. It completely avoids the drawbacks of the single needle valve isolation, thus solving the problems of high production cost and long processing time of existing injection molding equipment.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: An injection molding machine for integral molding of large PVC-C pipe fittings includes an injection molding device and a melting device. The melting device can melt the injection molding plastic. The injection molding device is connected to the melting device, and the melting device can inject the melted injection molding plastic into the injection molding device. The injection molding device can pass the injection molding molten material into the mold. The injection molding device includes a disconnection component and a plug rod located in the disconnection component. The disconnection assembly includes a three-pronged tube with a tapered flow channel on its inner wall in the middle. A tapered plug is slidably connected to the top inner wall of the three-pronged tube. The bottom outer wall of the tapered plug is used in conjunction with the tapered flow channel, and there is a gap after the conjunction. The plug rod is slidably connected to the inner wall of the tapered plug. The bottom outer wall of the three-pronged tube has an external thread. An internally threaded tube is installed at the bottom of the three-pronged tube, and the internally threaded tube is used in conjunction with the external thread. The bottom of the plug rod is engaged with the bottom opening of the internally threaded tube.

[0007] Optionally, protective seats are fixedly installed on both sides of the top of the three-pronged tube, and the two sets of protective seats are fixedly connected by bolts. Insulation shells are fixedly installed on both sides of the top of the internally threaded tube, and the top of the insulation shell is inserted into the inner wall of the corresponding protective seat. A wound electric heating tube is fixedly installed on the inner wall of the insulation shell.

[0008] Optionally, a cover is fixedly installed on the top of the protective seat, and the bottom of the cover is located inside the right side opening of the three-way pipe. A telescopic rod is fixedly installed on the bottom of the cover, and a push-receiving cover is fixedly installed on the bottom of the telescopic rod. The push-receiving cover is slidably and sealingly connected to the inner wall of the right side opening of the three-way pipe. A spring is fixedly installed on the top of the push-receiving cover, the telescopic rod is located inside the spring, and the other end of the spring is fixedly connected to the bottom of the cover.

[0009] Optionally, an air chamber is fixedly installed on the outer wall of the protective seat. A piston rod is slidably connected to the inner wall of the air chamber, and the piston rod slidably passes through the top of the air chamber. Air guide holes are provided on the top and bottom side walls of the air chamber, and the piston rod is located between the two sets of air guide holes. A connecting arm is rotatably connected to the top of the piston rod. A push tube is fixedly installed on the top of the conical plug tube. A groove is provided on the bottom outer wall of the push tube. The other ends of the two sets of connecting arms are engaged with the groove, and the end walls of the two sets of connecting arms are fixedly connected by bolts. The plug rod is slidably connected to the inner wall of the push tube.

[0010] Optionally, the protective seat has slots on both sides of its top, and the two sets of protective seats are equipped with the same top seat. The top seat has locking blocks at its four bottom corners, and the locking blocks engage with the corresponding slots. A material passage pipe is fixedly installed on the inner left side of the top seat, and the material passage pipe is sealed and connected to the left side opening of the three-way pipe. A disc opening is opened on the top of the top seat, and the push pipe passes through the middle of the top seat. Limiting discs are fixedly installed on the top and bottom outer walls of the push pipe. The limiting disc at the top is in movable contact with the disc opening, and the limiting disc at the bottom is in movable contact with the top of the protective seat. A top frame is fixedly installed on the top of the top seat, and a cylinder is fixedly installed on the inner wall of the top of the top frame, and the output end of the cylinder is fixedly connected to the top of the plug rod.

[0011] Optionally, the melting device includes a support shell, a metering zone is formed on the inner wall of the front end of the support shell, a piston rod is slidably connected to the inner wall of the metering zone, a cylinder is fixedly installed on the end wall of the support shell, and the output end of the cylinder is fixedly connected to the end wall of the piston rod. A feeding channel is formed on the front wall of the support shell, one end of the feeding channel is connected to the inside of the metering zone, and the other end is sealed to the material passage pipe.

[0012] Optionally, a sealing shell is fixedly installed on the top of the support shell, and a hot-melt spiral feed rod is rotatably connected to the inner wall of the sealing shell. A rod storage groove is opened on the inner wall of the middle part of the hot-melt spiral feed rod, and an anti-backflow rod is inserted into the inner wall of the rod storage groove. A cylinder is fixedly installed on the outer wall of the sealing shell, and the output end of the cylinder is fixedly connected to the end wall of the anti-backflow rod. A material conveying channel is opened on the front wall of the sealing shell, and the front end of the anti-backflow rod can engage with the inner wall of the material conveying channel. The bottom of the material conveying channel communicates with the inside of the metering area. A worm gear is fixedly installed on the end wall of the hot-melt spiral feed rod, and a worm is rotatably connected to the inner wall of the sealing shell, and the worm meshes with the worm gear. A motor is fixedly installed on the top of the sealing shell, and the output end of the motor is fixedly connected to the top of the worm. A material injection port is opened on the top of the sealing shell, and the material injection port communicates with the hot-melt spiral feed rod.

[0013] Optionally, an injection molding method for integrally molding large PVC-C pipe fittings further includes the following specific operating steps: S1: Solid plastic raw material is injected into the sealing shell and the hot-melt spiral feed rod through the injection port. Then, the drive motor drives the worm gear to work, making the hot-melt spiral feed rod rotate and conveying the solid raw material forward. During the conveying process, the raw material is melted and injected into the metering zone through the conveying channel. The molten raw material pushes the piston rod two backward, and the volume of raw material in the metering zone is calculated based on the displacement of the piston rod two. S2: When the injection molding machine is working, stop injecting raw material into the injection port, and at the same time drive cylinder three to push the anti-backflow rod outward, so that the anti-backflow rod blocks the material conveying channel. At the same time, drive cylinder two to push piston rod two outward, so that the molten raw material in the metering zone is injected into the left port of the three-way pipe through the feeding channel and the material passage pipe. S3: The raw material in the left port of the three-way pipe can flow into the internal threaded pipe through the conical flow channel, and finally flow into the mold through the bottom port of the internal threaded pipe, thus forming injection molding. During the injection molding process, according to the required volume of molten material in the mold, when the injection molding is about to be completed, compressed air is injected into the air guide hole at the top of the air chamber, which causes the compressed air to squeeze the piston rod one downward, causing the piston rod one to drive the connecting arm downward, forcing the two sets of connecting arms to press the push tube downward, causing the push tube to drive the conical plug tube to move downward, forcing the conical plug tube to cooperate with the conical flow channel, thereby reducing the amount of molten raw material flowing into the internal threaded pipe; S4: After the conical plug and the conical flow channel are engaged, the material injection in the metering zone is stopped. When the injection molding is completed, the output axis of the drive cylinder is pushed outward to force the plug rod to block the bottom opening of the internal thread tube, thereby stopping the supply of material to the mold and completing the injection molding.

[0014] Compared with the prior art, the present invention has at least the following beneficial effects:

[0015] In the above solution, by setting up a disconnection component, the conical plug and the conical flow channel form a primary buffering mechanism. At the end of the injection molding process, the melt flow rate is reduced and the flow velocity is buffered. Then, the plug rod completely seals the flow channel in a secondary stage, avoiding the accumulation of the flow channel caused by direct cutting of the melt. Combined with the pressure buffer structure of the push cap and spring, it can effectively prevent the pipeline from bursting. It completely avoids the drawbacks of a single needle valve type isolation. At the same time, the two-stage isolation design has no abrupt cutting action, which can eliminate the generation of stringing, drooling and residue at the gate. There is no need for subsequent grinding and trimming processes, reducing labor time and processing costs. It also avoids the phenomena of dripping and back suction, improving the integrity of the product appearance.

[0016] By setting up a melting device and utilizing the integrated conveying and melting design of the hot melt spiral feed rod, combined with the volume metering function of the metering zone, precise raw material supply can be achieved. The orderly coordination of the two-stage partitions can quickly cut off the material when the injection molding is completed, avoiding material waste and improving the utilization rate of raw materials. Attached Figure Description

[0017] The accompanying drawings, which are incorporated herein and form part of the specification, illustrate embodiments of the invention and, together with the specification, further serve to explain the principles of the invention and enable those skilled in the art to practice and use the invention.

[0018] Figure 1 A three-dimensional structural diagram of an injection molding machine for one-piece molding of large PVC-C pipe fittings; Figure 2 This is a schematic diagram of the assembly of the injection molding unit and the melting unit; Figure 3 This is a schematic diagram of the melting device; Figure 4 This is a schematic diagram of the drive structure of the hot-melt spiral feed rod; Figure 5 This is a schematic diagram of the installation of the anti-backflow rod inside the hot-melt spiral feed rod; Figure 6 This is a schematic diagram of the injection molding unit. Figure 7 This is a schematic diagram of the assembly of the top seat and the top frame; Figure 8 This is a schematic diagram of the assembly of the top seat and the two sets of protective seats; Figure 9 A bottom view of the assembly of the top seat and the two sets of protective seats; Figure 10 This is a schematic diagram of the installation of the material passage pipe inside the top seat; Figure 11 This is a schematic diagram of the air chamber being assembled on the protective base. Figure 12 This is a schematic diagram showing the connection between piston rod 1 and connecting arm; Figure 13 This is a schematic diagram of the internal structure of the air chamber; Figure 14 This is a schematic diagram of the assembly of two sets of protective seats; Figure 15 This is a schematic diagram of the assembly of two sets of insulation shells; Figure 16 A top assembly cross-sectional view of the injection molding unit; Figure 17 This is a schematic diagram of the connection / disconnection assembly; Figure 18 This is a schematic diagram of the assembly of the tapered plug inside the three-way pipe; Figure 19 This is a schematic diagram of the assembly of the inner plug rod of the tapered plug tube; Figure 20 This is a schematic diagram of the assembly of two sets of connecting arms and slots; Figure 21 This is a schematic diagram showing the fit between the conical plug and the conical flow channel; Figure 22 This is a schematic diagram showing the fit between the plug rod and the internally threaded pipe after the tapered plug and the tapered flow channel are fitted together; Figure 23 An assembly diagram of the various components covering the top; Figure 24 This is a breakdown diagram of the various components.

[0019] Figure label: Injection molding device 100, connecting assembly 110, three-way pipe 111, tapered flow channel 112, external thread 113, internal thread pipe 114, tapered plug 115, push pipe 116, slot 117, limiting plate 118, plug rod 120, protective seat 130, bayonet 131, insulation shell 132, heating element 133, cover 134, telescopic rod 135, push cover 136, spring 137, air chamber 140, piston rod 141, air guide hole 142, connecting arm 14 3. Top seat 150, feed pipe 151, clamping block 152, disc 153, top frame 160, cylinder one 161, melting device 200, support shell 210, metering area 211, piston rod two 212, cylinder two 213, feeding channel 214, sealing shell 220, hot melt spiral feed rod 221, rod storage groove 222, anti-backflow rod 223, cylinder three 224, worm gear 225, worm 226, motor 227, injection port 228, conveying channel 229.

[0020] As shown in the figure, specific structures and devices are marked in the figure to clearly illustrate the structure of the embodiments of the present invention. However, this is only for illustrative purposes and is not intended to limit the present invention to this specific structure, device and environment. Those skilled in the art can adjust or modify these devices and environments according to specific needs. Detailed Implementation

[0021] The following is a detailed description of an injection molding machine and injection method for integral molding of large PVC-C pipe fittings provided by the present invention, with reference to the accompanying drawings and specific embodiments. It should be noted that, to make the embodiments more detailed, the following embodiments are the best and preferred embodiments; those skilled in the art can also use other alternative methods to implement some known technologies; and the accompanying drawings are only for more specific description of the embodiments and are not intended to specifically limit the present invention.

[0022] like Figures 1 to 24As shown, an embodiment of the present invention provides an injection molding machine and injection molding method for integral molding of large PVC-C pipe fittings, including an injection molding device 100 and a melting device 200. The melting device 200 can melt the injection plastic. The injection molding device 100 and the melting device 200 are connected, and the melting device 200 can inject the melted injection plastic into the injection molding device 100. The injection molding device 100 can pass the injection molten material into the mold. The injection molding device 100 includes a disconnection assembly 110, and further includes a component located at the disconnection assembly 110. The plug rod 120 is located inside the 0 section; the disconnecting assembly 110 includes a three-way pipe 111, with a tapered flow channel 112 formed on the inner wall of the middle section of the three-way pipe 111. A tapered plug 115 is slidably connected to the top inner wall of the three-way pipe 111. The bottom outer wall of the tapered plug 115 is used in conjunction with the tapered flow channel 112, and there is a gap after the conjunction. When the tapered plug 115 and the tapered flow channel 112 are in conjunction, the volume of raw material flowing into the internally threaded pipe 114 can be reduced. The plug rod 120 is slidably connected to the inner wall of the tapered plug 115. The three-way pipe 111... The bottom outer tube wall is provided with an external thread 113, and the bottom of the three-way tube 111 is equipped with an internal thread tube 114, which is used in conjunction with the external thread 113. The bottom of the plug rod 120 is engaged with the bottom opening of the internal thread tube 114. In this invention, when the injection molding is about to be completed, compressed air is injected into the air guide hole 142 at the top of the air chamber 140, which causes the compressed air to squeeze the piston rod 141 downward, causing the piston rod 141 to drive the connecting arm 143 downward, forcing the two sets of connecting arms 143 to press the push tube 11 downward. 6. This causes the push tube 116 to move the conical plug tube 115 downward, forcing the conical plug tube 115 to engage with the conical flow channel 112, thereby reducing the amount of molten material flowing into the internal threaded tube 114. After the conical plug tube 115 engages with the conical flow channel 112, the material injection in the metering zone 211 is stopped. When the injection molding is completed, the output axis of the drive cylinder 161 is pushed outward to push the plug rod 120, forcing the plug rod 120 to block the bottom opening of the internal threaded tube 114, thereby stopping the supply of material to the mold and completing the injection molding.

[0023] In this embodiment, as Figures 14 to 16 As shown, protective seats 130 are fixedly installed on both sides of the top of the three-way tube 111, and the two sets of protective seats 130 are fixedly connected by bolts. Insulation shells 132 are fixedly installed on both sides of the top of the internal threaded tube 114, and the top of the insulation shell 132 is inserted into the inner wall of the corresponding protective seat 130. A wound electric heating tube 133 is fixedly installed on the inner wall of the insulation shell 132. By energizing the electric heating tube 133, the insulation shell 132 is heated, which can achieve the function of heat preservation of the molten plastic in the three-way tube 111 and prevent it from cooling and solidifying.

[0024] In this embodiment, as Figures 21 to 24As shown, a cover 134 is fixedly installed on the top of the protective seat 130, and the bottom of the cover 134 is located inside the right side opening of the three-way pipe 111. A telescopic rod 135 is fixedly installed on the bottom of the cover 134, and a push-receiving cover 136 is fixedly installed on the bottom of the telescopic rod 135. The push-receiving cover 136 is slidably connected to the inner wall of the right side opening of the three-way pipe 111. A spring 137 is fixedly installed on the top of the push-receiving cover 136, and the telescopic rod 135 is located inside the spring 137. The other side of the spring 137... The end is fixedly connected to the bottom of the cover 134. In this invention, after the conical plug 115 and the conical flow channel 112 are engaged, before the raw material injection in the metering area 211 stops, a small amount of molten material will accumulate in the three-way tube 111. At this time, the molten material in the three-way tube 111 can push the push cover 136 upward, causing the telescopic rod 135 to contract and the spring 137 to be compressed, thereby relieving the accumulation force generated by the molten material in the three-way tube 111 and preventing the three-way tube 111 from bursting.

[0025] As one implementation method in this embodiment, such as Figures 11 to 13As shown, an air chamber 140 is fixedly installed on the outer wall of the protective seat 130. A piston rod 141 is slidably connected to the inner wall of the air chamber 140, and the piston rod 141 passes through the top of the air chamber 140. Air guide holes 142 are provided on both the top and bottom side walls of the air chamber 140, and the piston rod 141 is located between the two sets of air guide holes 142. By injecting high-pressure gas into different air guide holes 142, the piston rod 141 can be displaced, thereby driving the connecting arm 143 to move. A connecting arm 143 is rotatably connected to the top of a conical plug 115, and a push tube 116 is fixedly installed on the top of the push tube 116. A groove 117 is opened on the outer wall of the bottom of the push tube 116. The other ends of the two sets of connecting arms 143 are engaged with the groove 117, and the end walls of the two sets of connecting arms 143 are fixedly connected by bolts. The plug rod 120 is slidably connected to the inner wall of the push tube 116. In this invention, during the injection molding process, according to the required volume of melt material for the mold, when the injection molding is about to be completed, the melt material is introduced into the air guide hole 142 at the top of the air chamber 140. Injecting compressed air forces the piston rod 141 downwards, causing it to drive the connecting arms 143 downwards. This forces the two sets of connecting arms 143 to press down on the push tube 116, causing the push tube 116 to move the tapered plug 115 downwards. This forces the tapered plug 115 to engage with the tapered flow channel 112, thereby reducing the amount of molten material flowing into the internally threaded tube 114. Specifically, during the injection molding process, the injection of molding material needs to be stopped quickly and abruptly interrupted after injection molding is completed. This not only reduces raw material loss but also effectively prevents residues, stringing, or drooling at the gate. It eliminates the need for additional grinding and trimming and completely removes flow and back suction. Existing isolation methods mostly use injection needle valves for isolation, but since the flow rate of the melt remains unchanged before isolation, abruptly isolating the melt will cause it to accumulate in the injection tube, which may damage the injection tube. At the same time, during secondary injection, the injection speed will be changed, thereby changing the stress in the injection part and affecting the quality of the injection part.

[0026] In this embodiment, as Figures 6 to 11As shown, the protective seat 130 has slots 131 on both sides of its top. Both sets of protective seats 130 are fitted with the same top seat 150. Each of the four corners of the bottom of the top seat 150 has a locking block 152, which engages with the corresponding slot 131. The top seat 150 is engaged with the two sets of protective seats 130 through the engagement of the locking blocks 152 and slots 131. A feed pipe 151 is fixedly installed on the inner left side of the top seat 150, and the feed pipe 151 is sealed and connected to the left opening of the three-way pipe 111. The molten material in the feed pipe 151 can enter the three-way pipe 111. A disc opening 153 is located at the top of the top seat 150, and a push pipe 116 penetrates the middle of the top seat 150. Limiting discs 118 are fixedly installed on the top and bottom outer walls. The limiting disc 118 at the top is in contact with the opening 153. The opening 153 can limit the movement of the push tube 116. When the limiting disc 118 on the push tube 116 moves to contact the opening 153, the conical plug tube 115 just matches the conical flow channel 112. The limiting disc 118 at the bottom is in contact with the top of the protective seat 130. Similarly, the top of the protective seat 130 limits the movement of the limiting disc 118 at the bottom. A top frame 160 is fixedly installed on the top of the top seat 150. A cylinder 161 is fixedly installed on the inner wall of the top of the top frame 160, and the output end of the cylinder 161 is fixedly connected to the top of the plug rod 120.

[0027] As one implementation method in this embodiment, such as Figure 2 and Figure 3 As shown, the melting device 200 includes a support shell 210. A metering zone 211 is formed on the inner wall of the front end of the support shell 210. A piston rod 212 is slidably connected to the inner wall of the metering zone 211. A cylinder 213 is fixedly installed on the end wall of the support shell 210, and the output end of the cylinder 213 is fixedly connected to the end wall of the piston rod 212. A feeding channel 214 is formed on the front wall of the support shell 210. One end of the feeding channel 214 communicates with the interior of the metering zone 211, and the other end is sealed to the material passage pipe 151. In this invention, when the injection molding machine is working, the injection into the injection port 228 is stopped. The raw material is simultaneously driven by cylinder 224 to push the anti-backflow rod 223 outward, blocking the material conveying channel 229. At the same time, cylinder 213 is driven to push the piston rod 212 outward, thereby injecting the molten raw material in the metering zone 211 into the left port of the three-way pipe 111 through the feeding channel 214 and the material passage pipe 151. In particular, the metering zone 211 is designed as a straight cylinder with a known diameter. By calculating the displacement of the piston rod 212, the volume of the raw material in the metering zone 211 can be calculated, thus facilitating the control of the volume of raw material input into the mold.

[0028] In this embodiment, as Figures 2 to 5As shown, a sealing shell 220 is fixedly installed on the top of the support shell 210, and the support shell 210 supports the sealing shell 220. A hot-melt spiral feed rod 221 is rotatably connected to the inner wall of the sealing shell 220. The hot-melt spiral feed rod 221 can transport solid plastic and heat it during the transport process to make it molten. A rod storage groove 222 is opened on the inner wall of the middle part of the hot-melt spiral feed rod 221, and an anti-backflow rod 223 is inserted into the inner wall of the rod storage groove 222. The sealing shell 210... A cylinder 224 is fixedly installed on the outer wall of the sealing shell 220, and the output end of the cylinder 224 is fixedly connected to the end wall of the anti-backflow rod 223. A material conveying channel 229 is opened on the front wall of the sealing shell 220, and the front end of the anti-backflow rod 223 can engage with the inner wall of the material conveying channel 229. During the feeding process in the metering zone 211, the front end of the anti-backflow rod 223 is driven to block the material conveying channel 229, which can prevent the raw material from flowing back into the sealing shell 220. The bottom of the material conveying channel 229 is connected to the inside of the metering zone 211. A worm gear 225 is fixedly installed on the end wall of the spiral feed rod 221. A worm 226 is rotatably connected to the inner wall of the sealing shell 220, and the worm 226 meshes with the worm gear 225. A motor 227 is fixedly installed on the top of the sealing shell 220, and the output end of the motor 227 is fixedly connected to the top of the worm 226. A filling port 228 is opened on the top of the sealing shell 220, and the filling port 228 communicates with the hot-melt spiral feed rod 221. In this invention, the filling port 228 supplies material to the sealing shell 220 and the hot-melt spiral feed rod 221. Solid plastic raw material is injected into the spiral feed rod 221. Then, the drive motor 227 drives the worm gear 225 and worm 226 to work, causing the hot melt spiral feed rod 221 to rotate and convey the solid raw material forward. During the conveying process, the raw material is melted and injected into the metering zone 211 through the conveying channel 229. This causes the molten raw material to push the piston rod 212 backward, and the volume of raw material in the metering zone 211 is calculated based on the displacement of the piston rod 212.

[0029] The working method of the technical solution provided by the present invention is as follows: S1: Solid plastic raw material is injected into the sealing shell 220 and the hot melt spiral feed rod 221 through the injection port 228. Then, the drive motor 227 drives the worm gear 225 and worm 226 to work, so that the hot melt spiral feed rod 221 rotates and conveys the solid raw material forward. During the conveying process, the raw material is melted and injected into the metering zone 211 through the conveying channel 229. The molten raw material pushes the piston rod 212 backward and the volume of raw material in the metering zone 211 is calculated based on the displacement of the piston rod 212. S2: When the injection molding machine is working, stop injecting raw material into the injection port 228, and at the same time drive cylinder three 224 to push the anti-backflow rod 223 outward, so that the anti-backflow rod 223 blocks the material conveying channel 229. At the same time, drive cylinder two 213 to push piston rod two 212 outward, so that the molten raw material in the metering zone 211 is injected into the left port of the three-way pipe 111 through the feeding channel 214 and the material passage pipe 151. S3: The raw material in the left port of the three-way pipe 111 can flow into the internal threaded pipe 114 through the tapered flow channel 112, and finally flow into the mold through the bottom port of the internal threaded pipe 114, thus forming injection molding. During the injection molding process, according to the required volume of molten material in the mold, when the injection molding is about to be completed, compressed air is injected into the air guide hole 142 at the top of the air chamber 140, so that the compressed air squeezes the piston rod 141 downward, causing the piston rod 141 to drive the connecting arm 143 downward, forcing the two sets of connecting arms 143 to press the push tube 116 downward, causing the push tube 116 to drive the tapered plug 115 to move downward, forcing the tapered plug 115 to cooperate with the tapered flow channel 112, thereby reducing the amount of molten raw material flowing into the internal threaded pipe 114; S4: After the tapered plug 115 and tapered flow channel 112 are engaged, the material injection in the metering area 211 is stopped. When the injection molding is completed, the output axis of the drive cylinder 161 is pushed outward to push the plug rod 120, forcing the plug rod 120 to block the bottom opening of the internal thread tube 114, thereby stopping the supply of material to the mold and completing the injection molding.

[0030] This invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of this invention. To provide the public with a thorough understanding of this invention, specific details are described in detail in the following preferred embodiments; however, those skilled in the art will fully understand the invention even without these details. Furthermore, to avoid unnecessary misunderstanding of the essence of this invention, well-known methods, processes, procedures, components, and circuits are not described in detail.

[0031] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A PVC-C large pipe fitting integrally formed injection molding machine, comprising an injection molding device (100) and a melting device (200), the melting device (200) can melt the injection plastic, the injection molding device (100) and the melting device (200) are communicated, and the melting device (200) can inject the melted injection plastic into the injection molding device (100), and the injection molding device (100) can pass the injection melt into a mold, characterized in that, The injection molding device (100) comprises a shut-off assembly (110), further comprises a plug rod (120) in the shut-off assembly (110); The shut-off assembly (110) comprises a three-prong pipe (111), a tapered flow channel (112) is arranged in the inner wall of the middle part of the three-prong pipe (111), a tapered plug pipe (115) is sealingly and slidably connected to the top inner wall of the three-prong pipe (111), the bottom outer wall of the tapered plug pipe (115) is used in cooperation with the tapered flow channel (112), and a gap is formed after cooperation, the plug rod (120) is slidably connected to the inner wall of the tapered plug pipe (115), an external thread (113) is arranged on the outer pipe wall of the bottom of the three-prong pipe (111), an internal thread pipe (114) is arranged on the bottom of the three-prong pipe (111), and the internal thread pipe (114) is used in cooperation with the external thread (113), and the bottom of the plug rod (120) is clamped with the bottom pipe opening of the internal thread pipe (114).

2. The PVC-C large pipe fitting integrated molding injection molding machine according to claim 1, characterized in that, The top of the three-prong pipe (111) is fixedly provided with a protection seat (130) on both sides, and the two protection seats (130) are fixedly connected by bolts, the top of the internal thread pipe (114) is fixedly provided with a heat preservation shell (132) on both sides, and the top of the heat preservation shell (132) is inserted into the inner wall of the corresponding protection seat (130), and the inner wall of the heat preservation shell (132) is fixedly provided with a coiled electric heating pipe (133).

3. The PVC-C large pipe fitting integrated molding injection molding machine according to claim 2, characterized in that, The top of the protection seat (130) is fixedly provided with a cover (134), and the bottom of the cover (134) is located in the right pipe opening of the three-prong pipe (111), the bottom of the cover (134) is fixedly provided with an extension rod (135), the bottom of the extension rod (135) is fixedly provided with a push cover (136), and the push cover (136) is sealingly and slidably connected to the inner wall of the right pipe opening of the three-prong pipe (111), the top of the push cover (136) is fixedly provided with a spring (137), the extension rod (135) is located in the spring (137), and the other end of the spring (137) is fixedly connected to the bottom of the cover (134).

4. The PVC-C large pipe fitting integrated molding injection molding machine according to claim 3, characterized in that, The outer wall of the protection seat (130) is fixedly provided with an air chamber (140), the inner wall of the air chamber (140) is sealingly and slidably connected with a piston rod (141), and the piston rod (141) sealingly and movably penetrates the top of the air chamber (140), the top and the bottom side wall of the air chamber (140) are provided with air guide holes (142), and the piston rod (141) is located between the two air guide holes (142), the top of the piston rod (141) is rotatably connected with a connecting arm (143), the top of the tapered plug pipe (115) is fixedly provided with a push pipe (116), the bottom outer wall of the push pipe (116) is provided with a clamping groove (117), the other ends of the two connecting arms (143) are clamped with the clamping groove (117), and the end walls of the two connecting arms (143) are fixedly connected by bolts, and the plug rod (120) is slidably connected with the inner wall of the push pipe (116).

5. The PVC-C large pipe fitting integrated molding injection molding machine according to claim 4, characterized in that, The protective seat (130) top two sides are provided with bayonet (131), two groups of protective seat (130) top is installed with the same top seat (150), the top seat (150) bottom four corners are provided with clamping block (152), and clamping block (152) is clamped with corresponding bayonet (131), the top seat (150) left side inner wall is fixedly installed with the through material pipe (151), and the through material pipe (151) is in sealed communication with the left side pipe orifice of the three-prong pipe (111), the top seat (150) top is provided with disc mouth (153), the push pipe (116) penetrates the middle part of the top seat (150), the push pipe (116) top and bottom outer wall are fixedly installed with the limiting disc (118), the limiting disc (118) located at the top is in movable contact with the disc mouth (153), the limiting disc (118) at the bottom is in movable contact with the top of the protective seat (130), the top of the top seat (150) is fixedly installed with the top frame (160), the top frame (160) top inner wall is fixedly installed with the cylinder one (161), and the output end of the cylinder one (161) is fixedly connected with the top of the plug rod (120).

6. The PVC-C large pipe fitting integrally formed injection molding machine according to claim 5, characterized in that, The melting device (200) comprises a support shell (210), the support shell (210) is provided with a metering area (211) on the inner wall of the front end, the inner wall of the metering area (211) is sealingly and slidably connected with a piston rod two (212), the support shell (210) is fixedly installed with a cylinder two (213) on the end wall, and the output end of the cylinder two (213) is fixedly connected with the end wall of the piston rod two (212), the front end wall of the support shell (210) is provided with a feeding channel (214), one end of the feeding channel (214) is in communication with the inside of the metering area (211), and the other end is in sealing communication with the through material pipe (151).

7. The PVC-C large pipe fitting integrally formed injection molding machine according to claim 6, characterized in that, The support shell (210) is fixedly installed with a sealing shell (220) on the top, the inner wall of the sealing shell (220) is rotatably connected with a hot melting spiral feeding rod (221), the inner wall of the middle part of the hot melting spiral feeding rod (221) is provided with a rod storage groove (222), the inner wall of the rod storage groove (222) is inserted with an anti-backflow rod (223), the outer wall of the sealing shell (220) is fixedly installed with a cylinder three (224), and the output end of the cylinder three (224) is fixedly connected with the end wall of the anti-backflow rod (223), the front end wall of the sealing shell (220) is provided with a material conveying channel (229), and the front end of the anti-backflow rod (223) can be clamped with the inner wall of the material conveying channel (229), the bottom of the material conveying channel (229) is in communication with the inside of the metering area (211), the end wall of the hot melting spiral feeding rod (221) is fixedly installed with a worm wheel (225), the inner wall of the sealing shell (220) is rotatably connected with a worm (226), and the worm (226) is engaged with the worm wheel (225), the top of the sealing shell (220) is fixedly installed with a motor (227), and the output end of the motor (227) is fixedly connected with the top of the worm (226), the top of the sealing shell (220) is provided with a material injection port (228), and the material injection port (228) is in communication with the hot melting spiral feeding rod (221).

8. The injection molding method of the PVC-C large pipe fitting integrated injection molding machine according to claim 7, characterized in that, Also include specific operation steps as follows: S1: through the injection port (228) to the sealing shell (220) and hot melt screw feeder (221) into the solid plastic raw materials, and then drive motor (227) to make it drive worm (225) worm (226) work, make hot melt screw feeder (221) rotation, forward conveying of solid raw materials, and in the process of conveying raw materials melting, through the material channel (229) will melt after the raw material into the metering area (211), so that the molten state of raw materials to push the piston rod two (212), and according to the displacement of piston rod two (212) calculation metering area (211) in the volume of raw materials; S2: in the injection molding machine work, stop injecting raw materials into the injection port (228), while driving cylinder three (224) to make it push the anti backflow rod (223) outward, make the anti backflow rod (223) block the material channel (229), while driving cylinder two (213) to make it push the piston rod two (212) outward, so as to inject the molten state of raw materials in the metering area (211) into the left side of the three pronged pipe (111) through the feeding channel (214) and the material pipe (151); S3: the raw material in the left side of the three pronged pipe (111) can flow into the inner threaded pipe (114) through the tapered runner (112), and finally flow into the mold through the bottom pipe of the inner threaded pipe (114), so as to form injection molding, in the process of injection molding, according to the required volume of the mold, when the injection molding is about to be completed, by injecting compressed gas into the air guide hole (142) at the top of the air chamber (140), the compressed gas extrudes the piston rod one (141) downward, so that the piston rod one (141) drives the connecting arm (143) downward, forcing the two groups of connecting arm (143) to press the push tube (116) downward, so that the push tube (116) drives the tapered plug tube (115) to move downward, forcing the tapered plug tube (115) to cooperate with the tapered runner (112), so as to reduce the molten state of raw materials flowing into the inner threaded pipe (114); S4: after the tapered plug tube (115) cooperates with the tapered runner (112), stop injecting raw materials in the metering area (211), when the injection molding is completed, by driving the cylinder one (161) to make its output shaft push the plug rod (120) outward, forcing the plug rod (120) to block the bottom pipe of the inner threaded pipe (114), so as to stop the supply of raw materials to the mold, complete the injection molding.

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