A die closing mechanism for a pipe injection molding machine

Abstract

This utility model discloses a mold closing mechanism for a pipe fitting injection molding machine. A plurality of sliding guide rods are fixedly connected between a first fixed plate and a second fixed plate. A fixed template is slidably connected to one side of the sliding guide rod on the first fixed plate. A plurality of mounting blocks are fixedly connected to one side of the fixed template, and the mounting blocks are fixedly connected to one side of the first fixed plate by bolts. A fixed mold assembly is fixedly connected to the other side of the fixed template. A movable template is slidably connected to the sliding guide rod on one side of the second fixed plate. One side of the movable template is connected to the push rod of a hydraulic cylinder. The hydraulic cylinder is fixedly connected to the middle of the second fixed plate. A movable mold assembly is fixedly connected to the other side of the movable template. The movable mold assembly and the fixed mold assembly are interlocked. The purpose of this utility model is to provide a mold closing mechanism with precise positioning, stable and controllable mold closing pressure, and efficient and reliable demolding process.

Description

Technical Field

[0001] This utility model relates to the technical field of mold closing mechanism for injection molding machines, specifically a mold closing mechanism for a pipe injection molding machine. Background Technology

[0002] In the manufacturing of plastic products, pipe fittings, due to their regular internal and external cavity structures, are widely used in fluid transportation, mechanical connections, and other applications. Injection molding, with its high production efficiency, good consistency, and ability to mold complex structures, has become one of the mainstream technologies for pipe fitting manufacturing. The mold clamping mechanism, as the core functional component of the injection molding machine, directly affects the molding quality, production efficiency, and equipment reliability of the pipe fittings. Its performance plays a decisive role in the dimensional accuracy, surface quality, and production stability of the final product.

[0003] Currently, existing mold-closing mechanisms used in pipe injection molding mainly employ a combination of hydraulic drive and mechanical guidance. They typically use guide pillars and guide sleeves to guide the relative movement of the moving and fixed mold plates, and utilize hydraulic cylinders to provide the closing power. However, as pipe products become more precise and complex, traditional mold-closing mechanisms are gradually revealing the following shortcomings: First, insufficient positioning accuracy. While traditional guide pillars and guide sleeves can provide basic guidance, they are susceptible to equipment vibration or load fluctuations during high-speed mold closing, leading to positioning deviations between the fixed and moving mold plates, resulting in cavity misalignment and affecting the dimensional accuracy and appearance quality of the pipe fittings. Second, poor mold-closing pressure stability. Some mechanisms rely on the rigid pressure of the hydraulic system to directly drive the moving mold plate. When hydraulic oil pressure fluctuates or the mold wears, the mold-closing pressure is prone to momentary insufficient or overload phenomena, potentially leading to poor cavity sealing (generating flash or burrs) or localized stress concentration in the mold (causing mold damage). Third, low demolding efficiency. Traditional mechanisms rely entirely on hydraulic cylinders to reverse-drive the moving platen during mold opening. Separating the top and bottom molds of pipe fittings requires an additional ejection device, which not only increases the complexity of the equipment but may also lead to pipe fitting deformation or core mold breakage due to improper ejection force control, affecting production efficiency and product yield.

[0004] Therefore, there is an urgent need to design a mold closing mechanism for a pipe injection molding machine that is precise in positioning, has stable and controllable mold closing pressure, and is efficient and reliable in the demolding process, so as to meet the high-quality production requirements of precision pipes. Utility Model Content

[0005] In view of the above-mentioned shortcomings in the existing technology, the purpose of this utility model is to provide a mold closing mechanism that is accurate in positioning, stable and controllable in mold closing pressure, and efficient and reliable in the demolding process.

[0006] The technical solution adopted by this utility model to achieve the above objectives is as follows: a mold closing mechanism for a pipe fitting injection molding machine, comprising sliding guide rods, a first fixed plate, a second fixed plate, a fixed template, a moving template, a hydraulic cylinder, a fixed mold assembly, and a moving mold assembly. A plurality of sliding guide rods are fixedly connected between the first fixed plate and the second fixed plate, and the sliding guide rods are respectively arranged at the four corners of the first and second fixed plates. A fixed template is slidably connected to a sliding guide rod on one side of the first fixed plate. Sliding guide holes are respectively opened at the four corners of the fixed template, and the sliding guide rods are slidably connected within the sliding guide holes. A fixed template is fixedly connected to a hydraulic cylinder on one side of the fixed template. Several mounting blocks are attached, which are fixedly connected to one side of the first fixed plate by bolts. A fixed mold assembly is fixedly connected to the other side of the fixed mold. A movable mold is slidably connected to a sliding guide rod located on one side of the second fixed plate. The four corners of the movable mold are also provided with sliding guide holes for the sliding guide rod to slide. One side of the movable mold is connected to the push rod of a hydraulic cylinder. The hydraulic cylinder is fixedly connected to the middle of the second fixed plate. The movable mold slides linearly along the sliding guide rod through the hydraulic cylinder. A movable mold assembly is fixedly connected to the other side of the movable mold. The movable mold assembly and the fixed mold assembly are interlocked and connected.

[0007] In the above technical solution, the fixed mold assembly includes a first mold base, a limiting pin, a pipe injection molding bottom mold, and an injection molding connecting pipe. The first mold base is fixedly connected to one side of the fixed mold plate by a fixing member, and the other side of the first mold base is fixedly connected to the pipe injection molding bottom mold.

[0008] In the above technical solution, the moving mold assembly includes a second mold base, a sliding block, a telescopic rod, a helical spring, and a pipe injection mold. The second mold base is fixedly connected to one side of the moving mold base by a fixing member. The second mold base has two sets of symmetrical sliding holes. A sliding block is slidably connected in each sliding hole. After the sliding block passes through the sliding hole, it is fixedly connected to the edge of the pipe injection mold. Mounting holes are respectively opened on the second mold base between the sliding holes. Spring grooves are respectively opened at the openings of the mounting holes. A telescopic rod is fixedly connected in the mounting hole. The other end of the telescopic rod passes through the mounting hole and is fixedly connected to the pipe injection mold. A helical spring is sleeved on the telescopic rod. One end of the helical spring abuts against the bottom surface of the spring groove, and the other end of the helical spring abuts against the pipe injection mold.

[0009] In the above technical solution, a first groove is provided on one side of the bottom mold of the pipe fitting, and a plurality of fixed pin holes are provided on the outer periphery of the first groove. A second groove is provided on one side of the top mold of the pipe fitting, and a plurality of positioning pins are fixedly connected to the outer periphery of the second groove. The positioning pins are respectively inserted into the fixed pin holes.

[0010] In the above technical solution, the first groove and the second groove form a cavity with each other, a mold core is fixedly connected in the cavity, an injection tube is fixedly connected in the middle of the first mold base, one end of the injection tube is connected to the first groove through the injection channel, and through holes are opened in the middle of the fixed template and the first fixed plate, and the injection tube is inserted into the through holes.

[0011] In the above technical solution, the inner walls of the first groove and the second groove are respectively provided with air holes, and the openings of the air holes are respectively provided with sealing mechanisms. The outer walls of the bottom mold and the top mold of the pipe fitting are respectively provided with threaded holes, and the other end of the air holes is respectively connected to the threaded holes.

[0012] The beneficial effects of this utility model are:

[0013] 1. Significantly improved positioning accuracy: The positioning pins on the moving mold assembly and the positioning pin holes on the fixed mold assembly are connected by a plug-in fit. When the moving mold plate moves to the fixed mold plate, the positioning pins are inserted into the positioning pin holes first to complete the pre-positioning. This avoids the template offset caused by equipment vibration or load fluctuation during high-speed mold closing, ensuring precise cavity alignment and effectively improving the dimensional accuracy and appearance quality of the formed pipe fittings.

[0014] 2. Enhanced Mold Closing Pressure Stability: After the moving platen continues to move and completes the initial contact between the bottom mold and the top mold, the helical spring is compressed and stores energy, continuously acting on the top mold through its elastic force, forming an elastic buffer structure. Compared to the rigid pressure of traditional hydraulic direct drive, this design can effectively offset pressure changes caused by hydraulic fluctuations or mold wear, avoiding flash and burrs caused by instantaneous insufficient pressure, or mold stress damage caused by pressure overload, thus ensuring the stability of the mold closing process.

[0015] 3. Improved demolding efficiency and simplified operation: During mold opening, the hydraulic cylinder drives the moving platen backward, and the helical spring gradually stretches from a compressed state, while the bottom mold and top mold remain closed. When the helical spring returns to its initial length, the telescopic rod extends with the spring, pulling the top mold to move, achieving smooth separation of the bottom mold and top mold. This process eliminates the need for an additional ejection device, simplifying the mechanism and avoiding problems such as pipe deformation or core mold breakage caused by excessive ejection force from an additional ejection device. In addition, the gas stripping method improves demolding efficiency and product yield. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0017] Figure 2 This is a top view of the structure of this utility model;

[0018] Figure 3 This is a schematic diagram of the cross-sectional connection structure of the moving mold assembly of this utility model;

[0019] Figure 4 for Figure 3 Detailed structural diagram of part A1 in the middle;

[0020] Figure 5 This is a cross-sectional disassembly diagram of the fixed mold assembly and the moving mold assembly of this utility model;

[0021] Figure 6 for Figure 5 Detailed structural diagram of part A2 in the middle.

[0022] In the diagram: 1. Sliding guide rod, 2. First fixed plate, 3. Second fixed plate, 4. Fixed template, 5. Moving template, 6. Hydraulic cylinder, 7. Fixed mold assembly, 8. Moving mold assembly, 9. Mounting block, 101. First mold base, 102. Pipe injection bottom mold, 201. Second mold base, 202. Sliding block, 203. Telescopic rod, 204. Helical spring, 205. Pipe injection top mold, 206. Sliding hole, 207. Mounting hole, 208. Spring groove, 301. First groove, 302. Second groove, 303. Positioning pin, 304. Positioning pin hole, 401. Injection tube, 402. Injection channel, 403. Through hole, 404. Mold core, 501. Air hole, 502. Sealing mechanism, 503. Threaded hole. Detailed Implementation

[0023] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0024] Please see Figure 1-6 A mold closing mechanism for a pipe fitting injection molding machine includes sliding guide rods 1, a first fixed plate 2, a second fixed plate 3, a fixed mold plate 4, a moving mold plate 5, a hydraulic cylinder 6, a fixed mold assembly 7, and a moving mold assembly 8. Several sliding guide rods 1 are fixedly connected between the first fixed plate 2 and the second fixed plate 3, and the sliding guide rods 1 are respectively arranged at the four corners of the first and second fixed plates 3. A fixed mold plate 4 is slidably connected to a sliding guide rod 1 on one side of the first fixed plate 2. Sliding guide holes are respectively opened at the four corners of the fixed mold plate 4, and the sliding guide rods 1 are slidably connected within the sliding guide holes. Several mounting blocks are fixedly connected to one side of the fixed mold plate 4. 9. Mounting block 9 is fixedly connected to one side of the first fixed plate 2 by bolts. Fixed mold assembly 7 is fixedly connected to the other side of the fixed template 4. Moving template 5 is slidably connected to the sliding guide rod 1 located on one side of the second fixed plate 3. The four corners of the moving template 5 are also provided with sliding guide holes for the sliding guide rod 1 to slide. One side of the moving template 5 is connected to the top rod of the hydraulic cylinder 6. The hydraulic cylinder 6 is fixedly connected to the middle of the second fixed plate 3. The moving template 5 slides linearly along the sliding guide rod 1 through the hydraulic cylinder 6. Moving mold assembly 8 is fixedly connected to the other side of the moving template 5. Moving mold assembly 8 and fixed mold assembly 7 are interlocked and connected.

[0025] In the above technical solution, the fixed mold assembly 7 includes a first mold base 101, a limiting pin, a pipe injection bottom mold 102, and an injection molding connecting pipe. The first mold base 101 is fixedly connected to one side of the fixed mold plate 4 by a fixing member, and the pipe injection bottom mold 102 is fixedly connected to the other side of the first mold base 101. The moving mold assembly 8 includes a second mold base 201, a sliding block 202, a telescopic rod 203, a coil spring 204, and a pipe injection top mold 205. The second mold base 201 is fixedly connected to one side of the moving mold plate 5 by a fixing member. The second mold base 201 has two sets of symmetrical sliding groove holes 206. Sliding groove blocks 202 are slidably connected within each sliding groove hole 206. After passing through the sliding groove hole 206, the sliding groove blocks 202 are fixedly connected to the edge of the pipe fitting injection mold 205. Mounting holes 207 are respectively formed on the second mold base 201 between the sliding groove holes 206. Spring grooves 208 are respectively formed at the openings of the mounting holes 207. Telescopic rods 203 are fixedly connected within the mounting holes 207, with the other end of the telescopic rods 203 passing through the mounting holes 208. 7. The tube is fixedly connected to the top mold 205 of the pipe fitting injection molding. A helical spring 204 is sleeved on the telescopic rod 203. One end of the helical spring 204 abuts against the bottom surface of the spring groove 208, and the other end of the helical spring 204 abuts against the top mold 205 of the pipe fitting injection molding. A first groove 301 is opened on one side of the bottom mold 102 of the pipe fitting injection molding. Several fixed pin holes 304 are opened on the outer periphery of the first groove 301. A second groove 302 is opened on one side of the top mold 205 of the pipe fitting injection molding. The outer periphery of the second groove 302 is fixed. The fixed connection has several positioning pins 303, which are respectively inserted into the pin holes 304; the first groove 301 and the second groove 302 form a cavity with each other, and the mold core 404 is detachably connected in the cavity; the injection tube 401 is fixedly connected to the middle of the first mold base 101, and one end of the injection tube 401 is connected to the first groove 301 through the injection channel 402; the fixed template 4 and the first fixed plate 2 are both provided with through holes 403 in the middle, and the injection tube 401 is inserted into the through holes 403;

[0026] In the above scheme, the mold closing process is as follows: the moving mold plate 5 is pushed to the fixed mold plate 4 by the hydraulic cylinder 6, and the positioning pin 303 on the moving mold assembly 8 is inserted into the fixed pin hole 304, thereby completing the precise positioning of the fixed mold assembly 7 and the moving mold assembly 8. After that, the moving mold plate 5 continues to move to the fixed mold plate 4, thereby completing the mold closing state of the pipe injection bottom mold 102 and the pipe injection top mold 205. Then, the spiral spring 204 is compressed. The spiral spring 204 forms elastic energy storage in the compressed state, and the spring force acts on one side of the pipe injection top mold 205. The spring force ensures the tight contact between the pipe injection bottom mold 102 and the pipe injection top mold 205. At this time, the first groove 301 and the second groove 302 between the pipe injection bottom mold 102 and the pipe injection top mold 205 form a closed cavity.

[0027] The injection molding process is as follows: molten plastic enters the first molded groove 301 and the second molded groove 302 (cavity) through the injection tube 401, and is then held under pressure and cooled after filling.

[0028] The mold opening process is as follows: the hydraulic cylinder 6 drives the template 5 to move backward. First, the helical spring 204 is gradually stretched from the compressed state. During this process, the bottom mold 102 and the top mold 205 of the pipe injection are still in the closed state. After the helical spring 204 returns to the initial state, the telescopic rod 203 reaches the maximum extension length. Then, the second mold base 201 pulls the top mold 205 of the pipe injection through the telescopic rod 203 to move, so that the bottom mold 102 and the top mold 205 of the pipe injection are separated from each other. Then, the molded pipe in the cavity is removed, and the mold core 404 in the pipe is taken out to complete the molding process.

[0029] In this invention, the inner walls of the first groove 301 and the second groove 302 are respectively provided with air holes 501, and sealing mechanisms 502 are respectively provided at the openings of the air holes 501. The outer walls of the pipe injection bottom mold 102 and the pipe injection top mold 205 are respectively provided with threaded holes 503. The other end of the air hole 501 is connected to the threaded hole 503. After the mold is opened, the sealing mechanism 502 automatically opens the opening of the air hole 501. The air supply device is connected to the threaded hole 503 and outputs high-pressure gas. The high-pressure gas enters the first groove 301 or the second groove 302 through the air hole 501. The high-pressure gas quickly peels off the pipes that are stuck in the groove. In this invention, the sealing mechanism 502 can be driven by a motor to complete the sealing or opening operation of the opening.

[0030] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0031] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A mold closing mechanism for a pipe fitting injection molding machine, comprising a sliding guide rod (1), a first fixed plate (2), a second fixed plate (3), a fixed mold plate (4), a moving mold plate (5), a hydraulic cylinder (6), a fixed mold assembly (7), and a moving mold assembly (8), characterized in that: A plurality of sliding guide rods (1) are fixedly connected between the first fixed plate (2) and the second fixed plate (3). A fixed template (4) is slidably connected to the sliding guide rod (1) on one side of the first fixed plate (2). A plurality of mounting blocks (9) are fixedly connected to one side of the fixed template (4). The mounting blocks (9) are fixedly connected to one side of the first fixed plate (2) by bolts. A fixed mold assembly (7) is fixedly connected to the other side of the fixed template (4). A movable template (5) is slidably connected to the sliding guide rod (1) on one side of the second fixed plate (3). One side of the movable template (5) is connected to the top rod of the hydraulic cylinder (6). The hydraulic cylinder (6) is fixedly connected to the middle of the second fixed plate (3). A movable mold assembly (8) is fixedly connected to the other side of the movable template (5). The movable mold assembly (8) and the fixed mold assembly (7) are interlocked. The fixed mold assembly (7) includes a first mold base (101) and a pipe injection bottom mold (102). The first mold base (101) is fixedly connected to one side of the fixed mold plate (4) by a fastener, and the other side of the first mold base (101) is fixedly connected to the pipe injection bottom mold (102). The moving mold assembly (8) includes a second mold base (201), a sliding block (202), a telescopic rod (203), a helical spring (204), and a pipe injection mold (205). The second mold base (201) is fixedly connected to one side of the moving mold plate (5) by a fixing member. The second mold base (201) has two sets of symmetrical sliding holes (206). Sliding blocks (202) are slidably connected in each of the sliding holes (206). After the sliding blocks (202) pass through the sliding holes (206), they are fixedly connected to the edge of the pipe injection mold (205). The first set of sliding holes (206) between the sliding holes (206) is... The two mold bases (201) are respectively provided with mounting holes (207), and spring grooves (208) are respectively provided at the openings of the mounting holes (207). A telescopic rod (203) is fixedly connected in the mounting holes (207). The other end of the telescopic rod (203) passes through the mounting holes (207) and is fixedly connected to the top mold of the pipe fitting injection (205). A helical spring (204) is sleeved on the telescopic rod (203). One end of the helical spring (204) abuts against the bottom surface of the spring groove (208), and the other end of the helical spring (204) abuts against the top mold of the pipe fitting injection (205). The bottom mold (102) for pipe fitting injection molding has a first groove (301) on one side, and a plurality of fixed pin holes (304) are provided on the outer periphery of the first groove (301). The top mold (205) for pipe fitting injection molding has a second groove (302) on one side, and a plurality of positioning pins (303) are fixedly connected to the outer periphery of the second groove (302). The positioning pins (303) are respectively inserted into the fixed pin holes (304).

2. A clamp mechanism for a tube injection molding machine according to claim 1, characterized in that: The first groove (301) and the second groove (302) form a cavity with each other. A mold core (404) is fixedly connected in the cavity. An injection tube (401) is fixedly connected in the middle of the first mold base (101). One end of the injection tube (401) is connected to the first groove (301) through the injection channel (402). A through hole (403) is opened in the middle of the fixed template (4) and the first fixed plate (2). The injection tube (401) is inserted into the through hole (403).

3. A clamp mechanism for a tube injection molding machine according to claim 2, wherein: The inner walls of the first type groove (301) and the second type groove (302) are respectively provided with air holes (501), and the openings of the air holes (501) are respectively provided with sealing mechanisms (502). The outer walls of the pipe fitting injection bottom mold (102) and the pipe fitting injection top mold (205) are respectively provided with threaded holes (503), and the other end of the air hole (501) is connected to the threaded hole (503).

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