A mold clamping device for an automated injection molding machine

Abstract

This invention provides a mold clamping device for an automated injection molding machine, applicable to the field of mold clamping devices. Through the cooperation between the mold clamping device, which includes a first cylinder, a steering pipe, and a critical valve, and a mold clamping frame with an air jet, in actual use, when the hydraulic mechanism drives the moving mold to move closer to the fixed mold for mold clamping, the first piston moves synchronously in the first cylinder, generating positive pressure. On one hand, the positive pressure within the first piston buffers the mold clamping between the moving and fixed molds, and the buffering force gradually increases, effectively preventing the moving mold from generating a large impact force on the moving mold under inertial motion. This improves the injection accuracy and service life of the mold. On the other hand, the positive pressure can be transmitted to the air jet for a mold cleaning process before injection molding. This invention has a simple structure, strong mold clamping protection, and market potential, making it suitable for widespread application.

Description

Technical Field

[0001] This application relates to the field of mold clamping devices, and in particular to a mold clamping device for an automated injection molding machine. Background Technology

[0002] The working principle of an injection molding machine is similar to that of a syringe. It uses the thrust of a screw (or plunger) to inject pre-plasticized molten plastic (i.e., a viscous flow state) into a closed mold cavity, where it solidifies and shapes to obtain the finished product. Injection molding machines are classified into plunger-type and screw-type injection molding machines based on their plasticizing method; hydraulic, mechanical, and hydraulic-mechanical (linkage) types based on their transmission method; and automatic, semi-automatic, and manual injection molding machines based on their operation method. Injection molding machines require a mold clamping device to control the merging of the two molds during operation.

[0003] An existing patent (publication number: CN214324086U) discloses a mold clamping device for an injection molding machine, relating to the technical field of mold clamping devices. It includes a lower base, a first fixed plate, a second fixed plate, a hydraulic cylinder, a fixed template, a movable template, a locking mechanism, and a demolding mechanism. Several support columns are evenly distributed at the bottom of the lower base. The first and second fixed plates are symmetrically fixed to the left and right sides of the upper surface of the lower base. The hydraulic cylinder is fixed to the outside of the second fixed plate. Four tie rods arranged in a rectangular array are fixed between the first and second fixed plates.

[0004] In the process of implementing this solution, the inventors discovered the following problems in the existing technology that have not been well resolved: the device does not have a buffer protection function, and long-term collision between the two molds during the mold closing process will cause mold deformation and reduce service life; after injection molding, the device is inconvenient to remove, and an additional ejection mechanism is required. Therefore, we propose a mold closing device for an automated injection molding machine to solve the above problems. Summary of the Invention

[0005] The purpose of this application is to design a mold clamping device with mold clamping protection function, mold cleaning and material ejection functions, so as to improve the quality of injection molded products. Compared with the prior art, this application provides a mold clamping device for an automated injection molding machine. Through the structural design of the mold clamping device and the injection molding machine and mold mounted on the frame, the mold includes two sets of fixed seats fixed on the frame. A slide rod is fixed between the two sets of fixed seats. A synchronous slide, a material ejection slide and a moving mold are slidably connected on the slide rod. A fixed mold matching the moving mold is fixed on one fixed seat, and a hydraulic mechanism is fixed on the other fixed seat. The output end of the hydraulic mechanism is connected to the synchronous slide. The slide and the moving mold are fixedly connected. The ejector slide is provided with an ejector rod corresponding to the moving mold. The mold closing device includes a first cylinder fixed on the fixed mold, a first piston matching the first cylinder fixed on the moving mold, a rotatable guide tube connected to the bottom of the first cylinder, a pressure relief hole on one side of the guide tube, a positive pressure port and a negative pressure port symmetrically provided on the first cylinder, two sets of symmetrically arranged limit blocks fixed at the end of the guide tube, a return spring and a pressure bladder clamped between the limit blocks and the inner wall of the first cylinder, and a critical valve for connecting the first cylinder and the guide tube at a set pressure value at the end of the guide tube.

[0006] The critical valve includes a valve chamber fixed to the end of the diversion tube. Two sets of symmetrically arranged diaphragm springs are fixed in the valve chamber. Each diaphragm spring is fixed with a valve plug. The valve chamber is provided with a valve seat that matches the valve plug. Magnets are fixed to the opposite ends of the two sets of valve plugs. Each valve plug is provided with a one-way valve. One-way valve on one side is used to prevent positive pressure gas from entering the valve chamber, and one-way valve on the other side is used to prevent gas in the diversion tube from entering the valve chamber.

[0007] A mold closing frame is sleeved on the side of the fixed mold. Several air jets are evenly spaced on the inner side of the mold closing frame. The output end of the positive pressure interface is connected to the input end of the air jets.

[0008] Furthermore, the mold closing frame protrudes from the mold closing end face of the fixed mold, and the centers of the air jets on both sides of the mold closing frame are staggered and located on both sides of the mold closing end face.

[0009] Furthermore, the magnets on the two sets of valve plugs have a magnetic attraction force, and the magnetic attraction force generated when the two sets of magnets are displaced to the minimum stroke is greater than the elastic force of the diaphragm spring.

[0010] Furthermore, the return spring is a high-strength fatigue-resistant spring structure, and the return spring has the elastic force to drive the steering tube to rotate and keep the pressure relief hole and the positive pressure interface misaligned and closed.

[0011] Furthermore, the air pressure bladder has a sealed bladder structure, and the air pressure inside the air pressure bladder is less than the maximum air pressure generated by compression in the first cylinder.

[0012] Furthermore, sealing rings are fixed on both sides of the pressure relief hole in the steering pipe.

[0013] Furthermore, a second cylinder is fixed on the synchronous slide, and a second piston matching the second cylinder is fixed on the unloading slide. A tension spring is clamped between the second piston and the second cylinder, and the input end of the second cylinder is connected to the output end of the negative pressure interface.

[0014] Furthermore, the tension spring is a high-strength fatigue-resistant spring structure, and the tension spring has the elastic force to drive the ejector slide close to the synchronous slide.

[0015] Furthermore, the second cylinder, under the negative pressure input from the negative pressure interface, drives the ejector slide to overcome the elastic force of the tension spring and move away from the synchronous slide.

[0016] Compared to existing technologies, the advantages of this application are:

[0017] (1) By designing the center of the two air jets to be staggered and located on both sides of the mold closing end face, when air pressure is generated in the air jet, relative and parallel airflow will be generated. In this way, before the fixed mold and moving mold are closed, impurities in the injection cavity of the mold can be blown away quickly, which effectively improves the injection molding yield.

[0018] (2) The first piston squeezes the first cylinder to generate positive pressure. When the positive pressure value is greater than the air pressure inside the air pressure bladder, the air pressure bladder will contract, which will drive the return spring to retract, thereby realizing the rotation of the steering tube under positive pressure and maintaining the connection between the pressure relief hole and the positive pressure interface.

[0019] (3) The present invention utilizes the cooperation between the mold closing device with a first cylinder, a steering pipe, and a critical valve and the mold closing frame with an air jet. In actual use, when the hydraulic mechanism drives the moving mold to move closer to the fixed mold for mold closing, the first piston moves synchronously in the first cylinder and generates positive pressure. On the one hand, the positive pressure inside the first piston provides a buffer for the mold closing between the moving mold and the fixed mold, and the buffer force gradually increases, thereby effectively avoiding the large impact force on the moving mold under inertial action. This improves the injection precision and service life of the mold.

[0020] (4) On the other hand, when the mold closing is completed, the positive pressure generated in the first cylinder reaches the design critical value, which compresses the air pressure bladder. At this time, the air pressure bladder expands under this negative pressure. With the help of the return spring, the steering tube rotates and keeps the pressure relief hole aligned with the positive pressure interface. At the same time, the positive pressure generated in the first cylinder is greater than the spring force of the diaphragm spring. The diaphragm spring drives the valve plug away from the first cylinder to move, so that the valve chamber opens and the positive pressure is transmitted to the jet nozzle, which is the cleaning process of the mold before injection molding. The present invention has a simple structure, strong mold closing protection, market prospects, and is suitable for promotion and application.

[0021] (5) In this embodiment, after the injection molding is completed in the mold, the moving mold moves away from the fixed mold under the drive of the hydraulic mechanism, thereby driving the first piston to perform a suction action in the first cylinder and generate negative pressure. Under this negative pressure, the air pressure bladder expands, and with the elastic force of the return spring, the steering tube rotates and keeps the pressure relief hole and the negative pressure interface connected. When the negative pressure generated in the first cylinder is greater than the elastic force of the diaphragm spring, the diaphragm spring drives the valve plug away from the first cylinder to move, so that the valve chamber opens and the negative pressure is transmitted to the second cylinder. The second cylinder is driven by the negative pressure input from the negative pressure interface, which drives the ejector slide to overcome the elastic force of the tension spring and move away from the synchronous slide. The ejector rod ejects the injection molded product in the moving mold and completes the ejection action. Since the first cylinder needs time to generate critical negative pressure, it provides time for the cooling of the injection molded product in the moving mold. The design is simple and the ejection is convenient. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the front structure of this application;

[0023] Figure 2 This is a side view of the structure of this application;

[0024] Figure 3 This is a cross-sectional structural diagram of the mold proposed in this application;

[0025] Figure 4 for Figure 3 Enlarged structural diagram of section A in the middle;

[0026] Figure 5 for Figure 3 Enlarged structural diagram of section B in the middle;

[0027] Figure 6 for Figure 3 Enlarged structural diagram of section C;

[0028] Figure 7 This is an exploded structural diagram of the mold closing device proposed in this application;

[0029] Figure 8 This is a schematic diagram of the internal structure of the first cylinder proposed in this application;

[0030] Figure 9 This is a schematic diagram of the explosive structure of the critical valve proposed in this application;

[0031] Figure 10 This is a schematic diagram of the internal cross-sectional structure of the valve chamber proposed in this application.

[0032] Explanation of the labels in the diagram:

[0033] Frame 1, Injection Molding Machine 2, Mold 3, Fixed Base 31, Slide Rod 311, Fixed Mold 32, Moving Mold 33, Synchronous Slide 34, Second Cylinder 341, Hydraulic Mechanism 35, Unloading Slide 36, Ejector Rod 361, Second Piston 362, Tension Spring 363, Mold Closing Device 4, First Cylinder 41, Positive Pressure Interface 411, Negative Pressure Interface 412, Diverting Pipe 42, Sealing Ring 421, Pressure Relief Hole 422, Limiting Block 423, Return Spring 43, Air Pressure Bag 44, Critical Valve 45, Diaphragm Spring 451, Valve Plug 452, Magnet 453, One-Way Valve 454, First Piston 46, Mold Closing Frame 5, Air Jet Port 51, Valve Chamber 6. Detailed Implementation

[0034] The embodiments will be described clearly and completely with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments in this application without creative effort are within the scope of protection of this application.

[0035] Example 1:

[0036] This invention provides a mold clamping device for an automated injection molding machine. Please refer to [link / reference]. Figure 1-10 The system includes a mold closing device 4, an injection molding machine 2 mounted on a frame 1, and a mold 3. The mold 3 includes two sets of fixed seats 31 fixed on the frame 1, with a slide rod 311 fixed between the two sets of fixed seats 31. A synchronous slide 34, a ejector slide 36, and a moving mold 33 are slidably connected on the slide rod 311. A fixed mold 32 matching the moving mold 33 is fixed on one of the fixed seats 31, and a hydraulic mechanism 35 is fixed on the other fixed seat 31. The output end of the hydraulic mechanism 35 is fixedly connected to the synchronous slide 34 and the moving mold 33. The ejector slide 36 is provided with an ejector rod 361 corresponding to the moving mold 33. The mold closing device 4 includes a fixed mold on the fixed mold. The first cylinder 41 on the 32 is fixed with a first piston 46 that matches the first cylinder 41 on the moving mold 33. The bottom of the first cylinder 41 is rotatably connected to a steering pipe 42. A pressure relief hole 422 is provided on one side of the steering pipe 42. A positive pressure port 411 and a negative pressure port 412 are symmetrically provided on the first cylinder 41. Two sets of symmetrically arranged limiting blocks 423 are fixed at the end of the steering pipe 42. A return spring 43 and a pressure bladder 44 are clamped between the limiting block 423 and the inner wall of the first cylinder 41. The end of the steering pipe 42 is also provided with a critical valve 45 for connecting the first cylinder 41 and the steering pipe 42 under a set pressure value.

[0037] The critical valve 45 includes a valve chamber 6 fixed to the end of the diverting pipe 42. Two sets of symmetrically arranged diaphragm springs 451 are fixed in the valve chamber 6. Each diaphragm spring 451 is fixed with a valve plug 452. The valve chamber 6 is provided with a valve seat that matches the valve plug 452. A magnet 453 is fixed to one end of each set of valve plugs 452. Each valve plug 452 is provided with a one-way valve 454. One-way valve 454 on one side is used to prevent positive pressure gas from entering the valve chamber 6, and one-way valve 454 on the other side is used to prevent gas in the diverting pipe 42 from entering the valve chamber 6.

[0038] A mold closing frame 5 is sleeved on the side of the fixed mold 32. Several air jets 51 are evenly distributed on the inner side of the mold closing frame 5. The output end of the positive pressure interface 411 is connected to the input end of the air jets 51.

[0039] It should be noted that in this embodiment, the mold closing frame 5 protrudes from the mold closing end face of the fixed mold 32, and the centers of the air jets 51 on both sides of the mold closing frame 5 are staggered and located on both sides of the mold closing end face.

[0040] By designing the centers of the two air jets 51 to be staggered and located on both sides of the mold closing end face, when air pressure is generated in the air jets 51, relative and intersecting parallel airflows will be generated. In this way, before the fixed mold 32 and the moving mold 33 are closed, impurities in the injection cavity of the mold 3 can be quickly blown away, effectively improving the injection molding yield.

[0041] Among them, the magnets 453 on the two sets of valve plugs 452 have magnetic attraction between them. When the two sets of magnets 453 are displaced to the minimum stroke, the magnetic attraction generated is greater than the elastic force of the diaphragm spring 451. The return spring 43 is a high-strength fatigue-resistant spring structure. The return spring 43 has the elastic force to drive the steering tube 42 to rotate and keep the pressure relief hole 422 and the positive pressure interface 411 misaligned and closed. The air pressure bladder 44 is a sealed bladder structure. The air pressure value filled in the air pressure bladder 44 is less than the maximum air pressure generated by compression in the first cylinder 41. The steering tube 42 is also fixed with sealing rings 421 on both sides of the pressure relief hole 422.

[0042] The first piston 46 compresses the first cylinder 41 to generate positive pressure. When the positive pressure value is greater than the internal air pressure of the air pressure bladder 44, the air pressure bladder 44 will contract, causing the return spring 43 to retract, thereby enabling the steering pipe 42 to rotate under positive pressure and maintaining the connection between the pressure relief hole 422 and the positive pressure interface 411.

[0043] This invention utilizes the interaction between a mold-closing device 4 with a first cylinder 41, a steering pipe 42, and a critical valve 45, and a mold-closing frame 5 with an air jet 51. In actual use, when the hydraulic mechanism 35 drives the moving mold 33 to move closer to the fixed mold 32 for mold-closing action, the first piston 46 performs a synchronous displacement action in the first cylinder 41 and generates positive pressure. On the one hand, the positive pressure in the first piston 46 provides a buffer for the mold-closing between the moving mold 33 and the fixed mold 32, and the buffering force gradually increases, thereby effectively avoiding the large impact force on the moving mold 33 under inertial action. This improves the injection precision and service life of the mold 3.

[0044] On the other hand, when the mold closing is completed, the positive pressure generated in the first cylinder 41 reaches the design critical value, causing the air pressure bladder 44 to compress. At this time, the air pressure bladder 44 expands under this negative pressure, and with the elastic force of the return spring 43, the steering tube 42 rotates, and the pressure relief hole 422 and the positive pressure interface 411 are kept aligned. At the same time, the positive pressure generated in the first cylinder 41 is greater than the elastic force of the diaphragm spring 451. The diaphragm spring 451 drives the valve plug 452 away from the first cylinder 41 to move, so that the valve chamber 6 opens and the positive pressure is transmitted to the jet nozzle 51, which is the cleaning process of the mold 3 before injection molding. The present invention has a simple structure, strong mold closing protection, market prospects, and is suitable for promotion and application.

[0045] Example 2:

[0046] This invention provides a mold clamping device for an automated injection molding machine. Please refer to [link / reference]. Figure 1-10 Components that are the same as or corresponding to those in Embodiment 1 are referred to by the same reference numerals as those in Embodiment 1. For the sake of simplicity, only the differences from Embodiment 1 will be described below:

[0047] In this embodiment, a second cylinder 341 is also fixed on the synchronous slide 34, and a second piston 362 matching the second cylinder 341 is fixed on the unloading slide 36. A tension spring 363 is clamped between the second piston 362 and the second cylinder 341. The input end of the second cylinder 341 is connected to the output end of the negative pressure interface 412.

[0048] Among them, the tension spring 363 is a high-strength fatigue-resistant spring structure. The tension spring 363 has the elastic force to drive the ejector slide 36 to approach the synchronous slide 34. The second cylinder 341 is subjected to the negative pressure input by the negative pressure port 412, which drives the ejector slide 36 to overcome the elastic force of the tension spring 363 and move away from the synchronous slide 34.

[0049] In this embodiment, after injection molding is completed in mold 3, the moving mold 33 moves away from the fixed mold 32 under the drive of the hydraulic mechanism 35, thereby driving the first piston 46 to perform a suction action in the first cylinder 41 and generate negative pressure. Under this negative pressure, the air pressure bladder 44 expands, and with the elastic force of the return spring 43, the steering pipe 42 rotates, and the pressure relief hole 422 and the negative pressure interface 412 are kept in contact. When the negative pressure generated in the first cylinder 41 is greater than the elastic force of the diaphragm spring 451, the diaphragm spring 451 drives the moving mold 33 away from the fixed mold 32. The valve plug 452 of the first cylinder 41 is displaced, opening the valve chamber 6. Negative pressure is transmitted to the second cylinder 341. The second cylinder 341, under the negative pressure input from the negative pressure port 412, drives the ejector slide 36 to overcome the elastic force of the tension spring 363 and move away from the synchronous slide 34. The ejector rod 361 ejects the injection molded product in the moving mold 33, completing the ejection action. Since the first cylinder 41 needs time to generate critical negative pressure, it provides time for the injection molded product in the moving mold 33 to cool down. The design is simple and the ejection is convenient.

[0050] The above description is only the best implementation method adopted in this application in combination with current practical needs, but the scope of protection of this application is not limited thereto.

Claims

1. A mold closing device for an automated injection molding machine, comprising a mold closing device (4) and an injection molding machine (2) and a mold (3) mounted on a frame (1), wherein the mold (3) comprises two sets of fixed seats (31) fixed on the frame (1), a slide rod (311) is fixed between the two sets of fixed seats (31), a synchronous slide (34), a ejector slide (36) and a moving mold (33) are slidably connected on the slide rod (311), a fixed mold (32) matching the moving mold (33) is fixed on one side of the fixed seat (31), and a hydraulic mechanism (35) is fixed on the other side of the fixed seat (31), wherein the output end of the hydraulic mechanism (35) is fixedly connected to the synchronous slide (34) and the moving mold (33), and an ejector rod (361) corresponding to the moving mold (33) is provided on the ejector slide (36), characterized in that, The mold closing device (4) includes a first cylinder (41) fixed on the fixed mold (32), a first piston (46) matching the first cylinder (41) fixed on the moving mold (33), a steering tube (42) rotatably connected to the bottom of the first cylinder (41), a pressure relief hole (422) provided on one side of the steering tube (42), a positive pressure port (411) and a negative pressure port (412) symmetrically provided on the first cylinder (41), two sets of symmetrically arranged limiting blocks (423) fixed at the end of the steering tube (42), a return spring (43) and a pressure bladder (44) clamped between the limiting block (423) and the inner wall of the first cylinder (41), and a critical valve (45) for connecting the first cylinder (41) and the steering tube (42) under a set pressure value at the end of the steering tube (42). The critical valve (45) includes a valve chamber (6) fixed to the end of the diverting pipe (42). Two sets of symmetrically arranged diaphragm springs (451) are fixed in the valve chamber (6). Each diaphragm spring (451) is fixed with a valve plug (452). The valve chamber (6) is provided with a valve seat that matches the valve plug (452). A magnet (453) is fixed to one end of each of the two sets of valve plugs (452). Each valve plug (452) is provided with a one-way valve (454). One side of the one-way valve (454) is used to prevent positive pressure gas from entering the valve chamber (6), and the other side of the one-way valve (454) is used to prevent gas in the diverting pipe (42) from entering the valve chamber (6). The fixed mold (32) is fitted with a mold closing frame (5) on its side. The inner side of the mold closing frame (5) is provided with a plurality of air jets (51) at equal intervals. The output end of the positive pressure interface (411) is connected to the input end of the air jets (51).

2. The mold clamping device for an automated injection molding machine according to claim 1, characterized in that, The mold closing frame (5) protrudes from the mold closing end face of the fixed mold (32), and the centers of the air jets (51) on both sides of the mold closing frame (5) are offset and located on both sides of the mold closing end face.

3. The mold clamping device for an automated injection molding machine according to claim 1, characterized in that, There is a magnetic attraction between the magnets (453) on the two sets of valve plugs (452), and the magnetic attraction generated when the two sets of magnets (453) are displaced to the minimum stroke is greater than the elastic force of the diaphragm spring (451).

4. The mold clamping device for an automated injection molding machine according to claim 1, characterized in that, The reset spring (43) is a high-strength fatigue-resistant spring structure. The reset spring (43) has the elastic force to drive the steering tube (42) to rotate and keep the pressure relief hole (422) and the positive pressure port (411) misaligned and closed.

5. The mold clamping device for an automated injection molding machine according to claim 4, characterized in that, The air pressure bladder (44) is a closed bladder structure, and the air pressure value filled in the air pressure bladder (44) is less than the maximum air pressure generated by compression in the first cylinder (41).

6. The mold clamping device for an automated injection molding machine according to claim 1, characterized in that, The steering pipe (42) is also fixed with sealing rings (421) on both sides of the pressure relief hole (422).

7. The mold clamping device for an automated injection molding machine according to claim 1, characterized in that, A second cylinder (341) is also fixed on the synchronous slide (34), and a second piston (362) matching the second cylinder (341) is fixed on the unloading slide (36). A tension spring (363) is clamped between the second piston (362) and the second cylinder (341). The input end of the second cylinder (341) is connected to the output end of the negative pressure interface (412).

8. The mold clamping device for an automated injection molding machine according to claim 7, characterized in that, The tension spring (363) is a high-strength fatigue-resistant spring structure, and the tension spring (363) has an elastic force that drives the ejector slide (36) to approach the synchronous slide (34).

9. The mold clamping device for an automated injection molding machine according to claim 8, characterized in that, The second cylinder (341) is subjected to negative pressure input from the negative pressure port (412), which drives the material ejection slide (36) to move away from the synchronous slide (34) against the elastic force of the tension spring (363).

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