A double tie rod clamping structure for a miniature precision injection molding machine

Abstract

A double-lever clamping structure for a micro-precision injection molding machine belongs to the field of injection molding machine technology. It solves the problems of uneven clamping force, easy displacement of the moving mold, poor mold adaptability, and insufficient clamping stability in existing clamping structures. The structure includes a machine body, a fixed base plate and a stationary plate at the top of the machine body, connected by four guide rods, with a moving plate slidably connected to the guide rods. Two clamping mechanisms are provided between the base plate and the moving plate. Each clamping mechanism includes a first support rod and a second support rod that rotate relative to each other. The bottom of the second support rod is connected to an extension plate and a connecting rod. A first hydraulic cylinder is located on the outside of the base plate, with its piston rod passing through the base plate and connecting to a push plate, which is hinged to two connecting rods. Two pairs of limiting mechanisms are provided on the moving plate, cooperating with the guide rods. The limiting mechanisms are connected to a drive rod driven by the double-extension hydraulic cylinder. The moving mold and the stationary mold are fixed to the moving plate and the stationary plate respectively, enabling precise clamping and secondary locking, adapting to different mold specifications, and used for stable production of micro-precision plastic parts.

Description

Technical Field

[0001] This utility model relates to the field of injection molding machine mold locking technology, and in particular to a double tie rod mold locking structure for a micro precision injection molding machine. Background Technology

[0002] Miniature precision injection molding machines are mainly used for the production of small-sized, high-precision plastic parts such as electronic components, medical accessories, and precision gears. These machines have much higher requirements for the precision and stability of the clamping structure than conventional injection molding machines. As a core component of the injection molding machine, the clamping structure directly affects the dimensional tolerances, surface quality, and production continuity of the plastic parts. Its performance determines whether the equipment can meet the process requirements of precision injection molding. Currently, most miniature injection molding machines on the market have clamping structures consisting of a single drive mechanism and a strut assembly to accommodate the compact layout of the equipment.

[0003] Existing mold-locking structures have revealed numerous problems in practical use. When a single drive mechanism moves the strut, the clamping force tends to concentrate locally, leading to uneven stress on the moving plate and slight tilting. This prevents the moving mold and stationary mold from fully fitting together, causing displacement of the moving mold under the pressure during injection molding, thus affecting the precision of the molded part. Furthermore, most structures lack a dedicated secondary locking design, relying solely on the rigidity of the strut itself to maintain the mold-locking state, resulting in insufficient stability. Therefore, a double-strut mold-locking structure for a micro-precision injection molding machine is proposed. Utility Model Content

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a double-pull-rod locking structure for a micro precision injection molding machine.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A double tie rod clamping structure for a micro precision injection molding machine includes a machine body, a base plate and a stationary plate fixedly connected to the top of the machine body, four guide rods fixedly connected between the base plate and the stationary plate, a movable plate slidably connected between the guide rods, and two clamping mechanisms provided between the base plate and the movable plate. The mold clamping mechanism includes a first support rod and a second support rod. The first support rod is rotatably connected to one side of the moving plate, and the second support rod is rotatably connected to one side of the base plate. The ends of the first support rod and the second support rod that are close to each other are rotatably connected. An inclined extension plate is integrally formed at the bottom of the second support rod. The extension plate is inclined toward one side of the base plate and a connecting rod is rotatably connected at the bottom. The first drive assembly is disposed on one side of the substrate and is used to drive the second strut to rotate; Two pairs of limiting mechanisms are set on the side of the moving plate near the base plate and are used in conjunction with the guide rods.

[0006] Furthermore, the first drive assembly includes a first hydraulic cylinder, which is fixed on the side of the base plate away from the moving plate. One end of the piston rod of the first hydraulic cylinder passes through the base plate and is fixedly connected to a push plate. The two ends of the push plate are respectively rotatably connected to two connecting rods.

[0007] Furthermore, the limiting mechanism includes a guide rail and multiple slots. The guide rail is fixed to one side of the moving plate, and a slide plate is slidably connected inside the guide rail. A screw is rotatably connected to one side of the slide plate, and a locking block is threaded onto the circumference of the screw. Multiple slots are evenly arranged on the side of the guide rod near the locking block. A positioning rod is fixedly connected to one side of the slide plate, and the positioning rod slides through the slide plate.

[0008] Furthermore, the end of the card block near the guide rod is arranged in a figure-eight shape, and the card slot has the same shape as the end of the card block.

[0009] Furthermore, a second drive assembly for driving the slide plate to move is also provided on one side of the moving plate. The second drive assembly includes a double-extension hydraulic cylinder. The piston rod ends on both sides of the double-extension hydraulic cylinder are fixedly connected to fixed seats. Drive rods are rotatably connected inside the fixed seats. The drive rods are rotatably connected to the slide plate respectively.

[0010] Furthermore, the screw is threaded with nuts around its circumference and abuts against the locking block.

[0011] Working principle: In this application, the moving mold and the stationary mold are respectively fixed on the side of the moving plate and the stationary plate that are close to each other. When the mold is closed, the first hydraulic cylinder is activated, and the first hydraulic cylinder drives the push plate to move. The push plate pushes the extension plate through the connecting rod, causing the second support rod to rotate. The second support rod pushes the first support rod, causing the moving plate to move. When the first support rod and the second support rod are horizontal, the moving mold and the stationary mold are tightly fitted together to complete the mold locking. During injection, the pressure inside the mold is transmitted to the first support rod and the second support rod to prevent the moving mold from moving. Before injection molding, the double-extension hydraulic cylinder is activated. The piston rod of the double-extension hydraulic cylinder pushes the slide plate to move through two drive rods. The slide plate drives the locking block to insert into the corresponding slot, thereby locking the moving plate a second time and further improving the stability of the moving plate. When the mold is different, the position of the locking block can also be finely adjusted by rotating the screw so that the locking block can be inserted into the slot, making it flexible to use.

[0012] Beneficial effects: In this utility model, the double tie rod locking structure of a micro precision injection molding machine is used in conjunction with the first hydraulic cylinder, push plate, and connecting rod of the first drive component and the first support rod, second support rod, and extension plate of the locking mechanism to drive the moving plate to slide smoothly along the guide rod until the first support rod and the second support rod are in a horizontal state, so that the moving mold and the stationary mold are tightly fitted. During injection, the rigid support rod is used to transmit the pressure inside the mold, effectively preventing the moving mold from shifting and ensuring the injection molding accuracy. At the same time, the linkage of the double locking mechanism improves the uniformity and reliability of the locking. In this invention, the double-pull-rod locking structure of a micro precision injection molding machine uses the guide rail, slide plate, locking block, and locking slot of the limiting mechanism in conjunction with the double-extension hydraulic cylinder and drive rod of the second drive component to perform secondary locking of the moving plate after molding. Combined with the setting of the screw and positioning rod, the position of the locking block can be finely adjusted to adapt to different mold specifications, ensuring that the locking block is accurately embedded in the locking slot, further enhancing the stability of the moving plate during the injection molding process and avoiding positional displacement caused by vibration or pressure fluctuations. Attached Figure Description

[0013] Figure 1 This is a three-dimensional schematic diagram of a double tie rod mold-locking structure for a miniature precision injection molding machine proposed in this utility model; Figure 2 This is a partial schematic diagram of a double tie rod mold-locking structure for a miniature precision injection molding machine proposed in this utility model; Figure 3 This is a schematic diagram of the limiting mechanism of the double tie rod mold locking structure of a micro precision injection molding machine proposed in this utility model.

[0014] In the diagram: 1. Body; 2. Base plate; 3. Stationary plate; 4. Guide rod; 5. Moving plate; 6. First hydraulic cylinder; 7. First support rod; 8. Second support rod; 9. Extension plate; 10. Connecting rod; 11. Push plate; 12. Limiting mechanism; 13. Guide rail; 14. Slide plate; 15. Screw; 16. Locking block; 17. Positioning rod; 18. Slot; 19. Double extension hydraulic cylinder; 20. Fixed base; 21. Drive rod. Detailed Implementation

[0015] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0016] In one embodiment: Refer to Figures 1-3 A mold-locking structure includes: a body 1, with a base plate 2 and a stationary plate 3 fixedly connected to the top of the body 1 by bolts. The base plate 2 and the stationary plate 3 are arranged in a parallel state, and four guide rods 4 are fixedly connected between them. The four guide rods 4 are arranged in a rectangular array. A moving plate 5 is slidably connected to the outer wall of the guide rods 4. The moving mold and the stationary mold used in injection molding are respectively fixed to the side of the moving plate 5 and the stationary plate 3 that are close to each other by clamps. Two symmetrically distributed mold-locking mechanisms are provided between the base plate 2 and the moving plate 5. The movement and mold-locking of the moving plate 5 are realized by the linkage of the two mold-locking mechanisms. Two pairs of limiting mechanisms 12 are also provided on the side of the moving plate 5 close to the base plate 2. The two pairs of limiting mechanisms 12 are used in conjunction with the guide rods 4 on both sides to perform secondary locking of the moving plate 5 and improve the stability after mold locking.

[0017] The mold-locking mechanism consists of a first support rod 7 and a second support rod 8. One end of the first support rod 7 is rotatably connected to the side of the moving plate 5 facing the base plate 2 via a pin, and one end of the second support rod 8 is rotatably connected to the side of the base plate 2 facing the moving plate 5 via a pin. The ends of the first support rod 7 and the second support rod 8 that are close to each other are rotatably connected via pins, so that the first support rod 7 and the second support rod 8 can form a foldable linkage structure. An extension plate 9 is integrally formed at the bottom of the second support rod 8. The extension plate 9 is inclined toward one side of the base plate 2. A connecting rod 10 is rotatably connected to the bottom of the extension plate 9 via a pin. A first driving assembly for driving the second support rod 8 to rotate is provided on one side of the base plate 2. The first driving assembly includes a first hydraulic cylinder 6. The first hydraulic cylinder 6 is fixed to the side of the base plate 2 away from the moving plate 5 by a mounting seat. The piston rod of the first hydraulic cylinder 6 is facing the moving plate 5, and one end of the piston rod passes through a through hole opened in the base plate 2 and is fixedly connected to a push plate 11. Its two ends are respectively rotatably connected to the ends of the connecting rods 10 of the two mold-locking mechanisms away from the extension plate 9 via pins. When mold closing is required, the first hydraulic cylinder 6 is activated, its piston rod extends and drives the push plate 11 to move closer to the moving plate 5. During the movement of the push plate 11, it pushes the extension plate 9 through the connecting rod 10. After the extension plate 9 is subjected to force, it drives the second support rod 8 to rotate around its connection point with the base plate 2. When the second support rod 8 rotates, it pushes the first support rod 7 to move synchronously, thereby driving the moving plate 5 to slide along the axis of the guide rod 4 towards the stationary plate 3 until the first support rod 7 and the second support rod 8 are in a horizontal state. At this time, the moving mold on the moving plate 5 and the stationary mold on the stationary plate 3 are tightly fitted, completing the mold locking operation. In the subsequent injection molding process, the pressure inside the mold will be directly transmitted to the first support rod 7 and the second support rod 8 in a horizontal state. The rigid support force of the support rods will prevent the moving mold from displacing, ensuring the accuracy of injection molding.

[0018] A PLC controller is fixedly installed inside the machine body 1. The PLC controller is electrically connected to the hydraulic control systems of the first hydraulic cylinder 6 and the double extension hydraulic cylinder 19.

[0019] The hydraulic system requires hydraulic oil to be changed every 3 months, and the hydraulic cylinder seals should be checked regularly and replaced in time if they are aged and leaking. The sliding parts such as guide rod 4 and guide rail 13 should be replenished with anti-oil grease every 15 working days. The threaded joint between screw 15 and locking block 16 should be cleaned of oil and debris every month to ensure precise locking. The inner wall of the slot 18 should be checked regularly, and the guide rod should be repaired or replaced if the wear exceeds 0.2mm.

[0020] This application can be used in the field of injection molding machine clamping, or in other fields applicable to this application.

[0021] In another embodiment: Reference Figures 1-3 A double-lever clamping structure for a micro precision injection molding machine is described, which is applied to the field of injection molding machine clamping. The structure of this embodiment is basically the same as that of the aforementioned embodiments, except that: Two pairs of limiting mechanisms 12 are respectively set for the guide rods 4 on both sides. The limiting mechanism 12 includes a guide rail 13 and multiple slots 18. The guide rail 13 is fixed to the side of the moving plate 5 facing the base plate 2 by bolts. A sliding plate 14 is slidably connected inside the guide rail 13. The sliding plate 14 can slide back and forth along the length of the guide rail 13. A screw 15 is rotatably connected to the side of the sliding plate 14 facing the guide rod 4 through a bearing. A locking block 16 is threaded on the outer circumference of the screw 15. Multiple slots 18 are evenly opened along the axial direction on the side of the guide rod 4 near the locking block 16. A positioning rod 17 is also fixedly connected to the side of the sliding plate 14 facing the guide rod 4. The axial direction of the positioning rod 17 is parallel to the axial direction of the screw 15. The positioning rod 17 slides through the sliding hole opened in the sliding plate 14 and extends to one side of the locking block 16, which guides the movement of the locking block 16. The end of the locking block 16 near the guide rod 4 is shaped like an "8". The internal shape of the slot 18 is adapted to the end shape of the locking block 16, ensuring that the locking block 16 can be stably and accurately embedded in the slot 18. A second drive assembly for driving the slide plate 14 to move is also provided on one side of the moving plate 5. The second drive assembly includes a double-extension hydraulic cylinder 19, which is fixed to the side of the moving plate 5 by a bracket. Its two piston rods are respectively set towards the limiting mechanism 12 on both sides, and the ends of the piston rods are fixedly connected to the fixed seats 20. The drive rod 21 is rotatably connected to the inside of the fixed seat 20 by a pin. The end of the drive rod 21 away from the fixed seat 20 is rotatably connected to the slide plate 14 by a pin. After initial mold clamping and before injection molding begins, the double-extension hydraulic cylinder 19 is activated, and its piston rods extend synchronously. Through the fixed base 20, the drive rod 21 moves. Under force, the drive rod 21 causes the slide plate 14 to slide along the guide rail 13 towards the guide rod 4. As the slide plate 14 moves, it causes the locking block 16 to simultaneously approach the guide rod 4 until the end of the locking block 16 is embedded in the corresponding slot 18 on the guide rod 4. Through the locking engagement between the locking block 16 and the slot 18, the position of the moving plate 5 is locked a second time, further improving the stability of the moving plate 5 during injection molding. When changing to molds of different specifications, causing misalignment between the locking block 16 and the slot 18, the screw 15 can be manually rotated. Utilizing the threaded engagement between the screw 15 and the locking block 16, the locking block 16 is finely adjusted along the axial direction of the screw 15, allowing it to accurately insert into the slot 18, adapting to the mold clamping requirements of different molds. A nut is also threaded onto the outer circumference of the screw 15. When the nut is tightened, it will abut against the side of the locking block 16. The self-locking property of the thread is used to fix the position of the locking block 16, preventing it from shifting during use and ensuring the locking effect of the limiting mechanism 12.

[0022] However, as is well known to those skilled in the art, the working principles and wiring methods of the first hydraulic cylinder 6 and the double-extension hydraulic cylinder 19 are commonplace and are all conventional methods or common knowledge. They will not be elaborated here. Those skilled in the art can make any selections according to their needs or convenience.

[0023] The accompanying drawings in this application are for illustrative purposes only. The dimensions and shapes of the components shown are not actual limitations but are merely schematic representations. In actual implementation, the components can be reasonably configured and adjusted according to specific needs and actual conditions.

[0024] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A double-pull-rod locking structure for a micro precision injection molding machine, comprising a machine body (1), a base plate (2) and a stationary plate (3) fixedly connected to the top of the machine body (1), four guide rods (4) fixedly connected between the base plate (2) and the stationary plate (3), and a movable plate (5) slidably connected between the guide rods (4), characterized in that, Two mold-locking mechanisms are provided between the substrate (2) and the moving plate (5); The mold clamping mechanism includes a first support rod (7) and a second support rod (8). The first support rod (7) is rotatably connected to one side of the moving plate (5), and the second support rod (8) is rotatably connected to one side of the base plate (2). The first support rod (7) and the second support rod (8) are rotatably connected at their close ends. An inclined extension plate (9) is integrally formed at the bottom of the second support rod (8). The extension plate (9) is inclined toward one side of the base plate (2) and a connecting rod (10) is rotatably connected at its bottom. The first driving component is disposed on one side of the substrate (2) for driving the second support rod (8) to rotate; Two pairs of limiting mechanisms (12) are set on the side of the moving plate (5) near the base plate (2) and are used in conjunction with the guide rod (4).

2. The double tie rod clamping structure of a micro precision injection molding machine according to claim 1, characterized in that, The first drive assembly includes a first hydraulic cylinder (6), which is fixed on the side of the base plate (2) away from the moving plate (5). One end of the piston rod of the first hydraulic cylinder (6) passes through the base plate (2) and is fixedly connected to a push plate (11). The two ends of the push plate (11) are rotatably connected to two connecting rods (10) respectively.

3. The double tie rod clamping structure of a micro precision injection molding machine according to claim 1, characterized in that, The limiting mechanism (12) includes a guide rail (13) and multiple slots (18). The guide rail (13) is fixed on one side of the moving plate (5). A slide plate (14) is slidably connected inside the guide rail (13). A screw (15) is rotatably connected to one side of the slide plate (14). A locking block (16) is threadedly connected to the circumference of the screw (15). Multiple slots (18) are evenly arranged on the side of the guide rod (4) near the locking block (16). A positioning rod (17) is fixedly connected to one side of the slide plate (14). The positioning rod (17) slides through the slide plate (14).

4. The double tie rod clamping structure of a micro precision injection molding machine according to claim 3, characterized in that, The end of the card block (16) near the guide rod (4) is arranged in a figure-eight shape, and the card slot (18) has the same shape as the end of the card block (16).

5. The double-pull-rod clamping structure of a micro precision injection molding machine according to claim 4, characterized in that, A second drive assembly for driving the sliding plate (14) to move is also provided on one side of the moving plate (5). The second drive assembly includes a double-extension hydraulic cylinder (19). The piston rod ends on both sides of the double-extension hydraulic cylinder (19) are fixedly connected to a fixed seat (20). The fixed seat (20) is rotatably connected to a drive rod (21). The drive rod (21) is rotatably connected to the sliding plate (14) respectively.

6. The double tie rod clamping structure of a micro precision injection molding machine according to claim 3, characterized in that, The screw (15) is threaded with nuts around its circumference and abuts against the locking block (16).

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