Injection molding mechanism without mold line

Abstract

The utility model discloses a kind of injection molding mechanisms of no moulding line, it is related to plastic product injection molding technical field, including base, heating tank, conveying outer tube, upper movable die and lower fixed die, the lower fixed die is fixedly connected on base in the base upper end, the lower fixed die below is provided with lifting plate, lifting plate upper end is fixedly connected with left and right two fixed columns, wherein fixed column is inserted in base and lower fixed die, lower fixed die upper end inner wall is provided with lower parting surface, lower fixed die upper end is provided with clamping groove, wherein upper and lower parting surface are slope structure, by mirror surface polishing and nanometer coating treatment, realize submicron level zero gap sealing when moulding, block melt overflow passage, eliminate the moulding line of moulding line produced by the problem of parting surface from root cause of traditional mould, forming piece precision, smoothness is high, and slope design makes upper movable die and lower fixed die can be automatically aligned and attached when moulding, without complex positioning mechanism, simplify mould structure, reduce the risk of positioning error to moulding line.

Description

Technical Field

[0001] This utility model relates to the field of injection molding technology for plastic products, specifically an injection molding mechanism without mold lines. Background Technology

[0002] In the field of plastic injection molding, mold line problems have long plagued the industry. Traditional injection molds rely on the parting surface for mold opening and closing. Due to the influence of mold processing precision, mechanical errors during mold closing, and wear after long-term use, gaps and misalignments easily appear on the parting surface, causing melt to overflow and form mold lines during injection. These mold lines not only severely damage the product's appearance and increase the cost of post-processing such as grinding and polishing, but also reduce the product's dimensional accuracy. The impact is even more significant for products with stringent requirements for surface quality and precision, such as optical lenses and high-end electronic device housings, and can even lead to product scrap.

[0003] While existing technologies attempt to reduce parting lines by optimizing mold materials, improving processing techniques, and employing hot runner technology, limitations remain. Firstly, minute errors at the mold parting surface are difficult to completely eliminate, and the positioning mechanism during mold closing is complex and prone to deviations due to mechanical vibration and hydraulic fluctuations. Secondly, uneven heating and unstable melt pressure during material melting and conveying indirectly increase the risk of melt overflow at the parting surface, failing to fundamentally solve the parting line problem. Therefore, those skilled in the art have provided a parting line-free injection molding mechanism to address the problems mentioned in the background section. Utility Model Content

[0004] The purpose of this invention is to provide an injection molding mechanism without mold lines to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] A mold-line-free injection molding mechanism includes a base, a heating tank, a conveying outer pipe, an upper moving mold, and a lower fixed mold. The lower fixed mold is fixedly connected to the upper end of the base. A lifting plate is located below the lower fixed mold, and two fixed columns are fixedly connected to the upper end of the lifting plate. The fixed columns are inserted into the base and the lower fixed mold. A lower parting surface is provided on the upper inner wall of the lower fixed mold, and a slot is formed at the upper end of the lower fixed mold. An upper moving mold is located above the lower fixed mold, and a locking block is fixedly connected to the lower end of the upper moving mold. The locking block can... The card is inserted into the slot. The card block has an upper parting surface around its perimeter. Both the upper and lower parting surfaces are sloped and are mirror-polished and treated with a nano-coating, allowing them to fit together precisely. A base plate is fixedly connected to the lower end of the base. A right support plate is fixedly connected to the upper right end of the base plate. A right fixed seat is fixedly connected to the upper end of the support plate. An outer conveying pipe is fixedly installed on the upper end of the fixed seat. An injection nozzle is fixedly connected and connected to the left end of the outer conveying pipe. The left end of the injection nozzle is fixedly connected and connected to the lower fixed mold.

[0007] As a further embodiment of this utility model: a support frame is fixedly connected to the upper end of the base, a hydraulic press is fixedly installed on the upper end of the support frame, a piston rod is provided at the lower end of the hydraulic press, wherein the lower end of the piston rod is fixedly connected to the upper moving mold, and two limiting rods are fixedly connected to the upper end of the upper moving mold, wherein the limiting rods are slidably connected to the support frame, a controller is fixedly installed on the front of the support frame, a first sliding groove is opened on one side of the base, a second sliding groove is opened on the other side of the base, a sliding rod is provided in the second sliding groove, wherein the upper and lower ends of the sliding rod are fixedly connected to the inner wall of the second sliding groove.

[0008] As a further embodiment of this utility model: a slider 1 is fixedly connected to one side of the lifting plate, wherein slider 1 is engaged in a slide groove 1; a slider 2 is fixedly connected to the other side of the lifting plate, wherein slider 2 is engaged in a slide groove 2, and slide groove 2 is slidably connected to a slide rod; a first servo motor is provided above slide groove 1, wherein the first servo motor is fixedly installed on the base; a threaded rod is fixedly connected to the power output end of the first servo motor, wherein the threaded rod is rotatably connected in slide groove 1, and slider 1 is threadedly connected to the threaded rod.

[0009] As a further embodiment of this utility model: a fixed frame is fixedly connected to the right end of the outer conveying pipe, a second servo motor is fixedly installed on the right side of the fixed frame, and a rotating shaft is fixedly connected to the power output end of the second servo motor. The rotating shaft is rotatably connected to the fixed frame and the outer conveying pipe. A main sprocket is fixedly connected to the outer wall of the rotating shaft, and a conveying screw is fixedly connected to the left end of the rotating shaft. The conveying screw is located inside the outer conveying pipe. When the conveying screw rotates, it can convey the molten material in the outer conveying pipe to the lower mold. A connecting pipe is fixedly connected and connected to the upper end of the outer conveying pipe. An electrically controlled valve is fixedly installed on the connecting pipe. A heating tank is fixedly connected and connected to the upper end of the connecting pipe. A spiral heating tube is arranged inside the inner wall of the heating tank. The spiral heating tube can heat and melt the plastic.

[0010] As a further embodiment of this utility model: the heating tank has a feed inlet at its upper end, and a sealing cap is threaded onto the feed inlet. A support block is fixedly connected to the upper end of the heating tank, and a movable rod is rotatably connected to the support block. A main bevel gear is fixedly connected to one end of the movable rod, and a driven sprocket is fixedly connected to the other end of the movable rod. A chain is provided between the main sprocket and the driven sprocket, wherein one end of the chain meshes with the main sprocket, and the other end of the chain meshes with the driven sprocket. Two side plates are fixedly connected to the upper end of the fixed base, wherein the side plates are fixedly connected to the heating tank. A rotating rod is rotatably connected to the heating tank, and a driven bevel gear is fixedly connected to the upper end of the rotating rod, wherein the main bevel gear and the driven bevel gear are in a meshing state. A stirring roller is fixedly connected to the rotating rod, wherein the stirring roller is located inside the heating tank, and the material can be stirred when the stirring roller rotates.

[0011] Compared with the prior art, the beneficial effects of this utility model are:

[0012] 1. Breakthrough in eliminating parting lines: The upper and lower parting surfaces adopt a sloping structure and are treated with a dual process of mirror polishing and nano-coating. This achieves a sub-micron level zero-gap seal during mold closing, eliminating the channels for melt overflow. This eliminates parting lines caused by gaps and misalignments in traditional molds. The surface smoothness and precision of the molded parts far exceed those of conventional injection molded parts, making it suitable for high-appearance requirements such as optical devices and high-end electronic housings. At the same time, the sloping parting surface design allows the upper moving mold and lower fixed mold to automatically align and fit precisely during mold closing, eliminating the need for complex positioning mechanisms. This simplifies the mold structure and ensures a sealing effect through physical optimization, reducing the risk of parting lines caused by positioning errors.

[0013] 2. Melt conveying coordinated control: The second servo motor synchronously drives the conveying screw and the stirring roller. When the material is in the heating tank, the stirring roller continuously homogenizes and stirs to avoid local overheating or uneven melting. After entering the outer conveying tube, the conveying screw pushes steadily to ensure uniform melt flow and pressure, stabilize the injection filling process, and reduce molding defects caused by uneven material.

[0014] 3. Heating efficiency and stability: The spiral heating tubes on the inner wall of the heating tank are arranged in a circular pattern, which, together with the stirring rollers, dynamically agitates the material. This results in a large heating area, uniform heat transfer, high melting efficiency, and controllable quality. It shortens the injection molding cycle, ensures the consistency of the physical properties of the melt, and improves the mechanical properties of the molded parts.

[0015] 4. Automation and Operational Advantages: The hydraulic press drives the upper moving mold to open / close, and the first servo motor links the lifting platen to eject the molded part. The actions are smooth and controllable. In addition, the controller integrates multi-motor and valve linkage logic, and the operator can complete the entire process of "mold closing-melting-injection-demolding" with simple commands, reducing the impact of manual intervention on molding quality, adapting to large-scale automated production, and improving the stability and efficiency of the production line. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of an injection molding mechanism without mold lines.

[0017] Figure 2 This is a schematic diagram of the base and support frame in an injection molding mechanism without mold lines.

[0018] Figure 3 This is a schematic diagram of the lifting plate and fixed column in an injection molding mechanism without mold lines.

[0019] Figure 4 This is a schematic diagram of the structure of the outer conveying tube and the second servo motor in an injection molding mechanism without mold lines.

[0020] Figure 5 This is a schematic diagram of the upper moving mold and hydraulic press in an injection molding mechanism without mold lines.

[0021] Figure 6 This is a schematic diagram of the lower mold in an injection molding mechanism without mold lines.

[0022] Figure 7 This is a schematic diagram of the conveying screw and stirring roller in an injection molding mechanism without mold lines.

[0023] In the diagram: 1. Base plate; 2. Slide groove one; 3. Slide groove two; 4. Slide rod; 5. First servo motor; 6. Threaded rod; 7. Lifting plate; 8. Slider one; 9. Slider two; 10. Fixed column; 11. Lower fixed mold; 12. Lower parting surface; 13. Slot; 14. Support frame; 15. Controller; 16. Hydraulic press; 17. Limit rod; 18. Upper moving mold; 19. Upper parting surface; 20. Locking block; 21. Support plate; 22. Fixed seat; 23. Side plate; 24. Heating tank; 25. Feed inlet; 26. Sealing cap; 27. Conveying outer pipe; 28. Injection molding outlet; 29. ​​Connecting pipe; 30. Electrically controlled valve; 31. Fixing frame; 32. Support block; 33. Second servo motor; 34. Rotating shaft; 35. Conveying screw; 36. Main sprocket; 37. Chain; 38. Driven sprocket; 39. Movable rod; 40. Main bevel gear; 41. Driven bevel gear; 42. Rotating rod; 43. Agitating roller; 44. Base. Detailed Implementation

[0024] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the present utility model will be further described below in conjunction with specific embodiments.

[0025] Please see Figures 1-7In this embodiment of the present invention, an injection molding mechanism without parting lines includes a base 44, a heating tank 24, a conveying outer pipe 27, an upper moving mold 18, and a lower fixed mold 11. The lower fixed mold 11 is provided on the upper end of the base 44 and is fixedly connected to the base 44. A lifting plate 7 is provided below the lower fixed mold 11, and two left and right fixed columns 10 are fixedly connected to the upper end of the lifting plate 7. The fixed columns 10 are inserted into the base 44 and the lower fixed mold 11. A lower parting surface 12 is provided on the upper inner wall of the lower fixed mold 11. A slot 13 is opened at the upper end of the lower fixed mold 11. An upper moving mold 18 is provided above the lower fixed mold 11. A locking block 20 is fixedly connected to the lower end of the upper moving mold 18. The locking block 20 can be locked into the slot 13. An upper parting surface 19 is provided around the locking block 20. Both the upper parting surface 19 and the lower parting surface 12 are sloped, and both are mirror-polished and treated with a nano-coating, allowing them to fit together precisely. A base plate 1 is fixedly connected to the lower end of the base 44. A right support plate 21 is fixedly connected to the upper right end of the base plate 1. A right fixed seat 22 is fixedly connected to the upper end of the support plate 21. A conveying outer pipe 27 is fixedly installed on the upper end of the fixed seat 22. An injection nozzle 28 is fixedly connected and connected to the left end of the conveying outer pipe 27. The injection nozzle 28 is fixedly connected and connected to the left end of the lower fixed mold 11. A support frame 14 is fixedly connected to the upper end of the base 44. A hydraulic press 16 is fixedly installed on the upper end of the support frame 14. A piston rod is provided at the lower end of the hydraulic press 16, and the lower end of the piston rod is fixedly connected to the upper moving mold 18. The upper moving mold 18 is fixedly connected to two front and rear limit rods 17, which are slidably connected to the support frame 14. The support frame 14 is fixedly installed with a controller 15 on the front. A slide groove 2 is opened on one side of the base 44, and a slide groove 3 is opened on the other side of the base 44. A slide rod 4 is set in the slide groove 3, and the upper and lower ends of the slide rod 4 are fixedly connected to the inner wall of the slide groove 3. A slider 8 is fixedly connected to one side of the lifting plate 7, and the slider 8 is locked in the slide groove 2. A slider 9 is fixedly connected to the other side of the lifting plate 7, and the slider 9 is locked in the slide groove 3. The slide groove 3 is slidably connected to the slide rod 4. A first servo motor 5 is set above the slide groove 2, and the first servo motor 5 is fixedly installed on the base 44. The first servo motor 5 is powered by... A threaded rod 6 is fixedly connected to the output end, and the threaded rod 6 is rotatably connected to the slide groove 2. The slider 8 is threadedly connected to the threaded rod 6. A fixed frame 31 is fixedly connected to the right end of the outer conveying tube 27. A second servo motor 33 is fixedly installed on the right side of the fixed frame 31. A rotating shaft 34 is fixedly connected to the power output end of the second servo motor 33. The rotating shaft 34 is rotatably connected to the fixed frame 31 and the outer conveying tube 27. A main sprocket 36 is fixedly connected to the outer wall of the rotating shaft 34. A conveying screw 35 is fixedly connected to the left end of the rotating shaft 34. The conveying screw 35 is located inside the outer conveying tube 27. When the conveying screw 35 rotates, it can convey the molten material in the outer conveying tube 27 to the lower mold. A connecting pipe 29 is fixedly connected and connected to the upper end of the outer conveying tube 27.An electrically controlled valve 30 is fixedly installed on the connecting pipe 29. A heating tank 24 is fixedly connected and communicated with the upper end of the connecting pipe 29. The heating tank 24 has a spiral heating tube installed inside its inner wall, which can heat and melt the plastic. A feed inlet 25 is opened at the upper end of the heating tank 24, and a sealing cap 26 is threaded onto the feed inlet 25. A support block 32 is fixedly connected to the upper end of the heating tank 24. A movable rod 39 is rotatably connected to the support block 32. A main bevel gear 40 is fixedly connected to one end of the movable rod 39, and a driven sprocket 38 is fixedly connected to the other end of the movable rod 39. The main sprocket 36 and the driven sprocket 38 are connected to each other. A chain 37 is installed between 8, with one end of the chain 37 meshing with the main sprocket 36 and the other end meshing with the driven sprocket 38. Two side plates 23 are fixedly connected to the upper end of the fixed base 22, and the side plates 23 are fixedly connected to the heating tank 24. A rotating rod 42 is rotatably connected to the heating tank 24, and a driven bevel gear 41 is fixedly connected to the upper end of the rotating rod 42. The main bevel gear 40 and the driven bevel gear 41 are meshed. A stirring roller 43 is fixedly connected to the rotating rod 42, and the stirring roller 43 is located inside the heating tank 24. When the stirring roller 43 rotates, it can stir the material.

[0026] The working principle of this utility model is as follows: First, the hydraulic press 16 is started, causing the piston rod to move the upper moving mold 18 downwards to engage with the lower fixed mold 11. The locking block 20 engages with the locking groove 13, and the upper parting surface 19 and the lower parting surface 12 (sloping structure) precisely fit together. Utilizing mirror polishing and nano-coating processes, a sub-micron level zero-gap seal is achieved to prevent melt overflow. Then, the plastic material can be poured into the heating tank 24 through the feed inlet 25, and the sealing cover 26 is placed on top. Next, the spiral heating tube is started to heat and melt the plastic. Then, the second servo motor 33 is started to drive the rotating shaft 34 to rotate. The rotating shaft 34 drives the main sprocket 36 to rotate, which in turn drives the chain 37 to rotate. The chain 37 drives the driven sprocket 38 to rotate, which in turn drives the movable rod 39 to rotate. The movable rod 39 drives the main bevel gear 40 to rotate, which in turn drives the driven bevel gear 41 to rotate. The driven bevel gear 41 then drives the rotating rod 42 to rotate. The rotating rod 42 drives the stirring roller 43 to rotate, which can stir and mix the material. At the same time, it can make the material heat evenly and melt more completely. Then, after melting, the electric control valve 30 is opened, allowing the molten material to flow into the outer conveying pipe 27. At this time, the rotating shaft 34 drives the conveying screw 35 to rotate. The conveying screw 35 can inject the molten material from the injection nozzle 28 into the cavity formed by the lower fixed mold 11 and the upper moving mold 18. Relying on the zero gap seal of the parting surface, it cools and solidifies in the cavity. Since there is no melt overflow, there are no parting lines on the surface of the molded part. Finally, after molding, the hydraulic press 16 is started again to move the upper moving mold 18 upward and separate it from the lower fixed mold 11. Then, the first servo motor 5 is started to drive the threaded rod 6 to rotate. The threaded rod 6 drives the slider 8 to move upward. The slider 8 drives the lifting plate 7 to move upward. The lifting plate 7 drives the fixed column 10 to move upward. The fixed column 10 pushes up to eject the molded part in the lower fixed mold 11, completing the demolding and part removal.

[0027] 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-line-free injection molding mechanism, comprising a base (44), a heating tank (24), a conveying outer pipe (27), an upper moving mold (18), and a lower fixed mold (11), characterized in that, The base (44) is provided with a lower fixed mold (11) at its upper end, wherein the lower fixed mold (11) is fixedly connected to the base (44), and a lifting plate (7) is provided below the lower fixed mold (11). The upper end of the lifting plate (7) is fixedly connected with two left and right fixed columns (10), wherein the fixed columns (10) are inserted into the base (44) and the lower fixed mold (11). The upper inner wall of the lower fixed mold (11) is provided with a lower parting surface (12), and a slot (13) is opened at the upper end of the lower fixed mold (11). An upper moving mold (18) is provided above the lower fixed mold (11), and the lower end of the upper moving mold (18) is fixedly connected with a... The card block (20) has an upper parting surface (19) around its perimeter. Both the upper parting surface (19) and the lower parting surface (12) are slopes. The base plate (1) is fixedly connected to the lower end of the base (44). The right support plate (21) is fixedly connected to the upper right end of the base plate (1). The right fixed seat (22) is fixedly connected to the upper end of the support plate (21). The upper end of the fixed seat (22) is fixedly installed with a conveying outer pipe (27). The left end of the conveying outer pipe (27) is fixedly connected to and connected to an injection nozzle (28). The left end of the injection nozzle (28) is fixedly connected to and connected to the lower fixed mold (11).

2. The injection molding mechanism without mold lines according to claim 1, characterized in that, The base (44) is fixedly connected to a support frame (14) at its upper end. A hydraulic press (16) is fixedly installed at the upper end of the support frame (14). A piston rod is provided at the lower end of the hydraulic press (16). The lower end of the piston rod is fixedly connected to the upper moving mold (18). Two limit rods (17) are fixedly connected at the upper end of the upper moving mold (18). The limit rods (17) are slidably connected to the support frame (14). A controller (15) is fixedly installed on the front of the support frame (14).

3. The injection molding mechanism without mold lines according to claim 1, characterized in that, The base (44) has a sliding groove 1 (2) on one side and a sliding groove 2 (3) on the other side. A sliding rod (4) is provided in the sliding groove 2 (3), and the upper and lower ends of the sliding rod (4) are fixedly connected to the inner wall of the sliding groove 2 (3).

4. The injection molding mechanism without mold lines according to claim 1, characterized in that, The lifting plate (7) is fixedly connected to a slider one (8) on one side, wherein the slider one (8) is locked in the slide groove one (2), and the lifting plate (7) is fixedly connected to a slider two (9) on the other side, wherein the slider two (9) is locked in the slide groove two (3), and the slide groove two (3) is slidably connected to the slide rod (4).

5. The injection molding mechanism without mold lines according to claim 3, characterized in that, A first servo motor (5) is provided above the slide groove (2), wherein the first servo motor (5) is fixedly installed on the base (44), and the power output end of the first servo motor (5) is fixedly connected to a threaded rod (6), wherein the threaded rod (6) is rotatably connected in the slide groove (2), and the slider (8) is threadedly connected to the threaded rod (6).

6. The injection molding mechanism without mold lines according to claim 1, characterized in that, The right end of the outer conveying pipe (27) is fixedly connected to a fixed frame (31), and a second servo motor (33) is fixedly installed on the right side of the fixed frame (31). The power output end of the second servo motor (33) is fixedly connected to a rotating shaft (34), which is rotatably connected to the fixed frame (31) and the outer conveying pipe (27).

7. The injection molding mechanism without mold lines according to claim 6, characterized in that, A main sprocket (36) is fixedly connected to the outer wall of the rotating shaft (34), and a conveying screw (35) is fixedly connected to the left end of the rotating shaft (34). The conveying screw (35) is located inside the conveying outer tube (27). A connecting pipe (29) is fixedly connected and connected to the upper end of the conveying outer tube (27). An electric control valve (30) is fixedly installed on the connecting pipe (29), and a heating tank (24) is fixedly connected and connected to the upper end of the connecting pipe (29).

8. The injection molding mechanism without mold lines according to claim 1, characterized in that, The heating tank (24) has a feed inlet (25) at the upper end, and a sealing cap (26) is threaded onto the feed inlet (25). A support block (32) is fixedly connected to the upper end of the heating tank (24), and a movable rod (39) is rotatably connected to the support block (32). A main bevel gear (40) is fixedly connected to one end of the movable rod (39), and a slave sprocket (38) is fixedly connected to the other end of the movable rod (39).

9. The injection molding mechanism without mold lines according to claim 7, characterized in that, A chain (37) is provided between the main sprocket (36) and the driven sprocket (38), wherein one end of the chain (37) is engaged with the main sprocket (36) and the other end of the chain (37) is engaged with the driven sprocket (38). The upper end of the fixed seat (22) is fixedly connected with two side plates (23), wherein the side plates (23) are fixedly connected to the heating tank (24).

10. The injection molding mechanism without mold lines according to claim 1, characterized in that, A rotating rod (42) is rotatably connected to the heating tank (24), and a bevel gear (41) is fixedly connected to the upper end of the rotating rod (42). The main bevel gear (40) and the bevel gear (41) are meshed. A stirring roller (43) is fixedly connected to the rotating rod (42), and the stirring roller (43) is located inside the heating tank (24).

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