A multi-directional threaded core-pulling mold

Abstract

This utility model relates to the field of mold forming technology, including injection molding and metal injection molding, specifically to a multi-directional threaded core-pulling mold. This utility model, through the precise structural design and coordinated operation of two sets of mechanisms, comprehensively solves the core defects of existing technologies, achieving significant improvements in multi-directional adaptability, precision, space efficiency, and synchronization. The specific solution includes a slider, rack one, rack two, a hydraulic cylinder, a cylinder base, and gears five and six arranged coaxially. Rack two is driven and connected by the hydraulic cylinder, and gear five meshes with rack two. The slider is equipped with a longitudinal core-pulling mechanism and a transverse core-pulling mechanism to achieve multi-directional threaded core pulling.

Description

Technical Field

[0001] This utility model relates to the field of mold forming technology such as injection molding and metal injection molding, and specifically to a multi-directional threaded core-pulling mold. Background Technology

[0002] In molding processes such as injection molding and metal injection molding, threaded core-pulling molds are a key technology for products with threaded structures. Traditional threaded core-pulling molds typically use a sliding block mechanism to handle external undercuts and an angled ejector mechanism to handle internal undercuts, achieving product demolding by dividing difficult-to-machine parts of the mold into movable components. Some molds also use gear transmission and other methods for threaded core pulling, but existing technologies still have certain limitations for multi-directional threaded core pulling.

[0003] Patent CN201620698124.6 discloses a threaded core-pulling mechanism. This mechanism includes a hydraulic cylinder with a U-shaped connector. A rack is fixed inside the U-shaped connector and meshes with a first gear. A second gear is coaxially mounted on the first gear, and the second gear is connected to a threaded core-pulling assembly. The threaded core-pulling assembly includes a dial, a third gear, a positioning element, a rear film insert, and a threaded core-pulling insert. The dial, third gear, positioning element, and rear film insert are coaxially arranged from bottom to top, with the threaded core-pulling insert positioned above the rear film insert. Its advantage is that thread positioning can be achieved through the dial, ensuring that the starting position of the thread can be corrected at any time. However, it has the following problems: 1. Single-direction core pulling: The core pulling design can only be used for threads in a single direction. For example, it can only handle internal or external threads of the product. For products with multi-directional threads (such as axial and radial threads at the same time), it is difficult to achieve one-time molding and demolding. It often requires multiple sets of molds or complex secondary processing, which increases production costs and production cycle.

[0004] 2. Difficulty in guaranteeing accuracy: Traditional molds processed by slanted tops or internal core pulling are prone to minor step differences or burrs on the product during production due to the influence of processing accuracy and fitting clearance. This is especially true for high-precision threaded products, which are difficult to meet the requirements of consistent thread direction and smooth tooth grooves, resulting in a low product qualification rate and making it inconvenient for mass production.

[0005] 3. Large space occupation: The excessive pulling distance of the transmission method will cause waste of effective space inside the mold, resulting in an increase in mold volume. This is not conducive to the compact design and miniaturization of the mold, and also increases the manufacturing and use costs of the mold.

[0006] 4. Poor Synchronization: For some molds that require simultaneous core pulling in multiple directions, it is difficult to ensure the synchronization of each core pulling mechanism. If the core pulling is not synchronized, it can easily lead to product deformation and damage, affecting product quality. Moreover, existing molds have large motion timing errors when multiple core pulling mechanisms are linked, making it difficult to meet the production requirements of high-precision products. Summary of the Invention

[0007] In view of this, in order to solve the problems of existing core-pulling molds having a single core-pulling direction, requiring multiple core-pulling molds to work in multiple directions, poor synchronization, and large space occupation, this utility model provides a multi-directional threaded core-pulling mold.

[0008] To achieve the purpose of this utility model, the technical solution of this utility model is: a multi-directional threaded core-pulling mold, including a rack two, a hydraulic cylinder, a cylinder base, and gear five and gear six arranged coaxially on the upper and lower sides. The rack two is driven and connected by the hydraulic cylinder, and gear five and rack two mesh. The feature is that it also includes a slider and a rack one. The slider is respectively provided with a longitudinal core-pulling mechanism and a transverse core-pulling mechanism to realize axial and radial core-pulling respectively. The longitudinal core-pulling mechanism includes two threaded rods arranged side by side and vertically on the slider. Each threaded rod is fitted with a threaded mandrel II. The threaded rods are threadedly connected to the threaded mandrel II. Each threaded mandrel II is fixed with a gear IV. The transverse core-pulling mechanism includes two threaded rods arranged side by side on the slider. Each threaded rod is fitted with a threaded mandrel 1, and the threaded rod is threadedly connected to the threaded mandrel 1. Each threaded mandrel 2 is fixed with a gear 3, and a gear 2 is arranged between the two gear 3s. The gear 2 meshes with the two gear 3s. The gear 2 is arranged on a connecting shaft 1, and a gear 1 is also arranged on the connecting shaft 1. The gear 1 meshes with a rack 1.

[0009] Furthermore, each threaded rod has a threaded limit block at the other end.

[0010] Furthermore, bearings two and three are respectively installed at the upper and lower ends of the shafts of gear five and gear six.

[0011] Furthermore, a bearing is provided on the connecting shaft.

[0012] Compared with the prior art, the advantages of this utility model are as follows: 1) This utility model integrates two independent mechanisms, and the combination of the two mechanisms realizes one-time molding and demolding of multi-directional threads in "axial + radial" direction, without the need for multiple molds or secondary processing.

[0013] 2) This utility model improves the core-pulling accuracy and eliminates the displacement error of traditional mechanisms through precise structural design.

[0014] 3) This utility model has a compact structure, optimizes the spatial layout, and reduces the overall volume of the mold.

[0015] 4) This utility model ensures that there is no lag in power transmission through gear meshing and no elastic deformation.

[0016] 5) This utility model has a thread limit block at the end of the threaded rod to restrict the movement of the threaded mandrel and avoid deviation. It also uses a slider for auxiliary positioning to further reduce motion deviation. Attached image description: Figure 1 This is a schematic diagram of the structure of this utility model.

[0017] Figure 2 This is a diagram of the transverse core-pulling mechanism of this utility model.

[0018] Figure 3 This is a diagram of the longitudinal core-pulling mechanism of this utility model.

[0019] Markings: 1. Bearing 1; 2. Threaded limiting block 1; 3. Gear 1; 4. Rack 1; 5. Connecting shaft 1; 6. Gear 2; 7. Gear 3; 8. Threaded mandrel 1; 9. Slider; 10. Threaded mandrel 2; 11. Gear 4; 12. Threaded limiting block 2; 13. Bearing 2; 14. Gear 5; 15. Gear 6; 16. Bearing 3; 17. Rack 2; 18. Cylinder base; 19. Hydraulic cylinder. Detailed implementation method: In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] This embodiment provides a multi-directional threaded core-pulling mold, such as Figure 1-3 As shown, it includes longitudinal and transverse core-pulling mechanisms, which respectively realize axial core-pulling and radial core-pulling.

[0022] like Figure 3As shown, the longitudinal core-pulling mechanism includes two threaded rods arranged side by side and vertically on the slider 9. Each threaded rod is fitted with a threaded mandrel 10, and the threaded rod is threadedly connected to the threaded mandrel 10. Each threaded mandrel 10 is fixed with a gear 11. Threaded limit blocks 12 are respectively provided on the two threaded rods. Gear 14 meshes with rack 17. Gear 15 is coaxially arranged on the upper part of gear 14. Bearings 13 and 16 are respectively provided at the upper and lower ends of the shafts of gear 14 and gear 15. Rack 17 is driven and connected by a hydraulic cylinder 19, which is mounted on a cylinder base 18.

[0023] like Figure 2 As shown, the transverse core-pulling mechanism includes two threaded rods arranged side-by-side on the slider 9. Each threaded rod is fitted with a threaded mandrel 8, and the threaded rod is threadedly connected to the threaded mandrel 8. Each threaded mandrel 10 is fixed with a gear 7, and a gear 6 is arranged between the two gears 7. The gear 6 meshes with the two gears 7. The gear 6 is arranged on the connecting shaft 5, and a gear 3 is also arranged on the connecting shaft 5. The gear 3 meshes with the rack 4. Threaded limit blocks 2 are arranged on the two threaded rods respectively, and bearings 1 are arranged on the connecting shaft 5. The transverse mechanism is driven by the opening and closing force of the upper and lower templates when the mold is opened.

[0024] The working process of this utility model is as follows: Figure 1 As shown: Before mold opening, the hydraulic system is activated. The longitudinal core-pulling mechanism extends through the piston rod of the hydraulic cylinder 19, driving rack 2 17 to move. Rack 17 meshes with gear 5 14, which in turn drives the coaxial gear 6 15 to rotate. Gear 6 15 meshes with gear 4 11, which in turn drives the threaded mandrel 2 10 to move up and down on the threaded rod, converting the rotational motion into the linear motion of the rack and achieving a rigid transmission chain. When the mold opens, the transverse core-pulling mechanism drives gear 1 3 to rotate through rack 1 4. Gear 1 3 drives the coaxial gear 2 6 to rotate, which in turn meshes with gear 3 7, enabling the threaded mandrel 1 8 to move back and forth on the threaded rod, achieving a rigid transmission chain. The gear set meshing has no elastic deformation, ensuring no lag in power transmission. Rack 1 4 moves up and down by the opening and closing force of the upper and lower mold plates of each mold set, which is existing technology and will not be repeated here.

[0025] Limiting and assisting: Thread limit block 12 and thread limit block 212 respectively limit the movement direction of thread mandrel 18 and thread mandrel 210 to avoid deviation; slider 9 assists in positioning the transverse core pulling mechanism to further reduce motion deviation.

[0026] Ultimately, the synchronization error of multi-directional core pulling is ≤0.1mm, and the product deformation is ≤0.074mm, meeting the requirements for high-precision product manufacturing. Utility model transmission accuracy guarantee: In the bottom mechanism, gear 1 (3) and gear 2 (6) are rigidly connected coaxially via connecting shaft 1 (5), with a clearance ≤0.01mm. In the side mechanism, gear 5 (14) and gear 6 (15) are coaxially arranged, with a clearance ≤0.01mm. The gear meshing backlash is controlled between 0.01-0.03mm to avoid idling errors. Bearing 1 (1), bearing 2 (13), and bearing 3 (16) reduce frictional resistance in the bottom and side transmissions, respectively, to ensure smooth rotation. This utility model guarantees molding precision: The threaded mandrel 18 is made of SKD61 material and nitrided (hardness HV≥800), while the threaded mandrel 20 is made of Cr12MoV material (hardness HRC56-58). Together with the threaded limit block 12 and the threaded limit block 22, the precise restriction of the mandrel movement direction ensures that the positioning accuracy of the threaded core reaches ±0.03mm, meeting the requirements of smooth tooth grooves and consistent helix direction for high-precision threads. This utility model optimizes space and reduces overall volume: The gear set (gear 1-3, gear 2-6, gear 3-7), rack 1-4, and threaded mandrel 1-8 are arranged along the longitudinal depth of the mold. Gear 3-7 has 16 teeth, a module of 1mm, and a pitch circle diameter of only 16mm. By utilizing the compact characteristics of gear transmission, the longitudinal space occupied is reduced.

[0027] Hydraulic cylinder 19, rack 2 17, and gear set (gear 4 11, gear 5 14, gear 6 15) are arranged in a transverse direction. The cylinder base 18 is fixed to the mold side plate to avoid longitudinal space overlap.

[0028] The two sets of mechanisms are modularly integrated into one mold cavity, which reduces the overall volume by 40% compared to multiple mold combination schemes, achieving a compact mold design.

[0029] This invention converts the linear motion of the template into the rotational motion of the threaded core through gear transmission. It utilizes the precise transmission ratio of mechanical meshing (i=0.5) to eliminate the displacement error of traditional inclined core pulling, thereby improving the positioning accuracy of the threaded core to ±0.03mm. This invention uses a rigid gear set to control the synchronization error to ≤0.1mm, ensuring that the product deformation is ≤0.074mm when multiple threads are demolded simultaneously, and meeting the dimensional tolerance requirement of ±0.03mm for the threaded hole of the slider. The stepless speed regulation characteristic of this utility model solves the impact load problem of mechanical core pulling in the prior art. Through closed-loop control of cylinder pressure, the core pulling force fluctuation is ≤5%, while the core pulling force fluctuation of the inclined top in the prior art can reach 15%-20%, thus avoiding thread profile distortion caused by uneven force. The present invention reduces the core-pulling time of the longitudinal core-pulling mechanism from approximately 3-5 seconds to ≤2 seconds through hydraulic drive. At the same time, the hydraulic system oil temperature is controlled at 40-55℃, reducing the core-pulling displacement error caused by temperature changes. This invention shortens the cycle time to 60 seconds per piece by integrating multiple core-pulling mechanisms, and improves product size consistency by 50%, demonstrating the dual benefits of "space integration + time compression". Many specific details have been set forth in the foregoing description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed above.

[0030] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A multi-directional threaded core-pulling mold, comprising a rack two (17), a hydraulic cylinder (19), a cylinder base (18), and gear five (14) and gear six (15) arranged coaxially, wherein the rack two (17) is driven and connected by the hydraulic cylinder (19), and the gear five (14) meshes with the rack two (17); characterized in that, It also includes a slider (9) and a rack (4), wherein the slider (9) is provided with a longitudinal core-pulling mechanism and a transverse core-pulling mechanism to realize axial and radial core-pulling respectively; The longitudinal core-pulling mechanism includes two threaded rods arranged side by side and vertically on the slider (9). Each threaded rod is fitted with a threaded mandrel (10). The threaded rods are threadedly connected to the threaded mandrel (10). Each threaded mandrel (10) is fixed with a gear (11). The transverse core-pulling mechanism includes two threaded rods arranged side by side on the slider (9). Each threaded rod is fitted with a threaded mandrel (8). The threaded rod is threadedly connected to the threaded mandrel (8). Each threaded mandrel (10) is fixed with a gear (7). A gear (6) is arranged between the two gears (7). The gear (6) meshes with the two gears (7). The gear (6) is arranged on the connecting shaft (5). A gear (3) is also arranged on the connecting shaft (5). The gear (3) meshes with the rack (4).

2. A multidirectional thread core-drawing mold according to claim 1, wherein Each threaded rod has a threaded limit block at the other end.

3. A multidirectional thread core-drawing mold according to claim 1 or 2, wherein The upper and lower ends of the shafts of gear five (14) and gear six (15) are respectively provided with bearing two (13) and bearing three (16).

4. A multidirectional thread core-drawing mold according to claim 3, wherein The connecting shaft (5) is provided with a bearing (1).

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