Threaded product demolding mechanism

Abstract

The embodiment of the application relates to a thread product demolding mechanism, comprising: a movable mold insert with a through hole in the axial direction, a positioning insert pin coaxially inserted into the through hole, and the positioning insert pin used to form an axial hole of the thread product; a screw core in a ring structure coaxially sleeved on the outer periphery of the movable mold insert, an inner ring surface of the screw core configured with an internal thread part, and the internal thread part used to form an external thread of the thread product; a transmission gear coaxially fixedly connected with the screw core, the transmission gear configured to receive external power and drive the screw core to rotate relative to the thread product to separate; a plunger coaxially sleeved on the outer periphery of the positioning insert pin and arranged in the through hole of the movable mold insert in the axial direction; the plunger configured to move in the axial direction to push the thread product, so that the thread product is separated from the positioning insert pin to demold. Through the cooperation of the movable mold insert, the positioning insert pin, the screw core, the transmission gear and the plunger, a two-stage demolding mechanism of rotary separation and axial pushing is constructed, and finally the overall demolding of the thread product is efficiently completed.

Description

Technical Field

[0001] This application relates to the field of demolding technology, and more particularly to a demolding mechanism for threaded products. Background Technology

[0002] In the manufacturing of plastic threaded products (such as injection-molded worm gears and threaded sleeves), injection molding has become the mainstream processing technology due to its advantages of high production efficiency, low cost, and the ability to mass-produce complex structural parts. The core feature of these products is that they need to simultaneously mold the internal shaft hole and the external thread. Therefore, the mold needs to be equipped with a special demolding mechanism to achieve efficient and non-destructive separation of the product from the mold components after molding.

[0003] Traditional multi-component linkage ejection schemes are prone to jamming due to motion coordination issues. It is necessary to design an integrated demolding logic of "rotational separation - single component axial push" to reduce the number of linkage components, reduce matching errors, ensure smooth demolding action, adapt to the mass production needs of multi-cavity molds, and avoid excessive increase in mold size. Utility Model Content

[0004] One object of this application is to provide a demolding mechanism for threaded products, which at least solves the above-mentioned problems.

[0005] To achieve the above objectives, some embodiments of this application provide a demolding mechanism for threaded products, including:

[0006] The moving mold insert has a through hole along the axial direction, and a positioning pin is coaxially inserted into the through hole. The positioning pin is used to form the shaft hole of the threaded product.

[0007] The threaded core has a ring-shaped structure and is coaxially sleeved on the outer periphery of the moving mold insert. The inner ring surface of the threaded core has an internal thread, which is used to form the external thread of the threaded product.

[0008] The transmission gear is coaxially and fixedly connected to the threaded core. The transmission gear is configured to receive external power and drive the threaded core to rotate relative to the threaded product to separate it.

[0009] The ejector sleeve is axially inserted through the through hole of the moving mold insert and coaxially sleeved around the outer periphery of the fixed mold insert; the ejector sleeve is configured to move axially to push the threaded product, thereby separating the threaded product from the positioning insert for demolding.

[0010] Compared with related technologies, the solution provided in this application constructs a two-stage demolding mechanism of rotational separation and axial pushing through the coordinated cooperation of the moving mold insert, positioning pin, threaded core, transmission gear, and ejector sleeve. The positioning pin precisely shapes the shaft hole of the threaded product, ensuring the dimensional accuracy of the shaft hole. The internal thread of the threaded core's inner ring surface stably shapes the external thread of the threaded product. The transmission gear receives external power to drive the threaded core to rotate relative to the threaded product, avoiding damage to the threaded structure caused by traditional forced demolding and achieving non-destructive separation of the threaded portion. The ejector sleeve moves axially to push the threaded product, quickly separating the threaded product from the positioning pin, ultimately efficiently completing the overall demolding of the threaded product, meeting the precise and non-destructive demolding requirements of injection-molded threaded products. Attached Figure Description

[0011] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0012] Figure 1 This is a cross-sectional schematic diagram of the demolding mechanism provided in an embodiment of this disclosure;

[0013] Figure 2 This is a schematic diagram of the demolding mechanism provided in an embodiment of this disclosure;

[0014] Figure 3 This is a partial schematic diagram of the demolding mechanism provided in an embodiment of this disclosure;

[0015] Figure 4 This is a cross-sectional schematic diagram of the moving mold insert provided in an embodiment of this disclosure;

[0016] Figure 5 This is a partial schematic diagram from another perspective of the demolding mechanism provided in an embodiment of this disclosure;

[0017] Figure 6 This is a schematic diagram of the structure of the threaded core provided in the embodiments of this disclosure;

[0018] Figure 7 This is a schematic diagram of the demolding mechanism provided in an embodiment of this disclosure from another perspective;

[0019] Figure 8 This is a partial schematic diagram of the injection mold provided in the embodiments of this disclosure;

[0020] Figure 9 This is a partial schematic diagram from another perspective of the injection mold provided in the embodiments of this disclosure.

[0021] Figure label:

[0022] 10: Moving mold insert; 101: Through hole; 1011: First hole section; 1012: Second hole section; 102: First step structure; 103: Second step structure; 20: Positioning insert; 30: Threaded core; 301: Internal thread section; 40: Transmission gear; 401: Sleeve section; 402: Gear section; 50: Sleeve; 60: Cooling insert; 601: Boss; 70: Rotating fit structure; 80: Support washer; 90: Motor; 100: Drive gear; 110: Intermediate gear; 120: Threaded product. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this disclosure described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0025] In this disclosure, the terms "upper," "lower," "inner," "middle," "outer," "front," and "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for better description of the embodiments of this disclosure and their implementations, and are not intended to limit the indicated devices, elements, or components to having a specific orientation, or to require them to be constructed and operated in a specific orientation. Furthermore, some of the aforementioned terms may be used to indicate other meanings besides orientation or positional relationship; for example, the term "upper" may in some cases indicate a dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in the embodiments of this disclosure according to the specific circumstances.

[0026] Furthermore, the terms "set up," "connect," and "fix" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this disclosure according to the specific circumstances.

[0027] Unless otherwise stated, the term "multiple" means two or more.

[0028] In this embodiment of the disclosure, the character " / " indicates that the objects before and after it are in an "or" relationship. For example, A / B means: A or B.

[0029] The term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0030] It should be noted that, unless otherwise specified, the embodiments and features described in the present disclosure can be combined with each other.

[0031] Combination Figures 1 to 9 As shown in the embodiment of this disclosure, a demolding mechanism for a threaded product includes: a movable mold insert 10, which has a through hole 101 along the axial direction, and a positioning pin 20 is coaxially inserted into the through hole 101 to form the shaft hole of the threaded product 120; a threaded core 30, which has an annular structure and is coaxially sleeved on the outer periphery of the movable mold insert 10, and the inner annular surface of the threaded core 30 has an internal thread portion 301 to form the external thread of the threaded product 120; a transmission gear 40, which is coaxially fixedly connected to the threaded core 30, and is configured to receive external power and drive the threaded core 30 to rotate relative to the threaded product 120 to separate it; and a ejector sleeve 50, which passes through the through hole 101 of the movable mold insert 10 along the axial direction and is coaxially sleeved on the outer periphery of the fixed mold pin; the ejector sleeve 50 is configured to move along the axial direction to push the threaded product 120, so that the threaded product 120 separates from the positioning pin 20 for demolding.

[0032] The demolding mechanism provided in this embodiment constructs a two-stage demolding mechanism of rotational separation and axial pushing through the coordinated operation of the moving mold insert 10, the positioning insert 20, the threaded core 30, the transmission gear 40, and the ejector sleeve 50. The positioning insert 20 precisely forms the shaft hole of the threaded product 120, ensuring the dimensional accuracy of the shaft hole. The internal thread 301 on the inner ring surface of the threaded core 30 stably forms the external thread of the threaded product 120. The transmission gear 40 receives external power to drive the threaded core 30 to rotate relative to the threaded product 120, avoiding damage to the threaded structure caused by traditional forced demolding and achieving non-destructive separation of the threaded portion. The ejector sleeve 50 moves axially to push the threaded product 120, quickly separating the threaded product 120 from the positioning insert 20, ultimately efficiently completing the overall demolding of the threaded product 120, meeting the precise and non-destructive demolding requirements of the injection-molded threaded product 120.

[0033] In this embodiment, the positioning insert 20 is coaxially inserted into the through hole 101 of the moving mold insert 10, and can be used as a dedicated forming component for the shaft hole of the threaded product 120. Through the coaxial cooperation between the positioning insert 20 and the through hole 101, the dimensional tolerance, cylindricity and coaxiality with the outer contour of the shaft hole after forming are ensured, avoiding product assembly problems caused by shaft hole misalignment. The thread core 30 is annular and the inner annular surface has an internal thread portion 301. Its coaxial sleeve relationship with the moving mold insert 10 enables the internal thread portion 301 to accurately fit the tooth profile, pitch and other parameters of the external thread of the threaded product 120, providing stable cavity constraints for the external thread, reducing defects such as missing teeth and tooth profile deformation caused by unstable cavity boundaries during injection molding, and ensuring the accuracy of the core functional structure of the threaded product 120.

[0034] The transmission gear 40 is coaxially and fixedly connected to the threaded core 30, which can convert external power (such as the drive of the motor 90) into the rotational power of the threaded core 30, causing the threaded core 30 to rotate and separate relative to the threaded product 120 along the thread direction. This rotational separation method fully conforms to the helical structure characteristics of the thread, allowing the threaded core 30 to separate from the external thread of the product without hard friction or local stress concentration, preserving the surface quality and structural integrity of the thread to the greatest extent, and meeting the functional requirements of subsequent meshing and transmission of the threaded product 120.

[0035] The ejector sleeve 50 has a through hole 101 axially inserted and is coaxially sleeved around the locating pin 20. After the threaded core 30 completes thread separation, the product can be directly pushed out by the axial movement of the ejector sleeve 50, achieving rapid separation of the product from the locating pin 20. This design eliminates the need for an additional complex multi-component linkage ejection mechanism, simplifying the demolding process. Simultaneously, the coaxial cooperation of the ejector sleeve 50, locating pin 20, and through hole 101 ensures uniform force on the product during the pushing process, preventing jamming or damage caused by product offset or tilting, and guaranteeing smooth demolding. It is particularly suitable for mass production scenarios with multi-cavity molds (such as a 16-cavity structure), allowing for the simultaneous demolding of multiple threaded products 120 through standardized "rotation and pushing" actions.

[0036] Optionally, the maximum diameter of the internal thread portion 301 is greater than the minimum diameter of the corresponding end of the moving mold insert 10, but less than the maximum diameter of the corresponding end of the moving mold insert 10.

[0037] By limiting the maximum diameter of the internal thread portion 301 to be greater than the minimum diameter of the corresponding end of the moving mold insert 10 and less than the maximum diameter of the corresponding end of the moving mold insert 10, it can be ensured that, during the rotation of the thread core 30, there is no interference between the internal thread portion 301 and the outer circumferential surface of the moving mold insert 10, avoiding component wear or rotation jamming due to structural collision, and ensuring the smoothness of the demolding process; on the other hand, this dimensional relationship can enable the internal thread portion 301 and the moving mold insert 10 to form a reasonable fit, providing stable structural support for the external thread forming of the threaded product 120, ensuring the forming accuracy of the external thread, and avoiding defects such as material shortage or deformation of the external thread due to improper dimensional fit.

[0038] Optionally, one end of the sleeve 50 near the threaded product 120 is located within the through hole 101 of the moving mold insert 10 to form the unthreaded shaft end of the threaded product 120.

[0039] By placing one end of the ejector sleeve 50 near the threaded product 120 within the through hole 101 of the moving mold insert 10, the unthreaded shaft end of the threaded product 120 can be directly formed using the mating structure between this end of the ejector sleeve 50 and the through hole 101 of the moving mold insert 10. This eliminates the need for additional specialized forming components, simplifying the overall mold structure, reducing the number of parts, and ensuring the coaxiality and dimensional accuracy of the unthreaded shaft end with the product body. It also avoids shaft end deviations caused by multi-part assembly, thus improving the overall forming quality of the threaded product 120.

[0040] Optionally, the moving mold insert 10, the threaded core 30, the ejector sleeve 50, and the positioning pin 20 enclose the injection cavity of the threaded product 120 for injecting molten raw materials to form the threaded product 120.

[0041] The injection cavity of the threaded product 120 is enclosed by the moving mold insert 10, the threaded core 30, the ejector sleeve 50, and the positioning insert 20, forming a closed and precise material molding space. This injection cavity can perfectly match the shape and internal structure of the threaded product 120, ensuring that the molten material can be fully filled into each molding area after injection, avoiding insufficient or excessive filling of material.

[0042] Optionally, the transmission gear 40 is interference-fitted onto the outer periphery of the threaded core 30, or is coaxially fixed to the threaded core 30 via a key connection, so that the transmission gear 40 and the threaded core 30 rotate synchronously.

[0043] The transmission gear 40 is coaxially fixed to the threaded core 30 via an interference fit or a key connection, enabling synchronous rotation of both. The interference fit ensures no relative rotational clearance between the transmission gear 40 and the threaded core 30, resulting in direct and efficient power transmission and avoiding energy loss during power transmission. The key connection facilitates the disassembly and maintenance of the transmission gear 40 and the threaded core 30, while also ensuring sufficient transmission accuracy, guaranteeing that external power is accurately transmitted to the threaded core 30 through the transmission gear 40, driving the threaded core 30 to rotate stably.

[0044] Optionally, the outer peripheral surface of the moving mold insert 10 is constructed with a first step structure 102, the end face of the first step structure 102 abutting against the end face of the threaded core 30 to axially limit the installation position of the threaded core 30.

[0045] A first step structure 102 is constructed on the outer peripheral surface of the moving mold insert 10, and its end face abuts against the end face of the threaded core 30. This allows for precise axial positioning of the threaded core 30. It can quickly determine the assembly position of the threaded core 30 on the moving mold insert 10, improving assembly efficiency. At the same time, it prevents axial movement of the threaded core 30 during installation or use, ensuring the relative position stability of the threaded core 30 with other components (such as the positioning insert 20 and the ejector sleeve 50). This ensures the structural stability of the threaded product 120 during molding and demolding, and avoids molding defects or demolding failures of the threaded product 120 due to the positional deviation of the threaded core 30.

[0046] Optionally, the outer peripheral surface of the moving mold insert 10 is also constructed with a second step structure 103, the end face of the second step structure 103 abutting against the end face of the transmission gear 40 to axially limit the installation position of the transmission gear 40; wherein, the second step structure 103 is located on the side of the first step structure 102 away from the threaded product 120.

[0047] A second step structure 103 is provided on the outer peripheral surface of the moving mold insert 10, located on the side of the first step structure 102 opposite to the threaded product 120. Its end face abuts against the end face of the transmission gear 40, which can axially limit the transmission gear 40. The second step structure 103 can cooperate with the first step structure 102 to axially position the threaded core 30 and the transmission gear 40 respectively, clarifying the assembly sequence and positional relationship of the two on the moving mold insert 10, ensuring the coaxiality of the transmission gear 40 and the threaded core 30, avoiding loosening of the connection between the transmission gear 40 and the threaded core 30 or transmission deviation due to axial displacement, and ensuring the stability of power transmission.

[0048] Optionally, the outer peripheral surface of the moving mold insert 10 is inclined towards its own axis from the first step structure 102 to the end facing the threaded product 120, forming a tapered surface; the inner ring surface of the threaded core 30 is a tapered inner ring surface adapted to the tapered surface, so that the threaded core 30 fits against the outer peripheral surface of the moving mold insert 10.

[0049] The conical surfaces of the moving mold insert 10 and the threaded core 30 fit together, achieving a tighter contact through the self-centering effect of the conical surface compared to the traditional cylindrical surface fit, significantly reducing the gap between them. This tight fit effectively prevents molten material from seeping out from the mating surface of the moving mold insert 10 and the threaded core 30 during injection molding, avoiding defects such as flash and burrs caused by material leakage.

[0050] During assembly, the conical inner ring surface of the threaded core 30 automatically aligns with the conical surface of the moving mold insert 10, ensuring precise alignment of their axes and avoiding the "eccentricity" problem that easily occurs with traditional cylindrical surface mating. This high-precision coaxiality ensures the stability of the relative position between the internal thread portion 301 of the inner ring surface of the threaded core 30 and the outer circumferential surface of the moving mold insert 10, thereby guaranteeing the symmetry of the thread profile and the uniformity of the pitch of the external thread of the threaded product 120, and avoiding asymmetrical defects such as excessive thickness or insufficient material on one side of the thread caused by coaxiality deviation.

[0051] Furthermore, the "wedge-shaped" constraint structure formed by the tapered surface mating can simultaneously position the threaded core 30 in both the axial and radial directions: in the axial direction, the inclination angle of the tapered surface can limit the axial movement of the threaded core 30; in the radial direction, the mutual support of the mating surfaces can prevent the threaded core 30 from radially shifting during demolding. This bidirectional positioning effect ensures that the threaded core 30 maintains a stable trajectory when receiving power from the transmission gear 40 and driving the internal thread part 301 to rotate and separate relative to the product, avoiding thread scraping and demolding jamming caused by the offset of the threaded core 30, and ensuring the smoothness of the demolding process.

[0052] Compared to traditional line or point contact mating on planar or cylindrical surfaces, the surface contact structure formed by tapered surface mating increases the contact area between the moving mold insert 10 and the threaded core 30, dispersing the frictional force generated during relative movement (such as the rotation of the threaded core 30 during demolding). The increased contact area reduces frictional stress per unit area, decreases wear on the component surface, and avoids problems such as increased clearance and decreased molding accuracy caused by excessive localized wear.

[0053] Optionally, it also includes a cooling insert 60, coaxially sleeved on the outer periphery of the transmission gear 40, for cooling the threaded product 120. The cooling insert 60 has a cooling channel inside, which is used to introduce a cooling medium to cool the transmission gear 40, the threaded core 30 and the threaded product 120 in the injection cavity through heat conduction, thereby shortening the molding cycle.

[0054] The cooling insert 60 is coaxially sleeved on the outer periphery of the transmission gear 40. After the cooling medium is introduced into its internal cooling channel, the transmission gear 40, the thread core 30 and the threaded product 120 in the injection cavity can be cooled sequentially by heat conduction. This can quickly reduce the temperature of the threaded product 120, shorten the product molding cycle and improve production efficiency. At the same time, uniform cooling can reduce the internal stress of the product caused by the temperature gradient and avoid defects such as warping and deformation.

[0055] Optionally, the transmission gear 40 includes an integrated sleeve portion 401 and a gear portion 402, with the gear portion 402 protruding circumferentially along the outer peripheral surface of the sleeve portion 401; the cooling insert 60 is sleeved on the outer periphery of the sleeve portion 401, and a rotating engagement structure 70 is provided between the cooling insert 60 and the sleeve portion 401. The rotating engagement structure 70 is used to allow the sleeve portion 401 to rotate freely relative to the cooling insert 60, while restricting the axial movement of the sleeve portion 401.

[0056] The transmission gear 40 adopts an integrated sleeve portion 401 and gear portion 402 structure. The cooling insert 60 is sleeved on the outer periphery of the sleeve portion 401 and connected by a rotating fit structure 70. The integrated structure enhances the overall strength and rigidity of the transmission gear 40, ensuring structural stability during power transmission and preventing component breakage or deformation. The rotating fit structure 70 allows the sleeve portion 401 to rotate freely relative to the cooling insert 60, ensuring the smoothness of the transmission gear 40 driving the threaded core 30 to rotate and demold. At the same time, it restricts the axial movement of the sleeve portion 401, ensuring the relative position stability between the transmission gear 40 and the cooling insert 60, and preventing axial displacement from affecting the cooling effect or power transmission accuracy.

[0057] Optionally, the cooling insert 60 extends radially toward its own axis from the edge away from the gear portion 402 to form a boss 601. The rotating engagement structure 70 is sleeved on the outer periphery of the sleeve portion 401, with one end of the rotating engagement structure 70 abutting against the end face of the boss 601 and the other end abutting against the end face of the gear portion 402 to axially limit the rotating engagement structure 70.

[0058] The cooling insert 60 extends from the edge away from the gear portion 402 to form a boss 601. Its end face forms an axial limiting space with the end face of the gear portion 402. The two ends of the rotating fit structure 70 abut against the end face of the boss 601 and the end face of the gear portion 402, respectively, which can directly limit the axial installation position of the rotating fit structure 70 on the outer periphery of the sleeve portion 401. Without the need for additional bolts, snap rings or other auxiliary positioning parts, the assembly of the rotating fit structure 70 can be achieved by the structure itself, ensuring the coaxiality of the inner ring of the rotating fit structure 70 (such as a bearing) with the sleeve portion 401 and the outer ring with the cooling insert 60, and avoiding uneven fit clearance caused by assembly misalignment.

[0059] During the operation of the demolding mechanism, the transmission gear 40 drives the sleeve portion 401 to rotate, and the rotating mating structure 70 needs to withstand radial loads and axial impact forces. The bidirectional abutment between the boss 601 and the gear portion 402 can form a rigid axial constraint, completely limiting the axial movement space of the rotating mating structure 70 along the sleeve portion 401, and preventing the mating relationship with the sleeve portion 401 and the cooling insert 60 from loosening due to axial displacement. This stable limiting effect ensures that the rotating mating structure 70 is always in the optimal working position, reduces vibration and noise during rotation, ensures smooth power transmission, and avoids jamming of the demolding action caused by axial movement.

[0060] Optionally, the rotating fit structure 70 includes at least one set of bearings. The inner ring of the bearing is interference-fitted with the sleeve portion 401, and the outer ring is interference-fitted with the inner circumferential surface of the cooling insert 60, to reduce the rotational friction between the sleeve portion 401 and the cooling insert 60. The rolling friction characteristics of the bearing can significantly reduce the rotational frictional resistance between the sleeve portion 401 and the cooling insert 60, reduce component wear, and extend service life. The interference fit ensures that the bearing is firmly connected to the sleeve portion 401 and the cooling insert 60, avoids relative sliding, ensures rotational accuracy, and makes the rotation of the threaded core 30 more stable and smooth when the transmission gear 40 drives it, thus improving the stability and reliability of the demolding process.

[0061] Optionally, it also includes a support shim 80, coaxially sleeved on the outer periphery of the end of the transmission gear 40 away from the sleeve portion 401, for axial support of the transmission gear 40. In this way, the axial force on the end of the transmission gear 40 can be distributed, avoiding deformation or damage to the transmission gear 40 due to concentrated axial force; at the same time, the support shim 80 can keep the transmission gear 40 in a stable axial mounting posture, ensuring the meshing accuracy of the transmission gear 40 with other components (such as the intermediate gear 110, drive mechanism), avoiding poor meshing due to tilting of the transmission gear 40, and ensuring the stability and accuracy of power transmission.

[0062] Optionally, the through hole 101 includes a first hole section 1011 and a second hole section 1012 connected sequentially along the axial direction. The second hole section 1012 is located on the side of the first hole section 1011 away from the threaded product 120, and the diameter of the second hole section 1012 is larger than the diameter of the first hole section 1011. The inner ring surface of the second hole section 1012 is clearance-fitted with the outer circumferential surface of the ejector sleeve 50 to allow the ejector sleeve 50 to move smoothly along the axial direction while preventing molten material from entering the second hole section 1012. The clearance fit reduces the frictional resistance between the ejector sleeve 50 and the inner ring surface of the second hole section 1012 when the ejector sleeve 50 moves along the axial direction, ensuring smooth movement of the ejector sleeve 50 when pushing the product, avoiding jamming, and improving demolding efficiency. At the same time, the larger diameter of the second hole section 1012 than the first hole section 1011 can form a stepped structure, preventing molten material from entering the second hole section 1012, avoiding solidification of the material in the second hole section 1012 that could cause jamming or damage to the ejector sleeve 50, ensuring normal mold operation, and reducing the workload of cleaning the mold.

[0063] Optionally, it also includes a drive mechanism that meshes with the transmission gear 40 to output torque and drive the transmission gear 40 to rotate, thereby causing the threaded core 30 to rotate around its own axis.

[0064] The drive mechanism meshes with the transmission gear 40 and outputs torque to drive its rotation, providing a stable and controllable power source for the rotation and demolding of the threaded core 30. It eliminates the need for external manual operation or other unstable power sources, ensuring the automation and consistency of the demolding process. The drive mechanism can adjust its output torque and speed according to actual demolding requirements, adapting to the demolding requirements of different thread specifications 120, ensuring an efficient and stable demolding process.

[0065] Optionally, the drive mechanism includes: a motor 90; a drive gear 100, which is connected to the output shaft of the motor 90, and the drive gear 100 is connected to the transmission gear 40 so as to drive the transmission gear 40 to rotate synchronously under the drive of the motor 90.

[0066] The motor 90 provides a stable power source, and the drive gear 100 serves as an intermediate transmission component to realize the power transmission between the motor 90 and the transmission gear 40 (thread core 30). Compared with direct drive, the drive gear 100 can reduce or increase speed (according to the speed of the motor 90 and the required speed of the thread core 30), ensuring that the thread core 30 rotates at the optimal speed, avoiding excessively high speed leading to excessively fast thread separation (resulting in damage to the threaded product 120) or excessively low speed (prolonging the demolding time). At the same time, the gear transmission method has the advantages of high transmission efficiency and high precision, ensuring the stability and accuracy of power transmission.

[0067] Optionally, the drive mechanism further includes at least one intermediate gear 110, which is simultaneously meshed with the drive gear 100 and the transmission gear 40, or simultaneously meshed with two transmission gears 40, to adjust the transmission ratio or the synchronous rotation of multiple sets of threaded cores 30.

[0068] When multiple intermediate gears 110 are provided, the driving gear 100 meshes with the first intermediate gear 110, and the last intermediate gear 110 meshes with the transmission gear 40, forming a multi-stage gear transmission structure.

[0069] The intermediate gear 110 can flexibly adjust the transmission ratio of the drive mechanism, so that the rotation speed of the thread core 30 can be precisely matched with the demolding requirements of different thread products 120 (such as products with larger thread pitch require lower rotation speed to ensure complete thread separation), thereby improving the versatility of the mold. At the same time, for multiple sets of thread cores 30 (such as a 1-outlet 16-cavity structure), the intermediate gear 110 can realize the synchronous drive of multiple sets of transmission gears 40, ensuring the consistency of the demolding process of multi-cavity products and improving the stability and efficiency of mass production.

[0070] For example, when using a 16-cavity design (i.e., each cavity is equipped with the above-mentioned demolding mechanism), the 16 cavities are arranged in a 4x4 matrix. The transmission gears 40 on the outside of the 16 sets of threaded cores 30 are all meshed with an intermediate gear 110. The intermediate gear 110 then meshes with the drive gear 100 (connected to the output shaft of the motor 90), forming a linkage structure of "motor 90 - drive gear 100 - intermediate gear 110 - 16 transmission gears 40", ensuring that the 16 sets of threaded cores 30 rotate synchronously.

[0071] When the drive mechanism is started, the motor 90 drives the 16 sets of threaded cores 30 to rotate synchronously in the opposite direction (opposite to the direction of the internal thread) through gear linkage; then the 16 sets of ejector sleeves 50 push the threaded product 120 to separate from the positioning insert 20, thus completing the demolding.

[0072] For example, the demolding process of an injection mold is executed in an orderly manner in four stages: "mold opening - screw core 30 rotation separation - ejector sleeve 50 axial push - component reset". The specific process is as follows:

[0073] When molten raw material is injected into the injection cavity enclosed by the moving mold insert 10, the threaded core 30, the ejector sleeve 50, and the positioning pin 20, it is cooled and solidified by the cooling medium (such as cooling water) introduced through the cooling channel in the cooling insert 60, forming a threaded product 120 (such as a plastic worm gear) with external threads, a shaft hole, and a non-threaded shaft end. Then, the mold starts the mold opening action: the fixed mold and the moving mold separate along the parting surface, and the relevant components on the fixed mold side (such as the fixed mold fixing plate) move away from the moving mold side. At this time, the threaded product 120 is still sleeved on the outer periphery of the positioning pin 20 through the shaft hole, and the external thread engages with the internal thread portion 301 of the inner ring surface of the threaded core 30.

[0074] When the moving mold side drive mechanism (such as motor 90) is started, the output shaft of motor 90 drives the drive gear 100 to rotate. The drive gear 100 transmits power to the transmission gear 40, which is coaxially fixed with the threaded core 30, through the intermediate gear 110 (set as needed, used to adjust the transmission ratio or synchronize multi-cavity action).

[0075] After receiving power, the transmission gear 40 drives the integrated threaded core 30 to rotate around its own axis (the rotation direction is consistent with the external thread direction of the threaded product 120); at this time, the conical inner ring surface of the threaded core 30 fits with the conical surface of the outer periphery of the moving mold insert 10. The conical fit structure provides a stable rotation guide for the threaded core 30 and avoids radial offset during rotation.

[0076] When the threaded core 30 rotates, the internal thread portion 301 of its inner ring surface moves relative to the threaded product 120 along the helical trajectory of the external thread of the threaded product 120, gradually releasing the meshing constraint with the external thread; at the same time, the rotating mating structure 70 (such as a bearing) ensures that there is no axial movement of the threaded core 30 during rotation under the axial limit of the boss 601 of the cooling insert 60 and the gear portion 402 of the transmission gear 40, so that the separation action is smooth and controllable until the threaded core 30 is completely disengaged from the external thread of the threaded product 120. At this time, the product is only connected to the positioning insert 20 through the shaft hole.

[0077] After the threaded core 30 completes the thread separation, the ejector system on the moving mold side (such as ejector plate, ejector rod) drives the ejector sleeve 50 to move axially along the through hole 101 of the moving mold insert 10; the clearance fit between the ejector sleeve 50 and the second hole section 1012 of the through hole 101 ensures that there is no jamming during its movement and avoids the impact of residual injection molding material on the smoothness of the operation.

[0078] The sleeve 50, located near the end of the threaded product 120 (within the through hole 101 of the moving mold insert 10, which was previously used to form unthreaded shaft ends), directly pushes the unthreaded shaft end of the threaded product 120. The axial thrust overcomes the frictional force between the threaded product 120 and the positioning pin 20, causing the threaded product 120 to move along the axis of the positioning pin 20 and gradually detach from the positioning pin 20. When the sleeve 50 moves to the preset stroke (usually slightly greater than the length of the shaft hole of the threaded product 120), the product is completely separated from the positioning pin 20 and falls into the mold unloading area or is picked up by the robot.

[0079] After the threaded product 120 is removed, the drive mechanism reverses its rotation, driving the transmission gear 40 to rotate in the opposite direction through the drive gear 100 and the intermediate gear 110. This causes the threaded core 30 to rotate in the opposite direction and return to its axial position along the tapered surface of the moving mold insert 10, until the end face of the threaded core 30 abuts against the end face of the first step structure 102 of the moving mold insert 10, restoring it to its initial injection position.

[0080] The ejector system reverses its action, causing the ejector sleeve 50 to retract axially along the through hole 101 back to its initial position. Its end near the threaded product 120 retracts back into the through hole 101 of the moving mold insert 10, reserving cavity space for the next injection molding.

[0081] After the threaded core 30 and the ejector sleeve 50 are reset, the mold starts the mold closing action, the fixed mold and the moving mold close again, and the cooling insert 60, the positioning pin 20 and other components are restored to the assembly state before injection molding, waiting for the next round of molten raw material injection to start a new production cycle.

[0082] The foregoing description and accompanying drawings fully illustrate embodiments of the present disclosure to enable those skilled in the art to practice them. Other embodiments may include structural and other changes. The embodiments represent only possible variations. Individual components and functions are optional unless explicitly required, and the order of operation may vary. Parts and features of some embodiments may be included or substituted for parts and features of other embodiments. Embodiments of the present disclosure are not limited to the structures described above and shown in the accompanying drawings, and various modifications and changes may be made without departing from its scope. The scope of the present disclosure is limited only by the appended claims, and the foregoing embodiments should be considered exemplary and non-limiting.

Claims

1. A demolding mechanism for a threaded product, characterized in that, include: The moving mold insert has a through hole along the axial direction, and a positioning pin is coaxially inserted into the through hole. The positioning pin is used to form the shaft hole of the threaded product. The threaded core has a ring-shaped structure and is coaxially sleeved on the outer periphery of the moving mold insert. The inner ring surface of the threaded core has an internal thread, which is used to form the external thread of the threaded product. The transmission gear is coaxially and fixedly connected to the threaded core. The transmission gear is configured to receive external power and drive the threaded core to rotate relative to the threaded product to separate it. The ejector sleeve is axially inserted through the through hole of the moving mold insert and coaxially sleeved around the outer periphery of the fixed mold insert; the ejector sleeve is configured to move axially to push the threaded product, thereby separating the threaded product from the positioning insert for demolding.

2. The demolding mechanism according to claim 1, characterized in that, The outer peripheral surface of the moving mold insert has a first step structure, and the end face of the first step structure abuts against the end face of the threaded core to axially limit the installation position of the threaded core.

3. The demolding mechanism according to claim 2, characterized in that, The outer peripheral surface of the moving mold insert is also constructed with a second step structure. The end face of the second step structure abuts against the end face of the transmission gear to axially limit the installation position of the transmission gear. The second step structure is located on the side of the first step structure that is away from the threaded product.

4. The demolding mechanism according to claim 2, characterized in that, The outer peripheral surface of the moving mold insert slopes towards its own axis from the first step structure to the end facing the threaded product, forming a tapered surface; The inner ring surface of the threaded core is a tapered inner ring surface adapted to the tapered surface, so that the threaded core fits against the outer peripheral surface of the moving mold insert.

5. The demolding mechanism according to claim 1, characterized in that, Also includes: Cooling inserts are coaxially fitted around the outer circumference of the transmission gear to cool threaded products.

6. The demolding mechanism according to claim 5, characterized in that, The transmission gear includes an integrated sleeve portion and a gear portion, with the gear portion protruding circumferentially along the outer peripheral surface of the sleeve portion; The cooling insert is fitted around the outer periphery of the sleeve portion, and a rotating fit structure is provided between the cooling insert and the sleeve portion. The rotating fit structure is used to allow the sleeve portion to rotate freely relative to the cooling insert, while restricting the axial movement of the sleeve portion.

7. The demolding mechanism according to claim 6, characterized in that, The cooling insert extends radially toward its own axis from the edge away from the gear part to form a boss, and the rotating fit structure is sleeved on the outer periphery of the sleeve part; In this configuration, one end of the rotating fit structure abuts against the end face of the boss, and the other end abuts against the end face of the gear part, thereby axially limiting the rotating fit structure.

8. The demolding mechanism according to claim 6, characterized in that, Also includes: A support shim is coaxially sleeved on the outer periphery of the end of the transmission gear away from the sleeve portion, and is used to axially support the transmission gear.

9. The demolding mechanism according to any one of claims 1 to 8, characterized in that, It also includes a drive mechanism, which meshes with the transmission gear to output torque and drive the transmission gear to rotate, thereby causing the threaded core to rotate around its own axis; wherein, the drive mechanism includes: Electric motor; The drive gear is connected to the output shaft of the motor and is also connected to the transmission gear so that the transmission gear can rotate synchronously under the drive of the motor.

10. The demolding mechanism according to claim 9, characterized in that, The drive mechanism also includes at least one intermediate gear, which meshes with both the drive gear and the transmission gear, or with two transmission gears simultaneously, to adjust the transmission ratio or the synchronous rotation of multiple sets of threaded cores. When multiple intermediate gears are set, the driving gear meshes with the first intermediate gear, and the last intermediate gear meshes with the transmission gear, forming a multi-stage gear transmission structure.

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