Double-layer twisting mechanism and double-layer twisting mold

Abstract

The invention relates to a double-layer thread twisting mechanism and a double-layer thread twisting mould, the double-layer thread twisting mechanism comprises an inner thread twisting body, and the upper end of the inner thread twisting body is provided with threads for thread twisting; threads used for twisting teeth are arranged at the upper end of the outer twisting tooth body, the outer twisting tooth body is hollow in the axial direction, and the inner twisting tooth body is located on the inner side of the outer twisting tooth body and is coaxial with the outer twisting tooth body; the inner support body is fixedly arranged between the outer twisted tooth body and the inner twisted tooth body; the first beryllium copper sleeve is fixedly connected to the inner side of the outer twisted tooth body and abuts against the inner supporting body; and the second beryllium copper sleeve is fixedly connected to the outer side of the inner twisted tooth body and abuts against the inner supporting body, the inner twisted tooth body and the outer twisted tooth body are separated through the first beryllium copper sleeve, the second beryllium copper sleeve and the inner supporting body, damage caused by contact clamping of the two twisted tooth bodies in the twisted tooth process is avoided, and the twisted tooth production efficiency and reliability are both considered.

Description

Technical Field

[0001] The present application relates to the field of bottle cap processing molds, and in particular to a double-layer thread twisting mechanism and a double-layer thread twisting mold. Background Art

[0002] Many cosmetic bottles need to be installed with an integrated inner and outer cap, the inner cap is used for sealing, and the outer cap is used for decoration. Most of the existing bottle caps are made using molds, and common bottle caps are processed with internal threads so that the bottle caps can be screwed onto the bottle body, while cosmetic bottle caps need to have double-layer threads. In the prior art, in the process of manufacturing bottle caps by injection molding with a double-layer threading mold, two threading bodies are required to thread the inner and outer bottle caps respectively. If the inner and outer bottle caps are threaded separately, two threading processes are required, and the production efficiency is low; if the inner and outer bottle caps are threaded at the same time, the two threading bodies are prone to get stuck and damage the mold, and the reliability is poor. Summary of the invention

[0003] In order to solve the problem that the existing double-layer twisting thread mold cannot take into account both production efficiency and production reliability, the present application provides a double-layer twisting thread mechanism and a double-layer twisting thread mold, which can perform double-layer twisting threads at the same time and avoid jamming and wear of the two twisting thread bodies, taking into account both production efficiency and production reliability.

[0004] In the first aspect, the double-layer thread twisting mechanism provided by the present application adopts the following technical solution: A double-layer thread twisting mechanism, comprising: An internal thread body, wherein the upper end of the internal thread has a thread for threading; An external twisted tooth body, wherein the upper end of the external twisted tooth body has a thread for twisting the teeth, the external twisted tooth body is axially hollow, and the internal twisted tooth body is located inside the external twisted tooth body and is coaxially arranged with the external twisted tooth body; An inner support body, the inner support body being fixedly disposed between the outer twisted tooth body and the inner twisted tooth body; A first beryllium copper sleeve, which is fixedly connected to the inner side of the outer thread body and abuts against the inner support body; and A second beryllium copper sleeve is fixedly connected to the outer side of the inner threaded body and abuts against the inner support body.

[0005] By adopting the above technical solution, the inner thread body and the outer thread body are separated by the first beryllium copper sleeve, the second beryllium copper sleeve and the inner support body, so as to avoid the two thread bodies from contacting and getting stuck during the threading process and causing damage, thereby improving the reliability of threading production. In addition, the design of the beryllium copper sleeve reduces the influence of friction on the rotation of the thread body, and the beryllium copper sleeve can be directly removed and replaced after being worn, which is convenient, fast and low-cost.

[0006] In the second aspect, the double-layer twisted tooth mold provided by the present application adopts the following technical solution: A double-layer twisted tooth mold comprises an upper mold, a lower mold and the double-layer twisted tooth mechanism as described above, wherein the lower mold and the upper mold are detachably connected by fasteners, and when the lower mold and the upper mold are connected, the lower mold and the upper mold enclose a product space, the upper ends of the inner twisted tooth body and the outer twisted tooth body are both located in the product space, the outer twisted tooth body is rotatably mounted on the lower mold, the lower end of the inner twisted tooth body extends to the outside of the outer twisted tooth body and is rotatably connected to the lower mold, and the inner support body is fixedly connected to the lower mold.

[0007] By adopting the above technical solution, a double-layer thread twisting mechanism is applied to the thread twisting mold, so that the parts of the inner thread twisting body and the outer thread twisting body used for thread twisting are located in the product space, and the screw thread can be twisted out during the injection molding process, thereby improving production efficiency.

[0008] Optionally, a first gear is fixedly connected to the lower end of the outer threaded tooth body, a second gear is fixedly provided at the lower end of the inner threaded tooth body, and a first opening and a second opening are provided on the lower mold, the first opening is used for passing a rack that can mesh with the first gear, and the second opening is used for passing a rack that can mesh with the second gear.

[0009] By adopting the above technical solution, the rotation of the inner and outer twisted tooth bodies is realized through gear rack transmission, the transmission structure is simple and reliable, and the inner and outer twisted tooth bodies are rotated by independent gear rack transmission structures, which can meet more twisted tooth requirements.

[0010] Optionally, a ball retaining sleeve is connected between the inner twisted tooth body and the lower die, and a ball retaining sleeve is connected between the outer twisted tooth body and the lower die.

[0011] By adopting the above technical solution and arranging the ball retaining sleeve, the rotation of the inner and outer twisted tooth bodies can be smoother and more stable, thereby improving the reliability of the structure.

[0012] Optionally, the lower die is slidably connected to two or more wedge blocks, the wedge blocks are circumferentially distributed with the rotation axis of the external twisted tooth body as the central axis and all the wedge blocks form a closed ring, the wedge blocks are slidably connected to the lower die and a first elastic member is connected between the wedge blocks and the lower die, and the first elastic member has an elastic tendency to drive the wedge blocks to move away from the central axis; Among them, the side of the wedge block facing the central axis is located in the product space and has a convexity or a concaveness, and the side of the wedge block away from the central axis is a first inclined surface, which is inclined outward from top to bottom and abuts against the upper mold.

[0013] By adopting the above technical solution, a sliding wedge block is provided, so that when the upper mold is installed on the lower mold, the wedge block is pushed to move to one side of the product space, so that the local convex or concave shape of the wedge block constitutes a part of the side wall of the product space. When demolding, after the upper mold is separated from the lower mold, the wedge block moves under the action of the first elastic member and breaks away from contact with the molded product part, thereby avoiding interference with the product part and damaging the product part during the demolding process.

[0014] Optionally, a moving part and more than two clamping blocks are installed in the upper die, the clamping blocks are distributed circumferentially with the rotation axis of the external twisted tooth body as the center line and all the clamping blocks form a closed ring, the clamping block is slidably connected to the upper die and a second elastic member is connected between the clamping block and the upper die, the second elastic member has an elastic tendency to drive the clamping block to move away from the central axis, and the clamping block is in conflict with a side of the wedge block facing the central axis; The movable member is located inside the closed ring formed by the clamping block and the side of the movable member has a second inclined surface for contacting the clamping block, the second inclined surface is inclined outward from top to bottom, the lower end surface of the movable member is located in the product space, the movable member is slidably installed in the upper mold along the up and down directions and a third elastic member is connected to the upper mold, the third elastic member has an elastic tendency to drive the movable member to move upward.

[0015] By adopting the above technical scheme, during the connection process between the upper mold and the lower mold, the upper mold pushes the wedge block to move, the wedge block pushes the clamping block to move, and the clamping block pushes the moving part to move. On the one hand, the fit between the wedge block and the clamping block and between the clamping block and the moving block is ensured to avoid material leakage during the product injection molding process. On the other hand, when the upper mold and the lower mold are separated during the demolding process, the wedge block, the clamping block and the moving block move under the action of the corresponding elastic parts, thereby quickly breaking away from contact with the product parts and avoiding interference with the product parts during demolding and causing damage to the product parts.

[0016] Optionally, an injection port is provided in the upper mold, and an internal channel is provided in the movable member so as to pass through the upper and lower parts. The lower end of the internal channel is connected to the product space, and the upper end of the internal channel is connected to the injection port.

[0017] By adopting the above technical solution, the injection port is connected with the internal channel in the moving part, so that the material is injected into the product space from top to bottom, thereby ensuring the injection efficiency.

[0018] Optionally, a telescopic connecting tube is connected between the upper end of the movable member and the upper mold, one end of the connecting tube is connected to the injection port, and the other end is connected to the internal channel.

[0019] By adopting the above technical solution, since the movable part moves up and down, a telescopic connecting pipe is used to connect the injection port and the internal channel, thereby improving the injection reliability.

[0020] Optionally, the connecting pipe is a corrugated pipe.

[0021] By adopting the above technical solution, a bellows-type connecting pipe is used, which has low cost and can be cut to length according to needs, making it more convenient to use.

[0022] Optionally, the lower end of the movable member abuts against the upper end of the inner threaded tooth body.

[0023] By adopting the above technical solution, the lower end of the moving part abuts against the upper end of the inner threaded body, which can be used for injection molding of annular hollow products with a high degree of customization.

[0024] In summary, the present application includes at least one of the following beneficial technical effects: The beryllium copper sleeve is used to isolate the two threading bodies to prevent the two threading bodies from contacting each other during the threading process, thereby preventing them from getting stuck and improving production reliability while ensuring production efficiency. The beryllium copper sleeve is easy to replace after being worn, which is convenient, fast and low cost; During the connection process of the upper die and the lower die, the wedge block is pushed to move by the upper die, and then the clamping block is pushed to move by the wedge block, and then the moving block is pushed to move by the clamping block, to ensure that the lower end of the moving block can abut against the upper end of the inner threaded tooth body to meet the shape requirements of the product space. In addition, during the demolding process, after the upper die and the lower die are separated, the wedge block, the clamping block and the moving block are moved and reset to separate from the product under the action of the elastic part, thereby avoiding damage to the product during demolding. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a three-dimensional structural diagram of a double-layer thread-twisting mechanism.

[0026] Figure 2 yes Figure 1 Explosion diagram.

[0027] Figure 3 It is a three-dimensional structural schematic diagram of a double-layer twisted tooth mold.

[0028] Figure 4 yes Figure 3 A schematic cross-sectional view of .

[0029] Figure 5 yes Figure 4 A is an enlarged schematic diagram.

[0030] Figure 6 yes Figure 5 A magnified schematic diagram of B.

[0031] Figure 7 It is a schematic diagram of the three-dimensional structure of the product produced by injection molding using a double-layer twisted tooth mold from two perspectives.

[0032] Figure 8 It is a side view cutaway diagram of a product part.

[0033] Explanation of the reference numerals: 1. first template; 2. second template; 3. third template; 4. fourth template; 5. fifth template; 6. sixth template; 7. seventh template; 8. eighth template; 9. ninth template; 10. tenth template; 11. eleventh template; 12. avoidance space; 13. third elastic member; 14. connecting pipe; 15. moving member; 16. internal passage; 17. through space; 18. second elastic member; 20. outer support body; 21. outer threaded body; 22. first beryllium copper sleeve; 23. inner support body; 24. second Beryllium copper sleeve; 25, ball retaining sleeve; 26, first gear; 27, second gear; 28, internal threaded body; 29, clamping block; 31, second inclined surface; 33, product space; 34, wedge block; 35, first elastic member; 38, molding surface; 39, first inclined surface; 100, upper mold; 200, lower mold; 300, first opening; 400, second opening; 500, injection port; 600, fastener; 700, product part; 701, identification surface; 702, external thread surface; 703, internal thread surface; 800, threading mechanism. DETAILED DESCRIPTION

[0034] The present application is further described in detail below in conjunction with the accompanying drawings.

[0035] Combined with Figure 1 and attached Figure 2As shown, the present invention discloses a double-layer threading mechanism 800, including an inner threading body 28, an outer threading body 21, an inner support body 23, a first beryllium copper sleeve 22 and a second beryllium copper sleeve 24. Specifically, the upper end of the outer threading body 21 has a thread for threading, and the outer threading body 21 is axially hollow for accommodating the inner threading body 28. The inner threading body 28 is located on the inner side of the outer threading body 21 and is coaxially arranged with the outer threading body 21, and the upper end of the inner threading body 28 also has a thread for threading. Through the rotation of the outer threading body 21 and the inner threading body 28, they can be used to respectively twist out the outer and inner threadings on the bottle cap product. In actual use, the outer threading body 21 and the inner threading body 28 can be driven to rotate simultaneously, so that the outer and inner threadings can be twisted out simultaneously, thereby improving production efficiency. Of course, it is also possible to only drive the outer thread body 21 to rotate to twist out the outer thread, or only drive the inner thread body 28 to rotate to twist out the inner thread, so as to meet more thread requirements. The inner support body 23 is arranged between the outer thread body 21 and the inner thread body 28, and is used to separate the outer thread body 21 and the inner thread body 28. It is possible to avoid contact, jamming and wear of the two thread bodies during simultaneous rotation, thereby ensuring the thread efficiency and improving the reliability of thread production. In addition, the inner support body 23 is fixedly arranged to prevent the inner support body 23 from rotating with the outer thread body 21 or the inner thread body 28. The first beryllium copper sleeve 22 is fixedly connected to the inner side of the outer thread body 21 and abuts against the inner support body 23, and the second beryllium copper sleeve 24 is fixedly connected to the outer side of the inner thread body 28 and abuts against the inner support body 23. Beryllium copper material is a cheap, widely used elastic and wear-resistant material. The beryllium copper sleeve is set between the outer thread body 21 and the inner support and between the inner thread body 28 and the inner support as a wear and tear part, which reduces the wear of the inner thread body 28 and the outer thread body 21, is easy and quick to replace, and reduces production costs.

[0036] Combined with Figure 1 To Attachment Figure 6 As shown, the present invention further discloses a double-layer twisted tooth mold, including an upper mold 100, a lower mold 200 and the above-mentioned double-layer twisted tooth mechanism 800. Specifically, the present application provides the following embodiments.

[0037] In the embodiment of the present application, the lower mold 200 and the upper mold 100 in the double-layer thread-twisting mold are detachably connected by a fastener 600, and the lower mold 200 and the upper mold 100 enclose a product space 33 when the lower mold 200 and the upper mold 100 are connected. The upper ends of the inner thread body 28 and the outer thread body 21 in the thread-twisting mechanism 800 are both located in the product space 33, and the screw thread can be twisted out during the injection molding process by rotating the inner thread body 28 and the outer thread body 21, thereby improving production efficiency. The outer thread body 21 and the inner thread body 28 are both rotatably mounted on the lower mold 200, and the lower end of the inner thread body 28 extends to the outside of the outer thread body 21 and then rotatably mounted with the lower mold 200, and the inner support body 23 is fixedly connected with the lower mold 200. It should be noted that in this embodiment, the upper end of the outer twisted tooth body 21, the upper end of the inner twisted tooth body 28 and the upper end of the support body all extend into the product space 33, that is, the upper end of the outer twisted tooth body 21, the upper end of the inner twisted tooth body 28 and the upper end of the support body serve as part of the side wall of the product space 33.

[0038] Specifically, in this embodiment, the upper mold 100 is composed of a first mold plate 1, a second mold plate 2, a third mold plate 3 and a fourth mold plate 4 from top to bottom, and the lower mold 200 is composed of a fifth mold plate 5, a sixth mold plate 6, a seventh mold plate 7, an eighth mold plate 8, a ninth mold plate 9, a tenth mold plate 10 and an eleventh mold plate 11 from top to bottom. Four fastening bolts are used between the upper mold 100 and the lower mold 200 for detachable installation.

[0039] In a further configuration, the lower end of the outer twisted tooth body 21 is fixedly connected to the first gear 26, the lower end of the inner twisted tooth body 28 is fixedly provided with the second gear 27, the sixth template 6 in the lower mold 200 is provided with a first opening 300, and the seventh template 7 in the lower mold 200 is provided with a second opening 400. The first opening 300 is used to penetrate a rack (not shown) that can mesh with the first gear 26, and the second opening 400 is used to penetrate a rack that can mesh with the second gear 27. The rotation of the inner twisted tooth body 28 and the outer twisted tooth body 21 is achieved by gear and rack transmission. In actual application, the rack for meshing the first gear 26 and the rack for meshing the second gear 27 can run synchronously, so that the rotation of the first gear 26 and the second gear 27 are synchronized, so that the inner twisted tooth body 28 and the outer twisted tooth body 21 can be twisted at the same time. Improve production efficiency. In addition, the rotational driving method of the threading body includes but is not limited to the gear rack transmission method in this embodiment. The gear rack transmission method has the advantages of simple structure and reliable transmission, and the two sets of gear rack transmissions can also be independently driven to realize the separate threading processing of the outer threading body 21 and the inner threading body 28 to meet more production needs.

[0040] In a further configuration, a ball retaining sleeve 25 is connected between the inner twisted tooth body 28 and the lower die 200 and between the outer twisted tooth body 21 and the lower die 200, so that the rotation of the inner twisted tooth body 28 and the outer twisted tooth body 21 is smoother and more stable.

[0041] The present application also provides more preferred embodiments in terms of demoulding.

[0042] Specifically, there are more than two wedge blocks 34 slidably connected to the lower die 200, the wedge blocks 34 are distributed circumferentially with the rotation axis of the outer threaded body 21 as the central axis, and all the wedge blocks 34 form a closed ring, the wedge blocks 34 are slidably connected to the lower die 200, and a first elastic member 35 is connected between the wedge blocks 34 and the lower die 200, and the first elastic member 35 has an elastic tendency to drive the wedge blocks 34 to move away from the central axis. Among them, the side of the wedge block 34 facing the central axis is located in the product space 33 and has a convexity or concave, and the side of the wedge block 34 away from the central axis is a first inclined surface 39, which is inclined outward from top to bottom and abuts against the upper die 100.

[0043] In this embodiment, the outer support body 20 is fixedly provided in the lower mold 200, and the wedge block 34 is slidably installed on the outer support body 20. Two wedge blocks 34 are provided and are symmetrically distributed on the left and right. The two wedge blocks 34 are both in the shape of a 180° ring. When the two wedge blocks 34 are attached, they just form a closed circular ring. The end surface of the wedge block 34 facing the central axis is located in the product space 33, that is, the end surface of the wedge block 34 facing the central axis is a part of the side wall of the product space 33.

[0044] In addition, a convex or concave shape is provided on the end surface of the wedge block 34 facing the central axis, and a concave or convex shape is also formed on the product during injection molding, that is, the end surface of the wedge block 34 facing the central axis can also be called a molding surface 38. In this embodiment, the convex or concave shape is a logo text shape for marking the product name, so there is no need for subsequent engraving process.

[0045] When the upper mold 100 approaches the lower mold 200 from top to bottom and is connected to the lower mold 200, the fourth mold plate 4 in the upper mold 100 contacts the first inclined surface 39 of the wedge block 34 and pushes the wedge block 34 to move toward the central axis until the two wedge blocks 34 contact each other, at which time the upper mold 100 and the lower mold 200 are just connected. During the demoulding process, due to the convex or concave setting on the molding surface 38, there will be interference between the wedge block 34 and the injection molded product in the vertical direction. At this time, if the product is directly demoulded in the vertical direction, it is easy to cause product damage.

[0046] In this embodiment, the upper mold 100 is separated upward from the lower mold 200 during demolding. Due to the setting of the first elastic member 35, the wedge block 34 will move away from the central axis after being released from the restriction of the fourth mold plate 4, thereby eliminating the interference of the wedge block 34 on the product in the vertical direction, thereby facilitating the demolding and removal of the product.

[0047] In a further configuration, a moving part 15 and more than two clamping blocks 29 are installed in the upper mold 100. The clamping blocks 29 are distributed circumferentially with the rotation axis of the outer threaded body 21 as the center line, and all the clamping blocks 29 are surrounded by a closed ring. The clamping blocks 29 are slidably connected to the upper mold 100 and are connected to the upper mold 100 by a second elastic member 18. The second elastic member 18 has an elastic tendency to drive the clamping blocks 29 to move away from the central axis. The clamping blocks 29 are in conflict with a side of the wedge block 34 facing the central axis. In this embodiment, a through space 17 is provided in the fourth template 4 of the upper mold 100, which is connected from top to bottom, so as to install the clamping blocks 29. Two clamping blocks 29 are provided and are symmetrically distributed on the left and right. Both clamping blocks 29 are in a 180° ring shape. When the two clamping blocks 29 are attached, they just form a closed circular ring. The clamping block 29 on the left is against the wedge block 34 on the left, and the clamping block 29 on the right is against the wedge block 34 on the right. The moving block is located inside the closed ring surrounded by the clamp block 29 and the side of the moving member 15 has a second inclined surface 31 for contacting the clamp block 29, and the second inclined surface 31 is inclined outward from top to bottom. The lower end surface of the moving member 15 is located in the product space 33, and the moving member 15 is slidably installed in the upper mold 100 along the up and down directions and is connected to the upper mold 100 by a third elastic member 13, and the third elastic member 13 has an elastic tendency to drive the moving member 15 to move upward. It should be noted that the clamp block 29 and part of the moving member 15 are also located in the product space 33, that is, the clamp block 29 and part of the moving member 15 are part of the side wall of the product space 33.

[0048] Specifically, an escape space 12 for avoiding the movement of the moving member 15 is opened in the third template 3. During the connection process between the upper mold 100 and the lower mold 200, the fourth template 4 in the upper mold 100 pushes the wedge block 34 to move, the wedge block 34 pushes the clamping block 29 to move, and the clamping block 29 pushes the moving member 15 to move. On the one hand, the fit between the wedge block 34 and the clamping block 29 and between the clamping block 29 and the moving block is ensured, that is, the sealing of the side wall of the product space 33 is ensured, and material leakage is avoided during the product injection molding process. On the other hand, when the upper mold 100 and the lower mold 200 are separated during the demoulding process, the wedge block 34, the clamping block 29 and the moving block move under the action of the corresponding elastic member, thereby quickly breaking away from contact with the product part 700, avoiding interference with the product part 700 during demoulding and causing damage to the product part 700.

[0049] The present application also provides more preferred embodiments in terms of injection.

[0050] Specifically, an injection port 500 is provided in the upper mold 100, and an internal channel 16 is provided in the moving part 15 so as to pass through the moving part 15 from top to bottom. The lower end of the internal channel 16 is connected to the product space 33, and the upper end of the internal channel 16 is connected to the injection port 500. In this embodiment, an injection port 500 is provided on the first template 1, and the raw material for injection molding flows from top to bottom into the internal channel 16 of the moving part 15, and then flows from the internal channel 16 into the product space 33, thereby ensuring the injection molding efficiency.

[0051] In a further configuration, since the moving member 15 may move up and down during use, a telescopic connecting tube 14 is connected between the upper end of the moving member 15 and the upper mold 100, and one end of the connecting tube 14 is connected to the injection port 500, and the other end is connected to the internal channel 16 to adapt to the up and down displacement of the moving member 15 and ensure the reliability of injection. Specifically, the connecting tube 14 is a bellows, which is cheap and low in cost, and the bellows is easy to cut to length, making it more convenient to use.

[0052] The present application also provides more preferred embodiments in terms of molding.

[0053] Specifically, the lower end of the moving member 15 abuts against the upper end of the inner thread body 28, so that the product space 33 is in a ring shape, and the final injection molded product 700 is also in a ring-shaped hollow shape, as shown in the attached Figure 7 , Attachment Figure 8 The product 700 has a surface 701 formed by the forming surface 38 of the wedge block 34 , an external thread surface 702 formed by the external thread body 21 , and an internal thread surface 703 formed by the internal thread body 28 .

[0054] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A double-layer thread twisting mechanism, characterized in that: include: An internal threaded body (28), wherein the upper end of the internal threaded body (28) has a thread for threading; An external twisted tooth body (21), the upper end of the external twisted tooth body (21) having a thread for twisting the teeth, the external twisted tooth body (21) being axially hollow, and the internal twisted tooth body (28) being located inside the external twisted tooth body (21) and being coaxially arranged with the external twisted tooth body (21); An inner support body (23), the inner support body (23) being fixedly disposed between the outer twisted tooth body (21) and the inner twisted tooth body (28); A first beryllium copper sleeve (22), the first beryllium copper sleeve (22) being fixedly connected to the inner side of the outer threaded body (21) and abutting against the inner support body (23); as well as A second beryllium copper sleeve (24), the second beryllium copper sleeve (24) is fixedly connected to the outside of the inner threaded body (28) and abuts against the inner support body (23).

2. A double-layer twisted tooth mold, characterized in that: The invention comprises an upper die (100), a lower die (200) and a double-layer twisted tooth mechanism (800) as claimed in claim 1, wherein the lower die (200) and the upper die (100) are detachably connected via a fastener (600); when the lower die (200) and the upper die (100) are connected, the lower die (200) and the upper die (100) enclose a product space (33); the upper ends of the inner twisted tooth body (28) and the outer twisted tooth body (21) are both located in the product space (33); the outer twisted tooth body (21) is rotatably mounted on the lower die (200); the lower end of the inner twisted tooth body (28) extends to the outside of the outer twisted tooth body (21) and is rotatably connected to the lower die (200); and the inner support body (23) is fixedly connected to the lower die (200).

3. The double-layer twisted tooth mold according to claim 2, characterized in that: The lower end of the outer threaded body (21) is fixedly connected to a first gear (26), the lower end of the inner threaded body (28) is fixedly provided with a second gear (27), and the lower die (200) is provided with a first opening (300) and a second opening (400), the first opening (300) being used for passing a rack capable of meshing with the first gear (26), and the second opening (400) being used for passing a rack capable of meshing with the second gear (27).

4. The double-layer twisted tooth mold according to claim 2, characterized in that: A ball retaining sleeve (25) is connected between the inner twisted tooth body (28) and the lower die (200), and a ball retaining sleeve (25) is connected between the outer twisted tooth body (21) and the lower die (200).

5. The double-layer twisted tooth mold according to any one of claims 2 to 4, characterized in that: The lower die (200) is slidably connected to two or more wedge blocks (34), the wedge blocks (34) are circumferentially distributed with the rotation axis of the external threaded tooth body (21) as the central axis and all the wedge blocks (34) form a closed ring, the wedge blocks (34) are slidably connected to the lower die (200) and a first elastic member (35) is connected between the wedge blocks (34) and the lower die (200), and the first elastic member (35) has an elastic tendency to drive the wedge blocks (34) to move away from the central axis; The side surface of the wedge block (34) facing the central axis is located in the product space (33) and has a protrusion or a concave portion, and the side surface of the wedge block (34) away from the central axis is a first inclined surface (39), which is inclined outward from top to bottom and abuts against the upper mold (100).

6. The double-layer twisted tooth mold according to claim 5, characterized in that: The upper die (100) is provided with a moving part (15) and more than two clamping blocks (29), the clamping blocks (29) are distributed circumferentially with the rotation axis of the external threaded body (21) as the center line and all the clamping blocks (29) form a closed ring, the clamping blocks (29) are slidably connected to the upper die (100) and a second elastic member (18) is connected between the clamping blocks (29) and the upper die (100), the second elastic member (18) having an elastic tendency to drive the clamping blocks (29) to move away from the central axis, and the clamping blocks (29) are in contact with a side surface of the wedge block (34) facing the central axis; The movable member (15) is located inside the closed ring formed by the clamping block (29), and the side of the movable member (15) has a second inclined surface (31) for contacting the clamping block (29), the second inclined surface (31) is inclined outward from top to bottom, the lower end surface of the movable member (15) is located in the product space (33), the movable member (15) is slidably installed in the upper mold (100) along the up-down direction, and a third elastic member (13) is connected between the movable member (15) and the upper mold (100), and the third elastic member (13) has an elastic tendency to drive the movable member (15) to move upward.

7. The double-layer twisted tooth mold according to claim 6, characterized in that: The upper mold (100) is provided with an injection port (500), and the movable member (15) is provided with an internal channel (16) which passes through the upper and lower parts, wherein the lower end of the internal channel (16) is connected to the product space (33) and the upper end of the internal channel (16) is connected to the injection port (500).

8. The double-layer twisted tooth mold according to claim 7, characterized in that: A telescopic connecting tube (14) is connected between the upper end of the moving member (15) and the upper mold (100); one end of the connecting tube (14) is connected to the injection port (500), and the other end is connected to the internal channel (16).

9. The double-layer twisted tooth mold according to claim 8, characterized in that: The connecting pipe (14) is a corrugated pipe.

10. The double-layer twisted tooth mold according to claim 6, characterized in that: The lower end of the moving member (15) abuts against the upper end of the inner threaded body (28).

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