Screw hole lateral core-pulling mold structure

Abstract

A screw hole lateral core-pulling mold structure comprises a core-pulling assembly and a mold provided with a cavity, one side of the cavity is provided with a core-pulling face, the core-pulling assembly comprises a fixing frame, a motor, a main rotating shaft, a first secondary shaft, a core-pulling block and a forming shaft, the motor is installed on the fixing frame, the fixing frame is provided with a first threaded sleeve, and the main rotating shaft is rotationally connected to the fixing frame and driven by the motor to rotate; the core-pulling block is connected to the mold in a sliding mode, the first secondary shaft comprises a threaded connection end in threaded connection to the first threaded sleeve and an adapting end rotationally connected to the core-pulling block, and the forming shaft comprises an adapting end rotationally connected to the core-pulling block and a screw rod end extending towards the core-pulling face; torque transmission is achieved between the main rotating shaft and the first secondary shaft and between the first secondary shaft and the forming shaft through transmission wheels. According to the scheme, the core pulling block is combined with the forming shaft, so that a screw hole structure is machined while a product is subjected to injection molding, the one-time demolding function is achieved, the machining efficiency is effectively improved, the machining quality of a screw hole in the product is stable and reliable, and good practicability is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of moulds, and in particular to a screw hole lateral core pulling mould structure. Background Art

[0002] Molds are a type of processing equipment widely used in modern manufacturing. They are applicable to automobiles, electronics, home appliances, etc., and cover a variety of types such as injection molding, die casting, and stamping. For injection molds, the main working principle is to form a cavity structure between the upper mold base and the lower mold base. When the upper mold base and the lower mold base are closed, hot melt raw materials are injected into the cavity. After the raw materials are cooled and formed, the upper mold base and the lower mold base are separated from each other to achieve demolding, and the finished product can be taken out of the cavity.

[0003] However, with the continuous development of market demand, the product structure to be processed by the mold is becoming more and more complex. For example, some products need to have screw hole structures processed at the side. The conventional method of the prior art is to set a core puller at the corresponding position of the cavity, process a through hole at the side of the product by core puller, and then perform secondary processing on the product to process the through hole into a screw hole. Obviously, this method requires two processing steps, which is inefficient, and the product needs to be re-clamped during the secondary processing, which may lead to unstable quality of screw hole processing. Summary of the invention

[0004] The purpose of the present invention is to solve the problem in the prior art that when processing the screw hole structure at the side position of the product, it needs to be processed twice, which is inefficient, and the product needs to be re-clamped during the secondary processing, which may lead to unstable screw hole processing quality.

[0005] In order to solve the above problems, the present invention provides a screw hole side core pulling mold structure, including a core pulling assembly and a mold with a cavity, one side of the cavity is provided with a core pulling surface, the core pulling assembly includes a fixed frame, a motor, a main rotating shaft, a first shaft, a core pulling block and a forming shaft, the fixed frame is arranged adjacent to the core pulling surface, the motor is installed on the fixed frame, the fixed frame is provided with a first screw sleeve with an axis perpendicular to the core pulling surface, the main rotating shaft is rotatably connected to the fixed frame and driven to rotate by the motor, and the core pulling block is slidably connected to the mold in a direction perpendicular to the core pulling surface to achieve the core pulling surface Open and close, the first shaft is located on the side of the core pulling block facing away from the core pulling surface, the first shaft includes a threaded end threaded to the first screw sleeve and a transfer end rotatably connected to the core pulling block, and the transfer end of the first shaft is axially fixed relative to the core pulling block; the forming shaft is located on the side of the core pulling block facing the core pulling surface, the forming shaft includes a transfer end rotatably connected to the core pulling block and a screw end extending toward the core pulling surface, and the transfer end of the forming shaft is axially fixed relative to the core pulling block, and torque transmission is achieved between the main rotating shaft and the first shaft, and between the first shaft and the forming shaft through a transmission wheel.

[0006] The above scheme designs the structure of the core pulling component. When the mold is closed, the motor drives the first shaft to rotate in the forward direction through the main shaft. Due to the threaded connection between the first shaft and the first screw sleeve, the first shaft will produce axial displacement and gradually approach the core pulling surface. At this time, the core pulling block will be driven by the first shaft to approach the core pulling surface until the core pulling surface is closed. Then hot-melt raw material is injected into the cavity, and a screw hole will be processed at the position of the screw end of the core pulling surface corresponding to the molding shaft; when the raw material in the cavity is cooled and formed, the motor drives the first shaft to rotate in the opposite direction through the main shaft, and the first shaft will gradually move away from the core pulling surface. At this time, on the one hand, the core pulling block is driven by the first shaft to move away from the core pulling surface to achieve demolding, and on the other hand, the molding shaft will be driven by the first shaft to rotate, so that the screw end of the molding shaft is gradually and synchronously screwed out of the screw hole of the product. Compared with the existing technology, the advantages of the above scheme include: 1. Simplified processing technology, through the core pulling block combined with the forming shaft during product injection molding, the screw hole structure can be processed without multiple processing; 2. Efficient demoulding is achieved, and the motor drives the rotation of the active shaft, the first shaft, and the forming shaft to achieve the release of the forming shaft relative to the screw hole structure; 3. High quality reliability, avoiding the problem of re-clamping during secondary processing of the product in the existing technology, resulting in unstable screw hole processing quality.

[0007] In an improved solution, a main gear is provided at the output end of the main rotating shaft, a first main drive gear is provided on one side of the threaded end of the first shaft and a first drive gear is provided on one side of the adapter end, a driven gear is provided on one side of the adapter end of the forming shaft, the tooth thickness of the first main drive gear is smaller than that of the main gear, the first main drive gear is meshed with the main gear and can slide axially relative to the main gear, and the first drive gear is meshed with the driven gear, so that the transmission between the main rotating shaft and the first shaft, and between the first shaft and the forming shaft is stable and reliable, and because the tooth thickness of the first main drive gear is smaller than that of the main gear, when the first shaft moves axially, the first main drive gear can always mesh with the main gear to achieve transmission.

[0008] In an improved solution, the core pulling assembly also includes a secondary shaft, the fixed frame is provided with a second screw sleeve parallel to and spaced apart from the first screw sleeve, the secondary shaft includes a threaded end threaded to the second screw sleeve and a transfer end rotatably connected to the core pulling block, a second main drive gear is provided on one side of the threaded end of the secondary shaft, the tooth thickness of the second main drive gear is smaller than that of the main gear, the second main drive gear is meshed with the main gear and can slide axially relative to the main gear, the first main drive gear and the second main drive gear are respectively located on both sides of the main gear, and the transfer end of the first shaft and the transfer end of the second shaft are at equal distances relative to the center of the core pulling block. After adopting the above structure, when the motor drives the main shaft to rotate, since the first main drive gear and the second main drive gear are respectively located on both sides of the main gear, the main shaft can be balanced in force, avoiding the deflection torque that exists when there is only the first main drive gear; at the same time, due to the threaded end of the secondary shaft and the threaded action of the second screw sleeve, when the first shaft and the second shaft rotate synchronously, the two will also produce axial movement synchronously. Since the adapter end of the first shaft and the adapter end of the second shaft are at an equal distance relative to the center of the core pulling block, they jointly drive the core pulling block to approach or move away from the core pulling surface, so that the movement of the core pulling block is more stable and accurate, ensuring the product processing quality.

[0009] In an improved solution, a mounting hole is provided on the side of the core pulling block facing the core pulling surface, the adapter end of the molding shaft is rotatably inserted into the mounting hole, and the molding sleeve is provided with a sealing ring flush with the hole opening of the mounting hole, and the sealing ring is used to close the gap between the molding shaft and the mounting hole, thereby preventing the hot-melt material in the cavity from entering the mounting hole.

[0010] In an improved solution, the outer diameter of the sealing ring is equal to the hole diameter of the mounting hole, and the outer peripheral wall of the sealing ring is in sliding contact with the hole wall of the mounting hole, thereby ensuring the sealing effect of the sealing ring on the mounting hole.

[0011] In an improved solution, the sealing ring is made of beryllium copper, which has better wear resistance.

[0012] In an improved solution, a cooling pipeline is provided in the interior of the molding shaft along the axial direction, so as to achieve rapid cooling of the molding shaft during demoulding.

[0013] In an improved solution, the cooling pipeline includes a straight first hole section extending from the adapter end of the molding shaft to the screw end and a spiral second hole section extending from the screw end of the molding shaft to the adapter end. The first hole section is bent 180 degrees at the screw end to form a tubular hole and then extends toward the adapter end until it penetrates, so that the coolant can enter from the middle of the adapter end of the molding shaft and diffuse outward after flowing to the screw end, thereby achieving better cooling of the outer peripheral wall of the molding shaft, and then flows out from the adapter end along the tubular hole to achieve circulating cooling.

[0014] In an improved solution, there are two forming shafts, so that two screw holes can be processed on the product in one operation to meet different product needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is an overall schematic diagram of a screw hole side core pulling mold structure; Figure 2 It is a schematic diagram of a screw hole side core pulling mold structure with the upper side of the mold and the upper side of the fixing frame hidden; Figure 3 A screw hole side core pulling die structure Figure 2 The schematic diagram after the core extraction block is hidden on the basis; Figure 4 A screw hole side core pulling die structure Figure 3 Schematic diagram after the upper side of the cavity is hidden.

[0016] Description of reference numerals: 1. Mold; 11. Cavity; 12. Core-pulling surface; 2. Fixing frame; 21. First screw sleeve; 22. Second screw sleeve; 3. Motor; 4. Main shaft; 41. Main gear; 5. First primary shaft; 51. First main drive gear; 52. First primary drive gear; 6. Second secondary shaft; 61. Second main drive gear; 7. Core-pulling block; 8. Forming shaft; 81. Screw end; 82. Driven gear; 83. Sealing ring. DETAILED DESCRIPTION

[0017] It should be understood by those skilled in the art that the following embodiments are only used to explain the technical principles of the embodiments of the present application and are not intended to limit the protection scope of the embodiments of the present application. Those skilled in the art may adjust them as needed to adapt to specific application scenarios.

[0018] In the description of the following embodiments, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of this application can be understood according to specific circumstances.

[0019] In the embodiments of the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0020] The present application is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] See also Figure 1-Figure 4 , a screw hole side core pulling mold structure provided by an embodiment of the present invention comprises a core pulling assembly and a mold 1 provided with a cavity 11, a core pulling surface 12 is provided on one side of the cavity 11, the core pulling assembly comprises a fixed frame 2, a motor 3, a main rotating shaft 4, a first shaft 5, a core pulling block 7 and a forming shaft 8, the fixed frame 2 is arranged adjacent to the core pulling surface 12, the motor 3 is installed on the fixed frame 2, the fixed frame 2 is provided with a first screw sleeve 21 with an axis perpendicular to the core pulling surface 12, the main rotating shaft 4 is rotatably connected to the fixed frame 2 and driven to rotate by the motor 3, and the core pulling block 7 is slidably connected to the mold 1 in a direction perpendicular to the core pulling surface 12 to realize rotation of the core pulling surface 12 is opened and closed, the first shaft 5 is located on the side of the core pulling block 7 facing away from the core pulling surface 12, the first shaft 5 includes a threaded end threaded to the first screw sleeve 21 and a transfer end rotatably connected to the core pulling block 7, and the transfer end of the first shaft 5 is axially fixed relative to the core pulling block 7; the forming shaft 8 is located on the side of the core pulling block 7 facing the core pulling surface 12, the forming shaft 8 includes a transfer end rotatably connected to the core pulling block 7 and a screw end 81 extending toward the core pulling surface 12, and the transfer end of the forming shaft 8 is axially fixed relative to the core pulling block 7; torque transmission is achieved between the main rotating shaft 4 and the first shaft 5, and between the first shaft 5 and the forming shaft 8 through a transmission wheel.

[0022] like Figure 1 As shown, in the present embodiment, the fixing frame 2 is arranged on the right side of the mold 1 in a fixed manner relative to the mold 1, the core pulling surface 12 is located on the right side of the cavity 11, and the shape of the core pulling block 7 is adapted to the core pulling surface 12. When the core pulling block 7 slides toward the cavity 11 in a direction perpendicular to the core pulling surface 12, the cavity 11 can be closed, which corresponds to the mold closing state; when the core pulling block 7 slides away from the cavity 11 in a direction perpendicular to the core pulling surface 12, the cavity 11 can be opened, which corresponds to the demolding state.

[0023] When the mold 1 is closed, the motor 3 drives the first shaft 5 to rotate in the forward direction through the main shaft 4. Due to the threaded connection between the first shaft 5 and the first screw sleeve 21, the first shaft 5 will produce axial displacement and gradually approach the core pulling surface 12. At this time, the core pulling block 7 will be driven by the first shaft 5 to approach the core pulling surface 12 until the core pulling surface 12 is closed, and then the hot melt raw material is injected into the cavity 11, and a screw hole will be processed at the position of the screw end 81 of the forming shaft 8 on the core pulling surface 12; when the raw material in the cavity 11 is cooled and formed, the motor 3 drives the first shaft 5 to rotate in the opposite direction through the main shaft 4, and the first shaft 5 will gradually move away from the core pulling surface 12. At this time, on the one hand, the core pulling block 7 is driven by the first shaft 5 to move away from the core pulling surface 12 to achieve demolding, and on the other hand, the forming shaft 8 will be driven by the first shaft 5 to rotate, so that the screw end 81 of the forming shaft 8 is gradually and synchronously screwed out of the screw hole of the product. Compared with the prior art, the advantages of the above scheme include: simplified processing technology, through the core pulling block 7 combined with the forming shaft 8 during product injection molding, the screw hole structure can be processed without multiple processing; efficient demolding is achieved, and the motor 3 drives the rotation of the active shaft 4, the first shaft 5, and the forming shaft 8 to achieve the release of the forming shaft 8 relative to the screw hole structure; high quality reliability, avoiding the problem of re-clamping during secondary processing of the product in the prior art, resulting in unstable screw hole processing quality.

[0024] Combination Figure 2 and Figure 3 As shown, regarding the specific implementation form of torque transmission between the main rotating shaft 4 and the first secondary shaft 5, and between the first secondary shaft 5 and the forming shaft 8, both are achieved through the transmission wheel. In this embodiment, a main gear 41 is provided at the output end of the main rotating shaft 4, a first main driving gear 51 is provided on one side of the threaded end of the first secondary shaft 5, and a first driving gear 52 is provided on one side of the adapter end, and a driven gear 82 is provided on one side of the adapter end of the forming shaft 8. The tooth thickness of the first main driving gear 51 is smaller than that of the main gear 41. The first main driving gear 51 is meshed with the main gear 41 and can slide axially relative to the main gear 41. The first driving gear 52 is meshed with the driven gear 82, so that the transmission between the main rotating shaft 4 and the first secondary shaft 5, and between the first secondary shaft 5 and the forming shaft 8 is stable and reliable. Since the tooth thickness of the first main driving gear 51 is smaller than that of the main gear 41, when the first secondary shaft 5 moves axially, the first main driving gear 51 can always mesh with the main gear 41 to achieve transmission. It should be understood that, according to the required transmission ratio, gear sets can be additionally provided between the main rotating shaft 4 and the first secondary shaft 5, and between the first secondary shaft 5 and the forming shaft 8; for example, in the present embodiment, the main gear 41 is designed to be rotatably connected to the fixed frame 2, and a pinion is provided on the main rotating shaft 4, which meshes with the main gear 41, thereby realizing the function of the main rotating shaft 4 driving the main gear 41 to rotate; the first secondary shaft 5 and the forming shaft 8 can also be provided with gear sets to change the transmission ratio as needed, and the principles are similar, which will not be repeated here.

[0025] As an improvement to this embodiment, Figure 2As shown, the core pulling assembly also includes a secondary shaft 6, the fixed frame 2 is provided with a second screw sleeve 22 which is parallel to and spaced from the first screw sleeve 21, the secondary shaft 6 includes a threaded end threaded to the second screw sleeve 22 and a transfer end rotatably connected to the core pulling block 7, a second main drive gear 61 is provided on one side of the threaded end of the secondary shaft 6, the tooth thickness of the second main drive gear 61 is smaller than the main gear 41, the second main drive gear 61 is meshed with the main gear 41 and can slide axially relative to the main gear 41, the first main drive gear 51 and the second main drive gear 61 are respectively located on both sides of the main gear 41, and the transfer end of the first shaft 5 and the transfer end of the second shaft 6 are at equal distances relative to the center of the core pulling block 7. After adopting the above structure, when the motor 3 drives the main shaft 4 to rotate, since the first main drive gear 51 and the second main drive gear 61 are respectively located on both sides of the main gear 41, the main shaft 4 can be balanced in force, avoiding the deflection torque that exists when there is only the first main drive gear 51; at the same time, due to the threaded end of the secondary shaft 6 and the threaded action of the second screw sleeve 22, when the first shaft 5 and the second shaft 6 rotate synchronously, the two will also produce axial movement synchronously. Since the adapter end of the first shaft 5 and the adapter end of the second shaft 6 are at an equal distance relative to the center of the core pulling block 7, they jointly drive the core pulling block 7 to approach or move away from the core pulling surface 12, so that the movement of the core pulling block 7 is more stable and accurate, ensuring the product processing quality. In addition, regarding the rotational connection of the transfer end of the first shaft 5 and the transfer end of the second shaft 6 relative to the core pulling block 7, rotation holes can be respectively opened at both ends of the core pulling block 7 on the side facing away from the core pulling surface 12, the two rotation holes are equal in width center relative to the core pulling block 7, the transfer end of the first shaft 5 and the transfer end of the second shaft 6 are respectively provided with bearings, and the transfer end of the first shaft 5 and the transfer end of the second shaft 6 are rotationally connected to the two rotation holes through bearings. In addition, "the transfer end of the first shaft 5 and the transfer end of the second shaft 6 are equal in distance relative to the center of the core pulling block 7" means that they are approximately equal.

[0026] In this embodiment, a mounting hole (not shown in the figure) is provided on the side of the core pulling block 7 facing the core pulling surface 12, and the adapter end of the forming shaft 8 is rotatably plugged into the mounting hole through a bearing. The forming shaft 8 is sleeved with a sealing ring 83 flush with the opening of the mounting hole, and the sealing ring 83 is used to close the gap between the forming shaft 8 and the mounting hole, thereby preventing the hot-melt raw material in the cavity 11 from entering the mounting hole. The outer diameter of the sealing ring 83 is equal to the aperture of the mounting hole, and the outer peripheral wall of the sealing ring 83 is in sliding contact with the hole wall of the mounting hole, thereby ensuring the sealing effect of the sealing ring 83 on the mounting hole. The material of the sealing ring 83 is preferably beryllium copper, so that it has good wear resistance; of course, it can be other materials, and this design is not limited to this.

[0027] As another improvement to this embodiment, a cooling pipeline is provided inside the molding shaft 8 along the axial direction. Since the friction between the screw end 81 of the molding shaft 8 and the screw hole of the product is relatively large, by providing a cooling pipeline inside the molding shaft 8, the molding shaft 8 is cooled before the core-pulling block during demoulding, so that the screw end 81 of the molding shaft 8 cools and shrinks and separates from the screw hole of the product, reducing the friction resistance between the screw end 81 of the molding shaft 8 and the screw hole of the product. The cooling pipeline can be a simple straight hole extending from the middle of the adapter end of the molding shaft 8 toward the screw end 81, and of course it can also be other forms, which is not limited by this design.

[0028] In addition, in this embodiment, there can be two forming shafts 8, which are parallel and spaced apart. Both forming shafts 8 are driven by the primary shaft 5 to rotate, so that two screw holes can be processed on the product in one operation to meet different product needs.

[0029] It should be noted that, in the description of the present application, the terms "inside", "outside", etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and does not indicate or imply that the device or component must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present application; all directional indications (such as up, down, left, right, front, back, inside, and outside) are only used to explain the relative positional relationship, movement, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0030] In the description of the present application, the description with reference to the terms "one embodiment", "some embodiments", "in the present embodiment", "specific example", or "some examples" etc. means that the specific features, mechanisms, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, mechanisms, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0031] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A screw hole side core pulling mold structure, characterized in that: The invention comprises a core pulling assembly and a mold (1) provided with a mold cavity (11), wherein one side of the mold cavity (11) is provided with a core pulling surface (12), the core pulling assembly comprises a fixed frame (2), a motor (3), a main rotating shaft (4), a first shaft (5), a core pulling block (7) and a molding shaft (8), the fixed frame (2) is arranged adjacent to the core pulling surface (12), the motor (3) is installed on the fixed frame (2), the fixed frame (2) is provided with a first screw sleeve (21) whose axis is perpendicular to the core pulling surface (12), the main rotating shaft (4) is rotatably connected to the fixed frame (2) and driven to rotate by the motor (3), the core pulling block (7) is slidably connected to the mold (1) in a direction perpendicular to the core pulling surface (12) to realize the opening and closing of the core pulling surface (12), and the first screw sleeve (21) is provided with a first screw sleeve (21) whose axis is perpendicular to the core pulling surface (12). The secondary shaft (5) is located on the side of the core pulling block (7) facing away from the core pulling surface (12); the primary shaft (5) comprises a threaded end threadedly connected to the first screw sleeve (21) and a transfer end rotatably connected to the core pulling block (7); and the transfer end of the primary shaft (5) is axially fixed relative to the core pulling block (7); the forming shaft (8) is located on the side of the core pulling block (7) facing the core pulling surface (12); the forming shaft (8) comprises a transfer end rotatably connected to the core pulling block (7) and a screw end (81) extending toward the core pulling surface (12); and the transfer end of the forming shaft (8) is axially fixed relative to the core pulling block (7); torque transmission is achieved between the main rotating shaft (4) and the primary shaft (5), and between the primary shaft (5) and the forming shaft (8) via transmission wheels.

2. The screw hole side core pulling mold structure according to claim 1, characterized in that: The output end of the main rotating shaft (4) is provided with a main gear (41), the first primary drive gear (51) is provided on one side of the threaded end of the first primary shaft (5) and the first primary drive gear (52) is provided on one side of the transfer end, the transfer end of the forming shaft (8) is provided with a driven gear (82), the tooth thickness of the first primary drive gear (51) is smaller than that of the main gear (41), the first primary drive gear (51) is meshed with the main gear (41) and can slide axially relative to the main gear (41), and the first primary drive gear (52) is meshed with the driven gear (82).

3. The screw hole side core pulling mold structure according to claim 2, characterized in that: The core pulling assembly further comprises a secondary shaft (6); the fixing frame (2) is provided with a second screw sleeve (22) which is parallel to and spaced from the first screw sleeve (21); the secondary shaft (6) comprises a threaded end threadedly connected to the second screw sleeve (22) and a transfer end rotatably connected to the core pulling block (7); a second main drive gear (61) is provided on one side of the threaded end of the secondary shaft (6); the tooth thickness of the second main drive gear (61) is smaller than that of the main gear (41); the second main drive gear (61) is meshed with the main gear (41) and can slide axially relative to the main gear (41); the first main drive gear (51) and the second main drive gear (61) are respectively located on both sides of the main gear (41); and the transfer end of the first shaft (5) and the transfer end of the second shaft (6) are equidistant from the center of the core pulling block (7).

4. The screw hole side core pulling mold structure according to claim 1, characterized in that: A mounting hole is provided on a side of the core pulling block (7) facing the core pulling surface (12); the adapter end of the forming shaft (8) is rotatably inserted into the mounting hole; the forming shaft (8) is sleeved with a sealing ring (83) flush with the opening of the mounting hole; the sealing ring (83) is used to close a gap between the forming shaft (8) and the mounting hole.

5. The screw hole side core pulling mold structure according to claim 4, characterized in that: The outer diameter of the sealing ring (83) is equal to the hole diameter of the mounting hole, and the outer peripheral wall of the sealing ring (83) is in sliding contact with the hole wall of the mounting hole.

6. The screw hole side core pulling mold structure according to claim 4, characterized in that: The sealing ring (83) is made of beryllium copper.

7. The screw hole side core pulling mold structure according to claim 1, characterized in that: A cooling pipeline is provided in the interior of the molding shaft (8) along the axial direction.

8. The screw hole side core pulling mold structure according to any one of claims 1 to 7, characterized in that: There are two forming shafts (8).

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