Injection mold with automatic sprue removing structure

Abstract

The invention discloses an injection mold with an automatic pouring gate removing structure in the field of injection molds, which comprises a fixed mold assembly, a movable mold assembly and the automatic pouring gate removing structure, the automatic pouring gate removing structure is arranged on the movable mold assembly and is used for automatically separating a product from pouring gate waste after injection molding is completed, and the automatic pouring gate removing structure is arranged on the movable mold assembly. The automatic pouring gate removing structure comprises a tooth core, a transmission assembly and an ejection assembly, a pouring gate groove is formed in the top end of the tooth core and used for containing a pouring gate formed by injection molding materials, the transmission assembly is connected with the tooth core so as to drive the tooth core to rotate, the tooth core drives the pouring gate to rotate together, and therefore the pouring gate is separated from a product. In the rotating process, the threaded cavity groove formed in the side face of the tooth core moves relative to the threaded structure on the inner wall of the product, the tooth core and the product are loosened, the ejection assembly is used for ejecting the sprue out of the tooth core after the tooth core rotates, and rapid separation of the sprue and the tooth core is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of injection molds, in particular to an injection mold with an automatic degating gate structure. Background Art

[0002] With the widespread application of injection molding technology in industrial production, the requirements for product quality and production efficiency are constantly improving. As a common gate form, side gate has the advantages of simple structure, easy processing, and wide application range, and has been widely used in injection molds.

[0003] After molding, products with threaded structures have a strong bonding force between the product and the core due to the interlocking effect of the threads. Traditional ejection methods make it difficult to smoothly remove the product from the core. If forced ejection is used, the threads of the product may be stretched or torn, or the core surface may be worn, affecting the service life of the mold and the quality of the product.

[0004] Moreover, during the demolding process, due to the large friction and bonding force between the product and the core, the traditional demolding method may cause the product to be subjected to uneven force, thereby causing the product to deform. Especially for some plastic products with thin walls, complex shapes and threads, the traditional demolding method may cause the shape of the product to be distorted and fail to meet the design requirements. Summary of the Invention

[0005] In order to overcome the shortcomings of the existing technical solutions, the present invention provides an injection mold with an automatic de-gating gate structure, which can effectively solve the technical problem that after the product with a threaded structure is formed, due to the bite effect of the thread, the bonding force between the product and the core is large, and the traditional ejection demoulding method is difficult to make the product smoothly separated from the core. If forced ejection is performed, the thread of the product may be pulled or torn, or the surface of the core may be worn, affecting the service life of the mold and the quality of the product.

[0006] The technical solution adopted by the present invention to solve its technical problems is: an injection mold with an automatic degating structure, including a fixed mold assembly, a movable mold assembly and an automatic degating structure, the automatic degating structure is arranged on the movable mold assembly, and is used to automatically separate the product from the gate waste after the injection molding is completed, the automatic degating structure includes a core, a transmission assembly and an ejection assembly, a gate groove is provided at the top of the core, the gate groove is used to accommodate the gate formed by the injection molding material, the transmission assembly is connected to the core to drive the core to rotate and separate the product from the gate, and the ejection assembly is used to eject the gate from the core after the core rotates.

[0007] Furthermore, the fixed mold assembly includes a fixed mold base plate, a cavity plate, a hot runner plate, a main channel arranged in the hot runner plate, and a branch channel connected to the main channel. The cavity plate is equipped with a first front mold insert and a second front mold insert. The first front mold insert is mounted on the outside of the second front mold insert, and the first front mold insert and the second front mold insert constitute a cavity for molding the shape of the plastic product. The fixed mold base plate is equipped with nozzles corresponding to the number of branch channels. The nozzles are provided with melt channels, and the ends of the branch channels are connected to the melt channels.

[0008] Furthermore, the movable mold assembly includes a movable mold base plate and a movable mold support plate, and also includes a first limiting component and a second limiting component. The first limiting component includes a first limiting screw and a first spring sleeved on the outside thereof, and the second limiting component includes a second limiting screw and a second spring sleeved on the outside thereof. The first spring and the second spring are used to bounce open the movable mold support plate and the movable mold base plate.

[0009] Furthermore, the transmission assembly includes a driving member, a driving gear and a transmission gear. The tooth core is formed with an engaging portion. The driving member drives the driving gear to rotate. The driving gear and the transmission gear engage with each other. The transmission gear further engages with the engaging portion of the tooth core, causing the tooth core to rotate.

[0010] Furthermore, the driving member includes a screw and an inner multi-wire sleeve, one end of the screw is connected to the fixed mold assembly, the outer wall of the screw is provided with teeth, the inner wall of the inner multi-wire sleeve is engaged with the teeth, and the inner multi-wire sleeve is engaged with the driving gear.

[0011] Furthermore, the ejector assembly includes an ejector plate and an ejector pin. The ejector pin is assembled on the ejector plate and moves up and down together with the ejector pin. When the ejector pin rises, the gate is ejected from the gate groove of the core.

[0012] Furthermore, a sliding groove is opened in the center of the tooth core, the sliding groove is communicated with the gate groove, the ejector is arranged inside the sliding groove, the ejector is coaxial with the sliding groove, and slides along the sliding groove.

[0013] Furthermore, a threaded cavity groove for forming the internal thread structure of the product is provided on the side of the core, a raised portion is formed on the top of the core, a gate groove is provided at the center of the raised portion, and a glue injection channel is provided on the side of the raised portion, and the glue injection channel is connected to the gate groove to form a lateral glue feeding path.

[0014] Furthermore, the outer side of the tooth core is coaxially equipped with a anti-rotation tooth insert, which is used to form a anti-rotation structure on the inner wall of the molded product. The outer side of the anti-rotation tooth insert is fitted with a push tube, which is used to push the product out of the tooth core during demolding.

[0015] Furthermore, the top end surface of the anti-rotation tooth insert is provided with a plurality of spaced-apart protrusions, and a groove is formed between two adjacent protrusions.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The injection mold is equipped with an automatic degating structure, which is set on the movable mold assembly and is used to automatically separate the product from the gate waste after injection molding is completed. The automatic degating structure includes a thread core, a transmission assembly and an ejection assembly. The transmission assembly is connected to the thread core, driving the thread core to rotate. The thread core drives the gate to rotate together, thereby realizing the separation of the gate and the product. Since the process of separating the gate and the product is completed by the rotation of the thread core, the force generated by the rotational motion is evenly distributed and continuous, and does not generate sudden and excessive impact forces like traditional degating methods. This uniform force transmission method can effectively avoid excessive impact on the thread structure of the product, thereby protecting the integrity and matching accuracy of the thread structure, and ensuring that the product can still meet the design thread performance requirements after degating;

[0018] During the rotation process, the threaded cavity groove set on the side of the core moves relative to the thread structure on the inner wall of the product. This relative movement gradually reduces the thread bite between the core and the product until the core and the product are loosened. This step creates favorable conditions for the subsequent demoulding operation.

[0019] Subsequently, the push tube pushes the product out from the core. Since the product and the core are loosened by the rotation of the core before demolding, the bonding force between the product and the core is greatly reduced. Therefore, the push tube is subjected to relatively uniform resistance when ejecting the product, avoiding the problem of product deformation caused by excessive local force in traditional demolding methods. At the same time, when the ejector pin rises, it pushes the gate out of the gate groove of the core, realizing the rapid separation of the gate and the core. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The figure is a schematic diagram of the overall structure of an injection mold with an automatic degating structure;

[0021] Figure 2 A cross-sectional view of an injection mold with an automatic degating structure;

[0022] Figure 3 for Figure 2 A magnified view of the structure of part A;

[0023] Figure 4 This is the separation structure diagram of the gate and the core;

[0024] Figure 5 This is a cross-sectional view of the tooth core;

[0025] Figure 6 is a structural diagram of the transmission component;

[0026] Figure 7This is a three-dimensional image of a tooth core.

[0027] Numbers in the figure:

[0028] 1. Hot runner plate; 2. Fixed mold base plate; 3. Cavity plate; 4. Moving mold support plate; 5. Moving mold base plate; 6. Ejector plate; 7. Screw; 8. Inner double-wire sleeve; 9. First spring; 10. Second limit screw; 11. Second spring; 12. Ejector; 13. Product; 14. Gate; 15. Main channel; 16. Branch channel; 17. Nozzle; 18. First limit screw; 19. First front mold insert; 20. Second front mold insert; 21. Core; 22. Gate groove; 23. Engaging part; 24. Sliding groove; 25. Push tube; 26. Stop tooth insert; 28. Transmission gear; 29. Driving gear; 30. Groove; 31. Threaded cavity groove; 32. Raised part; 33. Injection channel; 34. Bump; 35. Push rod. DETAILED DESCRIPTION

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0030] like Figure 1-7 As shown, the present invention provides an injection mold with an automatic degating gate 14 structure, including a fixed mold assembly, a movable mold assembly and an automatic degating gate 14 structure, the automatic degating gate 14 structure is arranged on the movable mold assembly, and is used to automatically separate the product 13 from the gate 14 waste after the injection molding is completed, the automatic degating gate 14 structure includes a core 21, a transmission assembly and an ejection assembly, a gate groove 22 is provided at the top of the core 21, the gate groove 22 is used to accommodate the gate 14 formed by the injection molding material, the transmission assembly is connected to the core 21 to drive the core 21 to rotate and separate the product 13 from the gate 14, and the ejection assembly is used to eject the gate 14 from the core 21 after the core 21 rotates.

[0031] The fixed mold assembly includes a fixed mold base plate 2, a cavity plate 3, a hot runner plate 1, a main channel 15 arranged in the hot runner plate 1 and a branch channel 16 connected to the main channel 15, the cavity plate 3 is equipped with a first front mold insert 19 and a second front mold insert 20, the first front mold insert 19 is sleeved on the outside of the second front mold insert 20, and the first front mold insert 19 and the second front mold insert 20 constitute a cavity for molding the shape of the plastic product 13, the fixed mold base plate 2 is equipped with nozzles 17 corresponding to the number of branch channels 16, and the nozzles 17 are provided with melt flow The end of the branch channel 16 is interconnected with the melt flow channel, so that a nozzle 17 is provided for each product 13. On the one hand, the mold parting surface is reduced, and the melt directly enters the melt flow channel of the nozzle 17 through the branch channel 16, reducing the problem of uneven melt distribution in the branch channel 16 network. On the other hand, it can effectively reduce the flow path length of the melt from the main channel 15 to the product 13, reducing the heat loss and pressure drop of the melt during the flow process. The shortened melt flow path and the uniform filling reduce the residual stress inside the product 13.

[0032] The movable mold assembly includes a movable mold base plate 5 and a movable mold support plate 4, and the transmission assembly includes a driving member, a driving gear 29 and a transmission gear 28. The driving member includes a screw 7 and an inner multi-wire sleeve 8. One end of the screw 7 is connected to the fixed mold assembly. The outer wall of the screw 7 is provided with teeth, and the inner wall of the inner multi-wire sleeve 8 is engaged with the teeth. Therefore, when the movable mold assembly moves away from the fixed mold assembly, the screw 7 rotates the inner multi-wire sleeve 8, and the inner multi-wire sleeve 8 engages with the driving gear 29. The driving gear 29 further engages with the transmission gear 28. The tooth core 21 is formed with an engaging portion 23. The transmission gear 28 engages with the engaging portion 23 of the tooth core 21, so that the tooth core 21 rotates. The tooth core 21 drives the gate 14 to rotate together, thereby realizing the separation of the product 13 and the gate 14;

[0033] The center of the tooth core 21 is provided with a sliding groove 24, which is connected to the gate groove 22. The ejector pin 12 is arranged inside the sliding groove 24. The ejector pin 12 is coaxial with the sliding groove 24 and slides along the sliding groove 24. The side of the tooth core 21 is provided with a threaded cavity groove 31 for forming the internal thread structure of the product 13. The top of the tooth core 21 is formed with a raised portion 32. The gate groove 22 is located at the center of the raised portion 32. A glue injection channel 33 is provided on the side of the raised portion 32. The glue injection channel 33 is connected to the gate groove 22. A lateral glue feeding path is formed, and a stop tooth insert 26 is coaxially assembled on the outer side of the tooth core 21. The stop tooth insert 26 is used to prevent the inner wall of the molded product 13 from rotating. Specifically, the top surface of the stop tooth insert 26 is provided with a plurality of spaced protrusions 34, and a groove 30 is formed between two adjacent protrusions 34. During molding, the inner wall of the product 13 is formed with a stop block. When the tooth core 21 drives the gate 14 to rotate, the product 13 is stationary relative to the tooth core 21 under the cooperation of the stop block and the protrusion 34;

[0034] The first limiting component includes a first limiting screw 18 and a first spring 9 sleeved on the outside thereof, and the second limiting component includes a second limiting screw 10 and a second spring 11 sleeved on the outside thereof. The first spring 9 and the second spring 11 are used to spring open the movable mold support plate 4 and the movable mold base plate 5. When the fixed mold assembly and the movable mold assembly are closed, the first spring 9 and the second spring 11 are compressed. After the mold is opened, the first spring 9 and the second spring 11 spring the movable mold support plate 4 and the movable mold base plate 5 apart, and the product 13 moves together with the movable mold support plate 4 and the movable mold base plate 5. 13 produces a displacement relative to the tooth core 21, and the push tube 25 is installed on the outer side of the anti-rotation tooth insert 26. The push tube 25 is used to eject the product 13 from the tooth core 21 during demolding. The ejection assembly includes an ejector plate 6, an ejector 12 and a push rod 35. The ejector 12 and the push rod 35 are assembled on the ejector plate 6 and move up and down together. The mold pushes the ejector plate 6 to move upward. When the ejector 12 rises, the gate 14 is ejected from the gate groove 22 of the tooth core 21. When the push rod 35 rises, it drives the movable mold support plate 4 and the push tube 25 to move forward. At this time, the push tube 25 pushes the product 13 out of the anti-rotation tooth insert 26.

[0035] Working principle: The movable mold assembly is pushed by the injection molding machine's mold clamping system to move toward the fixed mold assembly. The fitting surfaces of the movable mold assembly and the fixed mold assembly are matched with high precision to form a closed cavity. The plastic particles are pushed by the injection molding machine's feeder and enter the hot runner after being heated and melted. The main channel 15 in the hot runner distributes the plastic melt to each branch channel 16 and reaches the gate 14 of the mold cavity. During the injection process, the plastic melt flows into the gate groove 22 and then flows into the mold cavity along the lateral glue feeding path until the plastic melt fills the entire mold cavity. During the filling process, the plastic melt is tightly fitted to the molding parts such as the threaded cavity groove 31 of the core 21 and the anti-rotation tooth insert 26 under the action of high pressure to form the shape of the product 13 and the product. 13 is connected to the gate 14. When the mold is opened, the injection molding machine drives the movable mold assembly to move and separate from the fixed mold assembly. The screw 7 rotates the inner multi-wire sleeve 8, and the inner multi-wire sleeve 8 drives the driving gear 29 to rotate. The driving gear 29 and the transmission gear 28 are meshed with each other. The transmission gear 28 is further meshed with the meshing portion 23 of the tooth core 21, thereby driving the tooth core 21 to rotate. During the rotation process, the tooth core 21 drives the gate 14 to rotate, so that the gate 14 is separated from the product 13. In addition, the threaded cavity groove 31 provided on the side of the tooth core 21 moves relative to the thread structure on the inner wall of the product 13 during the rotation process, so that the tooth core 21 and the product 13 are loosened. Under the cooperation of the anti-rotation block and the protrusion 34, the product 13 is stationary relative to the tooth core 21.

[0036] In addition, when the mold is opened, the first spring 9 and the second spring 11 bounce the movable mold support plate 4 and the movable mold base plate 5 apart, and the product 13 moves along with the movable mold support plate 4 and the movable mold base plate 5. The product 13 is displaced relative to the core 21, and the mold pushes the ejector plate 6 to move upward. When the ejector 12 rises, the gate 14 is ejected from the gate groove 22 of the core 21. When the push rod 35 rises, it drives the movable mold support plate 4 and the push tube 25 forward. At this time, the push tube 25 pushes the product 13 out of the anti-rotation tooth insert 26.

[0037] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

Claims

1. An injection mold with an automatic degating structure, characterized in that: It includes a fixed mold assembly, a movable mold assembly and an automatic degating gate structure. The automatic degating gate structure is arranged on the movable mold assembly and is used to automatically separate the product from the gate waste after the injection molding is completed. The automatic degating gate structure includes a core, a transmission assembly and an ejection assembly. A gate groove is arranged on the top of the core, and the gate groove is used to accommodate the gate formed by the injection molding material. The transmission assembly is connected to the core to drive the core to rotate and separate the product from the gate. The ejection assembly is used to eject the gate from the core after the core rotates.

2. The injection mold with an automatic degating structure according to claim 1, characterized in that: The fixed mold assembly includes a fixed mold base plate, a cavity plate, a hot runner plate, a main channel arranged in the hot runner plate, and a branch channel connected to the main channel. The cavity plate is equipped with a first front mold insert and a second front mold insert. The first front mold insert is mounted on the outside of the second front mold insert, and the first front mold insert and the second front mold insert constitute a cavity for molding the shape of the plastic product. The fixed mold base plate is equipped with nozzles corresponding to the number of branch channels. The nozzles are provided with melt channels, and the ends of the branch channels are connected to the melt channels.

3. The injection mold with an automatic degating structure according to claim 1, characterized in that: The movable mold assembly includes a movable mold base plate and a movable mold support plate, and also includes a first limiting component and a second limiting component. The first limiting component includes a first limiting screw and a first spring sleeved on the outside thereof, and the second limiting component includes a second limiting screw and a second spring sleeved on the outside thereof. The first spring and the second spring are used to bounce the movable mold support plate and the movable mold base plate open.

4. The injection mold with an automatic degating structure according to claim 1, characterized in that: The transmission assembly includes a driving member, a driving gear and a transmission gear. The tooth core is formed with an engaging portion. The driving member drives the driving gear to rotate. The driving gear and the transmission gear are engaged with each other. The transmission gear is further engaged with the engaging portion of the tooth core, causing the tooth core to rotate.

5. The injection mold with an automatic degating structure according to claim 4, characterized in that: The driving part includes a screw and an inner multi-wire sleeve. One end of the screw is connected to the fixed mold assembly. The outer wall of the screw is provided with teeth. The inner wall of the inner multi-wire sleeve is meshed with the teeth. The inner multi-wire sleeve is meshed with the driving gear.

6. The injection mold with an automatic degating structure according to claim 1, characterized in that: The ejector assembly includes an ejector plate and an ejector pin. The ejector pin is assembled on the ejector plate and moves up and down together with the ejector pin. When the ejector pin rises, the gate is ejected from the gate groove of the core.

7. The injection mold with an automatic degating structure according to claim 6, characterized in that: A sliding groove is provided at the center of the tooth core, the sliding groove is communicated with the gate groove, and the ejector pin is arranged inside the sliding groove. The ejector pin is coaxial with the sliding groove and slides along the sliding groove.

8. The injection mold with an automatic degating structure according to claim 7, characterized in that: A thread cavity groove for forming the internal thread structure of the product is provided on the side of the core, a raised portion is formed on the top of the core, a gate groove is provided at the center of the raised portion, and a glue injection channel is provided on the side of the raised portion. The glue injection channel is connected to the gate groove to form a lateral glue feeding path.

9. The injection mold with an automatic degating structure according to claim 1, characterized in that: The outer side of the tooth core is coaxially equipped with a rotation-stopping tooth insert, which is used to form a rotation-stopping structure on the inner wall of the molded product. The outer side of the rotation-stopping tooth insert is covered with a push tube, which is used to push the product out of the tooth core during demoulding.

10. The injection mold with an automatic degating structure according to claim 9, characterized in that: The top end surface of the anti-rotation tooth insert is provided with a plurality of protrusions distributed at intervals, and a groove is formed between two adjacent protrusions.

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