A new gear mold structure

Abstract

The present application provides a new gear mold structure, comprising a fixed mold insert and a movable mold insert, further comprising a fixed mold insert block; a spout having an injection hole for injecting molten plastic material from an injection molding machine nozzle into a product forming position inside the mold; at least one first movable mold insert; at least one second movable mold insert, the first movable mold insert and the second movable mold insert cooperate to form a glue inlet point that can connect the water gap with the formed product; the fixed mold insert, the movable mold insert, the fixed mold insert block, the first movable mold insert and the second movable mold insert jointly enclose at least one forming position of the formed product; a ejector pin, one end of which is connected with the water gap, when the ejector pin ejects the water gap, the glue inlet point is stressed and cut off, so as to separate the water gap from the product. The original three-plate mold fine water gap mold is modified into a two-plate mold large water gap mold structure, a new spout and glue feeding mode are designed, the overall length of the water gap is shortened, thereby reducing the weight of the water gap, reducing the waste of raw materials and saving costs.

Description

Technical Field

[0001] This invention relates to the field of injection mold technology, and in particular to a novel gear mold structure. Background Technology

[0002] During the implementation of lean production, the waste of sprue marks in the production of gear series is quite serious. The total weight of the four-cavity product is 9.6g, while the weight of the sprue mark of the first cavity is 11.7g. The sprue mark accounts for a large proportion of the raw materials used in the production of the first cavity. In addition, the raw material for this production is POM. This type of material is used to produce precision transmission parts such as gears and bearings. POM recyclable material cannot be added. Therefore, the POM sprue mark material wasted in production cannot be recycled.

[0003] The formation of sprue is based on the mold structure. The existing gear mold structure uses a three-plate mold with a fine sprue structure. The raw material melt passes through the nozzle to the sprue plate and then to the mold cavity for forming. The journey is relatively long, so the weight of the sprue accounts for a large proportion of the production. The mold structure design places the injection point directly on the cross shaft of the gear. The cross shaft is a rotating mating surface with high dimensional requirements. The glue position at the injection point is the last part of the melt injected. During molding, the shrinkage is large, which can easily lead to quality abnormalities such as poor cross shaft dimensions. In addition, the flat surface at the top of the cross shaft may also have a high injection point break, causing defective products. It is necessary to manually remove the protruding injection point. Summary of the Invention

[0004] In order to overcome the above-mentioned shortcomings of the prior art, the purpose of this invention is to provide a novel gear mold structure to solve the problems mentioned in the background art.

[0005] The technical solution adopted by this invention to solve its technical problem is: a novel gear mold structure, including a fixed mold insert and a moving mold insert, and further comprising...

[0006] The fixed mold insert has a molding cavity at the top of the cross pivot of the molded product, which makes the cross pivot area of ​​the fixed mold insert form a through hole feature;

[0007] A nozzle is an injection hole that allows molten plastic material to be injected from the nozzle of an injection molding machine into the mold at the product molding position.

[0008] At least one first moving mold insert;

[0009] At least one second moving mold insert, wherein the first moving mold insert and the second moving mold insert cooperate to form a sprue point that allows the sprue to be connected to the molded product;

[0010] The fixed mold insert, the moving mold insert, the fixed mold block, the first moving mold block and the second moving mold block together form at least one molding position of the molded product.

[0011] The ejector pin has one end connected to the sprue. When the ejector pin pushes out of the sprue, it forces the glue inlet point to be cut off, thereby separating the sprue from the product.

[0012] As a further improvement of the present invention: the fixed mold insert, the moving mold insert and the nozzle together form the sprue position for sprue forming, and the first moving mold insert and the second moving mold insert cooperate to form the glue injection point where the sprue is separated from the molded product.

[0013] As a further improvement of the present invention: the nozzle is connected to the fixed mold insert, the nozzle is provided with an injection end that cooperates with the injection molding machine nozzle and a hot nozzle that extends to the other end of the fixed mold insert, the injection hole connects the injection end and the hot nozzle, so that molten plastic material is injected from the injection molding machine nozzle into the mold.

[0014] As a further improvement of the present invention: any of the fixed mold inserts is connected to the fixed mold insert. When the fixed mold insert is connected to the fixed mold insert, the molding cavity at the top of the cross shaft of the fixed mold insert is connected to the molding position so that the molded product forms a cross shaft.

[0015] As a further improvement of the present invention: the moving mold insert has a placement groove for the first moving mold insert and the second moving mold insert to be formed in conjunction, and the first moving mold insert and the second moving mold insert are arranged in the placement groove to form a tunnel submersible gate injection point.

[0016] As a further improvement of the present invention, it also includes a fixed template and a fixed template base plate;

[0017] The fixed mold base plate is used for positioning and fixing the mold on the fixed worktable of the injection molding machine during mold production;

[0018] The fixed template is assembled on the fixed mold fixing plate. The fixed template has a nozzle through hole for the injection end of the nozzle to fit. The fixed template is equipped with the fixed mold insert to press the nozzle and the fixed mold insert together.

[0019] As a further improvement of the present invention, it also includes a movable template and a movable template fixing plate;

[0020] The moving mold fixing plate is used to position and fix the mold on the moving worktable of the injection molding machine during mold production;

[0021] The moving template is installed with the moving mold insert to press the first moving mold insert into place. When the moving template and the moving mold fixing plate are connected, they enclose and form an ejection cavity.

[0022] As a further improvement of the present invention: a face pin plate and a bottom pin plate are also provided in the ejection cavity between the moving template and the moving template fixing plate, and the face pin plate and the bottom pin plate are movably arranged in the ejection cavity;

[0023] The face pin plate and the bottom pin plate are fixedly connected. The face pin plate is located on the side close to the moving template and is used to position and assemble the ejector pin.

[0024] The bottom pin plate is located on the side near the moving mold fixing plate, and the bottom pin plate is used to press and position the ejector pins.

[0025] A limiting post is provided on the side of the face needle plate near the moving template. The limiting post is used to limit the movement distance of the face needle plate and the bottom needle plate.

[0026] As a further improvement of the present invention: the needle plate is also provided with a sleeve and a sleeve needle.

[0027] The ejector pin is a deep hole that extends through the face pin plate, the moving template, and the moving mold insert to the molding position of the molded product;

[0028] One end of the ejector sleeve is limited on the face needle plate, and the other end of the ejector sleeve extends along the ejector sleeve needle through the face needle plate, the moving template and the moving mold insert to the forming position;

[0029] During injection molding, the end faces of the ejector sleeve and ejector pin are flush with each other to seal the molding position of the product.

[0030] As a further improvement of the present invention: one end of the ejector pin is limited on the face pin plate, and the other end of the ejector pin extends through the face pin plate, the moving template and the moving mold insert to the sprue position of the sprue forming.

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] 1. This invention transforms the original three-plate mold with a fine sprue into a two-plate mold with a large sprue structure, designs a new nozzle and glue injection method, shortens the overall length of the sprue, thereby reducing the weight of the sprue, reducing raw material waste, and saving costs.

[0033] 2. This invention changes the gating method, replacing the original gating point which was directly applied to the top of the cross shaft with a tunnel submersible gating point. The connection between the gating point and the product is severed by the cut shape at the gating point of the first moving mold insert, achieving automatic separation of the gating point from the product. This eliminates the poor appearance quality caused by the original gating method where the gating point was forcibly pulled apart, resulting in a high break point. It also eliminates the manual step of removing the protruding gating point, saving manpower.

[0034] 3. The novel mold structure of this invention changes the original method of gluing at the cross shaft, which solves the quality problems caused by the cooling shrinkage and deformation of the cross shaft, and reduces the waste of raw materials due to product scrap. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the relationship between the product and the sprue before the rectification of the present invention.

[0036] Figure 2 This is a structural diagram illustrating the relationship between the product and the sprue in the novel mold of this invention.

[0037] Figure 3 This is a schematic diagram of the structure of the fine sprue mold before the rectification of the present invention.

[0038] Figure 4 For the present invention Figure 3 A schematic diagram of the structure in the middle section, view A.

[0039] Figure 5 This is a schematic diagram of the structure of the product and sprue produced by the fine sprue mold before the rectification of the present invention.

[0040] Figure 6 This is a schematic diagram of the structure of the novel mold of the present invention.

[0041] Figure 7 For the present invention Figure 6 A structural schematic diagram of the middle section, view B.

[0042] Figure 8 This is a schematic diagram of the structure of the product and the sprue produced by the novel mold fine sprue mold of the present invention.

[0043] Figure 9 For the present invention Figure 8 A structural diagram showing the shape of the glue inlet cut at point C in the middle section.

[0044] Figure 10 This is an exploded structural diagram of the fixed mold insert of the novel mold of the present invention.

[0045] Figure 11 This is a schematic diagram of the assembly structure of the novel mold insert of the present invention.

[0046] Figure 12 This is an exploded structural diagram of the moving mold insert of the novel mold of the present invention.

[0047] Figure 13 This is a schematic diagram of the assembly structure of the novel moving mold insert of the present invention.

[0048] Numbered in the diagram: 1. Product, 2. Sprue, 3. Fixed mold base plate, 4. Sprue plate, 5. Fixed mold plate, 6. Spring, 7. Tie rod, 8. Pull pin, 9. Sprue nozzle, 10. Resin opener / closer, 11. Sprue insert, 12. Fixed mold insert, 13. Fixed mold insert, 14. Moving mold insert, 15. First moving mold insert, 16. Second moving mold insert, 17. Moving mold plate, 18. Ejector sleeve, 19. Ejector sleeve pin, 20. Limiting pin, 21. Top pin plate, 22. Bottom pin plate, 23. Moving mold fixing plate, 24. Ejector pin, 25. Glue inlet. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0050] The present invention will now be further described with reference to the accompanying drawings and embodiments: A novel gear mold structure includes a fixed mold insert 13 and a moving mold insert 14, and a fixed mold block 12 having a molding cavity at the top of the cross shaft of the molded product 1, so that the cross shaft area of ​​the fixed mold insert 13 forms a through hole feature; a nozzle 9 having an injection hole for injecting molten plastic material into the mold from the injection molding machine nozzle to the molding position of the product 1; at least one first moving mold block 15; at least one second moving mold block 16, the first moving mold block 15 and the second moving mold block 16 cooperate to form a sprue 25 that can connect the sprue 2 to the molded product 1; the fixed mold insert 13, the moving mold insert 14, the fixed mold block 12, the first moving mold block 15 and the second moving mold block 16 together form at least one molding position of the molded product 1; an ejector pin 24, one end of which is connected to the sprue 2, when the ejector pin 24 ejects the sprue 2, the sprue point 25 is cut off by force, so as to separate the sprue 2 from the product 1. This invention changes the glue injection method, changing the original glue injection point 25 directly to the top of the cross shaft to a tunnel submersible gating point 25. The connection between the sprue 2 and the product 1 is cut off by the cut shape of the first moving mold insert 15 at the glue injection point 25, realizing automatic separation of the sprue 2 and the product 1. Furthermore, the novel mold structure of this invention changes the original glue injection method of the glue injection point 25 at the cross shaft.

[0051] In one embodiment, by setting four first moving mold inserts 15 and two second moving mold inserts 16, such that one second moving mold insert 16 corresponds to two first moving mold inserts 15, four molding positions of the molded product 1 can be formed.

[0052] Furthermore, such as Figure 10-13 As shown, the fixed mold insert 13, the moving mold insert 14, and the nozzle 9 together form the sprue 2 position for sprue 2 formation. The first moving mold insert 15 and the second moving mold insert 16 cooperate to form the injection point 25 for separating the sprue 2 from the molded product 1. The fixed mold insert 13 has an injection point 25 that allows molten injection material to enter the molding position of the molded product 1 from the sprue 2 position. At the same time, the injection point 25 formed by the first moving mold insert 15 and the second moving mold insert 16 cooperates to conduct the two injection points 25. When the mold is opened, the cut shape (point) of the injection point 25 on the first moving mold insert 15 is subjected to force and cut off, realizing the automatic separation of the sprue 2 from the product 1.

[0053] Furthermore, such as Figure 10-11 As shown, the nozzle 9 is connected to the fixed mold insert 13. The nozzle 9 has an injection end that mates with the injection molding machine nozzle and a hot nozzle extending to the other end of the fixed mold insert 13. The injection hole connects the injection end and the hot nozzle, allowing molten plastic material to be injected into the mold from the injection molding machine nozzle. The main function of the nozzle 9 is to allow molten plastic material to be injected from the injection molding machine nozzle into the runner component inside the mold, which is the main runner of the sprue 2. The nozzle 9 is connected to the fixed mold insert 13 to shorten the runner length, thereby reducing the overall weight of the sprue 2 and reducing raw material waste.

[0054] Furthermore, such as Figure 10-11 As shown, any of the fixed mold inserts 12 are connected to the fixed mold insert 13. When the fixed mold insert 12 is connected to the fixed mold insert 13, the forming cavity at the top of the cross shaft of the fixed mold insert 12 is connected to the forming position, so that the formed product 1 forms the cross shaft. The main function of the fixed mold insert 13 is to form the top of the cross shaft of the formed product 1, making it a separately detachable component. This changes the cross shaft area of ​​the fixed mold insert 13 from the original closed area to a through-hole feature, which can be directly wire-cut to form the cross shaft feature, simplifying the processing and ensuring the mold precision requirements. It also changes the original glue injection point 25 to the glue injection method of the cross shaft, solving the quality problem of poor cross shaft cooling shrinkage deformation and reducing the waste of raw materials caused by the scrapping of product 1.

[0055] Furthermore, such as Figure 12-13 As shown, the moving mold insert 14 has a placement groove for the first moving mold insert 15 and the second moving mold insert 16 to be formed together. The first moving mold insert 15 and the second moving mold insert 16 are arranged in the placement groove to form the tunnel submersible gate injection point 25. The main functions of the moving mold insert 14 are to assemble the first moving mold insert 15 and the second moving mold insert 16; and to form the sprue 2 together with the fixed mold insert 13, without forming the characteristic glue position of the product 1.

[0056] Furthermore, such as Figure 6 , Figure 8 As shown, it also includes a fixed template 5 and a fixed template base plate 3;

[0057] The fixed mold base plate 3 is used to position and fix the mold on the fixed worktable of the injection molding machine during mold production; the fixed mold base plate 3 is the outermost part of the fixed mold part, and is positioned and fixed on the fixed worktable of the injection molding machine during mold production.

[0058] The fixed template 5 is assembled on the fixed mold fixing plate. The fixed template 5 has a through hole for the injection end of the nozzle 9 to fit. The fixed template 5 is equipped with the fixed mold insert 13 to press the nozzle 9 and the fixed mold insert 12 together. The fixed template 5 is the second large component on the fixed mold part. It is assembled on the fixed mold fixing plate and serves to assemble the fixed mold insert 13 and press the nozzle 9.

[0059] Furthermore, such as Figure 6 , Figure 8 As shown, it also includes a moving template 17 and a moving template fixing plate 23;

[0060] The moving mold fixing plate 23 is used to position and fix the mold on the moving worktable of the injection molding machine during mold production; the moving mold fixing plate 23 is the outermost template of the moving mold part, and is positioned and fixed on the moving worktable of the injection molding machine during mold production.

[0061] The moving template 17 is fitted with the moving mold insert to press the first moving mold insert 15 together. When the moving template 17 and the moving mold fixing plate 23 are connected, they enclose each other to form an ejection cavity. The moving template 17 is the template closest to the inside of the mold in the moving mold part of the mold, and the moving mold insert 14 is assembled inside it.

[0062] Specifically, such as Figure 6 , Figure 8 As shown, a face pin plate 21 and a bottom pin plate 22 are also provided in the ejection cavity between the moving template 17 and the moving template fixing plate 23. The face pin plate 21 and the bottom pin plate 22 are movably arranged in the ejection cavity.

[0063] The face pin plate 21 and the bottom pin plate 22 are fixedly connected. The face pin plate 21 is located on the side close to the moving template 17. The face pin plate 21 is used to position and assemble the ejector pin 24. The face pin plate 21 is the first plate of the ejector part and is assembled on the bottom pin plate 22. Its main function is to assemble the ejector pin 24.

[0064] The bottom pin plate 22 is located on the side near the moving mold fixing plate 23. The bottom pin plate 22 is used to press and position the ejector pin 24. The bottom pin plate 22 is the second plate of the ejector part, which is assembled under the face pin plate 21. Its main purpose is to press the ejector pin 24 assembled on the face pin plate 21 to prevent the ejector pin 24 from retracting and falling off.

[0065] A limiting post 20 is provided on the side of the face needle plate 21 near the moving template 17. The limiting post 20 is used to limit the movement distance of the face needle plate 21 and the bottom needle plate 22. The limiting post 20 is mounted on the face needle plate 21 and plays a role in limiting the ejection stroke of the face needle plate 21 and the bottom needle plate 22, thereby limiting the ejection distance of the ejector pin 24.

[0066] Furthermore, such as Figure 6 , Figure 8 As shown, the needle plate 21 is also provided with a sleeve 18 and a sleeve needle 19:

[0067] The ejector pin 19 is a deep hole that extends through the face pin plate 21, the moving template 17 and the moving mold insert 14 to the molding position of the molded product 1;

[0068] One end of the ejector sleeve 18 is limited on the face needle plate 21, and the other end of the ejector sleeve 18 extends along the ejector sleeve needle 19 through the face needle plate 21, the moving template 17 and the moving mold insert 14 to the forming position;

[0069] When injection molding product 1, the end faces of the ejector sleeve 18 and the ejector pin 19 are flush with each other to seal the molding position of the molded product 1.

[0070] Furthermore, such as Figure 6 , Figure 8 As shown, one end of the ejector pin 24 is limited on the face pin plate 21, and the other end of the ejector pin 24 extends through the face pin plate 21, the moving template 17, and the moving mold insert 14 to the position of the sprue 2. The ejector pin 24 ejects the sprue 2, causing the cut shape (point) at the glue injection point 25 on the first moving mold insert 15 to be cut off by force, thereby realizing the automatic separation of the sprue 2 from the product 1.

[0071] In existing technologies, such as Figure 3 , Figure 5 As shown, the injection molding and mold opening steps of the three-plate mold before rectification and the injection molding and mold opening steps of the new mold are introduced as follows:

[0072] I. As shown in the figure, Figure 3 As shown, the injection molding steps of the three-plate mold for the sprue 2 before rectification are as follows:

[0073] 1. The injection molding machine barrel is heated and melted, and then pressurized to inject the molten material into the nozzle 9 through the injection molding machine nozzle;

[0074] 2. The fusion body is then injected into the template 5 through nozzle 9;

[0075] 3. Then, the injection is performed from the template 5 onto the sprue insert 11;

[0076] 4. The molten material then passes through the sprue insert 11 to the original mold insert 12;

[0077] 5. Then it flows through the original mold insert 12 to the fixed mold insert 13;

[0078] 6. Finally, the first moving mold insert 15, the second moving mold insert 16, the ejector sleeve 18, and the ejector pin 19 are reached;

[0079] The molten material forms the adhesive feature of product 1 through 9 components;

[0080] II. Figure 5 The following are the mold opening steps for the three-plate mold before rectification:

[0081] Before the rectification, the fixed mold part consisted of a fixed mold base plate 3, a sprue plate 4, a fixed mold plate 5, a spring 6, a tie rod 7, a pull pin 8, a nozzle 9, a resin opener / closer 10, a sprue insert 11, the original fixed mold insert 12, and a fixed mold insert 13; the moving mold part before the rectification consisted of a moving mold insert 14, a first moving mold insert 15, a second moving mold insert 16, a moving mold plate 17, an ejector sleeve 18, an ejector sleeve pin 19, a limit post 20, a face pin plate 21, a bottom pin plate 22, and a moving mold fixing plate 23.

[0082] 1. During the first step of mold opening, the sprue plate 4 and the fixed mold plate 5 separate under the elastic force of spring 6. At this time, the sprue 2 is forcibly pulled apart from the product 1.

[0083] 2. In the second step, when the friction of the resin opener 10 between the fixed mold plate 5 and the moving mold plate 17 acts as a pulling force, the fixed mold base plate 3 and the sprue plate 4 separate first, and the ejected sprue 2 is taken away by the robot and thrown into the sprue 2 car.

[0084] 3. The third step is to continue mold opening. The fixed mold plate 5 and the moving mold plate 17 are separated. The ejector sleeve 18 ejects product 1 and it falls into the plastic frame containing product 1. At this point, the mold opening is completed.

[0085] The molding principle of Product 1 is that the plastic raw material is heated and melted in the injection molding machine barrel, and then the molten material is injected into the mold cavity from the injection point 25 under pressure. The feature of Product 1 at the injection point 25 is the last injection molding, so the temperature at this point is relatively high. When the mold opens, the molded Product 1 will cool and shrink when it encounters air. The feature of Product 1 at the injection point 25 (cross pivot) shrinks a lot, which can easily cause quality problems such as cross pivot deformation or dimensional defects. The new mold structure invented this time changes the original injection method of the injection point 25 at the cross pivot, thereby solving the hidden quality problems such as cross pivot deformation and reducing the waste of raw materials caused by the scrapping of Product 1.

[0086] In this embodiment, as Figure 6 The injection molding steps of the new mold after rectification are as follows:

[0087] 1. The injection molding machine barrel is heated and melted, and then pressurized to inject the molten material into the nozzle 9 through the injection molding machine nozzle;

[0088] 2. The molten material is then injected into the moving mold insert 14 through nozzle 9;

[0089] 3. The fusion process then proceeds to the first moving mold insert 15;

[0090] 4. The fused body then passes through the first moving mold insert 15 to the second moving mold insert 16;

[0091] 5. Finally, the ejector sleeve 18, ejector pin 19, mold insert 12, and mold insert 13 are reached;

[0092] The material melt forms the adhesive feature of product 1 through 8 components.

[0093] like Figure 8 The following are the steps for opening the new mold after rectification:

[0094] After rectification, the fixed mold part is composed of a fixed mold base plate 3, a fixed mold plate 5, a squeegee 9, a fixed mold insert 12, and a fixed mold insert 13 as a whole; after rectification, the moving mold part is composed of a first moving mold insert 15, a second moving mold insert 16, a moving mold plate 17, an ejector sleeve 18, an ejector sleeve pin 19, a limit post 20, a face pin plate 21, a bottom pin plate 22, a moving mold fixing plate 23, and an ejector pin 24.

[0095] 1. For example Figure 8 As shown, during the first step of mold opening, the fixed mold part assembled on the front plate of the injection molding machine and the moving mold part assembled on the rear plate of the injection molding machine are separated. The moving mold part is assembled on the rear plate of the injection molding machine, and the rear plate can move. Therefore, mold opening is achieved by the moving mold part moving backward, that is, the rear plate of the injection molding machine moves backward, taking the moving mold part away from the fixed mold part to achieve mold opening. At this time, the modified nozzle 9, fixed mold insert 12, and fixed mold insert 13 are assembled in the fixed platen 5 and are also fixed.

[0096] 2. For example Figure 8 As shown, in the second step, the ejector roller of the injection molding machine pushes the face pin plate 21 and the bottom pin plate 22 forward from the moving mold KO hole. The ejector pin 24 and the ejector sleeve 18 mounted on the bottom plate of the ejector pin 24 also move forward synchronously. The ejector pin 24 ejects the sprue 2, while the ejector sleeve 18 ejects the product 1. At this time, the moving mold insert 14 and the first moving mold insert 15 are fixed, while the sprue 2 and the product 1 are ejected and moved at the same time. Therefore, the cut shape (point) at the injection point 25 on the moving mold insert will cut off the connection between the sprue 2 and the product 1, realizing the automatic separation of the sprue 2 and the product 1. The sprue 2 is taken away by the robot and thrown into the sprue 2 cart, while the product 1 falls into the plastic frame containing the product 1. Thus, the mold opening is completed.

[0097] Comparing the mold-making steps, it can be seen that the new mold structure based on stable quality and cost reduction for gear production has fewer steps and a simpler structure than the previous three-plate mold with fine sprue 2. It can save the entire production cycle during injection molding, thereby improving production efficiency.

[0098] This invention, through technical means, designs a novel mold structure for gear production based on stable quality and cost reduction. Utilizing the principle that the shortest distance between two points is a straight line and that steel has a higher density than POM (polypropylene oxide), it transforms the original three-plate mold with a small sprue 2 into a two-plate mold with a large sprue 2. A new nozzle 9 and injection method are designed, shortening the overall length of the sprue 2, thereby reducing its weight, minimizing raw material waste, and saving costs. This invention changes the injection method, replacing the original injection point 25 directly at the top of the cross shaft with a tunnel submersible injection point 25. Utilizing the principle that steel has a higher density than POM, the cut shape (pointed edge) at the injection point 25 of the first moving mold insert 15 severs the connection between the sprue 2 and the product 1, achieving automatic separation of the sprue 2 and the product 1. This eliminates the poor appearance quality caused by the original method of forcibly pulling the sprue 2 apart from the product 1, resulting in a high break point at the injection point 25. It also eliminates the manual step of removing the protruding injection point 25, saving labor. The novel mold structure of this invention changes the original glue injection point 25 to the cross shaft injection method, which solves the quality problem of poor quality caused by cooling shrinkage deformation of the cross shaft and reduces the waste of raw materials caused by product 1 being scrapped.

[0099] In summary, after reading this invention document, those skilled in the art can make various other corresponding modifications to the technical solutions and concepts based on this invention without creative mental effort, and all of these modifications fall within the scope of protection of this invention.

Claims

1. A novel gear mold structure comprising a fixed mold insert and a movable mold insert, characterized in that, Also included are a fixed mold insert; a nozzle having an injection hole for injecting molten plastic material from an injection molding machine nozzle into a product forming position inside the mold; at least one first movable mold insert; at least one second movable mold insert, the first and second movable mold inserts cooperating to form a gate point for connecting a sprue to a formed product; the fixed mold insert, the movable mold insert, the fixed mold block, the first movable mold insert, and the second movable mold insert collectively defining at least one product forming position; a ejector pin having one end connected to the sprue, the ejector pin cutting the gate point when the ejector pin ejects the sprue to separate the sprue from the product; the fixed mold insert, the movable mold insert, and the nozzle collectively defining a sprue forming position for forming the sprue, the first and second movable mold inserts cooperating to form a gate point for separating the sprue from the formed product; any of the fixed mold blocks being connected to the fixed mold insert, the fixed mold block, when connected to the fixed mold insert, having a cross shaft top end forming cavity in communication with the product forming position to form a cross shaft in the formed product; 2. A novel gear mold structure according to claim 1, characterized in that, the nozzle being connected to the fixed mold insert, the nozzle having an injection end for cooperating with the injection molding machine nozzle and a hot nozzle extending from the other end of the fixed mold insert, the injection hole being in communication with the injection end and the hot nozzle to allow molten plastic material to be injected from the injection molding machine nozzle into the interior of the mold; 3. A novel gear mold structure according to claim 1, characterized in that, the movable mold insert having a placement slot for cooperating with the first and second movable mold inserts, the first and second movable mold inserts being disposed in the placement slot to cooperate to form a tunnel submarine gate point; 4. A novel gear mold structure according to claim 1, characterized in that, a fixed mold plate and a fixed mold base plate are also included; the fixed mold base plate being used to be positioned and fixed on a fixed workbench surface of the injection molding machine during mold production; the fixed mold plate being assembled on the fixed mold base plate, the fixed mold plate having a nozzle through hole for cooperating with the injection end of the nozzle, the fixed mold plate mounting the fixed mold insert to press the nozzle and the fixed mold block; 5. A novel gear mold structure according to claim 4, wherein a movable mold plate and a movable mold base plate are also included; the movable mold base plate being used to be positioned and fixed on a movable workbench surface of the injection molding machine during mold production; the movable mold plate mounting the movable mold insert to press the first movable mold insert, the movable mold plate and the movable mold base plate, when connected, collectively defining an ejection cavity; 6. A novel gear mold structure according to claim 5, wherein a face pin plate and a bottom pin plate being further disposed in the ejection cavity between the movable mold plate and the movable mold base plate, the face pin plate and the bottom pin plate being movably disposed in the ejection cavity; the face pin plate and the bottom pin plate being fixedly connected, the face pin plate being disposed on the side close to the movable mold plate, the face pin plate being used to position and assemble the ejector pin; the bottom pin plate being disposed on the side close to the movable mold base plate, the bottom pin plate being used to press and position the ejector pin; a limiting post being disposed on the side of the face pin plate close to the movable mold plate, the limiting post being used to limit the movement distance of the face pin plate and the bottom pin plate.

7. A novel gear mold structure according to claim 6, wherein the face pin plate further having a barrel and a barrel pin: the barrel pin being a deep hole extending through the face pin plate, the movable mold plate, and the movable mold insert to the product forming position; one end of the barrel being limited on the face pin plate, the other end of the barrel extending along the barrel pin through the face pin plate, the movable mold plate, and the movable mold insert to the product forming position; during injection molding of the product, the end faces of the barrel and the barrel pin flushly seal the product forming position.

8. A novel gear mold structure according to claim 1, characterized by, One end of the ejector pin is limited on the face plate, and the other end of the ejector pin extends to the nozzle position of the nozzle forming through the face plate, the movable die plate and the movable die insert.

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