Injection mold capable of preventing strain during material returning

Abstract

The utility model provides an injection mold capable of preventing pulling during material returning, which is applied to the field of injection molds and is characterized in that a fixed mold part comprises a fixed mold base, a fixed mold plate and a fixed mold core, the fixed mold plate is mounted on the fixed mold base, and a first positioning groove for mounting the fixed mold core is formed in the surface of one side of the fixed mold plate; the fixed mold core is positioned and fixed on the fixed mold plate through the first positioning groove; the fixed mold part comprises a fixed mold base and a fixed mold plate, a through sprue bush is arranged in the fixed mold base and the fixed mold plate, a plurality of groups of water gaps are formed in the fixed mold core and are uniformly distributed in the water gaps at equal angles, the input ends of the water gaps are communicated with the output ends of the sprue bush, and the output ends of the water gaps extend to the bottom of the fixed mold core and are arranged at the top of a port of a product; by adopting the design that the water gaps which are uniformly distributed at equal angles are formed in the fixed mold core, a plastic melt can be uniformly distributed to all parts of the mold cavity after being output from the sprue bush, so that the overall appearance quality of a product is guaranteed, and the qualification rate of the product is improved.

Description

Technical Field

[0001] This application relates to the field of injection molds, and in particular to an injection mold for preventing material ejection and tearing. Background Technology

[0002] In injection molding, barrel-shaped products often have a certain depth, circumferential walls, and possible internal structures (such as slopes, undercuts, etc.) due to their shape characteristics, which makes them face many challenges in the demolding (material removal) stage.

[0003] Traditional injection molds often suffer from problems when handling material ejection for these types of products due to inadequate structural design. These problems include high friction between the product and mold cavity components, inconsistent demolding sequences, and uneven ejection force distribution. This can easily lead to surface scratches, marks, and even localized deformation, severely impacting the product's appearance and performance. Furthermore, improper ejection methods increase wear on mold components, reduce mold lifespan, and increase production costs. To overcome these shortcomings of existing technologies, it is necessary to develop an injection mold specifically designed for barrel-shaped products that effectively prevents material ejection scratches. Utility Model Content

[0004] The purpose of this application is to solve the technical problems of large surface damage and low ejection quality in existing barrel-shaped injection molded products. Compared with the prior art, it provides an injection mold that prevents tearing during ejection, used for injection molding barrel-shaped products, including a fixed mold part and a moving mold part, as detailed below:

[0005] Fixed mold part: includes fixed mold base, fixed template and fixed mold core. The fixed template is installed on the fixed mold base. One side surface of the fixed template is provided with a first positioning groove for installing the fixed mold core. The fixed mold core is positioned and fixed on the fixed template through the first positioning groove. The inner contour shape of the fixed mold core is adapted to the outer shape of the product to form the outer surface shape of the barrel-shaped product.

[0006] The fixed mold base and fixed mold plate are provided with a through sprue sleeve. The fixed mold core is provided with multiple sets of sprues. Several of the sprues are evenly distributed at equal angles inside the sprues. The input end of the sprue is connected to the output end of the sprue sleeve. The output end of the sprue extends to the bottom of the fixed mold core and is located at the top of the port of the product.

[0007] The moving mold part includes a moving mold base, a moving mold plate, and a moving mold core. The moving mold plate is mounted on the moving mold base, and a material ejector plate is slidably connected between the moving mold base and the moving mold plate.

[0008] The moving mold plate is provided with a second positioning groove for installing the moving mold core. The moving mold core is fixed in the second positioning groove. Four sets of inner sliding blocks are also slidably connected to the circumference of the moving mold core. The sliding direction of the four sets of inner sliding blocks is inclined to the axial direction of the product. The outer contour formed by the moving mold core and the four sets of inner sliding blocks after they are engaged matches the internal shape of the product. The moving mold plate is also slidably connected to four sets of outer sliding blocks in a direction parallel to its end face. The four sets of outer sliding blocks slide relative to each other in pairs. The inner contour formed by the four sets of outer sliding blocks after they are engaged matches the external shape of the product. After the fixed mold core, moving mold core, inner sliding blocks and outer sliding blocks are fully engaged, a complete cavity corresponding to the product is formed.

[0009] The bottom of each inner part block is fixed with a slanted rod, the moving mold core is provided with a slanted groove that matches the slanted rod, the bottom end of the slanted rod is fixed with a side slide block, the ejector plate is fixed with a side slide seat that matches the side slide block, the ejector plate is also fixed with a number of ejector pins, and the moving mold core is provided with an ejector pin sleeve that matches the ejector pin.

[0010] Furthermore, the moving mold base is provided with a through ejector pin hole, which is used to cooperate with the ejector pin to push the ejector plate for ejection displacement. A reset component is also provided between the ejector plate and the moving mold base, and the reset component is a cylindrical helical compression spring.

[0011] Furthermore, the ejector plate uses a push rod structure to synchronously drive the outer sliding block to move away from the moving mold core, and the displacement priority of the outer sliding block is greater than that of the inner sliding block.

[0012] Furthermore, the axial direction of the inclined slide is inclined to the axial direction of the product.

[0013] Furthermore, the top of the ejector pin is located at the bottom port of the product, and there are eight ejector pins, which are evenly distributed at equal angles. There are also eight sprue outlets.

[0014] Compared to existing technologies, the advantages of this application are:

[0015] This application employs a sprue design with evenly spaced gates at equal angles on the fixed mold core. This design allows the molten plastic to flow evenly to all parts of the cavity after exiting the sprue bushing. This avoids problems such as localized material shortages and inconsistent density caused by uneven melt distribution, reduces the risk of surface scratches due to uneven stress, ensures the overall appearance quality of the product, and improves the product's yield rate. At the same time, eight ejector pins evenly spaced at equal angles act on the bottom port of the product, providing a uniformly distributed ejection force during ejection. This effectively prevents deformation and scratches caused by excessive local stress, ensuring that the product smoothly leaves the cavity during ejection, further maintaining the product's appearance integrity and structural stability. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the front structure of this application;

[0017] Figure 2 This is a schematic diagram of the bottom structure of this application;

[0018] Figure 3 This is a schematic diagram of the internal structure of this application;

[0019] Figure 4 This is a cross-sectional structural diagram of this application;

[0020] Figure 5 This is a partial structural diagram of the fixed mold core and the moving mold core proposed in this application;

[0021] Figure 6 This is a schematic diagram of the structure of the inner positioning block and ejector pin moving upwards to remove material as proposed in this application;

[0022] Figure 7 This is a schematic diagram of the product structure proposed in this application.

[0023] Explanation of the labels in the diagram:

[0024] 1. Fixed mold base; 2. Fixed mold plate; 21. Fixed mold core; 211. Sprue; 3. Moving mold plate; 31. Moving mold core; 311. Angled slide; 4. Moving mold base; 41. Ejector pin hole; 5. Ejector plate; 51. Side slide block; 6. Outer sliding block; 7. Inner sliding block; 71. Angled bar; 72. Side slide block; 8. Product; 9. Ejector pin. Detailed Implementation

[0025] The embodiments will be described clearly and completely with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments in this application without creative effort are within the scope of protection of this application.

[0026] Example 1:

[0027] This utility model provides an injection mold for preventing material ejection and tearing. Please refer to [link / reference]. Figure 1 - Figure 7 8, used for injection molding of barrel-shaped products, including a fixed mold part and a moving mold part, as detailed below:

[0028] The fixed mold part includes a fixed mold base 1, a fixed template 2, and a fixed mold core 21. The fixed template 2 is installed on the fixed mold base 1. A first positioning groove for installing the fixed mold core 21 is provided on one side surface of the fixed template 2. The fixed mold core 21 is positioned and fixed on the fixed template 2 through the first positioning groove. The inner contour shape of the fixed mold core 21 is adapted to the outer shape of the product 8 to form the outer surface shape of the barrel-shaped product.

[0029] The fixed mold base 1 and the fixed mold plate 2 are provided with through sprue sleeves. The fixed mold core 21 is provided with multiple sets of sprue gates 211. Several sprue gates 211 are evenly distributed in the sprue gates 211 at equal angles. The input end of the sprue gate 211 is connected to the output end of the sprue sleeve. The output end of the sprue gate 211 extends to the bottom of the fixed mold core 21 and is located at the top of the port of the product 8.

[0030] The moving mold part includes a moving mold base 4, a moving mold plate 3 and a moving mold core 31. The moving mold plate 3 is mounted on the moving mold base 4, and a material ejector plate 5 is slidably connected between the moving mold base 4 and the moving mold plate 3.

[0031] The moving mold plate 3 is provided with a second positioning groove for installing the moving mold core 31. The moving mold core 31 is fixed in the second positioning groove. Four sets of inner sliding blocks 7 are also slidably connected in the circumferential direction of the moving mold core 31. The sliding direction of the four sets of inner sliding blocks 7 is inclined to the axial direction of the product 8. The outer contour formed by the moving mold core 31 and the four sets of inner sliding blocks 7 after being engaged is adapted to the internal shape of the product 8. The moving mold plate 3 is also slidably connected with four sets of outer sliding blocks 6 in the direction parallel to its end face. The four sets of outer sliding blocks 6 slide relative to each other in pairs. The inner contour formed by the four sets of outer sliding blocks 6 after being engaged is adapted to the external shape of the product 8. After the fixed mold core 21, the moving mold core 31, the inner sliding blocks 7 and the outer sliding blocks 6 are fully engaged, a complete cavity corresponding to the product 8 is formed.

[0032] The bottom of each inner sliding block 7 is fixed with a slant rod 71. The moving mold core 31 is provided with a slant groove 311 that matches the slant rod 71. The bottom end of the slant rod 71 is fixed with a side slide block 72. The ejector plate 5 is fixed with a side slide seat 51 that matches the side slide block 72. Several ejector pins 9 are also fixed on the ejector plate 5. The moving mold core 31 is provided with an ejector pin sleeve that matches the ejector pin 9.

[0033] It should be noted that the moving mold base 4 is provided with a through ejector pin hole 41. The ejector pin hole 41 is used to cooperate with the ejector pin to push the ejector plate 5 to perform ejection displacement. A reset component is also provided between the ejector plate 5 and the moving mold base 4. The reset component is a cylindrical helical compression spring.

[0034] Furthermore, the ejector plate 5 uses the push rod structure to synchronously drive the outer sliding block 6 to move away from the moving mold core 31, and the displacement priority of the outer sliding block 6 is greater than that of the inner sliding block 7.

[0035] Among them, the axial direction of the inclined slide 311 is inclined to the axial direction of the product 8, the top of the ejector pin 9 is set at the bottom port of the product 8, there are eight ejector pins 9, and the eight ejector pins 9 are evenly distributed at equal angles, and there are eight sprue nozzles 211.

[0036] In actual use, the injection molding machine drives the moving mold part to move towards the fixed mold part. The moving mold base 4 drives the moving platen 3 and its components to gradually approach the fixed platen 2, finally realizing the mold closing action. At this time, the fixed mold core 21, the moving mold core 31, the inner sliding block 7, and the outer sliding block 6 are completely aligned, forming a complete cavity corresponding to the product 8. The components fit tightly together to ensure the sealing and shape accuracy of the cavity, preparing for injection molding.

[0037] Molten plastic is injected through the injection nozzle of the injection molding machine into the sprue bushing that runs through the fixed mold base 1 and the fixed mold plate 2. The melt is evenly distributed through the sprue bushing to the sprue nozzles 211 that are evenly distributed at equal angles on the fixed mold core 21. Then, it enters the cavity space formed by the various components from the output end of the sprue nozzles 211. The melt gradually fills and cools and solidifies in the cavity, eventually forming the shape of the barrel-shaped product 8. In this process, the even distribution of the sprue nozzles 211 ensures that the melt fills the cavity evenly, reduces the injection pressure, and avoids localized quality problems in the product.

[0038] After injection molding is completed, the injection molding machine drives the moving mold part to separate from the fixed mold part and begins the mold opening action. First, the moving mold base 4 drives the moving mold plate 3 and other components to move backward together. During this process, the ejector plate 5 is pushed out by the ejector roller and moves relative to the moving mold base 4. Through the push rod structure, it preferentially drives the outer sliding block 6 to move away from the moving mold core 31. Since the displacement priority of the outer sliding block 6 is greater than that of the inner sliding block 7, the outer sliding block 6 slides outward and separates from the outside of the product 8 first to avoid interference with the shape.

[0039] As the mold opening process continues, after a certain stroke, the ejector device of the injection molding machine drives the ejector pin through the ejector pin hole 41 on the moving mold base 4, and the ejector pin pushes the ejector plate 5 to perform ejection displacement. When the ejector plate 5 moves, on the one hand, through the cooperation of the side slide block 51 fixed on it and the side slide block 72 at the bottom of the inner slide block 7, the inclined rod 71 is driven to slide in the inclined slide groove 311, thereby driving the inner slide block 7 to slide in the set inclined direction, realizing the demolding of the internal structure of the product 8; on the other hand, the ejector pin 9 on the ejector plate 5 applies a uniform ejection force to the bottom port of the product 8, assisting the product 8 to completely eject from the cavity. Throughout the ejection process, the components work together in a reasonable sequence and manner, and through the uniform ejection force and the ingenious demolding structure, the product 8 is effectively prevented from being scratched during the demolding process.

[0040] After product 8 is demolded, the ejector device of the injection molding machine drives the ejector roller to retract and reset. Under the action of the reset assembly composed of cylindrical spiral compression springs, the ejector plate 5 slides back to its initial position along the sliding connection structure between the moving mold base 4 and the moving mold plate 3. At the same time, the inner sliding block 7 slides back inward under the action of the corresponding reset structure, such as a spring or other elastic element, depending on the actual design. The outer sliding block 6 also returns to its initial position through the corresponding reset mechanism, which can also be achieved by using springs or other means. All components are restored to their state before mold closing, preparing for the next injection molding.

[0041] This application employs a design with evenly distributed sprue gates 211 on the fixed mold core 21, which allows the molten plastic to flow evenly to all parts of the cavity after exiting from the sprue bushing. This avoids problems such as localized material shortages and inconsistent density caused by uneven melt distribution. This ensures relatively uniform force on all parts of the product during demolding, fundamentally reducing the risk of surface scratches caused by uneven force, guaranteeing the overall appearance quality of the product, and improving the product's yield rate. Through the ingenious design of the outer sliding block 6 and the inner sliding block 7, and their specific action sequence—the outer sliding block 6 first slides outward to detach from the outside of the product 8, and then the inner sliding block 7 slides in an inclined direction to demold the internal structure of the product—interference and jamming between components and the product during demolding are effectively avoided. This orderly demolding method, adapted to the product's shape characteristics, significantly reduces friction and scratching between the product surface and mold components, ensuring smooth demolding of the product, whether external or internally complex, with an intact surface, thus improving the product's demolding quality.

[0042] Meanwhile, eight ejector pins 9, evenly distributed at equal angles, act on the bottom port of the product 8, providing a uniformly distributed ejection force during ejection. Compared to the uneven ejection force in traditional molds, this design effectively prevents deformation and tearing of the product due to excessive local stress, ensuring that the product smoothly leaves the cavity during ejection, further maintaining the product's appearance integrity and structural stability.

[0043] The above description is only the best implementation method adopted in this application in combination with current practical needs, but the scope of protection of this application is not limited thereto.

Claims

1. An injection mold for preventing material ejection and tearing, used for injection molding barrel-shaped products (8), characterized in that, It includes the fixed mold part and the moving mold part, as detailed below: Fixed mold part: includes fixed mold base (1), fixed template (2) and fixed mold core (21). The fixed template (2) is installed on the fixed mold base (1). A first positioning groove for installing the fixed mold core (21) is provided on one side surface of the fixed template (2). The fixed mold core (21) is positioned and fixed on the fixed template (2) through the first positioning groove. The inner contour shape of the fixed mold core (21) is adapted to the outer shape of the product (8) to form the outer surface shape of the barrel-shaped product. The fixed mold base (1) and the fixed mold plate (2) are provided with through sprue sleeves. The fixed mold core (21) is provided with multiple sets of sprue gates (211). Several sprue gates (211) are evenly distributed in the sprue gates (211) at equal angles. The input end of the sprue gate (211) is connected to the output end of the sprue sleeve. The output end of the sprue gate (211) extends to the bottom of the fixed mold core (21) and is set at the top of the port of the product (8). The moving mold part includes a moving mold base (4), a moving template (3) and a moving mold core (31). The moving template (3) is mounted on the moving mold base (4). A stripper plate (5) is also slidably connected between the moving mold base (4) and the moving template (3). The moving template (3) is provided with a second positioning groove for installing the moving mold core (31). The moving mold core (31) is fixed in the second positioning groove. The moving mold core (31) is also slidably connected with four sets of inner sliding blocks (7) in the circumferential direction. The sliding direction of the four sets of inner sliding blocks (7) is inclined to the axial direction of the product (8). The outer contour formed by the moving mold core (31) and the four sets of inner sliding blocks (7) after being engaged is adapted to the internal shape of the product (8). The moving template (3) is also slidably connected with four sets of outer sliding blocks (6) in the direction parallel to its end face. The four sets of outer sliding blocks (6) slide relative to each other in pairs. The inner contour formed by the four sets of outer sliding blocks (6) after being engaged is adapted to the external shape of the product (8). The fixed mold core (21), the moving mold core (31), the inner sliding blocks (7) and the outer sliding blocks (6) are fully engaged to form a complete cavity corresponding to the product (8). The bottom of each inner sliding block (7) is fixed with a slant rod (71). The moving mold core (31) is provided with a slant groove (311) that matches the slant rod (71). The bottom end of the slant rod (71) is fixed with a side slide block (72). The ejector plate (5) is fixed with a side slide seat (51) that matches the side slide block (72). The ejector plate (5) is also fixed with a number of ejector pins (9). The moving mold core (31) is provided with an ejector pin sleeve that matches the ejector pin (9).

2. The injection mold for preventing material ejection and tearing according to claim 1, characterized in that, The moving mold base (4) is provided with a through ejector pin hole (41). The ejector pin hole (41) is used to cooperate with the ejector pin to push the ejector plate (5) to perform ejection displacement. A reset component is also provided between the ejector plate (5) and the moving mold base (4). The reset component is a cylindrical helical compression spring.

3. The injection mold for preventing material ejection and tearing according to claim 1, characterized in that, The ejector plate (5) uses a push rod structure to synchronously drive the outer sliding block (6) to move away from the moving mold core (31), and the displacement priority of the outer sliding block (6) is greater than that of the inner sliding block (7).

4. The injection mold for preventing material ejection and tearing according to claim 1, characterized in that, The axial direction of the inclined slide (311) is inclined to the axial direction of the product (8).

5. The injection mold for preventing material ejection and tearing according to claim 1, characterized in that, The top of the ejector pin (9) is located at the bottom port of the product (8). There are eight ejector pins (9), and the eight ejector pins (9) are evenly distributed at equal angles. There are also eight sprue nozzles (211).

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