Anti-shrinkage injection mold for thick-walled products
By using a "田"-shaped mold cavity distribution and injection molding block design, the shrinkage problem in the injection molding process of thick-walled products was solved, achieving uniform filling of the plastic melt and improving product quality and production efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-21
- Publication Date
- 2026-08-04
AI Technical Summary
Thick-walled products are prone to shrinkage during injection molding due to the uneven cooling rate of the internal plastic melt caused by their large wall thickness. This results in defects such as surface depressions and internal shrinkage cavities, which are difficult to solve effectively using traditional methods.
The mold cavity is designed with four "田" (field) shaped distributions, combined with a central "一" (one) shaped channel and injection tube design. The diameter of the arc-shaped section of the injection insert gradually decreases, and the long waist-shaped outlet structure forms a scientific melt transfer path, ensuring that the plastic melt fills the mold cavity evenly.
It achieves efficient distribution and transport of molten plastic in multi-cavity molds, reduces product shrinkage differences, improves product consistency and quality, increases production efficiency, and reduces production costs.
Smart Images
Figure CN224588487U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of injection molds, and particularly relates to an anti-shrinkage injection mold for thick-wall products. Background Art
[0002] In the production field of plastic products, thick-wall products are widely used in many industries such as automotive parts, home appliance shells, and industrial equipment shells due to their high strength, high rigidity and other characteristics. However, in the injection molding process, due to the large wall thickness of thick-wall products, the cooling speed of the internal plastic melt is inconsistent, and shrinkage is extremely likely to occur, resulting in defects such as depressions on the product surface and shrinkage holes inside, seriously affecting the appearance quality and service performance of the product.
[0003] At present, when traditional injection molds deal with the shrinkage problem of thick-wall products, they mostly adopt conventional methods such as increasing the holding time and increasing the injection pressure, but the effects of these methods are limited and it is difficult to fundamentally solve the shrinkage defects; some molds improve the filling and cooling conditions by optimizing the layout of the gating system. However, when dealing with thick-wall products in a multi-cavity mold with a specific cavity distribution, it is impossible to accurately control the flow and filling of the plastic melt, resulting in different shrinkage degrees of products in each cavity, low product qualification rate, and it is difficult to meet the market's production demand for high-quality thick-wall products. Therefore, it is urgent to develop a new type of injection mold to effectively solve the shrinkage problem of thick-wall products and improve product quality and production efficiency. Summary of the Utility Model
[0004] In view of the deficiencies in the background art, the utility model provides an anti-shrinkage injection mold for thick-wall products.
[0005] The technical solution adopted by the utility model is: an anti-shrinkage injection mold for thick-wall products, including an upper template, a moving template, a static template, a lower mold base, an upper mold core and a lower mold core. The upper mold core and the lower mold core are arranged between the static template and the moving template, and there is a mold cavity for forming products between the upper mold core and the lower mold core. An injection port is arranged on the upper template. It also includes an injection pipe and an injection insert. There are four mold cavities, distributed in a "field" shape. A connection port is arranged in the center of the upper mold core and the lower mold core, and a "one" - shaped channel is arranged between the upper mold core and the lower mold core. One end of the injection pipe is connected to the connection port and communicated with the "one" - shaped channel, and the other end is connected to the injection port. Installation ports for installing injection inserts are arranged on both sides of the "one" - shaped channel.
[0005] The injection insert includes a left insert and a right insert. An injection channel is arranged between the left insert and the right insert. The injection channel includes an inlet communicated with the "one" - shaped channel, an outlet communicated with the mold cavity, and an arc section connecting the inlet and the outlet. The diameter of the arc section gradually decreases from the inlet to the outlet, and the outlet is of a long waist-shaped structure.
[0006] Further, on both sides of one end of the injection molding pipe connected to the connection port, there are gaps communicating with the "one" - shaped channel.
[0007] Further, the length of the outlet is 4 - 5 mm, and the width is 0.5 - 1 mm.
[0008] Further, the inlet is connected to the "one" - shaped channel through a communication channel.
[0009] Further, there are mutually - cooperating positioning steps provided in the installation port and on the injection molding insert.
[0010] The beneficial effects of the present utility model are as follows: Firstly, the mold cavity adopts a design with four "field" - shaped distributions. With the settings of the central connection port, the "one" - shaped channel, and the injection molding pipe, a scientific and reasonable melt transmission path is formed. Compared with traditional molds, it can achieve efficient distribution and transportation of plastic melt in a multi - cavity mold, ensure the balance of feeding for each mold cavity, thereby reducing the product shrinkage difference caused by uneven feeding, and improving the consistency of products.
[0011] Secondly, the injection molding channel between the left insert and the right insert in the injection molding insert is ingeniously designed. The diameter of its arc - shaped section gradually decreases from the inlet to the outlet, which can produce a certain pressure - boosting effect on the plastic melt, enabling the melt to maintain a stable and continuous pressure during the process of filling the mold cavity, helping to reduce the shrinkage space during the cooling process of the melt; at the same time, the outlet adopts a long - waist - shaped structure, which can optimize the flow rate and flow direction of the melt entering the mold cavity, allowing the melt to fill the mold cavity more evenly, avoiding phenomena such as local under - filling or over - filling, and further reducing the generation probability of shrinkage defects such as surface depressions and internal shrinkage holes of the product.
[0012] In addition, the installation ports provided on both sides of the "one" - shaped channel facilitate the installation and disassembly of the injection molding insert, making it convenient to replace injection molding inserts of different specifications according to the requirements of different thick - wall products during the production process. This improves the versatility and adaptability of the mold, reduces production costs, and also provides convenience for quickly adjusting the production process and optimizing product quality, significantly enhancing the production efficiency and quality level of thick - wall products, and meeting the market's production demand for high - quality thick - wall products.
[0013] In addition to the purposes, features, and advantages described above, the present utility model has other purposes, features, and advantages.
[0014] Next, the present utility model will be further described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 It is a structural schematic diagram of the present utility model.
[0016] Figure 2This is a cross-sectional schematic diagram of the present invention.
[0017] Figure 3 This is a structural view of the lower mold core and injection tube.
[0018] Figure 4 for Figure 3 Enlarged diagram of point A in the middle.
[0019] Figure 5 This is a schematic diagram of the explosion of the lower mold core and injection tube.
[0020] Figure 6 This is a schematic diagram of the upper mold core and the lower mold core.
[0021] Figure 7 This is an exploded view of an injection-molded insert.
[0022] Figure 8 This is an exploded view of the lower mold core and the injection insert. Detailed Implementation
[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0024] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.
[0025] This utility model provides a shrinkage-resistant injection mold for thick-walled products.
[0026] In this embodiment, refer to Figure 1-8, The shrinkage-proof injection mold for thick-walled products includes an upper template 1, a moving template 2, a static template 22, a lower mold base 3, an upper mold core 4 and a lower mold core 5. The upper and lower mold cores are arranged between the static and moving templates, and there is a mold cavity 6 for molding the product between the upper and lower mold cores. An injection port 7 is provided on the upper template. It also includes an injection pipe 8 and an injection insert 9. The mold cavity 6 is four in number and is distributed in a "field" shape. A connection port 10 is provided in the center of the upper and lower mold cores, and a "one" - shaped channel 11 is provided between the upper and lower mold cores. One end of the injection pipe 8 is connected to the connection port and is communicated with the "one" - shaped channel 11, and the other end is connected to the injection port. Installation ports 12 for installing the injection inserts are provided on both sides of the "one" - shaped channel; The injection insert includes a left insert 13 and a right insert 14. An injection channel 21 is provided between the left insert 13 and the right insert 14. The injection channel 21 includes an inlet 15 communicated with the "one" - shaped channel, an outlet 16 communicated with the mold cavity, and an arc section 17 connecting the inlet and the outlet. The diameter of the arc section 17 gradually decreases from the inlet to the outlet, and the outlet is of a long waist - shaped structure.
[0027] In the above technical solution, the mold cavities are distributed in a "field" shape, and with the structural design of the central connection port, the "one" - shaped channel, the injection pipe and the injection insert, a unique plastic melt delivery path is constructed. The design of the gradually changing diameter of the arc section and the long waist - shaped outlet of the injection insert changes the resistance and pressure distribution of the plastic melt during the flow process. The melt flows in from the inlet, accelerates in the arc section with a gradually decreasing diameter, and when it reaches the long waist - shaped outlet, it can uniformly fill the mold cavity at a specific flow rate and pressure. Moreover, the long waist - shaped outlet can adjust the flow direction and coverage range of the melt.
[0028] The "field" - shaped distribution of the mold cavities enables multi - cavity simultaneous injection, improving production efficiency; the unique injection channel structure ensures that the plastic melt fills the mold cavity evenly and stably, effectively avoiding local under - filling or over - filling caused by uneven melt flow, reducing shrinkage defects such as surface depressions and internal shrinkage holes of the product, and significantly improving the product quality and qualification rate.
[0029] Specifically, gaps 18 communicated with the "one" - shaped channel are provided on both sides of the end of the injection pipe connected to the connection port.
[0030] In this embodiment, the gaps provided on both sides of the end of the injection pipe connected to the connection port are used to communicate with the "one" - shaped channel.
[0031] Specifically, the length of the outlet is 4 - 5 mm and the width is 0.5 - 1 mm.
[0032] In this embodiment, the appropriate outlet size ensures that the plastic melt can provide a reasonable amount of shrinkage compensation for thick-walled products during the filling and cooling process, preventing shrinkage cavities from forming inside the product due to insufficient shrinkage compensation, or product deformation due to excessive shrinkage compensation, thereby effectively improving the internal structure and appearance quality of the product.
[0033] Specifically, the entrance is connected to the "I"-shaped channel through the connecting channel 19; the mounting port and the injection-molded insert are provided with mutually cooperating positioning steps 20.
[0034] In this embodiment, the positioning steps that cooperate with each other inside the mounting port and on the injection-molded insert utilize the principle of mechanical positioning to ensure that the injection-molded insert can be accurately and stably installed inside the mounting port during the installation process, thus ensuring the relative positional accuracy of the injection channel of the injection-molded insert and other components.
[0035] Attention all technical personnel: Although this utility model has been described according to the specific embodiments above, the concept of this utility model is not limited to this utility model. Any modification that utilizes the concept of this utility model will be included within the scope of protection of this patent right.
Claims
1. A shrinkage-resistant injection mold for thick-walled products, comprising an upper mold plate, a moving mold plate, a stationary mold plate, a lower mold base, an upper mold core, and a lower mold core, wherein the upper mold core and the lower mold core are disposed between the stationary mold plate and the moving mold plate, and a mold cavity for molding the product is provided between the upper mold core and the lower mold core, and an injection port is provided on the upper mold plate, characterized in that: It further includes an injection molding pipe and injection molding inserts. There are four mold cavities, which are distributed in a "field" shape. A connection port is provided in the center of the upper mold core and the lower mold core. A "one" - shaped channel is provided between the upper mold core and the lower mold core. One end of the injection molding pipe is connected to the connection port and is communicated with the "one" - shaped channel, and the other end is connected to the injection port. Installation ports for installing the injection molding inserts are provided on both sides of the "one" - shaped channel; The injection molding insert includes a left insert and a right insert. An injection molding channel is provided between the left insert and the right insert. The injection molding channel includes an inlet communicated with the "one" - shaped channel, an outlet communicated with the mold cavity, and an arc section connecting the inlet and the outlet. The diameter of the arc section gradually decreases from the inlet to the outlet, and the outlet is of a long - waist - shaped structure.
2. The anti-shrinkage injection mold for thick-walled products according to claim 1, characterized in that: On both sides of the end of the injection molding pipe connected to the connection port, there are gaps communicated with the "one" - shaped channel.
3. The anti-shrinkage injection mold for thick-walled products according to claim 1, characterized in that: The length of the outlet is 4 - 5 mm, and the width is 0.5 - 1 mm.
4. The anti-shrinkage injection mold for thick-walled products according to claim 1, characterized in that: The inlet is communicated with the "one" - shaped channel through a communication channel.
5. The anti-shrinkage injection mold for thick-walled products according to claim 1, characterized in that: Mutually - matching positioning steps are provided in the installation port and on the injection molding insert.