A small runner injection molding mold

Abstract

This utility model discloses a small-sized runner injection molding die, including a die body, which includes an upper die and a lower die. The upper die includes an upper mounting plate, a strength retaining block, and an upper template. The lower die includes a lower template and a lower mounting plate. The strength retaining block is U-shaped. The strength retaining block and the upper template are sequentially bolted to the bottom of the upper mounting plate from top to bottom. The runner assembly of this utility model is installed between the strength retaining block, the upper mounting plate, and the upper template and contacts the die through a positioning pin and a riser pad. The extended nozzle installed at its bottom extends into the upper template. The overall structure is relatively simple, while minimizing the distance between the designed surfaces and reducing the volume. This not only allows for simple filling balance adjustment but also provides more stable quality. At the same time, the length of the first runner and the gate is shortened, and excess runners are reduced, which not only shortens the injection molding time but also reduces the defect rate and the amount of resin used, saving resources and costs.

Description

Technical Field

[0001] This utility model belongs to the field of mold technology, specifically relating to a small runner injection molding mold. Background Technology

[0002] Traditionally, injection molding has used two main runner systems: cold runner and hot runner. A cold runner system delivers molten resin into the mold cavity through a gate runner system, starting from the nozzle tip of the injection molding machine and passing through the mold cavity. The product is then filled into the mold cavity by establishing runners within the cavity. For example... Figure 1-3 The image shows a mold, product, runner, and gate for a single-cavity, 8-stage cold runner system. It's evident that more resin is used in the gate and runner compared to the resin used in product manufacturing. This presents the following problems: In multi-cavity molds, improper spacing between runners can lead to poor quality; resin cooling and solidification begin from the moment molten resin is injected, necessitating unnecessarily high resin temperature, injection pressure, and injection speed settings, thus contributing to quality issues; and the use of excessive material in areas beyond the desired product (runner and gate) increases costs. Wasteful processes exist because a large amount of resin is used in parts outside the product, leading to longer molding and cooling times, resulting in additional cost waste. Furthermore, the increased resin usage outside the product necessitates a larger forming tonnage, requiring larger molding machines and molds, again contributing to cost waste. In the hot runner method, the resin is kept in a molten state within the mold, and the product is filled from near the mold cavity. However, this method also presents problems such as increased mold costs, more complex mold design, and the need for initial investment. Therefore, a small-scale runner injection molding mold is designed to address these technical shortcomings. Utility Model Content

[0003] (1) Technical problems to be solved

[0004] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a small runner injection molding die to solve the above-mentioned technical problems.

[0005] (2) Technical solution

[0006] To solve the above-mentioned technical problems, this utility model provides a small-sized runner injection molding die, including a die body, which includes an upper die and a lower die. The upper die includes an upper mounting plate, a strength retaining block, and an upper template. The lower die includes a lower template and a lower mounting plate. The strength retaining block is U-shaped. The strength retaining block and the upper template are sequentially bolted to the bottom of the upper mounting plate from top to bottom. The lower template is bolted to the top center of the lower mounting plate. A runner assembly is provided inside the strength retaining block. The top center of the upper template has a mounting groove that mates with the runner assembly. The bottom wall of the mounting groove has a gate that penetrates the bottom of the upper template. A punch is integrally formed at the bottom of the upper template and at a position corresponding to the gate. Multiple molding cavities are provided at the top of the lower template and at a position corresponding to the punch. Adjacent molding cavities are connected by a first runner.

[0007] Preferably, the upper mounting plate has a mounting hole in the middle, and a gate sleeve is bolted inside the mounting hole, the gate sleeve being connected to the runner assembly.

[0008] Furthermore, the runner assembly includes a support plate located in the middle of the strength retaining block. The top center of the support plate is connected to the gate sleeve. The interior of the support plate is provided with a U-shaped second runner. The middle of the second runner is connected to the gate sleeve. An extension nozzle is bolted to the lower surface of the support plate at a position corresponding to both ends of the second runner.

[0009] Furthermore, the top four corners and bottom four corners of the support plate are provided with first positioning grooves, and positioning pins are installed inside the first positioning grooves. The bottom of the upper mounting plate and the top of the upper template are provided with second positioning grooves that are adapted to the four positioning pins. The end of the positioning pin away from the first positioning groove is located inside the second positioning groove.

[0010] Furthermore, riser pads are fixedly connected to the middle of the upper and lower surfaces of the bearing plate, and the upper and lower riser pads are in contact with the upper mounting plate and the upper template.

[0011] Furthermore, the end of the extended nozzle furthest from the support plate is located inside the mounting groove. The discharge nozzle at the bottom of the extended nozzle is connected to the gate. A contact sleeve is installed inside the discharge nozzle. A compartment is formed between the contact sleeve and the bottom of the discharge nozzle. A resin gel layer is formed inside the compartment.

[0012] Furthermore, heaters are embedded inside the support plate and on both sides of the second flow channel. A clearance is provided at one end of the support plate between the two heaters, and a thermocouple sensor is installed inside the clearance.

[0013] (3) Beneficial effects

[0014] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0015] The runner assembly of this invention is installed between the strength retaining block, the upper mounting plate, and the upper template, and contacts the mold through the positioning pin and the riser pad. The extended nozzle installed at the bottom extends into the upper template. The overall structure is relatively simple, while minimizing the distance between the designed surfaces and reducing the volume. This not only makes it easier to adjust the filling balance, but also makes the quality more stable. At the same time, the length of the first runner and the gate are shortened and the excess runner is reduced, which not only shortens the injection molding time, but also reduces the defect rate and the amount of resin used, saving resources and costs. Furthermore, the mold size is smaller and the required molding machine size is smaller, which greatly reduces costs. Attached Figure Description

[0016] Figure 1 A schematic diagram of the main sectional view of a mold for an existing single-cavity, 8-number cold runner system;

[0017] Figure 2 This is a schematic diagram of the right-side cross-sectional structure of a mold with an existing single-cavity, 8-number cold runner system.

[0018] Figure 3 A schematic diagram of the product structure for an existing single-diaphragm cavity 8-scan cold runner system;

[0019] Figure 4 A schematic diagram of the runner, gate, and product structure for an existing single-cavity 8-slot cold runner system;

[0020] Figure 5 This is a schematic diagram of the front cross-sectional structure of the mold with 8 numbers of a single membrane cavity in this utility model;

[0021] Figure 6 This is a schematic diagram of the right cross-sectional structure of the mold with a single diaphragm cavity for selecting 8 numbers in this utility model;

[0022] Figure 7 This is a top view of the mold for single-cavity 8-number acquisition in this utility model without the upper mounting plate.

[0023] Figure 8 This is a schematic diagram of the main cross-sectional view of the H-shaped flow channel assembly of the single-cavity 8-number mold in this utility model;

[0024] Figure 9 This is a right-side sectional view of the H-shaped flow channel assembly of the single-cavity 8-number mold in this utility model.

[0025] Figure 10 This is a schematic diagram of the right side of the Type I flow channel assembly in this utility model.

[0026] The labels in the attached diagram are as follows: 1. Upper mounting plate; 2. Strength retaining block; 3. Upper template; 4. Lower template; 5. Lower mounting plate; 6. Sprue sleeve; 7. Support plate; 8. Positioning pin; 9. Riser pad; 10. Mounting groove; 11. Extended nozzle; 12. Sprue; 13. First runner; 14. Molding cavity; 15. Second runner; 16. Contact sleeve; 17. Resin gel layer; 18. Heater; 19. Thermocouple sensor. Detailed Implementation

[0027] This specific embodiment is a small-scale runner injection molding die, the structural schematic diagram of which is shown below. Figures 5-10 As shown, the mold includes a mold body, which includes an upper mold and a lower mold. The upper mold includes an upper mounting plate 1, a strength retaining block 2, and an upper template 3. The lower mold includes a lower template 4 and a lower mounting plate 5. The strength retaining block 2 is U-shaped. The strength retaining block 2 and the upper template 3 are bolted to the bottom of the upper mounting plate 1 from top to bottom. The lower template 4 is bolted to the top center of the lower mounting plate 5. A runner assembly is provided inside the strength retaining block 2. The top center of the upper template 3 is provided with a mounting groove 10 that cooperates with the runner assembly. The bottom wall of the mounting groove 10 is provided with a gate 12 that penetrates the bottom of the upper template 3. A punch is integrally formed at the bottom of the upper template 3 and at a position corresponding to the gate 12. Multiple forming cavities 14 are provided at the top of the lower template 4 and at a position corresponding to the punch. Adjacent forming cavities 14 are connected by a first runner 13.

[0028] Specifically, when installing the runner assembly, a strength retaining block 2 and a matching upper mounting plate 1 and upper template 3 are prefabricated as needed. The strength retaining block 2 is then bolted to the upper template 3, and the runner assembly is installed inside the strength retaining block 2. Finally, the upper mounting plate 1 is installed on the strength retaining block 2, so that the runner assembly is located between the upper mounting plate 1, the strength retaining block 2, and the upper template 3. The strength retaining block 2 can protect the runner assembly and prevent damage to the runner assembly when the mold is closed. The length of the gate 12 is shorter than that of the gate 12 in the existing cold runner system, and the length of the first runner 13 is also significantly shortened. This not only saves raw materials but also reduces the mold volume, thereby saving initial investment costs.

[0029] In addition, the upper mounting plate 1 has a mounting hole in the middle, and a sprue sleeve 6 is bolted inside the mounting hole. The sprue sleeve 6 is connected to the runner assembly. When the whole assembly is completed and put into use, the molten resin enters the runner assembly through the sprue sleeve 6. The resin in the mold is always kept in a molten state, which can also be said to be the same state as the nozzle of the injection molding machine extending into the mold.

[0030] In addition, the runner assembly includes a support plate 7, which is located in the middle of the strength retaining block 2. The top center of the support plate 7 is connected to the sprue sleeve 6. The interior of the support plate 7 is provided with a U-shaped second runner 15, the middle of which is connected to the sprue sleeve 6. An extension nozzle 11 is bolted to the lower surface of the support plate 7 at positions corresponding to the two ends of the second runner 15. The support plate 7 can be manufactured as needed so that the second runner 15 inside can form an H-shaped or I-shaped structure, i.e., a single mold with 8 outlets or a single mold with 4 outlets. The top four corners and bottom four corners of the support plate 7 are also provided with extension nozzles 11. Each of the four mounting plates is provided with a first positioning groove, and a positioning pin 8 is installed inside the first positioning groove. The bottom end of the upper mounting plate 1 and the top end of the upper template 3 are each provided with a second positioning groove that matches the four positioning pins 8. The end of the positioning pin 8 furthest from the first positioning groove is located inside the second positioning groove. Vertical pipe pads 9 are fixedly connected to the middle of the upper surface and the middle of the lower surface of the bearing plate 7. The upper and lower vertical pipe pads 9 are in contact with the upper mounting plate 1 and the upper template 3 respectively. The positioning pins 8 are the part of the bearing plate 7 that directly contacts the mold. Although there is a heat source inside the bearing plate 7, the contact area with the mold is very small. This will not affect the mold temperature; at the same time, the support plate 7 contacts the mold through the riser pad 9, and the riser pad 9 is made of heat-insulating material, so it will not affect the mold temperature; the end of the extended nozzle 11 away from the support plate 7 is located inside the mounting groove 10, and the discharge nozzle at the bottom of the extended nozzle 11 is connected to the gate 12. A contact sleeve 16 is installed inside the discharge nozzle, and a compartment is formed between the contact sleeve 16 and the bottom end of the discharge nozzle. A resin gel layer 17 is formed inside the compartment; by installing the contact sleeve 16 inside the discharge nozzle and forming a compartment, the resin at the front end of the discharge nozzle is kept in a constant state. To prevent stringing, the contact sleeve 16 is designed to be in a gelled state. It can also be shaped to accommodate different resins, thus preventing stringing regardless of the resin being used. The extended nozzle 11 is located inside the mounting groove 10, eliminating the need for additional flow channels on the upper mold plate 3 for resin injection. This allows for a smaller mold and molding machine, reducing unnecessary costs. Furthermore, the length of the extended nozzle 11 can be adjusted according to the thickness of the upper mold plate 3, enabling it to be positioned directly below the design surface. When the extended nozzle 11 injects resin near the design surface, the absence of excess resin flow paths allows for immediate filling of the design surface, shortening injection time and improving quality stability. Additionally, the smaller gate 12 and second runner 15 reduce cooling time, further contributing to quality stability and shorter molding time, thus minimizing cost waste in all aspects.

[0031] In addition, heaters 18 are embedded inside the support plate 7 and on both sides of the second flow channel 15. A clearance is provided at one end of the support plate 7 between the two heaters 18, and a thermocouple sensor 19 is installed inside the clearance. The heaters 18 and thermocouple sensor 19 are existing technologies and will not be described in detail here.

[0032] All technical features in this embodiment can be freely combined according to actual needs.

[0033] The above embodiments are preferred implementations of this utility model. In addition, this utility model can also be implemented in other ways. Any obvious substitutions without departing from the concept of this technical solution are within the protection scope of this utility model.

Claims

1. A small runner injection molding mold comprising a mold body including an upper mold and a lower mold, characterized by, The upper mold includes an upper mounting plate (1), a strength retaining block (2), and an upper template (3). The lower mold includes a lower template (4) and a lower mounting plate (5). The strength retaining block (2) is U-shaped. The strength retaining block (2) and the upper template (3) are bolted to the bottom of the upper mounting plate (1) from top to bottom. The lower template (4) is bolted to the top center of the lower mounting plate (5). The strength retaining block (2) is provided with a flow channel assembly. The top center of the upper template (3) is provided with a mounting groove (10) that cooperates with the flow channel assembly. The bottom wall of the mounting groove (10) is provided with a gate (12) that penetrates the bottom of the upper template (3). The bottom of the upper template (3) is integrally formed with a punch at a position corresponding to the gate (12). The top of the lower template (4) is provided with multiple forming cavities (14) at a position corresponding to the punch. Adjacent forming cavities (14) are connected by a first flow channel (13).

2. The small-scale runner injection molding die according to claim 1, characterized in that: The upper mounting plate (1) has a mounting hole in the middle, and a gate sleeve (6) is bolted inside the mounting hole. The gate sleeve (6) is connected to the flow channel assembly.

3. A small runner injection molding tool according to claim 2, characterized in that: The flow channel assembly includes a support plate (7), which is located in the middle of the strength holding block (2). The top center of the support plate (7) is connected to the gate sleeve (6). The interior of the support plate (7) is provided with a U-shaped second flow channel (15), the middle of which is connected to the gate sleeve (6). An extension nozzle (11) is bolted to the lower surface of the support plate (7) at a position corresponding to both ends of the second flow channel (15).

4. A small runner injection molding tool according to claim 3, characterized in that: The bearing plate (7) has a first positioning groove at the top four corners and the bottom four corners. A positioning pin (8) is installed inside the first positioning groove. The bottom of the upper mounting plate (1) and the top of the upper template (3) are provided with a second positioning groove that matches the four positioning pins (8). The end of the positioning pin (8) away from the first positioning groove is located inside the second positioning groove.

5. A small runner injection molding tool according to claim 4, characterized in that: The upper and lower surfaces of the bearing plate (7) are fixedly connected with riser pads (9), and the upper riser pads (9) and the lower riser pads (9) are in contact with the upper mounting plate (1) and the upper template (3).

6. A small runner injection molding tool according to claim 5, characterized in that: The end of the extended nozzle (11) away from the support plate (7) is located inside the mounting groove (10). The discharge nozzle at the bottom of the extended nozzle (11) is connected to the gate (12). A contact sleeve (16) is installed inside the discharge nozzle. A compartment is formed between the contact sleeve (16) and the bottom end of the discharge nozzle. A resin gel layer (17) is formed inside the compartment.

7. A small runner injection molding tool according to claim 6, characterized in that: Heaters (18) are embedded inside the support plate (7) and on both sides of the second flow channel (15). A clearance is provided at one end of the support plate (7) between the two heaters (18), and a thermocouple sensor (19) is installed inside the clearance.

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