A multi-layer stacked hot runner system for injection molds

Abstract

The application relates to a multilayer stacked hot runner system of an injection mold and belongs to the technical field of injection hot runner. The multilayer stacked hot runner system comprises a top plate, a flow distribution plate and an upper cavity plate, the bottom of the upper cavity plate is provided with an upper forming surface, the inside of the flow distribution plate is provided with a first runner plate, the bottom of the first runner plate is provided with a second runner plate connected therewith, the bottom of the second runner plate is provided with a plurality of third runner plates connected therewith, the third runner plates are provided with a plurality of feeding branches extending from the centers to the outsides, the bottom of the outer end of each feeding branch is provided with a hot nozzle connected therewith, and the bottom of the hot nozzle is connected with the upper forming surface. In the scheme, the second runner plate and the third runner plate can twice distribute the plastic melt, the pressure and the flow rate of the plastic melt in the two runner plates are uniformly distributed, the effect of balanced glue feeding is achieved, the plastic melt can uniformly and stably fill the whole cavity, and the precision requirement of the injection product is guaranteed.

Description

Technical Field

[0001] This invention belongs to the field of injection molding hot runner technology, and relates to a multi-layer stacked hot runner system for injection molds. Background Technology

[0002] With the continuous development of new energy vehicles, the battery pack in automobiles is a product with large size and strict precision requirements, as well as high safety requirements. Due to the large size and high precision requirements of the battery pack, and the presence of metal interlayer inserts to protect the internal cells, it is usually manufactured using stamping dies in current technology. However, the outer surface of stamped parts is not protected by plastic and is prone to rust. Therefore, it is necessary to use injection molds to inject a plastic shell onto the surface of the stamped parts, which serves to prevent rust and also provides better sound insulation.

[0003] However, the hot runner structure on the injection mold in the existing technology still has some shortcomings. Due to the large size and high precision requirements of the battery pack, multiple hot nozzle structures can be used to inject plastic into the cavity at the same time. However, the hot runner structure in the existing technology cannot balance and control the pressure and speed of the injection, so that the plastic melt cannot fill the entire cavity evenly and stably, and the precision of the product cannot meet the production requirements. Summary of the Invention

[0004] The purpose of this invention is to address the problems existing in the prior art by proposing a multi-layer stacked hot runner system for injection molds. The technical problem to be solved by this invention is to achieve balanced injection of glue into large-size cavities with multiple gates, balance the melt pressure and flow rate of each hot nozzle, and significantly improve the injection molding accuracy of battery pack shells.

[0005] The objective of this invention can be achieved through the following technical solution: A multi-layer stacked hot runner system for injection molds, comprising a top plate, a manifold plate, and an upper cavity plate arranged in sequence. The upper cavity plate has an upper molding surface at its bottom. The manifold plate has a first runner plate inside. The bottom of the first runner plate has a connected second runner plate. The second runner plate extends to the corner of the manifold plate. The bottom of the second runner plate has several connected third runner plates. The third runner plates are respectively located at the ends of the second runner plates. The third runner plates have several feed branches extending outward from the center. The bottom of the outer end of each feed branch has a connected hot nozzle. The bottom of the hot nozzle is connected to the upper molding surface.

[0006] In this design, the upper and lower molding surfaces cooperate to form a molding cavity for injection molding. The molten plastic can cool the battery pack casing inside the molding cavity. In the hot runner structure, the molten plastic material is first injected into the first runner plate, then flows into the second runner plate connected to the bottom. After being diverted by the second runner plate, the molten plastic flows to the ends of the second runner plate, spreading evenly towards the corners of the diverting plate, and then flows into the third runner plate from the bottom of the outer end of the second runner plate. The molten plastic then flows into the third runner plate inside the third runner plate. The second flow is split, with the material evenly diffused from the center of the third runner plate to the peripheral feed branches, and then entering the bottom hot nozzles. The material is then fed from the hot nozzles to the bottom of the molding surface. Through this method, due to the large area of ​​the upper cavity plate, the second and third runner plates can split the plastic melt twice, evenly distributing the pressure and flow rate of the plastic melt inside the two runner plates, achieving a balanced feeding effect. This allows the plastic melt to fill the entire molding cavity evenly and stably, ensuring the precision requirements of the injection molded product even when the product size is large.

[0007] In the multi-layer stacked hot runner system of the above-mentioned injection mold, a first inlet is provided at the center of the top plate, and a second inlet is provided on the side wall of the manifold. One end of the first runner extends to the center of the manifold and connects with the first inlet at the top, while the other end extends horizontally to the side wall of the manifold and connects with the second inlet. The first inlet is located at the center of the front of the top plate, and the second inlet is located on the side wall of the manifold, which can meet the dual requirements of vertical and horizontal injection molding machines on site. The first runner connects the first and second inlets, ensuring that regardless of which inlet is feeding, the material flows into the second runner at the bottom.

[0008] In the multi-layer stacked hot runner system of the above-mentioned injection mold, an adjusting plate is provided on the side wall of the manifold. The interior of the adjusting plate has a connecting channel that connects to the first runner plate. The second feed port is located on the side of the adjusting plate near the upper cavity plate, and the bottom of the second feed port is connected to the connecting channel. By using the adjusting plate to connect the second feed port and the first runner plate, the position of the second feed port on the adjusting plate can be adjusted so that the height of the second feed port can be moved 100 mm towards the upper cavity plate to meet the production needs of different injection molding machines.

[0009] In the multi-layer stacked hot runner system of the above-mentioned injection mold, the second runner plate is H-shaped, and the bottom end of the first runner plate extending to the center of the manifold is connected to the top center of the second runner plate. The structure of the second runner plate facilitates the distribution of the plastic melt to the corners of the manifold, making the distribution of the plastic melt more uniform.

[0010] In the multi-layer stacked hot runner system of the above-mentioned injection mold, the bottom outer wall of the hot runner has an inverted conical structure, and the bottom of the hot runner has a gate that connects to the upper molding surface. The gate is stepped, gradually narrowing from top to bottom. The gate structure of the hot runner head adopts a small-head TVA structure, and the head is shortened and reduced to minimize gate marks and improve product quality.

[0011] In the multi-layer stacked hot runner system of the above-mentioned injection mold, each of the outer ends of the feed branches is equipped with a fixed hydraulic cylinder. The bottom of each hydraulic cylinder is equipped with a retractable needle valve, which is slidably connected to the inside of the feed branch and the hot runner nozzle. The bottom of the needle valve can move downwards to block the inlet. Several fixed solenoid valves are provided on the side wall of the manifold, and each solenoid valve is connected to a hydraulic cylinder. The solenoid valves control the hydraulic cylinders, which in turn move the needle valves inside the hot runner nozzle. When the bottom of the needle valve approaches the inlet, it reduces the flow rate of the hot runner nozzle, allowing for balanced control of pressure and flow rate at each injection point, thus improving product precision.

[0012] In the multi-layer stacked hot runner system of the above-mentioned injection mold, a first heating section is provided on the top outer wall of the hot nozzle, a second heating section is provided on the middle outer wall of the hot nozzle, and a third heating section is provided on the bottom outer wall of the hot nozzle. The three-stage heating on the outer wall of the hot nozzle allows for separate control of the three heating sections to generate different temperatures, resulting in a better heating effect on the molten plastic inside the hot nozzle.

[0013] In the multi-layer stacked hot runner system of the above-mentioned injection mold, a connecting plate is fixedly connected between the manifold plate and the upper cavity plate. A slidingly connected ejector plate is located inside the connecting plate. A fixed cylinder is mounted on the ejector plate, and a retractable piston rod is located at the top of the cylinder. The top of the piston rod is fixedly connected to the top plate. The ejector plate is used to mount ejector pins. After the cylinder pushes out the piston rod, it can push the ejector plate downwards, thereby ejecting the ejector pins from inside the upper molding surface, pushing the product on the upper molding surface to be demolded and separated, and then the product is picked up by a robotic arm.

[0014] In the multi-layer stacked hot runner system of the above-mentioned injection mold, the side walls of the first, second, and third runner plates are all provided with surrounding mounting grooves, and coils are installed inside the mounting grooves. The mounting grooves are used to wind the coils; when the coils are energized, they heat the runner plates, maintaining the fluidity of the molten plastic inside the runner plates. The mounting grooves are also used to install the coils; when the coils are energized, they heat the runner plates, maintaining the fluidity of the molten plastic inside the runner plates.

[0015] In the multi-layer stacked hot runner system of the above-mentioned injection mold, a junction box is fixedly installed on the top of the manifold. The junction box has several wiring ports, each with a single-sided fastener, and there is a gap between the wiring ports. The junction box supplies power to the hot runner system, and the single-sided fasteners on the wiring ports can improve the stability of the wiring; therefore, it is necessary to increase the gap between the wiring ports.

[0016] Compared with the prior art, the present invention has the following advantages: In this solution, due to the large size of the upper cavity plate, the second and third runner plates can divide the plastic melt twice, and evenly distribute the pressure and flow rate of the plastic melt inside the two runner plates to achieve a balanced injection effect. This allows the plastic melt to fill the entire molding cavity evenly and stably, ensuring the precision requirements of the injection molded product even when the product size is large. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural schematic diagram of the present invention; Figure 2 This is a schematic diagram of the internal structure of the flow divider of the present invention; Figure 3 This is a schematic diagram of the left half-section structure of the present invention; Figure 4 yes Figure 3 A magnified schematic diagram of the local structure; Figure 5 A schematic diagram of the structure of this invention viewed from below.

[0018] In the diagram, 1 is the top plate; 1a is the first feed inlet; 2 is the flow divider plate; 2a is the second feed inlet; 2b is the adjusting plate; 2b1 is the connecting flow channel; 2c is the solenoid valve; 3 is the upper cavity plate; 3a is the upper molding surface; 4 is the connecting plate; 4a is the ejector plate; 4b is the cylinder; 4b1 is the piston rod; 5 is the junction box; 5a is the wiring port; 5b is the single-sided buckle; 6 is the first flow channel plate; 6a is the mounting groove; 6a1 is the coil; 7 is the second flow channel plate; 8 is the third flow channel plate; 8a is the feed branch; 8b is the oil cylinder; 8b1 is the needle valve; 9 is the hot nozzle; 9a is the first heating section; 9b is the second heating section; 9c is the third heating section; 9d is the glue inlet. Detailed Implementation

[0019] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings to further illustrate the technical solutions of the present invention. However, the present invention is not limited to these embodiments.

[0020] like Figure 1As shown, the multi-layer stacked hot runner system of the injection mold includes a top plate 1, a manifold 2 fixedly connected to the rear of the top plate 1, a connecting plate 4 fixedly connected to the rear of the manifold 2, and an upper cavity plate 3 fixedly connected to the rear of the connecting plate 4. A first feed port 1a is provided at the center of the top plate 1. An adjusting plate 2b is provided on the side wall of the manifold 2. A second feed port 2a is provided on the side of the adjusting plate 2b near the upper cavity plate 3. An ejector plate 4a is slidably connected inside the connecting plate 4. A cylinder 4b is fixedly connected to the ejector plate 4a. A retractable piston rod 4b1 is provided at the top of the cylinder 4b. The top of the piston rod 4b1 is fixedly connected to the top plate 1. A junction box 5 is fixedly connected to the top of the manifold 2. A plurality of wiring ports 5a are provided on the junction box 5. A single-sided buckle 5b is provided on each wiring port 5a. There is a gap between the wiring ports 5a.

[0021] like Figure 2 As shown, the flow divider 2 has a first flow channel plate 6 inside. One end of the first flow channel plate 6 extends to the center of the flow divider 2 and is connected to the first feed inlet 1a at the top. The bottom of the first flow channel plate 6 is provided with a connected second flow channel plate 7. The second flow channel plate 7 extends to the corner of the flow divider 2 and is "H" shaped. The bottom of the end of the first flow channel plate 6 extending to the center of the flow divider 2 is connected to the top center of the second flow channel plate 7. The bottom of the second flow channel plate 7 is provided with several connected third flow channel plates 8. The third flow channel plates 8 are respectively provided at the ends of the second flow channel plate 7. The third flow channel plate 8 is provided with several feed branches 8a extending outward from the center. The side wall of the flow divider 2 is provided with several fixed solenoid valves 2c. The side walls of the first flow channel plate 6, the second flow channel plate 7 and the third flow channel plate 8 are all provided with a surrounding mounting groove 6a. The mounting groove 6a is provided with a coil 6a1 inside.

[0022] like Figure 3 Combination Figure 4 As shown, the upper cavity plate 3 has an upper molding surface 3a at its bottom. The bottom of the outer end of each feeding branch 8a is provided with a hot nozzle 9 connected to it. The bottom of the hot nozzle 9 is connected to the upper molding surface 3a. The outer wall of the bottom of the hot nozzle 9 has an inverted cone structure. The bottom of the hot nozzle 9 is provided with a glue inlet 9d connected to the upper molding surface 3a. The glue inlet 9d is a stepped shape that gradually narrows from top to bottom. The top of the outer end of each feeding branch 8a is provided with a fixed oil cylinder 8b. The bottom of the oil cylinder 8b is provided with a retractable needle valve 8b1. The needle valve 8b1 is slidably connected to the inside of the feeding branch 8a and the hot nozzle 9. The bottom of the needle valve 8b1 can move down to block the glue inlet 9d. The solenoid valve 2c is connected to the oil cylinder 8b respectively. The top outer wall of the hot nozzle 9 is provided with a first heating section 9a. The middle outer wall of the hot nozzle 9 is provided with a second heating section 9b. The bottom outer wall of the hot nozzle 9 is provided with a third heating section 9c.

[0023] like Figure 5 As shown, the other end of the first flow channel plate 6 extends horizontally to the side wall of the flow divider plate 2 and is connected to the adjusting plate 2b. The interior of the adjusting plate 2b is provided with a connecting flow channel 2b1 connected to the first flow channel plate 6, and the bottom of the second feed port 2a is connected to the connecting flow channel 2b1.

[0024] The working principle of this solution is as follows: Figure 1-5 As shown, the upper molding surface 3a and the lower molding surface cooperate to form a molding cavity for injection molding. The plastic melt can cool the outer shell of the battery pack inside the molding cavity. In the hot runner structure, a three-layer stacked multi-stage diversion structure is adopted. The plastic raw material heated to the molten state can be injected into the first runner plate 6 through the first feed port 1a or the second feed port 2a, and then flow into the second runner plate 7 connected to the bottom of the first runner plate 6. After the diversion effect of the second runner plate 7, the plastic melt flows to the end of the second runner plate 7 and diffuses evenly towards the corner of the diversion plate 2. Then, it flows into the third runner plate 8 from the bottom of the outer end of the second runner plate 7. The plastic melt undergoes a second diversion inside the third runner plate 8. It is evenly diverted from the center of the third runner plate 8 to the feed branches 8a on the periphery, and finally enters the hot nozzle 9 at the bottom. The hot nozzle 9 feeds the plastic to the bottom of the upper molding surface 3a.

[0025] Because the upper cavity plate 3 has a large area, the second flow channel plate 7 and the third flow channel plate 8 can divide the plastic melt twice, and evenly distribute the pressure and flow rate of the plastic melt inside the two flow channel plates to achieve a balanced glue injection effect. Furthermore, the hydraulic cylinder 8b is controlled by the solenoid valve 2c, and the hydraulic cylinder 8b drives the needle valve 8b1 to move inside the hot nozzle 9. When the bottom of the needle valve 8b1 is close to the glue inlet 9d, it can reduce the flow rate of the glue injection from the hot nozzle 9, so that the pressure and flow rate of each glue injection point of the product can be balanced and controlled, ultimately improving the product precision.

[0026] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

[0027] Although this document frequently uses terms such as 1. top plate; 1a. first feed inlet; 2. flow divider plate; 2a. second feed inlet; 2b. adjusting plate; 2b1. connecting flow channel; 2c. solenoid valve; 3. upper cavity plate; 3a. upper molding surface; 4. connecting plate; 4a. ejector plate; 4b. cylinder; 4b1. piston rod; 5. junction box; 5a. wiring port; 5b. single-sided buckle; 6. first flow channel plate; 6a. mounting groove; 6a1. coil; 7. second flow channel plate; 8. third flow channel plate; 8a. feed branch; 8b. hydraulic cylinder; 8b1. needle valve; 9. hot nozzle; 9a. first heating section; 9b. second heating section; 9c. third heating section; 9d. glue inlet, etc., the possibility of using other terms is not excluded. The use of these terms is merely for the convenience of describing and explaining the essence of the invention; interpreting them as any additional limitation would contradict the spirit of the invention.

Claims

1. A multi-layer stacked hot runner system for an injection mold, comprising a top plate (1), a manifold (2), and an upper cavity plate (3) arranged sequentially, wherein the bottom of the upper cavity plate (3) is provided with an upper molding surface (3a), characterized in that, The flow divider (2) is provided with a first flow channel plate (6) inside. The bottom of the first flow channel plate (6) is provided with a second flow channel plate (7) connected to it. The second flow channel plate (7) extends to the corner of the flow divider (2). The bottom of the second flow channel plate (7) is provided with several connected third flow channel plates (8). The third flow channel plates (8) are respectively located at the ends of the second flow channel plate (7). The third flow channel plate (8) is provided with several feed branches (8a) extending outward from the center. The bottom of the outer end of each feed branch (8a) is provided with a connected hot nozzle (9). The bottom of the hot nozzle (9) is connected to the upper forming surface (3a).

2. The multi-layer stacked hot runner system for injection molds according to claim 1, characterized in that, The top plate (1) is provided with a first feed inlet (1a) at the center, and the side wall of the diversion plate (2) is provided with a second feed inlet (2a). One end of the first flow channel plate (6) extends to the center of the diversion plate (2) and is connected to the first feed inlet (1a) at the top. The other end of the first flow channel plate (6) extends horizontally to the side wall of the diversion plate (2) and is connected to the second feed inlet (2a).

3. The multi-layer stacked hot runner system for injection molds according to claim 2, characterized in that, The side wall of the flow divider (2) is provided with an adjustment plate (2b), and the interior of the adjustment plate (2b) is provided with a connecting flow channel (2b1) connected to the first flow channel plate (6). The second feed port (2a) is located on the side of the adjustment plate (2b) near the upper cavity plate (3), and the bottom of the second feed port (2a) is connected to the connecting flow channel (2b1).

4. The multi-layer stacked hot runner system for injection molds according to claim 2, characterized in that, The second flow channel plate (7) is "H" shaped, and the bottom of one end of the first flow channel plate (6) extending to the center of the flow divider plate (2) is connected to the top center of the second flow channel plate (7).

5. A multi-layer stacked hot runner system for injection molds according to claim 1, characterized in that, The bottom outer wall of the hot nozzle (9) has an inverted cone structure. The bottom of the hot nozzle (9) is provided with a glue inlet (9d) connected to the upper molding surface (3a). The glue inlet (9d) is a stepped shape that gradually narrows from top to bottom.

6. A multi-layer stacked hot runner system for injection molds according to claim 5, characterized in that, Each of the feed branches (8a) has a fixed oil cylinder (8b) at the top of its outer end. The bottom of the oil cylinder (8b) has a retractable needle valve (8b1). The needle valve (8b1) is slidably connected to the inside of the feed branch (8a) and the hot nozzle (9). The bottom of the needle valve (8b1) can move down to block the glue inlet (9d). The side wall of the diverter plate (2) has several fixed solenoid valves (2c). The solenoid valves (2c) are respectively connected to the oil cylinder (8b).

7. A multi-layer stacked hot runner system for injection molds according to claim 5, characterized in that, The hot nozzle (9) has a first heating section (9a) on its top outer wall, a second heating section (9b) on its middle outer wall, and a third heating section (9c) on its bottom outer wall.

8. A multi-layer stacked hot runner system for injection molds according to claim 1, characterized in that, A connecting plate (4) is fixedly connected between the flow divider (2) and the upper cavity plate (3). A slidingly connected ejector plate (4a) is provided inside the connecting plate (4). A cylinder (4b) is fixedly connected on the ejector plate (4a). A retractable piston rod (4b1) is provided at the top of the cylinder (4b). The top of the piston rod (4b1) is fixedly connected to the top plate (1).

9. A multi-layer stacked hot runner system for injection molds according to claim 1, characterized in that, The first flow channel plate (6), the second flow channel plate (7) and the third flow channel plate (8) are provided with a surrounding mounting groove (6a), and a coil (6a1) is provided inside the mounting groove (6a).

10. A multi-layer stacked hot runner system for an injection mold according to claim 9, characterized in that, The top of the diverter plate (2) is provided with a junction box (5) which is fixedly connected. The junction box (5) is provided with a number of connection ports (5a). The connection ports (5a) are provided with a single-sided buckle (5b). There is a gap between the connection ports (5a).

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