A type of injection mold for continuous injection molding

Abstract

This utility model discloses a continuously injectable injection mold, relating to the field of mold manufacturing. The utility model includes a moving mold, a stationary mold, and a finished plastic product. A re-ejection device is provided at the bottom of the moving mold. The re-ejection device includes a cylinder, a piston rod, and a fixed plate. A connecting block is sleeved on the outer side of the piston rod, and an ejector pin is provided on the upper side of the connecting block. An air outlet is formed on the outer wall of the ejector pin, and an air inlet is formed on one side of the connecting block. The re-ejection device integrates the cylinder into the bottom of the moving mold through an embedded design. The rigid connection between the rigid fixed plate and the moving mold eliminates vibration displacement. The horizontal drive of the piston rod synchronously achieves deep cavity positioning of the ejector pin during the mold closing stage and ejection of the product during the mold opening stage. The top of the hollow ejector pin is sealed to block the backflow of melt air. High-pressure airflow is introduced through the air inlet and ejected through mirror-symmetrical air outlets, forming a uniform peeling airflow at the product interface, breaking through the limitations of traditional mechanical ejection force.

Description

Technical Field

[0001] This utility model relates to the field of mold manufacturing, specifically to an injection mold capable of continuous injection molding. Background Technology

[0002] Injection molds are core equipment in the production of plastic products. They inject molten plastic into a cavity under high pressure, which then cools and solidifies to form precision parts. Their core structure consists of a molding system, gating system, ejection mechanism, cooling water system, and guide / venting system, and they are widely used in consumer electronics, automotive, and medical plastic products industries.

[0003] In current injection molds, after the plastic product is shaped, it is ejected by the ejector pins. However, because the product is shaped by high-temperature heating, it has a certain degree of adhesion, which makes it difficult for the product to be removed in time, affecting work efficiency. Therefore, there is an urgent need to invent a tool that can help workers reduce the adhesion of plastic products and assist in demolding. Utility Model Content

[0004] Therefore, the purpose of this utility model is to provide an injection mold that can be continuously injected to solve the technical problem of plastic finished products sticking together.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a continuously injectable injection mold, comprising a moving mold, a stationary mold, and a finished plastic product. The bottom of the moving mold is provided with a re-ejection device, which includes a cylinder, a piston rod, and a fixed plate. A connecting block is sleeved on the outer side of the piston rod, and an ejector pin is provided on the upper side of the connecting block. An air outlet is provided on the outer wall of the ejector pin, and an air inlet is provided on one side of the connecting block.

[0006] By adopting the above technical solution, the direct drive between the cylinder and the piston rod replaces the traditional hydraulic mechanism, which can respond quickly at the moment of mold opening and eliminate the cycle waste caused by mechanical transmission delay.

[0007] Furthermore, the top-mounting device is embedded in the moving mold, and the moving mold provides support for the top-mounting device.

[0008] By adopting the above technical solution, the moving template body provides a fully enclosed rigid support for the cylinder and connecting block assembly, effectively suppressing resonance displacement and maintaining the linear accuracy of the piston rod's movement trajectory under the periodic impact of high-speed continuous injection molding.

[0009] Furthermore, the piston rod drives the connecting block to move horizontally, thereby limiting the displacement of the finished plastic product.

[0010] By adopting the above technical solution, before the melt is injected, the ejector pin is pre-extended into the deep cavity area of ​​the plastic product to act as an in-field core, thus solving the problem of axial bending caused by non-uniform cooling of the deep cavity part.

[0011] Furthermore, a plurality of ejector pins are provided, and the plurality of ejector pins are evenly distributed at the four corners of the connecting block.

[0012] By adopting the above technical solution, a spatially balanced vector ejection system is constructed by symmetrically distributing multiple ejector pins at the four corners. The ejector pin groups evenly distributed at the four corners of the connecting block avoid the risk of brittle fracture caused by local stress concentration.

[0013] Furthermore, the ejector pin has a hollow interior and a sealed top end to protect the top end of the ejector pin from backflow during the injection molding stage.

[0014] By adopting the above technical solution, when the high-pressure molten metal impacts the end face of the ejector pin, the sealing structure forms a physical barrier, completely preventing the plastic from penetrating into the inner cavity of the ejector pin.

[0015] Furthermore, one side of the air inlet is connected to the air outlet of an air compressor, which, in conjunction with the air outlet, allows the plastic product to be blown off.

[0016] By adopting the above technical solution, the direct connection between the air inlet and the air compressor and the directional spraying of the air outlet changes the traditional demolding mode. When the ejector pin pushes the plastic product away from the mold surface boundary point, the airflow is instantly sprayed out from the inclined air outlet.

[0017] Furthermore, the air outlet is provided in several groups, and the several groups of air outlets are designed in a mirror symmetrical manner with respect to the axis of the ejector pin.

[0018] By adopting the above technical solution, the mirror-symmetric design of several sets of air outlets relative to the pin axis generates tangential components of equal magnitude and opposite direction in the airflow ejected from the symmetrical air outlets, forming a rotating vortex peeling effect on the surface of the finished plastic product.

[0019] In summary, the present invention has the following main advantages:

[0020] 1. This utility model integrates the cylinder into the bottom of the moving mold through the embedded design of the re-ejection device. The rigid connection between the rigid fixing plate and the moving mold eliminates vibration displacement. The horizontal drive of the piston rod synchronously realizes the deep cavity positioning of the ejector pin during the mold closing stage and the ejection of the product during the mold opening stage. At the same time, the top of the hollow ejector pin is sealed to block the backflow of the melt air path. The air inlet introduces high-pressure airflow and sprays it out through the mirror-symmetrical air outlet, forming a uniform peeling airflow at the product interface, breaking through the limitations of traditional mechanical ejection force.

[0021] 2. This utility model uses ejector pins to precisely align with the strong areas of the product structure, preventing local overload breakage; combined with the timing coupling of mechanical ejection and air-assisted push, it eliminates demolding deformation of thin-walled parts, and the mirror-symmetrical air outlet generates self-balancing torque to offset the tangential component of the airflow, eliminating axial deflection of the product, thereby achieving enhanced positioning accuracy of deep cavity, zero ejection damage, and complete elimination of mold sticking failure. Attached Figure Description

[0022] Figure 1 This is a front view structural diagram of the present utility model;

[0023] Figure 2 This is a front view structural diagram of the top-mounting device of this utility model;

[0024] Figure 3 This is a three-dimensional structural diagram of the top-mounting device of this utility model;

[0025] Figure 4 This is a cross-sectional structural diagram of the top-mounting device of this utility model.

[0026] In the diagram: 1. Moving mold; 2. Ejection device; 201. Cylinder; 202. Piston rod; 203. Fixing plate; 204. Ejector pin; 205. Air outlet; 206. Air inlet; 207. Connecting block; 3. Plastic finished product; 4. Stationary mold. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0028] In this embodiment:

[0029] A type of injection mold capable of continuous injection molding, such as Figure 1-4 As shown, the mold includes a moving mold 1, a stationary mold 4, and a plastic finished product 3. The bottom of the moving mold 1 is equipped with a re-ejection device 2, which includes a cylinder 201, a piston rod 202, and a fixed plate 203. A connecting block 207 is sleeved on the outside of the piston rod 202, and an ejector pin 204 is provided on the upper side of the connecting block 207. An air outlet 205 is opened on the outer wall of the ejector pin 204, and an air inlet 206 is opened on one side of the connecting block 207. The direct drive between the cylinder 201 and the piston rod 202 replaces the traditional hydraulic mechanism, which can respond quickly at the moment of mold opening and eliminate the cycle waste caused by mechanical transmission delay. Through the sleeved design of the connecting block 207 and the ejector pin 204, the pneumatic thrust is accurately transmitted to the deep cavity area of ​​the mold. For the undercut or thin-walled characteristics of the plastic finished product 3, it provides stepless adjustment of the ejection force, which avoids surface indentation of the product and prevents demolding breakage. The airflow of the air outlet 205 on the side wall of the ejector pin 204 and the air inlet 206 at the bottom are coordinated.

[0030] See Figure 1 , Figure 2 , Figure 3 , Figure 4 The top-mounting device 2 and the moving mold 1 are embedded in each other. The moving mold 1 provides support for the top-mounting device 2, and the moving mold body provides full-enclosed rigid support for the cylinder 201 and the connecting block assembly. Under the periodic impact of high-speed continuous injection molding, it effectively suppresses resonance displacement, maintains the linear accuracy of the piston rod 202 movement trajectory, compresses the overall thickness of the mold, and directly increases the number of products molded in a single batch. The embedded assembly also completely isolates external dust from penetrating into the pneumatic components, eliminates cylinder seal failure caused by foreign objects, and significantly extends the service life of the device under high temperature and high pressure conditions.

[0031] See Figure 2 , Figure 3 , Figure 4 The piston rod 202 drives the connecting block 207 to move horizontally, which limits the displacement of the plastic product 3. Before the melt is injected, the ejector pin extends into the deep cavity area of ​​the plastic product 3 to act as the core in the mold, which solves the problem of axial bending caused by uneven cooling of the deep cavity part. When the mold is opened, it seamlessly switches to the ejection driving force, so that the ejector pin stroke and the mold parting surface movement form a dynamic coupling, eliminating the invalid time of the traditional ejection mechanism waiting for the mold to close, and realizing continuous production cycle compression.

[0032] See Figure 2 , Figure 3 , Figure 4 Several ejector pins 204 are provided, and the ejector pins 204 are evenly distributed at the four corners of the connecting block 207. The symmetrical distribution of multiple ejector pins 204 at the four corners constructs a spatially balanced vector ejection system. The ejector pin group evenly distributed at the four corners of the connecting block 207 avoids the risk of brittle fracture caused by local stress concentration. The multiple ejector pins work together to form a dynamic support grid, ensuring that the product is always in full contact with the ejector pin end face during the ejection stroke, eliminating the secondary manual shaping process in the traditional single ejector pin mode.

[0033] See Figure 2 , Figure 3 , Figure 4 The ejector pin 204 has a hollow interior and a sealed top. This design protects the top of the ejector pin 204 from backflow during the injection molding process. When the high-pressure molten metal impacts the ejector pin end face, the sealed structure forms a physical barrier, completely preventing plastic from seeping into the ejector pin cavity. It serves as a push rod to transmit mechanical thrust and as a high-speed transport pipeline for high-pressure airflow. The combination of the sealed end face and the side wall air outlet 205 ensures that the airflow is accurately released in the later stages of ejection, avoiding surface flow marks caused by premature airflow intervention during the initial cooling of the melt.

[0034] See Figure 1, Figure 2 , Figure 3 , Figure 4 One side of the air inlet 206 is connected to the air outlet of an air compressor. Through cooperation with the air outlet 205, the plastic product 3 is blown off. The air inlet 206 is directly connected to the air compressor and cooperates with the directional jet of the air outlet 205, which changes the traditional demolding mode. When the ejector pin 204 pushes the plastic product 3 away from the mold surface boundary point, the airflow is instantly sprayed out from the inclined air outlet. The high-pressure airflow applies auxiliary thrust along the demolding direction, which reduces the mechanical ejection force required for the product to leave the mold cavity. The composite demolding mode with air thrust as the main force and mechanical force as the auxiliary force solves the problem of sticking to the mold caused by vacuum adsorption force.

[0035] See Figure 1 , Figure 2 , Figure 3 , Figure 4 The air outlet 205 is provided in several groups. The air outlet 205 is designed in a mirror symmetry with respect to the axis of the ejector pin 204. The airflow from the symmetrical air outlets generates tangential components of equal magnitude and opposite direction, forming a rotating vortex peeling effect on the surface of the plastic finished product 3. This eliminates the off-center torsion caused by traditional single-sided air blowing. This dynamic balance demolding mechanism ensures that high-precision gear parts always maintain axial vertical displacement when they leave the mold, ensuring the dimensional stability of direct assembly.

[0036] The implementation principle of this embodiment is as follows: the moving mold 1 and the stationary mold 4 close to form a cavity, and molten plastic is injected to form a finished plastic product 3. The cylinder 201 of the ejector device 2 drives the piston rod 202 to extend, and pushes the ejector pin 204 horizontally into the deep cavity area of ​​the product through the connecting block 207. The top of the ejector pin 204 is sealed to prevent the melt from flowing back and also plays an auxiliary positioning role. The piston rod 202 remains extended, so that the ejector pin 204 continuously presses against the bottom surface of the deep cavity of the finished plastic product 3 to suppress shrinkage deformation. The fixing plate 203 provides rigid support for the cylinder 201 to ensure positioning stability. After the moving mold 1 and the stationary mold 4 separate... Cylinder 201 switches the air path direction, and piston rod 202 drives connecting block 207 to retract horizontally. Since ejector pin 204 is fixed on the upper side of connecting block 207, ejector pin 204 pushes the plastic product 3 out of the stationary mold cavity 4. At this time, multiple ejector pins 204 evenly distributed at the four corners apply force synchronously to prevent the product from tilting. When the ejector pin 204 finishes its ejection stroke, the external air source supplies air to the inner cavity of connecting block 207 through air inlet 206. The high-pressure airflow passes through the internal channel of hollow ejector pin 204 and sprays out at an inclined angle from the mirror-symmetrical air outlet 205 on the side wall, completely removing the residual adsorption force of the product and achieving damage-free removal.

[0037] Although embodiments of the present invention have been shown and described, these specific embodiments are merely explanations of the present invention and are not intended to limit the invention. The specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. After reading this specification, those skilled in the art may make modifications, substitutions, and variations to the embodiments as needed without departing from the principles and spirit of the present invention, provided that such modifications, substitutions, and variations are within the scope of the claims of the present invention and are protected by patent law.

Claims

1. A continuously injectable injection mold, characterized in that: The device includes a moving mold (1), a stationary mold (4), and a finished plastic product (3). The bottom of the moving mold (1) is provided with a back-ejection device (2). The back-ejection device (2) includes a cylinder (201), a piston rod (202), and a fixing plate (203). A connecting block (207) is sleeved on the outside of the piston rod (202). An ejector pin (204) is provided on the upper side of the connecting block (207). An air outlet (205) is opened on the outer wall of the ejector pin (204). An air inlet (206) is opened on one side of the connecting block (207).

2. The injection mold for continuous injection molding according to claim 1, characterized in that: The top-mounting device (2) is embedded in the moving mold (1), and the moving mold (1) provides support for the top-mounting device (2).

3. The injection mold for continuous injection molding according to claim 1, characterized in that: The piston rod (202) drives the connecting block (207) to move horizontally, thereby limiting the displacement of the plastic product (3).

4. The injection mold for continuous injection molding according to claim 1, characterized in that: A plurality of ejector pins (204) are provided, and the plurality of ejector pins (204) are evenly distributed at the four corners of the connecting block (207).

5. The injection mold for continuous injection molding according to claim 1, characterized in that: The ejector pin (204) has a hollow interior and a sealed top end to protect the top end of the ejector pin (204) from backflow during the injection molding stage.

6. The injection mold for continuous injection molding according to claim 1, characterized in that: The air inlet (206) is connected to the air outlet of an air compressor on one side, which, in conjunction with the air outlet (205), blows the plastic product (3) off.

7. The injection mold for continuous injection molding according to claim 1, characterized in that: The air outlet (205) is provided in several groups, and the several groups of air outlets (205) are designed in a mirror symmetry with respect to the axis of the ejector pin (204).

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