Anti-deformation injection mold for large thin-wall ABS (Acrylonitrile Butadiene Styrene) product

Abstract

The utility model belongs to the technical field of injection molds, and discloses an anti-deformation injection mold for a large thin-wall ABS (Acrylonitrile Butadiene Styrene) product, which comprises an upper mold and a lower mold, a cavity matched with an injection product is arranged between the upper mold and the lower mold, and a special-shaped waterway is fixedly arranged in the upper mold. A plurality of ejector pin bodies matched with a honeycomb structure of the bottom face of an injection product are arranged in the lower mold in a sliding mode, a fixing plate is fixedly arranged on the bottom face of each ejector pin body, and the outer side of each fixing plate is connected with an asynchronous gas jacking device through a pipeline. According to the scheme, the injection mold solves the problem of deformation of a large thin-wall ABS product during production, so that the quality of the product is improved, defective products are reduced, the melt flow uniformity is improved by more than 30%, the cooling efficiency is improved by 25%, the demolding stress is reduced by 40%, and the buckling deformation of a 600mm-grade thin-wall product can be controlled within 0.5%.

Description

Technical Field

[0001] This utility model belongs to the field of injection mold technology, specifically relating to an anti-deformation injection mold for large thin-walled ABS products. Background Technology

[0002] Injection molds are tools used to produce plastic products. They inject molten plastic into the mold cavity through the injection molding process, and after cooling, they form plastic products with a certain shape and size. They can mold plastic products with complex shapes, precise dimensions, or inserts in one go.

[0003] In the process of realizing this utility model, the inventors discovered that:

[0004] Products manufactured using injection molds (such as automotive writing boards) will inevitably deform to some extent after production. The larger the product size, the greater the deformation. At the same time, the thinner the product wall, the easier it is to deform. Deformation not only affects the aesthetics of the product's appearance, but in severe cases, it can even affect its subsequent use, ultimately causing a large number of products to be scrapped due to unusability, resulting in economic losses. Summary of the Invention

[0005] To address the problems mentioned in the background section, this invention provides an anti-deformation injection mold for large, thin-walled ABS products, which has the advantage of preventing deformation of these products. This invention solves the deformation problem that occurs during the production of large, thin-walled ABS products, thereby improving product quality, reducing defective products, achieving a melt flow uniformity improvement of over 30%, a cooling efficiency improvement of 25%, and a demolding stress reduction of 40%. It can control the warpage deformation of 600mm-class thin-walled products to within 0.5%.

[0006] Therefore, the technical solution of this utility model is as follows: a deformation-resistant injection mold for large thin-walled ABS products, comprising an upper mold and a lower mold mounted on a lower mold base, characterized in that: the mating surfaces of the upper mold and the lower mold are provided with cavities adapted to the injection molded product, and pre-deformation compensation parting surfaces are evenly distributed above and below the cavities; an irregularly shaped water channel is fixedly provided inside the upper mold; a plurality of ejector pin bodies adapted to the honeycomb structure of the bottom surface of the injection molded product are slidably arranged in the inner cavity of the lower mold base; the upper end of the ejector pin body passes through the lower mold and is flush with the pre-deformation compensation parting surface of the lower mold; the lower end of the ejector pin body is connected to a fixed plate; the fixed plate is slidably connected in the lower mold base through guide pins and limiting pins; a hydraulic cylinder is fixed on the outer side wall of the lower mold; and the two outer sides of the fixed plate are respectively fixedly connected to the piston rod of the hydraulic cylinder through fixed blocks.

[0007] Preferably, the inner cavity of the lower mold base is fixed with an injection molding system, which includes a balanced runner. The balanced runner adopts a spiral progressive runner structure with a spiral helix angle of 15°-25°. The outlet end of the balanced runner is provided with a thin film gate, which passes through the fixed plate and is flush with the lower wall of the cavity. An air intake valve control system is provided on the outer wall of the lower mold base. The balanced runner and the air intake valve control system are connected by a pipe. The air intake valve control system is equipped with a delay control module.

[0008] Preferably, the irregular water channel includes four sets of temperature control units arranged in a grid pattern, and the irregular water channel is 8-12mm away from the cavity surface of the upper mold.

[0009] Preferably, the lower mold 3 has multiple straight water passages fixedly arranged inside, and the straight water passages are 8-12mm away from the cavity surface of the lower mold.

[0010] Preferably, the ejector body includes an array of ejector pins corresponding to the honeycomb structure on the bottom surface of the injection molded product, and the diameter of the ejector pins is adapted to the size of the honeycomb structure on the bottom surface of the injection molded product.

[0011] Preferably, the curvature of the pre-deformation compensation parting surface is reverse-corrected by 0.1-0.3 mm based on the warpage of the product simulated by CAE. Vacuum exhaust grooves are provided on the parting surface, and the depth of the exhaust grooves is 0.015-0.02 mm. An external vacuum pump is connected to the end of the exhaust groove.

[0012] Preferably, a guide post is fixedly provided at the top of the lower mold, and a matching guide sleeve is provided inside the upper mold extending downwards, with the guide post slidably connected to the guide sleeve.

[0013] Beneficial effects: Compared with the prior art, this utility model solves the deformation problem of large thin-walled ABS products during production by coordinating the injection molding system with straight water channels, irregular water channels, ejector pin bodies, and pre-deformation compensation parting surfaces. This improves product quality, reduces the occurrence of defective products, and achieves a melt flow uniformity improvement of more than 30%, a cooling efficiency improvement of 25%, and a demolding stress reduction of 40%. It can control the warpage deformation of 600mm-class thin-walled products to within 0.5%. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0015] Figure 2 This is a schematic diagram of the lower mold of this utility model.

[0016] Figure 3 This is a schematic diagram of the internal installation of the lower mold of this utility model.

[0017] Figure 4This is an installation diagram of the injection molding system of this utility model.

[0018] Figure 5 This is a schematic diagram of the upper mold of this utility model.

[0019] Figure 6 This is a schematic diagram of the guide post and guide sleeve of this utility model.

[0020] Figure 7 This is an exploded view of the irregular water channel and upper mold of this utility model.

[0021] The following components are shown in the figure: 1. Upper mold; 2. Lower mold base; 3. Lower mold; 4. Ejector pin body; 5. Fixing plate; 6. Balanced runner; 7. Straight water channel; 8. Irregular water channel; 9. Guide pillar; 10. Hydraulic cylinder; 11. Asynchronous air ejector device; 12. Support leg. Detailed Implementation

[0022] The technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings, but this embodiment should not be construed as a limitation of this utility model.

[0023] This utility model is as follows Figures 1 to 7 As shown:

[0024] A deformation-resistant injection mold for large, thin-walled ABS products includes an upper mold 1 and a lower mold 3 mounted on a lower mold base 2. A cavity A, adapted to the injection molded product, is fitted onto the mating surfaces of the upper mold 1 and the lower mold. Pre-deformation compensation parting surfaces are evenly distributed above and below the cavity. An irregularly shaped water channel 8 is fixedly installed inside the upper mold 1. Several ejector pin bodies 4, adapted to the honeycomb structure of the bottom surface of the injection molded product, are slidably installed inside the lower mold base 2. The upper ends of the ejector pin bodies pass through the lower mold and are flush with the pre-deformation compensation parting surfaces of the lower mold. The lower ends of the ejector pin bodies 4 are connected to… The upper mold 1 is attached to the fixed plate 5, which is slidably connected in the lower mold base through guide posts and limit posts. A hydraulic cylinder is fixed on the outer wall of the lower mold. The two outer sides of the fixed plate 5 are respectively fixedly connected to the piston rod of the hydraulic cylinder through fixed blocks. The bottom of the fixed block is provided with a limit post, and the lower mold base is provided with a corresponding opening groove. Liquid glue is injected into the cavity between the upper mold 1 and the lower mold 3. After the liquid glue cools and solidifies, the upper mold 1 is first raised, and then the ejector body 4 is moved by the hydraulic cylinder. The ejector body 4 pushes the molded product inside the lower mold 3, thereby helping it to be demolded.

[0025] The lower mold base 2 has an injection molding system fixed inside its cavity. The injection molding system includes a balanced runner 6, which adopts a spiral progressive runner structure with a spiral helix angle of 15°-25°. The balanced runner is fixed to the bottom wall of the lower mold base cavity by a fixing ring. The fixing plate has corresponding through holes. The outlet end of the balanced runner has a thin film gate that passes through the fixing plate 5 and the lower mold 3 and is flush with the lower wall of the cavity. An air inlet valve control system is provided on the outer wall of the lower mold base. The balanced runner and the air inlet valve control system are connected by a pipe. The air inlet valve control system adopts an asynchronous air ejector device 11, which is located on the outer wall of the lower mold base. The asynchronous air ejector device is equipped with a delay control module with a delay time of 0.3-0.8s, which can control the injection volume and the fullness of the product. The balanced runner is used for the flow of liquid glue, while the asynchronous air ejector device can control the speed of liquid flow.

[0026] The irregular water channel includes four temperature control units arranged in a grid pattern, formed by 3D printing. The irregular water channel 8 is 8-12mm away from the cavity surface of the upper mold 1. It is designed according to the structure of the injection molded product and is used for cooling the upper mold.

[0027] The lower mold 3 has multiple straight water passages 7 fixedly installed inside, and the straight water passages 7 are 8-12mm away from the cavity surface of the lower mold 3, mainly for cooling the lower mold.

[0028] The ejector body 4 contains an array of ejector pins with a diameter of φ3-4mm. The ejector pin diameter is adapted to the size of the honeycomb structure on the bottom surface of the injection molded product to avoid interference. The ejector pin density is 1.5 times that of conventional designs. This structure can help the product to be demolded better and also reduce the deformation caused by pulling during demolding.

[0029] Among them, the curvature of the pre-deformation compensation parting surface is corrected by 0.1-0.3mm in the reverse direction according to the warpage of the product simulated by CAE. Vacuum exhaust grooves are provided on the parting surface, and the depth of the exhaust grooves is 0.015-0.02mm. An external vacuum pump is connected to the end of the exhaust groove. This structure can reduce the deformation and porosity of the product after production.

[0030] The lower mold 3 is fixedly provided with a guide post 9 at its top, and the upper mold is provided with a matching guide sleeve extending downward inside. The guide post is slidably connected to the guide sleeve to ensure the accuracy of the position of the upper mold and the lower mold.

[0031] The mold is also equipped with a support leg 12 on one side to prevent damage to the hydraulic cylinder when it is placed on its side.

[0032] Among them, the balanced flow channel 6 and the asynchronous air top device 11 are existing products and will not be described in detail; at the same time, this utility model also includes a power supply, controller and switch, etc., which are not the main technical points of this patent and will not be described in detail; the "front, back, left and right" perspectives of this device are as follows: Figure 1 The direction shown in the diagram is the reference.

[0033] The working principle of this utility model:

[0034] When using a large, thin-walled ABS product (automotive writing board) anti-deformation injection mold, firstly, the mold is installed on a 1000T injection molding machine. Liquid adhesive enters the internal cavities of the upper mold 1 and lower mold 3 through the balanced flow channel of the injection system 6. The air valve control system of the injection system is used to control the flow rate and on / off of the liquid adhesive. When the cavities of the upper mold 1 and lower mold 3 are completely covered with liquid adhesive, the injection is stopped. The upper mold 1 is cooled through the irregular water channel 8 inside the upper mold 1, and the lower mold 3 is cooled through the straight water channel 7 inside the lower mold 3. At this time, the injection molded product 2 is formed, and then it is ejected by the ejector pin body 4 on the top surface of the fixed plate 5, thus completing the production of the injection molded product 2. The upper mold and lower mold are slidably connected by guide pillars 9 and guide sleeves. This invention solves the deformation problem that occurs during the production of large thin-walled ABS products, thereby improving product quality, reducing the occurrence of defective products, improving melt flow uniformity by more than 30%, improving cooling efficiency by 25%, and reducing demolding stress by 40%. It can control the warpage deformation of 600mm-class thin-walled products to within 0.5%.

[0035] Any aspects not described in detail in this specification are techniques well-known in the art.

[0036] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A deformation-resistant injection mold for large thin-walled ABS products, comprising an upper mold (1) and a lower mold (3) mounted on a lower mold base (2), characterized in that: The upper mold (1) and the lower mold are fitted with cavities (A) adapted to the injection molded product. Pre-deformation compensation parting surfaces are evenly distributed on the upper and lower surfaces of the cavity. The upper mold (1) is fixedly provided with irregular water channels (8). The lower mold base (2) is slidably provided with several ejector bodies (4) adapted to the honeycomb structure of the bottom surface of the injection molded product. The upper end of the ejector body passes through the lower mold and is flush with the pre-deformation compensation parting surface of the lower mold. The lower end of the ejector body (4) is connected to the fixed plate (5). The fixed plate is slidably connected in the lower mold base through guide posts and limit posts. The outer side wall of the lower mold is fixed with a hydraulic cylinder. The two outer sides of the fixed plate (5) are fixedly connected to the piston rod of the hydraulic cylinder through fixed blocks.

2. The anti-deformation injection mold for large thin-walled ABS products according to claim 1, characterized in that: The lower mold base (2) has an injection system fixed in its inner cavity. The injection system includes a balanced runner (6). The balanced runner adopts a spiral progressive runner structure with a spiral rise angle of 15°-25°. The outlet end of the balanced runner is provided with a thin film gate, which passes through the fixed plate (5) and the lower mold (3) and is flush with the lower wall of the cavity. An air intake valve control system is provided on the outer wall of the lower mold base. The balanced runner and the air intake valve control system are connected by a pipe. A delay control module is provided in the air intake valve control system.

3. The anti-deformation injection mold for large thin-walled ABS products according to claim 1 or 2, characterized in that: The irregular water channel includes four sets of temperature control units arranged in a grid pattern. The irregular water channel (8) is 8-12mm away from the cavity surface of the upper mold (1).

4. The anti-deformation injection mold for large thin-walled ABS products according to claim 3, characterized in that: The lower mold (3) is fixedly provided with multiple straight water passages (7), and the straight water passages (7) are 8-12mm away from the cavity surface of the lower mold (3).

5. A deformation-resistant injection mold for large thin-walled ABS products according to claim 1, 2, or 4, characterized in that: The ejector body (4) includes an array of ejector pins corresponding to the honeycomb structure on the bottom surface of the injection molded product, and the diameter of the ejector pins is adapted to the size of the honeycomb structure on the bottom surface of the injection molded product.

6. The anti-deformation injection mold for large thin-walled ABS products according to claim 5, characterized in that: The curvature of the pre-deformation compensation parting surface is corrected in reverse by 0.1-0.3 mm based on the warpage of the product simulated by CAE. Vacuum exhaust grooves are provided on the parting surface, and the depth of the exhaust grooves is 0.015-0.02 mm. An external vacuum pump is connected to the end of the exhaust groove.

7. The anti-deformation injection mold for large thin-walled ABS products according to claim 6, characterized in that: The lower mold (3) is fixedly provided with a guide post (9) at the top, and the upper mold is provided with a guide sleeve extending downward inside, and the guide post is slidably connected to the guide sleeve.

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