A two-color injection mold

Abstract

The application provides a double-color injection mold and belongs to the technical field of molds. The double-color injection mold solves the problem of how to improve the appearance quality of a double-color injection product. The double-color injection mold comprises a first fixed mold and a movable mold. The parting surface of the first fixed mold is a fixed mold parting surface one. The first fixed mold is provided with a glue sealing step which is protruded relative to the fixed mold parting surface one. The glue sealing step is located at the joint of the cavity of the first fixed mold and the fixed mold parting surface one. The upper surface of the glue sealing step is a glue sealing surface and the width of the glue sealing surface is smaller than the width of the fixed mold parting surface one. When the movable mold contacts the glue sealing step to close the mold, a gap is formed between the fixed mold parting surface one and the parting surface of the movable mold. When the closing force is increased to continue closing the mold, the movable mold can make the glue sealing step elastically deform and make the gap close. Through the above design, the imprinting area of the mold can be greatly reduced, so that the appearance defects of the molded product caused by imprinting can be greatly reduced, and finally the appearance quality of the product is greatly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of molds and relates to a double-color injection mold. Background Art

[0002] A two-shot mold is one in which two plastic materials are injected on the same injection molding machine, forming the product in two separate steps, but the product is ejected from the mold only once. This molding process, also known as double-shot molding, is typically completed with a single set of molds and requires a dedicated two-shot molding machine. Two-shot molding has been widely used in nearly every plastics industry, including daily necessities, decorative parts, automotive parts, electronics, power tools, medical products, home appliances, toys, and more. The production and molding of two-shot molds, as well as the research and development of two-shot and multi-shot molding machines and raw materials for two-shot molding, have also seen rapid development.

[0003] The two-shot mold structures currently used in the mold industry primarily include turntable, shaft, or improved versions. The turntable mechanism incorporates a 180° rotating turntable on the injection molding machine's movable platen, onto which the mold is mounted. Rotation of the turntable allows for mold repositioning and injection molding. The shaft mechanism incorporates a 180° rotating shaft on the injection molding machine's movable platen. This shaft is connected to the mold core and rotated via a proprietary transmission mechanism, pulling the mold back to close. This allows the mold core to rotate, enabling repositioning and injection molding. For example, Chinese patent application number 20162143927.2 discloses a manufacturing mold for a turntable-type two-color key, comprising a first fixed mold, a second fixed mold, and two movable molds with the same mold cavity. The first fixed mold has a first color mold cavity with an injection port, and the first mold cavity has a protrusion corresponding to the indicator and indicator hole of the two-color key. The second fixed mold has a second color mold cavity with an injection port and a protrusion corresponding to the indicator hole. The two movable molds are connected to a turntable, and the mold cavities of the two movable molds correspond to the first color mold cavity of the first fixed mold and the second color mold cavity of the second fixed mold, respectively. With this two-color injection mold, there is no need to separately injection mold the key body and the indicator of the two-color key and then bond them together, which simplifies the process and improves production efficiency.

[0004] However, similar to the above-mentioned traditional two-color injection molds, there are still the following defects: in the traditional two-color mold, the entire plane where the first fixed mold and the first movable mold are fitted is the parting surface and also the first sealing surface. Due to the existence of errors in mold component processing, mold matching, surface polishing, etc., when the above-mentioned first fixed mold and the first movable mold are closed, the first sealing surface is squeezed by the parting surface of the first movable mold, which will produce an imprint on the first sealing surface; and when the first color injection molding is completed, the first movable mold is moved by the driving mechanism to cooperate with the second fixed mold to form a second color mold cavity for second color injection molding. Due to the molding requirements of some products, the cavity and parting surface designed for the first fixed mold and the second fixed mold are different. In this case, the first sealing surface where the imprint is located will become part of the product molding surface, which will cause the molded product to have a rough surface due to the existence of the above-mentioned imprint, affecting the beauty of the product and ultimately affecting the appearance quality of the molded product.

[0005] To improve the appearance quality of molded products, those skilled in the art often consider improving the smoothness of the sealing surface and the corresponding movable mold parting surface, as well as increasing the machining and mold matching accuracy of related mold components, thereby reducing the occurrence of embossing and improving the appearance quality of the molded product. However, these commonly used technical methods place relatively high demands on mold manufacturing. Summary of the Invention

[0006] The purpose of the present invention is to address the above-mentioned problems in the existing technology and propose a two-color injection mold. The technical problem to be solved by the present invention is how to improve the appearance quality of the two-color injection molded product.

[0007] The objectives of the present invention can be achieved through the following technical solutions: A two-color injection mold, comprising a first fixed mold and a movable mold, the parting surface of the first fixed mold being the fixed mold parting surface one, characterized in that a sealing step is provided on the first fixed mold that is raised relative to the fixed mold parting surface one and has elasticity, the sealing step is located at the junction of the cavity of the first fixed mold and the fixed mold parting surface one, the upper surface of the sealing step is the sealing surface and the width of the sealing surface is smaller than the width of the fixed mold parting surface one; when the movable mold contacts the sealing step for mold closing, a gap is formed between the fixed mold parting surface one and the parting surface of the movable mold, and when the mold closing force is increased and the mold closing is continued, the movable mold can cause the sealing step to elastically deform and close the gap.

[0008] This is different from the existing two-color injection mold in which the entire parting surface on the first fixed mold is used for sealing, which results in a very wide embossing formed on the existing sealing surface, seriously affecting the appearance quality of the injection molded product. The present invention achieves the purpose of reducing the embossing and improving the appearance quality of the product by redesigning the sealing surface. Specifically, the present invention designs an outwardly protruding sealing step on the first fixed mold of the two-color mold, specifically at the intersection of the cavity of the first fixed mold and the fixed mold parting surface. The sealing step enables the parting surfaces of the first fixed mold and the movable mold to be separated to form a gap when the first fixed mold and the movable mold are closed. After such a design, when the first fixed mold and the movable mold are closed, the parting surfaces of the first fixed mold and the movable mold will not directly collide and contact, and the parting surface of the movable mold will first contact and squeeze with the sealing step, that is, the sealing step is buffered, and the embossing will be directly formed on the upper surface of the sealing step, that is, on the newly designed sealing surface, and will not be formed on the parting surface of the first fixed mold and the movable mold. At the same time, since the width of the sealing surface is smaller than the width of the fixed mold parting surface, the area of ​​​​the impression is reduced in disguise. In this way, when the movable mold moves to the second fixed mold under the two-color mold, the sealing surface is now part of the molding surface of the second color cavity. Since the impression has been greatly reduced, the appearance quality of the molded product can be improved; and since the sealing step has a certain elasticity, as the clamping force increases, the above-mentioned gap can be reduced and closed, and there will be no glue leakage due to the reduction of the sealing area, which ensures that the molded product will not produce batches, thereby further ensuring the appearance quality of the molded product.

[0009] In the aforementioned two-shot injection mold, the ratio of the width of the sealing surface to the width of the first fixed mold parting surface is 0.1 to 0.5. This width ratio design not only meets the product's sealing requirements but also minimizes the width of the sealing surface, thereby minimizing the area of ​​​​the embossing, thereby achieving the purpose of improving the appearance quality of the molded product.

[0010] In the aforementioned two-shot injection mold, the side of the sealing step facing away from the cavity of the first fixed mold is formed at an acute angle with the sealing surface. This design facilitates elastic deformation of the sealing step under compression, thereby preventing glue leakage from the sealing surface and maintaining the appearance quality of the molded product.

[0011] In the aforementioned two-shot injection mold, the side surface of the sealing step, located near the cavity of the first fixed mold, forms an obtuse angle with the sealing surface. This design facilitates elastic deformation of the sealing step under compression, thereby preventing glue leakage from the sealing surface and maintaining the appearance quality of the molded product.

[0012] In the above-mentioned two-shot injection mold, the height of the sealing step is 0.015mm to 0.055mm. This height is the gap size. By designing the above height, the gap is closed during mold closing to ensure sealing, ultimately ensuring the appearance quality of the molded product.

[0013] In the above-mentioned two-shot injection mold, the width of the sealing surface is 0.015 to 0.55 mm. Through the above design, while meeting the product sealing requirements, the width of the sealing surface is minimized, thereby minimizing the area of ​​​​the embossing, thereby achieving the purpose of improving the appearance quality of the molded product.

[0014] In the above-mentioned two-color injection mold, the sealing step is strip-shaped and arranged around the edge of the cavity of the first fixed mold. Through the above design, it is ensured that there will be no glue leakage problem.

[0015] In the above-mentioned two-color injection mold, the mold body of the first fixed mold has a clearance step, and the fixed mold parting surface 1 is the upper surface of the clearance step. Through the above design, it is beneficial to close the fixed mold parting surface 1 when the mold is closed.

[0016] Compared with the existing technology, this two-color injection mold has the following advantages: This two-color injection mold redesigns the width of the first fixed mold sealing surface by designing a sealing step, so that the imprinting area formed by the mold can be greatly reduced, thereby greatly reducing the appearance defects of the molded product caused by imprinting, and ultimately greatly improving the appearance quality of the molded product. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a partial schematic diagram of the overall framework of the two-color injection mold.

[0018] Figure 2 yes Figure 1 Partial schematic diagram of the cross-sectional structure at point A in the middle.

[0019] Figure 3 yes Figure 2 A partial enlarged schematic diagram of point B in the middle.

[0020] Figure 4 It is a structural schematic diagram of the first fixed mold in this two-color injection mold.

[0021] In the figure, 1, first fixed mold; 11, fixed mold parting surface 1; 12, air avoidance step; 2, second fixed mold; 3, movable mold; 4, sealing step; 41, sealing surface; 5, gap; a, first color molding cavity. DETAILED DESCRIPTION

[0022] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments.

[0023] Specifically, if Figure 1 As shown, the double-color injection mold includes a first fixed mold 1 and a second fixed mold 2 with different cavities, and also includes two movable molds 3 with the same cavity. Figure 2 As shown, when the cavity of the first fixed mold 1 and the cavity of the corresponding movable mold 3 are closed, a first color molding cavity a that is consistent with the shape requirements of the first color injection molded part can be formed. Figure 3 and Figure 4 As shown, the fixed mold parting surface 11 and the mold body of the first fixed mold 1 are provided with an air-avoiding step 12, and the parting surface of the first fixed mold 1 is the upper surface of the air-avoiding step 12. Among them, the first fixed mold 1 is provided with a sealing step 4 that is raised relative to the fixed mold parting surface 11 and has an elastic strip shape. The sealing step 4 is located at the junction of the mold cavity of the first fixed mold 1 and the fixed mold parting surface 11, and is arranged around the edge of the mold cavity of the first fixed mold 1. The upper surface of the sealing step 4 is a sealing surface 41, and the width of the sealing surface 41 is smaller than the width of the fixed mold parting surface 11. When the sealing step 4 contacts the movable mold 3 for mold closing, a gap 5 is formed between the fixed mold parting surface 11 and the parting surface of the movable mold 3. When the mold closing force is increased and the mold closing is continued, the movable mold 3 can squeeze the sealing step 4 to cause elastic deformation and close the gap 5.

[0024] Preferably, in this embodiment, the side of the sealing step 4 facing away from the cavity of the first fixed mold 1 forms an acute angle with the sealing surface 41. The side of the sealing step 4 facing closer to the cavity of the first fixed mold 1 forms an obtuse angle with the sealing surface 41. The width of the sealing surface 41 is 0.015 mm to 0.55 mm, and the ratio of the width of the sealing surface 41 to the width of the fixed mold parting surface 11 is 0.1 to 0.5. The raised height of the sealing step 4 is 0.015 mm to 0.055 mm.

[0025] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Persons skilled in the art may make various modifications, additions, or substitutions to the described specific embodiments without departing from the spirit of the present invention or exceeding the scope of the appended claims.

[0026] Although this document frequently uses terms such as first fixed mold 1, fixed mold parting surface 11, clearance step 12, second fixed mold 2, movable mold 3, sealing step 4, sealing surface 41, gap 5, and first color molding cavity a, the use of other terms is not excluded. These terms are used solely to more conveniently describe and explain the essence of the present invention; interpreting them as any additional limitations would be contrary to the spirit of the present invention.

Claims

1. A two-color injection mold, comprising a first fixed mold (1) and a second fixed mold (2) with different cavities, and two movable molds (3) with the same cavity, wherein the parting surface of the first fixed mold (1) is a fixed mold parting surface 1 (11), characterized in that: The first fixed mold (1) is integrally provided with a sealing step (4) which is raised relative to the fixed mold parting surface (11) and has elasticity. The sealing step (4) is located at the junction of the mold cavity of the first fixed mold (1) and the fixed mold parting surface (11). The upper surface of the sealing step (4) is a sealing surface (41) and the width of the sealing surface (41) is smaller than the width of the fixed mold parting surface (11). When the movable mold (3) contacts the sealing step (4) for mold closing, a gap (5) is formed between the fixed mold parting surface (11) and the parting surface of the movable mold (3). When the mold closing force is increased and the mold closing is continued, the movable mold (3) can cause the sealing step (4) to elastically deform and close the gap (5).

2. The double-color injection mold according to claim 1, characterized in that: The ratio of the width of the sealing surface (41) to the width of the fixed mold parting surface (11) is 0.1 to 0.

5.

3. The double-color injection mold according to claim 1 or 2, characterized in that: The inner angle between the side surface of the sealing step (4) away from the cavity of the first fixed mold (1) and the sealing surface (41) is an acute angle.

4. The double-color injection mold according to claim 1 or 2, characterized in that: The inner angle between the side surface of the sealing step (4) close to the cavity of the first fixed mold (1) and the sealing surface (41) is an obtuse angle.

5. The two-color injection mold according to claim 1 or 2, characterized in that: The raised height of the sealing step (4) is 0.015 mm to 0.055 mm.

6. The double-color injection mold according to claim 1 or 2, characterized in that: The width of the sealing surface (41) is 0.015 mm to 0.55 mm.

7. The two-color injection mold according to claim 1 or 2, characterized in that: The sealing step (4) is strip-shaped and arranged around the edge of the cavity of the first fixed mold (1).

8. The two-color injection mold according to claim 1 or 2, characterized in that: The mold body of the first fixed mold (1) is provided with a space-avoiding step (12), and the first fixed mold parting surface (11) is the upper surface of the space-avoiding step (12).

Images