Structure for improving burrs caused by shrinkage of double-color injection molding product

Abstract

The utility model discloses a structure for improving burrs caused by shrinkage of a double-shot product, which comprises a first-shot product, a second-shot product and a pitched roof structure, the second-shot product is wrapped at the outer end of the first-shot product, the second-shot product is wrapped in partial area of the lower end face of the first-shot product, and the pitched roof structure is arranged on the lower end face of the first-shot product. The inner side face of the first injection product is provided with a pitched roof structure for preventing the first injection product from shrinking, and the acting point of the pitched roof structure and the first injection product is located above the connecting position of the first injection product and the second injection product, namely the position where burrs are prone to being generated. According to the mode, under the condition that the appearance of a product is not changed and the assembly of the product is not influenced, the tendency of plastic shrinkage of the product is blocked through the additionally arranged inclined top structure at the blind hole, the risk of burrs caused by molding secondary injection is avoided, and post-treatment is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of injection molding, in particular to a structure for improving burrs caused by shrinkage of double-color injection molding products. Background Art

[0002] Two-color injection molding products, such as Figure 1 As shown, it is common to see burrs at the junction of one and two shots. Figure 2 The state of local burrs on the product. Burrs are caused by cooling shrinkage. The first shot product is deeper and is prone to shrinkage after molding. There is a gap between the first shot product and the mold, which leads to burrs during the second shot molding. The burrs stick to the first shot glue position and are easy to scratch the product. Figure 3 This is a schematic diagram of a two-shot product in a mold. The direction of the arrow is the direction of plastic shrinkage, which affects product quality. This burr needs to be removed manually, which can easily damage the product. The burr residue is difficult to control and the defective rate is high.

[0003] Based on the above defects and shortcomings, it is necessary to improve the existing technology and design a structure to improve the burrs caused by shrinkage of two-color injection molding products. Utility Model Content

[0004] The main technical problem solved by the utility model is to provide a structure for improving the burrs caused by shrinkage of two-shot injection molded products. The tendency of plastic shrinkage of the product is blocked by the added inclined top structure at the blind hole, the risk of burrs in the second shot molding is avoided, and post-processing is eliminated.

[0005] In order to solve the above technical problems, a technical solution adopted by the utility model is: to provide a structure for improving the burrs caused by shrinkage of two-shot injection molded products, the structure for improving the burrs caused by shrinkage of two-shot injection molded products includes a one-shot product, a two-shot product and a slanted top structure, the outer end of the one-shot product is wrapped with the two-shot product, a part of the lower end surface of the one-shot product is wrapped with the two-shot product, the inner side surface of the one-shot product is provided with a slanted top structure to prevent the one-shot product from shrinking, and the point of action of the slanted top structure and the one-shot product is located above the connection position between the one-shot product and the two-shot product, that is, the position where burrs are easily generated.

[0006] Preferably, a blind hole is provided in an area of ​​the inner side surface of the first-shot product close to the second-shot product, and a protrusion cooperating with the blind hole is provided on a side of the inclined roof structure close to the outer side surface of the first-shot product.

[0007] Preferably, the inclined top structure adopts an inclined top demolding, and the inner and outer sides of the inclined top demolding are provided with guiding inclined surfaces. The inclined top demolding is horizontally slidably installed on the injection molding upper mold, and a mold core that cooperates with the guiding inclined surface of the inclined top demolding is installed on the injection molding lower mold. The injection molding machine pushes upward to drive the injection molding lower mold to move upward. Under the guiding action of the guiding inclined surface, the mold core moves upward to drive the inclined top demolding to slide toward one side of the first shot product until the protrusion is inserted into the blind hole.

[0008] Preferably, the outer side surface of the inclined ejector mold is also provided with a contoured supporting arc surface for supporting the inner side surface of a shot product.

[0009] Preferably, the blind hole is square in shape.

[0010] Compared with the prior art, the beneficial effects of the utility model are:

[0011] After the first shot molding, the first shot product is fixed on the mold, and the inclined top of the inclined top structure at the square hole supports the first shot product to prevent the plastic from shrinking upward and avoid a gap between the first shot product and the mold;

[0012] Add blind holes near the burrs of the product to block plastic shrinkage, avoid burrs in the second shot, and eliminate post-processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram of the structure of a two-color injection molding product.

[0014] Figure 2 Schematic diagram of burrs caused by shrinkage of two-color injection molded products.

[0015] Figure 3 This is a schematic diagram of a two-shot product in a mold.

[0016] Figure 4 Schematic diagram of the structure to improve the burrs caused by shrinkage of two-color injection molded products.

[0017] Figure 5 Schematic diagram of a one-shot product structure to improve the burrs caused by shrinkage in two-shot molded products.

[0018] Figure 6 Schematic diagram of a two-shot product structure to improve the burrs caused by shrinkage of two-shot molded products.

[0019] Figure 7 A cross-sectional view of the structure in use to improve the burrs caused by shrinkage in two-color injection molded products.

[0020] Figure 8 Schematic diagram of the partial structure of the use status of the structure to improve the burrs caused by shrinkage of two-color injection molded products.

[0021] Fig. 9This is a schematic diagram of the burr indication position of the modified product of the utility model.

[0022] Among them, 1. one-shot product, 00. blind hole, 2. two-shot product, 3. inclined top structure, 30. bump, 31. guide slope, 32. contoured support arc surface, 4. pin, 5. injection molding upper mold, 51. ejector plate, 50. slide groove, 6. injection molding lower mold, 61. mold core. DETAILED DESCRIPTION

[0023] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0024] See also Figures 4 to 9 , the utility model embodiment includes:

[0025] A structure for improving burrs caused by shrinkage of a two-shot injection molded product, the structure for improving burrs caused by shrinkage of a two-shot injection molded product comprising a one-shot product 1, a two-shot product 2 and a sloping top structure 3, the outer end of the one-shot product 1 is wrapped with the two-shot product 2, a part of the lower end surface of the one-shot product 1 is wrapped with the two-shot product 2, the inner side surface of the one-shot product 1 is provided with a sloping top structure 3 for preventing the one-shot product 1 from shrinking, the sloping top structure 3 is demolded by a sloping top, a blind hole 00 is provided in an area of ​​the inner side surface of the one-shot product 1 close to the two-shot product 2, the blind hole 00 is close to the connection position of the one-shot product and the two-shot product, which is also a position where burrs are easily generated, the blind hole 00 is square, and the outer side surface of the sloping top demolding is provided with a protrusion 30 that can be inserted into the blind hole 00, the protrusion 30 is used to support the one-shot product 1 and block the shrinkage of the plastic.

[0026] The lower end of the inclined ejector is hung on the ejector plate 51 of the injection molding upper mold 5 through the pin 4. The ejector plate 51 is horizontally provided with a slide groove 50 for placing the pin 4. The inner and outer sides of the inclined ejector structure 3 are provided with guide slopes 31. The injection molding lower mold 6 is provided with a mold core 61 that cooperates with the guide slope 31 of the inclined ejector. The injection molding machine pushes upward to drive the plastic molding lower mold 6 to move upward. Under the guidance of the guide slope 31, the mold core 61 moves upward to drive the inclined ejector to slide toward one side of the first-shot product 1 until the protrusion 30 is inserted into the blind hole 00 to block the shrinkage of the plastic.

[0027] The outer side surface of the inclined ejection mold is also provided with a contoured supporting arc surface 32 for supporting the inner side surface of the first-shot product 1.

[0028] The utility model is a structure for improving the burrs caused by shrinkage of two-shot injection molded products. When the structure is working, after one shot molding, the one-shot product 1 is fixed on the upper mold, and the inclined ejector at the blind hole 00 supports the upward shrinkage trend of the one-shot product to avoid a gap between the one-shot product and the mold. The one-shot product 1 is rotated on the machine table to the second shot molding position to perform second shot injection molding. After the product is molded, the product is ejected by the ejector pin and the inclined ejector.

[0029] The utility model discloses a structure for improving burrs caused by shrinkage of two-shot injection molded products. Without changing the appearance of the product or affecting the assembly of the product, the utility model blocks the shrinkage tendency of the product plastic by adding an inclined top structure at the blind hole, thereby avoiding the risk of burrs in the second shot molding and eliminating post-processing.

[0030] The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A structure for improving the burrs caused by shrinkage of two-color injection molded products, characterized in that: The invention comprises a one-shot product (1), a two-shot product (2) and a sloping roof structure (3), wherein the outer end of the one-shot product (1) is wrapped with the two-shot product (2), a part of the lower end surface of the one-shot product (1) is wrapped with the two-shot product (2), and the inner side surface of the one-shot product (1) is provided with a sloping roof structure (3) for preventing the one-shot product (1) from shrinking, and the action point of the sloping roof structure (3) and the one-shot product (1) is located above the connection position between the one-shot product (1) and the two-shot product (2).

2. The structure for improving burrs caused by shrinkage of two-color injection molded products according to claim 1, characterized in that: A blind hole (00) is provided in an area of ​​the inner side surface of the first-shot product (1) close to the second-shot product (2), and a convex block (30) cooperating with the blind hole (00) is provided on a side of the inclined roof structure (3) close to the outer side surface of the first-shot product (1).

3. The structure for improving burrs caused by shrinkage of two-color injection molded products according to claim 2, characterized in that: The inclined ejection structure (3) adopts an inclined ejection mold, and the inner and outer side surfaces of the inclined ejection mold are provided with guiding inclined surfaces (31). The inclined ejection mold is horizontally slidably mounted on the injection molding upper mold (5), and the injection molding lower mold (6) is provided with a mold core (61) that cooperates with the guiding inclined surfaces (31) of the inclined ejection mold.

4. The structure for improving burrs caused by shrinkage of two-color injection molded products according to claim 3, characterized in that: The outer side surface of the inclined ejection mold is also provided with a contoured support arc surface (32) for supporting the inner side surface of a shot product (1).

5. The structure for improving burrs caused by shrinkage of two-color injection molded products according to claim 2, characterized in that: The blind hole (00) is square in shape.

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