Small-tonnage double-color injection molding process and injection molding machine for producing large-projection-area products

Abstract

The invention belongs to the technical field of injection molds, and particularly relates to a small-tonnage double-color injection molding process and an injection molding machine for producing large-projection-area products, and the injection molding process comprises the following steps: S1, arranging a forming rear mold and a forming front mold, arranging a one-color nozzle and a two-color nozzle on the front mold, and respectively connecting the one-color nozzle and the two-color nozzle with a one-color hot nozzle and a two-color hot nozzle; s2, mold closing is conducted, specifically, a one-color nozzle is filled with a one-color forming material through a one-color hot nozzle, and pressure maintaining, cooling and mold opening are conducted; s3, rotating the rear mold by 180 degrees, then closing the mold, filling a one-color nozzle with a one-color forming material through a one-color hot nozzle, and maintaining the pressure; s4, after filling in the step S3 is completed, the two-color nozzle is filled with a two-color forming material through a two-color hot nozzle, and pressure maintaining, cooling and mold opening are conducted; s5, the product subjected to two-color forming in the step S4 is ejected out through an ejector pin plate, and the product is taken out; and S6, the step S3 is executed again, and the operation is repeated. According to the invention, efficient matching of a double-color large-projection-area product and a small-tonnage injection molding machine can be realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of injection molds, and particularly relates to a small-tonnage two-color injection molding process and an injection molding machine for producing products with a large projected area. Background Art

[0002] At the present stage of the rapid development of injection molds, there are more and more complex injection molded parts. Among them, two-color molds are increasingly widely used in the field of automotive lamp injection molded parts. Since calculating the injection pressure requires the primary molding pressure + the secondary molding pressure (injection pressure = product projected area X filling pressure per unit area of plastic material (taking PC as an example: 700 KG / cm2)), the added pressure will be very large, and a large-tonnage injection molding machine is required to match. This has created a problem of matching large projected area products with injection molding machines. Traditional injection molding processes have problems such as waste of injection molding machine resources and unstable product quality when producing products with a large projected area. For example, using a large two-color injection molding machine to produce products with a large projected area will result in high resource consumption and increased costs; while inappropriately reducing the injection molding machine size will cause the mold to be pushed open by the injection pressure due to insufficient clamping force, resulting in product flash at the parting line and affecting product quality. Summary of the Invention

[0003] The purpose of the present invention is to solve the defects and deficiencies in the prior art, and provide a small-tonnage two-color injection molding process and an injection molding machine for producing products with a large projected area, so as to achieve an efficient match between two-color large projected area products and small-tonnage injection molding machines.

[0004] To achieve the above purpose, the technical solution adopted by the present invention is: a small-tonnage two-color injection molding process for producing products with a large projected area, including the following steps:

[0005] S1. Set the post mold and the pre mold. An injection nozzle of the first color and an injection nozzle of the second color are provided on the pre mold. The injection nozzle of the first color and the injection nozzle of the second color are respectively connected to a hot nozzle of the first color and a hot nozzle of the second color. An injection cavity is formed between the post mold corresponding to the positions of the hot nozzle of the first color and the hot nozzle of the second color and the pre mold;

[0006] S2. Close the mold. The injection nozzle of the first color fills the molding material of the first color through the hot nozzle of the first color, hold the pressure, cool, and then open the mold;

[0007] S3. After the post mold rotates 180°, close the mold. The injection nozzle of the first color fills the molding material of the first color through the hot nozzle of the first color, and hold the pressure;

[0008] S4. After the filling in step S3 is completed, the injection nozzle of the second color fills the molding material of the second color through the hot nozzle of the second color, hold the pressure, cool, and then open the mold;

[0009] S5. Push out the product that has completed the second-color molding in step S4 through the ejector plate, and take out the part;

[0010] S6. Re-execute step S3 and repeat this process in a loop.

[0011] Preferably, the first-color nozzle and the second-color nozzle are filled separately. After the first-color nozzle finishes filling and holding pressure, the second-color nozzle starts to fill and hold pressure.

[0012] Preferably, the larger injection pressure between the first-color nozzle and the second-color nozzle determines the selection of the injection tonnage.

[0013] Preferably, the first-color molding material is a black sheet, and the second-color molding material is a transparent sheet.

[0014] Preferably, in step S3, the rear mold can rotate 180° driven by the machine table turntable, rotating the first-color molding material to the position corresponding to the second-color hot nozzle.

[0015] Preferably, in step S5, the product after second-color molding includes a black sheet and a transparent sheet covering the black sheet. The black sheet has through holes, and the through holes and the transparent sheet form a transparent window.

[0016] An injection molding machine for implementing the above small-tonnage two-color injection molding process for producing products with a large projection area includes a molded rear mold and a front mold. The front mold is provided with a first-color hot nozzle and a second-color hot nozzle. The first-color hot nozzle and the second-color hot nozzle are respectively connected to a first-color nozzle and a second-color nozzle. After the molded rear mold and the front mold are clamped, they are positioned with the machine table through a locating ring. A machine table turntable is arranged on the side of the molded rear mold away from the front mold. The molded rear mold can rotate under the action of the machine table turntable, and a thimble plate is arranged between the machine table turntable and the molded rear mold.

[0017] Preferably, there are two locating rings, which respectively correspond to the positions of the first-color nozzle and the second-color nozzle.

[0018] After adopting the above technical solution, a small-tonnage two-color injection molding process and an injection molding machine for producing products with a large projection area provided by the present invention have the following beneficial effects:

[0019] 1) The present invention can improve the utilization rate of the injection molding machine, avoid waste of resources, and can select an injection molding machine according to a single product, and a smaller machine table can be selected;

[0020] 2) The present invention solves the appearance defects of products with a large projection area caused by insufficient clamping force. During two-color injection molding, the clamping force does not need to be greater than the sum of the injection pressures of the two-color nozzles, and only needs to be greater than the larger injection pressure;

[0021] 3) The present invention reduces the selected tonnage of the injection molding machine accordingly, realizing an efficient matching between two-color products with a large projection area and a small-tonnage injection molding machine. Description of the Drawings

[0022] Figure 1 Schematic diagram of the structure of a small-tonnage two-color injection molding machine for producing products with a large projection area according to the present invention;

[0023] Figure 2 Schematic diagram of the structure of a product injection molded using the present invention;

[0024] Figure 3 is Figure 2 A-A side sectional view in

[0025] Figure 4 is Figure 2 B-B side sectional view in

[0026] Wherein: product 1, transparent window 2, first-color molding material 3, second-color molding material 4, first-color hot nozzle 5, second-color hot nozzle 6, first positioning ring 7, second positioning ring 8, front mold 9, rear mold 10, machine table 11, second-color injection nozzle 12, first-color injection nozzle 13, machine table turntable 14, ejector plate 15. Specific embodiments

[0027] The present invention will be further clearly and completely described below in conjunction with the accompanying drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way limits the present invention and its application or use. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0028] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0029] Unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that, for the sake of convenience in description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the said technologies, methods, and devices should be regarded as part of the authorization specification. In all the examples shown and discussed here, any specific values should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0030] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal", and "top, bottom" are generally based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description. Without contrary statements, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and thus should not be construed as limiting the protection scope of the present invention; the orientation words "inner, outer" refer to the inside and outside relative to the contour of each component itself.

[0031] For the convenience of description, spatial relative terms such as "above...", "over...", "on the upper surface of...", "above" can be used here to describe the spatial positional relationship of one device or feature to other devices or features as shown in the drawings. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation depicted in the drawings. For example, if the device in the drawing is inverted, the device described as "above other devices or structures" or "over other devices or structures" will then be positioned as "below other devices or structures" or "under other devices or structures". Thus, the exemplary term "above..." can include both the orientations of "above..." and "below...". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding interpretations should be made for the spatial relative descriptions used here.

[0032] In addition, it should be noted that the use of words such as "first", "second" to limit components is only for the convenience of differentiating the corresponding components. Without additional statements, the above words have no special meanings, and thus should not be construed as limiting the protection scope of the present invention.

[0033] As Figures 1-4As shown in the figure, a small-tonnage two-color injection molding process for producing products with a large projection area provided by the present invention includes the following steps:

[0034] S1. Set the post mold 10 and the pre mold 9 after molding. An injection nozzle 5 of the first color and an injection nozzle 6 of the second color are arranged on the pre mold 9. The injection nozzle 5 of the first color and the injection nozzle 6 of the second color are respectively connected to a hot nozzle 13 of the first color and a hot nozzle 12 of the second color. An injection cavity is formed between the post mold 10 corresponding to the positions of the hot nozzle 5 of the first color and the hot nozzle 6 of the second color and the pre mold 9.

[0035] S2. Close the mold. The injection nozzle 13 of the first color fills the molding material of the first color through the hot nozzle 5 of the first color, hold the pressure, cool, and then open the mold.

[0036] S3. After the post mold 10 rotates 180°, close the mold. The injection nozzle 13 of the first color fills the molding material of the first color through the hot nozzle 5 of the first color, and hold the pressure.

[0037] S4. After the filling in step S3 is completed, the injection nozzle 12 of the second color fills the molding material of the second color through the hot nozzle 6 of the second color, hold the pressure, cool, and then open the mold.

[0038] S5. Push out the product that has completed the second-color molding in step S4 through the ejector plate 15 and take the part.

[0039] S6. Re-execute step S3 and repeat the cycle in this way.

[0040] Among them, the injection nozzles 13 of the first color and 12 of the second color are filled separately. After the filling and pressure holding of the injection nozzle 13 of the first color are completed, the injection nozzle 12 of the second color fills and holds the pressure. Therefore, when selecting the tonnage of the injection molding machine, it is necessary to ensure that the injection pressure of the injection nozzle 12 of the second color (filling for secondary molding) < the clamping force of the injection molding machine, and the injection pressure of the injection nozzle 13 of the first color (filling for primary molding) < the clamping force of the injection molding machine, that is, the larger injection pressure of the injection nozzles 13 of the first color and 12 of the second color determines the selection of the injection tonnage. In step S3, the post mold 10 can rotate 180° driven by the turntable 14 of the machine tool, rotating the molding material of the first color from the non-operation side to the position corresponding to the hot nozzle 6 of the second color on the operation side. Further, the molding material 3 of the first color is a black sheet, and the molding material 4 of the second color is a transparent sheet, that is, the product that has completed the second-color molding includes a black sheet and a transparent sheet covering the black sheet. The black sheet has through holes, and the through holes and the transparent sheet form a transparent window 2.

[0041] The present invention also provides an injection molding machine for implementing the above-mentioned small-tonnage two-color injection molding process for producing products with a large projection area, including a formed rear mold 10 and a front mold 9. The front mold 9 is provided with a first-color hot nozzle 5 and a second-color hot nozzle 6. The first-color hot nozzle 5 and the second-color hot nozzle 6 are respectively connected to a first-color nozzle 13 and a second-color nozzle 12. After the formed rear mold 10 and the front mold 9 are closed, they are positioned with the machine table 11 through a locating ring. A machine table turntable 14 is arranged on the side of the formed rear mold 10 away from the front mold 9. The formed rear mold 10 can rotate under the action of the machine table turntable 14. A thimble plate 15 is arranged between the machine table turntable 14 and the formed rear mold 10.

[0042] Specifically, there are two locating rings, namely a first locating ring 7 and a second locating ring 8 respectively corresponding to the positions of the first-color nozzle 13 and the second-color nozzle 12.

[0043] During use, after the front mold 9 and the rear mold 10 are closed, they are positioned with the machine table 11 through the first locating ring 7 and the second locating ring 8, and the mold and the machine table pressing plate are fixed. The first-color nozzle 13 fills the first-molded material 3 black sheets through the first-color hot nozzle 5. When there are first-molded material 3 black sheets on the operation side of the rear mold 10, the second-color nozzle 12 fills the second-molded material 4 transparent sheets through the second-color hot nozzle 6. The completed product 1 is ejected by the thimble plate 15 on the operation side of the rear mold 10.

[0044] It should be noted that the first-color nozzle 13 and the second-color nozzle 12 do not fill simultaneously, but separately. First, the first-color nozzle 13 fills, and after the pressure holding is completed, then the second-color nozzle 12 fills and holds the pressure.

[0045] The small-tonnage two-color injection molding process and injection molding machine provided by the present invention for producing products with a large projection area can improve the utilization rate of the injection molding machine, avoid waste of resources, can select an injection molding machine according to a single product, and can select a smaller machine table, realizing an efficient matching of two-color large-projection-area products and small-tonnage injection molding machines.

[0046] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A small-tonnage two-color injection molding process for producing products with large projection areas, characterized in that: The following steps are involved: S1. Setting a molding rear mold and a front mold, wherein a single-color nozzle and a double-color nozzle are arranged on the front mold, wherein the single-color nozzle and the double-color nozzle are connected to a single-color hot nozzle and a double-color hot nozzle respectively, and an injection cavity is formed between the positions of the single-color hot nozzle and the double-color hot nozzle of the rear mold and the front mold; S2, mold closing, one-color nozzle fills one-color molding material through one-color hot nozzle, maintains pressure, cools, and opens the mold; S3, the rear mold rotates 180° and then closes the mold, and the single-color nozzle fills the single-color molding material through the single-color hot nozzle, and the pressure is maintained; S4, after the filling is completed in step S3, the two-color nozzle fills the two-color molding material through the two-color hot nozzle, maintains pressure, cools, and opens the mold; S5, ejecting the product formed by two-color molding in step S4 through the ejector plate and taking the product out; S6, re-execute step S3, and repeat this process over and over again.

2. A small-tonnage two-color injection molding process for producing products with a large projection area according to claim 1, characterized in that: The one-color nozzle and the two-color nozzle are filled separately, and the two-color nozzle is filled and pressure maintained after the one-color nozzle is filled and pressure maintained.

3. A small-tonnage two-color injection molding process for producing products with a large projection area according to claim 1, characterized in that: The larger injection pressure of the one-color nozzle and the two-color nozzle determines the selection of injection tonnage.

4. A small-tonnage two-color injection molding process for producing products with a large projection area according to claim 1, characterized in that: The one-color molding material is a black sheet, and the two-color molding material is a transparent sheet.

5. The small-tonnage two-color injection molding process for producing products with a large projection area according to claim 1, characterized in that: In step S3, the rear mold can be driven by the machine turntable to rotate 180 degrees to rotate the one-color molding material to the position corresponding to the two-color hot nozzle.

6. A small-tonnage two-color injection molding process for producing products with a large projection area according to claim 4, characterized in that: In step S5, the product after two-color molding includes a black sheet and a transparent sheet covering the black sheet, the black sheet has a through hole, and the through hole and the transparent sheet are combined to form a transparent window.

7. An injection molding machine for implementing the small-tonnage two-color injection molding process for producing products with a large projection area as described in any one of claims 1 to 6, characterized in that: It includes a rear molding mold and a front mold, the front mold is provided with a single-color hot nozzle and a two-color hot nozzle, the single-color hot nozzle and the two-color hot nozzle are respectively connected to a single-color nozzle and a two-color nozzle, the rear molding mold and the front mold are positioned with the machine through a positioning ring after being molded together, a machine turntable is arranged on the side of the rear molding mold away from the front mold, the rear molding mold can rotate under the action of the machine turntable, and an ejector plate is arranged between the machine turntable and the rear molding mold.

8. A small-tonnage two-color injection molding machine for producing products with a large projection area according to claim 7, characterized in that: There are two positioning rings, which correspond to the positions of the one-color nozzle and the two-color nozzle respectively.

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