Building block, toy, mold and method for selecting an injection port for building block injection molding

Abstract

The application relates to the technical field of toy molding, and provides a building block, a toy, a mold and a selection method of a building block injection port, wherein the mold has a cavity for forming a product and a flow channel; the thickness of the cavity gradually decreases from a thick end to a thin end; the injection port of the flow channel is arranged at the thick end of the cavity; and an injection fluid mixed with functional particles is used for injection. For the building block part with gradually changed thickness, the injection port is arranged at the thick end of the cavity, so that the appearance trace is greatly inhibited, the product surface is improved in the aspect of appearance, and the interestingness is increased.

Description

Technical Field

[0001] This invention relates to the field of toy molding technology, specifically to a method for selecting injection gates for building blocks, toys, molds, and building block injection molding. Background Technology

[0002] As consumer demand for the appearance and texture of toys continues to rise, in order to give the surface of injection-molded products a special appearance effect such as metallic luster and frosted metallic texture, and to meet the diverse aesthetic needs of consumers, the industry generally adopts the technique of adding a certain proportion of metal powder to the injection molding raw materials. Through the uniform distribution of metal powder on the surface of injection-molded parts, toy products are given a visual texture and decorative quality that distinguishes them from ordinary injection-molded parts, which significantly enhances the market competitiveness of toys.

[0003] Currently, in the injection molding process of metal powder-added toys, metal powder is usually mixed with plastic substrate to form injection molding material. The molten injection fluid is then injected into the mold cavity using an injection molding machine, and after cooling and molding, a toy product with a special appearance is obtained. However, in actual injection molding production, due to the viscosity of the injection fluid itself, and the addition of metal powder altering its flow characteristics to some extent, flow marks and turbulence marks are left on the surface of the molded part as the injection fluid flows inside the mold cavity, forming obvious defects. There may be differences in wall thickness between the front and rear ends of the building blocks, especially for building blocks with a gradual thickness gradient. Often, the injection point is placed in the middle, and the injection fluid forms an encapsulating path as it fills outwards. The inconsistent arrival times of multiple injection fluid streams at the confluence point result in obvious bonding lines on the surface. Figure 2 As shown, the metal powder damages the uniform appearance and texture that the toy has, seriously affecting the surface aesthetics of the toy, reducing the product qualification rate, and increasing the rework costs and material losses for the manufacturing company.

[0004] Therefore, how to solve the problem of surface marks caused by metal powder additives in the injection molding process of toys, and improve the surface quality and pass rate of toy injection molded parts, has become an urgent technical problem to be solved in the current toy injection molding processing field. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a method for selecting injection gates for building blocks, toys, molds, and building block injection molding.

[0006] According to a method for selecting the injection gate for building block injection molding provided by the present invention, the mold has a cavity and a runner for molding a product, wherein the product is a sheet metal part; The cavity has a thick end and a thin end, with the thickness gradually decreasing from the thick end to the thin end. The injection port of the flow channel is positioned at the thick end of the cavity so that the flow direction of the injection fluid is from the thick end to the thin end, wherein: Injection molding is performed using injection fluid containing functional particles.

[0007] According to the present invention, a mold includes a cavity and a runner for molding a product, wherein the product is a sheet metal part, the cavity has a thick end and a thin end, the thickness of which gradually decreases from the thick end to the thin end, and the inlet of the runner is connected to the thick end of the cavity such that the flow tendency of the injection fluid is from the thick end to the thin end, wherein: Injection molding is performed using injection fluid containing functional particles.

[0008] Preferably, the thick end is located in the middle of the cavity, and the thin end is arranged circumferentially along the thick end.

[0009] Preferably, the thin ends are respectively disposed on both sides of the thick end.

[0010] Preferably, the mold is equipped with a hole-holding pin; The end of the orifice needle is flat.

[0011] Preferably, the inlet for the flow channel entering the cavity is a flat opening, the width of which is 0.6-1 mm and the thickness is 0.6-0.8 mm.

[0012] Preferably, the inlet for the flow channel entering the cavity is a round opening with an inner diameter of 0.6 to 0.8 mm.

[0013] Preferably, the functional particles are metal powders.

[0014] Preferably, the thickness of the cavity decreases uniformly from the center of the thick end to the center of the thin end.

[0015] Preferably, at least one part of the outer surface of the product protrudes outward to form a shape; The inner surface of the product corresponding to the shape is a concave structure.

[0016] Preferably, the outer surface of the product body has multiple shapes, and the shapes of the multiple shapes are different.

[0017] According to the present invention, a building block is molded using the method for selecting the injection gate of the building block or using the mold.

[0018] A toy according to the present invention includes the aforementioned building blocks.

[0019] Compared with the prior art, the present invention has the following beneficial effects: 1. For building block parts with a gradual change in thickness, this invention sets the injection port at the thicker end of the cavity. After the injection fluid enters the cavity, due to the different flow resistance at the thick and thin ends, the injection fluid flows and propels from the thickest to the thinnest. This allows the metal powder to maintain a stable migration trajectory in the injection fluid, improving the uniformity of functional particle distribution in the product. Throughout the filling process, the injection fluid velocity vector generally points towards the thinner end, reducing reverse or lateral flow splitting. The flow path is relatively simple, reducing the phenomena of injection fluid bifurcation, bypassing, and merging. This prevents metal powder from forming appearance defects such as flow marks, bright spots, and weld lines on the product surface due to inertial impact, local stagnation, or abnormal fountain flow turbulence. It greatly suppresses appearance defects, improves the aesthetics of the product surface, and increases its appeal.

[0020] 2. The present invention significantly reduces the flow around and backflow paths during the injection molding process, minimizing the flow resistance of the injection fluid and significantly reducing pressure loss. As a result, filling can be completed at a lower injection pressure, which can reduce injection pressure and energy consumption.

[0021] 3. As the present invention gradually advances from the thick end to the thin end of the building block, the flow cross-sectional area decreases, the injection fluid front speed can be adaptively adjusted, and the pressure gradient helps to push the injection fluid to the thinnest end, avoiding insufficient filling or underfilling defects at the thin end caused by the middle injection, which helps to improve the fullness of the thin end filling and enhance the appearance.

[0022] 4. The unidirectional filling of this invention makes the product cool and shrink more evenly, which can avoid the phenomenon of uneven curing speed caused by temperature differences in different areas due to changes in the flow state of the injection fluid. This can significantly reduce the risk of dimensional deformation such as warping and twisting. Attached Figure Description

[0023] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the structure when the inlet is connected to the end of the cavity with a larger thickness. Figure 2 This is a schematic diagram of the structure when the inlet is connected to the middle of the cavity in the prior art; Figure 3 This is a schematic diagram of the product structure in Example 6; Figure 4 This is a schematic diagram of the appearance structure of the product in Comparative Example 4.

[0024] The diagram shows: Flow channel 1; Inlet 11; Product 2; Style 21. Detailed Implementation

[0025] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0026] Example 1: To address the issue of visible marks appearing during injection molding of building block parts with varying thicknesses, this invention provides a method for selecting the injection port for building block injection molding. The injection molding process utilizes an injection fluid incorporating functional particles. The mold has a cavity and a runner 1. The cavity is used to mold the product 2. The functional particles are preferably metal powder. The cavity has varying thicknesses, with a thick end and a thin end, gradually decreasing in thickness from the thick end to the thin end. By positioning the injection port 11 of the runner 1 at the thick end of the cavity, the overall flow trend of the injection fluid is from the thick end to the thin end.

[0027] The present invention also provides a mold in which an injection fluid containing functional particles is used during injection molding. The mold includes a flow channel 1 and a cavity. The cavity is used to mold a product 2. The cavity has a thick end and a thin end. The thickness gradually decreases from the thick end to the thin end. The inlet 11 of the flow channel 1 is connected to the thick end of the cavity, so that the flow trend of the injection fluid is generally from the thick end to the thin end. For building block parts with varying thicknesses, this invention connects the injection port 11 to the thick end of the cavity. After the injection fluid enters the cavity, due to the different flow resistances at the thick and thin ends, the flow resistance is lower at thicker areas and higher at thinner areas. The injection fluid flows generally from the thick end to the thin end. Throughout the filling process, the injection fluid flows towards the thin end, reducing reverse or lateral flow splitting and preventing fluid branching and merging, thus improving the product's aesthetics. This differs from existing technologies that inject fluid from the middle thickness. In existing technologies, due to the lower resistance at the thick end and the higher resistance at the thin end, most of the injection fluid preferentially and quickly spreads towards the thick end before filling the thin end. This non-steady flow inevitably leads to the eventual merging of two or more flow fronts, resulting in weld lines. Simultaneously, local eddies or stagnation occur in the flow area, inducing powder aggregation and easily causing visible marks, reducing aesthetics.

[0028] It should be noted that product 2 in this invention is preferably a plate structure. The thickness of the cavity mentioned in this invention corresponds to the thickness of the plate, excluding some functional protrusions, bulges or structures extending to the outside of the plate on product 2. Functional protrusions can be understood as splicing structures for splicing, shapes set for aesthetic purposes, and protrusion structures set for other purposes.

[0029] Furthermore, the cavity corresponds to the structure of product 2. The definition of the thick and thin ends of the cavity can be understood according to the definition of thick and thin ends on product 2. The thickest area on product 2 is defined as the thick end of product 2, for example, the thick end is at the end of product 2. The thinnest area on product 2 is defined as the thin end. Figure 1 For example, product 2 is a centrally symmetrical or approximately centrally symmetrical geometric shape. The lower end of product 2 is the region with the thickest wall thickness, and the lower end of the product is the thick end. The connection between the glue inlet 11 defined in this invention and the thick end of the cavity can be understood according to the following rules: When the thick end and the thin end are located at the two ends of the product 2, the glue inlet 11 is preferably connected to the very end of the thick end, such as any position on the end face of the thick end. When the shape of product 2, the overall layout of the mold, or other reasons do not allow the gate 11 to be located at the very end of the thick end, the center point of the thick end and the center point of the thin end can be connected by a line, and product 2 can be divided into 4 equal parts along the direction of the line, such as... Figure 1 As shown, any position in the region closest to the thick end is considered the part connected to the inlet 11, such as... Figure 1 As shown, a location on the side, end face, or inside of the product 2 area below the dashed line R is selected as the location to connect with the glue inlet 11. It should be noted that when the center point of the thick end and the center point of the thin end are difficult to determine, the two points farthest apart on the thick and thin ends are used as the center points to form a line. The product 2 is divided into 4 equal parts along the direction of the line to determine the location to connect with the glue inlet 11.

[0030] Specifically, the inlet 11 of the flow channel 1 into the cavity is a round opening with an inner diameter of 0.6 to 0.8 mm, such as 0.7 mm or 0.8 mm. For example, if the inlet 11 is round and has a diameter of 0.8 mm, the product 2 after molding will have no marks on its surface and good aesthetics. By increasing the diameter of the inlet 11, this invention can reduce the resistance to melting, achieve stable filling, and improve the appearance.

[0031] The present invention also provides a building block, which is molded using a method for selecting the injection gate of the building block or using the mold of the present invention.

[0032] The present invention also provides a toy, characterized in that it includes building blocks.

[0033] Example 2: This embodiment is a preferred embodiment. In this embodiment, the thickness of the cavity decreases uniformly from the center of the thick end to the center of the thin end.

[0034] Example 3: This embodiment is a preferred embodiment. At least one part of the outer surface of product 2 protrudes outward to form shape 21. The inner surface of product 2 corresponding to shape 21 is a concave structure. The surface of the concave structure is similar to the surface of shape 21. In fact, it does not change the overall thickness of product 2. The overall thickness of product 2 is still a gradient structure. By setting shape 21, a special aesthetic effect on the surface of product 2 can be achieved.

[0035] In this embodiment, the outer surface of the product body has multiple shapes 21, and these shapes 21 are not identical. Although this embodiment provides shapes 21 in a localized area of ​​the product 2, it does not affect the overall thickness distribution of the product 2. By employing the method for selecting the injection gate in the building block molding process of this invention, marks can be avoided even for products with localized shapes 21, while ensuring a unique appearance. Figure 1 As shown, this enhances the fun.

[0036] Example 4: The difference between this embodiment and embodiment 1 is that the mold is equipped with a hole punch, the end of which is flat and extends into the cavity, so that a hole structure can be formed on product 2. In this embodiment, the end of the hole punch is flat, which can solve the problem of not being able to suppress the particle orientation marks on the surface of the injection molded product.

[0037] Product 2, molded using the method described in this embodiment, has no obvious marks on its surface and has an attractive appearance.

[0038] Example 5: The difference between this embodiment and embodiment 1 is that the inlet 11 of the flow channel 1 into the cavity is a flat opening with a width of 0.6 to 1 mm and a thickness of 0.6 to 0.8 mm.

[0039] The width of the sprue 11 of the runner 1 entering the cavity is 1 mm and the thickness is 0.8 mm, so that the appearance of the molded product 2 is free of marks.

[0040] Example 6: The difference between this embodiment and embodiment 1 is that when the thick end is located in the middle of the cavity, the thin end is arranged circumferentially along the thick end.

[0041] In this embodiment, the thin ends are respectively disposed on both sides of the thick end. That is to say, when the thick end of product 2 is located in the middle and the thin ends are located on both sides, the connection between the injection port 11 and the thick end of the cavity in this embodiment can be understood according to the following rules: The sum of the first quarter regions from the centerline of the thick end of product 2 to the corresponding ends of the two thin ends is taken as the location area connected to the gate 11. Specifically, preferably, the point on the centerline K of the middle part of product 2 is taken as the location connected to the gate 11; however, when the shape of product 2, the overall layout of the mold, or other reasons do not allow the gate 11 to be arranged at the point connecting the centerline K of the middle part of product 2, the connection point can be determined by dividing the line connecting the point on the centerline K of the thick end and the corresponding ends of the thin ends into four equal parts. Figure 3 As shown, a perpendicular line G is drawn from point J on the centerline K to line K. The intersection of line G and the thinnest end is point I. Point I is the point at the corresponding end of the thinnest end. Line segment JI is divided into four equal parts by dashed lines L, M, and N. The part between K and L on line G is the optional part connected to the glue inlet 11. The parts between K and L on all G lines from top to bottom on line K form the first 1 / 4 region from the centerline of the thick end to the corresponding end of the thinnest end on the right. Correspondingly, the parts between K and H on all G lines from top to bottom on line K corresponding to the corresponding end of the thinnest end on the left form the first 1 / 4 region from the centerline of the thick end to the corresponding end of the thinnest end on the left. Figure 3 For product 2, the point on the dotted line K is further away from the thin end of the corresponding position from top to bottom. Therefore, the area where the thick end is connected to the glue inlet 11 is a region that gradually widens from top to bottom.

[0042] like Figure 4 As shown, the injection point 11 is connected to the J point on the thick end for injection, and the appearance of the molded product 2 is free of marks.

[0043] Comparative Example 1: In Comparative Example 1, the mold is equipped with a screw rod. The end of the screw rod is designed to follow the shape of the outer surface of the product 2. That is, the end of the screw rod is the same shape as the part of the outer surface of the product directly opposite it. The end of the screw rod is a beveled surface or a curved surface. During the injection molding process, the shape of the end of the screw rod affects the appearance of the product 2.

[0044] Product 2, molded using this comparative method, has obvious surface marks. Compared to Example 4, its appearance is less attractive, reducing the product's appeal.

[0045] Comparative Example 2: In Comparative Example 2, the sprue 11 of the runner 1 into the cavity is a flat opening with a width of 0.5 mm and a thickness of 0.4 mm. The molded product 2 has obvious marks on its appearance.

[0046] Comparative Example 3: In Comparative Example 3, the inlet 11 of the flow channel 1 into the cavity is a round opening with an inner diameter of 0.4 mm.

[0047] Product 2, molded using this comparative method, has obvious surface marks. Compared to Example 1, its appearance is less attractive, reducing the product's appeal.

[0048] Comparative Example 4: In Comparative Example 4, the sprue 11 is connected to the thin end of the cavity. After molding, product 2 shows obvious surface marks, such as... Figure 4 As shown, compared to Example 6, the appearance is less attractive, which reduces the product's appeal.

[0049] by Figure 1 For example, the injection molding principle of this invention is as follows: During injection molding, an injection fluid containing metal particles is used. The thickness of the cavity gradually decreases from the thick end to the thin end. The inlet of the flow channel 1 is located at the thick end of the cavity, and the inlet 11 is set at the end with a larger cavity thickness. After the injection fluid enters the cavity, due to the different flow resistance at the thick end and the thin end, the injection fluid advances unidirectionally along the direction of the gradually thinning thickness, forming a stable flow. Throughout the filling process, the velocity vector of the injection fluid always points to the thin end, reducing reverse or lateral flow splitting. The flow path is single, avoiding injection fluid branching and merging, and improving the aesthetics of the product.

[0050] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0051] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A method for selecting the injection gate for building blocks, characterized in that, The mold has a cavity and a runner (1) for forming a product (2), said product (2) being a sheet metal piece; The cavity has a thick end and a thin end, with the thickness gradually decreasing from the thick end to the thin end. The inlet (11) of the flow channel (1) is positioned at the thick end of the cavity so that the flow tendency of the injection fluid is from the thick end to the thin end, wherein: Injection molding is performed using injection fluid containing functional particles.

2. A mold, characterized in that, Includes a cavity and a runner (1) for molding a product (2), the product (2) being a sheet metal part, the cavity having a thick end and a thin end, the thickness gradually decreasing from the thick end to the thin end, the inlet (11) of the runner (1) being connected to the thick end of the cavity such that the flow tendency of the injection fluid is from the thick end to the thin end, wherein: Injection molding is performed using injection fluid containing functional particles.

3. The method for selecting the injection gate for building blocks according to claim 1 or the mold according to claim 2, characterized in that, The thick end is located in the middle of the cavity, and the thin end is arranged circumferentially along the thick end. Preferably, the thin ends are respectively disposed on both sides of the thick end.

4. The method for selecting the injection gate for building blocks according to claim 1 or the mold according to claim 2, characterized in that, The mold is equipped with a hole-holding pin; The end of the orifice needle is flat.

5. The method for selecting the injection gate for building blocks according to claim 1 or the mold according to claim 2, characterized in that, The inlet (11) of the flow channel (1) into the cavity is a flat opening with a width of 0.6-1 mm and a thickness of 0.6-0.8 mm. The inlet (11) of the flow channel (1) into the cavity is a round opening with an inner diameter of 0.6-0.8 mm.

6. The method for selecting the injection gate for building blocks according to claim 1 or the mold according to claim 2, characterized in that, The functional particles are metal powders.

7. The method for selecting the injection gate for building blocks according to claim 1 or the mold according to claim 2, characterized in that, The thickness of the cavity decreases uniformly from the center of the thick end to the center of the thin end.

8. The method for selecting the injection gate for building blocks according to claim 1 or the mold according to claim 2, characterized in that, At least one part of the outer surface of the product (2) protrudes outward to form a shape (21); The inner surface of the product (2) corresponding to the shape (21) is a concave structure. Preferably, the outer surface of the product body has multiple shapes (21), and the shapes of the multiple shapes (21) are different.

9. A type of building block, characterized in that, The building blocks are molded using the method for selecting the injection gate as described in any one of claims 1, 3 to 8, or using the mold described in any one of claims 2 to 8.

10. A toy, characterized in that, Includes the building blocks as described in claim 9.

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