Injection mold without stress marks on surface of product

Abstract

The utility model relates to the technical field of injection molds, in particular to an injection mold without stress marks on the surface of a product, which comprises a bottom plate and a top plate, a lower mold plate is fixedly mounted on the bottom plate through mold corners, a lower mold core is arranged in the lower mold plate, an upper mold plate is fixedly mounted on the top plate, an upper mold core is arranged in the upper mold plate, and a lower mold core is arranged in the upper mold core. The lower mold core is sequentially divided into a first injection molding area, a second injection molding area and a third injection molding area from left to right, and the surfaces, located in the first injection molding area and the third injection molding area, of the lower mold core protrude upwards to form thickening layers. According to the utility model, through the arrangement of the thickening layer, that is, the two sides of the lower mold core are thickened, so that the injection molding liquid in the thickened area flows faster, the injection molding liquid in the non-thickened area flows slower, and the injection molding liquid is convenient to fill the injection molding space formed by the injection molding area I, the injection molding area II, the injection molding area III and the upper mold core at the same time, so that the injection molding pressure is reduced; and indentations formed on the injection molding product due to resilience of the ejector pin are avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of injection molds, in particular to an injection mold with no stress marks on the product surface. Background Art

[0002] An injection mold is a tool for producing plastic products; it is also a tool for giving plastic products a complete structure and precise dimensions. Injection molding is a processing method used when mass-producing some complex-shaped parts. Specifically, it means injecting the heat-melted plastic into the mold cavity under high pressure by an injection molding machine, and after cooling and solidifying, a formed product is obtained.

[0003] When currently injecting some products with irregular shapes through an injection mold, corresponding irregular-shaped mold cores need to be used to complete the injection. When the distance from a certain position on the irregular-shaped mold core to the injection port is short, the injection liquid will reach this position on the mold core first, while other areas farther from the injection port do not have the injection liquid distributed. Continuing the injection will cause the injection liquid to accumulate in the area closer to the injection port (i.e., the area where the injection liquid reaches first), resulting in a large injection pressure in this area, which will push the ejector pin in the mold back. Subsequently, the ejector pin rebounds and is likely to form indentations on the surface of the product, affecting the injection quality of the product. To solve the above problems, we propose an injection mold with no stress marks on the product surface. Summary of the Utility Model

[0004] In view of this, the purpose of the utility model is to propose an injection mold with no stress marks on the product surface to solve the problem that when the existing injection mold injects some products with irregular shapes, the injection liquid will reach a certain position first, resulting in an increase in the injection pressure at this position, and the ejector pin in the mold is easy to rebound, causing indentations to be easily formed on the product surface.

[0005] Based on the above purpose, the utility model provides an injection mold with no stress marks on the product surface, including a bottom plate and a top plate. The bottom plate is fixedly installed with a lower template through a mold corner, and a lower mold core is arranged in the lower template. The top plate is fixedly installed with an upper template, and an upper mold core is arranged in the upper template. The lower mold core is divided into an injection area 1, an injection area 2, and an injection area 3 from left to right. The surfaces of the lower mold core in the injection area 1 and the injection area 3 bulge upward to form thickened layers. An arc-shaped groove located in the injection area 2 is opened at the bottom of the lower mold core, and a buffer structure is arranged in the arc-shaped groove.

[0006] Preferably, the thickened layer and the lower mold core are integrally formed.

[0007] Preferably, the buffer structure includes a buffer plate, and the buffer plate is fixedly connected in the arc-shaped groove.

[0008] Preferably, the buffer plate is a rubber plate.

[0009] Preferably, a plurality of springs are fixedly connected to the buffer plate, the end portions of the springs are fixedly connected to a connecting plate, and the connecting plate is slidably disposed in the arc-shaped groove.

[0010] Preferably, the number of the springs is not less than four, and the springs with the number not less than four are equidistantly distributed on the buffer plate.

[0011] The beneficial effects of the present utility model are as follows:

[0012] First, through the arrangement of the thickening layer, the injection space formed by the first injection area and the third injection area on the lower mold core and the upper mold core is reduced. That is, by thickening the two sides of the lower mold core, the injection liquid in the thickened area flows faster, and the injection liquid in the unthickened area flows slower, which is convenient for the injection liquid to simultaneously fill the injection spaces formed by the first injection area, the second injection area, the third injection area and the upper mold core, thereby reducing the injection pressure and avoiding the formation of indentations on the injection product due to the rebound of the ejector pin.

[0013] Second, through the arrangement of the buffer structure, even if the injection liquid reaches a certain place in the second injection area first, the injection pressure at this place will increase. The increase in the injection pressure will push the ejector pin back. When the ejector pin rebounds, the rebounding ejector pin will hit the buffer structure, and the buffer structure buffers the rebounding ejector pin, avoiding the formation of indentations on the injection product due to the rebound of the ejector pin. Description of the Drawings

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0015] Figure 1 It is a schematic structural diagram of an embodiment of the present utility model;

[0016] Figure 2 It is a schematic structural diagram of the lower template and the injection product in an embodiment of the present utility model;

[0017] Figure 3 It is a schematic structural diagram of the lower mold core in an embodiment of the present utility model;

[0018] Figure 4 It is a top view of the lower mold core in an embodiment of the present utility model;

[0019] Figure 5 It is a schematic structural diagram of the lower mold core and the buffer structure in an embodiment of the present utility model.

[0020] In the figure: 1, bottom plate; 2, top plate; 3, lower template; 4, lower mold core; 5, upper template; 6, injection molding area 1; 7, injection molding area 2; 8, buffer structure; 81, buffer plate; 82, spring; 83, connecting plate; 9, injection molding area 3. Detailed implementation manner

[0021] To make the objectives, technical solutions and advantages of the present utility model clearer and more understandable, the following further elaborates on the present utility model in detail in conjunction with specific embodiments and with reference to the accompanying drawings.

[0022] It should be noted that unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present utility model should have the ordinary meanings understood by those with ordinary skills in the field to which the present utility model belongs. The "first", "second" and similar terms used in the present utility model do not denote any order, quantity or importance, but are only used to distinguish different components. The terms such as "including" or "comprising" mean that the elements or objects appearing before this term cover the elements or objects listed after this term and their equivalents, without excluding other elements or objects. The terms such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The terms such as "upper", "lower", "left" and "right" are only used to represent relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0023] As Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 shown, an injection mold for a product without stress marks on the surface includes a bottom plate 1 and a top plate 2. A lower template 3 is fixedly installed on the bottom plate 1 through a die angle, and a lower mold core 4 is arranged inside the lower template 3. A ejector pin (not shown in the figure) is also arranged between the bottom plate 1 and the lower template 3. An upper template 5 is fixedly installed on the top plate 2, and an upper mold core is arranged inside the upper template 5. The lower mold core 4 is successively divided into injection molding area 1 6, injection molding area 2 7 and injection molding area 3 9 from left to right. There is a point A on injection molding area 1 6, a point B on injection molding area 2 7, and a point C on injection molding area 3 9.

[0024] In this application, since the shape of the lower mold core 4 is irregular and the distance from point B on the injection molding area 2 to the injection port is relatively close, when the injection liquid reaches point B, there is no injection liquid at points A and C. That is, the injection liquid will reach point B first. When the injection liquid continues to be filled to make points A and C full of injection liquid, there will be an accumulation of injection liquid at point B, increasing the injection pressure at point B, which will push the ejector pin back, and then the ejector pin will rebound, easily forming ejector pin marks on the surface of the injection molded product.

[0025] The lower die insert 4 has a thickened layer protruding upward on the surfaces of the first injection zone 6 and the third injection zone 9. An arc-shaped groove located within the second injection zone 7 is provided at the bottom of the lower die insert 4, and a buffer structure 8 is arranged within the arc-shaped groove.

[0026] Through the setting of the thickened layer, the injection space formed between the first injection zone 6 and the third injection zone 9 on the lower die insert 4 and the upper die insert is reduced. That is, by thickening the two sides of the lower die insert 4, the injection liquid in the thickened area flows faster, while the injection liquid in the unthickened area flows slower, facilitating the injection liquid to simultaneously fill the injection spaces formed by the first injection zone 6, the second injection zone 7, the third injection zone 9 and the upper die insert. Thereby, the injection pressure is reduced, avoiding the situation where the injection liquid first fills the second injection zone 7, which leads to an increase in the injection pressure at point B in the second injection zone 7 and causes indentations on the injection product due to the rebound of the ejector pin.

[0027] In a preferred embodiment of the present utility model, the thickened layer and the lower die insert 4 are integrally formed.

[0028] In another preferred embodiment of the present utility model, the buffer structure 8 includes a buffer plate 81. The buffer plate 81 is fixedly connected within the arc-shaped groove, and the arc-shaped groove and the buffer plate 81 are located directly below the position of point B on the second injection zone 7. The buffer plate 81 is a rubber plate.

[0029] When the injection liquid first reaches the position of point B on the second injection zone 7, injection liquid will accumulate at point B, causing an increase in the injection pressure at point B. This will push the ejector pin back, and then the ejector pin will rebound. The rebounding ejector pin will strike the rubber plate, and the rubber plate buffers the rebounding ejector pin, avoiding indentations on the injection product due to the rebound of the ejector pin.

[0030] In still another preferred embodiment of the present utility model, a plurality of springs 82 are fixedly connected to the buffer plate 81. The end of the spring 82 is fixedly connected to a connecting plate 83, and the connecting plate 83 is slidably arranged within the arc-shaped groove. The number of springs 82 is not less than four, and the springs 82 with a number not less than four are equally spaced on the buffer plate 81.

[0031] Through the setting of the plurality of springs 82, the buffering effect on the rebounding ejector pin is better, further avoiding indentations on the injection product due to the rebound of the ejector pin.

[0032] Those of ordinary skill in the art should understand that the discussion of any above embodiment is only exemplary and is not intended to imply that the scope of the present utility model is limited to these examples; under the concept of the present utility model, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of the present utility model as described above, which are not provided in detail for the sake of brevity.

[0033] Embodiments of the present utility model are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. An injection mold with no stress marks on the surface of a product, comprising a bottom plate (1) and a top plate (2), wherein a lower mold plate (3) is fixedly mounted on the bottom plate (1) via a mold angle, and a lower mold core (4) is arranged in the lower mold plate (3), and an upper mold plate (5) is fixedly mounted on the top plate (2), and an upper mold core is arranged in the upper mold plate (5), characterized in that: The lower mold core (4) is divided into a first injection molding area (6), a second injection molding area (7) and a third injection molding area (9) from left to right. The surface of the lower mold core (4) located in the first injection molding area (6) and the third injection molding area (9) is convex upward to form a thickened layer. The bottom of the lower mold core (4) is provided with an arc groove located in the second injection molding area (7), and a buffer structure (8) is arranged in the arc groove.

2. The injection mold with no stress marks on the product surface according to claim 1, characterized in that: The thickened layer and the lower mold core (4) are integrally formed.

3. The injection mold with no stress marks on the product surface according to claim 1, characterized in that: The buffer structure (8) comprises a buffer plate (81), and the buffer plate (81) is fixedly connected in the arc groove.

4. The injection mold with no stress marks on the product surface according to claim 3, characterized in that: The buffer plate (81) is a rubber plate.

5. The injection mold with no stress marks on the product surface according to claim 4, characterized in that: A plurality of springs (82) are fixedly connected to the buffer plate (81), and ends of the springs (82) are fixedly connected to connecting plates (83), and the connecting plates (83) are slidably disposed in the arc-shaped grooves.

6. The injection mold with no stress marks on the product surface according to claim 5, characterized in that: The number of the springs (82) is not less than four, and the number of the springs (82) is not less than four and is distributed on the buffer plate (81) at equal intervals.

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