Double-color mold capable of solving stress marks

Abstract

The utility model relates to a two-color mould capable of solving stress marks, which comprises a first-color mould and a second-color mould, a first mould core is arranged on a first-color front mould, a second mould core is arranged on a second-color front mould, a first rear mould and a second rear mould are respectively provided with a raised baffle table, and the first-color mould and the second-color mould are respectively provided with a second baffle table. The first mold core and the rear mold are closed to form a first cavity for injection molding of a sheet, a separation rib is arranged on the side, corresponding to the blocking table, of the first mold core and makes contact with one side of the blocking table, a vacant area is formed between the top of the blocking table and the first mold core, and a second cavity for injection molding of a button shell is defined by the first rear mold with the sheet and the second mold core. By the adoption of the technical scheme, according to the double-color mold capable of solving the stress marks, glue is added to the top of the blocking table through the one-color material, so that the two-color material does not make direct contact with steel of the rear mold, it is guaranteed that the heat conduction coefficient and the thermal expansion coefficient of the top face are consistent as much as possible, and stress concentration is avoided; and the problem of stress marks on the surface of the product is fundamentally solved.

Description

Technical Field

[0001] The utility model relates to the technical field of injection molds, in particular to a two-color mold capable of solving stress marks. Background Art

[0002] With the development of the automobile industry, people have higher requirements for the high-end, technological and lightweight design of automobiles, and the application rate of two-color injection molding technology is getting higher and higher.

[0003] like Figure 1 The product shown is an important component of the rearview mirror adjustment switch assembly. This type of product is an exposed part, and the surface is required to be high-gloss electroplated. The product surface is not allowed to have any appearance defects such as shrinkage, stress marks, and air entrapment. For two-color products with both working indicator lights and backlit characters, in order to prevent light from crossing between the indicator and the characters, a light-shielding area is required in the middle area ( Figure 2 The light-shielding area shown in C in the middle) forms an interlaced structure with the inner shell. This structural design makes the intersection of the contact area between the first and second color materials and the contact area between the second color and the mold steel material, resulting in stress marks on the product surface ( Figure 1 B in the figure shows stress marks). The fundamental reasons for stress marks are: 1. Uneven temperature distribution. Because the high-temperature melt in the light-shielding area contacts the colder mold steel, the melt temperature drops sharply and the cooling rate increases greatly. However, the surrounding melt contacts the same color material and has a higher temperature, causing the colder area to solidify and shrink before the hotter area, resulting in uneven internal stress in the product. 2. The thermal expansion coefficient (CTE) and thermal conductivity coefficient (HTC) of plastics and steel themselves are very different, resulting in large shrinkage and temperature differences, which in turn cause uneven internal stress in the product. Summary of the invention

[0004] Purpose of the utility model: In order to overcome the defects of the prior art, the utility model provides a two-color mold that can solve the problem of stress marks. A light-isolating area is provided on the injection molded product. Under the premise of not affecting the structural function, a single-color material is used for gluing in the light-isolating area so that the light-isolating area is not in direct contact with the steel of the rear mold, so that the thermal conductivity coefficient and thermal expansion coefficient of the product are as consistent as possible, avoiding stress concentration, fundamentally solving the problem of stress marks on the product surface, effectively improving product quality and injection molding yield, reducing the total manufacturing cost, and achieving the purpose of reducing costs and increasing efficiency.

[0005] The technical solution of the utility model: a two-color mold that can solve stress marks, including a first color mold and a second color mold, the first color mold including a first front mold and a first rear mold, the second color mold including a second front mold and a second rear mold, the first rear mold and the second rear mold can interchange positions, and is characterized in that a first mold core is provided on the first color mold, a second mold core is provided on the second color mold, and a raised baffle is provided on the first rear mold and the second rear mold. The first mold core and the rear mold are combined to form a first cavity for injection molding a sheet material, a dividing rib is provided on a side of the first mold core corresponding to the baffle, the dividing rib is in contact with one side of the baffle, and a vacant area is formed between the top of the baffle and the first mold core. After the first rear mold and the second rear mold are interchanged, the first rear mold with the sheet material and the second mold core form a second cavity for injection molding a button shell.

[0006] By adopting the above technical scheme, the height of the dividing rib protruding from the first mold core is greater than the height of the baffle protruding from the rear mold. When the first front mold and the first rear mold are closed, the side of the dividing rib contacts the baffle, and the first mold core forms a vacant area above the baffle. The one-color material is glued in the vacant area to form a filling part, so that the sheet formed by injection molding can cover the top of the baffle. When the first rear mold and the second front mold are closed, the top of the first rear mold is covered with the sheet, and the filling part covers the top of the baffle, ensuring that when the top surface of the button shell is injection molded, the two-color material is in contact with the one-color material, and the thermal conductivity coefficient and thermal expansion coefficient of the one-color and the two-color are as consistent as possible, thereby avoiding stress marks caused by different temperature distribution when the two-color material and the rear mold steel are in contact due to the different physical properties of the two-color material and the rear mold steel, effectively improving product quality and injection molding yield.

[0007] The utility model is further configured as follows: the baffle is arranged in an arc shape, the dividing rib is arranged in an arc shape on one side corresponding to the baffle, and the dividing rib is located on one side of the vacant area to form an arc-shaped side wall.

[0008] With the above further arrangement, the dividing ribs are arranged in an arc shape corresponding to the baffle, so that when the first front mold and the first rear mold are closed, the side surfaces of the two can be completely fitted together, and the dividing ribs become the side walls of the vacant area, ensuring that the edges of the filling parts of the injection molding are neat, which is convenient for the next injection molding operation.

[0009] The utility model is further configured as follows: a first flow channel is provided in the first color mold, and the first flow channel corresponds to one first mold core and is provided with two glue outlets which are respectively located on both sides of the separation rib.

[0010] With the above further arrangement, the two glue outlets are used for injection molding of the first sheet material and the second sheet material respectively, and the two glue outlets are used for injection molding simultaneously, thereby improving production efficiency.

[0011] The utility model is further configured as follows: a second flow channel is provided in the second color mold, the second flow channel is provided with a glue outlet communicated with the second cavity, and the glue outlet is bent and corresponds to the side surface of the second cavity.

[0012] With the above further arrangement, the bent glue outlet of the second flow channel corresponds to the side surface of the second cavity, which facilitates the rapid injection molding of the entire button housing, has a simple structure and a reasonable design.

[0013] The utility model is further configured as follows: an ejection structure is provided at the bottom of the first color mold and the second color mold, the ejection structure includes a telescopic ejector pin and an ejector plate for driving the ejector pin to move, the ejector plate can move up and down, the ejector pin includes a round ejector pin and a flat head ejector pin arranged outside the round ejector pin, and the position of the flat head ejector pin is arranged to correspond to the outer contour of the button housing.

[0014] With the above further configuration, when the product on the second color mold is injection molded, the ejector plate at the bottom of the mold moves upward, driving the ejector to eject the product. The second color mold is also provided with a spring for resetting the ejector plate. The ejector plate is reset to bring back the ejector, and the ejector retracts into the rear mold. The ejector includes three round ejector pins and six flat head ejector pins. The flat head ejector pins are arranged on the periphery of the round ejector pins to facilitate the ejection of the button housing. The round ejector pins are arranged in the middle of the product to prevent the single color product from sticking to the rear mold during ejection. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The product structure diagram of the prior art;

[0016] Figure 2 A cross-sectional view of a product of the prior art;

[0017] Figure 3 It is a structural diagram of a specific embodiment of the utility model;

[0018] Figure 4 It is a cross-sectional view of the first color mold in the utility model;

[0019] Figure 5 This is a structural diagram of the first mold core and the baffle in the utility model;

[0020] Figure 6 for Figure 4 A magnified view of part A;

[0021] Figure 7 It is an exploded view of the product in this utility model;

[0022] Figure 8 It is a cross-sectional view of the product in the utility model;

[0023] Fig. 9 It is a cross-sectional view of the first flow channel in the utility model;

[0024] Fig.10 It is a cross-sectional view of the second flow channel in the utility model;

[0025] Fig.11 It is a structural diagram of the ejection structure in the utility model;

[0026] Fig.12 It is the structural diagram of the ejector in the utility model.

[0027] In the figure: 1. first color mold; 11. first mold core; 12. dividing rib; 13. first flow channel; 131. glue outlet; 2. second color mold; 21. second flow channel; 3. baffle; 4. sheet; 41. first sheet; 42. second sheet; 41. filling area; 5. button housing; 51. light-isolating area; 52. light-isolating rib; 61. ejector; 62. ejector plate; 63. spring. DETAILED DESCRIPTION

[0028] The technical scheme in this embodiment will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of them. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0029] It should be noted that in the description of the present invention, all directional indications (such as up, down, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0030] In addition, the descriptions of "first", "second", etc. in the present invention are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. In the description of the present invention, the meaning of "several" is at least two, such as two, three, etc., unless otherwise clearly and specifically limited.

[0031] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that technical personnel in this field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0032] like Figure 1-12As shown, the utility model is a two-color mold that can solve stress marks, including a first color mold 1 and a second color mold 2, the first color mold 1 includes a first front mold and a first rear mold, the second color mold 2 includes a second front mold and a second rear mold, the first rear mold and the second rear mold can be interchanged, the first color mold 1 is provided with a first mold core 11, the second color mold 2 is provided with a second mold core, the first rear mold and the second rear mold are provided with a raised stop 3, the first mold core 11 and the first rear mold are combined to form a first cavity for injection molding a sheet 4, the first mold core 11 is provided with a partition rib 12 on the side corresponding to the stop 3, the partition rib 12 is in contact with one side of the stop 3, the top of the stop 3 and the first mold core form a vacant area, a color material is used to fill the vacant area with glue to form a filling area 41 of the sheet 4, after the first rear mold and the second rear mold are interchanged, the first rear mold with the sheet 4 and the second mold core form a second cavity for injection molding a button housing 5.

[0033] The height of the partition rib 12 protruding from the first mold core is greater than the height of the baffle 3 protruding from the rear mold. When the first front mold and the first rear mold are molded together, the side of the partition rib 12 contacts the baffle 3, and the first mold core 11 forms a vacant area above the baffle 3. The one-color material is glued in the vacant area to form a filling part 41. The thickness of the filling area 41 is 0.5mm, so that the sheet 4 formed by injection molding can cover the top of the baffle 3. When the first rear mold and the second front mold are molded together, the top of the first rear mold is covered with the sheet 4, and the filling part 41 covers the top of the baffle 3, ensuring that when the top surface of the button shell 5 is injection molded, the two-color material is in contact with the one-color material, and the thermal conductivity coefficient and thermal expansion coefficient of the one-color and the two-color are as consistent as possible, thereby avoiding stress marks caused by uneven temperature distribution when the two-color material and the rear mold steel are in contact due to their different physical properties, effectively improving product quality and injection molding yield.

[0034] like Figure 5-7 As shown, the baffle 3 is arranged in an arc shape, and the dividing rib 12 is also arranged in an arc shape on the side corresponding to the baffle 3. When the first front mold and the first rear mold are closed, the side surfaces of the two can be completely fitted together. The dividing rib 12 is located on one side of the vacant area to form an arc-shaped side wall, ensuring that the edge of the injection-molded filling part 41 is neat, which is convenient for the next injection molding operation.

[0035] like Fig. 9 As shown, a first flow channel 13 is provided in the first color mold 1. The first flow channel 13 corresponds to a first mold core 11 and is provided with two glue outlets 131 respectively located on both sides of the dividing rib 12. The two glue outlets 131 are respectively used for injection molding of the first sheet 41 and the second sheet 42. The two glue outlets 131 are injected simultaneously to improve production efficiency.

[0036] like Fig.10As shown, a second flow channel 21 is provided in the second color mold 2. The second flow channel 21 has a glue outlet communicated with the second cavity. The glue outlet is bent and corresponds to the side of the second cavity, which is convenient for rapid injection molding of the entire button shell. The structure is simple and the design is reasonable.

[0037] like Fig.11 , 12 As shown, both the first color mold 1 and the second color mold 2 are provided with an ejection structure at the bottom, which includes a retractable ejector pin 61 and an ejector plate 62 for driving the ejector pin 61 to move. The ejector plate 62 can move up and down. After the product on the second color mold 2 is injection molded, the ejector plate 62 at the bottom of the mold moves upward, driving the ejector pin 61 to eject the product. The second color mold 2 is also provided with a spring 63 for resetting the ejector plate 62. The ejector plate 62 is reset and brings back the ejector pin 61, and the ejector pin 61 is retracted into the rear mold. The ejector pin 61 includes three round ejector pins and six flat head ejector pins. The flat head ejector pins are arranged on the periphery of the round ejector pins and correspond to the outer contour of the button housing 5, so as to facilitate ejection of the button housing 5 after injection molding. The round ejector pins are arranged in the middle of the product, so as to prevent the single color product from sticking to the rear mold during ejection.

Claims

1. A two-color mold capable of solving stress marks, comprising a first color mold (1) and a second color mold (2), wherein the first color mold (1) comprises a first front mold and a first rear mold, and the second color mold (2) comprises a second front mold and a second rear mold, and the first rear mold and the second rear mold can be interchanged, characterized in that: The first color mold (1) is provided with a first mold core (11), the second color mold (2) is provided with a second mold core, the first rear mold and the second rear mold are both provided with a raised stopper (3), the first mold core (11) and the rear mold are combined to form a first cavity for injection molding a sheet material (4), a separation rib (12) is provided on the side of the first mold core (11) corresponding to the stopper (3), the separation rib (12) is in contact with one side of the stopper (3), and a vacant area is formed between the top of the stopper (3) and the first mold core (11), and after the first rear mold and the second rear mold are interchanged, the first rear mold with the sheet material (4) and the second mold core form a second cavity for injection molding a button housing (5).

2. A two-color mold capable of solving stress marks according to claim 1, characterized in that: The retaining platform (3) is arranged in an arc shape, and the dividing rib (12) is also arranged in an arc shape on a side corresponding to the retaining platform (3). The dividing rib (12) is located on one side of the vacant area to form an arc-shaped side wall.

3. A two-color mold capable of solving stress marks according to claim 1 or 2, characterized in that: The first color mold (1) is provided with a first flow channel (13), and the first flow channel (13) corresponds to a first mold cavity and is provided with two glue outlets (131) communicating therewith, and the two glue outlets (131) are respectively located on both sides of the separation rib (12).

4. A two-color mold capable of solving stress marks according to claim 1 or 2, characterized in that: A second flow channel (21) is provided in the second color mold (2), and the second flow channel (21) is provided with a glue outlet communicated with the second cavity, and the glue outlet is arranged in a curved manner and corresponds to the side surface of the second cavity.

5. A two-color mold capable of solving stress marks according to claim 1 or 2, characterized in that: The first color mold (1) and the second color mold (2) are both provided with an ejection structure at the bottom, the ejection structure comprising a telescopic ejector pin (61) and an ejector plate (62) for driving the ejector pin to move, the ejector plate (62) being movable up and down, the ejector pin (61) comprising a round ejector pin and a flat-head ejector pin arranged outside the round ejector pin, the position of the flat-head ejector pin being arranged to correspond to the outer contour of the button housing.

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