Forming die for rubber product with through hole

Abstract

The utility model discloses a forming die for a rubber product with a through hole, which is characterized in that a traditional mode of forming the through hole by collision of an upper die and a lower die is changed into a mode of conical surface insertion matching of a lower end bolt and an upper end bolt hole, so that the generation position of a flash is accurately transferred to the outer edge of the lower end of the through hole from the middle section in the through hole, and meanwhile, the through hole can be formed in the lower end of the through hole. The guide conical surface at the top end of the plug pin is tightly attached to the containing conical surface of the plug pin hole during die assembly to form effective surface contact sealing, so that flash can be remarkably reduced or even completely eradicated, and even if ultra-thin flash exists, the shape of the plug pin is changed from an annular shape which is difficult to process into a thin-sheet conical shape which is easy to strip, and the service life of the plug pin is prolonged. And finally, the flash can be automatically scraped along with the movement of the bolt during mold opening, or the flash can be extremely conveniently and manually cleaned by an operator, so that the influence of residual flash on the assembly and use performance of a product is thoroughly avoided, and the flash removal efficiency and the product yield are greatly improved.

Description

Technical Field

[0001] This utility model belongs to the field of rubber molding die technology, and relates to the compression molding of rubber products, specifically a molding die for rubber products with through holes. Background Technology

[0002] In the compression molding process of rubber products (such as sealing rings, cushioning pads, and miniature rollers), it is often necessary to form through holes that penetrate the product. Traditional mold designs for such through holes typically employ a mating structure, where a semi-cylindrical cavity is set on both the upper and lower mold plates. When the mold is closed, the two semi-cylindrical cavities collide to form a complete through hole cavity.

[0003] This traditional structure has an inherent drawback: at the parting line (the point where the two semi-cylindrical cavities meet), due to machining precision and mold clearance, a small amount of rubber material can be squeezed into this gap during molding, forming a ring-shaped flash (also known as overflow) located in the center of the through hole. When the diameter of the through hole is small (e.g., less than 5mm) or the hole depth is long, this internal ring-shaped flash is extremely difficult to remove. Operators usually need to use special processes such as hook needles, high-pressure water, or cryogenic shot blasting for cleaning, which is not only inefficient and labor-intensive, but also easily causes flash residue, scratches on the inner wall of the hole, and even damage to the product itself, leading to product scrap. In addition, residual flash will affect the assembly accuracy and performance of the product, especially in high-precision sealing and moving parts, where this problem is particularly prominent. Utility Model Content

[0004] To address the technical problems existing in the background art, this utility model proposes a molding die for rubber products with through holes. By setting an insert-type mold structure, it solves the technical problem of difficult removal and easy residue caused by flash generated inside the through holes in traditional compression molding of rubber products with through holes.

[0005] The objective of this utility model can be achieved through the following technical solutions:

[0006] A molding die for a rubber product with a through hole includes: an upper template, a lower template, and an insertion structure. The upper template and the lower template are adapted to be connected to form a cavity for molding the rubber product when the mold is closed. One end of the insertion structure is installed on the lower template, and the other end penetrates the cavity vertically and is inserted into the upper template, so that a through hole is formed in the rubber product in the cavity.

[0007] Furthermore, the insertion structure includes a pin and a pin hole. The pin hole is located on the upper template, one end of the pin is installed on the lower template, and the other end is adapted to be inserted into the pin hole.

[0008] Furthermore, one end of the pin inserted into the pin hole has a guide cone surface, and the pin hole has a receiving cone surface that matches the guide cone surface. The guide cone surface and the receiving cone surface fit tightly together to form a surface contact seal when the upper and lower mold plates are closed.

[0009] Furthermore, the cone angle of the guide cone surface of the pin is set to degrees to degrees.

[0010] Furthermore, the pin is installed on the lower template through the lower mold insert, and the lower mold insert and the lower template are detachably fastened together. The pin hole is opened on the independent upper mold insert, and the upper mold insert is detachably fastened to the upper template.

[0011] Furthermore, the upper template has an upper blind hole, and the upper mold insert is installed in the upper blind hole by interference fit. A first sealing ring is provided between the upper mold insert and the wall of the upper blind hole. The lower template has a lower blind hole, and the lower mold insert is installed in the lower blind hole by interference fit. A second sealing ring is provided between the lower mold insert and the wall of the lower blind hole.

[0012] Furthermore, the end of the pin that connects to the lower mold insert has an insertion part, which is inserted into the lower blind hole and connected to the lower mold insert. The insertion part is sealed to the hole wall of the lower blind hole through the second sealing ring.

[0013] Furthermore, the lower mold insert includes a piston rod and a screw rod. The piston rod is slidably connected in the lower blind hole. The insertion part of the pin is provided with a screw hole. One end of the screw rod is fixedly connected to the piston rod, and the other end is threadedly connected in the screw hole.

[0014] Furthermore, the pin and the lower template are elastically connected by an elastic element, which is set in the lower blind hole. One end of the lower blind hole is connected to the bottom surface of the lower blind hole, and the other end is connected to the lower mold insert.

[0015] Furthermore, multiple insertion structures are provided to form a rubber product with multiple through holes, and each through hole of the rubber product is provided with an independent insertion structure.

[0016] The beneficial effects of this utility model are as follows: The molding die for rubber products with through holes provided in this application solves the technical problem of difficult removal and easy residue caused by flash generated inside the through hole in traditional compression molding of rubber products with through holes by setting an insert-type mold structure. By changing the traditional method of forming through holes by upper and lower molds, a form of tapered insertion and fit between the lower pin and the upper pin hole is adopted. The flash generation position is accurately transferred from the middle section inside the through hole to the outer edge of the lower end of the through hole. At the same time, the guide tapered surface of the pin top and the receiving tapered surface of the pin hole fit tightly when the mold is closed, forming an effective surface contact seal. This not only significantly reduces or even eliminates the generation of flash, but also changes the shape of even very thin flash from a difficult-to-handle ring to a thin tapered sheet that is easy to peel off. Finally, the flash can be automatically scraped off with the movement of the pin when the mold is opened, or can be manually cleaned by the operator with great convenience. This completely avoids the impact of flash residue on product assembly and performance, and greatly improves the efficiency of flash removal and product yield. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of this utility model.

[0018] Figure 2 This is a schematic diagram of the template of this utility model.

[0019] Figure 3 This is a schematic diagram of the lower template of this utility model.

[0020] Figure 4 This is a schematic diagram of the insertion structure of this utility model.

[0021] Figure 5 This is a schematic diagram of the pin of this utility model.

[0022] Figure 6 This is a schematic diagram of the upper mold insert of this utility model.

[0023] Figure 7 This is a schematic diagram of the lower mold insert of this utility model. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0025] like Figure 1-3As shown, this utility model provides a molding die for rubber products with through holes, including: an upper mold plate 1, a lower mold plate 2, and an insertion structure 3. The upper mold plate 1 and the lower mold plate 2 are adapted to be connected to form a cavity 4 for molding the rubber product when the mold is closed. One end of the insertion structure 3 is installed on the lower mold plate 2, and the other end penetrates the cavity 4 vertically and is inserted into the upper mold plate 1, so that a through hole is formed in the rubber product in the cavity 4. By setting the insertion structure 3 that penetrates the cavity 4 vertically and is inserted into the upper mold plate 1, this application completely transfers the internal annular flash generated by the traditional contact structure to the outside of the lower end of the through hole while molding the through hole. This makes the flash change from "difficult to reach and difficult to clean" to "accessible and easy to remove", fundamentally solving the technical bottleneck of flash residue in small through-hole rubber products and significantly improving the efficiency and thoroughness of flash cleaning. Among them, multiple insertion structures 3 can be set to mold rubber products with multiple through holes, and each through hole of the rubber product is provided with an independent insertion structure 3.

[0026] like Figure 4-5 As shown, the insertion structure 3 includes a pin 31 and a pin hole 32. The pin hole 32 is located on the upper template 1, and one end of the pin 31 is installed on the lower template 2, while the other end is adapted to be inserted into the pin hole 32. Specifically, the end of the pin 31 inserted into the pin hole 32 has a guide cone surface 33, and the pin hole 32 has a receiving cone surface 34 that cooperates with the guide cone surface 33. When the upper template 1 and the lower template 2 are closed, the guide cone surface 33 and the receiving cone surface 34 are tightly fitted together to form a surface contact seal, forming an annular conical sealing surface. This not only greatly suppresses the generation of flash, but also ensures that even if there is extremely thin flash, its shape is easily peelable. At the same time, the conical structure has a self-guiding effect when the mold is closed, improving the smoothness and centering of the mold closing and protecting the pin 31 from impact. Specifically, the cone angle of the guide cone surface 33 of the pin 31 is set to 15 to 45 degrees, which can ensure smooth mold closing and reliable sealing, and also make the thin burrs that may be generated have enough flexibility to be automatically scraped off or manually torn off.

[0027] like Figure 6-7 As shown, the pin 31 is mounted on the lower mold plate 2 via the lower mold insert 35. The lower mold insert 35 and the lower mold plate 2 are detachably fastened together. The pin hole 32 is located on an independent upper mold insert 36, which is detachably fastened to the upper mold plate 1. By setting the pin 31 and pin hole 32 on independent lower mold insert 35 and upper mold insert 36 respectively, and using a detachable connection, the maintenance and replacement of the mold are greatly facilitated. When the pin 31 or pin hole 32 wears down due to long-term use, it is not necessary to replace the expensive large mold plate; only the corresponding mold insert needs to be replaced. This significantly reduces maintenance costs and time, and improves the service life and economy of the mold.

[0028] Specifically, the upper mold plate 1 has an upper blind hole 11, and the upper mold insert 36 is installed in the upper blind hole 11 by interference fit. A first sealing ring 12 is provided between the upper mold insert 36 and the wall of the upper blind hole 11. The lower mold plate 2 has a lower blind hole 21, and the lower mold insert 35 is installed in the lower blind hole 21 by interference fit. A second sealing ring 22 is provided between the lower mold insert 35 and the wall of the lower blind hole 21. Through the double sealing design of interference fit and sealing ring, the connection strength and sealing reliability between the upper and lower mold inserts and the corresponding blind holes of the mold plates are ensured. This effectively prevents the rubber melt from seeping out from the gap between the insert and the mold plate during the molding process, forming a difficult-to-clean "drilling" problem, and ensures the cleanliness of the mold cavity and the stability of the production process.

[0029] The pin 31 has an insertion part 38 at one end that connects to the lower mold insert 35. The insertion part 38 is inserted into the lower blind hole 21 and connected to the lower mold insert 35. The insertion part 38 is sealed to the hole wall of the lower blind hole 21 through the second sealing ring 22. When the bottom surface of the insertion part 38 is connected to the lower mold insert 35, the top surface of the insertion part 38 is flush with the forming surface of the lower mold plate 2. Specifically, the lower mold insert 35 includes a piston column 351 and a screw 352. The piston column 351 is slidably connected in the lower blind hole 21. The insertion part 38 of the pin 31 is provided with a screw hole 39. One end of the screw 352 is fixedly connected to the piston column 351, and the other end is threaded into the screw hole 39, so that the pin 31 and the lower mold insert 35 form a split structure. The pin 31 is more flexible and convenient to install and remove. Pins 31 of different diameters can be flexibly installed according to the through hole size required by the rubber product.

[0030] The pin 31 is elastically connected to the lower template 2 via an elastic element 37. The elastic element 37 is located within the lower blind hole 21, with one end connected to the bottom surface of the lower blind hole 21 and the other end connected to the lower mold insert 35. By placing the elastic element 37 between the pin 31 and the lower template 2, the pin 31 becomes an elastic floating structure. During mold closing, it effectively buffers the impact between the pin 31 and the pin hole 32, preventing "mold biting" or damage caused by alignment errors. At the same time, the elastic pressure ensures that the conical sealing surface between the pin 31 and the pin hole 32 always maintains a stable contact pressure, maintaining a good sealing state even when there is slight deformation in the mold or equipment, thus improving the reliability and service life of the mold. The elastic element 37 is a disc spring assembly.

[0031] The above description is merely an example and illustration of the structure of this utility model. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the structure of the utility model or exceed the scope defined in the claims, they should all fall within the protection scope of this utility model.

Claims

1. A molding die for a rubber article with a through hole, characterized by, The utility model relates to a mould for forming rubber products with through holes, comprising: An upper die plate (1), a lower die plate (2), and a penetrating structure (3), the upper die plate (1) and the lower die plate (2) are adapted to be connected to form a cavity (4) for forming rubber products when the mould is closed, one end of the penetrating structure (3) is mounted on the lower die plate (2), the other end penetrates the cavity (4) vertically and is inserted into the upper die plate (1), so that a through hole is formed in the rubber product in the cavity (4).

2. The mold of claim 1, wherein The penetrating structure (3) comprises a bolt (31) and a bolt hole (32), the bolt hole (32) is provided on the upper die plate (1), one end of the bolt (31) is mounted on the lower die plate (2), and the other end is adapted to be inserted into the bolt hole (32).

3. The mold of claim 2, wherein, The end of the bolt (31) inserted into the bolt hole (32) has a guide taper surface (33), the bolt hole (32) has a containing taper surface (34) matched with the guide taper surface (33), and the guide taper surface (33) and the containing taper surface (34) are tightly connected to form a surface contact seal when the upper die plate (1) and the lower die plate (2) are closed.

4. The mold of claim 3, wherein The taper angle of the guide taper surface (33) of the bolt (31) is 15-45 degrees.

5. The mold of claim 2, wherein The bolt (31) is mounted on the lower die plate (2) through a lower die insert (35), the lower die insert (35) and the lower die plate (2) are detachably fastened, the bolt hole (32) is provided on a separate upper die insert (36), and the upper die insert (36) is detachably fastened to the upper die plate (1).

6. The mold of claim 5, wherein, An upper blind hole (11) is provided on the upper die plate (1), the upper die insert (36) is mounted in the upper blind hole (11) by interference fit, a first sealing ring (12) is arranged between the upper die insert (36) and the hole wall of the upper blind hole (11), a lower blind hole (21) is provided on the lower die plate (2), and the lower die insert (35) is mounted in the lower blind hole (21) by interference fit, a second sealing ring (22) is arranged between the lower die insert (35) and the hole wall of the lower blind hole (21).

7. The mold of claim 6, wherein, One end of the bolt (31) connected with the lower die insert (35) has an insertion part (38), the insertion part (38) is inserted into the lower blind hole (21) and connected with the lower die insert (35), and the insertion part (38) is sealedly connected with the hole wall of the lower blind hole (21) through the second sealing ring (22).

8. The mold of claim 7, wherein, The lower die insert (35) comprises a piston column (351) and a screw rod (352), the piston column (351) is slidably connected in the lower blind hole (21), the insertion part (38) of the bolt (31) is provided with a threaded hole (39), one end of the screw rod (352) is fixedly connected with the piston column (351), and the other end is threadedly connected in the threaded hole (39).

9. The mold of claim 6, wherein, The bolt (31) and the lower die plate (2) are elastically connected through an elastic member (37), the elastic member (37) is arranged in the lower blind hole (21), one end of the lower blind hole (21) is connected with the bottom surface of the lower blind hole (21), and the other end is connected with the lower die insert (35).

10. The mold of claim 1, wherein The penetrating structure (3) is provided with a plurality of penetrating structures, so as to form a rubber product with a plurality of through holes, and each through hole of the rubber product is provided with an independent penetrating structure (3).

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