A mold for producing open ended hollow tubes

Abstract

The utility model belongs to optical communication accessory manufacturing technical field especially relates to a mould for producing open type empty pipe. A mould for producing open type empty pipe, including inner mould and be used for defining the outer contour of empty pipe outer mould, the outer mould with the inner mould cooperation to form the mould cavity for extruding the empty pipe, the outer mould has a along material extrusion direction extension's shaped piece, the shaped piece is used in the empty pipe from the mould extrusion after to the cooling before setting, to the open contour of empty pipe carries out the physical support and maintains, to prevent the empty pipe because material shrinkage leads to its open close.

Description

Technical Field

[0001] This utility model belongs to the field of optical communication accessory manufacturing technology, and in particular relates to a mold for producing open-type hollow tubes. Background Technology

[0002] With the rapid development of the information age, high-speed, high-capacity fiber optic communication networks have become an indispensable infrastructure in modern society. Fiber optics, with its significant advantages such as high transmission bandwidth, low loss, and strong resistance to electromagnetic interference, is gradually extending from backbone networks and metropolitan area networks to access networks and even user terminals, with the penetration rate of Fiber to the Home (FTTH) increasing daily. In indoor environments, whether in new buildings or renovations of existing buildings, the demand for aesthetically pleasing, convenient, and efficient fiber optic cabling solutions is becoming increasingly urgent. Traditional indoor cabling methods, such as surface-mounted wiring or the use of opaque cable trays, often fail to meet the cleanliness and aesthetic requirements of modern homes and offices, especially in scenarios where "invisible" cabling is desired. Therefore, developing new, concealed, or miniaturized fiber optic cabling technologies that can harmoniously integrate with the indoor environment has become a focus of industry attention.

[0003] To achieve concealed fiber optic cabling indoors and facilitate future maintenance and upgrades, the industry has explored various technical approaches. For example, micro-fiber optic cables or single tight-buffered fibers can be directly adhered to concealed locations such as wall corners and baseboards. However, this method becomes cumbersome when multiple fibers need to be laid, and repeated application can easily leave indelible marks and damage to the wall surface. More importantly, directly exposed or thinly protected fibers are very fragile and easily break due to impacts and pressure in daily life, affecting communication quality. Another approach is to pre-install or retrofit micro-duct systems, fixing the ducts first and then guiding the fiber optic cable in using blow-through or pulling methods. This method offers some protection for the fiber optic cable, but in terms of duct selection, if completely enclosed ducts are used, subsequent cable installation may require specialized tools, and if the ducts are not transparent, optimal concealment cannot be achieved. Using ducts with pre-existing openings presents new challenges.

[0004] In the production of open-ended hollow tubes for housing optical fibers, especially in scenarios where good transparency is desired for an "invisible" effect, plastic extrusion molding is commonly used. However, many thermoplastic materials suitable for making transparent hollow tubes (such as PVC and PA) undergo significant volume shrinkage after extrusion from the high-temperature die and before complete cooling and solidification in a cooling water bath. For hollow tubes with open cross-sections (e.g., C-shaped, G-shaped, or other non-closed shapes), this material shrinkage effect easily leads to changes in the dimensions of the opening, resulting in narrowing of the opening width, inward curling of the edges, or even complete closure. This deformation not only makes subsequent optical fiber insertion difficult or impossible but also severely affects the product yield and dimensional accuracy. Therefore, effectively controlling the shape stability of open-ended hollow tubes during the critical stage after leaving the die and before cooling and solidification in the extrusion molding process, ensuring that the opening profile meets design requirements, and preventing opening deformation or closure due to the inherent shrinkage characteristics of the material is a practical technical problem that urgently needs to be solved in this field. Utility Model Content

[0005] The purpose of this invention is to solve the above-mentioned technical problems and provide a mold for producing open-type hollow tubes.

[0006] Firstly, a mold for producing open-type hollow tubes adopts the following technical solution:

[0007] A mold for producing an open-ended hollow tube includes an inner mold and an outer mold for defining the outer contour of the hollow tube. The outer mold cooperates with the inner mold to form a cavity for extruding the hollow tube. The outer mold has a forming sheet extending along the material extrusion direction. The forming sheet is used to physically support and maintain the open contour of the hollow tube after it is extruded from the mold and before it cools and solidifies, so as to prevent the opening of the hollow tube from closing due to material shrinkage.

[0008] Furthermore, the forming sheet is a solid structure with an outer forming surface extending along the material extrusion direction, used to limit the inner surface contour of the hollow tube, and serves as a direct contact forming guide for the inner wall and / or opening edge of the hollow tube after it is extruded from the mold and before it cools and solidifies.

[0009] Furthermore, the outer molding surface of the molding sheet and the extrusion die of the outer mold together form an extrusion channel with a preset opening for molding the hollow tube.

[0010] Furthermore, the length of the formed sheet extending from the end of the extrusion die of the outer mold along the material extrusion direction is 5cm-10cm.

[0011] Furthermore, the forming piece and the outer mold are designed and manufactured as an integral unit; or, the forming piece is detachably fixedly installed on the main body of the outer mold.

[0012] Furthermore, a diameter-forming tube section is provided at the extrusion die of the outer mold. One end of the diameter-forming tube section is connected to the forming sheet, and the other end is connected to the mold cavity. The length of the diameter-forming tube section is 4mm-10mm.

[0013] Furthermore, the mold also includes multiple positioning pins and shims; the positioning pins are used to precisely align and detachably connect the inner mold and the outer mold; the shims are disposed between the inner mold and the outer mold, and the mold spacing between the inner mold and the outer mold can be precisely adjusted by adjusting the number of shims.

[0014] Secondly, an open-type hollow pipe adopts the following technical solution:

[0015] An open-type hollow tube, said open-type hollow tube is formed by extrusion and cooling using the aforementioned mold.

[0016] Furthermore, the hollow tube has an internal cavity extending along the length of the tube body, and an opening groove communicating with the internal cavity.

[0017] The beneficial effects of this utility model are:

[0018] This invention provides a mold for open-ended hollow tubes. Through its forming sheet extending along the material extrusion direction, it directly and effectively solves the technical problem of deformation or closure of the opening due to material shrinkage after extrusion and before cooling and setting. The forming sheet provides continuous physical support and shape maintenance to the opening profile of the hollow tube immediately after it leaves the high-temperature die, when the material is still soft and easily deformable and the shrinkage effect is most significant. This effectively counteracts the material's own shrinkage force, ensuring that the opening of the hollow tube maintains its designed size and geometry throughout the critical transition period from extrusion through the die to solidification in the cooling water bath, without narrowing, curling, or complete closure. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the mold structure;

[0020] Figure 2 This is a schematic diagram of the structure of a shaped sheet;

[0021] Figure 3 This is a schematic diagram of another type of molded sheet;

[0022] Figure 4 This is a schematic diagram of the structure of an empty tube;

[0023] Figure 5 This is a schematic diagram of another type of empty tube;

[0024] Figure 6 This is a schematic diagram of the connection between an optical fiber and an empty tube.

[0025] Figure 7 This is a schematic diagram illustrating the combination of an optical fiber and another type of hollow tube.

[0026] Reference numerals: 1. Mold; 10. Inner mold; 20. Outer mold; 201. Extrusion die; 202. Extrusion channel; 30. Mold cavity; 40. Forming sheet; 401. Outer forming surface; 50. Diametered pipe section; 60. Positioning pin; 70. Gasket; 2. Empty pipe; 210. Pipe body; 220. Internal cavity; 230. Opening slot; 3. Optical fiber. Detailed Implementation

[0027] The following detailed description, in conjunction with embodiments, provides a further specific account of a mold for producing open-type hollow tubes according to this utility model. For the sake of simplicity, this document cannot exhaustively list all alternative technical features and implementation schemes included in this utility model. Therefore, those skilled in the art should understand that any technical feature and implementation scheme within this embodiment does not limit the scope of protection of this utility model, which includes all alternative technical features and implementation schemes adopted by those skilled in the art without inventive effort. Specifically, any implementation scheme obtained by replacing any technical feature in this utility model or combining any two or more technical features provided by this utility model should be within the scope of protection of this utility model.

[0028] This embodiment provides a mold 1 for producing an open-type hollow tube 2, including an inner mold 10 and an outer mold 20 for defining the outer contour of the hollow tube 2. The outer mold 20 cooperates with the inner mold 10 to form a mold cavity 30 for extruding the hollow tube 2. The outer mold 20 has a forming sheet extending along the material extrusion direction. The forming sheet is used to physically support and maintain the opening contour of the hollow tube 2 after it is extruded from the mold 1 and before it cools and solidifies, so as to prevent the opening of the hollow tube 2 from closing due to material shrinkage.

[0029] This embodiment provides a mold 1 for producing an open-ended hollow tube 2. The mold 1 includes an inner mold 10 and an outer mold 20 for defining the outer contour of the hollow tube 2. The outer mold 20 and the inner mold 10 are precisely fitted together to form a mold cavity 30 for extruding molten plastic (such as transparent PVC) to form the open-ended hollow tube 2.

[0030] The key feature is that the outer mold 20 has a forming sheet extending along the material extrusion direction at the end of its extrusion die 201. The main function of this forming sheet is to provide continuous physical support and shape maintenance for the opening profile of the hollow tube 2 after the initial outline of the hollow tube 2 is formed by extruding the molten plastic at high temperature, and before it is completely cooled and shaped in the cooling water tank (not shown in the figure, but it is a configuration of a conventional extrusion production line). This effectively prevents problems such as narrowing of the opening width, inward curling of the opening edge, or even complete closure of the opening caused by thermal shrinkage of materials such as transparent PVC during the cooling process.

[0031] Specifically, when molten PVC material is extruded through the cavity 30 between the inner mold 10 and the outer mold 20, a hollow tube 2 prototype with a specific internal space and external profile is first formed. As soon as the hollow tube 2 prototype leaves the extrusion die 201 of the outer mold 20, its opening is immediately physically constrained and guided by the extended forming sheet. The shape and size of the forming sheet are designed to precisely match and maintain the desired opening size of the hollow tube 2.

[0032] In some embodiments, the forming sheet is a solid structure having an outer forming surface 401 extending along the material extrusion direction, used to limit the inner surface profile of the empty tube 2, and serving as a direct contact forming guide for the inner wall and / or opening edge of the empty tube 2 after it is extruded from the mold 1 and before it is cooled and shaped.

[0033] In some embodiments, the forming sheet is a solid structure extending along the material extrusion direction and having an outer forming surface 401. Here, "outer forming surface 401" refers to the surface of the forming sheet solid structure that faces and directly contacts the molten material to form a portion of the inner wall of the hollow tube 2. The forming sheet solid structure protrudes or extends from a portion of the outer mold 20 in the extrusion direction. Its "outer forming surface 401" is used to define and form the inner surface profile of the open hollow tube 2, particularly in the region of the opening groove 230. When the hollow tube 2 is extruded from the mold 1 and passes through the extended forming sheet, the "outer forming surface 401" of the forming sheet acts as a direct contact shaping guide for the inner wall and / or opening edge of the hollow tube 2, thereby ensuring the dimensional accuracy and shape stability of these parts.

[0034] In some embodiments, the outer molding surface 401 of the molding sheet and the extrusion die 201 of the outer mold 20 together form an extrusion channel 202 with a preset opening for molding the hollow tube 2.

[0035] More specifically, the outer molding surface 401 of the formed sheet and the extrusion die 201 of the outer mold 20 together form a complete extrusion channel 202 with a preset opening. The outer contour of the hollow tube 2 is mainly defined by the wall of the extrusion die 201 of the outer mold 20, while the internal space of the hollow tube 2 is mainly defined by the outer molding surface 401 of the formed sheet. As a special extension of the outer mold 20, the outer molding surface 401 of the formed sheet precisely defines the inner wall shape of the opening groove 230 region and the precise width of the opening, and provides extended support for these parts.

[0036] In some embodiments, the length of the formed sheet extending from the end of the extrusion die 201 of the outer mold 20 along the material extrusion direction is 5cm-10cm.

[0037] Preferably, the length of the formed sheet extending along the material extrusion direction from the end of the extrusion die 201 of the outer mold 20 is 5cm to 10cm. This length is optimized to ensure that the opening of the empty tube 2 has sufficient time and distance to maintain a stable shape under the support of the formed sheet before reaching the cooling water tank, effectively resisting material shrinkage.

[0038] In some embodiments, the forming sheet and the outer mold 20 are manufactured as an integral part; or, the forming sheet is detachably fixed to the main body of the outer mold 20.

[0039] In one manufacturing method, the forming piece and the main body of the outer mold 20 are designed and manufactured as a single unit, for example, by precision machining directly from the same piece of mold steel. This method offers high structural strength and good positioning accuracy. In another manufacturing method, the forming piece can also be designed as a detachable component, fixed to the main body of the outer mold 20 by bolts, pins, or other fasteners, or by a self-locking design. This method facilitates individual replacement, repair, or adjustment of the forming piece for products with different opening sizes.

[0040] In some embodiments, a diameter forming tube section 50 is provided at the extrusion die 201 of the outer mold 20. One end of the diameter forming tube section 50 is connected to the forming sheet 40, and the other end is connected to the mold cavity 30. The length of the diameter forming tube section 50 is 4mm-10mm.

[0041] In some embodiments, a diameter-forming tube section 50 is provided at the extrusion die 201 of the outer mold 20. One end of the diameter-forming tube section 50 is connected to or smoothly transitions to the forming sheet, and the other end communicates with the main mold cavity 30. The length of the diameter-forming tube section 50 (or the inner diameter of the effective working area) is preferably 4 mm to 10 mm. Its function is to initially regulate and buffer the material flow before the molten material enters the forming area, which helps to stabilize the extrusion pressure and prevent damage or deformation of the thin-walled part of the mold 1 due to excessive local pressure.

[0042] In some embodiments, the mold 1 further includes a plurality of locating pins 60 and shims 70; the locating pins 60 are used to precisely align and detachably connect the inner mold 10 and the outer mold 20 coaxially; the shims 70 are disposed between the inner mold 10 and the outer mold 20, and the mold spacing between the inner mold 10 and the outer mold 20 can be precisely adjusted by adjusting the number of shims 70.

[0043] In some embodiments, the mold 1 further includes a plurality of locating pins 60 and shims 70. The locating pins 60 are used to precisely coaxially align and detachably connect the inner mold 10 and the outer mold 20, ensuring the relative positional accuracy between the inner and outer molds 20, thereby guaranteeing the uniformity of the wall thickness of the extruded tube 2. The shims 70 are disposed between predetermined contact surfaces or connecting components between the inner mold 10 and the outer mold 20. By adjusting the thickness or number of shims 70, the die gap between the inner mold 10 and the outer mold 20 can be precisely adjusted.

[0044] This embodiment provides an open-type hollow tube 2, which is formed by extrusion and cooling using a mold 1.

[0045] In some embodiments, the hollow tube 2 has an internal cavity 220 extending along the length direction of the tube body 210, and an opening groove 230 communicating with the internal cavity 220.

[0046] This embodiment provides an open-type hollow tube 2, which is manufactured by plastic extrusion and cooling shaping processes using any of the mold structures described in the previous embodiments. Specifically, the hollow tube 2 is preferably made of transparent PVC material to achieve a good invisibility effect. The hollow tube 2 has an internal cavity 220 that extends uniformly along the length of its tube body 210. In this preferred embodiment, the internal cavity 220 is square or E-shaped. The hollow tube 2 also has an opening groove 230 extending along the length of the tube body 210, connecting the internal cavity 220 with the external environment. The width of the opening groove 230 is preferably 0.4 mm.

[0047] Thanks to the specially designed mold 1, the opening groove 230 of the hollow tube 2 can maintain precise dimensions and a stable shape throughout the entire production and cooling process, without closing or irregular deformation.

[0048] Other typical dimensions of the open-type hollow tube 2 may include: a short side sheath thickness of 0.3 mm above the opening, a long side sheath thickness of 3.5 mm below the opening, a three-sided complete outer sheath wall thickness of 4.2 mm on each side, and an overall tube wall thickness of 0.5 mm. This type of hollow tube 2 can accommodate multiple optical fibers 3, for example, 64 0.4 mm PA nylon square transparent tight-buffered fibers. Its design aims to facilitate the insertion of optical fibers 3 from the opening slot 230 into the internal cavity 220, and for use in concealed wiring indoors (e.g., against a wall).

[0049] For those skilled in the art, other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations, but obvious variations or modifications derived therefrom are still within the scope of protection of the claims of this utility model.

Claims

1. A mold for producing an open-ended hollow tube, comprising an inner mold and an outer mold for defining the outer contour of the hollow tube, the outer mold cooperating with the inner mold to form a mold cavity for extruding the hollow tube, characterized in that, The outer mold has a forming sheet extending along the material extrusion direction. The forming sheet is used to physically support and maintain the opening profile of the empty tube after it is extruded from the mold and before it cools and solidifies, so as to prevent the opening of the empty tube from closing due to material shrinkage.

2. The mold for producing open-type hollow tubes according to claim 1, characterized in that, The forming sheet is a solid structure with an outer forming surface that extends along the material extrusion direction. It is used to limit the inner surface contour of the hollow tube and, after the hollow tube is extruded from the mold until it is cooled and shaped, it serves as a direct contact shaping guide for the inner wall and / or opening edge of the hollow tube.

3. The mold for producing open-type hollow tubes according to claim 2, characterized in that, The outer molding surface of the molding sheet and the extrusion die of the outer mold together form an extrusion channel with a preset opening for molding the hollow tube.

4. The mold for producing open-type hollow tubes according to claim 3, characterized in that, The length of the formed sheet extending from the end of the extrusion die of the outer mold along the material extrusion direction is 5cm-10cm.

5. A mold for producing open-type hollow tubes according to claim 4, characterized in that, The forming piece and the outer mold are designed and manufactured as an integral unit; or, the forming piece is detachably fixedly installed on the main body of the outer mold.

6. A mold for producing open-type hollow tubes according to claim 5, characterized in that, A diameter-forming tube section is provided at the extrusion die opening of the outer mold. One end of the diameter-forming tube section is connected to the forming sheet, and the other end is connected to the mold cavity. The length of the diameter-forming tube section is 4mm-10mm.

7. A mold for producing open-type hollow tubes according to claim 6, characterized in that, The mold also includes multiple positioning pins and shims; the positioning pins are used to precisely align and detachably connect the inner mold and the outer mold; the shims are disposed between the inner mold and the outer mold, and the mold spacing between the inner mold and the outer mold can be precisely adjusted by adjusting the number of shims.

8. An open-type empty pipe, characterized in that, The open-type hollow tube is obtained by extrusion and cooling molding using the mold described in any one of claims 1 to 7.

9. An open-type empty pipe according to claim 8, characterized in that, The hollow tube has an internal cavity extending along the length of the tube body, and an opening groove communicating with the internal cavity.

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