Special die sleeve for extruding polytetrafluoroethylene

Abstract

The utility model belongs to the technical field of cable production, and particularly relates to a special die sleeve for polytetrafluoroethylene extrusion, which comprises an outer die and an inner die, the outer die is integrally in a stepped cylindrical shape, the outer diameter of the front end of the outer die is larger than that of the rear end of the outer die, and the outer die is equally divided into a first outer die and a second outer die along the axial direction; the inner mold comprises a cylinder part and a disc part which are integrally formed, the outer diameter of the cylinder part is matched with the inner diameter of the outer mold, a conical cavity is formed in the cylinder part, the diameter of the front end of the conical cavity is larger than that of the rear end of the conical cavity, the disc part is located at the rear end of the cylinder part, and a discharging port is formed in the center of the disc part and communicates with the conical cavity of the cylinder part. And a nylon sleeve is arranged in the discharge hole of the disc part. The device can select a proper inner die according to the specification of an extruded cable, the application range is wide, and the inner die is convenient and fast to replace; the inner mold and the outer mold are firmly fixed, and the mold stripping quality of the polytetrafluoroethylene cable is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of cable production, and in particular relates to a special die sleeve for extruding polytetrafluoroethylene. Background Art

[0002] Electrical wires are conductors used to transmit electrical energy and are categorized as bare wire, magnet wire, and insulated wire. Bare wire, which lacks insulation, includes copper and aluminum flat wire, overhead stranded wire, and various profiles (such as profiled wire, busbars, copper and aluminum busbars). It is primarily used for outdoor overhead wiring and indoor busbars and switch boxes. Magnet wire is an insulated conductor that generates a magnetic field or induces current in a magnetic field when energized. It is primarily used for windings in motors, transformers, and other related electromagnetic equipment. Insulated wire has an outer insulating layer, typically made of a polymeric plastic such as polyvinyl chloride (PVC) or polytetrafluoroethylene (PTFE).

[0003] At present, extrusion die sleeves are often used in the extrusion process of insulated wires. However, the existing extrusion die sleeve structure is relatively simple, and the stability of the die core needs to be improved. Moreover, most die sleeves are one-piece molded structures. After long-term use, if part of the structure is damaged, it needs to be replaced as a whole, which wastes materials.

[0004] Therefore, a special die sleeve for polytetrafluoroethylene extrusion is urgently needed to solve the above problems. Utility Model Content

[0005] In response to the above-mentioned defects in the prior art, the utility model provides a special mold sleeve for polytetrafluoroethylene extrusion, including an outer mold and an inner mold. The outer mold is in the shape of a stepped cylindrical tube as a whole. The outer diameter of the front end of the outer mold is larger than the outer diameter of the rear end. The outer mold is divided into a first outer mold and a second outer mold along the axial direction; the inner mold includes an integrally formed cylindrical portion and a disc portion. The outer diameter of the cylindrical portion matches the inner diameter of the outer mold. A conical cavity is provided inside the cylindrical portion, and the diameter of the front end of the conical cavity is larger than the diameter of the rear end. The disc portion is located at the rear end of the cylindrical portion. A discharge port is provided in the center of the disc portion, and the discharge port is connected to the conical cavity of the cylindrical portion. A nylon sleeve is provided in the discharge port of the disc portion.

[0006] Optionally, the disc portion and the rear end of the outer mold are both provided with bolt holes.

[0007] Specifically, it is easy to disassemble and install.

[0008] Optionally, a protrusion is provided on the outer wall of the cylindrical portion, and a groove matching the protrusion is provided on the inner wall of the outer mold.

[0009] Specifically, after the protrusion is inserted into the corresponding groove, the disc portion and the bolt hole on the outer mold can also correspond to each other; the protrusion facilitates the positioning of the inner mold, facilitates installation and improves the overall stability.

[0010] Optionally, the nylon sleeve is made of high-temperature resistant nylon material.

[0011] Specifically, the high temperature resistant nylon material may be PA46, PA66, etc.

[0012] Optionally, a heat-insulating layer is provided on the inner wall of the conical cavity of the cylindrical portion.

[0013] Specifically, the thermal insulation layer may be made of ceramic fiberboard, which can provide the mold sleeve with good thermal insulation effect and prevent the external environment from affecting the cable ejection from the mold.

[0014] The present invention also includes other components that enable a special die sleeve for polytetrafluoroethylene extrusion to function properly, all of which are conventional technical means in the art. In addition, any device or component not specified in the present invention adopts conventional technical means in the art.

[0015] The working principle of the utility model is to select a suitable inner mold according to the diameter specification of the cable, install the first outer mold and the second outer mold in combination on the outside of the inner mold, insert the protrusions on the outer wall of the inner mold into the corresponding grooves of the outer mold to position the inner mold, and then fix the outer mold and the inner mold together by bolts. Finally, the entire mold sleeve is fixed at the extrusion port of the extruder to extrude the polytetrafluoroethylene cable.

[0016] The beneficial effects of the utility model are that a suitable inner mold can be selected according to the specifications of the extruded cable, the application range is wide, and the inner mold can be replaced quickly and conveniently; the inner mold and the outer mold are first positioned by wedging with protrusions and grooves and then fixed by bolts, which can effectively prevent the inner mold from loosening and improve the demoulding quality of the polytetrafluoroethylene cable; the outer mold adopts a split structure, and if part of it is damaged after a period of use, it only needs to be replaced partially, and the remaining part can still be used, thus eliminating material waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0019] Figure 2 for Figure 1 Exploded diagram.

[0020] Figure 3 It is a side cross-sectional view of the inner mold of the present invention.

[0021] In the figure: 1. inner mold, 2. first outer mold, 3. second outer mold, 4. cylindrical portion, 5. disc portion, 6. conical cavity, 7. discharge port, 8. nylon sleeve, 9. bolt hole, 10. bump, 11. groove, 12. insulation layer. DETAILED DESCRIPTION

[0022] The present invention is described below in conjunction with the accompanying drawings and specific embodiments of the present invention. The description herein is intended only to explain the present invention and is not intended to limit the present invention. Based on the embodiments of the present invention, any modifications, equivalent substitutions, improvements, etc. made by those skilled in the art without creative work to all other embodiments obtained based on the embodiments of the present invention shall be included within the scope of protection of the present invention.

[0023] Example

[0024] like Figure 1-3 As shown, an embodiment of the present invention provides a special mold sleeve for polytetrafluoroethylene extrusion, including an outer mold and an inner mold 1. The outer mold is in the shape of a stepped cylindrical tube as a whole. The outer diameter of the front end of the outer mold is larger than the outer diameter of the rear end. The outer mold is divided into a first outer mold 2 and a second outer mold 3 along the axial direction; the inner mold 1 includes an integrally formed cylindrical portion 4 and a disc portion 5. The outer diameter of the cylindrical portion 4 matches the inner diameter of the outer mold. A tapered cavity 6 is provided inside the cylindrical portion 4, and the diameter of the front end of the tapered cavity 6 is larger than the diameter of the rear end. The disc portion 5 is located at the rear end of the cylindrical portion 4. A discharge port 7 is provided in the center of the disc portion 5, and the discharge port 7 is communicated with the tapered cavity 6 of the cylindrical portion 4. A nylon sleeve 8 is provided in the discharge port 7 of the disc portion 5.

[0025] In addition, the disc portion 5 and the rear end of the outer mold are both provided with bolt holes 9 for easy disassembly and installation. A protrusion 10 is provided on the outer wall of the cylindrical portion 4, and a groove 11 matching the protrusion 10 is provided on the inner wall of the outer mold. After the protrusion 10 is inserted into the corresponding groove 11, the disc portion 5 and the bolt hole 9 on the outer mold can also correspond; the protrusion 10 facilitates the positioning of the inner mold 1, which is convenient for installation and can also improve the overall stability. The nylon sleeve 8 is made of high-temperature resistant nylon material, and the high-temperature resistant nylon material can be PA66. An insulation layer 12 is provided on the inner wall of the conical cavity 6 of the cylindrical portion 4. The insulation layer 12 can be made of ceramic fiberboard. The ceramic fiberboard can make the mold sleeve have good thermal insulation effect and avoid the external environment from affecting the cable demolding.

[0026] The working principle of the present invention is to select a suitable inner mold 1 according to the diameter specification of the cable, and install the first outer mold 2 and the second outer mold 3 in combination on the outside of the inner mold 1, so that the protrusion 10 on the outer wall of the inner mold 1 is inserted into the corresponding groove 11 of the outer mold to position the inner mold 1, and then the outer mold and the inner mold 1 are fixed together by bolts, and finally the entire mold sleeve is fixed at the extrusion port of the extruder to extrude the polytetrafluoroethylene cable.

[0027] While the embodiments of the present invention have been described above, the above description is intended to be illustrative, not exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A special die set for polytetrafluoroethylene extrusion, comprising an outer die and an inner die, characterized in that: The outer mold is in the shape of a stepped cylinder as a whole. The outer diameter of the front end of the outer mold is larger than the outer diameter of the rear end. The outer mold is divided into a first outer mold and a second outer mold along the axial direction; the inner mold includes an integrally formed cylindrical part and a disc part. The outer diameter of the cylindrical part matches the inner diameter of the outer mold. A conical cavity is provided inside the cylindrical part, and the diameter of the front end of the conical cavity is larger than the diameter of the rear end. The disc part is located at the rear end of the cylindrical part. A discharge port is provided in the center of the disc part, and the discharge port is connected to the conical cavity of the cylindrical part. A nylon sleeve is provided in the discharge port of the disc part.

2. The special die sleeve for polytetrafluoroethylene extrusion according to claim 1, characterized in that: Bolt holes are provided at the rear ends of the disc portion and the outer mold.

3. The special die sleeve for polytetrafluoroethylene extrusion according to claim 2, characterized in that: A convex block is arranged on the outer wall of the cylindrical portion, and a groove matching the convex block is arranged on the inner wall of the outer mold.

4. The special die sleeve for polytetrafluoroethylene extrusion according to claim 3, characterized in that: The nylon sleeve is made of high temperature resistant nylon material.

5. The special die sleeve for polytetrafluoroethylene extrusion according to claim 4, characterized in that: A heat-insulating layer is provided on the inner wall of the conical cavity of the cylindrical portion.

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