Cable joint insulation injection mold

Abstract

The utility model discloses a cable joint insulation injection mold, and mainly relates to the technical field of cable maintenance. Comprising a mold body, mounting grooves are formed in the two ends of the mold body respectively, polytetrafluoroethylene heat insulation pipes are detachably mounted in the mounting grooves, an injection molding cavity for communicating the two mounting grooves in a penetrating mode is formed between the two mounting grooves, and an electric heating plate for heating the injection molding cavity is arranged in the middle of the mold body. The heat insulation pipe comprises two heat insulation half pipes which are equally divided along the axis of the heat insulation pipe, the mold body comprises an upper shell and a lower shell which are divided along the axis of the injection molding cavity, the upper shell and the lower shell are fixed through a fastener, and injection molding holes communicated with the injection molding cavity are formed in the center of the upper shell and the center of the lower shell respectively. And exhaust holes penetrating through the upper shell are formed in the two ends of the injection molding cavity. The beneficial effects of the utility model lie in that the device can be used for field maintenance, and a closed injection molding cavity is formed at the damaged part or the joint of the cable in a surrounding manner, thereby providing preparation for glue injection repair.

Description

Technical Field

[0001] The utility model relates to the technical field of cable maintenance, in particular to an insulating injection mold for a cable joint. Background Art

[0002] For cable damage repair and joint operations, the damaged part needs to be repaired or the joint part needs to be connected, and these operations need to be completed on site.

[0003] The existing method is to use strip-shaped semi-conductive tape and polyethylene insulating tape to wrap and fill the places where the cable needs to be connected or repaired on site, and then wrap a layer of polytetrafluoroethylene high-temperature tape and copper tape on the outside, and then wrap it with a heating tape or use a torch to heat and fuse it into a whole. After this method of repair or connection, the cable's operating temperature tolerance is reduced and its life is shortened, which poses a hidden danger to subsequent operation. Utility Model Content

[0004] The utility model aims to provide an insulating injection mold for a cable joint, which can be used for on-site maintenance and encloses a closed injection mold cavity at a damaged portion of a cable or a joint, providing preparation for glue injection repair.

[0005] In order to achieve the above-mentioned purpose, the utility model is realized through the following technical solutions:

[0006] A cable connector insulation injection mold, including a mold body, both ends of the mold body are respectively provided with installation grooves, polytetrafluoroethylene insulation tubes are detachably installed in the installation grooves, an injection cavity is provided between the two installation grooves to connect the two, an electric heating plate for heating the injection cavity is provided in the middle of the mold body, the insulation tube includes two insulation half tubes equally divided along its axis, the mold body includes an upper shell and a lower shell split along the axis of the injection cavity, the upper shell and the lower shell are fixed by fasteners, the center of the upper shell and the center of the lower shell are respectively provided with injection holes connected to the injection cavity, and both ends of the injection cavity are provided with exhaust holes that penetrate the upper shell.

[0007] The electric heating plate is an arc-shaped plate coaxial with the injection cavity, and the electric heating plate is composed of two pieces, which are respectively arranged on the upper shell and the lower shell.

[0008] The thermal insulation tube includes a tube portion and a flange portion, wherein the flange portion is arranged outside the mounting groove, the diameter of the tube portion corresponds to the inner diameter of the mounting groove, and the two ends of the injection molding cavity and the mounting groove have a step structure at the connection, and the step structure is used to cooperate with the inner end face of the tube portion.

[0009] The injection molding cavity includes a middle section, a transition section, and an outer end section. The middle section is a cylindrical tube cavity located in the middle, and the outer end sections are symmetrically arranged at both ends of the injection molding cavity. The outer end sections are cylindrical tube cavities with a smaller diameter than the middle section. The diameter of the outer end sections corresponds to the inner diameter of the insulation tube. The transition section is located between the outer end section and the middle section. The inner end cross-section of the transition section is cocircular with the middle section, and the outer end cross-section of the transition section is cocircular with the outer end section.

[0010] The exhaust hole is arranged in the outer end section, and an annular groove is provided on the inner wall of the outer end section corresponding to the position of the exhaust hole. The annular groove is connected to an exhaust groove extending inward along the axis of the injection cavity, and the inner end of the exhaust groove is located at the two end edges of the middle section. Multiple exhaust grooves are respectively arranged on the upper shell and the lower shell.

[0011] The outer end of the injection hole is provided with a connecting seat protruding from the mold body, and the center of the outer end surface of the connecting seat is provided with a matching groove connected to the injection hole, and the matching groove is a cone with a larger outer side and a smaller inner side.

[0012] Compared with the prior art, the beneficial effects of the present invention are:

[0013] Based on the above structure, the mold can be used in the construction site. The split structure of the mold body and the insulation tube can be used to conveniently match the cable, and a closed injection molding cavity is obtained to provide necessary preparation for filling and molding with heat-cross-linked polyethylene molten material.

[0014] The mold body has two upper and lower injection holes, which can realize double-head injection, so as to obtain a uniform and non-eccentric wrapping layer.

[0015] The structure of the exhaust hole is conducive to combining gas protection to achieve air management and pressure control during the injection molding process.

[0016] The built-in heating function can heat the closed injection molding cavity, which is conducive to accurate temperature control in various environments. High temperature can shorten the vulcanization time, improve efficiency, and discharge bubbles. The thermal elongation after molding reaches 70-90%, which meets the standard requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is an overall schematic diagram of the utility model after assembly.

[0018] Figure 2 It is a schematic diagram of the utility model cooperating with a cable.

[0019] Figure 3 It is a schematic diagram of component disassembly of the utility model.

[0020] Figure 4 It is a schematic diagram of one end face of the utility model.

[0021] Figure 5 This utility model Figure 4 AA cross-section diagram of .

[0022] Numbers shown in the accompanying drawings:

[0023] 1. Upper shell; 2. Lower shell; 3. Insulation tube; 4. Mounting groove; 5. Step structure; 6. Middle section; 7. Transition section; 8. Outer end section; 9. Injection hole; 10. Connecting seat; 11. Matching groove; 12. Exhaust hole; 13. Annular groove; 14. Exhaust groove; 15. Strip boss; 16. Strip groove. DETAILED DESCRIPTION

[0024] The present invention is further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the present application.

[0025] The instruments, reagents, materials, etc. involved in the following embodiments, unless otherwise specified, are all conventional instruments, reagents, materials, etc. in the prior art and can be obtained through regular commercial channels. The experimental methods, detection methods, etc. involved in the following embodiments, unless otherwise specified, are all conventional experimental methods, detection methods, etc. in the prior art.

[0026] Example 1: A cable connector insulation injection mold

[0027] The mold as a whole adopts a split structure, and the damaged position is wrapped and closed on site to provide a closed cavity for injection molding.

[0028] It includes independently detachable parts: a mold body and a polytetrafluoroethylene heat insulation tube 3.

[0029] The mold body adopts a detachable structure, which is divided into two parts and connected and installed by fasteners - screws. Specifically, it includes an upper shell 1 and a lower shell 2, and the "upper" and "lower" mentioned above are the usual states when in use. The upper shell 1 and the lower shell 2 are respectively provided with mounting holes on both sides, and the mounting holes are matched with screws and nuts to fix the two.

[0030] The end face of the upper shell 1 that contacts the lower shell 2 is the upper end face, and the face of the lower shell 2 that contacts the upper shell 1 is the lower end face. The upper end face is provided with a protruding strip boss 15, and the lower end face is provided with a strip groove 16 that matches the strip boss 15. This bite-fit design can improve the sealing after fitting.

[0031] The two ends of the mold body are respectively provided with mounting grooves 4, and the insulation tube 3 is installed in the mounting grooves 4. The insulation tube 3 includes a tube part and a flange part. The flange part is arranged outside the mounting groove 4, and the tube part is fixed with the mounting groove 4. In order to directly connect with the damaged cable on site, the insulation tube 3 is also divided into two symmetrical components from its axis, which are two opposite insulation half-tubes. The insulation half-tube is used to isolate the heat in the middle, so as to avoid affecting the two sides of the damaged part of the cable, so that the heat is concentrated inside the injection cavity.

[0032] An upper cavity is provided on the end surface where the upper shell 1 and the lower shell 2 meet, and a lower cavity is provided on the end surface where the lower shell 2 and the upper shell 1 meet. The positions of the upper cavity and the lower cavity correspond to each other and their cross-sectional shapes are symmetrical, and the two enclose a complete injection molding cavity. Both ends of the injection molding cavity are connected to the mounting groove 4, and a step structure 5 is provided at the connection, and the step structure 5 is used to cooperate with the end surface of the pipe portion of the insulation pipe 3 to assist in positioning the installation of the insulation pipe 3.

[0033] The injection mold cavity includes a middle section 6, a transition section 7, and an outer end section 8;

[0034] The middle section 6 is located in the middle, there are two outer end sections 8 and they are located at both ends respectively, and the transition section 7 is located between the outer end section 8 and the middle section 6 and is symmetrically arranged relative to the middle section 6 .

[0035] The middle section 6 is a cylindrical lumen;

[0036] The transition section 7 is a truncated cone-shaped lumen, and the outer end diameter of the transition section 7 is smaller than the inner end diameter. The inner end section of the transition section 7 is cocircular with the middle section 6, and the outer end section of the transition section 7 is cocircular with the outer end section 8, so as to achieve docking of the middle section 6 and the outer end section 8.

[0037] The outer end section 8 is a cylindrical tube cavity with a diameter larger than that of the middle section 6, and the outer end section 8 is coaxial with the middle section 6. The diameter of the outer end section 8 is the same as the inner diameter of the insulation tube 3, thereby achieving matching and contact with the surface near the cable.

[0038] In specific applications, the damaged cable is repaired as follows Figure 2 After the structure and shape are formed, the upper shell 1 and the lower shell 2 are closed and placed in the injection molding cavity of the above structure, so that the part with the insulator layer is located at the outer end section 8, and the damaged position in the middle is located at the middle section 6 for repair. The outer end section 8 is used to achieve a close fit with the cables (with the insulator layer) at both ends of the damage, and the molten material is concentrated at the damaged position in the middle.

[0039] Electric heating plates are fixed in the center of the upper shell 1 and the lower shell 2, respectively, and the heating temperature is 150 degrees Celsius. The electric heating plates are arranged at the position of the middle section 6, and the electric heating plates are located on the arc plate coaxial with the cavity, for heating and maintaining the temperature.

[0040] Injection holes 9 are symmetrically provided in the center of the upper shell 1 and the center of the lower shell 2. The inner ends of the injection holes 9 are connected to the injection cavity, and are used to cooperate with the injection molding equipment to inject low-density cross-linked polyethylene material into the injection cavity. The molten material injected above and the molten material injected below are constrained by the upper cavity and the lower cavity to form a repair layer around the cable.

[0041] A connecting seat 10 is provided in the center of the end surfaces of the upper shell 1 and the lower shell 2 that are away from each other. A matching groove 11 is provided in the center of the outer end surface of the connecting seat 10 away from the mold body. The bottom of the matching groove 11 is a cone that is larger on the outside and smaller on the inside. The matching groove 11 is coaxially connected to the injection hole 9. The matching groove 11 cooperates with the injection nozzle to better introduce the molten material into the injection hole 9.

[0042] The upper shell 1 is provided with an exhaust hole 12 in communication with the outer end section 8 , and the exhaust hole 12 is used to exhaust the gas extruded when the molten material enters the injection molding cavity.

[0043] An annular groove 13 is provided on the side wall of the outer end section 8 at the position corresponding to the exhaust hole 12. The inner end of the exhaust hole 12 is located in the annular groove 13. The annular groove 13 is formed into a semicircle located on the upper shell 1 and the lower shell 2 respectively based on the bisection of the mold body. When the upper shell 1 and the lower shell 2 are closed, they form a closed ring.

[0044] The injection cavity is also provided with exhaust grooves 14 at both ends, the length direction of the exhaust groove 14 is consistent with the axis of the injection cavity, the inner end of the exhaust groove 14 is located in the transition section 7, and the outer end of the exhaust groove 14 is connected to the annular groove 13, so that the gas can be collected from the middle section 6 and gathered outward, and discharged from the exhaust hole 12 above through the series connection of the annular grooves 13.

[0045] The inner end of the exhaust groove 14 is pointed and shallow, and gradually deepens and widens as it extends outward.

[0046] The exhaust grooves 14 have two exhaust grooves at both ends of the upper shell 1 and two exhaust grooves at both ends of the lower shell 2, so there are four exhaust channels at both ends of the injection cavity, which are evenly distributed up and down, to smoothly exhaust the inert gas to the outside.

[0047] Based on the above structure, the mold can be used in the construction site. Without cutting off the cable, the split upper shell 1 and lower shell 2 are used to enclose the cable. The insulation tube 3 at both ends also adopts a half-split structure. The damaged ends are sealed and fixed by enclosing at both ends of the cable, so as to form a closed tubular cavity at the damaged position after repair, which is used to fill and mold the heat-cross-linked polyethylene molten material.

[0048] During the operation, 0.6MP compressed nitrogen (or inert gas such as carbon dioxide, argon, etc.) needs to be filled in, and the pipe wall is heated to 150 degrees Celsius using an electric heating plate. The heating is kept for 17 minutes and then stopped. When the pipe cools to below 50 degrees, the nitrogen is discharged and the upper shell 1 and the lower shell 2 are removed. At this time, the cross-linking degree index of the cross-linked polyethylene insulation - the thermal elongation reaches 70-90%, which meets the standard requirements.

[0049] Based on the above molds and operations, the cable repaired by our molds can effectively isolate dust and water vapor in the air during the sealing process, and obtain a purer insulation layer. It can also be operated on site, and the injection molding cavity can be obtained by installing it at the damaged position of the cable, which is more practical and simple to operate.

[0050] By combining nitrogen protection in the closed space of the injection molding cavity, oxygen is isolated and the surface of the insulator is prevented from oxidation and discoloration. The temperature is controlled and increased by the electric heating plate to shorten the vulcanization time. The closed injection molding cavity provides conditions for 0.6MP pressure control, so that the gas in the gap of the cable conductor will not expand into bubbles.

[0051] By heating to achieve high temperature and high pressure vulcanization, the cross-linking degree of low-density cross-linked polyethylene can be reliably met. At the same time, the cable body insulation and the post-injection insulation are fused into one, so that water vapor in the operating environment will not penetrate, ensuring the same service life of the joint and the cable body.

[0052] In addition, the mold injection process is completed through two injection holes on the upper shell and the lower shell, thereby offsetting the above-mentioned thrust and obtaining a uniform and non-eccentric wrapping layer.

Claims

1. A cable connector insulation injection mold, characterized in that: The invention comprises a mould body, both ends of which are respectively provided with mounting grooves, in which polytetrafluoroethylene heat-insulating tubes are detachably installed, an injection cavity which penetrates and connects the two mounting grooves is provided between the two mounting grooves, an electric heating plate for heating the injection cavity is provided in the middle of the mould body, the heat-insulating tube comprises two heat-insulating half-tubes which are equally divided along its axis, the mould body comprises an upper shell and a lower shell which are split along the axis of the injection cavity, the upper shell and the lower shell are fixed by fasteners, injection holes which are connected to the injection cavity are respectively provided in the center of the upper shell and the center of the lower shell, and exhaust holes which penetrate the upper shell are provided at both ends of the injection cavity.

2. The cable connector insulation injection mold according to claim 1, characterized in that: The electric heating plate is an arc-shaped plate coaxial with the injection cavity, and the electric heating plate is composed of two pieces, which are respectively arranged on the upper shell and the lower shell.

3. The cable connector insulation injection mold according to claim 1, characterized in that: The thermal insulation tube includes a tube portion and a flange portion, wherein the flange portion is arranged outside the mounting groove, the diameter of the tube portion corresponds to the inner diameter of the mounting groove, and the two ends of the injection molding cavity and the mounting groove have a step structure at the connection, and the step structure is used to cooperate with the inner end face of the tube portion.

4. The cable connector insulation injection mold according to claim 1, characterized in that: The injection molding cavity includes a middle section, a transition section, and an outer end section. The middle section is a cylindrical tube cavity located in the middle, and the outer end sections are symmetrically arranged at both ends of the injection molding cavity. The outer end sections are cylindrical tube cavities with a smaller diameter than the middle section. The diameter of the outer end sections corresponds to the inner diameter of the insulation tube. The transition section is located between the outer end section and the middle section. The inner end cross-section of the transition section is cocircular with the middle section, and the outer end cross-section of the transition section is cocircular with the outer end section.

5. The cable connector insulation injection mold according to claim 4, characterized in that: The exhaust hole is arranged in the outer end section, and an annular groove is provided on the inner wall of the outer end section corresponding to the position of the exhaust hole. The annular groove is connected to an exhaust groove extending inward along the axis of the injection cavity, and the inner end of the exhaust groove is located at the two end edges of the middle section. Multiple exhaust grooves are respectively arranged on the upper shell and the lower shell.

6. The cable connector insulation injection mold according to claim 1, characterized in that: The outer end of the injection hole is provided with a connecting seat protruding from the mold body, and the center of the outer end surface of the connecting seat is provided with a matching groove connected to the injection hole, and the matching groove is a cone with a larger outer side and a smaller inner side.

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