Cable joint installation exhaust device

Abstract

The invention discloses a cable joint installation exhaust device which comprises an exhaust part, and an exhaust channel is arranged in the exhaust part. During installation, the exhaust part is firstly inserted into the inner cavity of the rubber prefabricated part, then the cable is inserted, the exhaust part is clamped between the inner cavity wall of the rubber prefabricated part and the cable inserted into the inner cavity of the rubber prefabricated part, gas sealed in the rubber prefabricated part is exhausted through the exhaust channel of the exhaust part, and the exhaust part is drawn out. The exhaust part is an exhaust strip made of an insulating high polymer material. The exhaust device can quickly and effectively exhaust gas in a closed space when a cable joint is installed, avoids generation of an air gap between a rubber prefabricated part and a cable insulation interface, and eliminates the risks of axial breakdown field strength reduction, partial discharge, influence on electric field distribution, acceleration of insulation aging and the like caused by the air gap.

Description

Technical Field

[0001] The invention relates to a cable joint installation structure, in particular to a cable joint installation exhaust device. Background Art

[0002] As the proportion of power cables in power grids increases, cables and cable accessories are experiencing more and more frequent failures due to installation problems. The removal of interface gas during the installation of cable accessories is a key factor in ensuring product quality. For plug-in structure cable accessories, there is a closed space where gas cannot be discharged. It is necessary to have a suitable method to discharge the gas at the interface between rubber preforms and cable insulation. The existence of air gaps greatly reduces the starting voltage of local discharge along the surface, weakens the role of the stress cone in evacuating the electric field, and seriously affects the interface pressure between the cone of the stress cone and the cable insulation surface, which may cause insulation breakdown and insulation surface creepage.

[0003] In order to avoid the generation of air gaps, the current method is to leave the rubber preform of the cable joint stationary for a long time after installation, and exhaust the air by means of the clamping force between the rubber preform and the cable insulation. However, the exhaust time is long and the effect is not good. Summary of the invention

[0004] The purpose of the present invention is to overcome the above-mentioned problems and provide a cable joint installation exhaust device, which can quickly and effectively exhaust the gas in the enclosed space during the installation of the cable joint, avoid the formation of air gaps at the interface between the rubber preform and the cable insulation, and eliminate the risks of reduced axial breakdown field strength, inducing local discharge, affecting electric field distribution, and accelerating insulation aging caused by the air gap.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] A cable joint installation exhaust device comprises an exhaust member, wherein an exhaust passage is provided in the exhaust member;

[0007] During the installation operation, the exhaust piece is first inserted into the inner cavity of the rubber preform, and then the cable is inserted, so that the exhaust piece is clamped between the inner cavity wall of the rubber preform and the cable inserted into the inner cavity of the rubber preform, and the gas enclosed in the rubber preform is discharged through the exhaust channel of the exhaust piece, and the exhaust piece is pulled out.

[0008] A preferred embodiment of the present invention is that the exhaust component is an exhaust strip made of an insulating polymer material; specifically, the exhaust strip is made of a composite porous material of polytetrafluoroethylene-modified PEEK and porous glass microbeads, and has a smooth surface and all sharp edges are rounded to avoid the introduction of conductive impurities and scratches on cables or joint rubber preforms during use.

[0009] The melting point of PEEK is as high as 343°C, which can maintain stable performance in high temperature environments, ensuring that the performance of the tooling is stable within the working temperature.

[0010] Excellent mechanical properties: PEEK has high strength, rigidity and toughness. The tensile strength of PEEK is usually 90-150MPa. It can withstand large mechanical stress and load and has excellent wear resistance.

[0011] Chemical resistance: It is highly resistant to a variety of chemicals, especially maintaining its chemical stability when exposed to acids, alkalis and organic solvents.

[0012] Low coefficient of friction: It has a low coefficient of surface friction and good self-lubricating properties, making it very useful in applications where wear and friction need to be reduced.

[0013] Superior electrical properties: PEEK has good electrical insulation properties and remains stable even at high temperatures.

[0014] In a preferred embodiment of the present invention, the parts where the exhaust strip contacts the rubber preforms of the cable and the joint all adopt arc structures.

[0015] In a preferred embodiment of the present invention, a mounting portion is provided at one end of the exhaust member that is not inserted into the rubber preform.

[0016] Furthermore, a pull buckle for pulling out the exhaust strip is installed on the mounting portion, and the pull buckle is connected to the mounting portion through a pin shaft.

[0017] A preferred embodiment of the present invention further comprises a vacuum pump and an exhaust pipe, one end of the exhaust pipe is connected to one end of the exhaust channel of the exhaust strip through an air pipe joint, and the other end of the exhaust pipe is connected to the vacuum pump. With the above structure, after the cable is inserted, the gas enclosed in the rubber preform can be completely exhausted by the vacuum pump.

[0018] Furthermore, the vacuum pump is a self-expanding vacuum device, the exterior of which is made of high-strength, low-permeability flexible material, and the interior is prefabricated with energy storage components such as springs. The energy storage components are compressed before leaving the factory and the end valves are closed. When used on site, a vacuum can be formed by opening the valve. It can be used in conjunction with devices of different volumes according to actual needs.

[0019] The working principle of the above cable connector installation exhaust device is:

[0020] During installation, the exhaust strip is placed into the inner hole of the rubber preform of the joint coated with lubricant, and then the cable coated with lubricant is inserted into the inner hole of the rubber preform. Since the interface pressure between the rubber preform and the cable is ensured by interference fit, a closed chamber is formed inside the rubber preform after the cable is inserted to a certain length, resulting in the inability of gas to be discharged. By setting the exhaust strip, the closed chamber and the external space can be connected, so that the air in the closed chamber can be discharged.

[0021] Furthermore, in order to prevent the lubricant applied during the insertion of the cable into the rubber preform from entering the exhaust channel of the exhaust strip, causing the exhaust channel to be blocked and unable to fully discharge the gas in the closed chamber, after the cable is fully inserted into the rubber preform, an exhaust pipe is installed on the exhaust strip, and the exhaust pipe is connected to a vacuum pump. The gas in the closed chamber is completely discharged by vacuuming, and finally the exhaust strip is pulled out of the rubber preform by a pull buckle.

[0022] In a preferred embodiment of the present invention, the exhaust member is a hollow long airbag, and one end of the hollow long airbag not inserted into the rubber preform is connected to an air pump through an air pipe;

[0023] During the installation operation, the uninflated hollow long airbag is first laid in the inner cavity of the rubber preform. After the cable is inserted, the hollow long airbag is inflated by an air pump. The hollow long airbag enters an inflated state and squeezes the inner cavity wall of the rubber preform and the outer wall of the cable. At this time, the hollow structure inside the hollow long airbag constitutes the exhaust channel.

[0024] Furthermore, one end of the hollow long airbag inserted into the rubber preform is fixedly connected with a pull-out piece, and the pull-out piece extends to the outside through the hollow structure of the hollow long airbag; when the pull-out piece pulls the hollow long airbag outward, the hollow long airbag is turned inside out and withdrawn from the rubber preform. Through the above structure, after the gas is discharged, the pull-out piece can be pulled outward to turn the hollow long airbag inside out and take it out of the rubber preform. Further, when the pull-out piece pulls the inner end of the hollow long airbag inward, the outer wall of the hollow long airbag gradually peels off from the inner cavity wall of the rubber preform and the outer wall of the cable. At this time, the hollow long airbag and the inner cavity wall of the rubber preform and the outer wall of the cable gradually do not have sliding friction, thereby greatly reducing the risk of sticky conductive particles and ensuring electrical safety. In addition, when the hollow long airbag is turned inside out. The inward-turned part will enter the hollow structure of the hollow long airbag, thereby driving the air toward the exit, further discharging the internal air to prevent the air from affecting electrical safety.

[0025] Furthermore, an air release valve is provided at one end of the hollow long airbag not inserted into the rubber preform; when the hollow long airbag is withdrawn from the rubber preform inwardly, the air release valve is opened to gradually reduce the air pressure in the hollow long airbag, and the hollow long airbag shrinks and moves outward.

[0026] Furthermore, the extraction member is a drawstring, one end of which is fixedly connected to one end of the hollow long airbag inserted into the rubber preform.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The cable joint installation exhaust device of the present invention can quickly and effectively exhaust the gas in the closed space during the installation of the cable joint, avoid the generation of air gaps at the interface between the rubber preform and the cable insulation, and eliminate the risks of reduced axial breakdown field strength, inducing local discharge, affecting electric field distribution, and accelerating insulation aging caused by the air gap. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A simplified cross-sectional view of one embodiment of installing an exhaust device for a cable joint of the present invention.

[0030] Figure 2-6 A simplified cross-sectional view showing a plurality of different working states of one embodiment of an exhaust device installed in a cable joint of the present invention.

[0031] Figure 7-9 A partially sectional schematic diagram of a plurality of different working states of another embodiment of an exhaust device for installing the cable joint of the present invention. DETAILED DESCRIPTION

[0032] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0033] Example 1

[0034] See also Figure 1 The cable connector installation exhaust device of this embodiment includes an exhaust component 1, a vacuum pump 2 and an exhaust pipe 3. The exhaust component 1 is provided with an exhaust channel 1-1; one end of the exhaust pipe 3 is connected to one end of the exhaust channel 1-1 of the exhaust component 1 through an air pipe joint, and the other end of the exhaust pipe 3 is connected to the vacuum pump 2.

[0035] During the installation operation, the exhaust piece 1 is first inserted into the inner cavity of the rubber preform 4, and then the cable 5 is inserted, so that the exhaust piece 1 is clamped between the inner cavity wall of the rubber preform 4 and the cable 5 inserted into the inner cavity of the rubber preform 4, and the gas enclosed in the rubber preform 4 is discharged through the exhaust channel 1-1 of the exhaust piece 1, and the exhaust piece 1 is pulled out.

[0036] Furthermore, the exhaust piece 1 is an exhaust strip made of an insulating polymer material; specifically, the exhaust strip is made of a composite porous material of polytetrafluoroethylene-modified PEEK and porous glass microbeads, and its surface is smooth, and all sharp edges are rounded to avoid the introduction of conductive impurities and scratches on the cable 5 or the joint rubber preform 4 during use.

[0037] The melting point of PEEK is as high as 343°C, and it can maintain stable performance in high temperature environments, ensuring that the tooling will not be unstable within the working range.

[0038] Excellent mechanical properties: PEEK has high strength, rigidity and toughness. The tensile strength of PEEK is usually 90-150MPa. It can withstand large mechanical stress and load and has excellent wear resistance.

[0039] Chemical resistance: It is highly resistant to a variety of chemicals, especially maintaining its chemical stability when exposed to acids, alkalis and organic solvents.

[0040] Low coefficient of friction: It has a low coefficient of surface friction and good self-lubricating properties, making it very useful in applications where wear and friction need to be reduced.

[0041] Superior electrical properties: PEEK has good electrical insulation properties and remains stable even at high temperatures.

[0042] Specifically, the parts where the exhaust strip contacts the cable 5 and the rubber preform 4 of the joint all adopt arc structures.

[0043] See also Figure 1 The end of the exhaust member 1 that is not inserted into the rubber preform 4 is provided with a mounting portion 1 - 2 .

[0044] Furthermore, a pull buckle 6 for pulling out the exhaust strip is installed on the installation portion 1 - 2 , and the pull buckle 6 is connected to the installation portion 1 - 2 via a pin shaft.

[0045] Specifically, the vacuum pump 2 is a self-expanding vacuum device, which uses high-strength, low-permeability flexible materials on the outside and is prefabricated with energy storage components such as springs on the inside. The energy storage components are compressed and the end valves are closed before leaving the factory. When used on site, a vacuum can be formed by opening the valve. It can be used in conjunction with devices of different volumes according to actual needs.

[0046] See also Figure 1-6 The working principle of the cable connector installation exhaust device of this embodiment is:

[0047] During installation, place the exhaust strip into the inner hole of the rubber preform 4 of the joint coated with lubricant, such as Figure 2 Then, the cable 5 coated with lubricant is inserted into the inner hole of the rubber preform 4. Figure 3 Since the interface pressure between the rubber preform 4 and the cable 5 is ensured by interference fit, a closed chamber is formed inside the rubber preform 4 after the cable 5 is inserted to a certain length, so that the gas cannot be discharged. By setting the exhaust strip, the closed chamber and the external space can be connected, so that the air in the closed chamber can be discharged. Figure 4 .

[0048] Furthermore, in order to prevent the lubricant applied during the insertion of the cable 5 into the rubber preform 4 from entering the exhaust channel 1-1 of the exhaust strip, causing the exhaust channel 1-1 to be blocked and unable to fully exhaust the gas in the closed chamber, after the cable 5 is completely inserted into the rubber preform 4, an exhaust pipe 3 is installed on the exhaust strip, and the exhaust pipe 3 is connected to the vacuum pump 2, so that the gas in the closed chamber is completely exhausted by vacuuming. Figure 5 Finally, the exhaust strip is pulled out from the rubber preform 4 by the draw buckle 6. Figure 6 .

[0049] Example 2

[0050] See also Figure 7-9 , which is different from the embodiment 1, the exhaust member 1 of the embodiment is a hollow long airbag, and the end of the hollow long airbag not inserted into the rubber preform 4 is connected to the air pump through an inflation tube; during the installation operation, the uninflated hollow long airbag is first laid in the inner cavity of the rubber preform 4, and the cable 5 is inserted, such as Figure 7 At this time, the hollow long airbag is in a flat state, and there is almost no ventilation gap between the inner cavity wall of the extruded rubber preform 4 and the cable 5; the hollow long airbag is inflated by the air pump, and the hollow long airbag enters the inflated state and squeezes the inner cavity wall of the rubber preform 4 and the outer wall of the cable 5. At this time, the hollow structure in the hollow long airbag constitutes the exhaust channel 1-1, as shown in FIG. Figure 8 .

[0051] Furthermore, one end of the hollow long airbag inserted into the rubber preform 4 is fixedly connected with a pull-out piece 6, and the pull-out piece 6 passes through the hollow structure of the hollow long airbag and extends to the outside; when the pull-out piece 6 pulls the hollow long airbag outward, the hollow long airbag is turned inside out and withdrawn from the rubber preform 4, as shown in FIG. Fig. 9 . Through the above structure, after the gas is discharged, the extraction piece 6 can be pulled outward to turn the hollow long airbag inward and take it out from the rubber preform 4. Furthermore, when the extraction piece 6 pulls the inner end of the hollow long airbag inward, the outer wall of the hollow long airbag gradually peels off from the inner cavity wall of the rubber preform 4 and the outer wall of the cable 5. At this time, the hollow long airbag and the inner cavity wall of the rubber preform 4 and the outer wall of the cable 5 gradually do not slide and rub against each other, thereby greatly reducing the risk of sticky conductive particles and ensuring electrical safety. In addition, when the hollow long airbag is turned inward. The inverted part will enter the hollow structure of the hollow long airbag, thereby driving the air in the direction of the outlet, further discharging the internal air to prevent the air from affecting electrical safety.

[0052] Furthermore, an air release valve is provided at one end of the hollow long airbag that is not inserted into the rubber preform 4; when the hollow long airbag is withdrawn from the rubber preform 4 inwardly, the air release valve is opened to gradually reduce the air pressure in the hollow long airbag, and the hollow long airbag shrinks and moves outward.

[0053] Furthermore, the extraction member 6 is a drawstring, one end of which is fixedly connected to one end of the hollow long airbag inserted into the rubber preform 4 .

[0054] The above is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited to the above content. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A cable joint installation exhaust device, characterized in that: It includes an exhaust member, in which an exhaust passage is provided; During installation, the exhaust piece is first inserted into the inner cavity of the rubber preform, and then the cable is inserted, so that the exhaust piece is clamped between the inner cavity wall of the rubber preform and the cable inserted into the inner cavity of the rubber preform, and the gas enclosed in the rubber preform is discharged through the exhaust channel of the exhaust piece, and the exhaust piece is pulled out.

2. The cable joint installation exhaust device according to claim 1, characterized in that: The exhaust member is an exhaust strip made of insulating polymer material.

3. The cable joint installation exhaust device according to claim 2, characterized in that: The exhaust strip is made of a composite porous material of polytetrafluoroethylene-modified PEEK and porous glass microbeads.

4. The cable joint installation exhaust device according to claim 1, characterized in that: The parts where the exhaust strip contacts the rubber preforms of the cable and the joint all adopt arc structures.

5. The cable joint installation exhaust device according to claim 1, characterized in that: An installation portion is provided at one end of the exhaust member that is not inserted into the rubber preform.

6. The cable joint installation exhaust device according to claim 5, characterized in that: A pull buckle for pulling out the exhaust strip is installed on the installation portion, and the pull buckle is connected to the installation portion through a pin shaft.

7. The cable joint installation exhaust device according to claim 1, characterized in that: It also includes a vacuum pump and an exhaust pipe, one end of the exhaust pipe is connected to one end of the exhaust channel of the exhaust strip through an air pipe joint, and the other end of the exhaust pipe is connected to the vacuum pump.

8. The cable joint installation exhaust device according to claim 1, characterized in that: The exhaust member is a hollow long air bag, and the end of the hollow long air bag not inserted into the rubber preform is connected to the inflation pump through an inflation pipe; During installation, first lay the uninflated hollow long airbag in the inner cavity of the rubber preform, insert the cable, and then inflate the hollow long airbag through an air pump. The hollow long airbag enters an inflated state and squeezes the inner cavity wall of the rubber preform and the outer wall of the cable. At this time, the hollow structure inside the hollow long airbag constitutes the exhaust channel.

9. The cable joint installation exhaust device according to claim 8, characterized in that: One end of the hollow long airbag inserted into the rubber preform is fixedly connected to a pull-out piece, and the pull-out piece passes through the hollow structure of the hollow long airbag and extends to the outside; when the pull-out piece pulls the hollow long airbag outward, the hollow long airbag is turned inside out and withdrawn from the rubber preform.

10. The cable joint installation exhaust device according to claim 8, characterized in that: The end of the hollow long airbag not inserted into the rubber preform is provided with a deflation valve; when the hollow long airbag is withdrawn from the rubber preform inwardly, the deflation valve is opened to gradually reduce the air pressure in the hollow long airbag, and the hollow long airbag shrinks and moves outward.

Images