Temperature measuring assembly for cable joint of ring main unit

Abstract

The utility model discloses a temperature measurement assembly for a cable joint of a ring main unit, and the assembly comprises an insulating plug which is used for being connected with the cable joint; the metal nut is arranged at one end of the insulating plug; the ceramic sleeve is arranged at the other end of the insulating plug back to the metal nut, the closed end of the ceramic sleeve extends into the insulating plug, the open end of the ceramic sleeve extends out of the outer side of the insulating plug, and the closed end of the ceramic sleeve abuts against the metal nut; the temperature measuring probe is in threaded connection with the ceramic sleeve, the temperature measuring probe extends into the ceramic sleeve, the temperature measuring probe comprises an optical fiber and a fluorescent material arranged at the detection end of the optical fiber, and the detection end of the optical fiber is located in the ceramic sleeve. The assembly is simple in installation process and can accurately measure the temperature.

Description

Technical Field

[0001] The utility model belongs to the technical field of sensors, and in particular relates to a temperature measuring component for a cable joint of a ring network cabinet. Background Art

[0002] The cable connector of the ring main unit (referred to as the cable connector) is an important part of the ring main unit, which is used to connect cables to achieve power transmission and distribution. The ring main unit is a high-voltage switchgear, usually used in the ring main power supply system. They can be installed outdoors or indoors, and have different structures and designs to meet different application requirements.

[0003] Temperature monitoring of cable joints is very important for ring network power supply systems. This is because the temperature increase of cable joints may cause problems such as cable overheating and insulation aging, which in turn may lead to safety accidents or system failures. Traditional infrared thermometers detect the temperature of cable joints by installing optical fiber temperature sensors on the outside of the cable joints. Since they do not directly contact the actual heating point of the metal conductor inside the cable joint, the temperature measurement accuracy of this method is very low.

[0004] In summary, there is an urgent need to provide a temperature measuring component and a preparation method for a ring main unit cable joint, which has a simple structure, is easy to install, and is conducive to improving the temperature measurement accuracy. Utility Model Content

[0005] The purpose of the embodiment of the utility model is to provide a temperature measuring component for a cable joint of a ring main unit, which has a simple structure, is easy to install, and is conducive to improving detection accuracy.

[0006] The embodiment of the utility model provides a temperature measuring component for a cable joint of a ring main unit, and the temperature measuring component for a cable joint of a ring main unit comprises:

[0007] Insulating plug, used to connect with the cable connector;

[0008] A metal nut, disposed at one end of the insulating plug;

[0009] A ceramic sleeve, which is disposed at the other end of the insulating plug and faces away from the metal nut, wherein the closed end of the ceramic sleeve extends into the insulating plug, the open end of the ceramic sleeve extends out of the insulating plug, and the closed end of the ceramic sleeve abuts against the metal nut;

[0010] The temperature measuring probe is threadedly connected to the ceramic sleeve, the temperature measuring probe extends into the ceramic sleeve, and the temperature measuring probe includes an optical fiber and a fluorescent substance arranged at the detection end of the optical fiber, and the detection end of the optical fiber is located in the ceramic sleeve.

[0011] According to one embodiment of the utility model, the temperature measuring probe further includes:

[0012] A reinforcing member extending in a first direction, the reinforcing member having a first end and a second end opposite to each other in the first direction, and a first channel penetrating the first end and the second end is provided inside the reinforcing member;

[0013] A ceramic ferrule, one end of which is disposed in the first channel and the other end of which extends out of the first end of the reinforcement member along the first direction, a second channel being disposed inside the ceramic ferrule, and the first channel is connected to the second channel;

[0014] A ceramic end cap, wherein a chamber with one end open and the other end sealed is provided inside, wherein the end with the opening is sleeved on the outer periphery of the ceramic insert and fixed in the first channel, and the fluorescent substance is provided in the chamber of the ceramic end cap close to the sealed end;

[0015] An optical fiber sheath connected to the second end of the reinforcement member, and a third hole is provided inside the optical fiber sheath, and the third hole is communicated with the first hole;

[0016] A fastener, which is movably sleeved outside the optical fiber sheath and is used to fix the temperature measurement component;

[0017] One end of the optical fiber is arranged in the channel of the ceramic ferrule and contacts the fluorescent substance, and the other end extends along the inside of the first channel and the third channel.

[0018] According to one embodiment of the utility model, the temperature measuring assembly for the cable joint of the ring main unit further includes:

[0019] A heat shrink tube is wrapped around the outer circumference of the optical fiber sheath and the strength member to connect the optical fiber sheath and the strength member.

[0020] According to one embodiment of the utility model, the temperature measuring assembly for the cable joint of the ring main unit further includes:

[0021] A ceramic sleeve is recessed inward from one end to form a receiving cavity, the ceramic end cap, the ceramic insert and the reinforcement are placed in the receiving cavity, and the sealing end of the ceramic end cap faces the closed end of the ceramic sleeve.

[0022] According to one embodiment of the utility model, the fastener comprises:

[0023] A limiting flange, the limiting flange is used to be clamped on the port of the ceramic sleeve;

[0024] The threaded rod is connected to the limiting flange and is used for being threadedly connected to the side wall of the accommodating cavity of the ceramic sleeve.

[0025] According to an embodiment of the utility model, a boss is provided on the outer periphery of the second end of the reinforcement, and the boss is used to abut against the threaded rod when the threaded rod is screwed into the ceramic sleeve.

[0026] According to one embodiment of the utility model, the temperature measuring assembly for the cable joint of the ring main unit further comprises an insulating plug for connecting with the cable joint.

[0027] The closed end of the ceramic sleeve extends into the interior of the insulating plug, the open end extends out of the outside of the insulating plug, and the closed end of the ceramic sleeve abuts against the cable connector.

[0028] According to an embodiment of the utility model, an inwardly recessed groove is provided on the outer circumference of the ceramic sleeve, and the groove matches the inner protrusion of the insulating plug.

[0029] According to an embodiment of the utility model, the ceramic bushing and the insulating plug are integrally cast to form the ceramic bushing.

[0030] According to an embodiment of the utility model, the insulating plug, the metal nut and the ceramic sleeve are manufactured by a casting process.

[0031] According to an embodiment of the present invention, the outer surface of the closed end of the ceramic sleeve has a first plane, the outer surface of the metal nut has a second plane, and the first plane is in contact with the second plane.

[0032] In a second aspect, the utility model further discloses a method for preparing a temperature measuring component, which is applied to the temperature measuring component for the cable joint of the ring main unit in the embodiment of the first aspect, and the preparation method comprises:

[0033] Fixing the first end of the reinforcement member to the ceramic ferrule with glue, and connecting the optical fiber sheath to the second end of the reinforcement member;

[0034] Sleeve the fastener onto the outer circumference of the optical fiber sheath;

[0035] Inserting the interior of the ceramic ferrule into the optical fiber;

[0036] One end of the ceramic ferrule is coated with fluorescent material, and the ceramic end cap is placed on the ceramic ferrule and bonded to the inner wall of the first channel of the reinforcement.

[0037] As an embodiment of the second aspect, the method further includes threading the fastener with the ceramic sleeve.

[0038] The device of the embodiment of the utility model has at least the following effects:

[0039] 1. According to the embodiment of the utility model, the temperature measuring component for the cable joint of the ring main unit is integrated, and the assembly can be achieved by tightening the fastener with the ceramic sleeve pre-buried in the insulating plug, and the installation process is simple.

[0040] 2. The fastener is rotatably mounted on the outside of the optical fiber jacket, that is, the temperature measuring probe is separated. When it is tightly matched with the ceramic sleeve of the embedded part, the optical fiber will not be entangled, thus avoiding the problems of temperature measurement failure and low accuracy, which is conducive to improving the accuracy of temperature detection.

[0041] 3. There is no pre-buried optical fiber in the insulating plug, and the temperature measurement component does not contain an optical connector, which will not cause additional insertion loss and return loss.

[0042] 4. The packaging structure of the temperature measurement component of the embodiment of the utility model can better protect the optical fiber, and use the stimulated radiation of the fluorescent material to generate fluorescence with a wavelength of about a high wavelength. The fluorescence is transmitted through the optical fiber and emitted at the other end of the optical fiber. The light focused by the lens is captured by the photodetector. The captured light can achieve high-precision temperature detection by analyzing the relationship between the fluorescence curve characteristics and temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a structural schematic diagram of a temperature measuring component for a cable joint of a ring main unit according to an embodiment of the utility model.

[0044] Figure 2 This is a schematic cross-sectional view of a temperature measuring assembly for a cable joint of a ring main unit according to an embodiment of the utility model;

[0045] Figure 3 This is a structural schematic diagram of a temperature measuring assembly for a cable joint of a ring main unit according to another embodiment of the utility model;

[0046] Figure 4 A schematic cross-sectional view of a temperature measuring assembly for a cable joint of a ring main unit according to another embodiment of the utility model;

[0047] Figure 5 This is a schematic structural diagram of an insulating plug and a ceramic bushing combined in another embodiment of the present invention.

[0048] Attached photos

[0049] Temperature measuring component 100 for cable joint of ring main unit;

[0050] Reinforcement member 10; Boss 11;

[0051] Ceramic ferrule 20;

[0052] Ceramic end cap 30;

[0053] Optical fiber sheath 40;

[0054] Fastener 50; limiting flange 51; threaded rod 52;

[0055] Optical fiber 60;

[0056] Heat shrink tubing 70;

[0057] Ceramic sleeve 80; accommodating cavity 81; groove 82;

[0058] Insulating plug 90; Metal nut 91. DETAILED DESCRIPTION

[0059] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0060] The cable connector of the ring main unit (referred to as the cable connector) is an important part of the ring main unit, which is used to connect cables to achieve power transmission and distribution. The ring main unit is a high-voltage switchgear, usually used in the ring main power supply system. They can be installed outdoors or indoors, and have different structures and designs to meet different application requirements.

[0061] Temperature monitoring of cable joints is very important for ring network power supply systems. This is because the temperature increase of cable joints may cause problems such as cable overheating and insulation aging, which in turn may lead to safety accidents or system failures. Traditional infrared thermometers detect the temperature of cable joints by installing optical fiber temperature sensors on the outside of the cable joints. Since they do not directly contact the actual heating point of the metal conductor inside the cable joint, the temperature measurement accuracy of this method is very low.

[0062] In view of the above situation, the implementation mode of the present application provides a temperature measuring component and a preparation method for a ring main unit cable joint. The specific structure and working principle of the temperature measuring component 100 for a ring main unit cable joint of the utility model embodiment are described in detail below in conjunction with the accompanying drawings.

[0063] refer to Figure 1 , Figure 1 The schematic diagram of the structure of the temperature measuring assembly 100 for the cable joint of the ring main unit according to the embodiment of the utility model is shown as an example; Figure 2 It is a schematic cross-sectional structure diagram of a temperature measuring assembly 100 for a cable joint of a ring main unit according to an embodiment of the present utility model.

[0064] The first direction in the embodiment of the present invention is used to indicate the extending direction of the optical fiber 60 .

[0065] like Figure 1 The temperature measuring assembly 100 for the cable joint of the ring main unit includes a reinforcement member 10, a ceramic ferrule 20, a ceramic end cap 30, an optical fiber sheath 40, a fastener 50 and an optical fiber 60. This partial structure can also be called a temperature measuring probe.

[0066] Specifically, the reinforcement member 10 extends along a first direction, and a first channel is provided inside the reinforcement member 10 to pass through both ends. One end of the ceramic ferrule 20 is disposed in the first channel, and the other end extends out from below the reinforcement member 10 (such as Figure 1 The ceramic ferrule 20 is provided with a second channel inside, and the first channel is connected to the second channel. The ceramic end cap 30 is provided with a chamber with one end open and the other end sealed. The ceramic end cap 30 has an open end which is sleeved on the outer periphery of the ceramic ferrule 20 and fixed in the first channel, and a fluorescent substance is provided in the chamber near the sealed end of the ceramic end cap 30. The optical fiber sheath 40 is connected to the second end of the reinforcing member 10, and the optical fiber sheath 40 is provided with a third channel inside, and the third channel is connected to the first channel. The fastener 50 is movably sleeved outside the optical fiber sheath 40, and is used to fix the temperature measuring component 100. One end of the optical fiber 60 is arranged in the channel of the ceramic ferrule 20 and contacts the fluorescent substance, and the other end extends along the first channel and the third channel, wherein the optical fiber 60 can be an ultraviolet optical fiber for transmitting ultraviolet light and fluorescent signals. It should be noted that the fastener 50 fixes the temperature measuring component, which refers to the fixation of the temperature measuring probe.

[0067] The working principle of the temperature measuring component 100 for the cable joint of the ring network cabinet of the embodiment of the utility model is that the LED in the fluorescent fiber temperature measuring demodulator emits a detection light, which is reflected by the filter in the fluorescent fiber temperature measuring demodulator and then focused by a double convex lens. The end face of the optical fiber 60 (which can be an ultraviolet optical fiber) is placed at the light focusing point of the double convex lens. After the detection light is coupled into the optical fiber 60, the fluorescent material arranged at the other end of the optical fiber 60 is excited. The fluorescent material is stimulated to radiate and generate fluorescence with a wavelength of about a high wavelength. The fluorescence is transmitted through the optical fiber 60 and emitted at the other end of the optical fiber 60. The light focused by the lens is captured by the photodetector in the fluorescent fiber temperature measuring demodulator. The captured light realizes high-precision temperature detection by analyzing the relationship between the characteristics of the fluorescence curve and the temperature.

[0068] The principle of the demodulation optical path is that the radiation-free transition efficiency of the packaging material used in the fluorescent probe is dependent on temperature, and the radiation-free transition efficiency can be expressed as the quenching time. To express it, that is, the temperature can be detected by detecting the fluorescence quenching time, and the fluorescence quenching curve detected by the diode can be fitted as:

[0069]

[0070] in is the fluorescence signal received by the photodetector, is the intensity of the fluorescence signal, For time, is the fluorescence quenching time, is the DC component. Taking a certain moment as the starting point, the curve is integrated three times, and the area S can be expressed as:

[0071]

[0072] make: , the DC component can be removed:

[0073]

[0074] Therefore, the fluorescence quenching time can be expressed as:

[0075]

[0076] This algorithm can efficiently calculate the fluorescence quenching time of the fluorescent substance in the probe and The measured temperature is obtained by fitting a one-dimensional or two-dimensional function relationship with the temperature. This method of testing temperature is more accurate and reliable.

[0077] In the embodiment of the utility model, the temperature measuring probe forms an integral body, and the assembly can be achieved by tightening the movable threaded male head (fastener 50) of the probe with the ceramic tube threaded female head (ceramic sleeve 80) pre-buried in the insulating plug 90. The installation process is simple and convenient, and the probe is not easily damaged. In addition, the movable threaded male head can be movably placed outside the optical fiber sheath 40, and the rotation of the movable threaded male head will not drive the rotation and twisting of the optical fiber sheath 40 and the optical fiber 60. This method will not cause temperature measurement failure or inaccurate temperature measurement due to damage to the optical fiber 60 during the installation of the optical fiber probe, which is beneficial to the accuracy of temperature measurement. In addition, the temperature measuring probe does not include an optical connector, and the optical fiber 60 is a complete whole. There is no pre-buried segmented optical fiber in the insulating plug 90, and there is no need to connect the optical fibers through an optical connector, so no additional insertion loss and return loss will be introduced.

[0078] In an embodiment of the present invention, the material of the optical fiber sheath 40 can be fluorinated ethylene propylene (FEP) or other high temperature resistant materials, and its long-term working temperature is -40-150°C, which can meet the working environment temperature requirements of the cable connector. The optical fiber sheath 40 is connected to the reinforcement 10 through the FEP heat shrink tube 70 to improve the stability of the connection and the high temperature resistance performance.

[0079] In the embodiment of the present utility model, Figure 2 and 3As shown, the inner diameter of the movable threaded male head (fastener 50) is slightly larger than the outer diameter of the optical fiber sheath 40 and slightly smaller than the outer diameter of the reinforcement member 10. Since the movable threaded male head is separated from the optical fiber sheath 40 and the reinforcement member 10 of the temperature measuring probe, it will not drive the optical fiber 60 to rotate and twist during the process of screwing with the ceramic sleeve 80, and thus will not damage the optical fiber 60.

[0080] In some embodiments, the optical fiber channel (first channel) of the reinforcement member 10 can be connected to the optical sensing signal. Figure 2 As shown, the reinforcing member 10 can also be provided with a grinding and fixing groove, and when the end face of the optical fiber 60 is ground, the grinding and fixing groove is used in conjunction with the grinding disk; the channel opened inside the reinforcing member 10 can be inserted with the ceramic ferrule 20 and used to fix the ceramic ferrule 20. And the bottom of the opened channel can be provided with a glue storage for storing excess glue, so as to facilitate the stable connection of the ceramic ferrule 20.

[0081] like Figure 2 As shown, the temperature measuring assembly 100 for the cable joint of the ring main unit further includes a heat shrink tube 70 , which is wrapped around the outer periphery of the optical fiber sheath 40 and the reinforcement member 10 to connect the optical fiber sheath 40 and the reinforcement member 10 .

[0082] refer to Figure 3-Figure 5 The temperature measuring assembly 100 for the cable joint of the ring main unit also includes a ceramic sleeve 80, which is recessed inward from one end to form a receiving cavity 81, and the ceramic end cap 30, the ceramic ferrule 20 and the reinforcement 10 are placed in the receiving cavity 81, and the sealed end of the ceramic end cap 30 contacts the closed end of the ceramic sleeve 80. That is to say, on the one hand, the ceramic sleeve 80 can better protect the temperature measuring probe; on the other hand, the ceramic sleeve 80 can be pre-buried in a set component, such as pre-buried in the insulating plug 90, and the ceramic sleeve 80 can not only play an insulating role, but also has a good thermal conductivity. Then the bottom of the ceramic sleeve 80 is in direct contact with the metal conductor in the insulating plug 90, and the metal conductor can be a metal nut 91 threadedly connected to the cable joint, thereby achieving rapid heat conduction, which can effectively ensure the accuracy of temperature measurement. The metal nut 91 is in the shape of a cap with a threaded hole at one end and a closed end at the other end, and the end with the threaded hole faces the outside of the insulating plug 90.

[0083] Furthermore, the outer surface of the bottom of the ceramic sleeve 80 is in contact with the surface of the metal conductor in the insulating plug 90, and rapid heat conduction is performed through surface contact, so that the temperature of the ceramic sleeve 80 can quickly converge to the temperature of the metal conductor in the insulating plug 90, thereby achieving rapid and accurate temperature detection.

[0084] Furthermore, the ceramic sleeve 80, the ceramic ferrule 20, and the ceramic end cap 30 actually form a heat conduction channel for rapid heat conduction to the fluorescent material in the insulating and heat-insulating main body with the insulating plug 90. On the one hand, the closer the fluorescent material is to the metal conductor in the first direction, the larger the heat conduction channel formed by the ceramic sleeve 80, the ceramic ferrule 20, and the ceramic end cap 30 in conjunction with the metal conductor, the easier it is to make the measured temperature more accurate, and the faster the temperature change feedback speed. However, the thinner the wall of the ceramic sleeve 80 is, the easier it is to be damaged after being subjected to force; therefore, it is necessary to take into account both thermal conductivity and structural reliability, and it is necessary to design it specifically. In some embodiments, the distance between the fluorescent substance and the metal conductor in the first direction is A, 1≤A≤5mm, and at the same time, the end face of the bottom of the ceramic sleeve 80 is a circular plane, and the corresponding end face of the metal conductor in the insulating plug 90 is also a plane. The end face of the bottom of the ceramic sleeve 80 fits the corresponding end face of the metal conductor, and the end face area of ​​the bottom of the ceramic sleeve 80 exceeds 50% of the corresponding end face area of ​​the metal conductor, preferably exceeds 80%, so that surface contact heat conduction can be performed faster and more efficiently. When the above requirements are met at the same time, it can take into account both thermal conductivity and structural reliability.

[0085] In some embodiments, the ceramic sleeve 80 is an alumina ceramic sleeve. Compared with the epoxy resin material of the insulating plug 90, alumina ceramic has great advantages in thermal conductivity and high temperature resistance. Therefore, an alumina ceramic tube is selected as the installation carrier of the temperature probe.

[0086] In some embodiments, the ceramic sleeve 80 may also be a gasket structure, and the present application does not make the sole limitation thereto.

[0087] like Figure 4 As shown, the fastener 50 includes a limiting flange 51 and a threaded rod 52. The threaded rod 52 is connected to the limiting flange 51 to form a T-shape. During installation, the threaded rod 52 can be threadedly connected and fastened with the ceramic sleeve 80. During the fastening process, the fastener 50 can be limited to the port of the ceramic sleeve 80 by the limiting flange 51 to limit the depth of the fastener 50 being screwed in, so that the sealing end of the ceramic end cap 30 just contacts the closed end of the ceramic sleeve 80, which ensures a good thermal conductivity on the one hand and better protects the internal structure of the temperature measuring probe on the other hand. Preferably, the sealing end of the ceramic end cap 30 has an end face that fits the closed end of the ceramic sleeve 80. Compared with point contact, end face contact can better achieve heat transfer and disperse stress to avoid damage caused by stress concentration.

[0088] Furthermore, the portion of the ceramic end cap 30 extending from the reinforcement 10 fits tightly against the inner wall of the ceramic sleeve 80 in the ceramic sleeve 80, thereby maximizing the heat conduction area and further improving the heat conduction efficiency, thereby making temperature monitoring faster and more accurate.

[0089] like Figure 4 As shown, a boss 11 is provided on the outer periphery of the second end of the reinforcement 10 , and when the threaded rod 52 is screwed into the ceramic sleeve 80 , the boss 11 can abut against the bottom of the threaded rod 52 , thereby further limiting the screwing depth of the fastener 50 .

[0090] like Figure 3-Figure 5 As shown, the temperature measuring assembly 100 for the cable joint of the ring main unit also includes an insulating plug 90. The closed end of the ceramic sleeve 80 extends into the interior of the insulating plug 90, and the open end extends out of the outside of the insulating plug 90, and the closed end of the ceramic sleeve 80 abuts against the metal nut 91. The insulating plug 90, the metal nut 91 and the ceramic sleeve 80 are manufactured by a casting process. Among them, 80 is located on the central axis of the metal nut 91. Therefore, after the fastener 50 of the temperature measuring probe is fixed to the ceramic sleeve 80, the temperature measuring probe is fixed, so that the temperature measuring probe can achieve stable contact with the hot spot of the cable joint through the ceramic sleeve 80 and the metal nut 91, which is conducive to ensuring the accuracy of the measured temperature.

[0091] Furthermore, the outer surface of the closed end of the ceramic sleeve 80 has a first plane, and the outer surface of the metal nut 91 has a second plane. The first plane is attached to the second plane, thereby achieving surface contact heat conduction, a large heat conduction area, and fast heat conduction.

[0092] like Figure 5 As shown, a groove 82 that is recessed inward is provided on the outer circumference of the ceramic sleeve 80, and the groove 82 matches the protrusion in the insulating plug 90, and the transverse section is set to be square to prevent the ceramic sleeve 80 from radially moving in the insulating plug 90. The ceramic sleeve 80 and the insulating plug 90 are cast and formed to make the overall connection more secure. Specifically, the groove 82 can be an annular groove surrounding the outer circumference of the ceramic sleeve 80, so that the protrusion in the insulating plug 90 can fill the annular groove and thus prevent the ceramic sleeve 80 from radially moving in the insulating plug 90. Furthermore, the groove 82 can be an open-loop strip groove extending along the circumference of the ceramic sleeve 80, so that the ceramic sleeve 80 can also be limited from rotating in the insulating plug 90.

[0093] Combine the following Figure 1-Figure 5 The embodiment of the present invention illustrates the preparation method of the temperature measuring component 100.

[0094] The preparation method of the temperature measuring component 100 of the embodiment of the utility model mainly includes two parts, one is the insulating material plug (composed of the insulating plug 90, the metal nut 91 and the ceramic sleeve 80), and the other is the temperature measuring probe (including the reinforcement 10, the ceramic ferrule 20, the ceramic end cap 30, the optical fiber sheath 40, the fastener 50 and the optical fiber 60, and the fluorescent substance).

[0095] First, the preparation of the insulating material plug will be described.

[0096] Step 11, prepare the insulating material. Generally, epoxy resin is used because epoxy resin has good chemical resistance, corrosion resistance and electrical insulation. Curing agent is a substance that cures epoxy resin. Commonly used curing agents include amines, acid anhydrides, etc. Fillers can improve the strength, stiffness and wear resistance of epoxy injection molded parts;

[0097] Step 12, model the insulating plug. The mold is made of tool steel because it has good wear resistance and heat resistance. In addition, the mold needs to meet the size design requirements and have a smooth surface without defects.

[0098] Step 13, mixing epoxy resin, curing agent and other raw materials in proportion to obtain epoxy injection molding material;

[0099] Step 14, inject the epoxy injection plastic into the mold that fixes the cable connector and the ceramic sleeve 80, and keep it at a certain temperature and pressure for a certain time, so that the epoxy injection plastic, the metal nut and the ceramic sleeve 80 can be cured and formed. Generally, the higher the curing temperature, the shorter the curing time. Preferably, 100°C, the curing time is 30 minutes, and the pressure is 50psi, which is used to remove the bubbles generated by the epoxy resin during the curing process. Finally, the insulating material plug is obtained. Specifically, the mold includes an upper mold body and a lower mold body that cover each other. The upper mold body is provided with a first assembly cavity of the ceramic sleeve 80, and the ceramic sleeve 80 is assembled in the first assembly cavity; the lower mold body is provided with a second assembly cavity for fixing the metal nut, and the metal nut is assembled in the second assembly cavity; then, the upper mold body and the small mold body are closed together to cooperate with the ceramic sleeve 80 and the metal nut assembled therein to jointly enclose the cavity for forming the insulating body of the insulating plug 90, and then the insulating plug 90, that is, the preparation of the insulating material plug, is completed by the casting process.

[0100] Next, the preparation of the temperature measuring probe is described.

[0101] Step 21, fix the first end of the reinforcement member 10 and the ceramic ferrule 20 with glue, for example, epoxy glue, and connect the optical fiber sheath 40 to the second end of the reinforcement member 10, and the optical fiber sheath 40 can be made of FEP.

[0102] Step 22 , insert the fastener 50 onto the outer circumference of the optical fiber sheath 40 .

[0103] Step 23, insert the optical fiber 60 into the interior of the ceramic ferrule 20, the core diameter of the optical fiber 60 is 200-400 microns, and the high temperature resistant coating layer includes but is not limited to polyimide, PFA, hard plastic, etc.

[0104] Step 24, apply fluorescent material to one end of the ceramic ferrule 20, or add fluorescent material into the ceramic end cap 30, and place the ceramic end cap 30 on the ceramic ferrule 20 and bond it to the inner wall of the first channel of the reinforcement 10, wherein the fluorescent material includes but is not limited to magnesium fluorogermanate, potassium fluorosilicate, barium magnesium silicate, etc.

[0105] Step 25, threading the fastener 50 and the ceramic sleeve 80 (with internal threads) together, thus completing the assembly of the temperature measuring plug. The packaging method is simple. When actually measuring the temperature, firstly thread the insulating plug 90 with the T-shaped cable connector through the metal nut inside it, and then threading the fastener 50 and the ceramic sleeve 80 (with internal threads) together. The temperature measurement is easy to operate.

[0106] In summary, the temperature measuring assembly for the cable joint of the ring network cabinet of the embodiment of the utility model is integrated, and no optical fiber is embedded in the insulating plug 90. The assembly can be achieved by tightening the fastener 50 of the temperature measuring probe with the ceramic sleeve 80 embedded in the insulating plug 90, and the installation process is simple. The fastener 50 is movably sleeved outside the optical fiber sheath 40, that is, the temperature measuring probe is separated, and the optical fiber 60 will not be entangled when it is tightly matched with the ceramic sleeve 80 of the embedded part, thereby avoiding the problems of temperature measurement failure and low accuracy, which is conducive to improving the accuracy of temperature detection. In addition, no optical fiber is embedded in the insulating plug 90, so the temperature measuring assembly for the cable joint of the ring network cabinet does not include an optical connector, and does not require the switching and splicing of two sections of split optical fiber, so no additional insertion loss and return loss will be introduced. The packaging structure of the temperature measurement component for the cable joint of the ring main unit can better protect the optical fiber 60, and use the stimulated radiation of the fluorescent material to generate fluorescence with a wavelength of about a high wavelength. After the fluorescence is transmitted through the optical fiber 60, it is emitted at the other end of the optical fiber 60, and then the light focused by the lens in the fluorescence temperature measurement demodulator is captured by the photoelectric detector. The captured light can achieve high-precision temperature detection by analyzing the relationship between the fluorescence curve characteristics and temperature.

[0107] It can be understood that in the description of the present invention, it is necessary to understand that the terms "upper", "lower", "bottom", "top", "front", "back", "inside", "outside", "horizontal", "vertical", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0108] It can be understood that in the description of the present utility model, it should be noted that, unless otherwise clearly stipulated and limited, the terms "connection", "communication", "connected", "connection" and "fitting" should be understood in a broad sense. For example, it can be a fixed connection, an integral connection, or a detachable connection; it can be the internal communication of two elements; it can be directly connected or indirectly connected through an intermediate medium; "fitting" can be the fit between surfaces, or the fit between points and surfaces or lines and surfaces, and also includes the fit between holes and axes. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0109] The embodiments of the utility model are described above in conjunction with the accompanying drawings, but the utility model is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the utility model, ordinary technicians in this field can also make many forms without departing from the scope of protection of the utility model and the claims, all of which are within the protection of the utility model.

Claims

1. A temperature measuring component for a cable joint of a ring main unit, characterized in that: include: Insulating plug, used to connect with the cable connector; A metal nut, disposed at one end of the insulating plug; A ceramic sleeve, which is disposed at the other end of the insulating plug and faces away from the metal nut, wherein the closed end of the ceramic sleeve extends into the insulating plug, the open end of the ceramic sleeve extends out of the insulating plug, and the closed end of the ceramic sleeve abuts against the metal nut; The temperature measuring probe is threadedly connected to the ceramic sleeve, the temperature measuring probe extends into the ceramic sleeve, and the temperature measuring probe includes an optical fiber and a fluorescent substance arranged at the detection end of the optical fiber, and the detection end of the optical fiber is located in the ceramic sleeve.

2. The temperature measuring assembly for the cable joint of the ring main unit according to claim 1, characterized in that: The temperature measuring probe also includes: A reinforcing member extending in a first direction, the reinforcing member having a first end and a second end opposite to each other in the first direction, and a first channel penetrating the first end and the second end is provided inside the reinforcing member; A ceramic ferrule, one end of which is disposed in the first channel and the other end of which extends out of the first end of the reinforcement member along the first direction, a second channel being disposed inside the ceramic ferrule, and the first channel is connected to the second channel; A ceramic end cap, wherein a chamber with an opening at one end and a sealed chamber at the other end is provided inside the ceramic end cap, wherein the end with the opening is sleeved on the outer periphery of the ceramic insert and fixed in the first channel, and the fluorescent substance is provided in the chamber of the ceramic end cap close to the sealed end; An optical fiber sheath connected to the second end of the reinforcement member, and a third hole is provided inside the optical fiber sheath, and the third hole is communicated with the first hole; A fastener, which is rotatably sleeved outside the optical fiber sheath and is used to fix the temperature measurement component; One end of the optical fiber is arranged in the channel of the ceramic ferrule and contacts the fluorescent substance, and the other end extends along the inside of the first channel and the third channel.

3. The temperature measuring assembly for the cable joint of the ring main unit according to claim 2, characterized in that: Also includes: A heat shrink tube is wrapped around the outer circumference of the optical fiber sheath and the strength member to connect the optical fiber sheath and the strength member.

4. The temperature measuring assembly for the cable joint of the ring main unit according to claim 2, characterized in that: The ceramic sleeve is recessed inward from one end to form a receiving cavity, the ceramic end cap, the ceramic insert and the reinforcement are placed in the receiving cavity, and the sealing end of the ceramic end cap contacts the closed end of the ceramic sleeve.

5. The temperature measuring assembly for the cable joint of the ring main unit according to claim 2, characterized in that: The fastener comprises: A limiting flange, the limiting flange is used to be clamped on the port of the ceramic sleeve; The threaded rod is connected to the limiting flange and is used for being threadedly connected to the side wall of the accommodating cavity of the ceramic sleeve.

6. The temperature measuring assembly for the cable joint of the ring main unit according to claim 5, characterized in that: A boss is provided on the outer periphery of the second end of the reinforcement, and the boss is used to abut against the threaded rod when the threaded rod is screwed into the ceramic sleeve.

7. The temperature measuring assembly for the cable joint of the ring main unit according to claim 6, characterized in that: An inwardly recessed groove is provided on the outer circumference of the ceramic sleeve, and the groove matches the protrusion in the insulating plug.

8. The temperature measuring assembly for the cable joint of the ring main unit according to claim 7, characterized in that: The ceramic bushing and the insulating plug are cast into shape.

9. The temperature measuring assembly for the cable joint of the ring main unit according to claim 1, characterized in that: The insulating plug, the metal nut and the ceramic sleeve are manufactured and formed by a casting process.

10. The temperature measuring assembly for the cable joint of the ring main unit according to claim 1, characterized in that: The outer surface of the closed end of the ceramic sleeve has a first plane, and the outer surface of the metal nut has a second plane, and the first plane is in contact with the second plane.

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