Novel bushing type insulator for explosion-proof cabinet

Abstract

The invention relates to the technical field of electrical accessories, and discloses a novel bushing type insulator for an explosion-proof cabinet, which comprises a connecting plate, an embedding block is fixedly connected to the center of the front side of the connecting plate, a conical bushing is fixedly connected to the front end of the embedding block, and a connecting sleeve is fixedly connected to the rear side of the connecting plate. Uniformly distributed umbrella skirts are fixedly connected to the outer surface of the connecting sleeve, a placement cavity is formed in the inner diameter of the connecting sleeve, a sensor is mounted at the top of the embedding block, and the conical sleeve, the embedding block, the connecting plate and the placement cavity are communicated with one another. Through an APG epoxy resin pouring process, integral forming and effective wrapping of an electrified body, and through the mode design of an all-insulation shielding type European-style plug, an electrified part is further completely isolated, underground moisture and dust accumulation risks are greatly reduced, the insulation performance of the whole cabinet is improved, weather resistance is enhanced, long-term stable operation in a severe mine environment is ensured, and the service life of the cabinet is prolonged. And electrical potential safety hazards are greatly reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical accessories, and more specifically, to a novel bushing insulator for explosion-proof cabinets. Background Art

[0002] Insulators are key components in the power system used to support and fix conductors, and keep the conductors insulated from other components or the ground. Its core function is to ensure that electric current only flows in a predetermined path, preventing electric leakage, short circuits or electric shock accidents. At the same time, it bears mechanical loads and environmental impacts. Insulators need to have high insulation performance, good mechanical strength, and resistance to aging, pollution, etc. They are widely used in transmission lines, substations, and explosion-proof cabinets, and are important basic components to ensure the safe and stable operation of the power system.

[0003] Currently, when the existing insulators are in use, after the copper busbar is lapped with the insulator and connected to the bus, insulation treatment needs to be carried out. The live parts cannot be completely isolated and are exposed to the air. There will be great potential safety hazards due to the accumulation of moisture and dust on the surface during long-term operation in the mine. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the present invention provides a novel bushing insulator for explosion-proof cabinets, which solves the problems that after the copper busbar is lapped with the insulator and connected to the bus, the live parts cannot be completely isolated, are exposed to the air, and there are great potential safety hazards.

[0005] To achieve the above objectives, the present invention is realized through the following technical solutions: A novel bushing insulator for explosion-proof cabinets includes a connection plate. At the central position on the front side of the connection plate, a fitting block is fixedly connected. At the front end of the fitting block, a conical bushing is fixedly connected. At the rear side of the connection plate, a connection sleeve is fixedly connected. On the outer surface of the connection sleeve, uniformly distributed umbrella skirts are fixedly connected. Inside the inner diameter of the connection sleeve, a placement cavity is provided. A sensor is installed on the top of the fitting block. The conical bushing, the fitting block, the connection plate, and the placement cavity communicate with each other. Inside the inner diameter of the conical bushing, a conductive copper bar is provided. At the front end of the conductive copper bar, a first connection groove is provided. At the rear end of the conductive copper bar, a second connection groove is provided.

[0006] Preferably, the conductive copper bar includes a cylindrical conductive copper bar. At the front end of the cylindrical conductive copper bar, a first connection groove is provided. At the rear end of the cylindrical conductive copper bar, a second connection groove is provided.

[0007] Preferably, the conductive copper bar includes a corner conductive copper bar. At the front end of the corner conductive copper bar, a first connection groove is provided. At the rear end of the corner conductive copper bar, a second connection groove is provided.

[0008] Preferably, the sensor surrounds the outside of the conductive component.

[0009] Preferably, four connection holes are provided on the surface of the connection plate.

[0010] Preferably, the inner walls of the first connection groove and the second connection groove are both provided with internal threads for threaded connection with external conductive components.

[0011] Preferably, the tapered sleeve, the fitting block, the connecting plate, the connecting sleeve and the petticoat are integrally formed by the APG epoxy resin casting process.

[0012] Preferably, the sensor is a current sensor or a voltage sensor, and the sensor is electrically connected to the live indicator for real-time detection of current or voltage signals in the conductive component and intuitive display of the live state of the cable through the live indicator.

[0013] A preparation method for a new type of bushing insulator for an explosion-proof cabinet includes the following steps: Step 1, design a split combination mold according to the integrated structure of the tapered sleeve, the fitting block, the connecting plate, the connecting sleeve and the petticoat; Step 2, embed a cylindrical conductive copper bar or a corner conductive copper bar into the tapered sleeve and make a threaded fastening connection; Step 3, install the current / voltage sensor around the outer wall of the conductive copper bar and connect it to the live indicator circuit; Step 4, preheat the mold to 60 - 80 °C, inject epoxy resin under a pressure of 0.3 - 0.5 MPa by the automatic pressure gel process, control the curing temperature at 120 - 140 °C, and keep warm for 2 - 4 hours to form an insulating body; Step 5, remove the casting burrs and perform a silicone rubber coating treatment on the surface of the petticoat; Step 6, apply an air pressure of 0.8 - 1.2 MPa to the placement cavity and keep the pressure for 30 minutes without leakage.

[0014] Preferably, in Step 2, the epoxy resin mixed filler is 25 - 35 wt% of nano-silica and 5 - 10 wt% of silicon carbide particles, and the pressure is applied in stages during the casting process: 0.2 - 0.3 MPa is maintained for 5 - 8 minutes in the initial stage, and the pressure is increased to 0.4 - 0.5 MPa in the second stage and kept until the curing is completed; After Step 6 is completed, perform a partial discharge test on the overall insulator, apply an 8 - 10 kV AC voltage, and the partial discharge amount ≤ 5 pC.

[0015] Working principle: In a mine-use high-voltage explosion-proof cabinet of 10 kV and below, it is fixed to the explosion-proof cabinet through four connection holes on the surface of the connecting plate to achieve a firm connection with the cabinet body; A cylindrical conductive copper bar or a corner conductive copper bar is placed inside the inner diameter of the tapered sleeve. With the help of the first connection groove at the front end and the second connection groove at the rear end, it is threadedly connected to the external conductive component through the internal thread to achieve the electrical connection of the incoming cable and the busbar between each cabinet; The conical bushing, fitting block, connecting plate, connecting sleeve and petticoat are integrally formed by the APG epoxy resin casting process. Coupled with the use of the design mode of a fully insulated shielded European plug, the live parts are isolated in all directions, resisting the erosion of underground moisture and dust, significantly improving the insulation performance and weather resistance of the whole cabinet, and ensuring reliable operation in harsh mine environments; At the same time, the current or voltage sensor at the top of the fitting block surrounds the conductive copper bar, real-time senses the current or voltage signal in the conductive component, and transmits it to the live indicator, visually presenting the live state of the cable. This enables the staff to clearly know the live condition of the equipment when maintaining the equipment, preventing safety accidents caused by uninspected power.

[0016] The present invention provides a novel bushing insulator for explosion-proof cabinets. It has the following beneficial effects: 1. Through the APG epoxy resin casting process, the present invention integrally forms the conical bushing, fitting block, connecting plate, connecting sleeve and petticoat components, effectively wrapping the live body, completely covering all the exposed live parts of the insulator, and using the design mode of a fully insulated shielded European plug to further completely isolate the live parts, greatly reducing the risk of underground moisture and dust accumulation, improving the insulation performance of the whole cabinet, enhancing the weather resistance, ensuring long-term stable operation in harsh mine environments, and significantly reducing electrical safety hazards.

[0017] 2. Through the conical connecting bushing of the present invention, in combination with a cylindrical or corner conductive copper bar and a connecting groove with internal threads, the incoming and outgoing cables and the busbars between cabinets can be quickly connected with a special European plug, improving the connection efficiency, meeting different wiring requirements, and the connection is firm and reliable, without the need for complex insulation treatment, bringing a new experience of high efficiency and convenience to the electrical connection of mine-used high-voltage explosion-proof cabinets.

[0018] 3. By adding a current or voltage sensor in the bushing insulator of the present invention and connecting it to the live indicator, the live state of the cable is monitored in real time, avoiding safety accidents caused by uninspected power during maintenance. At the same time, the concentric and eccentric structural forms ingeniously increase the distance between the three-phase busbars, effectively saving the design space, taking into account both safety and space utilization, and improving the overall performance of the mine-used high-voltage explosion-proof cabinet. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a three-dimensional view of the concentric insulator of the novel bushing insulator for explosion-proof cabinets of the present invention; Figure 2 is a rear view schematic diagram of the concentric insulator of the novel bushing insulator for explosion-proof cabinets of the present invention; Figure 3 is a cross-sectional schematic diagram of the concentric insulator of the novel bushing insulator for explosion-proof cabinets of the present invention; Figure 4 is a three-dimensional view of the eccentric insulator of the novel bushing insulator for explosion-proof cabinets of the present invention; Figure 5 Rear view schematic diagram of the eccentric insulator of the novel bushing insulator for explosion-proof cabinets of the present invention; Figure 6 Cross-sectional schematic diagram of the eccentric insulator of the novel bushing insulator for explosion-proof cabinets of the present invention; Figure 7 Flow schematic diagram of the preparation method of the novel bushing insulator for explosion-proof cabinets of the present invention.

[0020] Among them, 1. Conical bushing; 2. Fitting block; 3. Connection plate; 4. Connection sleeve; 5. Umbrella skirt; 6. First connection groove; 7. Connection hole; 8. Second connection groove; 9. Cylindrical conductive copper bar; 10. Sensor; 11. Placement cavity; 12. Corner conductive copper bar. Specific embodiments

[0021] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the drawings of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0022] Embodiment 1: Concentric insulator Please refer to the appendix Figure 1 - appendix Figure 3 , the embodiment of the present invention provides a novel bushing insulator for explosion-proof cabinets, including a connection plate 3. A fitting block 2 is fixedly connected to the center position on the front side of the connection plate 3. A conical bushing 1 is fixedly connected to the front end of the fitting block 2. A connection sleeve 4 is fixedly connected to the rear side of the connection plate 3. Uniformly distributed umbrella skirts 5 are fixedly connected to the outer surface of the connection sleeve 4. A placement cavity 11 is provided in the inner diameter of the connection sleeve 4. A sensor 10 is installed on the top of the fitting block 2. The conical bushing 1, the fitting block 2, the connection plate 3 and the placement cavity 11 communicate with each other. A conductive copper bar is provided inside the conical bushing 1. A first connection groove 6 is provided at the front end of the conductive copper bar, and a second connection groove 8 is provided at the rear end of the conductive copper bar.

[0023] The connection plate 3 is used to fix the insulator to the explosion-proof cabinet; the fitting block 2 connects the conical bushing 1 and the connection plate 1; the conical bushing 1 is inserted into the corresponding space to achieve a specific connection function; the umbrella skirts 5 increase the creepage distance and enhance insulation; the placement cavity 11 can accommodate some components; the mutually communicating structure facilitates the penetration of the conductive copper bar; the first connection groove 6 and the second connection groove 8 are used to connect external conductive components, thus constructing a complete and compact insulator structure to ensure electrical connection and insulation performance.

[0024] The conductive copper bar includes a cylindrical conductive copper bar 9. A first connection groove 6 is provided at the front end of the cylindrical conductive copper bar 9, and a second connection groove 8 is provided at the rear end of the cylindrical conductive copper bar 9.

[0025] The cylindrical conductive copper bar 9 with a cylindrical shape regularizes the current transmission path, reduces resistance loss. The first connection groove 6 and the second connection groove 8 at both ends facilitate connection with other components, and provide a good conductive path when a straight connection of an incoming cable or busbar is required.

[0026] The sensor 10 surrounds the outside of the conductive component.

[0027] According to the principle of electromagnetic induction, changes in the electromagnetic field around the conductive copper bar will generate corresponding signals in the sensor. The surrounding installation enables the sensor 10 to monitor the changes in the electromagnetic field around the conductive copper bar in all directions, obtain current or voltage information, and can more accurately and comprehensively sense the electrical signals of the conductive component.

[0028] Four connection holes 7 are provided on the surface of the connection plate 3.

[0029] Using the principle of mechanical fastening, the insulator is fixed to the explosion-proof cabinet by bolts passing through the connection holes 7. The four connection holes 7 provide multiple fixing points, ensuring the stability of the insulator installation and facilitating the firm installation of the insulator on the explosion-proof cabinet using connection parts such as bolts.

[0030] Internal threads are provided on the inner walls of the first connection groove 6 and the second connection groove 8 for threaded connection with external conductive components.

[0031] Threaded connection makes two components closely combined through frictional force and spiral force, reduces contact resistance. The internal thread cooperates with the external thread of the external conductive component, ensuring reliable electrical connection after tightening, and realizing rapid and stable connection between the conductive copper bar and the external conductive component.

[0032] The conical sleeve 1, the fitting block 2, the connection plate 3, the connection sleeve 4 and the petticoat 5 are integrally formed by the APG epoxy resin casting process.

[0033] The APG epoxy resin casting process fills the epoxy resin into the mold and cures it at a certain temperature and pressure. The integral forming reduces the gaps between components, enhances the insulation performance and mechanical strength, improves the overall stability and durability, and forms a high-strength, high-insulation-performance and well-sealed overall structure.

[0034] The sensor 10 is a current sensor or a voltage sensor. The sensor 10 is electrically connected to the live indicator, and is used to detect the current or voltage signal in the conductive component in real time, and visually display the live state of the cable through the live indicator.

[0035] The sensor 10 senses the electrical signal and transmits it to the live indicator. The live indicator processes the signal through the circuit and then displays it. The sensor 10 monitors the current or voltage signal in real time, and the live indicator converts the signal into a visual display, enabling the operator to intuitively and timely understand the live state of the cable and ensuring operation safety.

[0036] Preparation method of a new type of bushing insulator for explosion-proof cabinets, comprising the following steps: Step 1, design a split combined mold according to the integrated structure of the conical bushing 1, the fitting block 2, the connecting plate 3, the connecting sleeve 4 and the umbrella skirt 5; Step 2, embed the cylindrical conductive copper rod 9 into the conical bushing 1 and connect it tightly by threads; Step 3, install the current / voltage sensor 10 around the outer wall of the conductive copper rod and connect it to the live indicator line; Step 4, preheat the mold to 60 - 80 °C, inject epoxy resin under a pressure of 0.3 - 0.5 MPa using the automatic pressure gel process, control the curing temperature at 120 - 140 °C, and keep warm for 2 - 4 hours to form the insulation body; Step 5, remove the casting burrs and perform a silicone rubber coating treatment on the surface of the umbrella skirt 5; Step 6, apply an air pressure of 0.8 - 1.2 MPa to the placement cavity 11 and keep the pressure for 30 minutes without leakage.

[0037] In Step 2, the epoxy resin mixed filler is 25 - 35 wt% of nano-silica and 5 - 10 wt% of silicon carbide particles, and segmented pressure is applied during the casting process: 0.2 - 0.3 MPa is maintained for 5 - 8 minutes in the initial stage, and it is increased to 0.4 - 0.5 MPa in the second stage and kept until the curing ends; After Step 6 is completed, perform a partial discharge test on the overall insulator, apply an 8 - 10 kV AC voltage, and the partial discharge amount ≤ 5 pC.

[0038] Example 2: Eccentric insulator Please refer to the attached Figure 4 - attached Figure 6 , the conductive copper rod includes a corner conductive copper rod 12, a first connection groove 6 is opened at the front end of the corner conductive copper rod 12, and a second connection groove 8 is opened at the rear end of the corner conductive copper rod 12.

[0039] The corner conductive copper rod 12 changes the current transmission direction through a corner design. At the same time, the first connection groove 6 and the second connection groove 8 ensure firm connection. In the case of complex wiring in the explosion-proof cabinet, connections of lines with different directions are realized. The corner conductive copper rod 12 meets the electrical connection requirements for changing directions in wiring and increases connection flexibility.

[0040] Please refer to the attached Figure 7 , preparation method of a new type of bushing insulator for explosion-proof cabinets, comprising the following steps: Step 1, design a split combined mold according to the integrated structure of the conical bushing 1, the fitting block 2, the connecting plate 3, the connecting sleeve 4 and the umbrella skirt 5; Design a split mold according to the complex shape of the insulator. After splicing each part, a complete cavity is formed. The split-type combined mold is convenient for installing the conductive copper bar and the sensor 10, and is conducive to demolding, providing an accurate mold for the subsequent molding process, and ensuring the dimensional accuracy of each component of the insulator and the overall structure.

[0041] Step 2: Insert the corner conductive copper bar 12 into the conical sleeve 1 and connect them tightly by thread fastening. Utilize the spiral force and friction force of the thread to achieve fastening. The thread fastening connection makes the conductive copper bar and the conical sleeve 1 closely combined, preventing loosening from affecting the conductivity, ensuring the fixed position of the conductive copper bar in the insulator, and guaranteeing the reliability of the electrical connection.

[0042] Step 3: Install the current / voltage sensor 10 around the outer wall of the conductive copper bar and connect it to the live indicator circuit. According to the working principle of the sensor 10, obtain the electromagnetic signal by surrounding the conductive copper bar and transmit it through the circuit, so that the sensor 10 can accurately monitor the electrical signal of the conductive copper bar and transmit it to the live indicator.

[0043] Step 4: Preheat the mold to 60 - 80 °C, inject epoxy resin under a pressure of 0.3 - 0.5 MPa using the automatic pressure gel process, control the curing temperature at 120 - 140 °C, and keep warm for 2 - 4 hours to form the insulation body. Preheat the mold, control the pressure and temperature, and keep warm for a certain time, so that the epoxy resin fully reacts and cures, obtaining ideal insulation performance and mechanical strength. Then, make the epoxy resin cure under suitable conditions to form an insulation body with good performance.

[0044] Step 5: Remove the casting burrs and perform silicone rubber coating treatment on the surface of the umbrella skirt 5. The silicone rubber material has good insulation and weather resistance characteristics. Removing the burrs can avoid local electric field concentration. The silicone rubber coating enhances the insulation, waterproof and anti-aging capabilities of the umbrella skirt, improving the appearance quality of the insulator and the insulation and weather resistance performance of the umbrella skirt 5.

[0045] Step 6: Apply an air pressure of 0.8 - 1.2 MPa to the placement cavity 11 and keep the pressure for 30 minutes without leakage.

[0046] Under a pressure higher than the normal ambient pressure, if there is a leak, the air pressure will drop. The pressure holding test is used to check whether there is a leak point, ensuring the stability of the internal environment of the insulator, detecting the sealing performance of the placement cavity, and ensuring that the internal components are not affected by the external environment.

[0047] In Step 2, the epoxy resin mixed filler is 25 - 35 wt% of nano-silica and 5 - 10 wt% of silicon carbide particles. During the pouring process, pressurize in sections: maintain at 0.2 - 0.3 MPa for 5 - 8 minutes in the initial stage, and increase to 0.4 - 0.5 MPa in the second stage and keep it until the curing ends. After Step Six, conduct a partial discharge test on the entire insulator, apply an AC voltage of 8 - 10 kV, and the partial discharge amount ≤ 5 pC.

[0048] Nano-silica and silicon carbide particles fill the epoxy resin gaps, changing its physical properties; segmented pressurization is conducive to the uniform dispersion of the fillers. Nano-silica enhances the mechanical strength and insulation performance, and silicon carbide particles improve the thermal conductivity; segmented pressurization makes the filler distribution more uniform, improving the mechanical strength, thermal conductivity, and insulation performance of the insulation body. Under a certain voltage, detect whether there is a partial discharge phenomenon inside the insulator and the magnitude of the discharge amount. Screen out the products with qualified partial discharge amounts through testing, avoid insulation aging caused by partial discharge, ensure the reliability of the insulator during operation at high voltages, and reduce the risk of partial discharge.

[0049] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A novel sleeve insulator for an explosion-proof cabinet, comprising a connecting plate (3), characterized in that: A fitting block (2) is fixedly connected to the center position on the front side of the connecting plate (3). A conical sleeve (1) is fixedly connected to the front end of the fitting block (2). A connecting sleeve (4) is fixedly connected to the rear side of the connecting plate (3). Uniformly distributed umbrella skirts (5) are fixedly connected to the outer surface of the connecting sleeve (4). A placement cavity (11) is formed in the inner diameter of the connecting sleeve (4). A sensor (10) is installed on the top of the fitting block (2). The conical sleeve (1), the fitting block (2), the connecting plate (3) and the placement cavity (11) are mutually communicated. A conductive copper bar is arranged inside the conical sleeve (1). A first connection groove (6) is formed at the front end of the conductive copper bar. A second connection groove (8) is formed at the rear end of the conductive copper bar.

2. The novel bushing insulator for an explosion-proof cabinet according to claim 1, wherein: The conductive copper bar includes a cylindrical conductive copper bar (9). A first connection groove (6) is formed at the front end of the cylindrical conductive copper bar (9). A second connection groove (8) is formed at the rear end of the cylindrical conductive copper bar (9).

3. The novel bushing insulator for an explosion-proof cabinet according to claim 1, characterized in that: The conductive copper bar includes a corner conductive copper bar (12). A first connection groove (6) is formed at the front end of the corner conductive copper bar (12). A second connection groove (8) is formed at the rear end of the corner conductive copper bar (12).

4. The novel bushing insulator for an explosion-proof cabinet according to claim 1, wherein: The sensor (10) surrounds the outside of the conductive component.

5. The novel bushing insulator for an explosion-proof cabinet according to claim 1, characterized in that: Four connection holes (7) are formed on the surface of the connecting plate (3).

6. The novel sleeve-type insulator for an explosion-proof cabinet according to claim 1, wherein: Internal threads are arranged on the inner walls of the first connection groove (6) and the second connection groove (8) for threaded connection with external conductive components.

7. The novel sleeve insulator for an explosion-proof cabinet according to claim 1, wherein: The conical sleeve (1), the fitting block (2), the connecting plate (3), the connecting sleeve (4) and the umbrella skirts (5) are integrally formed by the APG epoxy resin casting process.

8. The novel bushing insulator for explosion-proof cabinets according to claim 1, characterized in that: The sensor (10) is a current sensor or a voltage sensor. The sensor (10) is electrically connected to a live indicator for real-time detection of current or voltage signals in the conductive component and intuitive display of the live state of the cable through the live indicator.

9. Preparation method of a novel bushing insulator for an explosion-proof cabinet, characterized in that, For the novel sleeve-type insulator for an explosion-proof cabinet according to any one of claims 1-8, the following steps are included: Step 1, design a split-type combined mold according to the integrated structure of the conical sleeve (1), the fitting block (2), the connecting plate (3), the connecting sleeve (4) and the umbrella skirts (5); Step 2, embed the cylindrical conductive copper bar (9) or the corner conductive copper bar (12) into the conical sleeve (1) and fasten it by threaded connection; Step 3, install the current / voltage sensor (10) around the outer wall of the conductive copper bar and connect it to the circuit of the live indicator; Step 4, preheat the mold to 60-80 °C, inject epoxy resin under a pressure of 0.3-0.5 MPa by the automatic pressure gel process, control the curing temperature at 120-140 °C, and keep warm for 2-4 hours to form an insulating body; Step 5, remove the casting burrs and perform silicone rubber coating treatment on the surface of the umbrella skirts (5); Step 6, apply a gas pressure of 0.8-1.2 MPa to the placement cavity (11) and keep the pressure for 30 minutes without leakage.

10. The preparation method of the novel bushing insulator for the explosion-proof cabinet according to claim 9, characterized in that: In the second step, the epoxy resin mixed with fillers is composed of 25-35 wt% of nano-silica and 5-10 wt% of silicon carbide particles. During the casting process, pressure is applied in stages: at the initial stage, 0.2-0.3 MPa is maintained for 5-8 minutes, and in the second stage, it is increased to 0.4-0.5 MPa and maintained until curing is completed; After the sixth step is completed, a partial discharge test is carried out on the overall insulator. An AC voltage of 8-10 kV is applied, and the partial discharge amount ≤ 5 pC.

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