A high-voltage large-current fast fuse

Abstract

A high-voltage and high-current fast fuse comprises an end cover, a contact, a fuse tube, a fuse body, a fuse body guide column, arc extinguishing filler and a fastening screw, characterized in that two or more fuse body guide columns are arranged in the fuse tube, the fuse body is fixed on the fuse body guide column in a spiral winding manner, the contact is provided with a fuse body perforation, the fuse body is welded on the outer end surface of the contact through the perforation, the end cover end surface is overlapped on the outer end of the contact and is connected and fixed with the contact through the fastening screw installed hole of the end cover and the contact and the fastening screw. The disadvantages of poor welding are overcome to the maximum extent. In the case of not increasing the length of the fuse tube or even shortening the length, the rated voltage and the rated current of the fuse can be effectively improved, the anti-impact and anti-bumping capabilities of the fuse are improved, and the fuse can be used to protect the integrated power system of a ship, a large energy storage and power transmission system and other high-voltage and high-current power transmission systems.

Description

Technical fields:

[0001] This utility model relates to a fuse for protecting power lines and power consumption, storage and transmission systems, and in particular to a high-voltage fast-acting fuse. Background Technology

[0002] A fuse is an electrical device that breaks the circuit by melting its own fusible element when the current exceeds a specified value. In use, the fuse is connected in series in the circuit being protected. When an overload or short-circuit current passes through the fusible element, it heats up and melts, thus providing protection for power systems, various electrical equipment, and household appliances. Currently, fuses used to protect shipboard integrated power systems and high-power energy storage systems have complex structures and large sizes due to their high protection voltage requirements. When the rated voltage reaches 5000VDC or higher, their length is generally over 500mm. This not only consumes more materials and increases costs, but also makes transportation, installation, and use inconvenient. Furthermore, because the diameter of the fusible element in the installed circuit is usually less than 0.05mm and the length is over 500mm, it passes directly through the fuse tube without being fixed. During production, transportation, installation, and use, it is easily broken by external forces such as shaking, vibration, impact, collision, and bumps, leading to its scrapping. Some fuses, even if they don't break during production, transportation, and installation, may have their fuse elements stretched thin by external forces. This can cause them to fail to meet the rated technical parameters during use. When the withstand voltage and breaking current have not yet reached the maximum values ​​of the equipment's protection withstand voltage and breaking current, the fuse may break due to the increased temperature at the stretched section, causing the protected equipment to shut down prematurely. This increases the equipment's failure rate, affects its normal operation, and can even cause malfunctions or accidents to other equipment in the system due to premature power loss. When the rated voltage of the required protection system reaches 8000VDC, or even 10kVDC and above, and the rated current reaches 1000A and above, the length of the fuse required for installation will reach 800mm and above. Multiple fuses need to be installed inside the fuse tube. As a result, due to the increased length of the fuses and the need to arrange multiple fuses in the same space, the difficulty of spacing and arranging the fuses will increase. Especially near the middle part, it is difficult to meet the design requirements for the spacing between adjacent fuses. The heat dissipated between fuses with adjacent distances less than the design requirements will be more concentrated than in other parts. This not only affects the service life of the fuse, but also when the system experiences a low overload, the temperature rise at this location may be the first to rise and reach the fusing temperature, causing the fuse to blow prematurely and leading to a power outage accident in the power supply system. Utility Model Content

[0003] To address the above shortcomings, the purpose of this utility model is to provide a high-voltage, high-current fast-acting fuse with a simple, stable, and high-performance structure. The fuse element has been fixed, and without increasing the fuse tube length, or even shortening it, the rated voltage and current carried by the fuse can be effectively increased. Simultaneously, the rated breaking capacity and the breaking speed of fault voltage and current are improved. The fuse element length can reach over 800mm, enabling a rated voltage of 8000VDC, or even 10kVDC. It can be used to protect ship integrated power systems, large-scale energy storage and power transmission systems, as well as other high-voltage, high-current power equipment transmission systems.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] 1. A high-voltage, high-current, fast-acting fuse, comprising an end cap, a contact, a fuse tube, a fusible element, fusible element guide posts, arc-extinguishing filler, and fastening screws, characterized in that: two or more fusible element guide posts are arranged and installed inside the fuse tube; the two ends of the fusible element guide posts are installed in mounting holes provided at the inner end of the contact for installing the fusible element guide posts; the fusible element is arranged and installed on the fusible element guide posts in a spiral winding manner; and the contact has a pre-reserved fusible element through hole for the fusible element to pass through, so that the two ends of the fusible element are welded to the outer end face of the contact.

[0006] The end cap is pressed onto the outer end of the contact and is connected and fixed to the contact through the fastening screw mounting holes provided on the end cap and the contact with fastening screws. The outer edge is inserted into the molten tube in an interference fit. The arc-extinguishing filler is filled into the inside of the molten tube through the filling holes provided on the contact and the end cap, so that the space outside the molten guide post wrapped with molten material is completely filled and covered by the arc-extinguishing filler.

[0007] 2. The melt guide post is provided with a spiral groove, and the melt is wound in the groove of the melt guide post. Its protruding part can play the role of blocking the arc jet.

[0008] 3. The melt wound on the melt guide post is coated with an arc-quenching adhesive to fix the melt between the melt guide post and the surface of the melt, so that the surface of the melt does not come into direct contact with the arc-quenching filler filled inside the melt tube, thereby isolating the melt from contact with the residual air between the melt and the filled arc-quenching filler particles, preventing the melt from oxidizing, and at the same time, this arc-quenching adhesive can increase the arc-quenching effect.

[0009] 4. Depending on the required current, two or more melt strands are wound around each melt guide post.

[0010] 5. The number of molten metal perforations provided on the contact is multiple, and the shapes include square, polygonal, circular, and rounded rectangle.

[0011] 6. The melt wound on the melt guide post is a variable cross section, including a fixed side, a narrow diameter and a forming part. The narrow diameter is composed of a number of holes arranged in a spaced manner along the length of the melt.

[0012] This invention incorporates two or more fusible guide posts within the fuse tube. The fusible material is wound around grooves on these guide posts, passing through fusible material perforations on the contacts at both ends, and welded to the outer end face of the contacts. An end cap is then pressed onto the outer end face of the contacts and securely connected to them with fastening screws. The outer edge of the end cap is also press-fitted onto the fuse tube. This design not only integrates the contacts, end cap, fusible material, and fuse tube into a single unit, but also ensures sufficient contact between the fusible material and contacts because the fusible material is welded to the outer end face of the contacts, and the end cap is pressed onto it and secured with fastening screws. This effectively overcomes the potential for incomplete welds and weak welds that may occur during the welding of the fusible material and contacts. This method addresses defects such as incomplete welding and failure to meet design requirements, minimizing contact resistance between the two components. Furthermore, since the connecting edge of the molten element is welded to the outer end face of the contact, this method not only facilitates welding operations and significantly increases the welding speed but also allows for quick and direct inspection of weld quality. Additionally, applying arc-quenching adhesive between the molten element guide post and the molten element, as well as to the molten element surface, ensures the molten element is firmly fixed to the guide post, providing excellent resistance to external forces. Even during production, transportation, installation, and use, subjected to shaking, vibration, impact, collision, and bumps, the molten element will not break or become thinner due to stress, greatly improving the stability of the fuse. Simultaneously, it prevents the molten element surface from directly contacting the arc-quenching filler inside the molten tube, preventing or isolating residual air between the molten element and the arc-quenching filler particles, preventing molten element oxidation, and extending the fuse's service life.

[0013] Because the fusible element is spirally wound around the fusible element guide post inside the fuse tube, the length of the fusible element that can be installed is greatly increased without increasing or even shortening the overall length of the fuse. This allows the rated voltage that can be carried to be multiplied. Furthermore, the setting of two or more fusible element guide posts, and the fact that two or more fusible elements can be wound on each fusible element guide post according to the required rated current, allows multiple fusible elements to be installed and arranged inside the fuse tube at the same time. The larger the current, the more fusible elements are required.

[0014] In this invention, the grooves on the melt guide post that rotate along the spiral naturally form protrusions corresponding to the grooves, which can block the arc jet.

[0015] Because the inner cavity of the fusion tube is filled with an arc-extinguishing medium, this invention not only extinguishes the arc quickly when the molten metal melts, but also has good heat dissipation under long-term load current.

[0016] The fusible element of this invention has a variable cross-section, including a fixed side, a narrow diameter, and a forming part. The narrow diameter is composed of several holes arranged evenly along the length of the fusible element at intervals. When an overload occurs in the system protected by the fuse, the current resistance through the narrow diameter is greater than that through other parts because the cross-section of the narrow diameter is narrower than that of other parts. This causes the narrow diameter to heat up first and reach the melting temperature first, thus preventing the fuse from blowing and causing a long arc, which could lead to an explosion or fire. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the internal cross-sectional structure of an embodiment of the present utility model.

[0018] Figure 2 This is an exploded view of the components of an embodiment of this utility model.

[0019] Figure 3 This is a schematic diagram of the contact shape structure of an embodiment of the present utility model.

[0020] Figure 4 This is a schematic diagram of the structure of the contact inner end face with melt guide post installed in an embodiment of the present invention.

[0021] Figure 5 This is a schematic diagram of the structure in which the outer end face of the contact is welded with molten material according to an embodiment of the present invention.

[0022] Figure 6 This is a schematic diagram of the melt structure of an embodiment of the present invention.

[0023] Explanation of reference numerals in the attached drawings: 1. End cap; 2. Contact; 3. Melt; 4. Melt tube; 5. Melt guide post; 6. Arc extinguishing filler; 7. Fastening screw; 11. Fastening screw hole; 21. Melt guide post mounting hole; 22. Melt hole; 23. Fastening screw hole; 31. Connecting edge; 32. Narrow diameter; 33. Forming part. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings.

[0025] Example: A high-voltage, high-current, fast-acting fuse, such as... Figure 1 , 2As shown in Figures 1, 3, 4, and 5, this embodiment illustrates a fuse equipped with four fusible guide posts. The components include: end cap 1, contact 2, fusible element 3, fusible tube 4, fusible guide post 5, arc-extinguishing filler 6, fastening screw 7, and arc-extinguishing medium filling hole (not shown in the figure). As shown in Figures 1, 3, 4, and 5, four mounting holes 22 for the fusible guide posts 5 are evenly spaced on the inner end face of the contact 2. Adhesive (not shown in the figure) is pre-applied to the mounting holes before the fusible guide posts 5 are installed. The fusible guide posts 5 are inserted into the mounting holes 22. The fusible element 3 is spirally wound into the mounting grooves on the fusible guide posts 5. The connecting edges 31 at both ends of the fusible element 3 pass through the fusible through-holes 21 on the contact 2 and are welded to the outer end face of the contact 2. This welding method is not only convenient to operate and fast, but also allows for easy inspection of welding quality, preventing or reducing the occurrence of incomplete welds.

[0026] The device is equipped with a melt guide post 5, on which melt 3 is wound. The connecting edges of the melt 3 at both ends have passed through the melt through holes 21 on the contact 2 and are welded to the outer end face of the contact 2. The melt core composed of these parts passes through the melt tube 4 and is fitted inside the melt tube 4. End caps 1 are fitted at both ends and are connected and fixed by fastening screws 7 through the fastening screw through holes 11 on the end caps 1 and the fastening screw through holes 23 on the contact 2. The outer edge of the end caps 1 is fitted onto the melt tube 4 in an interference fit, so that the melt core and the melt tube 4 are connected and fixed as a whole, which can effectively prevent the melt core from moving.

[0027] The arc-extinguishing filler 6 is filled into the inner cavity of the molten tube 4 through the filling holes (not shown in the figure) provided on the end cap 1 and the contact 2. The inner cavity of the molten tube 4 is completely filled, so that the core of the molten core of the four molten guide pillars 5 with molten 3 arranged and installed inside the molten tube 4 is completely filled and covered by the filled arc-extinguishing filler 6. While extinguishing the arc when the molten 3 melts, it can also have a good heat dissipation function under long-term load current.

[0028] The surface of the melt 3 is coated with a sealing arc-extinguishing adhesive (not shown in the figure), which prevents the surface of the melt 3 from directly contacting the arc-extinguishing filler 6 that is filled and covered in the melt tube 4. This isolates the melt from contact with residual air between the melt and the arc-extinguishing filler particles, prevents the melt from oxidizing, and extends the service life of the fuse.

[0029] like Figure 2 , 4As shown in Figure 5, since the fusible element 3 is spirally wound on the fusible element conductor 5 inside the fuse tube 4, the rated voltage that the fuse can carry can be greatly increased, even by several times, without increasing the overall length of the fuse. Furthermore, since there are 4 fusible element conductors 5 arranged inside the fuse tube 4, and more can be added as needed, even up to 7, 8 or more, and the number of fusible elements 3 wound on each fusible element conductor 5 can also be increased to 3, 4 or more, the rated current that the fuse can carry can also be increased exponentially. This completely overcomes the drawback that current electrical protection systems that need to carry high currents are composed of multiple fuses connected in parallel, which can facilitate installation and reduce manufacturing and maintenance costs.

Claims

1. A high-voltage, high-current, fast-acting fuse, comprising an end cap, contacts, a fuse tube, a fuse element, a fuse element guide post, arc-extinguishing filler, and a fastening screw, characterized in that: The melt tube is equipped with two or more melt guide posts. The two ends of the melt guide posts are installed in the mounting holes provided at the inner end of the contact for installing the melt guide posts. The melt is arranged and installed on the melt guide posts in a spiral winding manner. The contact has a melt through hole for the melt to pass through, so that the two ends of the melt are welded to the outer end face of the contact. The end cap is pressed onto the outer end of the contact and is connected and fixed to the contact through the fastening screw mounting holes provided on the end cap and the contact with fastening screws. The outer edge is inserted into the molten tube in an interference fit. The arc-extinguishing filler is filled into the inside of the molten tube through the filling holes provided on the contact and the end cap, so that the space outside the molten guide post wrapped with molten material is completely filled and covered by the arc-extinguishing filler.

2. The high-voltage, high-current, fast-acting fuse according to claim 1, characterized in that: The melt guide post is provided with a spiral groove, and the melt is wound around the groove of the melt guide post. Its protruding part can play the role of blocking the arc jet.

3. A high-voltage, high-current, fast-acting fuse according to claim 1, characterized in that: The melt wound around the melt guide post is coated with an arc-quenching adhesive to fix the melt between the melt guide post and the surface of the melt, so that the surface of the melt does not come into direct contact with the arc-quenching filler filled inside the melt tube. This isolates the melt from contact with residual air between the melt and the filled arc-quenching filler particles, preventing the melt from oxidizing. At the same time, this arc-quenching adhesive can increase the arc-quenching effect.

4. A high-voltage, high-current, fast-acting fuse according to claim 1, characterized in that: There are two or more melt strands wound around each melt guide post.

5. A high-voltage, high-current, fast-acting fuse according to claim 1, characterized in that: The contact is provided with multiple melt perforations, and the shapes include polygons and circles.

6. A high-voltage, high-current, fast-acting fuse according to claim 1, characterized in that: The melt wound around the melt guide post has a variable cross section, including a fixed side, a narrow diameter, and a forming part. The narrow diameter is composed of several holes arranged in a spaced manner along the length of the melt.

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