Drop-out fuse with length-adjustable fuse tube

Abstract

The invention relates to the technical field of electric power facilities, in particular to a drop-out fuse with a length-adjustable fuse tube. The fuse comprises a fuse tube and a fuse, the two ends of the fuse tube are connected with an upper sleeve and a lower sleeve respectively, the lower sleeve comprises a lower static contact, two lower moving contacts and an elastic piece, the fuse tube is sleeved with the lower static contact, and the lower static contact and the lower moving contact are fastened through a screw; the middle part of the elastic sheet is connected with the two lower moving contacts through an elastic sheet hinging rod, the two lower moving contacts are connected through a connecting plate, the elastic sheet hinging rod is sleeved with a torsional spring, one end of the torsional spring is in contact with the connecting plate, and the other end of the torsional spring is in contact with a clamping plate of the elastic sheet; and one end of the fuse is connected to the upper sleeve, and the other end of the fuse passes through the fuse tube, bypasses the elastic sheet and then is fixed on the connecting plate. According to the drop-out fuse, the problem that different types of fuses are not compatible and universal due to different lengths is solved, the universality is improved, the fuse wire is simple to fix and convenient to replace and operate, the fuse wire is not easy to wear, the service life can be prolonged, and the cost is saved.

Description

Technical Field

[0001] This invention relates to the field of power facility technology, and in particular to a drop-out fuse with adjustable fuse tube length. Background Technology

[0002] Drop-out fuses, as a key power distribution protection device, are widely used in 10kV distribution line branches and some factory and commercial substations. They are primarily used for short-circuit protection, load disconnection, and line control and isolation. They possess advantages such as reliable protection, convenient operation, flexible maintenance, and status visualization, playing a vital role in power distribution systems. However, in practical applications, the use and maintenance of drop-out fuses still face some pressing issues that need to be addressed: First, when replacing drop-out fuses or fuse wires, it is usually necessary to remove the entire fuse tube. Because there are many different models and lengths of fuse tubes on the market, mismatched fuse tube lengths can easily occur during on-site replacement, leading to installation difficulties and affecting equipment restoration and power supply continuity.

[0003] Secondly, the method of securing the fuse inside the fuse tube is rather cumbersome. Existing structures typically use a lower stationary contact spring, a hexagonal screw, and two pressure plates to secure the fuse. When replacing the fuse, the operator must use a wrench to loosen the hexagonal screw, rewrap the fuse, and then tighten it again. The entire process is complex, time-consuming, and not conducive to rapid maintenance and emergency handling.

[0004] Furthermore, current fuses require the fuse wire to remain taut throughout normal operation. Prolonged stress can lead to aging and even cracking of the fuse wire material, affecting not only the performance of the fuse itself but also potentially reducing the overall reliability of the fuse, thus threatening the safe and stable operation of the power distribution system.

[0005] In summary, existing drop-out fuses still have shortcomings in terms of fuse tube compatibility, fuse replacement convenience, and long-term operational reliability. There is an urgent need for an improved solution with a more reasonable structure, simpler operation, and higher reliability. Summary of the Invention

[0006] To overcome the aforementioned shortcomings in the prior art, the present invention provides a drop-out fuse with adjustable fuse tube length. This drop-out fuse solves the problem that different models of fuses cannot be used interchangeably due to different lengths, increases versatility, simplifies fuse fixing, facilitates replacement, and prevents fuse wear, thus extending service life and saving costs.

[0007] The technical solution of this invention is: a drop-out fuse with adjustable fuse tube length, comprising a fuse tube and a fuse wire, wherein the two ends of the fuse tube are respectively connected to an upper sleeve and a lower sleeve, the lower sleeve comprising a lower stationary contact, two lower moving contacts and a spring, the lower stationary contact being fitted onto the outside of the fuse tube and the two being fastened together by screws; the middle part of the spring is connected to the two lower moving contacts through a spring hinge rod, the two lower moving contacts being connected together by a connecting plate, a torsion spring being fitted onto the outside of the spring hinge rod, one end of the torsion spring contacting the connecting plate and the other end contacting the retaining plate of the spring; one end of the fuse wire is connected to the upper sleeve, the other end passing through the fuse tube and around the spring before being fixed to the connecting plate; the fuse wire actuates the spring to compress the torsion spring, causing the retaining plate to contact the protrusion at the end of the lower stationary contact; Furthermore, a contact hinge rod passes through the lower stationary contact, and the two ends of the contact hinge rod are respectively connected to two lower moving contacts. A connecting post is fixed to the outside of the two lower moving contacts, and the connecting post is rotatably connected to the support of the drop switch.

[0008] Furthermore, a lower operating ring is provided on one side of the lower stationary contact, and the protrusion is located below the lower operating ring.

[0009] Furthermore, the spring includes a base plate, a main board is connected to one side of the upper part of the base plate, two side plates are connected to the middle of the main board on both sides respectively, and round holes are opened on both side plates. The spring hinge rod is connected to the round holes, and a clamping plate inclined to the opposite side of the side plate is connected to the upper end of the main board.

[0010] Furthermore, a through groove perpendicular to the motherboard is formed at the center of the bottom surface of the base plate. The through groove is used to place a fuse, and the bottom of the motherboard matches the shape of the through groove.

[0011] Furthermore, the upper sleeve includes a pressure relief cap, which is threadedly connected to the upper end of the fuse tube. The upper end of the fuse is connected to a pressure plate, which is pressed between the pressure relief cap and the fuse tube.

[0012] Furthermore, the upper sleeve also includes an upper stationary contact and an upper moving contact. The upper stationary contact is connected to the outside of the upper end of the fuse tube. One side of the upper stationary contact is connected to an upper operating ring, and the other side is rotatably connected to a contact rod. The end of the contact rod is connected to the upper moving contact, and the upper end of the upper moving contact is connected to the slot of the drop switch.

[0013] Furthermore, a contact torsion spring is sleeved on the outside of the contact connecting rod. One end of the contact torsion spring is fixed to the contact connecting rod, and the other end is connected to the upper moving contact.

[0014] Furthermore, when the fuse blows, the spring is pushed outward by the force of the torsion spring, the retaining plate separates from the protrusion of the lower stationary contact, and the fuse tube falls due to gravity, causing the upper moving contact to fall out of the slot of the drop switch, thus breaking the circuit.

[0015] Furthermore, when replacing the fuse, use an insulating rod to pull down the upper operating ring, causing the upper stationary contact and fuse tube to move down, so that the upper moving contact falls out of the slot of the drop-out switch, breaking the circuit; then use the insulating rod to lift the lower operating ring, so that the connecting post disengages from the support, and the fuse can be removed.

[0016] The present invention has the following beneficial effects: Due to the above-mentioned solution, in the drop-out fuse of the present invention, the lower stationary contact is fitted outside the fuse tube. The position of the lower stationary contact on the fuse tube can be adjusted by tightening and loosening the wing screws, thereby ensuring that fuse tubes of various lengths can be matched with circuits or equipment, solving the problem of incompatibility between different fuse models due to their different lengths. Simultaneously, because the position of the lower stationary contact on the fuse tube is adjustable, different fuse tube models can be compatible with different environments, saving procurement costs, reducing the time spent selecting fuse tube models, and improving work efficiency. Since wing screws are used in all parts requiring tightening and loosening, screws can be tightened by hand even if tools are forgotten on the construction site, making operation convenient. Furthermore, fuse fixing is simple, replacement is convenient, and the fuse is not easily worn, extending its service life and saving costs. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is the front view of the lower sleeve; Figure 3 This is the right view of the lower sleeve; Figure 4 This is a top view of the lower sleeve; Figure 5 It is a 3D diagram of the shrapnel; Figure 6 This is the front view of the upper sleeve; Figure 7 This is the right view of the upper sleeve.

[0018] In the diagram, 1-upper sleeve, 2-lower sleeve, 3-fuse tube, 4-fuse, 101-upper moving contact, 102-upper operating ring, 103-pressure relief cap, 104-contact connecting rod, 105-contact torsion spring, 106-washer, 107-upper stationary contact, 201-lower operating ring, 202-lower stationary contact, 203-lower moving contact, 204-spring, 205-spring hinge rod, 206-first wing screw, 207-contact hinge rod, 208-connecting post, 209-connecting plate, 210-second wing screw, 211-clamping plate, 212-main plate, 213-base plate, 214-round hole, 215-side plate, 216-protrusion, 217-slot, 218-torsion spring. Detailed Implementation

[0019] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. The technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] In the description of this invention, it is necessary to understand that the orientations or positional relationships indicated by terms such as "upper," "lower," "left," "right," "inner," "outer," "top," and "bottom" are based on the orientations or positional relationships shown in the accompanying drawings. They are intended only to facilitate the description of this invention and to simplify the description, and are not intended to indicate or imply that the components referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0021] Depend on Figures 1 to 7 As shown, a drop-out fuse with adjustable fuse tube length includes a fuse tube 3 and a fuse 4. The two ends of the fuse tube 3 are respectively connected to an upper sleeve 1 and a lower sleeve 2. The upper sleeve 1 is connected to the slot of the drop-out switch, and the lower sleeve 2 is connected to the support of the drop-out switch. The fuse 4 passes through the fuse tube 3 and its two ends are connected to the upper sleeve 1 and the lower sleeve 2, thereby connecting the two ends of the drop-out switch to form a circuit.

[0022] The upper sleeve 1 includes a pressure relief cap 103, an upper stationary contact 107, and an upper moving contact 101. The outer surface of the upper end of the fuse tube 3 is threaded, and the pressure relief cap 103 is threaded to the outside of the upper end of the fuse tube 3. A pressure plate is welded to the upper end of the fuse 4, and the diameter of the pressure plate is larger than the inner diameter of the pressure relief cap 103 and smaller than the outer diameter of the pressure relief cap 103. When the lower end of the fuse 4 passes through the fuse tube 3, the pressure plate is located on the upper end surface of the fuse tube 3. When the pressure relief cap 103 is tightened, the pressure plate is pressed between the fuse tube 3 and the pressure relief cap 103, thereby fixing the upper end of the fuse 4.

[0023] The upper stationary contact 107 is fixed to the outer side of the upper end of the fuse tube 3. An upper operating ring 102 is fixed to one side of the outer surface of the upper stationary contact 107, and a rotatable contact rod 104 is connected to the other side. The end of the upper operating ring 102 is a circular ring structure, tilted downwards, to facilitate operation from below using an insulating rod. The end of the contact rod 104 is connected to the upper moving contact 101. One end of the upper moving contact 101 is connected to the contact rod 104, and the other end is located in the slot of the drop-out switch. A contact torsion spring 105 is provided on the outside of the contact connecting rod 104. One end of the contact torsion spring 105 is fixed to the contact connecting rod 104, and the other end is locked onto the upper moving contact 101. To prevent the contact torsion spring 105 from falling off and to ensure reliable operation, a washer 106 is provided between the end of the contact torsion spring 105 and the upper moving contact 101. In its free state, the contact torsion spring 105 pops outward, pressing the end of the upper moving contact 101 into the slot to ensure circuit continuity. When it is necessary to manually cut off the fuse, simply pull the upper operating ring 102 with the insulating rod, which will cause the fuse tube 3 to move downward through the upper stationary contact 107, causing the upper moving contact 101 to disengage from the slot of the drop-out switch, thus achieving power cut-off.

[0024] The lower sleeve 2 includes a lower stationary contact 202, two lower moving contacts 203, and a spring 204. The lower stationary contact 202 is fitted onto the outside of the fuse tube 3 and can move up and down along the fuse tube 3 to adjust the tightness of the fuse 4. The lower stationary contact 202 has two threaded holes on its side wall, into which a first wing screw 206 is connected. The first wing screw 206 passes through the side wall of the lower stationary contact 202, with its end abutting against the outer surface of the fuse tube 3. After the lower stationary contact 202 moves to a suitable position along the fuse tube 3, tightening the first wing screw 206 on the lower stationary contact fixes the lower stationary contact 202 to a specific position on the fuse tube 3. This adjustable structure allows for adjustment of the effective length of the fuse tube, ensuring that fuse tubes of various lengths can be matched with circuits or equipment. Typically, two first wing screws 206 are used, located on the same circumferential surface. Preferably, the arc angle between the two first wing screws 206 is 90 degrees, and they are installed in a position that is easy to operate. When tightening or loosening, the two wing screws 206 are operated in sequence to achieve the tightening or loosening of the lower stationary contact 202 and the fuse tube 3.

[0025] A lower operating ring 201 is fixed to one side of the outer wall of the lower stationary contact 202, and the annular surface of the lower operating ring 201 is coplanar with the main axis of the lower stationary contact 202. A protrusion 216 is provided below the lower operating ring 201, and the side of the protrusion 216 facing the lower stationary contact 202 is a plane.

[0026] A circular hole is provided on the side of the lower stationary contact 202 near the lower operating ring 201. A contact hinge rod 207 passes through the circular hole. The two ends of the contact hinge rod 207 are respectively connected to two lower moving contacts 203. Both the lower stationary contact 202 and the lower moving contact 203 can rotate along the contact hinge rod 207.

[0027] The lower moving contact 203 is a long strip plate located on both sides of the lower stationary contact 202. The lower parts of the two lower moving contacts 203 are connected by a connecting plate 209. A connecting post 208 is fixed to the outer side of the lower end of each lower moving contact 203, and the connecting post 208 is rotatably connected to the support of the drop switch.

[0028] The spring contact 204 includes a base plate 213, with a main board 212 connected to one side of the base plate 213 at a right angle. Two side plates 215 are connected to the middle of the main board 212 on both sides, with the two side plates 215 and the base plate 213 located on the same side of the main board 212. Each side plate 215 has a circular hole 214, with a spring contact hinge rod 205 connected to the circular hole 214. The spring contact 204 can rotate along the spring contact hinge rod 205. An inclined retaining plate 211 is connected to the upper end of the main board 212. The retaining plate 211 is inclined to the opposite side of the side plates 215, and the surface of the retaining plate 211 on the side of the base plate 213 contacts a protrusion 216 on the lower stationary contact 202.

[0029] The spring piece 204 is connected to two lower moving contacts 203 via a spring piece hinge rod 205, and the two lower moving contacts 203 can rotate around the spring piece hinge rod 205. A torsion spring 218 is sleeved on the outside of the spring piece hinge rod 205. One end of the torsion spring 218 contacts the connecting plate 209, and the other end contacts the locking plate 211. In a free state, the torsion spring 218 springs outward, causing the locking plate 211 to disengage from the protrusion 216. When the spring piece 204 is subjected to external force, it compresses the torsion spring 218, causing the locking plate 211 to press against the protrusion 216.

[0030] One end of the fuse 4 is connected to the upper sleeve 1, and the other end passes through the fuse tube 3 and around the bottom of the spring piece 204, and is fixed to the connecting plate 209 by the wing screw 210; the fuse 4 drives the spring piece 204 to compress the torsion spring 218, so that the clamping plate 211 contacts the protrusion 216 at the end of the lower stationary contact 202.

[0031] To prevent the fuse 4 from moving left and right when it passes around the bottom of the spring 204, a through slot perpendicular to the main board 212 can be formed at the center of the bottom surface of the base plate 213, and the bottom of the main board 212 matches the shape of the through slot. The fuse 4 can pass through the through slot and be connected to the connecting plate 209, which can prevent the fuse 4 from moving along the base plate 213 and wearing out.

[0032] As another embodiment, see Figure 5The base plate 213 comprises two base plate units, each inclined upwards at one center and downwards on both sides, forming a groove between them. The bottom shape of the main plate 212 is also adapted to the base plate 213. The fuse 4 can pass through the groove, preventing lateral movement and reducing wear. Additionally, a slot 217 or hole can be formed in the center of the base plate to further reduce wear on the fuse 4.

[0033] When the drop-out fuse is connected, the upper moving contact 101 is engaged in the slot of the drop-out switch. The upper end of the fuse 4 is connected to the top of the fuse tube 3, and the lower end extends from the bottom of the fuse tube 3, passes around the spring 204, and is pressed onto the connecting plate 209 by the second wing screw 210. Under the tension of the fuse 4, the spring 204 compresses the torsion spring 208, causing the retaining plate 211 to press against the protrusion 216 of the lower stationary contact 202. At the same time, the two connecting posts 208 are connected to the support of the drop-out switch, thereby realizing the connection of the drop-out switch.

[0034] When fuse 4 melts, spring 204 loses the restraint of fuse 4 and springs outward under the force of torsion spring 218, causing the retaining plate 211 to disengage from the protrusion 216 of the lower stationary contact 202; the lower end of fuse tube 3 loses support and falls under its own weight, causing the upper moving contact 101 to fall out of the slot, breaking the circuit and cutting off the faulty line or faulty equipment.

[0035] When the fuse needs to be replaced, pull down the upper operating ring 102 with the insulating rod. The upper operating ring 102 drives the fuse tube 3 to fall through the upper stationary contact 107, causing the upper moving contact 101 to disengage from the slot and the circuit to be broken. Then, lift the lower operating ring 201 with the insulating rod. The lower operating ring 201 drives the lower moving contact 203 to move upward, causing the connecting post 208 to disengage from the support, thus allowing the drop-out fuse to be removed from the line or equipment.

[0036] In the drop-out fuse of this invention, the lower stationary contact 202 is fitted onto the outside of the fuse tube 3. The position of the lower stationary contact 202 on the fuse tube 3 can be adjusted by tightening and loosening two first wing screws 206, ensuring that fuse tubes of various lengths can be matched with the circuit or equipment. This solves the problem of incompatibility between different fuse models with varying lengths. Furthermore, since the position of the lower stationary contact 202 on the fuse tube is adjustable, different fuse tube models can be compatible with different environments, saving procurement costs, reducing the time spent selecting fuse tube models, and improving work efficiency. Because wing screws are used at all locations requiring tightening and loosening, screws can be tightened by hand even if tools are forgotten on-site, making operation convenient. Grooves and through holes are provided at the location where the fuse wire passes over the spring contact, reducing the friction surface between the fuse wire and the spring contact, thereby extending fuse life, saving costs, and ensuring power supply quality.

[0037] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A drop-out fuse with adjustable fuse tube length, comprising a fuse tube (3) and a fuse (4), characterized in that: The fuse tube (3) is connected to an upper sleeve (1) and a lower sleeve (2) at both ends. The lower sleeve (2) includes a lower stationary contact (202), two lower moving contacts (203), and a spring (204). The lower stationary contact (202) is fitted onto the outside of the fuse tube (3) and the two are fastened together by screws. The spring (204) is connected to the two lower moving contacts (203) in the middle by a spring hinge rod (205). The two lower moving contacts (203) are connected by a connecting plate (209). (205) An external torsion spring (218) is fitted. One end of the torsion spring (218) contacts the connecting plate (209), and the other end contacts the retaining plate (211) of the spring (204). One end of the fuse (4) is connected to the upper sleeve (1), and the other end passes through the fuse tube (3) and around the spring (204) before being fixed to the connecting plate (209). The fuse (4) drives the spring (204) to compress the torsion spring (218), so that the retaining plate (211) contacts the protrusion (216) at the end of the lower stationary contact (202).

2. The adjustable fuse tube length drop-out fuse according to claim 1, characterized in that: The lower stationary contact (202) passes through the contact hinge rod (207), and the two ends of the contact hinge rod (207) are respectively connected to the two lower moving contacts (203). The two lower moving contacts (203) are respectively fixed with connecting posts (208) on their outer sides. The connecting posts (208) are rotatably connected to the support of the drop switch.

3. The adjustable fuse tube length drop-out fuse according to claim 1, characterized in that: The lower stationary contact (202) has a lower operating ring (201) on one side, and the protrusion (216) is located below the lower operating ring (201).

4. The adjustable fuse tube length drop-out fuse according to claim 1, characterized in that: The spring (204) includes a base plate (213), a main plate (212) is connected to the upper side of the base plate (213), two side plates (215) are connected to the middle sides of the main plate (212), and two round holes (214) are opened on the two side plates (215). The spring hinge rod (205) is connected to the round hole (214), and a card plate (211) inclined to the opposite side of the side plate (215) is connected to the upper end of the main plate (212).

5. The adjustable fuse tube length drop-out fuse according to claim 4, characterized in that: The bottom plate (213) has a through groove at the center of its bottom surface that is perpendicular to the main plate (212). The through groove is used to place the fuse (4). The bottom of the main plate (212) matches the shape of the through groove.

6. The adjustable fuse tube length drop-out fuse according to claim 1, characterized in that: The upper sleeve (1) includes a pressure relief cap (103), which is threaded to the upper end of the fuse tube (3). The upper end of the fuse (4) is connected to a pressure plate, which is pressed between the pressure relief cap (103) and the fuse tube (3).

7. The adjustable fuse tube length drop-out fuse according to claim 6, characterized in that: The upper sleeve (1) also includes an upper stationary contact (107) and an upper moving contact (101). The upper stationary contact (107) is connected to the outside of the upper end of the fuse tube (3). One side of the upper stationary contact (107) is connected to the upper operating ring (102), and the other side is rotated to connect to the contact rod (104). The end of the contact rod (104) is connected to the upper moving contact (101), and the upper end of the upper moving contact (101) is connected to the slot of the drop switch.

8. The adjustable fuse tube length drop-out fuse according to claim 7, characterized in that: The contact link (104) is fitted with a contact torsion spring (105). One end of the contact torsion spring (105) is fixed to the contact link (104), and the other end is connected to the upper moving contact (101).

9. The adjustable fuse tube length drop-out fuse according to any one of claims 1-8, characterized in that: When the fuse (4) melts, the spring (204) springs outward under the elastic force of the torsion spring (218), the plate (211) separates from the protrusion (216) of the lower stationary contact (202), and the fuse tube (3) falls due to gravity, causing the upper moving contact (101) to fall out of the slot of the drop switch, and the circuit is disconnected.

10. The adjustable fuse tube length drop-out fuse according to any one of claims 1-8, characterized in that: When replacing the fuse, use an insulating rod to pull down the upper operating ring (102), which will cause the upper stationary contact (107) and fuse tube (3) to move down, so that the upper moving contact (101) will fall out of the slot of the drop switch and the circuit will be disconnected; then use an insulating rod to lift the lower operating ring (201), so that the connecting post (208) will be disengaged from the support, and the fuse can be disassembled.

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