A direct current fuse

Abstract

The utility model provides a kind of DC fuse. When the DC fuse needs to replace internal fuse core, the end cap of one side is disassembled, then the broken fuse core is taken out, then the new fuse core is inserted, one end of the fuse core is inserted between the arc-shaped insertion metal sheet of the end cap which is not screwed off or screwed off and cleaned and continues to be inserted and connected with one end of the insulating shell, while the fuse core is limited by limiting structure, it is also convenient for the other end of the fuse core to be inserted between the arc-shaped insertion metal sheet of the other end cap, then the end cap is inserted through the other end of the insulating shell, at this time, the cooperation of positioning groove and insulating positioning column realizes the quick positioning and stable connection of end cap, then the end cover continues to press down and install, the annular rubber ring provided on the insulating shell is expanded in the annular groove provided on the side wall of the end cap, so as to form a tightly matched sealing connection structure, effectively prevent dust, moisture and other external impurities from entering the inside of the fuse, and improve its overall protection performance and environmental adaptability.

Description

Technical Field

[0001] This utility model relates to the field of fuse technology, specifically a DC fuse. Background Technology

[0002] A fuse is an electrical protection device that automatically cuts off the circuit by melting its fusible element when the current exceeds a specified value. Its working principle is as follows: when the current exceeds a set value for a certain period, the current flowing through the fusible element raises its temperature to its melting point, causing the element to melt and interrupting the current, thus protecting the circuit and equipment. Fuses have advantages such as simple structure, rapid response, and reliable protection, and are therefore widely used in high and low voltage power distribution systems, control systems, and various electrical equipment. They are one of the most common and basic short-circuit and overload protection devices.

[0003] However, existing fuses typically employ a one-piece sealed structure, with the internal fuse element (also known as the fusible link) non-removably encapsulated within an insulating casing. When the fusible link melts due to a fault current, the entire fuse must be replaced, increasing maintenance costs. Furthermore, the damaged fuse casing is often made of non-recyclable materials, such as thermosetting plastics, which can pollute the environment and fail to meet current green and sustainable development requirements. Therefore, it is necessary to provide a DC fuse with a detachable structure that facilitates fuse element replacement, thereby reducing replacement costs, improving maintenance efficiency, and enhancing environmental adaptability. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides a DC fuse that effectively improves the problems of high maintenance costs and poor environmental performance of some traditional DC fuses.

[0005] A DC fuse includes a pair of end caps, a fuse element, and an insulating shell. The end caps are snapped onto both ends of the insulating shell. A positioning groove is provided on the side of the end cap near the insulating shell. A pair of opposing arc-shaped insert metal pieces are provided in the middle of the end cap. At least one annular groove is recessed on the inner side of the side wall of the end cap towards the outer side. An insulating positioning post adapted to the positioning groove is provided on the side inside the insulating shell. A limiting structure for limiting the fuse element is provided inside the insulating shell. An annular fixing groove is recessed inward on the outer side walls at both ends of the insulating shell. An annular rubber ring is fitted on the annular fixing groove and tightened to the annular groove.

[0006] Preferably, the fused core is cylindrical, with a metal contact piece installed at each end, and a metal guide wire is provided inside. The metal guide wire is in communication with the metal contact piece, and the metal contact piece is inserted between the arc-shaped insert metal pieces.

[0007] Furthermore, the arc-shaped insert metal sheet includes a first arc-shaped segment, a straight segment connected to the first arc-shaped segment, and a second arc-shaped segment connected to the other end of the straight segment. The first arc-shaped segments of the two arc-shaped insert metal sheets are welded to the end cap, the straight segments of the two arc-shaped insert metal sheets abut against each other, and the second arc-shaped segments of the two arc-shaped insert metal sheets are arranged opposite each other with a gap.

[0008] Preferably, the limiting structure includes multiple sets of opposing arc-shaped fixing members disposed inside the insulating shell, wherein two of the arc-shaped fixing members are arranged as a group and located on the same horizontal plane.

[0009] Furthermore, multiple telescopic springs are evenly connected between the side of the arc-shaped fixing member away from the other arc-shaped fixing member and the inner wall of the insulating shell.

[0010] Preferably, the number of both the annular groove and the annular rubber ring is set to two.

[0011] Preferably, the maximum diameter of the two outermost annular rubber rings of the insulating shell is smaller than the maximum diameter of the two inner annular rubber rings of the insulating shell.

[0012] Preferably, the end cap is a copper end cap, and the outer side of the end cap is coated with a silver layer.

[0013] Preferably, the inner surface of the insulating shell is further provided with a ceramic coating layer, the thickness of which is 50-100 μm.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] This utility model provides a DC fuse comprising a pair of end caps, a fuse element, and an insulating shell. When the internal fuse element needs to be replaced, one end cap is removed, the faulty fuse element is taken out, and a new fuse element is inserted. One end of the fuse element is inserted between the arc-shaped insertion metal piece of the other end cap that has not been unscrewed or has been cleaned and continues to be inserted into the insulating shell. Simultaneously, the fuse element is restricted by a limiting structure, which also facilitates the insertion of the other end of the fuse element between the arc-shaped insertion metal pieces of the other end cap. The end cap is then inserted through the other end of the insulating shell. At this point, the positioning groove and the insulating positioning post cooperate to achieve rapid positioning and stable connection of the end cap. The end cap is then pressed down for installation. The annular rubber ring on the insulating shell expands and tightens at the annular groove on the side wall of the end cap, forming a tightly sealed connection structure. This effectively prevents dust, moisture, and other external impurities from entering the fuse, improving its overall protective performance and environmental adaptability. After installation, the fuse element is reliably positioned by the limiting structure, preventing displacement or loosening during use and ensuring a stable and reliable electrical connection. Therefore, the DC fuse provided by the utility model has the advantages of detachable structure, convenient replacement of fuse element, good sealing performance, strong assembly stability, and avoidance of material waste. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the cross-sectional structure of the DC fuse described in this utility model;

[0017] Figure 2 This is a top view of the insulating shell of the present invention.

[0018] in:

[0019] 10-End cap, 20-Fuse core, 30-Insulating shell, 40-Arc-shaped plug-in metal piece, 50-Annular groove, 60-Annular fixing groove, 70-Annular rubber ring, 80-Arc-shaped fixing piece, 21-Metal contact piece, 41-First arc-shaped section, 42-Straight section, 43-Second arc-shaped section. Detailed Implementation

[0020] The embodiments described below are merely some embodiments of this utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

[0021] See Figure 1 as well as Figure 2This embodiment provides a DC fuse, comprising a pair of end caps 10, a fuse element 20, and an insulating shell 30. The end caps 10 are fastened to both ends of the insulating shell 30. A positioning groove is provided on the side of the end cap 10 near the insulating shell 30. A pair of opposing arc-shaped insert metal pieces 40 are provided in the middle of the end cap 10. At least one annular groove 50 is recessed on the inner side of the side wall of the end cap 10 towards the outer side. An insulating positioning post adapted to the positioning groove is provided on the side inside the insulating shell 30. A limiting structure for limiting the fuse element 20 is provided inside the insulating shell 30. An annular fixing groove 60 is recessed inward on the outer side wall of both ends of the insulating shell 30. An annular rubber ring 70 is fitted on the annular fixing groove 60 and is tightly connected to the annular groove 50.

[0022] Preferably, the fusible core 20 is cylindrical, with a metal contact piece 21 installed at each end. A metal guide wire is provided inside the core, and the metal guide wire is electrically connected to the metal contact piece 21. The metal contact piece 21 is inserted between the arc-shaped insert metal pieces 40. The metal guide wire serves as the current-breaking path, and its material can be a low-melting-point metal or alloy, such as silver, copper, tin, or their alloys. Its size and length are determined according to the expected rated breaking current. The two ends of the metal guide wire are electrically connected to the metal contact piece 21, preferably fixed by welding or brazing to ensure stable conduction and reliable contact. Simultaneously, the metal contact piece 21 is connected to the arc-shaped insert metal piece 40 in the end cap 10 via a plug-in structure, allowing for plug-and-play operation. This not only ensures a stable conductive connection between the fusible core 20 and the end cap 10 but also allows for tool-free insertion and removal during fusible core 20 replacement, improving maintenance efficiency and structural convenience.

[0023] Furthermore, the arc-shaped insert metal piece 40 includes a first arc-shaped segment 41, a straight segment 42 connected to the first arc-shaped segment 41, and a second arc-shaped segment 43 connected to the other end of the straight segment 42. The first arc-shaped segments 41 of the two arc-shaped insert metal pieces 40 are welded to the end cap 10, the straight segments 42 of the two arc-shaped insert metal pieces 40 abut against each other, and the second arc-shaped segments 43 of the two arc-shaped insert metal pieces 40 are arranged opposite each other with a gap. During the assembly process, the metal contacts 21 at both ends of the fused core 20 are first inserted through the gap between the second arc-shaped segments 43. During the insertion process, the arc-shaped segments have a limited elastic opening capacity. When the metal contacts 21 continue to be inserted and contact the straight segment 42, under appropriate pressing force, the metal contacts 21 are pressed and embedded between the two straight segments 42, thereby achieving a stable and highly conductive electrical connection. Therefore, the arc-shaped plug-in metal piece 40 not only allows the metal contact piece 21 to be quickly inserted and removed, but also effectively prevents loosening or detachment at the connection point due to vibration, thermal expansion and contraction through the clamping action of the straight section 42, further improving the reliability and structural stability of the connection. In addition, since the metal contact piece 21 and the plug-in metal piece have an elastic snap-fit ​​structure, it is also convenient for the replacement and maintenance of the fuse 20 in the later stage, improving the maintainability and service life of the whole machine. It should be noted that in an emergency, if the fuse 20 cannot be found, a thin copper wire can be used as a fuse 20 for emergency use. When using copper wire, the copper wire needs to be set longer so that the end of the copper wire is clamped between the plug-in metal pieces or can be wrapped around the arc-shaped plug-in metal piece 40. The longer length means that the copper wire needs to be threaded into the insulating shell 30 first, and after the two ends of the copper wire are connected to the arc-shaped plug-in metal piece 40, the end cap 10 is then inserted into the insulating shell 30.

[0024] Preferably, the limiting structure includes multiple sets of opposing arc-shaped fixing members 80 disposed inside the insulating shell 30, wherein two arc-shaped fixing members 80 are arranged as a group and located on the same horizontal plane. The two arc-shaped fixing members 80 are symmetrically distributed on both radial sides of the fused core 20, and their curvature is adapted to the outer surface contour of the fused core 20, forming a partially enclosed clamping structure, thereby providing a stable limiting effect on the fused core 20 without affecting the insertion and removal operation of the fused core 20.

[0025] Furthermore, multiple telescopic springs are evenly connected between the side of the arc-shaped fixing member 80 away from the other arc-shaped fixing member 80 and the inner wall of the insulating shell 30. These telescopic springs provide the arc-shaped fixing member 80 with a certain elastic tension, allowing it to make appropriate clearance when the fused core 20 is inserted, and also clamping and fixing the fused core 20 after installation, preventing it from shaking, loosening, or axially slipping during transportation, vibration, or use. Of course, the arc-shaped fixing member 80 can also be fixedly connected to the insulating shell 30, which will not be elaborated upon here.

[0026] Preferably, the number of annular grooves 50 and annular rubber rings 70 is set to two. The maximum diameter of the two outermost annular rubber rings 70 of the insulating shell 30 is smaller than the maximum diameter of the two inner annular rubber rings 70 of the insulating shell 30. When the end cap 10 is inserted into the insulating shell 30, the outermost annular rubber ring 70 with a larger diameter forms a tight press fit with the annular groove 50 on the side wall of the end cap 10, achieving a tight connection; while the innermost smaller diameter rubber ring is fitted into the corresponding groove, providing secondary sealing and anti-dislodgement capability, thereby achieving step-by-step locking and multiple sealing as a whole, improving the tightness and stability of the connection. It should be noted that the diameter of the two outermost annular rubber rings 70 is smaller because the large annular fixing groove 60 on the end cap can first pass through this annular rubber ring 70 and then connect with the innermost large annular rubber ring 70.

[0027] Preferably, the end cap 10 is a copper end cap 10, and the outer side of the end cap 10 is coated with a silver layer. Copper has excellent electrical conductivity, which can effectively reduce resistance loss during current transmission and ensure low heat loss and high current carrying capacity of the fuse when energized; at the same time, copper itself has good mechanical strength, which can maintain the structural stability of the end cap 10 during plugging and unplugging connections and long-term operation.

[0028] Preferably, the inner surface of the insulating shell 30 is further provided with a ceramic coating layer, the thickness of which is 50-100μm, which can significantly improve the arc resistance and thermal shock resistance performance inside the fuse.

[0029] This utility model provides a DC fuse, which includes a pair of end caps 10, a fuse element 20, and an insulating shell 30 with a cylindrical structure having a through hole in the center. The damaged fuse 20 can be removed and replaced with a new one simply by removing one end cap 10. The operation is quick and easy. Then, the new fuse 20 is inserted, with one end of the fuse 20 inserted between the arc-shaped metal piece 40 of the end cap 10 that was not unscrewed or was unscrewed and cleaned and is still connected to one end of the insulating shell 30. At the same time, the fuse 20 is restricted by the limiting structure, which also makes it easy for the other end of the fuse 20 to be inserted between the arc-shaped metal pieces 40 of the other end cap 10. Then, the end cap 10 is inserted through the other end of the insulating shell 30. At this time, the positioning groove and the insulating positioning post cooperate to achieve quick positioning and stable connection of the end cap 10. Then, the end cap is pressed down for installation. The annular rubber ring 70 set on the insulating shell 30 is tightened at the annular groove 50 set on the side wall of the end cap 10, thereby forming a tight-fitting sealed connection structure, effectively preventing dust, water vapor and other external impurities from entering the fuse, improving its overall protection performance and environmental adaptability. After installation, the fuse element 20 is reliably positioned by the limiting structure, preventing displacement or loosening during use and ensuring a stable and reliable electrical connection. Therefore, the DC fuse provided by this utility model has advantages such as a detachable structure, convenient replacement of the fuse element 20, good sealing performance, strong assembly stability, and avoidance of material waste.

[0030] The above-disclosed embodiments are merely some preferred embodiments of the present utility model, and should not be construed as limiting the scope of the present utility model. Therefore, any equivalent changes made in accordance with the scope of the present utility model patent application shall still fall within the scope of the present utility model.

Claims

1. A DC fuse, characterized in that: The device includes a pair of end caps, a fusible core, and an insulating shell. The end caps are fastened to both ends of the insulating shell. A positioning groove is provided on the side of the end cap closest to the insulating shell. A pair of opposing arc-shaped insert metal pieces are provided in the middle of the end cap. At least one annular groove is recessed on the inner side of the side wall of the end cap towards the outer side. An insulating positioning post adapted to the positioning groove is provided on the side inside the insulating shell. A limiting structure for limiting the fusible core is provided inside the insulating shell. An annular fixing groove is recessed inward on the outer side wall of both ends of the insulating shell. An annular rubber ring is fitted on the annular fixing groove and tightened to the annular groove.

2. The DC fuse as described in claim 1, characterized in that, The fused core is cylindrical, with a metal contact piece installed at each end. A metal guide wire is provided inside the core, and the metal guide wire is connected to the metal contact piece. The metal contact piece is inserted between the arc-shaped insert metal pieces.

3. The DC fuse as described in claim 2, characterized in that, The arc-shaped insert metal sheet includes a first arc-shaped segment, a straight segment connected to the first arc-shaped segment, and a second arc-shaped segment connected to the other end of the straight segment. The first arc-shaped segments of the two arc-shaped insert metal sheets are welded to the end cap, the straight segments of the two arc-shaped insert metal sheets abut against each other, and the second arc-shaped segments of the two arc-shaped insert metal sheets are arranged opposite each other with a gap.

4. The DC fuse as described in claim 1, characterized in that, The limiting structure includes multiple sets of opposing arc-shaped fixing members disposed inside the insulating shell, wherein two of the arc-shaped fixing members are arranged as a group and located on the same horizontal plane.

5. The DC fuse as described in claim 4, characterized in that, Multiple telescopic springs are evenly connected between the side of the arc-shaped fastener away from the other arc-shaped fastener and the inner wall of the insulating shell.

6. The DC fuse as described in claim 1, characterized in that, The number of annular grooves and annular rubber rings is set to 2.

7. The DC fuse as described in claim 6, characterized in that, The maximum diameter of the two outermost annular rubber rings of the insulating shell is smaller than the maximum diameter of the two inner annular rubber rings of the insulating shell.

8. The DC fuse as described in claim 1, characterized in that, The end cap is made of copper and has a silver coating on its outer side.

9. The DC fuse as described in claim 1, characterized in that, The inner surface of the insulating shell is further provided with a ceramic coating layer, the thickness of which is 50-100 μm.

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