Safety fuse for electric vehicle charging facility

Abstract

The invention discloses a safety fuse for an electric vehicle charging facility, and relates to the technical field of circuit protection equipment, the safety fuse comprises a shell structure, a fuse body structure and an elastic mounting piece, the shell structure comprises a middle hole shell, detachable end covers are arranged at the two ends of the middle hole shell, round copper sheets are fixed at the two ends of a fuse body in the length direction, and the elastic mounting piece is arranged in the middle hole shell. A double-metal arc-shaped sheet is arranged between the two circular copper sheets, the other side of the fuse body is provided with a fusing feedback assembly, and the elastic installation part is arranged on the outer sides of the two circular copper sheets. Through the arrangement of the bimetallic arc-shaped sheet, when continuous overload occurs in a circuit, the bimetallic arc-shaped sheet is heated and bent, microcracks are generated in a fusing area in advance, the response delay of the fuse is reduced, and frequent starting and stopping of a quick charging pile are facilitated; the fuse feedback assembly can partially extend out of the middle hole shell and is used for prompting and feeding back maintenance personnel, and the fuse body can be replaced in time.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit protection devices, and particularly to a safety fuse for electric vehicle charging facilities. Background Art

[0002] With the rapid development of the global new energy vehicle industry, the large-scale construction and safe operation of electric vehicle charging facilities have become the core issues of concern in the industry. As the core component for overcurrent protection in the charging system, the reliability of the fuse directly affects the safety of the charging equipment and the battery system.

[0003] Traditional fuses generally use a rigid plug-in or fixed welding structure to achieve the electrical connection between the fuse element and the electrode. During the charging process of electric vehicles, affected by factors such as the vibration of the charging pile, especially the road surface vibration and cable plugging and unplugging stress under the working conditions of on-vehicle chargers, the contact interface between the fuse element and the electrode is prone to looseness, oxidation or an increase in the gap, resulting in an increase in the contact resistance.

[0004] In traditional fuses, when the circuit experiences continuous overload, under high-power pulse loads, there is often a problem of response delay, which is not conducive to the frequent start-stop conditions of fast chargers.

[0005] The insulating housings of existing fuses generally use ordinary epoxy resin materials. Insufficient heat dissipation performance leads to too high a temperature rise of the fuse element, low arc extinguishing efficiency, and after the fuse element melts, maintenance personnel cannot immediately determine the state of the fuse.

[0006] In view of this, the present invention is specifically proposed to solve the above technical problems. Summary of the Invention

[0007] The purpose of the present invention is to provide a safety fuse for electric vehicle charging facilities to solve the technical problems of easy loosening of the contact surface between the fuse element and the electrode and low arc extinguishing efficiency in the fuses of the prior art.

[0008] The purpose of the present invention is to provide a safety fuse for electric vehicle charging facilities, including: A housing structure, which includes a middle-hole housing. Removable end caps are provided at both ends of the middle-hole housing to form a receiving cavity, and electrode terminals are screwed onto the end caps; A fuse element structure, which is detachably installed in the receiving cavity. The fuse element structure includes a fuse element body. Circular copper sheets are fixed at both ends of the fuse element body in the length direction. A bimetallic arc-shaped sheet is provided between the two circular copper sheets and is located on one side of the fuse element body. A fuse-breaking feedback component is provided on the other side of the fuse element body; An elastic mounting member, which is provided outside the two circular copper sheets, and the outer end of the elastic mounting member is electrically connected to the electrode terminal.

[0009] Furthermore, the melt structure also includes an insulating protective sleeve sleeved on the melt body, and two ends of the insulating protective sleeve are respectively abutted against the inner sides of the two circular copper sheets.

[0010] Furthermore, a plurality of heat sinks are sleeved on the outer circumference of the insulating protective sleeve along its length direction.

[0011] Furthermore, two positioning convex strips are symmetrically arranged between the two circular copper sheets, the positioning convex strips are U-shaped structures, and the two ends of the U-shaped structure are respectively connected to the two circular copper sheets, and the heat sink is located inside the U-shaped structure; Positioning slots are arranged on both end surfaces of the inner side of the central hole shell, and two positioning convex strips are detachably arranged in the two positioning slots.

[0012] Further, the fuse feedback assembly includes a metal wire connected to the middle of the fuse body; A trigger pin is connected to one end of the metal wire facing away from the melt body; A connecting plate with sliding connection is sleeved on the trigger pin, and the four corners of the connecting plate are fixed on the inner wall of the central hole shell through columns; A spring is arranged between the inner wall of the central hole shell and the connecting plate, the spring is sleeved on the trigger pin, and the two ends of the spring are respectively fixed on the connecting plate and the outer wall of the trigger pin; A feedback hole coaxial with the trigger pin is arranged on the middle hole shell, and at least a part of the upper end of the trigger pin is located in the feedback hole.

[0013] Furthermore, a plurality of metal grids are arranged on the inner wall of the central hole shell on the side away from the trigger pin, and the plurality of metal grids are evenly arranged along the length direction of the central hole shell, and the metal grids are arranged obliquely.

[0014] Furthermore, the inner wall of the insulating protective sleeve is coated with a gas-generating ceramic coating.

[0015] Furthermore, the elastic mounting part includes a metal telescopic rod, one end of which is electrically connected to the corresponding electrode terminal, and the other end of the metal telescopic rod is provided with a contact copper sheet, which is fixedly connected to the corresponding circular copper sheet, and a buffer spring is installed between the contact copper sheet and the metal telescopic rod.

[0016] Furthermore, an annular flange is provided at one end of the electrode terminal away from the end cover, and a plurality of mounting holes are evenly distributed on the annular flange. The annular flange is mounted on the mounting plate of the charging device through countersunk bolts and the mounting holes.

[0017] Furthermore, the outer surface of the electrode terminal is silver-plated or tin-plated.

[0018] By adopting the above technical solution, the present invention has the following beneficial effects: 1. By arranging detachable end covers at both ends of the central hole shell, it is convenient to disassemble the shell structure, thereby disassembling and replacing the melt body.

[0019] 2. By providing the bimetallic arc-shaped piece, when continuous overload occurs in the circuit, the bimetallic arc-shaped piece is heated and bent, causing microcracks to be generated in advance in the fusing area, reducing the response delay of the fuse, and facilitating the frequent start and stop of the fast charging pile.

[0020] 3. By providing the elastic mounting member, when the electric vehicle vibrates during charging, the elastic mounting member buffers and dampens the melt body, preventing the melt body from disconnecting from the electrode terminal and preventing the contact resistance between the melt body and the electrode terminal from increasing.

[0021] 4. By providing the fusing feedback component, after the melt body fuses, the fusing feedback component can partially extend out of the middle-hole housing, used to prompt and feedback to the maintenance personnel, so that the melt body can be replaced in time to ensure the stable operation of the charging pile. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings, as a part of this application, are used to provide a further understanding of the present invention. The schematic embodiments and descriptions thereof of the present invention are used to explain the present invention, but do not constitute an improper limitation to the present invention. Obviously, the drawings in the following description are only some embodiments. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts. In the drawings: Figure 1 is a schematic structural diagram of a safety fuse for an electric vehicle charging facility provided by an embodiment of this application; Figure 2 is Figure 1 a schematic structural diagram of the safety fuse for an electric vehicle charging facility provided after removing the middle-hole housing; Figure 3 is Figure 2 a schematic structural diagram of another perspective; Figure 4 is an internal structural diagram of the melt structure of a safety fuse for an electric vehicle charging facility provided by an embodiment of this application; Figure 5 is a schematic structural diagram of the middle-hole housing of a safety fuse for an electric vehicle charging facility provided by an embodiment of this application.

[0023] Reference numerals: 1, middle-hole housing; 2, end cover; 3, electrode terminal; 4, feedback hole; 5, positioning rib; 6, insulating protective sleeve; 7, circular copper sheet; 8, contact copper sheet; 9, metal telescopic rod; 10, buffer spring; 11, heat sink; 12, metal grid; 13, metal wire; 14, trigger pin; 15, connecting plate; 16, spring; 17, melt body; 18, bimetallic arc-shaped piece; 19, positioning card slot.

[0024] It should be noted that these drawings and text descriptions are not intended to limit the scope of the concept of the present invention in any way, but to illustrate the concept of the present invention to those skilled in the art by referring to specific embodiments. Detailed Description of the Invention

[0025] The specific embodiments of the present invention will be further described in detail with reference to the accompanying drawings.

[0026] Referring to Figures 1 to 5 As shown, an embodiment of the present application provides a safety fuse for an electric vehicle charging facility, including: a housing structure, a fuse element structure, and an elastic mounting member. The housing structure includes a middle-hole housing 1, and detachable end caps 2 are provided at both ends of the middle-hole housing 1 to form a receiving cavity. An electrode terminal 3 is screwed on the end cap 2. The fuse element structure is detachably installed in the receiving cavity. The fuse element structure includes a fuse element body 17. Circular copper sheets 7 are fixed at both ends of the fuse element body 17 in the length direction. A bimetallic arc-shaped sheet 18 is provided between the two circular copper sheets 7 and is located on one side of the fuse element body 17. A fuse-breaking feedback component is provided on the other side of the fuse element body 17. The elastic mounting member is provided outside the two circular copper sheets 7, and the outer end of the elastic mounting member is electrically connected to the electrode terminal 3.

[0027] It should be noted that the middle-hole housing 1 is made of an insulating and high-temperature-resistant epoxy resin material, which has good insulation performance and high-temperature resistance and can work stably in the high-temperature environment of the electric vehicle charging facility. An O-ring is provided at the screwed joint of the end cap 2 and the electrode terminal 3 to prevent the entry of dust and water; the end cap 2 and the middle-hole housing 1 are fixedly connected by a plurality of fastening bolts, which is convenient for disassembling and replacing the fuse element structure; the fuse element body 17 is a rectangular sheet structure, and the material is lead-tin alloy. The middle part thereof is a weak fuse-breaking area with a gradually changing width. The weak area preferentially fuses during overload. When abnormal conditions such as overload or short circuit occur in the circuit, the fuse element body 17 will fuse due to the heat generated by the excessive current, thereby cutting off the circuit and playing a protective role. The two circular copper sheets 7 are respectively welded to both ends of the fuse element body 17; in the bimetallic arc-shaped sheet 18, the metal arc-shaped sheet close to the fuse element body 17 is iron-nickel alloy, and the metal arc-shaped sheet far from the fuse element body 17 is metal copper. When the circuit has continuous overload, the bimetallic arc-shaped sheet 18 bends and deforms due to the increase in temperature, applying a lateral pressure to the fuse element body 17, causing microcracks to be generated in the fuse-breaking area in advance, and shortening the fuse-breaking time from 120 ms of the traditional structure to 60 ms, realizing the "pre-trigger" protection of overload.

[0028] In the above scheme, by arranging removable end covers 2 at both ends of the middle hole shell 1, it is convenient to disassemble the shell structure, so as to disassemble and replace the melt body 17. By arranging the bimetallic arc piece 18, when the circuit is continuously overloaded, the bimetallic arc piece 18 is bent by heat, so that microcracks are generated in the fuse zone in advance, reducing the response delay of the fuse, and facilitating the frequent start and stop of the fast charging pile. By arranging the elastic mounting parts, when the electric vehicle is vibrated during charging, the elastic mounting parts buffer and shock the melt body 17, avoid the disconnection between the melt body 17 and the electrode terminal 3, and prevent the contact resistance between the melt body 17 and the electrode terminal 3 from increasing. By arranging the fuse feedback component, when the melt body 17 is melted, the fuse feedback component can be partially extended out of the middle hole shell 1, which is used to prompt and feedback to the maintenance personnel, so that the melt body 17 can be replaced in time to ensure the stable operation of the charging pile.

[0029] In some possible implementations, see Figure 2 and Figure 3 As shown, the melt structure further includes an insulating protective sleeve 6 sleeved on the melt body 17, and the two ends of the insulating protective sleeve 6 are respectively abutted against the inner sides of the two circular copper sheets 7. The outer circumference of the insulating protective sleeve 6 is sleeved with a plurality of heat sinks 11 along its length direction.

[0030] It should be noted that the insulating protective sleeve 6 is made of rubber, and the heat of the melt body 17 is conducted away through the central hole shell 1 by means of a plurality of heat sinks 11, so that the surface temperature of the fuse is ≤80°C.

[0031] In some possible implementations, see Figure 2 , Figure 3 and Figure 5 As shown, two positioning ridges 5 are symmetrically arranged between the two circular copper sheets 7. The positioning ridges 5 are U-shaped structures, and the two ends of the U-shaped structure are respectively connected to the two circular copper sheets 7. The heat sink 11 is located on the inner side of the U-shaped structure. Positioning slots 19 are arranged on the two end surfaces on the inner side of the central hole shell 1. The two positioning ridges 5 are respectively detachably arranged in the two positioning slots 19.

[0032] In the above scheme, by setting the positioning slot 19, the two positioning ridges 5 can be slidably set in the positioning slot 19, so as to position and install the melt structure, and the melt structure is located in the accommodating cavity and has no direct contact with the inner wall of the central hole shell 1, thereby increasing the heat dissipation area of the melt structure and improving the heat dissipation efficiency of the melt structure.

[0033] In some possible implementations, see Figures 1 to 5As shown in the figure, the fuse feedback component includes a metal wire 13 connected to the middle of the fuse body 17. One end of the metal wire 13 away from the fuse body 17 is connected to a trigger pin 14. A sliding-connected connecting plate 15 is sleeved on the trigger pin 14. The four corners of the connecting plate 15 are fixed on the inner wall of the middle-hole housing 1 through columns. A spring 16 is arranged between the inner wall of the middle-hole housing 1 and the connecting plate 15. The spring 16 is sleeved on the trigger pin 14. The two ends of the spring 16 are respectively fixed on the outer wall of the connecting plate 15 and the trigger pin 14. A feedback hole 4 coaxial with the trigger pin 14 is arranged on the middle-hole housing 1. At least part of the upper end of the trigger pin 14 is located in the feedback hole 4.

[0034] In the above solution, under the action of the spring 16, the upper end of the trigger pin 14 is normally located inside the feedback hole 4 and does not protrude from the feedback hole 4. When the fuse body 17 melts, the metal wire 13 will also melt. The spring 16 resets, driving the upper end of the trigger pin 14 to slide upward and protrude outside the feedback hole 4. A red reminder cap for easy observation can be arranged at the upper end of the trigger pin 14, which is convenient for maintenance personnel to judge the operating state of the fuse, so as to facilitate the inspection of the fuse.

[0035] In some possible implementation schemes, Figure 3 And Figure 5 As shown in the figure, a plurality of metal grid pieces 12 are arranged on the inner wall of the middle-hole housing 1 on the side away from the trigger pin 14. The metal grid pieces 12 are thin copper sheets and are installed on the inner wall of the middle-hole housing 1 through insulating brackets. The plurality of metal grid pieces 12 are uniformly arranged along the length direction of the middle-hole housing 1, and the metal grid pieces 12 are arranged obliquely.

[0036] In the above solution, when an arc is generated when the fuse body 17 melts, the arc is sucked into the gaps between the metal grid pieces 12 under the action of the magnetic field (the grid pieces are magnetically conductive by themselves) and is divided into multiple short arcs. By using the "near-cathode effect" and heat dissipation effect of the metal grid pieces 12, the arc is quickly extinguished within 10 ms, and the arc extinguishing efficiency is greatly improved compared with the traditional open structure.

[0037] In some possible implementation schemes, the inner side wall of the insulating protective sleeve 6 is coated with a gas-generating ceramic coating. The main component of the gas-generating ceramic coating is melamine cyanurate, which rapidly decomposes at high temperature to generate inert gases such as N2 and CO2, and the air pressure can reach 0.3 MPa. The inert gases quickly blow out the arc at the initial stage of the arc generation, and cooperate with the metal grid pieces 12 to form a "gas blowing + grid piece" composite arc extinguishing, reducing the energy of the arc and avoiding the arc from burning the internal and external circuits of the middle-hole housing 1.

[0038] In some possible implementation schemes, Figure 2 And Figure 3As shown, the elastic mounting member includes a metal telescopic rod 9. One end of the metal telescopic rod 9 is electrically connected to the corresponding electrode terminal 3. The other end of the metal telescopic rod 9 is provided with a contact copper sheet 8. The contact copper sheet 8 is fixedly connected to the corresponding circular copper sheet 7. A buffer spring 10 is sleeved between the contact copper sheet 8 and the metal telescopic rod 9.

[0039] In the above solution, after the melt structure is installed, the two contact copper sheets 8 are respectively abutted against the two circular copper sheets 7, squeezing the buffer spring 10. Under the action of the elastic force, the contact copper sheet 8 is closely attached to the circular copper sheet 7. When vibration occurs, it buffers and dampens the melt structure, reducing the impact on the melt structure. When disassembling, the melt structure can also be quickly removed for replacement.

[0040] In some possible implementation schemes, Figures 1 to 3 As shown, a ring flange is sleeved on the end of the electrode terminal 3 away from the end cover 2. A plurality of mounting holes are evenly distributed on the ring flange. The ring flange is mounted on the mounting plate of the charging device through countersunk bolts in the mounting holes.

[0041] In some possible implementation schemes, the outer surface of the electrode terminal 3 is treated with silver plating or tin plating to reduce the erosion of the electrode terminal 3 by the environment.

[0042] This specific embodiment is only an explanation of the invention and is not a limitation of the invention. Those skilled in the art can make modifications to this embodiment without creative contributions according to needs after reading this specification, but as long as it is within the protection scope of the invention, it is protected by the patent law.

Claims

1. A safety fuse for an electric vehicle charging facility, characterized in that, Comprising: A housing structure, the housing structure includes a middle-hole housing (1), both ends of the middle-hole housing (1) are provided with detachable end caps (2) to form a receiving cavity, and an electrode terminal (3) is screwed on the end cap (2); A melt structure, the melt structure is detachably installed in the receiving cavity, the melt structure includes a melt body (17), circular copper sheets (7) are fixed at both ends of the melt body (17) in the length direction, a bimetallic arc-shaped sheet (18) is arranged between the two circular copper sheets (7) and is located on one side of the melt body (17), and a fusing feedback component is arranged on the other side of the melt body (17); An elastic mounting member, the elastic mounting member is arranged outside the two circular copper sheets (7), and the outer end of the elastic mounting member is electrically connected to the electrode terminal (3).

2. The safety fuse for an electric vehicle charging facility according to claim 1, characterized in that, The melt structure further includes an insulating protective sleeve (6) sleeved on the melt body (17), and both ends of the insulating protective sleeve (6) are respectively abutted against the inner sides of the two circular copper sheets (7).

3. The safety fuse for an electric vehicle charging facility according to claim 1 or 2, characterized in that, A plurality of heat dissipation fins (11) are sleeved on the outer circumference of the insulating protective sleeve (6) along its length direction.

4. The safety fuse for an electric vehicle charging facility according to claim 3, wherein, Two positioning convex strips (5) are symmetrically arranged between the two circular copper sheets (7), the positioning convex strips (5) are of a U-shaped structure, and both ends of the U-shaped structure are respectively connected to the two circular copper sheets (7), and the heat dissipation fins (11) are located inside the U-shaped structure; Positioning card slots (19) are arranged on the inner side end faces at both ends of the middle-hole housing (1), and the two positioning convex strips (5) are respectively detachably arranged in the two positioning card slots (19).

5. The safety fuse for an electric vehicle charging facility according to claim 3, characterized in that, The fusing feedback component includes a metal wire (13) connected to the middle of the melt body (17); One end of the metal wire (13) departing from the melt body (17) is connected to a trigger pin (14); A sliding-connected connecting plate (15) is sleeved on the trigger pin (14), and the four corners of the connecting plate (15) are fixed on the inner wall of the middle-hole housing (1) through columns; A spring (16) is arranged between the inner wall of the middle-hole housing (1) and the connecting plate (15), the spring (16) is sleeved on the trigger pin (14), and both ends of the spring (16) are respectively fixedly arranged on the outer walls of the connecting plate (15) and the trigger pin (14); A feedback hole (4) coaxial with the trigger pin (14) is arranged on the middle-hole housing (1), and at least part of the upper end of the trigger pin (14) is located in the feedback hole (4).

6. The safety fuse for an electric vehicle charging facility according to claim 5, wherein A plurality of metal grid sheets (12) are arranged on the inner wall of the middle-hole housing (1) on the side departing from the trigger pin (14), the plurality of metal grid sheets (12) are uniformly arranged along the length direction of the middle-hole housing (1), and the metal grid sheets (12) are inclined.

7. The safety fuse for an electric vehicle charging facility according to claim 3, characterized in that, A gas-producing ceramic coating is coated on the inner side wall of the insulating protective sleeve (6).

8. The safety fuse for an electric vehicle charging facility according to claim 4, wherein, The elastic mounting member includes a metal telescopic rod (9), one end of the metal telescopic rod (9) is electrically connected to the corresponding electrode terminal (3), the other end of the metal telescopic rod (9) is provided with a contact copper sheet (8), the contact copper sheet (8) is fixedly connected to the corresponding circular copper sheet (7), and a buffer spring (10) is sleeved between the contact copper sheet (8) and the metal telescopic rod (9).

9. The safety fuse for an electric vehicle charging facility according to claim 8, characterized in that, One end of the electrode terminal (3) facing away from the end cover (2) is sleeved with an annular flange, and a plurality of mounting holes are uniformly distributed on the annular flange. The annular flange is mounted on the mounting plate of the charging device through countersunk bolts and the mounting holes.

10. The safety fuse for an electric vehicle charging facility according to claim 9, characterized in that, The outer surface of the electrode terminal (3) is subjected to silver plating or tin plating treatment.

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