Melt, fuse and surge protector

Abstract

The utility model relates to the field of circuit protection, in particular to a melt, a fuse and application, a plurality of rows of narrow necks are evenly distributed in the length direction of the melt at intervals, the narrow neck located in the middle of the length direction of the melt is a long narrow neck, the narrow necks on the two sides of the long narrow neck are short narrow necks, and the length of the long narrow neck in the length direction of the melt is larger than that of the short narrow necks; the two sides of each narrow neck in the length direction of the melt are respectively provided with a flame-retardant belt, and the flame-retardant belts penetrate through the width of the melt. According to the fuse using the fuse body, a flame-retardant liner is arranged between an inner cap and an outer cap. The fuse body and the fuse can tolerate higher surge current, can tolerate larger voltage, can tolerate larger current, are higher in breaking capacity, can be applied to the rear end of a surge protector, and can meet the requirement that leakage current is broken for backup protection when the surge protector fails.

Description

Technical Field

[0001] The invention belongs to the field of circuit protection, and in particular relates to a fuse used for circuit protection, a fuse made of the fuse, and the use of the fuse. Background Art

[0002] Thermal cutoff fuses generally include a housing, a fuse inserted in the housing, an inner cap at both ends of the housing for fixing the fuse, and an outer cap for connecting the ends. The housing is filled with arc extinguishing medium. A narrow neck is provided on the fuse. When an overload current or a short circuit current occurs in the protected circuit, the fuse melts from the narrow neck to achieve circuit protection.

[0003] The current fuse, such as the one disclosed in Chinese patent CN202223335429.5, has both overload and short circuit protection. The fuse has a long narrow neck in the middle and short narrow necks at both ends, which can achieve both overload and short circuit protection. Although this type of fuse has good overload and short circuit protection performance, its surge resistance performance is poor. Summary of the invention

[0004] The purpose of the patent of this invention is to provide a melt, a fuse and its use. The melt adopts a thick narrow neck, and a combination of a long narrow neck and a short narrow neck, and is combined with a flame retardant tape to enhance the fuse's ability to resist surge impact.

[0005] To achieve the above-mentioned purpose, the technical solution provided by the present invention is a melt, wherein a plurality of rows of narrow necks are evenly spaced along the length direction of the melt, wherein the narrow neck located in the middle position of the length direction of the melt is a long narrow neck, and the narrow necks located on both sides of the long narrow neck are short narrow necks, and the length of the long narrow necks along the length direction of the melt is greater than the length of the short narrow necks; each of the narrow necks is provided with flame retardant belts on both sides along the length direction of the melt, and the flame retardant belts run through the width of the melt.

[0006] Preferably, the flame retardant tape is shared between adjacent narrow necks.

[0007] Preferably, arc-shaped grooves are respectively arranged on both sides of each narrow neck along the length direction of the melt, and the arc-shaped grooves are filled with flame retardants to form the flame retardant belts.

[0008] Preferably, the flame retardant belt structures on both sides of all the narrow necks are the same.

[0009] Preferably, the width of the narrow neck is greater than 0.6 mm.

[0010] A fuse comprises a shell, and an inner cap and an outer cap located at two ends of the shell, wherein the above-mentioned fuse is inserted into the shell, and the two ends of the fuse are respectively conductively connected to the inner cap, the outer cap is located at the outer periphery of the inner cap and is in conductive contact with the inner cap, and the fuse is filled with an arc extinguishing medium.

[0011] Preferably, a flame retardant gasket is provided between the inner cap and the outer cap in the radial direction of the shell.

[0012] Preferably, an indicator is provided at one end of the shell, and one end of the indicator passes through the outer cap, the flame retardant liner and the inner cap and is located in the shell, and the conductor on the indicator passes through the inside of the shell and is conductively connected to the outer cap at the other end of the shell.

[0013] Preferably, the outer peripheral sleeve of the indicator located in the housing is provided with a flame retardant indicator sleeve.

[0014] Preferably, the outer cap through which the indicator passes extends into the shell to form a matching tube wall, the matching tube wall passes through the inner cap, the indicator is interference fit with the matching tube wall of the outer cap, the flame-retardant indicator sleeve is connected to the end face of the matching tube wall of the outer cap located in the shell, and the flame-retardant gasket is sleeved on the outer periphery of the matching tube wall of the outer cap.

[0015] Preferably, the shell is made of melamine.

[0016] Preferably, a pin sheet is conductively connected to the outer end surface of the outer cap, and when an indicator is provided at the end of the shell, the indicator passes through the pin sheet.

[0017] Preferably, a solder resist is provided on the surface of the pin piece to prevent the solder from flowing toward the outer cap.

[0018] Preferably, the pin piece is arranged perpendicular to the length direction of the shell.

[0019] The above-mentioned fuse is applied to the rear end of the surge protector as a backup protection. When the surge protector is an integrated structure, the fuse is built into the integrated surge protector as a backup protection.

[0020] The fuse of the present invention is made of copper and has a thick and narrow neck, so that the fuse can withstand a higher surge current In40kA;

[0021] The fuse has a long narrow neck in the middle. The resistance value at the long narrow neck is higher and the fusing speed is faster, which can make the fuse break a smaller current of 160A or 240A. Multiple rows of narrow necks are evenly arranged along the length of the fuse, and flame retardant strips are set on both sides of each narrow neck, which can make the fuse withstand a higher voltage of AC1250V or DC1500V.

[0022] Adding flame-retardant pads to the fuse, and adding flame-retardant indicator sleeves when indicators are provided, can block arc ejection and enable the fuse to withstand greater currents;

[0023] The shell is made of melamine material, which has excellent flame retardant and heat-resistant properties, making the fuse breaking capacity stronger, and the maximum breaking current can reach 100KA.

[0024] The fuse has additional welded pins at both ends, and no base is required, so it can be directly soldered to the inner box of the integrated surge protector.

[0025] Adding solder mask on the pin surface can block the flow of solder during welding, and the tin plating of the rest of the pin surface after welding has no effect;

[0026] The indicator is built-in, and the indicator end has no protrusion relative to the pin sheet. The overall size is φ22.2×87, which can save space.

[0027] The fuse of the present invention can be used in a surge protector, and when provided with a pin sheet, can be used in an integrated surge protector.

[0028] The fuse is designed to resist surges and can withstand higher surge currents, greater voltages, greater currents, and stronger breaking capacity. It is used as the back end of a surge protector to break leakage current as backup protection when the surge protector fails; it meets the built-in requirements of an integrated surge protector. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the three-dimensional structure of the melt.

[0030] Figure 2 It is a schematic diagram of the side view structure of the melt.

[0031] Figure 3 It is a schematic diagram of the front structure of the melt.

[0032] Figure 4 It is a schematic diagram of the three-dimensional structure of the fuse.

[0033] Figure 5 It is a schematic diagram of the fuse's appearance end structure when viewed from the front.

[0034] Figure 6 It is a schematic diagram of the cross-sectional structure of the fuse. DETAILED DESCRIPTION

[0035] With respect to the above technical solution, preferred embodiments are now cited and specifically described in conjunction with drawings.

[0036] See also Figures 1 to 3The melt 1 of the present invention is made of copper. Several narrow necks are arranged at intervals along the length direction of the melt 1. The narrow neck in the middle of the length direction of the melt 1 is a long narrow neck 11, and several short narrow necks 12 are evenly distributed on the melt 1 on both sides of the long narrow neck 11. The length of the long narrow neck 11 along the length direction of the melt is greater than the length of the short narrow neck 12. The width of the long narrow neck 11 and the short narrow neck 12 along the width direction of the melt 1 is preferably greater than 0.6 mm, which is a thick narrow neck.

[0037] Arc-shaped grooves 13 are respectively provided on both sides of each narrow neck along the length direction of the melt 1, and one arc-shaped groove 13 is shared between two adjacent narrow necks. Both ends of the arc-shaped groove 13 pass through the width of the melt 1. The arc-shaped groove 13 is filled with flame retardant to form a flame retardant belt 14, which passes through the width of the melt 1. The flame retardant belt 14 isolates the arc generated when two adjacent narrow necks are melted.

[0038] See also Figures 4 to 6 The fuse of the present invention comprises a housing 2, a fuse 1, an inner cap 3, an outer cap 4, an indicator 5, and a pin sheet 6, wherein:

[0039] The housing 2 is a tubular structure with two ends connected, and is made of melamine, which has excellent flame retardancy and heat resistance, and can improve the breaking capacity of the fuse. In this embodiment, the housing 2 is a round tube structure.

[0040] An inner cap 3 and an outer cap 4 are arranged at the two ends of the shell 2 in sequence. The outer cap 4 is located at the outer periphery of the inner cap, and the outer cap 4 is in conductive contact with the inner cap 3. The inner cap and the outer cap are connected to the shell by interference fit. The melt 1 is inserted into the shell 2, and the two ends of the melt 1 are conductively connected to the inner caps located at the two ends of the shell 2. The connection between the melt 1 and the inner cap 3 is connected by welding.

[0041] The end surfaces of the outer cap 4 and the inner cap 3 in the radial direction of the housing 2 are provided with through holes for the indicator 5 to pass through. The periphery of the through hole of the outer cap 4 for the indicator 5 to pass through extends toward the inside of the housing 1 to form an annular matching cylinder wall 41, and the matching cylinder wall 41 of the outer cap passes through the through hole of the inner cap 3. A flame retardant gasket 7 is provided between the inner cap 3 and the outer cap 4 in the radial direction of the housing 2. When the matching cylinder wall 41 on the outer cap passes through the through hole of the inner cap 3, it also passes through the flame retardant gasket 7.

[0042] The indicator 5 is located at one end of the fuse. One end of the indicator 5 passes through the matching cylinder wall 41 of the outer cap 4 in an interference fit manner and extends into the interior of the housing 2, and the other end of the indicator 5 is located outside the outer cap 4. The outer periphery of the indicator 5 located inside the housing 2 and outside the matching cylinder wall 41 of the outer cap 4 is sleeved with a flame-retardant indicator sleeve 51, and the end surface of the flame-retardant indicator sleeve 51 is butted against the end surface of the matching cylinder wall 41 of the outer cap 4 located inside the housing 2 to form a closure for the portion of the indicator 5 located inside the housing 2. By the cooperation of the flame-retardant indicator sleeve 51 and the flame-retardant gasket 7, the arc is blocked from spraying out of the housing 2, so that the fuse can withstand a larger current.

[0043] The indicator 5 mainly includes an indicator housing, in which a spring is arranged. One end of the spring located at the outer end of the housing is placed at the inner fixing cap. A red warning cap is arranged outside the inner fixing cap, or a conductive contact is connected. In this embodiment, a red cap is used. One end of the conductor 52 is fixedly connected to the inner fixing cap, and the other end passes through the indicator housing and the flame-retardant indicator sleeve 51, the interior of the housing 2, and then is conductively connected and fixed to the inner cap at the other end of the housing 2 ( Figure 6 Only a part of the conductor is shown in the figure). The inner fixing cap is bounded by the conductor to compress the spring so that the spring is in a compressed state. At this time, the red cap is located in the indicator housing. The conductor 52 is made of constantan wire. When the fuse blows, the conductor blows, and the spring of the indicator loses its binding force, and then pops outward under the action of the elastic force, so that the red cap of the indicator extends out of the fuse, reminding the operator that the circuit is faulty and needs to be repaired in time. Alternatively, when a conductive contact is connected, the conductive contact that pops outward is connected to an external alarm trigger circuit, and an alarm signal is sent to the outside through the alarm trigger circuit, reminding the operator to repair the circuit.

[0044] The pin piece 6 is a sheet structure made of a conductive material. The outer end surfaces of the outer caps 4 at both ends of the housing 2 are respectively fixedly welded with the pin pieces 6, and the pin pieces 6 are conductively connected to the outer caps 4. The pin piece 6 is arranged with an axis perpendicular to the length direction of the housing 2 to facilitate the connection of the fuse with other components in a plug-in manner. For example, in an integrated surge protector, the pin piece of the fuse can be arranged in the surge protector in a plug-in manner.

[0045] A through hole for the indicator 5 to pass through is formed in the pin sheet 6 , and one end of the indicator 5 located outside the outer cap 4 is located in the through hole of the pin sheet 5 .

[0046] The surface of the pin piece 6 is tin-plated. When the pin piece is welded, the high temperature of welding may cause the tin-plated layer on the surface of the pin piece to melt, resulting in a poor appearance. Therefore, solder resist tapes 61 are provided on both surfaces of the pin piece 6, and the solder resist tapes 61 run through the width of the pin piece. The solder resist tapes 61 are directly connected to the base material of the pin piece. During welding, the solder resist tapes prevent the melted tin liquid on the surface of the tin-plated layer at the welding connection end of the pin piece 6 from flowing toward the side of the outer cap 4, thereby improving the appearance quality of the fuse.

[0047] In the above embodiment, an indicator is provided at one end of the fuse. In other embodiments, the indicator may not be provided. When the indicator is not provided, the end face of the outer cap 4 is closed, and the pin sheet 6 does not need to have a through hole for the indicator to pass through.

[0048] In other embodiments, the pin sheet 6 may not be used.

[0049] The advantage of using a pin sheet on a fuse is that it is easy to connect to external components. For example, when used in an integrated surge protector, by welding the pin sheet to the surge protector, the fuse is located in the housing of the surge protector, forming a built-in fuse, reducing the size of the surge protector and avoiding the use of a base.

[0050] The fuse of the present invention can withstand higher surge current, higher voltage, higher current and stronger breaking capacity. It can be used at the rear end of a surge protector and connected in series with the surge protector as backup protection for the surge protector. When the surge protector is an integrated structure, the fuse is built into the integrated surge protector as backup protection.

Claims

1. A melt, characterized in that: Several rows of narrow necks are evenly spaced along the length direction of the melt, wherein the narrow neck located in the middle position of the length direction of the melt is a long narrow neck, and the narrow necks located on both sides of the long narrow neck are short narrow necks, and the length of the long narrow necks along the length direction of the melt is greater than the length of the short narrow necks; each of the narrow necks is provided with flame retardant belts on both sides along the length direction of the melt, and the flame retardant belts run through the width of the melt.

2. The melt according to claim 1, characterized in that The flame retardant tape is shared between adjacent narrow necks.

3. The melt according to claim 2, characterized in that Arc-shaped grooves are respectively arranged on both sides of each narrow neck along the length direction of the melt, and the arc-shaped grooves are filled with flame retardants to form the flame retardant belts.

4. The melt according to claim 3, characterized in that The flame retardant belt structures on both sides of all the narrow necks are the same.

5. The melt according to any one of claims 1 to 4, characterized in that The width of the narrow neck is greater than 0.6 mm.

6. A fuse, characterized in that: It comprises a shell, and an inner cap and an outer cap located at two ends of the shell, wherein the fuse according to any one of claims 1 to 5 is passed through the shell, and the two ends of the fuse are respectively conductively connected to the inner cap, the outer cap is located at the outer periphery of the inner cap and is in conductive contact with the inner cap, and the fuse is filled with an arc extinguishing medium.

7. The fuse according to claim 6, characterized in that: A flame retardant gasket is arranged between the inner cap and the outer cap in the radial direction of the shell.

8. The fuse according to claim 7, characterized in that: An indicator is arranged at one end of the shell, and the one end of the indicator passes through the outer cap, the flame retardant liner and the inner cap and is located in the shell. The conductor on the indicator passes through the inside of the shell and is conductively connected to the outer cap at the other end of the shell.

9. The fuse according to claim 8, characterized in that: The outer peripheral sleeve of the indicator located in the housing is provided with a flame retardant indicator sleeve.

10. The fuse according to claim 9, characterized in that: The outer cap through which the indicator passes extends into the shell to form a matching tube wall, the matching tube wall passes through the inner cap, the indicator is interference fit with the matching tube wall of the outer cap, the flame-retardant indicator sleeve is connected to the end face of the matching tube wall of the outer cap located in the shell, and the flame-retardant gasket is sleeved on the outer periphery of the matching tube wall of the outer cap.

11. The fuse according to any one of claims 6 to 10, characterized in that: A pin sheet is conductively connected to the outer end surface of the outer cap. When an indicator is provided at the end of the shell, the indicator passes through the pin sheet.

12. The fuse according to claim 11, characterized in that A solder resist is arranged on the surface of the pin piece to prevent the solder from flowing toward the outer cap.

13. The fuse according to claim 11, characterized in that: The pin piece is arranged perpendicular to the length direction of the shell.

14. A surge protector, characterized in that: The fuse described in any one of claims 6 to 13 is connected in series with the surge protector. When the fuse and the surge protector are an integrated structure, the fuse is arranged in the housing of the surge protector.

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