Fuse and surge protector backup protection device

Abstract

The utility model relates to the field of surge protector equipment, in particular to a fuse and surge protector backup protection equipment. The fuse provided by the utility model is used for backup protection of a surge protector, and comprises a heating element and a fusing element, the fusing element is used for being connected with the surge protector in series, the heating element is matched with the fusing element, the heating element is used for being connected with the surge protector in parallel, and the heating element is electrified to generate heat to fuse the fusing element. In this way, the lightning protection circuit where the surge protector is located is disconnected. The impact current resistance of the fuse can be improved.

Description

Technical Field

[0001] The utility model relates to the field of surge protector equipment, in particular to a fuse and a surge protector backup protection device. Background Art

[0002] The function of the surge protector body is to protect the line it is connected to. The surge protector body is used in electrical circuits or communication lines. Its principle is to conduct and shunt the impact current through the internal varistor, thereby preventing the impact current from damaging the equipment on the electrical circuit or communication line. The varistor may deteriorate after long-term use. In the traditional solution, a thermal trip component is provided in the surge protector body used in the electrical circuit. When the varistor deteriorates and the surge protector body is subjected to a continuous small current impact, the thermal trip component can disconnect the connection between the line and the ground wire by melting, thereby achieving the purpose of thermal tripping; and for the power frequency current, the surge protector body is protected by connecting it in series with the fuse. Specifically, when the power frequency current flows through the fuse, the circuit in the fuse is disconnected, thereby preventing the heat generated by the power frequency circuit from causing the surge protector body to burn. The defect of the above scheme is that the surge protector body is connected in series with the fuse. When the power frequency current flows through it, the current flowing through the fuse is small due to the large resistance of the varistor of the surge protector body. In order to make the fuse blow, a model with a smaller rated current is required. When the impact current flows through the surge protector body, it will inevitably flow through the fuse, which may cause the circuit in the fuse with a smaller rated current to be disconnected. Therefore, the fuse in the above scheme has poor impact current resistance. Utility Model Content

[0003] On the one hand, the utility model provides a fuse, which can improve the ability of the fuse to withstand impact current.

[0004] On the other hand, the utility model provides a surge protector backup protection device.

[0005] The fuse provided by the utility model is used for backup protection of a surge protector, and comprises a heating element and a fuse. The fuse is used to be connected in series with the surge protector, and the heating element cooperates with the fuse. The heating element is used to be connected in parallel with the surge protector, and when powered on, heat is generated to melt the fuse, so that the lightning protection circuit where the surge protector is located is disconnected.

[0006] Furthermore, the heating element is an electric heating wire, the fuse element includes a conductive sheet, the conductive sheet has a certain melting point, and the electric heating wire is insulated from the conductive sheet.

[0007] Furthermore, the electric heating wire is a spring structure, the conductive sheet is a tubular structure having a first lumen, the electric heating wire is located in the first lumen, and an inner insulating layer is provided between the lumen wall of the first lumen and the electric heating wire.

[0008] Furthermore, the fuse also includes a thermal insulation tube, which is located in the first tube cavity, and the electric heating wire is wound on the outer wall surface of the thermal insulation tube.

[0009] Furthermore, the fuse also includes an outer insulating tube, which has a second tube cavity, and the electric heating wire and the conductive sheet are both arranged in the second tube cavity. The openings at both ends of the second tube cavity are respectively provided with fuse caps for sealing. The fuse cap is fixedly matched with the conductive sheet, and the fuse cap is also used to be electrically connected to the lightning protection circuit.

[0010] Furthermore, a connecting piece is provided at the position of the fuse cap corresponding to the second tube cavity, one end of the connecting piece is fixedly matched with the inner wall surface of the fuse cap, and the other end is crimped with the conductive piece.

[0011] Furthermore, the fuse also includes an outer insulating tube, the insulating tube has a second tube cavity, the conductive sheet is arranged in the second tube cavity, and the openings at both ends of the second tube cavity are respectively provided with fuse caps for sealing, the fuse cap is fixedly matched with the conductive sheet, and the fuse cap is also used to be electrically connected to the lightning protection circuit.

[0012] Furthermore, a connecting tube is provided at the fuse cap corresponding to the second tube cavity, one end of the connecting tube is fixedly matched with the inner wall surface of the fuse cap, and the other end is sleeved on the outer wall surface of the tubular structure formed by the conductive sheet and crimped with the conductive sheet.

[0013] Furthermore, a dissolution-promoting layer is provided between the outer wall surface of the tubular structure formed by the conductive sheet and the inner wall surface of the outer insulating tube.

[0014] The backup protection device of the surge protector provided by the utility model comprises the fuse as described in any one of the above items.

[0015] Beneficial Effects

[0016] The fuse in this solution is arranged in series on the lightning protection circuit where the surge protector is located, the heating element is arranged on the control circuit in parallel with the surge protector and the fuse, and a switch is arranged on the control circuit. The switch can control the connection or disconnection of the control circuit according to the current size on the lightning protection circuit where the surge protector is located. When the power frequency current flows through the lightning protection circuit where the surge protector is located, the switch is closed according to the preset triggering condition to connect the control circuit. At this time, most of the current bypasses the surge protector through the control circuit, and the power frequency current flows through the control circuit through the heating element. The heat generated by the heating element melts the fuse. Compared with the traditional solution where the power frequency current directly flows to the fuse through the surge protector, and the fuse wire in the fuse melts due to self-heating, the fuse in this solution has only the fuse connected in series to the circuit where the surge protector is located. The heating element is heated by the power frequency current that does not pass through the surge protector and melts the fuse. Since the power frequency current does not pass through the surge protector, the current value of the power frequency current is relatively large. Therefore, a fuse with a larger rated current can be selected to avoid the impact current from disconnecting the circuit in the fuse. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 It is an overall schematic diagram provided by the first embodiment of the utility model;

[0019] Figure 2 It is a structural schematic diagram provided by the second embodiment of the present utility model;

[0020] Figure 3 This is a circuit diagram provided by Embodiment 3 of the present utility model.

[0021] Figure numbers: 1-fuse; 2-heating element; 3-surge protector; 4-electric heating wire; 5-conductive sheet; 6-insulating tube; 7-fusible core cap; 8-outer insulating tube; 9-connecting tube; 10-dissolving layer; 11-inner insulating layer; 12-lightning protection circuit; 13-current transformer; 14-switch element; 15-electromagnetic element; 16-control circuit. DETAILED DESCRIPTION

[0022] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0023] Embodiment 1

[0024] A fuse includes a heating element 2 and a fuse 1, wherein the fuse 1 is used to be connected in series with a surge protector 3, the heating element 2 cooperates with the fuse 1, the heating element 2 is used to be connected in parallel with the surge protector 3, and the fuse 1 is melted by generating heat when powered on, so that the lightning protection circuit 12 where the surge protector 3 is located is disconnected.

[0025] The function of the surge protector body is to protect the line it is connected to. The surge protector body is used in electrical circuits or communication lines. Its principle is to conduct and shunt the impact current through the internal varistor, thereby preventing the impact current from damaging the equipment on the electrical circuit or communication line. The varistor may deteriorate after long-term use. In the traditional solution, a thermal trip component is provided in the surge protector body used in the electrical circuit. When the varistor deteriorates and the surge protector body is subjected to a continuous small current impact, the thermal trip component can disconnect the connection between the line and the ground wire by melting, thereby achieving the purpose of thermal tripping; and for the power frequency current, the surge protector body is protected by connecting it in series with the fuse. Specifically, when the power frequency current flows through the fuse, the circuit in the fuse is disconnected, thereby preventing the heat generated by the power frequency circuit from causing the surge protector body to burn. The defect of the above scheme is that the surge protector body is connected in series with the fuse. When the power frequency current flows through it, the current flowing through the fuse is small due to the large resistance of the varistor of the surge protector body. In order to make the fuse blow, a model with a smaller rated current is required. When the impact current flows through the surge protector body, it will inevitably flow through the fuse, which may cause the circuit in the fuse with a smaller rated current to be disconnected. Therefore, the fuse in the above scheme has poor impact current resistance. Compared with the above scheme, the fuse 1 in this scheme is arranged in series on the lightning protection circuit 12 where the surge protector 3 is located, the heating element 2 is arranged on the control circuit 16 in parallel with the surge protector 3 and the fuse 1, and the control circuit 16 is provided with a switch 14, which can control the connection or disconnection of the control circuit 16 according to the current size on the lightning protection circuit 12 where the surge protector 3 is located. When there is a power frequency current flowing through the lightning protection circuit 12 where the surge protector 3 is located, the switch 14 is closed according to the preset trigger condition to connect the control circuit 16. At this time, most of the current bypasses the surge protector 3 through the control circuit 16, and the power frequency The current flows through the heating element 2 through the control loop 16, and the heat generated by the heating element 2 melts the fuse 1. Compared with the traditional solution, the power frequency current directly flows to the fuse through the surge protector 3, and the fuse in the fuse melts due to self-heating. In the fuse of this solution, only the fuse 1 is connected in series to the circuit where the surge protector 3 is located. The heating element 2 is heated by the power frequency current that does not pass through the surge protector 3, and melts the fuse 1. Since the power frequency current does not pass through the surge protector 3, the current value of the power frequency current is relatively large. Therefore, a fuse 1 with a larger rated current can be selected to avoid the impact current from disconnecting the circuit in the fuse.

[0026] In an optional embodiment, the heating element 2 is an electric heating wire 4, the fuse element 1 includes a conductive sheet 5, the conductive sheet 5 has a certain melting point, and the electric heating wire 4 and the conductive sheet 5 are insulated and matched.

[0027] The two ends of the conductive sheet 5 are respectively connected to the lightning protection circuit 12 where the surge protector 3 is located. Preferably, the conductive sheet 5 is connected in series to the circuit on the grounded side of the surge protector 3. One end of the electric heating wire 4 is connected to the circuit on the side of the surge protector 3 connected to the power line, and the other end is grounded. When the power frequency current passes through the electric heating wire 4, the electric heating wire 4 generates heat and transfers it to the conductive sheet 5. When the conductive sheet 5 reaches the melting point, the part between the two ends of the conductive sheet 5 connected to the lightning protection circuit 12 is melted, thereby disconnecting the lightning protection circuit 12.

[0028] The conductive sheet 5 is connected in series to the lightning protection circuit 12 where the surge protector 3 is located. When the impact current passes through the surge protector 3, it finally flows into the ground through the conductive sheet 5. In order to prevent the impact current flowing through the conductive sheet 5 from melting the electric heating wire 4 or causing the electric heating wire 4 to overheat, an insulating structure is provided between the electric heating wire 4 and the conductive sheet 5 in this solution, and the insulating structure can transfer heat.

[0029] In an optional embodiment, the fuse also includes an outer insulating tube 8, the insulating tube has a second tube cavity, the electric heating wire 4 and the conductive sheet 5 are both arranged in the second tube cavity, and the openings at both ends of the second tube cavity are respectively provided with a fuse cap 7 for sealing, the fuse cap 7 is fixedly matched with the conductive sheet 5, and the fuse cap 7 is also used to be electrically connected to the lightning protection circuit 12.

[0030] The function of the outer insulating tube 8 is to support and protect the conductive sheet 5 and the electric heating wire 4 in the second tube cavity. The outer insulating tube 8 is made of ceramic material, and the two ends of the outer insulating tube 8 are respectively sleeved with fuse caps 7, which block the two end openings of the second tube cavity, and fix the conductive sheet 5 through connecting pieces. Specifically, a connecting piece is provided on the inner wall of each fuse cap 7, one end of the connecting piece is welded to the fuse cap 7, and the other end is welded to the conductive sheet 5, and the two ends of the conductive sheet 5 correspond to the connecting pieces respectively, so that the conductive sheet 5 is fixed in the second tube cavity.

[0031] The electric heating wire 4 passes through the outer insulating tube 8 and is fixed to the wall of the outer insulating tube 8. The fuse cap 7 and the connecting piece are made of conductive material. When the impulse current passes through the fuse, it passes through the fuse cap 7 and the connecting piece at one end, passes through the conductive piece 5, and finally passes through the connecting piece and the fuse cap 7 at the other end.

[0032] In an optional embodiment, a connecting piece is provided at the fuse cap 7 corresponding to the second tube cavity, one end of the connecting piece is fixedly matched with the inner wall surface of the fuse cap 7 , and the other end is crimped with the conductive piece 5 .

[0033] Embodiment 2

[0034] In an optional embodiment, the electric heating wire 4 is a spring structure, the conductive sheet 5 is a tubular structure having a first lumen, the electric heating wire 4 is located in the first lumen, and an inner insulating layer 11 is provided between the lumen wall of the first lumen and the electric heating wire 4 .

[0035] The conductive sheet 5 is a tubular structure with a first lumen inside. The electric heating wire 4 is located in the first lumen. The electric heating wire 4 in this solution is wound to form a spring. Under the premise that the length along the radial direction of the first lumen is constant, the actual length of the electric heating wire 4 in the first lumen is increased, and the heating value is increased. Therefore, a fuse 1 with a larger rated current can be selected to avoid the impact current from disconnecting the circuit in the fuse.

[0036] Both ends of the first tube cavity are opened respectively to facilitate the electric heating wire 4 to pass through. The inner insulating layer 11 is laid on the inner wall of the first tube cavity to separate the electric heating wire 4 from the conductive sheet 5.

[0037] In an optional embodiment, the fuse further includes a thermal insulation tube 6 , the thermal insulation tube 6 is located in the first tube cavity, and the electric heating wire 4 is wound around the outer wall surface of the thermal insulation tube 6 .

[0038] The heat-insulating tube 6 is made of heat-insulating cotton material and is used to support the electric heating wire 4 so that the electric heating wire 4 maintains a spring structure and prevents the heat generated by the electric heating wire 4 from accumulating in the spring structure.

[0039] In an optional embodiment, the fuse also includes an outer insulating tube 8, the insulating tube has a second tube cavity, the conductive sheet 5 is arranged in the second tube cavity, and the openings at both ends of the second tube cavity are respectively provided with fuse caps 7 for sealing, the fuse cap 7 is fixedly matched with the conductive sheet 5, and the fuse cap 7 is also used to be electrically connected to the lightning protection circuit 12.

[0040] The function of the outer insulating tube 8 is to support and protect the conductive sheet 5 and the electric heating wire 4 in the second tube cavity. The outer insulating tube 8 is made of ceramic material, and the two ends are respectively sleeved with fuse caps 7, which block the two end openings of the second tube cavity, and fix the conductive sheet 5 through the connecting tube 9. Specifically, a connecting tube 9 is provided on the inner wall of each fuse cap 7, one end of the connecting tube 9 is welded on the fuse cap 7, and the other end is sleeved on the two ends of the tubular structure of the conductive sheet 5. The two ends of the conductive sheet 5 correspond to the connecting tube 9 respectively, so that the conductive sheet 5 is fixed in the second tube cavity.

[0041] The electric heating wire 4 is located in the first tube cavity of the conductive sheet 5 , with both ends passing through the openings at both ends of the first tube cavity, and passing through the outer insulating tube 8 , and being fixed to the wall of the outer insulating tube 8 .

[0042] Preferably, the electric heating wire 4 passes through the fuse cap 7 and is insulated from the fuse cap 7 .

[0043] In an optional embodiment, a connecting tube 9 is provided at the fuse cap 7 corresponding to the second tube cavity, one end of the connecting tube 9 is fixedly matched with the inner wall surface of the fuse cap 7, and the other end is sleeved on the outer wall surface of the tubular structure formed by the conductive sheet 5 and crimped with the conductive sheet 5.

[0044] In an optional embodiment, a dissolution-promoting layer 10 is provided between the outer wall surface of the tubular structure formed by the conductive sheet 5 and the inner wall surface of the outer insulating tube 8 .

[0045] The electric heating wire 4 heats up rapidly to melt the outer layer of low melting point metal, namely the conductive sheet 5 . The conductive sheet 5 is filled with a flux outside to melt the conductive sheet 5 rapidly and condense into low temperature metal beads, thereby disconnecting the circuit where the surge protector 3 is located.

[0046] Embodiment 3

[0047] The backup protection device of the surge protector provided by the utility model comprises a fuse as in any of the above embodiments.

[0048] The surge protector 3 is arranged on the lightning protection circuit 12, the fuse element 1 of the fuse is arranged in series with the surge protector 3 on the lightning protection circuit 12 to form a fuse circuit, the control loop 16 is arranged in parallel with the fuse circuit, and the control loop 16 is provided with a switch element 14 and a heating element 2 of the fuse in series. The switch element 14 can control the connection or disconnection of the control loop 16 according to the current size on the lightning protection circuit 12 where the surge protector 3 is located.

[0049] When an industrial frequency current flows through the lightning protection circuit 12 where the surge protector 3 is located, the switch 14 is closed according to the preset trigger condition to connect the control loop 16. At this time, most of the current bypasses the surge protector 3 through the control loop 16, so that the industrial frequency current flows through the heating element 2. The heating element 2 generates heat that is transferred to the fuse 1, and the fuse 1 melts, and the lightning protection circuit 12 where the surge protector 3 is located is disconnected.

[0050] In an optional implementation, a current transformer 13 is provided on the lightning protection circuit 12 where the surge protector 3 is located, and an output end of the current transformer 13 is electrically connected to an electromagnetic component 15 , and the electromagnetic component 15 can be linked with the switch component 14 .

[0051] When a large overcurrent appears on the lightning protection circuit 12 where the surge protector 3 is located, the output of the through-core current transformer 13 drives the electromagnetic component 15 to operate, and the electromagnetic component 15 and the switch component 14 are linked to form an electromagnetic release. The switch component 14 is attracted under the action of the electromagnetic component 15, and the control circuit 16 is connected. The current on the lightning protection circuit 12 where the surge protector 3 is located flows to the control circuit 16 through the control circuit 16 and the contacts on the lightning protection circuit 12 where the surge protector 3 is located, and then flows to the lightning protection circuit 12 on the grounding side of the surge protector 3 through the contacts on the other side, or is directly grounded, thereby avoiding the influence of the varistor in the surge protector 3 on the rated current value of the fuse 1.

[0052] It should be noted that any of the above embodiments is illustrative of the present invention rather than limiting the present invention, and that those skilled in the art may design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbol between brackets should not be constructed as a limitation on the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "one" or "an" preceding an element does not exclude the presence of multiple such elements. The present invention may be implemented by means of hardware comprising several different elements and by means of appropriately programmed computers. In a unit claim that lists several devices, several of these devices may be embodied by the same hardware item. The use of the words primary, secondary, previous, and next, etc. does not indicate any order. These words may be interpreted as names.

[0053] The above implementation modes are only suitable for illustrating the present invention, but not for limiting the present invention. Ordinary technicians in the relevant technical field can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions also belong to the scope of the present invention. The scope of patent protection of the present invention should be limited by the claims.

Claims

1. A fuse for backup protection of a surge protector (3), characterized in that: The device comprises a heating element (2) and a fuse (1), wherein the fuse (1) is used to be connected in series with a surge protector (3), the heating element (2) cooperates with the fuse (1), the heating element (2) is used to be connected in parallel with the surge protector (3), and when powered on, generates heat to melt the fuse (1), thereby disconnecting a lightning protection circuit (12) where the surge protector (3) is located; The heating element (2) is an electric heating wire (4), the fuse (1) comprises a conductive sheet (5), the conductive sheet (5) has a certain melting point, and the electric heating wire (4) is insulated from the conductive sheet (5); The electric heating wire (4) is a spring structure, the conductive sheet (5) is a tubular structure having a first lumen, the electric heating wire (4) is located in the first lumen, and an inner insulating layer (11) is provided between the lumen wall of the first lumen and the electric heating wire (4); The fuse also includes an outer insulating tube (8), the insulating tube having a second tube cavity, the electric heating wire (4) and the conductive sheet (5) are both arranged in the second tube cavity, and fuse caps (7) for blocking are respectively provided at the openings at both ends of the second tube cavity, the fuse cap (7) is fixedly matched with the conductive sheet (5), and the fuse cap (7) is also used to be electrically connected to the lightning protection circuit (12).

2. The fuse according to claim 1, characterized in that: The fuse further comprises a heat-insulating tube (6), the heat-insulating tube (6) being located in the first tube cavity, and the electric heating wire (4) being wound around the outer wall surface of the heat-insulating tube (6).

3. The fuse according to claim 1, characterized in that: The fuse cap (7) is provided with a connecting piece at a position corresponding to the second tube cavity, one end of the connecting piece is fixedly matched with the inner wall surface of the fuse cap (7), and the other end is crimped with the conductive piece (5).

4. The fuse according to claim 1, characterized in that: The fuse cap (7) is provided with a connecting tube (9) at a position corresponding to the second tube cavity, one end of the connecting tube (9) is fixedly matched with the inner wall surface of the fuse cap (7), and the other end is sleeved on the outer wall surface of the tubular structure formed by the conductive sheet (5) and crimped with the conductive sheet (5).

5. The fuse according to claim 1, characterized in that: A dissolution-promoting layer (10) is provided between the outer wall surface of the tubular structure formed by the conductive sheet (5) and the inner wall surface of the outer insulating tube (8).

6. A surge protector backup protection device, characterized in that: Comprising the fuse as described in any one of claims 1-5.

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