CN114284118B

CN114284118B - Fuse for power distribution system

Info

Publication number: CN114284118B
Application number: CN202111628990.XA
Authority: CN
Inventors: 魏松泽
Original assignee: Xuzhou Hantong Electronic Technology Co ltd
Current assignee: Xuzhou Hantong Electronic Technology Co ltd
Priority date: 2021-12-28
Filing date: 2021-12-28
Publication date: 2022-10-04
Anticipated expiration: 2041-12-28
Also published as: CN114284118A

Abstract

The invention relates to the technical field of electrical equipment, and discloses a fuse for a power distribution system, which comprises a porcelain bushing, wherein the top end of the porcelain bushing is fixedly connected with an upper fixed seat, an inlet line is arranged in the upper fixed seat, the side wall of one side below the porcelain bushing is fixedly connected with a lower fixed seat, an outlet line is arranged in the lower fixed seat, and the bottom end of the upper fixed seat, which is positioned in the upper fixed seat, is fixedly connected with an upper contact seat. The fuse tube is divided into the upper fuse tube and the lower fuse tube, the upper fuse tube and the lower fuse tube are movably sleeved with the arc extinguishing tube, one end of the upper fuse tube is fixedly connected with the upper conductive block, one end of the lower fuse tube is fixedly connected with the lower conductive block, the fuse wire penetrates through the upper conductive block, the upper fuse tube, the lower fuse tube and the lower conductive block and is fixed by the fixing ball, so that the fuse wire is simply and quickly installed in the arc extinguishing tube, time and labor are saved, meanwhile, the installation process of the fuse wire is always kept in a linear state, the fuse wire is effectively protected from being bent and rubbed, and the integrity and functionality of the fuse wire are enhanced.

Description

Fuse for power distribution system

Technical Field

The invention relates to the technical field of electrical equipment, in particular to a fuse for a power distribution system.

Background

The fuse is an electric appliance which fuses a melt by heat generated by the fuse when the current exceeds a specified value and breaks a circuit, and the fuse is widely applied to high-low voltage distribution systems, control systems and electric equipment, is used as a short-circuit and overcurrent protector and is one of the most commonly applied protective devices.

The existing market discloses a full-insulation injection type fuse, which comprises a fuse tube, wherein the middle part of the fuse tube is a hollow cavity, a fuse wire is arranged in the hollow cavity, the fuse wire is distributed and connected with an inlet wire and an outlet wire through an upper contact seat and a lower contact seat, the fuse wire is fused by itself to form an electric arc, then special materials in the arc extinguishing tube are gasified to generate a large amount of gas under the high-temperature action of the electric arc, then the electric arc is blown out by relying on the gas when the current passes zero, and a shedding part in the ceramic tube is pushed out of a fuse body through the spring action to form an electric fracture, so that a circuit is broken.

However, such fuses also have some drawbacks during installation and use: the part of the fuse that takes off a mouthful comprises spring, lower contact base, insulating electricity and sealed lid, with the tight fuse of passing down contact base and insulating inside of filling up, and draw forth from the insulating outside of filling up, the kickup is fixed on the fastener of arc extinguishing pipe, nevertheless need carry out reverse anchor to the fuse when taut fuse, receive the reset action of spring potential energy, this operation difficulty is hard, the fast assembly of being not convenient for, fuse friction insulating pad edge easily makes the fuse damage in operation simultaneously, cause the fuse function to become invalid, the influence is to distribution system's protection.

Disclosure of Invention

Aiming at the defects of the existing fuse in the using process in the background technology, the invention provides the fuse for the power distribution system, which has the advantages of convenient fuse assembly and effective protection of a fuse wire from being damaged, and solves the technical problems in the background technology.

The invention provides the following technical scheme: the utility model provides a fuse for distribution system, includes the insulator, the fixing base is gone up to the top fixedly connected with of insulator, and the inside of going up the fixing base is equipped with the import line, fixing base under the below one side lateral wall fixedly connected with of insulator, and the inside of fixing base is equipped with the export line down, is located go up the inside last fixing base bottom fixedly connected with of fixing base and touch a seat, go up the bottom of touch a seat and seted up the cross slot, and go up touch a seat through cross slot and last conducting block swing joint, be located the insulator inner wall activity of going up touch a seat below cup joints the arc extinguishing pipe, the hole has been seted up on the top of arc extinguishing pipe, and the arc extinguishing pipe cup joints through last hole and last fuse tube activity, go up the bottom fixed connection of fuse pipe and last conducting block, and the bottom fixed connection of conducting block down of fuse, and the bottom of conducting block down through the fixed connection of fuse, the bottom of conducting block and the bottom of conducting block pass through the fixed connection of fixed contact block and the fixed connection of fuse, the bottom of fixed contact block and the fixed contact block of contact block and the fixed contact block, the fixed contact block and the fixed contact block is connected with the fuse pipe through the fixed contact block down, the fixed contact block, the bottom of fuse, the fixed contact block is connected with the fixed contact block, the fixed contact block is connected with the fuse.

Preferably, be located the movable hole has been seted up to the inside last fusion tube of arc extinguishing pipe and the terminal surface of lower fusion tube, the inside activity in one side of movable hole has cup jointed the movable block, and the bottom of movable block and the bottom in movable hole pass through end spring coupling, is located go up the inside movable block top fixed connection of fusion tube and go up the movable post of movable post, and the lateral wall of going up the movable post articulates there is the rotation page or leaf, is located the movable post is moved down to the inside movable block top fixed connection of fusion tube down, and the lateral wall of movable post articulates down has the rotation page or leaf, the inside activity of opposite side in movable hole cup joints the movable rod, and the outside activity of movable rod has cup jointed the side spring, the bottom of movable rod and the side contact of movable block, the lateral wall of arc extinguishing pipe is seted up porosely, and the clearing hole is cup jointed with the fixed membrane is fixed.

Preferably, the inner wall of the porcelain bushing and the inner wall of the lower contact base form a smooth vertical channel, and the size of the vertical channel is matched with the arc extinguishing tube and the lower conductive block.

Preferably, the cross-sectional shapes of the upper fusion pipe and the lower fusion pipe are both of a type.

Preferably, the fixed membrane is the insulating rubber material of one side indent, and the fixed membrane is the outside indent state when the movable rod does not contact with the fixed membrane, and the fixed membrane is the inboard indent state when the movable rod contacts with the fixed membrane.

Preferably, the section shape of the movable hole is a type, a movable block is arranged in one channel and leads to the middle of the arc extinguishing tube, a movable rod is arranged in the other channel and leads to the side wall of the arc extinguishing tube, the movable block is in a circular truncated cone shape, and the inclined plane inclination angle of the movable block is the same as the inclined plane inclination angle of the bottom end of the movable rod.

Preferably, the top end of the upper movable column is concave, the top end of the lower movable column is convex, and the sizes of the top ends of the upper movable column and the lower movable column are matched.

Preferably, four movable holes are formed in the surface of one upper fusion tube, the movable holes are uniformly arranged around the fuse wire, and the lower fusion tube is the same in structure.

The invention has the following beneficial effects:

1. the fuse tube is divided into the upper fuse tube and the lower fuse tube, the upper fuse tube and the lower fuse tube are movably sleeved with the arc extinguishing tube, one end of the upper fuse tube is fixedly connected with the upper conductive block, one end of the lower fuse tube is fixedly connected with the lower conductive block, the fuse wire penetrates through the upper conductive block, the upper fuse tube, the lower fuse tube and the lower conductive block and is fixed by the fixing ball, so that the fuse wire is simply and quickly installed in the arc extinguishing tube, time and labor are saved, the fuse wire installation process is always kept in a linear state, the fuse wire is effectively protected from being bent and rubbed, the integrity and functionality of the fuse wire are enhanced, and the fuse wire can normally work.

2. According to the invention, the upper spring is arranged between the arc-extinguishing tube and the upper conductive block, and the lower spring is arranged between the arc-extinguishing tube and the lower conductive block, when the fuse wire is fused, the compression elasticity of the upper spring and the lower spring pushes the arc-extinguishing tube, the lower fusion tube, the lower conductive block and other components to move downwards, so that the upper fusion tube and the lower fusion tube are rapidly separated, a large amount of gas generated by high temperature in the arc-extinguishing tube rushes to an arc position and compresses the arc, the purpose of rapid arc extinction is achieved, the service life of the components in the arc-extinguishing tube is effectively prolonged, the components can be recycled, and the use cost of the fuse is reduced.

3. The movable block and the components thereof are arranged between the contact surfaces of the upper fusion tube and the lower fusion tube, so that the upper movable column and the lower movable column are effectively pushed outwards by the elasticity of the bottom spring when the upper fusion tube is separated from the lower fusion tube, the airflow between the upper fusion tube and the lower fusion tube is driven to rapidly flow, the gas is further promoted to rapidly flow towards the electric arc to achieve the arc extinguishing purpose, meanwhile, the outward pushing operation of the movable block in the moving process of the upper fusion tube and the lower fusion tube promotes the movable rod to be in contact with the fixed film and extrude the fixed film, and the fixed film and the inner wall of the porcelain sleeve form an adsorption effect, so that the fixed operation of the arc extinguishing tube is realized, the arc extinguishing tube, the lower fusion tube and the lower conductive block are prevented from excessively moving downwards and extending out of the porcelain sleeve to cause corrosion and aging, the internal components of the porcelain sleeve are further protected, and the service life of the fuse is prolonged.

Drawings

FIG. 1 is a schematic view of the overall structure of the present invention in an unblown state;

FIG. 2 is an enlarged view of a portion of the structure A of FIG. 1;

FIG. 3 is an enlarged view of a portion of the structure B shown in FIG. 1;

FIG. 4 is a schematic view of the overall structure of the fuse state of the present invention;

FIG. 5 is an enlarged view of a portion of the structure of FIG. 4 at C;

figure 6 is a cross-sectional bottom view of the arc tube at the movable rod of the present invention in the state of figure 4.

In the figure: 1. a porcelain bushing; 11. an upper fixed seat; 12. a lower fixed seat; 2a, an upper contact base; 2b, a lower contact base; 3a, an upper conductive block; 3b, a lower conductive block; 4. an arc extinguishing tube; 41. fixing the film; 5a, mounting a fusion tube; 5b, a lower fusion tube; 51. a fuse; 52. fixing the ball; 6. a sealing cover; 61. an insulating pad; 7. a movable hole; 8. a movable block; 81a, an upper movable column; 81b, a lower movable column; 82. rotating the page; 9. a movable rod.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1 and 4, a fuse for a power distribution system includes a porcelain bushing 1, an upper fixing base 11 is fixedly connected to a top end of the porcelain bushing 1, an inlet line is disposed inside the upper fixing base 11, a lower fixing base 12 is fixedly connected to a side wall of a lower side of the porcelain bushing 1, an outlet line is disposed inside the lower fixing base 12, an upper contact base 2a is fixedly connected to a bottom end of the upper fixing base 11 inside the upper fixing base 11, a transverse slot is formed at a bottom end of the upper contact base 2a, the upper contact base 2a is movably connected to an upper conductive block 3a through the transverse slot, an arc extinguishing tube 4 is movably sleeved to an inner wall of the porcelain bushing 1 below the upper contact base 2a, an upper hole is formed at a top end of the arc extinguishing tube 4, the arc extinguishing tube 4 is movably sleeved to an upper melting tube 5a having a T-shaped cross-section through the upper hole, a top end of the upper melting tube 5a is fixedly connected to a bottom end of an upper conductive block 3a, and a bottom end of the upper conductive block 3a is connected to a top end of the arc extinguishing tube 4 through an upper spring, the bottom end of the arc extinguishing tube 4 is provided with a lower hole, the arc extinguishing tube 4 is fixedly connected with a lower fusion tube 5b with a T-shaped section through the lower hole, so that the upper fusion tube 5a and the lower fusion tube 5b form a tight closed environment when in contact, thereby effectively providing protection for a fuse 51, the bottom end of the lower fusion tube 5b is fixedly connected with the top end of a lower conducting block 3b, the top end of the lower conducting block 3b is connected with the bottom end of the arc extinguishing tube 4 through a lower spring, the side wall of the porcelain bushing 1 corresponding to the lower fixing seat 12 is fixedly connected with a lower contact seat 2b, the lower contact seat 2b is movably sleeved with a lower conducting block 3b, the inner wall of the porcelain bushing 1 and the inner wall of the lower contact seat 2b form a smooth vertical channel, the size of the vertical channel is adapted to the arc extinguishing tube 4 and the lower conducting block 3b, the arc extinguishing tube 4 and parts thereof can be simply taken out after the fuse 51 is fused, thereby rapidly replacing the fuse 51, labour saving and time saving, insulating pad 61 has been placed to the bottom of lower conducting block 3b, and sealed lid 6 has been placed to the bottom of insulating pad 61, and sealed lid 6 and insulator 1's bottom activity joint.

Referring to fig. 1-2 and 4, further, the centers of the upper fuse tube 5a and the lower fuse tube 5b are both provided with hollow cavities, and the hollow cavities are movably sleeved with the fuse 51, the top end of the fuse 51 penetrates through the upper conductive block 3a and is fixedly connected with the fixing ball 52 through the groove of the upper conductive block 3a, and the bottom end of the fuse 51 penetrates through the lower conductive block 3b and is fixedly connected with the fixing ball 52 through the groove of the lower conductive block 3 b.

Referring to fig. 1, 3-5, further, the end surfaces of the upper melting tube 5a and the lower melting tube 5b inside the arc extinguishing tube 4 are provided with a movable hole 7, the sectional shape of the movable hole 7 is L-shaped, a movable block 8 is arranged in one channel and leads to the middle of the arc extinguishing tube 4, a movable rod 9 is arranged in the other channel and leads to the side wall of the arc extinguishing tube 4, i.e. the movable block 8 in the shape of a circular truncated cone is movably sleeved inside one side of the movable hole 7, the bottom end of the movable block 8 is connected with the bottom end of the movable hole 7 through a bottom spring, the top end of the movable block 8 inside the upper melting tube 5a is fixedly connected with an upper movable column 81a with a concave top end, the side wall of the upper movable column 81a is hinged with a rotary leaf 82, the top end of the movable block 8 inside the lower melting tube 5b is fixedly connected with a lower movable column 81b with a convex top end, and the side wall of the lower movable column 81b is hinged with a rotary leaf 82, the sizes of the top ends of the upper movable column 81a and the lower movable column 81b are matched, the upper movable column and the lower movable column can be squeezed mutually to push the movable block 8 to move inwards when the upper molten tube 5a and the lower molten tube 5b are contacted, meanwhile, the upper molten tube 5a and the lower molten tube 5b can be combined tightly to realize stable fixing effect, the fuse protector can be prevented from moving randomly to cause the movement of internal parts, the upper molten tube 5a and the lower molten tube 5b are separated, the fuse wire 51 is pulled to be damaged, the movable rod 9 is movably sleeved in the other side of the movable hole 7, a side spring is movably sleeved on the outer side of the movable rod 9, the bottom end of the movable rod 9 is contacted with the side surface of the movable block 8, the inclined angle of the inclined surface of the movable block 8 is the same as the inclined angle of the bottom end of the movable rod 9, the movable block 8 can push the movable rod 9 to move outwards when moving outwards to realize the fixation of the arc extinguishing tube 4, the stability of the arc extinguishing tube 4 is improved, and the components such as the arc extinguishing tube 4 can be prevented from falling and being damaged due to excessive movement, the lateral wall of arc extinguishing pipe 4 is seted up porosely, and the clearing hole cup joints with fixed membrane 41 is fixed, fixed membrane 41 is the insulating rubber material of one side indent, fixed membrane 41 is the outside indent state when movable rod 9 does not contact with fixed membrane 41, fixed membrane 41 is the inboard indent state when movable rod 9 contacts with fixed membrane 41, can make and promote fixed membrane 41 and warp absorption insulator 1 inner wall when fuse 51 fusing and arc extinguishing pipe 4 glide to the certain stage at movable rod 9, make arc extinguishing pipe 4 not glide again, effectively improve the stability of 1 inner part of insulator, prevent that the part from excessively shifting out insulator 1 and corrode ageing and even drop the damage, thereby improve the life of part.

Referring to fig. 6, further, four movable holes 7 are formed in the surface of one upper fuse tube 5a, and the movable holes 7 are uniformly arranged around the fuse 51, and the lower fuse tube 5b can also extend all the rotating blades 82 when the fuse 51 is fused, so as to drive the gas in the middle of the arc extinguishing tube 4 to flow and extinguish the arc, and enhance the stability of the arc extinguishing tube 4 and prevent the arc extinguishing tube from moving excessively.

Fig. 1 is a diagram of a state that a fuse 51 is installed and not fused, at this time, the fuse 51 linearly penetrates through an upper conductive block 3a, an upper fusion tube 5a, a lower fusion tube 5b and a lower conductive block 3b, an upper contact seat 2a is clamped with the upper conductive block 3a, a lower contact seat 2b is movably sleeved with the lower conductive block 3b, the upper fusion tube 5a and the lower fusion tube 5b are attached to each other, the upper spring and the lower spring are in a compressed state, a sealing cover 6 seals the bottom end of a porcelain bushing 1, the outer side of a fixed film 41 is concave, and an upper movable column 81a, a lower movable column 81b and a movable rod 9 are all retracted into a movable hole 7, so that internal components of the fuse are stable, and a protection effect is effectively provided for a power distribution system; fig. 4 is a diagram of a fusing state of the internal fuse 51 of the fuse, at this time, the fuse 51 is broken, the upper contact seat 2a and the upper conductive block 3a are clamped, the lower contact seat 2b and the lower conductive block 3b are separated from each other, the lower conductive block 3b moves downwards, the upper fusion tube 5a and the lower fusion tube 5b are separated from each other, the upper spring and the lower spring are in a relaxed state, the sealing cover 6 is separated from the porcelain bushing 1, meanwhile, the upper movable column 81a, the lower movable column 81b and the movable rod 9 move outwards, and the movable rod 9 pushes the fixed film 41 to be in a state of inward concave and outer horizontal, so that the arc extinguishing tube 4 and the parts thereof are effectively kept stable, and the internal parts of the porcelain bushing 1 are prevented from being excessively moved downwards to cause the falling and damage of the parts.

The using method of the invention has the following working principle:

when the current exceeds the specified value to fuse the fuse 51, the compression elasticity of the upper spring pushes the arc extinguishing tube 4 to move downwards along the inner wall of the porcelain bushing 1, and the compression elasticity of the lower spring pushes the lower fusion tube 5b and parts thereof to move downwards, so that the instant thrust generated by the two springs pushes the sealing cover 6 to overcome the friction at the bottom end of the porcelain bushing 1 to push the sealing cover 6 to separate from the porcelain bushing 1, so that a technician can judge whether the fuse is fused or not according to whether the sealing cover 6 is bounced open, and the upper fusion tube 5a and the lower fusion tube 5b in the arc extinguishing tube 4 are separated from each other due to the elasticity, so that the gas generated due to high temperature in the arc extinguishing tube 4 is rapidly injected into the middle parts of the upper fusion tube 5a and the lower fusion tube 5b to achieve the purpose of effective arc extinguishing, and in addition, due to the separation of the upper fusion tube 5a and the lower fusion tube 5b, the bottom spring is not pushed to move outwards under the action of pressure any more, the upper movable column 81a and the lower movable column 81b are pushed out of the upper melting tube 5a and the lower melting tube 5b, the upper movable column 81a and the lower movable column 81b move to drive the rotating page 82 to rotate, so that airflow near the upper melting tube 5a and the lower melting tube 5b flows rapidly, the efficiency of compressing an arc at the position where the arc rushes to the arc is improved, the arc extinguishing effect is further realized, the movable block 8 moves outwards to push the movable rod 9 to move outwards, when the movable rod 9 is in contact with the fixed film 41, pressure is continuously applied to the fixed film 41, the fixed film 41 is changed from being concave being towards being concave, the adsorption effect of the fixed film 41 on the inner wall of the porcelain sleeve 1 is realized, the arc extinguishing tube 4 can realize the fixing effect after moving for a certain distance, and the damage caused by the fact that the internal parts of the porcelain sleeve 1 excessively move out of the porcelain sleeve 1 is prevented;

when a technician needs to replace the fuse 51, the lower conductive block 3b, the lower fuse tube 5b, the arc-extinguishing tube 4, the upper fuse tube 5a and the upper conductive block 3a are moved out of the porcelain bushing 1 at the moment, the fixing ball 52 is pulled to draw out the fused fuse 51, the upper fuse tube 5a and the lower fuse tube 5b are pushed to enable the two to be close to and contacted with the middle of the arc-extinguishing tube 4, the upper spring and the lower spring are in a compressed state, the new fuse 51 penetrates through the upper conductive block 3a, the upper fuse tube 5a, the lower fuse tube 5b and the lower conductive block 3b at the moment, the two ends of the fuse 51 are fixed by the fixing ball 52, then the arc-extinguishing tube 4 and parts of the arc-extinguishing tube are pushed to the inside of the porcelain bushing 1, the upper conductive block 3a is clamped with the upper contact seat 2a, the insulating pad 61 is pushed into the porcelain bushing 1, and the sealing cover 6 is clamped at the bottom end of the porcelain bushing 1, therefore, the replacement operation of the fuse 51 is achieved, the fuse is simple and convenient, friction damage to the fuse 51 is not caused, and a normal protection effect can be effectively provided for a power distribution system.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The utility model provides a fuse for distribution system, includes insulator (1), fixing base (11) are gone up to the top fixedly connected with of insulator (1), and the inside of going up fixing base (11) is equipped with the import line, fixing base (12) under the below one side lateral wall fixedly connected with of insulator (1), and the inside of fixing base (12) is equipped with outlet line, its characterized in that down: the bottom end of an upper fixed seat (11) positioned inside the upper fixed seat (11) is fixedly connected with an upper contact seat (2 a), the bottom end of the upper contact seat (2 a) is provided with a transverse groove, the upper contact seat (2 a) is movably connected with an upper conductive block (3 a) through the transverse groove, the inner wall of a porcelain sleeve (1) positioned below the upper contact seat (2 a) is movably sleeved with an arc extinguishing tube (4), the top end of the arc extinguishing tube (4) is provided with an upper hole, the arc extinguishing tube (4) is movably sleeved with the upper melting tube (5 a) through the upper hole, the top end of the upper melting tube (5 a) is fixedly connected with the bottom end of the upper conductive block (3 a), the bottom end of the upper conductive block (3 a) is connected with the top end of the arc extinguishing tube (4) through an upper spring, the bottom end of the arc extinguishing tube (4) is provided with a lower hole, the arc extinguishing tube (4) is fixedly connected with the lower melting tube (5 b) through the lower hole, the bottom end of the lower conductive block (3 b) is fixedly sleeved with the lower melting tube (5 b), the upper end of the lower conductive block (3 b) is connected with the upper conductive block (5 b), the lower movable contact seat (5 b) and the upper contact seat (5 b) is connected with the lower end of the lower melting tube (5 b), the lower contact seat (5 b) through the central spring, the central contact seat (5 b) and the central spring (5 b) is connected with the central contact seat (5 b), the top end of the fuse wire (51) penetrates through the upper conductive block (3 a) and is fixedly connected with the fixed ball (52) through the groove of the upper conductive block (3 a), the bottom end of the fuse wire (51) penetrates through the lower conductive block (3 b) and is fixedly connected with the fixed ball (52) through the groove of the lower conductive block (3 b), an insulating pad (61) is placed at the bottom end of the lower conductive block (3 b), a sealing cover (6) is placed at the bottom end of the insulating pad (61), the sealing cover (6) is movably clamped with the bottom end of the porcelain sleeve (1), a movable hole (7) is formed in the end faces of the upper melting tube (5 a) and the lower melting tube (5 b) inside the arc extinguishing tube (4), a movable block (8) is movably sleeved inside one side of the movable hole (7), the bottom end of the movable block (8) is connected with the bottom end of the movable hole (7) through a bottom spring, the movable block (8) top end inside the upper melting tube (5 a) is fixedly connected with a movable column (81 a), a side wall of the upper movable column (81 a movable column (82 a) is hinged with the movable column (81 b), and a side wall (82) is hinged with a movable column (9) inside the movable column (7) and a movable column (9) is hinged inside the movable column (81 b) and is connected with the lower movable column (7) inside the movable column (9) and a movable column (9 b) and a movable column (9) is hinged inside the movable column (7), and the outside activity of movable rod (9) has cup jointed the side spring, the bottom of movable rod (9) and the side contact of movable block (8), the lateral wall of arc-extinguishing pipe (4) is seted up porosely, and the clearing hole is fixed cup joints with fixed membrane (41), fixed membrane (41) are the insulating rubber material of one side indent, and fixed membrane (41) are the outside indent state when movable rod (9) do not contact with fixed membrane (41), and fixed membrane (41) are the inboard indent state when movable rod (9) and fixed membrane (41) contact.

2. A fuse for a power distribution system as recited in claim 1, wherein: the inner wall of the porcelain bushing (1) and the inner wall of the lower contact seat (2 b) form a smooth vertical channel, and the size of the vertical channel is matched with the arc extinguishing tube (4) and the lower conductive block (3 b).

3. A fuse for a power distribution system as recited in claim 1, wherein: the cross section shapes of the upper melting tube (5 a) and the lower melting tube (5 b) are both T-shaped.

4. A fuse for a power distribution system as recited in claim 1, wherein: the section shape of activity hole (7) is the L type, and is equipped with movable block (8) in the passageway and accesss to the middle part of arc extinguishing pipe (4), is equipped with movable rod (9) in another passageway and accesss to the lateral wall of arc extinguishing pipe (4), movable block (8) are round platform form, and the inclined plane inclination of movable block (8) is the same with the bottom inclined plane inclination of movable rod (9).

5. A fuse for a power distribution system as recited in claim 1, wherein: the top end of the upper movable column (81 a) is concave, the top end of the lower movable column (81 b) is convex, and the sizes of the top ends of the upper movable column (81 a) and the lower movable column (81 b) are matched.

6. A fuse for a power distribution system as recited in claim 1, wherein: four movable holes (7) are formed in the surface of the upper fusion tube (5 a), the movable holes (7) are uniformly arranged around the fuse wire (51), and the lower fusion tube (5 b) is arranged in the same way.