阅读说明：本技术 一种双刀直板型熔断器 (Double-blade straight plate type fuse ) 是由 庄逸尘 鄢玲 李思光 张利 唐有东 于 2020-12-24 设计创作，主要内容包括：本发明提供一种双刀直板型熔断器,包括：具有内腔的绝缘外壳；设置于内腔内的一体式铜排,铜排上设有间隔设置的两沟槽,铜排下方设有与两沟槽相对的两过弧缝隙；设置于铜排上方的开断栅片,开断栅片下部设有两开断刀片,两开断刀片分别位于两沟槽的上方；与开断栅片连接的气体发生装置；以及与气体发生装置连接的外部连接器。本发明的有益效果：通过沟槽改变铜排被切断处厚度,使铜排在沟槽位置形成薄弱狭径处,开断栅片对沟槽进行挤压切断,响应速度快；利用过弧缝隙使两沟槽处被切断后产生的电弧拉长并串联,产生高于系统电压的电弧电压,使短路电流下降直至过零,解决传统熔断器在低过载电流下的保护盲区问题。(The present invention provides a dual blade bar type fuse, comprising: an insulating housing having an interior cavity; the integrated copper bar is arranged in the inner cavity, two grooves are arranged on the copper bar at intervals, and two arc-passing gaps opposite to the two grooves are arranged below the copper bar; the breaking grid piece is arranged above the copper bar, the lower part of the breaking grid piece is provided with two breaking blades, and the two breaking blades are respectively positioned above the two grooves; the gas generating device is connected with the breaking grid piece; and an external connector connected to the gas generator. The invention has the beneficial effects that: the thickness of the cut part of the copper bar is changed through the groove, so that the copper bar forms a weak narrow diameter part at the position of the groove, the cut grid plate is cut off to extrude and cut the groove, and the response speed is high; the arc generated after the two grooves are cut off is lengthened and connected in series by utilizing the over-arc gap, the arc voltage higher than the system voltage is generated, the short-circuit current is reduced until the short-circuit current passes zero, and the problem of the protection dead zone of the traditional fuse under the low overload current is solved.)

1. A dual blade bar fuse, comprising:

an insulating housing having an interior cavity;

the integrated copper bar is arranged in the inner cavity, two grooves are arranged on the copper bar at intervals, and two arc-passing gaps opposite to the two grooves are arranged below the copper bar;

the lower part of the break grid plate is provided with two break blades which are respectively positioned above the two grooves;

the gas generating device is connected with the breaking grid piece;

and the external connector is used for triggering the gas generating device when receiving an external trigger signal, so that the gas generating device pushes the breaking grid pieces to move downwards, the two breaking blades respectively cut off the two grooves and generate electric arcs, the electric arcs entering the two arc-passing gaps are lengthened and then connected in series to increase the electric arc voltage, and the current on the copper bar is reduced to zero crossing.

2. A dual blade bar type fuse as set forth in claim 1, wherein: the arc extinguishing chamber is characterized by further comprising two arc extinguishing chambers arranged below the two arc-passing gaps, arc extinguishing materials are placed in the arc extinguishing chambers, and the two arc extinguishing chambers are relatively independent.

3. A dual blade bar type fuse as set forth in claim 2, wherein: and a separation plate is arranged between the two arc-passing gaps and separates the two arc-passing gaps and the two arc extinguishing chambers.

4. A dual blade bar type fuse as set forth in claim 1, wherein: the groove is a V-shaped groove, and the bottom of the breaking blade is a V-shaped sharp edge.

5. A dual blade bar type fuse as set forth in claim 1, wherein: the grooves are double-sided grooves.

6. A dual blade bar type fuse as set forth in claim 1, wherein: the breaking grid piece comprises a grid piece upper cover, grid piece metal pieces and a breaking cutter, the grid piece upper cover is in an inverted T shape, a fixing groove is formed in the top of the breaking cutter, two breaking blades are arranged at the bottom of the breaking cutter, the grid piece metal pieces are arranged in the fixing groove, the lower end of the grid piece upper cover abuts against the grid piece metal pieces, and the upper end of the grid piece upper cover is connected with the gas generating device.

7. A dual blade bar type fuse as set forth in claim 6, wherein: the upper part of the breaking blade is provided with an arc-shaped transition surface, and the groove is abutted against the transition surface to limit the downward movement of the breaking grid piece.

8. A dual blade bar type fuse as set forth in claim 6, wherein: an insulating tube is arranged in the inner cavity, the breaking cutter is located in the insulating tube, the upper portion of the breaking cutter is cylindrical, and the upper portion of the breaking cutter is restrained in the insulating tube.

Technical Field

The invention relates to the technical field of direct-current power system protection devices, in particular to a double-blade straight-plate fuse protector.

Background

Fuses are common short-circuit current protection devices in ac or dc circuits. The most used fuses of protection devices in existing direct current power systems, such as the fuses produced by Eaton Bussman, adopt the principle of electric heat accumulation, when the passing current generates enough heat, the metal conductor inside is fused and arcing, thereby generating arc voltage and reducing short-circuit current.

However, in the current latest low-voltage direct-current systems (such as electric vehicles, wind power, locomotives and the like), the traditional fuse has obvious problems of protection dead zone under low overload current and protection speed. For example, in order to ensure that the temperature rise during rated current flowing is not too high, a traditional fuse is designed according to about 2 times of rated current, and a margin is left. According to the action principle, the larger the rated through current is, the stronger the current-resistant capability of the device is, and the weaker the capability of breaking low-time overload current is. The minimum breaking current of a common traditional fuse is 4-5 times of rated current, and the traditional fuse cannot be protected below 4-5 times of rated current.

Meanwhile, in the requirements of some latest electric automobile manufacturers, it is mentioned that protection needs to be performed when an automobile is stationary, that is, the protection needs to be performed by receiving a command sent by an automobile sensor under the condition of no current, which cannot be realized by a traditional fuse.

The existing other novel fuses/breakers have the defects of high price, low current capacity, poor breaking performance and the like.

Disclosure of Invention

In view of this, in order to solve the problem of a dead zone of protection under low overload current of the conventional fuse, an embodiment of the present invention provides a dual-blade straight plate fuse.

An embodiment of the present invention provides a dual blade bar type fuse including:

an insulating housing having an interior cavity;

the integrated copper bar is arranged in the inner cavity, two grooves are arranged on the copper bar at intervals, and two arc-passing gaps opposite to the two grooves are arranged below the copper bar;

the lower part of the break grid plate is provided with two break blades which are respectively positioned above the two grooves;

the gas generating device is connected with the breaking grid piece;

and the external connector is used for triggering the gas generating device when receiving an external trigger signal, so that the gas generating device pushes the breaking grid pieces to move downwards, the two breaking blades respectively cut off the two grooves and generate electric arcs, the electric arcs entering the two arc-passing gaps are lengthened and then connected in series to increase the electric arc voltage, and the current on the copper bar is reduced to zero crossing.

Further, still including setting up in two cross two explosion chambers of arc slot below, place arc extinguishing material in the explosion chamber, two the explosion chamber is relatively independent.

Furthermore, a separation plate is arranged between the two arc-passing gaps, and the separation plate separates the two arc-passing gaps and the two arc extinguishing chambers.

Further, the groove is a V-shaped groove, and the bottom of the opening blade is a V-shaped sharp edge.

Further, the groove is a double-sided groove.

Furthermore, the breaking grid piece comprises a grid piece upper cover, grid piece metal pieces and a breaking cutter, the grid piece upper cover is in an inverted T shape, a fixing groove is formed in the top of the breaking cutter, two breaking blades are arranged at the bottom of the breaking cutter, the grid piece metal pieces are arranged in the fixing groove, the lower end of the grid piece upper cover abuts against the grid piece metal pieces, and the upper end of the grid piece upper cover is connected with the gas generating device.

Furthermore, an arc-shaped transition surface is arranged at the upper part of the breaking blade, and the groove is abutted against the transition surface to limit the downward movement of the breaking grid piece.

Furthermore, an insulating tube is arranged in the inner cavity, the cut-off tool is located in the insulating tube, the upper portion of the cut-off tool is cylindrical, and the upper portion of the cut-off tool is constrained in the insulating tube.

The technical scheme provided by the embodiment of the invention has the following beneficial effects: according to the double-cutter straight-plate fuse, the groove is formed in the integrated copper bar, the thickness of the cut-off part of the copper bar is changed through the groove, the copper bar forms a weak narrow-diameter part at the groove position, the cut-off grid pieces extrude and cut off the groove, and the response speed is high; the arc generated after the two grooves are cut off is lengthened and connected in series by utilizing the over-arc gap, the arc voltage higher than the system voltage is generated, the short-circuit current is reduced until the short-circuit current passes zero, the problem of a protection dead zone of the traditional fuse under low overload current is solved, the full-range breaking from zero is realized, and the low-voltage direct-current protection requirement of a new energy market is met.

Drawings

FIG. 1 is a top plan view of a dual blade bar fuse of the present invention;

fig. 2 is a schematic sectional view taken along line a-a in fig. 1.

In the figure: 1-a gland, 2-an upper outer shell, 3-a lower inner shell, 4-a lower outer shell, 5-a copper bar, 6-a breaking grid sheet, 7-a breaking blade, 8-a groove, 9-an inner cavity, 10-a breaking cutter, 11-a grid sheet metal, 12-a grid sheet upper cover, 13-an arc gap, 14-an arc extinguishing chamber, 15-an arc extinguishing material, 16-a partition plate, 17-an insulating tube, 18-a metal inner sleeve and 19-a gas generating device.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be further described with reference to the accompanying drawings.

Referring to fig. 1 and 2, an embodiment of the present invention provides a dual blade bar type fuse including:

an insulating housing having an interior chamber 9;

the integrated copper bar 5 is arranged in the inner cavity 9, two grooves 8 are arranged on the copper bar 5 at intervals, and two arc-passing gaps 13 opposite to the two grooves 8 are arranged below the copper bar;

the breaking grid piece 6 is arranged above the copper bar 5, the lower part of the breaking grid piece 6 is provided with two breaking blades 7, and the two breaking blades 7 are respectively positioned above the two grooves 8;

a gas generating device 19 connected to the breaking grid piece 6;

and the external connector is connected with the gas generating device 19 and used for triggering the gas generating device 19 when receiving an external trigger signal, so that the gas generating device 19 pushes the breaking grid pieces 6 to move downwards, the two breaking blades 7 respectively cut off the two grooves 8 and generate electric arcs, and the electric arcs entering the two arc-passing gaps 13 are lengthened and then connected in series to increase the arc voltage, so that the current on the copper bar 5 is reduced to zero crossing.

Specifically, referring to fig. 1 and 2, the casing is integrally cylindrical and includes, from top to bottom, a gland 1, an upper outer shell 2, a lower inner shell 3, and a lower outer shell 4, all of which are made of insulating materials. The upper shell 2 and the lower shell 4 are both of a cavity structure, the inner cavity 9 is arranged inside the upper shell 2, and the inner cavity 9 is a cylindrical cavity with an opening at the lower end.

Copper bar 5 set up in the upper end of lower inner shell 3, just the upper end of lower inner shell 3 with go up outer shell 2 fastening connection, go up outer shell 2 with lower inner shell 3 will copper bar 5 presss from both sides tightly fixedly, copper bar 5 with the port laminating under the inner chamber 9. Two ends of the general copper bar 5 extend out of the shell to be connected with a protected main circuit.

Copper bar 5 is integrated machine-shaping, the shape of copper bar 5 can be multiple, preferably straight board-shaped copper bar, and copper bar 5's overall resistance is less like this, and the circulation ability is strong.

The grooves 8 are formed in the upper surface of the copper bar 5 and located below the inner cavity 9, and the two grooves 8 are arranged in parallel. The groove 8 is specifically a strip-shaped groove along the width direction of the copper bar. Preferably, the groove 8 is a V-shaped groove with a V-shaped cross section, that is, the thickness of the copper bar 5 gradually decreases from the two sides of the groove 8 to the center.

Referring to fig. 2, in addition, the groove 8 may be a double-sided groove, that is, the groove 8 is also disposed on the lower surface of the copper bar 5, and the groove 8 is disposed on the back of the groove 8 on the upper surface of the copper bar 5, so that the grooves 8 are disposed at the same positions on the upper surface and the lower surface of the copper bar 5, and the copper bar 5 is located at the groove 8 to form a weak narrow diameter, which is easy to cut. A plurality of stress grooves can be simultaneously cut on the upper surface and the lower surface of the copper bar 5 by a laser cutting technology, so that two grooves 8 are simultaneously formed on the same position of the upper surface and the lower surface of the copper bar 5.

The break-off grid plate 6 is accommodated in the inner cavity 9 of the upper shell 2, and the break-off grid plate 6 is just positioned right above the two grooves 8. The breaking grid piece 6 comprises a grid piece upper cover 12, a grid piece metal piece 11 and a breaking cutter 10, wherein the grid piece upper cover 12 is in an inverted T shape, the top of the breaking cutter 10 is provided with a fixing groove, the bottom of the breaking cutter is provided with two breaking blades 7, the bottom of each breaking blade 7 is a sharp edge with a V-shaped section, and the sharp edge is positioned above the groove 8 and is opposite to the groove 8. The grid sheet metal piece 11 is arranged in the fixing groove, the lower end of the grid sheet upper cover 12 props against the grid sheet metal piece 11, and the upper end of the grid sheet upper cover is connected with the gas generating device 19.

In order to improve the insulating capability of the upper housing 2, an insulating tube 17 is arranged in the inner cavity 9, and the insulating tube 17 is arranged between the breaking tool 10 and the inner wall of the inner cavity 9 of the upper housing 2. The cutting tool 10 is located in the insulating tube 17, the upper portion of the cutting tool 10 is cylindrical, and the upper portion of the cutting tool 10 is constrained in the insulating tube 17 and can only move along the axial direction.

The gas generating device 19 is arranged at the top of the inner cavity 9 of the upper shell 2, an opening is formed in the top of the inner cavity 9 of the upper shell 2, the gas generating device 19 penetrates through the opening, the upper end of the upper shell 2 is fixedly connected with the pressing plate 1, and the pressing cover 1 presses the gas generating device 19 to fix the gas generating device. The lower part of the gas generating device 19 is connected with the upper end of the break-off grid sheet 6, the lower part of the gas generating device 19 is the output end of the gas generating device, and the triggered gas generating device 19 can push the break-off grid sheet 6 to move downwards.

A metal inner sleeve 18 is further arranged on the periphery of the joint of the gas generating device 19 and the grid upper cover 12, the gas generating device 19 is detonated to generate a large amount of gas, and the pressure in the cavity is rapidly increased in a very short time after the gas generating device 19 is detonated, so that the metal inner sleeve 18 is used for surrounding the gas generating device 19, and the structural strength of the upper shell 2 is enhanced.

The external connector is fixedly mounted on the cover 1, and the external connector is electrically connected with the gas generating device 19. The external connector may provide an interface to receive a trigger signal provided by an external system, which triggers the gas generating device 19 upon receiving the external trigger signal.

Lower shell 4 upper end with 3 lower extremes of lower inner shell fastening connection, be equipped with two explosion chambers 14 in the shell 4 down, placed arc extinguishing material 15 in the explosion chamber, each explosion chamber 14 set up in one the slot 8 below, two 14 middle parts of explosion chamber are equipped with the 16 boards of partition that upwards extend, the division board 16 with the design of 4 integral types of lower shell. The separation plate 16 separates the two arc-extinguishing chambers 14, so that the two arc-extinguishing chambers 14 are relatively independent. The two arc-passing gaps 13 are arranged on the lower inner shell 3, and each arc-passing gap 13 is arranged in the downward extending direction of one groove 8. The upper end of each over-arc slit 13 is opposite to the groove 8, and the lower end extends into one of the arc extinguishing chambers 14. Here, the lower inner shell 3 is provided with a through hole in the middle, the upper end of the partition plate 16 extends into the through hole, two arc-passing gaps 13 are formed with the two opposite side walls of the through hole, the upper end of the partition plate 16 contacts the portion of the copper bar 5 between the two grooves 8, and the two arc-passing gaps 13 are separated by the partition plate 16.

After the gas generating device 19 is triggered, the two breaking blades 7 of the breaking grid sheet 6 move downwards to respectively cut off the two grooves 8, so that the current on the main circuit is cut off, an electric arc is generated in the cut groove 8, the breaking blades 7 extrude the electric arc to enter the over-arc gap 13 to elongate the electric arc, two serial slit electric arcs are formed, and then an electric arc voltage higher than the system voltage is generated, the voltage of the electric arc can exceed the rated voltage of the main circuit, and the voltage of the electric arc can reduce the passing short-circuit current to zero crossing.

In addition, in order to limit the downward movement distance of the breaking grid piece 6, an arc-shaped transition surface is arranged at the upper part of the breaking blade 7, the breaking blade 7 moves downward and is inserted into the arc-passing gap 13, and when the transition surface reaches the upper part of the groove 8, two sides of the groove 8 abut against the transition surface to limit the continuous downward movement of the breaking grid piece 6.

Referring to fig. 2, after the two ends of the copper bar 5 of the dc fuse are connected to the main circuit of the power system, the current of the main circuit is monitored by the external system, when the current of the main circuit is short-circuited, the external system sends an external trigger signal to the gas generator 19 through the external connector, and the gas generator 19 is triggered to push the grid-breaking sheet 6 to move downward, the two blade-breaking members 7 move downward to respectively cut off the two grooves 8, arcs are generated at the cut-off positions of the two grooves 8, the arcs are equivalent to the resistors connected to the two sides of the cut-off positions of the grooves 8, the two arcs respectively enter the two arc slits 13 under the extrusion action of the blade-breaking members 7 to be elongated to form two series-connected slit arcs, the arc resistance after series connection is increased, the voltage is increased to form an overvoltage higher than the voltage of the power system, and the short-circuit current on the main circuit is forced to rapidly decrease to zero crossing, and finishing rapid breaking.

Because 5 formula structures as an organic whole of copper bar, its resistance is compared in traditional fuse, only is 1/5 ~ 1/10 of traditional fuse, compares in traditional fuse and reaches the fusing purpose through improving resistance at low current, and fuse current capacity in this application far exceeds traditional fuse, but the through-current 1500A direct current at least. In addition, because the resistance of the copper bar 5 is small, under the condition of passing the same rated current, especially under the condition of high current, the electric arc energy generated after the groove 8 is cut off is small, the breaking speed is higher, the full-range rapid breaking from 0 to higher short-circuit current can be met, the breaking capacity is higher, and the working conditions of 1.5-2 KV breaking voltage, 10KA current and 100uH inductance can be broken.

In this document, the terms front, back, upper and lower are used to define the components in the drawings and the positions of the components relative to each other, and are used for clarity and convenience of the technical solution. It is to be understood that the use of the directional terms should not be taken to limit the scope of the claims.

The features of the embodiments and embodiments described herein above may be combined with each other without conflict.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.