Molded case circuit breakers
Invention field
The present invention relates to a kind of molded case circuit breakers, relate in particular to the assembly structure of the cutout part that cross-over connection rotary moveable contact shoes is housed.
Prior art
At first, schematically show the structure of molded case circuit breakers among Fig. 7.In the figure, the main body cover of label 1 expression circuit breaker, 2 expressions disconnect and closed handle, 3 expressions, one toggle link type disconnects and close mechanism, 4 expression overcurrent tripping devices (according to bimetallic method or other similar method), and 5 expressions, one cutout part, this part comprises the arc-control device of plurality of fixed contact shoes, a movable contact and main circuit, and should the cutout part link to each other with close mechanism with disconnection.The disconnection of this circuit breaker and closed procedure are that people are known, and the on/off operation of disconnection and closed handle 2 opens or closure the movable contact shoes of cutout part 5 by disconnection and close mechanism 3.In addition, if when conduction of current is passed through main circuit, flowing through of overcurrent activates overcurrent tripping device 4, and disconnection and close mechanism 3 are carried out a cut-out and operated, and the movable contact shoes of cutout part 5 is opened, and cut off the electric current by main circuit thus.
Herein, be used to the to stop cutting-off method of part 5 comprises single disconnected method and double break method.Disclosed a kind of example of double break method in Japanese Patent Application Publication Nos.6-028964 and 6-52777, wherein the double break method has been used a kind of cutout part that a cross-over connection rotary moveable contact shoes is housed.The structure of this circuit breaker as shown in Figure 8.In this figure, the insulation crust of label 6 expression cutout parts 5,7A and 7B represent fixedly contact shoes of mains side and load side, these two kinds of contact shoes are comprised in the insulation crust 6 and mutual diagonal angle is relatively arranged, 7a represents to be arranged on each fixedly fixed contact of the point office of contact shoes, 8 expressions, one movable contact shoes, this activity contact shoes cross-over connection is the contact of contact shoes 7 fixedly, 9 expressions, one rotary drum shape contact shoes keeper, this keeper is used for maintenance activity contact shoes 8, and 10 expression arc-control devices (grid), this arc-control device is arranged on each side of movable contact shoes 8 and is comprised in the insulation shell 6.Movable contact shoes 8 applies load by a compression spring (extension spring or torsion-coil spring 11) and is held in place, and this compression spring loosely is assemblied among the through hole 9a that forms in the inner core of contact shoes keeper 9, and is assemblied in the inside of contact shoes keeper 9.The mains side fixedly end of contact shoes 7A is extracted out in insulation crust 6, to constitute a power supply side terminal part.As shown in Figure 4, in the top surface side of insulation crust 6, the load side fixedly terminal part of contact shoes 7B links to each other with the main circuit conductor of overcurrent tripping device 4.
In addition, in the structure that illustrates, each fixedly the tip portion of contact shoes 7A and 7B be bent to form a fixed contact 7a, like this when the overcurrent such as short circuit current flows through main circuit, can utilize and be applied to the fixedly tip portion of contact shoes 7A, 7B and the electromagnetic repulsion force between the movable contact shoes 8, before overcurrent tripping device 4 (referring to Fig. 7) operation, movable contact shoes 8 is opened.In addition, each fixedly the bending part of contact shoes have a yoke 12, but the magnetic field of this yoke humidification on the electric arc that produces between fixed contact in the process at failure of current and the movable contact shoes is that arc-control device 10 increases electromagnetism arc actuating forces thus.
The problem that the present invention need solve
In order to help reducing the size of molded circuit breaker, cutout part 5 will be done compactly as far as possible.
Yet in the ordinary construction of cutout shown in Figure 8 part, each mains side and the load side fixedly tip portion of contact shoes 7A and 7B are bent into U-shaped, make in the overcurrent conduction during by circuit, can produce driving and open the required electromagnetic repulsion force of movable contact shoes 8.Like this, comprise fixedly that the height H of the insulation crust 6 of contact shoes 7A and 7B must increase, the size of the part 5 that causes thus stopping increases.
In addition, as shown in Figure 9, Japanese Unexamined Patent Publication No 1-166429 has disclosed a kind of molded case circuit breakers, wherein be included in the insulation crust 6 of cutout part 5 and mutually relatively the fixedly contact shoes 7A and the 7B of oblique angle setting constitute by linear contact shoes conductor, and cross-over connection rotary moveable contact shoes 8 is being arranged between the two fixed contact 7a that fixedly tip of contact shoes 7A and 7B is located.In this assembly structure, it is linear being included in fixedly contact shoes 7A in the insulation crust 6 and the contact shoes conductor of 7B, makes the height H of cutout part 5 compare to some extent with the structure among Fig. 8 thus and reduces.On the other hand, the sense of current that flows through fixedly contact shoes 7A and 7B with flow through the identical of movable contact shoes 8, like this, fixedly can not produce between contact shoes 7A, 7B and the movable contact shoes 8 at each and to drive and to open the required bigger electromagnetic repulsion force of movable contact shoes.
Therefore, an object of the present invention is to provide a kind of molded case circuit breakers, in this circuit breaker, in order to eliminate the requirement of the height that increases the cutout part, the fixedly contact shoes of mains side and load side is made of linear fixedly contact shoes conductor, and in this circuit breaker, revised the configuration structure of fixed and movable contact shoes, thereby when overcurrent flows through circuit, can produce and drive and open the required bigger electromagnetic repulsion force of movable contact shoes.
The method of dealing with problems
In order to reach this purpose, the invention provides a kind of molded case circuit breakers that comprises the cutout part, cutout part wherein is made of the insulation crust assembly, this insulation crust assembly comprises: arc-control device, comprise in the enclosure and the fixing fixing contact shoes of contact shoes and a load side of the mains side arranged of diagonal angle mutually, at the cross-over connection activity contact shoes that fixedly extends between the contact shoes and be used for disconnecting a rotation contact shoes keeper that keeps and be connected an activity contact shoes and a compression spring with close mechanism with respect to one of circuit breaker, movable contact shoes is opened by the electromagnetic repulsion force that is produced when overcurrent flows, wherein, mains side and load side be the contact shoes conductor type substantially linearly of contact shoes fixedly, and be parallel to each other and relatively arrange by movable contact shoes, and mains side and load side fixedly contact shoes and cross-over connection are arranged on fixedly the conductor tip movable contact shoes of deciding contact partly of the contact shoes formation one Z-shaped conducting path that is assembled together.
According to this structure, fixedly contact shoes is made of linear pattern contact shoes conductor, thus with use U-shaped fixedly the ordinary construction of contact shoes compare, cutout height is partly reduced.In addition, when conduction of current is passed through circuit breaker, flow through mains side and the load side fixedly sense of current and the current opposite in direction that flows through cross-over connection activity contact shoes of contact shoes.Therefore, if there is overcurrent to flow through circuit, as the bigger electromagnetic repulsion force of couple can mains side fixedly between the tip portion of contact shoes and the movable contact shoes and load side fixedly produce between contact shoes and the movable contact shoes.This electromagnetic repulsion force can be as the driving torque that drives and open movable contact shoes.
In addition, according to the present invention,,, can carry out following specific policy based on said structure for the opening operation and the cut-out performance of further improvement activity contact shoes:
(1) one yoke is arranged on around each mains side and load side fixedly in the zone of the tip portion of contact shoes, but thus humidification on movable contact shoes magnetic field so that electromagnetic repulsion force increase.In this case, act on that the magnetic field on the electric arc that produces between the contact of fixed and movable contact shoes is increased in the failure of current process, thereby electromagnetism electric arc actuating force is increased, make electric arc guide corresponding arc-control device into thus.
(2) each mains side and load side fixedly the tip portion of contact shoes tilt to leave movable contact shoes, between tip portion and movable contact shoes, produce electromagnetic repulsion force like this and can rotate required driving torque as making movable contact shoes rotate about it the center effectively.
(3) each mains side and load side fixedly the tip portion of contact shoes be provided with narrowlyer than the conductor that wherein is positioned at after the tip portion, like this, the magnetic field that current concentration is produced in the peripheral region of tip portion with enhancing, thus the electromagnetic repulsion force that acts on the movable contact shoes increased.In this case, than the wide heat that the contact shoes conductor part absorbs and radiation produces in contact portion owing to failure of current of tip portion, the temperature of the terminal part of contact shoes rear end increases above permissible value thereby prevent to be positioned at fixedly.
(4) one magnetic shield member be arranged on each mains side and the load side zone that fixedly tip portion of contact shoes is relative in, and fixedly the tip portion of contact shoes passes through movable contact shoes fixedly contact shoes is relative with another.This structure can prevent to open the formation in the magnetic field of directive effect to hinder movable contact shoes in the rotation path of movable contact shoes.
(5) each mains side and load side fixedly the tip portion of contact shoes have along wherein longitudinally the contact shoes conductor and with another zone that fixedly tip portion of contact shoes is oppositely arranged in the slit-like space that forms, this crack is divided into two lateral parts with conducting path.Like this, can scatter in the magnetic field that produces in the neighboring area of each conductor, thereby as in (4), can suppress to open the electromagnetic repulsion force of directive effect to hinder movable contact shoes.
(6) one hot gas outlets are opened in each mains side and load side end face of the insulation crust of cutout part, thereby this outlet vertical extent is extended to the contact shoes conductor of the corresponding fixedly contact shoes of extracting out from insulation crust and from contact shoes.Thus, the hot gas that the electric arc that produces in the time of can preventing owing to big failure of current produces in the insulation crust of cutout part directly blows against each the fixedly conductor of contact shoes and periphery of conductor of extracting out from insulation crust, thereby prevents that consequent interpolar arcing phenomenon from occurring.
(7) terminal part of the fixedly contact shoes that is provided with along the bottom surface of insulation crust bends to U-shaped, and extracts out from an end of insulation crust.Like this, can prevent that the magnetic field that produces owing to flow through the electric current of contact shoes conductor from suppressing electric arc and extending in the neighboring area of terminal part, and this electric arc produces between fixed and movable contact shoes in the failure of current process, can guarantee higher cut-out performance thus.
Description of drawings
Fig. 1 is the schematic diagram that shows with example of the present invention 1 corresponding cutout part-structure; Fig. 1 (a) is for showing the end view of this cutout internal mechanism structure partly; Fig. 1 (b) is the plane graph of the fixedly contact shoes among Fig. 1 (a); And Fig. 1 (c) is the sectional view along Fig. 1 (a) center line X-X intercepting.
Fig. 2 is the schematic diagram that shows with example of the present invention 2 corresponding cutout part-structures; Fig. 2 (a) is for showing the end view of this cutout internal mechanism structure partly; Fig. 2 (b) is the plane graph of the fixedly contact shoes among Fig. 2 (a); And Fig. 2 (c) is the sectional view along Fig. 2 (a) center line X-X intercepting.
Fig. 3 is the schematic diagram that shows with example 3 corresponding structure of the present invention; Fig. 3 (a) is the fixing plane graph of contact shoes; And Fig. 3 (b) is the schematic diagram of Distribution of Magnetic Field.
Fig. 4 is the sectional view that shows with example of the present invention 4 corresponding cutout part-structures.
Fig. 5 is the sectional view that shows with example of the present invention 4 corresponding cutout part-structures, but should figure different with Fig. 4.
Fig. 6 is the sectional view that shows with example of the present invention 5 corresponding cutout part-structures.
Fig. 7 is the schematic diagram that shows the structure of a molded case circuit breakers.
Fig. 8 is the sectional view that shows the structure of the common cutout part among Fig. 7.
Fig. 9 is the sectional view that shows the structure of the another kind of common cutout part example different with Fig. 8.
Label is described
The main body cover of 1 circuit breaker
2 cutout parts
6 insulation crusts
6a hot gas outlet
The 7A mains side is contact shoes fixedly
The 7B load side is contact shoes fixedly
The 7a fixed contact
7b slit-like space
The 7c tip portion
The 7e terminal part
The U-shaped bending part of 7e-1 terminal part
8 movable contact shoes
9 contact shoes keepers
10 arc-control devices
11 compression springs
12 yokes
13 magnetic shield member
The pivot of the movable contact shoes of O
θ is the inclination angle of the tip portion of contact shoes fixedly
F opens the electromagnetic repulsion force of movable contact shoes
Embodiment
Below, to Fig. 6 embodiments of the invention are described with reference to Fig. 1.In the figure of each example, the assembly identical with Fig. 8 and Fig. 9 represented with identical label, and omitted description of them.
Example 1
Fig. 1 (a) shows and the corresponding example of claim 1 to 4 to Fig. 1 (c).In this example, mains side and load side fixedly contact shoes 7A and 7B are comprised in the insulation crust 6 of cutout part 5, and these two kinds of contact shoes 7A, 7B are made of linear substantially contact shoes conductor, and are parallel to each other and relatively are provided with through rotary moveable contact shoes 8.That is to say, the mains side contact shoes 7A that moves the bottom surface side of insulation crust 7 from the shell left side to has a tip portion 7c, and this tip portion is provided with a fixed contact 7a and surpasses the pivot O that remains on the movable contact shoes 8 in the rotary drum shape contact shoes keeper 9 and extends near the arc-control device 10 that is positioned insulation crust 6 left sides.On the other hand, the load side contact shoes 7B that moves the top surface side of insulation crust 7 from the shell right side to has a tip portion, and the pivot O that this tip portion surpasses movable contact shoes 8 extends near the arc-control device 10 that is positioned insulation crust 6 right sides.Fixedly contact shoes 7A and 7B and movable contact shoes 8 have formed a Z-shaped conducting path, and this conducting path oblique angle is provided with, thus the fixing solid contact 7a of contact shoes 7A and 7B of cross-over connection.
Here, be provided with the fixedly contact shoes 7A of fixed contact 7a and each the tip portion 7c among the 7B tilts to leave movable contact shoes 8 (inclination angle [theta]), and it is littler than the conductor width D in the fixedly contact shoes zone that is positioned at tip portion 7c rear to be arranged in the width d of conductor of tip portion 7c.In this, label 7d represents that an electric arc produces part (electric arc feeler), and it extends to corresponding arc-control device 10 from the position of fixed contact 7a.Fig. 1 (b) is the fixing plane graph of contact shoes 7A of mains side, and load side fixedly contact shoes 7B be provided with similar structures.
In addition, one U-shaped yoke 12 is assemblied on the insulation crust 6, thereby center on each fixedly rear side, right side and left side of the tip portion 7a of contact shoes 7A, 7B, in the failure of current process, increase the magnetic field act on the electric arc that produces between fixed contact and the movable contact shoes thus, make electric arc extend to the required electric arc actuating force of corresponding arc-control device 10 thereby increase.In order to reduce eddy current loss, yoke 12 is made of a stacked stalloy.
According to this structure, each that the is positioned at insulation crust 6 fixedly contact shoes conductor of contact shoes 7A, 7B is linear, make the height H of cutout part 6 compare minimizing to some extent with the ordinary construction among Fig. 8 thus, and in the ordinary construction of this Fig. 8, each fixedly the tip portion of contact shoes 7A, 7B be bent into U-shaped.In addition, the conduction by the cutout part 5 main circuit current flow through Z-shaped conducting path, and this conducting path shown in arrow i among the figure by fixedly contact shoes 7A, 7B and movable contact shoes 8 constitute.On this conducting path, the sense of current i that flows through this part each fixedly between each end of the tip portion 7c of contact shoes 7A, 7B and movable contact shoes 8 oppositely, like this based on Fig. 8 in the fixing similar principle of contact shoes of U-shaped, this electric current can fixedly produce electromagnetic repulsion force F between contact shoes 7A, 7B and the movable contact shoes 8 at each.Like this, as the structure among Fig. 8 and Fig. 9, movable contact shoes 8 applies load and closed by a compression spring that is assemblied on the contact shoes keeper 9.Therefore, along with rated current and less overcurrent can not produce bigger electromagnetic repulsion force, can prevent that thus movable contact shoes 8 from opening.On the contrary, if flow through as short circuit current (this electric current is greater than 10 to 20 times of rated current) and so on excessive electric current, electromagnetic elasticity F will overcome the elastic force of compression spring, and driving activity contact shoes 8 rotates counterclockwise so that it is opened around center of rotation O thus.In addition, owing to be increased in the magnetic field of the region generating that centers on movable contact shoes 8 by the electric current of fixed and movable contact shoes, thereby increase electromagnetism arc actuating force, the electric arc that makes the cut-out electric current that produces because movable contact shoes 8 is opened thus between fixed and movable contact shoes extends and is driven to corresponding arc-control device 10, and electric arc is extinguished at this arc-control device place.
In this case, as mentioned above, make each fixedly the tip portion 7c of contact shoes 7A, 7B tilt to leave movable contact shoes 8, can further be applied to effectively on the movable contact shoes 8 as the electromagnetic repulsion force of opening driving torque.In addition, each fixedly the conductor among the tip portion 7c of contact shoes 7A, 7B have width smaller d, and concentrate electric current to be conducted by this tip portion, strengthening, bigger electromagnetic repulsion force is acted on the movable contact shoes 8 like this around the region generating of tip portion and the magnetic field that acts on the movable contact shoes 8.
Example 2
Fig. 2 (a) shows and the corresponding example of claim 5 of the present invention to Fig. 3 (c).In this example, except that the structure shown in Fig. 1, fixedly in contact shoes 7A, the 7B magnetic shield member 13 has been installed at each mains side and load side extraly, like this, the zone between magnetic shield member 13 and movable contact shoes 8 can be by magnetic screen.Herein, be used for mains side fixedly the magnetic shield member 13 of contact shoes 7A be positioned at and the fixing zone being oppositely arranged of the tip portion 7c of contact shoes 7B of load side, and fixedly the tip portion 7c of contact shoes 7B by movable contact shoes 8 and mains side fixedly contact shoes 7A be oppositely arranged.Be used for load side fixedly the magnetic shield member 13 of contact shoes 7B be positioned at and the fixing zone being oppositely arranged of the tip portion 7c of contact shoes 7A of mains side, and mains side fixedly the tip portion 7c of contact shoes 7A and load side fixedly contact shoes 7B be oppositely arranged.Fig. 2 (b) is the fixing plane graph of contact shoes 7A of mains side, and load side fixedly contact shoes 7B structure similarly.
With aforesaid structure, shown in Fig. 2 (a), in the position that movable contact shoes 8 is opened, even when the contact portion of the movable contact shoes 8 that is positioned at each opposed end is closed into each fixedly during the mid portion of the conductor of contact shoes 7A, 7B, movable contact shoes 8 also can not be subjected to the effect of its magnetic effect of opening of overslaugh.That is to say, do not have magnetic shield member 13, conduct electricity fail to be convened for lack of a quorum the right-hand end of movable contact shoes 8 and load side fixedly between the contact shoes conductor of contact shoes 7B and the left-hand end of movable contact shoes 8 and mains side fixedly produce electromagnetic repulsion force F between the contact shoes conductor of contact shoes 7B, fixing contact shoes 7B and movable contact shoes 8 side relatively disposed thereon wherein, and fixedly contact shoes 7A and movable contact shoes 8 relatively are provided with thereunder.Like this, can open by overslaugh activity contact shoes 8.In addition, under the effect of magnetic effect, also can overslaugh drive in arc-control device 10 at electric arc movable and that fixedly produce between the contact shoes.
By the example that goes out as shown magnetic shield member 13 is set like that, magnetic screening effect can reduce the generation of the electromagnetic repulsion force f that overslaugh activity contact shoes 8 opens, and reduces the extension of the electric arc that overslaugh produces between contact shoes and the electromagnetic force of driving.This opening speed that can prevent movable contact shoes 8 in the opening operation process slows down.Like this, as shown in Figure 1, movable contact shoes 8 can be subjected to the electromagnetic repulsion force that overcurrent produces and have no to open with pausing, strengthens the cut-out performance of circuit breaker thus.
Example 3
Fig. 3 (a) shows and the corresponding application example of claim 6 of the present invention to Fig. 3 (b).In this example, fixedly contact shoes 7A and 7B have a slit-like space 7b for each, this space is along its mid portion (being the zone that magnetic shield member 13 is set in the example of Fig. 2) that vertically is formed on the contact shoes conductor, and this space is divided into two lateral parts with conducting path.Like this, shown in Fig. 3 (b), conduction current i is used to make in the magnetic field around the region generating of conductor and laterally scatters, and makes thus to stop movable contact shoes 8 to open the electromagnetic repulsion force that direction applies to reduce.This can produce the effect identical with embodiment 2, to guarantee higher cut-out performance.
Example 4
Fig. 4 and Fig. 5 show and the corresponding example of claim 7 of the present invention.In this example, have hot gas outlet 6a (can discharge in the failure of current process because electric arc and the hot gas that produces in insulation shell to the external world by this opening) in each mains side of insulation crust 6 and load side end face (right side among the figure and left side), its characteristics of these outlets are as follows:
Hot gas outlet 6a opens on the inboard of a vertical gas deflector wall 6b, and this deflector wall 6b is along the corresponding end face formation of insulation crust 6, thereby make outlet vertically extend to corresponding mains side and load side fixedly contact shoes 7A and 7B the contact shoes conductor and extend and fixedly contact shoes 7A, the 7B bottom surface that lays respectively at insulation crust 6 and end face and from here from mutually shell end face extraction.As shown in Figure 7, label 7e represents each fixedly terminal part of contact shoes 7A and 7B, and the mains side fixedly terminal part 7e of contact shoes 7A is folded into L shapedly, and is drawn to the terminal part of breaker body shell 1.On the contrary, the load side fixedly terminal part 7e straight line of contact shoes 7B is extracted out, and links to each other with overcurrent tripping device 4 among Fig. 7.
In addition, in the example of Fig. 4, hot gas outlet 6a is at the side opening of opening of movable contact shoes 8, and in the example of Fig. 5, and mains side hot gas outlet 6a is at the closed side opening of movable contact shoes 8, thereby makes it and fixedly the terminal part 7e of contact shoes 7A is spaced apart.
With this structure, (hot gas comprises the conduction composition to the hot gas that is produced in insulation crust 6 by electric arc in the failure of current process, for example because electric arc and the metallic vapour or the ion that produce from contact member) from arc-control device 10, blow out, and then the direction of hot gas is changed into plumbness shown in arrow among the figure.Like this, this gas is from fixedly contact shoes 7A and 7B discharge by exhaust outlet 6a.Can prevent that like this hot gas from directly blowing to fixedly contact shoes 7A that extracts out from insulation shell 6 and the contact shoes conductor of 7B, make terminal part 7e and their periphery height electric insulations thus, and can not be subjected to the influence of hot gas.
On the contrary, in ordinary construction, the hot gas outlet is opened simply in each end face of insulation crust, and hot gas can blow to the terminal part of fixing contact shoes and their periphery like this, thereby can cause the interpolar arcing.
Example 5
Fig. 6 shows and the corresponding example of claim 8 of the present invention.In this example, for one of fixedly contact shoes 7A, 7B in the insulation crust 6 that is included in cutout part 5, promptly, as shown in Figure 6, for the fixing contact shoes 7A of the mains side on the bottom surface side that is positioned at insulation crust 6, the contact shoes conductor of extracting out from insulation crust 6 bends to U-shaped, and to form terminal part 7e, the U-shaped bending part 7e-1 of the contact shoes conductor of vertical lifting extends to the terminal part 7e outside like this.
On the contrary, in the normal circuit breaker shown in above-mentioned Fig. 8 or the example 4, the terminal 7e of the fixedly contact shoes 7A that extracts out from each end face of insulation crust 6 is bent into L shaped, and it is extended along the shell end face.
Herein, electromagnetic force is considered to act between magnetic field and the electric arc, wherein magnetic field is to be created in the zone of the fixing contact shoes conductor of contact shoes 7A by the electric current that flows by the contact shoes conductor, and electric arc wherein produces between fixed and movable contact shoes in the failure of current process.In common structure, the electric arc that extends to arc-control device 10 is near the contact shoes conductor, and this electric arc extends along the end face of insulation crust 6, and this electric arc can be subjected to having a strong impact on of magnetic field like this.In this case, the sense of current of rising part (vertical component) that flows through the contact shoes conductor is opposite with arc current, and like this according to the Fu Laiming lefft-hand rule, magnetic field can stop electric arc to extend and push electric arc to contact.
On the contrary, curve the structure that U-shaped forms terminal part 7e at the contact shoes conductor of as shown in Figure 6 the fixedly contact shoes 7A that will extract out from insulation crust 6, electric current flows through the distance D between the vertical conductor part of U type bending part 7e-1 with the direction opposite with arc current, and the electric arc that extends between contact bigger than in the ordinary construction.Can reduce electric current owing to the contact shoes conductor that flows through U-shaped folded part 7e-1 like this centers on magnetic field that this contact shoes conductor produces electric arc is produced the influence that causes (magnetic field intensity that acts on the electric arc is inversely proportional to distance D from the contact shoes conductor).Thus, can reduce to hinder the electromagnetic force that electric arc extends, thereby guarantee preferable cut-out performance.
The structure of above-described example 1 to 5 can work separately, but by common these structures of using, can further strengthen the performance of molded case circuit breakers.Through magnetic field analysis and experiment that the inventor did, the resulting enhancing of the electromagnetic repulsion force of movable contact shoes and electric arc actuating force is fully understood and is proved.
The invention effect
As mentioned above, according to structure of the present invention, by mains side and fixedly contact shoes and a cross-over connection of load side In the cutout part of the molded case circuit breakers that the combination of rotary moveable contact shoes consists of, mains side and load side The fixing contact shoes conductor of contact shoes type substantially linearly, and be parallel to each other and be oppositely arranged by movable contact shoes, Mains side and load side fixedly contact shoes and cross-over connection are positioned at the consolidating of point office of the fixing conductor of contact shoes A cross-over connection rotary moveable contact shoes of deciding contact is configured to a kind of Z-shaped conducting path. Like this, cutout part Than using fixedly ordinary construction little of contact shoes of U-shaped.
In addition, in conducted state, flow through mains side and load side fixedly contact shoes sense of current with flow through The opposite current of cross-over connection activity contact shoes. Therefore, if there is overcurrent to flow through circuit, bigger as couple Electromagnetic repulsion force can be at mains side fixedly between the tip portion of contact shoes and the movable contact shoes and load side is fixing touches Produce between boots and the movable contact shoes. This kind electromagnetic repulsion force can be turned round as the driving that drives and open movable contact shoes Square, fixedly the ordinary construction of contact shoes is the same high with using U-shaped for its speed that can reach.
In addition, by take said structure as the basis, and use structure in the claim 2 to 8 of the present invention, Cutting off performance can be further improved.