JP2014139913A - Switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problems in which: although the use of a magnetic yoke increases electro-magnetic force acting on an arc, the increased number of components results in an increase in cost; and when a fault current of more than several kA flows, the magnetic saturation of the magnetic yoke is generated to reduce the electro-magnetic force acting on the arc, resulting in a reduction in cut-off reliability.SOLUTION: A switch includes: a first contactor 2 in which one contact point 24 of a pair of contact points which can contact and leave each other is provided, and a repulsion electric path 22 and an attraction electric path 23 are formed in an electric path reaching the one contact point; a second contactor 3 in which the other contact point of the pair of contact points is provided; and a magnetic yoke type arc horn 5 in which a magnetic yoke part 51 provided so as to face at least a part of an arc generation space formed on the one contact point and an arc horn part 52 electrically connected to the repulsion electric path are integrally formed of a magnetic body, and a cross-section reduction part 53 for increasing magnetic resistance is interposed in a magnetic path connecting between the magnetic yoke part and the arc horn part.

Description

  The present invention relates to a switch that extinguishes an arc generated between contacts that can be used for a circuit breaker for wiring, a circuit breaker, and the like to open an electric circuit.

  As a conventional switch, a U-shaped magnetic yoke made of a magnetic material and an arc horn for commutating the arc are integrally formed so that the magnetic yoke does not overlap the movable range of the movable contact. By placing the fixed contact and the movable contact in the closed state so as to cover from two directions, the electromagnetic force acting on the arc or the movable contact can be strengthened, and the arc can be quickly pulled off from the contact There is a circuit breaker designed to do this (see, for example, Patent Document 1).

JP-A-8-227648 (7th page, FIG. 1)

  In the conventional switch as described above, the magnetic flux that commutates the arc generated by the current flowing through the fixed contact to the arc horn is bypassed by the magnetic circuit formed by integrating the magnetic yoke and the arc horn. Therefore, the magnetic flux does not act on the arc, and the effect of enhancing the electromagnetic force that commutates the arc cannot be obtained sufficiently. Therefore, in an overload current region of several hundreds A or more and a short-circuit current region of several kA or more where it is difficult to remove the arc from the contact, the arc is stuck on the contact for a long time, resulting in contact deterioration. Thereby, contact resistance increases and the temperature rise between contacts may be caused. Even if the arc is commutated from the contact to the arc horn, a magnetic circuit is formed between the arc horn and the magnetic yoke, and the arc is attracted to the magnetic yoke. There is also a risk that the deterioration of the device and the shutoff reliability may be reduced. Further, in the magnetic yoke, the magnetic flux density caused by the current is increased and magnetic saturation occurs in the short-circuit current region of several kA or more, so that the effect of increasing the electromagnetic force for commutating the arc by the magnetic yoke to the arc horn is reduced and sufficient. There was a problem that the electromagnetic force could not be applied and not only the contact but also the breaking reliability was lowered.

  The present invention has been made to solve the above-described problems of the prior art, and even when the magnetic yoke and the arc horn are integrated, even when a current of several hundreds A to several kA or more flows, the movable contact or arc It is an object of the present invention to provide a switch in which sufficient electromagnetic force is applied to suppress contact deterioration and improve the reliability of interruption.

  The switch according to the present invention includes a first contactor in which one of the pair of contacts provided so as to be able to contact and separate is provided and an anti-power generation circuit and a suction circuit are formed in an electric circuit leading to the one contact. A second contact provided with the other contact of the pair of contacts, and a magnetic yoke provided so as to face at least a part of an arc generation space formed on the one contact. An arc horn portion electrically connected to the anti-power generation path is integrally formed of a magnetic material, and a cross-sectional area reduction portion is interposed in a magnetic path connecting the magnetic yoke portion and the arc horn portion so as to increase magnetic resistance. Magnetic yoke type arc horn.

  In the present invention, since the magnetic yoke type arc horn united with the magnetic yoke unit and the arc horn unit is provided with a cross-sectional area reduction unit that increases the magnetic resistance between the magnetic yoke unit and the arc horn unit. For example, in a wide current region of several hundreds A to several kA or more, the electromagnetic force that commutates the arc to the arc horn can be increased, and deterioration of the contacts can be suppressed and the interruption reliability can be improved. Further, since the number of parts does not increase, performance can be enhanced without increasing costs.

It is a side view which shows the principal part structure of the mechanism part in the opening state of the switch which concerns on Embodiment 1 of this invention, a relay part, and an arc-extinguishing chamber part. It is an assembly perspective view which shows the principal part structure of the arc-extinguishing chamber part in the open state of the switch concerning Embodiment 1 of this invention. It is explanatory drawing which shows the magnetic circuit formed with the magnetic yoke type arc horn which concerns on Embodiment 1 of this invention compared with the conventional case. It is a figure which shows the principal part structure of the magnetic yoke type arc-extinguishing board and arc protection cover vicinity in the switch concerning Embodiment 2 of this invention, (a) is side sectional drawing, (b) is FIG. 4 (a). It is sectional drawing in the IVb-IVb line | wire. It is a perspective view which shows the magnetic yoke type arc-extinguishing board shown by FIG. It is sectional drawing cut | disconnected in the center of the transversal direction of the arc-extinguishing chamber part which shows the principal part structure of the magnetic yoke type arc horn and arc protection cover vicinity in the switch concerning Embodiment 3 of this invention. It is a side view which shows the principal part structure of the magnetic yoke type arc horn and arc protection cover vicinity in the switch concerning Embodiment 4 of this invention. It is a perspective view which shows the principal part structure of the magnetic yoke type arc horn and stationary contact in the switch concerning Embodiment 5 of this invention. It is a perspective view which shows the principal part structure of the magnetic yoke type arc horn and stationary contact in the switch concerning Embodiment 6 of this invention. It is a perspective view which shows the magnetic yoke type arc-extinguishing board in the switch concerning Embodiment 7 of this invention. It is a perspective view which shows the principal part structure of the magnetic yoke type arc horn and fixed contact in the switch concerning Embodiment 7 of this invention.

Embodiment 1 FIG.
1 and 2 are a side view and an assembled perspective view, respectively, schematically showing a main part configuration of a mechanism part, a relay part, and an arc extinguishing chamber part in the opening state of the switch according to Embodiment 1 of the present invention. . Throughout the drawings, the same members or corresponding parts are denoted by the same reference numerals. In the figure, a casing 1 constituting a switch is composed of a case 11 and a cover 12 formed of an insulator, and terminal portions 21 and 31 connected to an external power circuit are provided at both ends of the casing 1. An accommodating portion 13 such as an arc extinguishing chamber A and a driving mechanism portion 7 which will be described later is provided in the central portion.

  The housing portion 13 is formed integrally with the terminal portion 21, is formed of a counter power generation path 22 and a suction power path 23, and a fixed contact in which a fixed contact (one contact) 24 is provided at a predetermined portion of the counter power generation path 22. A movable contact (second contact) that has a child (first contact) 2 and a movable contact (the other contact) 32 that contacts and separates from the fixed contact 24 and is provided to rotate around a rotation shaft 33. 3) and an arc (not shown) that is disposed above the fixed contact 2 so as to face the tip of the movable contact 3 and is generated between the fixed contact 24 and the movable contact 32 when the contact is opened. The arc extinguishing grid 4 is also provided for holding and cooling a plurality of arc extinguishing plates at a predetermined interval.

  The accommodating portion 13 further includes a pair of magnetic yoke portions 51 provided symmetrically so as to face both sides of at least a part of the arc or the fixed contact 24, and a pair of magnetic yoke portions 51. An arc horn portion 52 provided to be connected, and interposed between the magnetic yoke portion 51 and the arc horn portion 52 to constitute the connecting portion, and between the magnetic yoke portion 51 and the arc horn portion 52 A magnetic yoke type arc horn 5 integrally formed of a magnetic body having a cross-sectional area reduction portion 53 in which the cross-sectional area of the magnetic circuit formed in the above is reduced is provided. The magnetic horn type arc horn 5 has the same potential as that of the stationary contact 2, and the arc horn 52 is electrically and mechanically opposite to the stationary contact 24 in the counter power generation path 22 from the branching portion of the suction electrical path 23. Fixed.

  In the magnetic yoke portion 51, the lower end of the drawing enters the gap between the anti-power generation path 22 and the suction electric circuit 23 so that the end surface is shielded from the arc between a part of the end surface of the suction electric circuit 23 on the side of the counter-power generation path 22 and the arc generation space. The end face of the suction electric circuit 23 on the side opposite to the power generation path 22 is installed so as to shield it from the arc. As shown in FIGS. 1 and 2, a part of the suction electric path 23 facing the arc generation space formed on the fixed contact 24 is located closer to the opening direction side of the movable contact 3 than the counter power generation path 22. The anti-power generation path 22 is configured to have a step with respect to the suction electric path 23 provided symmetrically on both sides of the counter power generation path 22.

  The terminal part 31 on the movable contact 3 side is electrically connected to a relay part 6 that detects an abnormal current and outputs an opening command, and the relay part 6 and the movable contact 3 are connected to the movable contact 3. Are electrically connected on the rotating shaft 33 side. The housing 1 also houses a drive mechanism unit 7 that is a transmission destination of the opening command output from the relay unit 6, and the movable contact 3 is not illustrated with respect to the drive mechanism unit 7. The movable contact 32 is opened and closed with respect to the fixed contact 24 by being rotated around the rotation shaft 33 by the link mechanism. The open / close portion including the arc extinguishing chamber A of the housing 1 is further divided into a plurality of sections in the front-rear direction on the paper surface of FIG. An arc protective cover 8 made of an insulating material such as a polymer material is provided on the arc exposed surface of the magnetic yoke portion 51 with respect to the arc generation space.

  In addition, an exhaust port (not shown) is provided on the right side of the housing 1 in FIG. 1 in order to discharge the hot gas accompanying the arc generation to the outside of the switch. For this reason, when the internal pressure of the arc extinguishing chamber A rises when an arc is generated, a strong pressure gradient is generated between the space between the contacts 24 and 32 and the exhaust port, and the arc is pushed into the arc extinguishing grid 4. A gas flow is generated. In addition, although this Embodiment 1 demonstrates the case where the said magnetic yoke type arc horn 5 is provided with respect to the stationary contact 2, it is not limited to this. Note that the shape of the arc extinguishing plate and the arc extinguishing grid 4 and other configurations not shown are the same as those of the prior art disclosed in Patent Document 1, for example.

  Next, regarding the operation of the first embodiment configured as described above, the magnetic circuit formed by the magnetic yoke arc horn 5 and the effect of improving electromagnetic force, which are typical features of the present invention, are shown in FIG. Will be described with reference to FIG. FIG. 3 is an explanatory view showing a magnetic circuit formed of a magnetic yoke type arc horn having the cross-sectional area reduction portion 53 according to the first embodiment of the present invention, as compared with the conventional case. (B) conceptually shows the magnetic flux generated by the current flowing through the counter-power generation path 22, (a) shows a conventional magnetic yoke type arc horn without the cross-sectional area reduction portion 53, and (b) shows the first embodiment. Shows the case. (C) has shown notionally the magnetic flux by the electric current which flows through the attraction | suction electric circuit 23 of Embodiment 1. FIG. Note that the magnetic yoke arc horn 5 shown in FIG. 3A is the same as that of the first embodiment of the present invention for convenience, and only the magnetic flux indicated by the arrow B will be described below. This corresponds to the case of a yoke arc horn. Further, the suction electric circuit 23 and the like are shown flat for convenience, and therefore do not coincide with FIGS.

The conventional stationary contact is formed from one counter-power generation path and two suction electric circuits as shown in FIG. 3A, and is generated from the counter-power generation path and the suction electric circuit by a magnetic yoke arc horn without the cross-sectional area reduction portion 53. The form of magnetic flux is as follows.
First, as shown by the solid arrow B, the magnetic flux generated from the current flowing in the counter-power generation path does not pass through the arc generation space where a part of the magnetic flux is on the fixed contact by the magnetic yoke arc horn. Since it passes through the arc horn part, the electromagnetic force for driving the arc is reduced. In particular, in an overload current region of several hundreds A or more where it is difficult to extinguish the arc, there is a problem that the interruption time may be extended if the effect of improving the electromagnetic force by the magnetic yoke portion is not sufficiently utilized. In addition, the part shown with a broken line among the arrow B of Fig.3 (a) shows the lower part of the paper surface of a figure.

  On the other hand, in the switch provided with the magnetic yoke type arc horn 5 having the cross-sectional area reducing portion 53 according to the first embodiment, as shown in FIG. 3B, the magnetic yoke portion 51 and the arc horn portion 52 are provided. Is formed so that the cross section of the magnetic circuit is reduced so as to increase the magnetic resistance between them, the magnetic flux passing through the arc horn portion 52 is reduced, and the cross section of the magnetic circuit reduces the magnetic force. Saturation is likely to occur. Accordingly, it becomes difficult for the magnetic flux to pass through the arc horn portion, and as shown by the arrow C in FIG. 3B, a magnetic flux passing through the arc space above the fixed contact 24 is formed, and the effect of improving the electromagnetic force is reduced. The arc can be extinguished stably without any problems.

  In addition, since the said effect needs to flow an electric current in the counter power generation path 22, it has to provide the space | interval between the attraction | suction electric circuit 23 and the magnetic yoke type arc horn 5, and to form electrically apart. However, for example, an iron-based material having a conductivity of about 1/5 or less than a material that is a good conductor such as copper used for the anti-power generation path 22 and the suction current path 23 in the magnetic yoke arc horn 5 is used. When used, since almost no current flows through the magnetic yoke arc horn 5, the magnetic yoke arc horn 5 and the suction circuit 23 may be in contact with each other, but in this case, as shown in FIGS. The arc horn unit 21 needs to be in electrical contact with the arc driving direction side from the position where the fixed contact 24 of the anti-power generation path 22 is arranged.

  On the other hand, the magnetic flux that hinders the driving of the arc generated by the current flowing in the suction circuit 23 is represented by the magnetic shield effect by the magnetic yoke portion 51 of the magnetic yoke arc horn 5 as shown by the arrow D in FIG. It is possible to prevent the magnetic flux from reaching the arc generation space formed between the fixed contact 24 and the movable contact 32 (not shown) at the time of opening. However, this effect is obtained when the magnetic yoke portion 51 has a central surface in the thickness direction positioned closer to the suction electric circuit 23 than an intermediate position between the central positions of the counter power generation paths 22 adjacent to the central position of the suction electric circuit 23. Since the effect of the magnetic flux generated by the attraction electric path 23 is enhanced without the effect being exerted, the central surface in the thickness direction of the magnetic yoke portion 51 needs to be shifted from the intermediate position toward the counter power generation path 22 side. is there.

  When the magnetic yoke portion 51 is exposed to the arc generation space located on the fixed contact 24, the arc commutates to the magnetic yoke portion 51, and a current flows in the magnetic yoke arc horn 5, However, here, the arc-exposed surface of the magnetic yoke portion 51 is provided with an arc protective cover 8 made of an insulating material such as a polymer material. The generation space is isolated, and the surface of the magnetic yoke portion 51 is protected.

  As described above, according to the first embodiment, the magnet formed between the magnetic yoke portion 51 and the arc horn portion 52 in the magnetic yoke arc horn 5 in which the magnetic yoke portion 51 and the arc horn portion 52 are integrated. By providing the cross-sectional area reducing unit 53 that reduces the cross-sectional area of the circuit, the cross-sectional area reducing unit 53 between the magnetic yoke unit 51 and the arc horn unit 52 at the time of circuit interruption in an overload current region of several hundreds A or more, for example. As a result, a magnetic gap due to magnetic saturation is generated, and a sufficient electromagnetic force can be applied to the arc, so that contact deterioration can be suppressed and breaking reliability can be improved. Since the magnetic yoke part 51 and the arc horn part 52 are integrated via the cross-sectional area reduction part 53, the effect of improving the electromagnetic force applied to the arc can be obtained without increasing the number of parts.

  Further, in the magnetic yoke portion 51, when a short-circuit current exceeding several kA flows in the circuit, magnetic saturation occurs in almost all the portions of the magnetic yoke portion 51, but the effect of improving the electromagnetic force is reduced. According to the first embodiment, a part of the suction electric path 23 facing the arc generation space located on the fixed contact 24 is arranged on the opening direction side of the movable contact 3 with respect to the counter power generation path 22, so that the magnetic yoke Even when a large current of several kA or more at which magnetic saturation occurs in the portion 51 is interrupted, the electromagnetic force inhibiting effect based on the magnetic flux generated from the suction electric path 23 is suppressed, and the electromagnetic force that acts on the arc can be increased. This makes it possible to improve the cutoff reliability in a wide current region from the overload current region to the short-circuit current region by using the magnetic yoke portion 51 together.

  Further, in the magnetic yoke portion 51, the magnetic yoke portion 51 is disposed between a part of the end face of the suction electric path 23 on the side opposite to the power generation path 22 and the arc generation space so as to shield the end face from the arc. It is possible to further enhance the magnetic shielding effect against the magnetic flux generated from the suction electric path 23 that hinders the driving of the magnetic field, further improving the electromagnetic force acting on the arc, and suppressing the contact deterioration and improving the interruption reliability. .

  Further, an arc protection cover 8 made of an insulating material such as a polymer material is provided on the arc exposed surface of the magnetic yoke portion 51 with respect to the arc generation space so that the magnetic yoke portion 51 is isolated from the arc generation space. As a result, it becomes difficult for the arc to commutate to the magnetic yoke portion 51 and, at the same time, a slit effect (arc contraction effect) on the arc is obtained, so that the current limiting performance can be enhanced. Further, the arc can be driven from the use of a gas flow generated by the ablated gas (cooling gas) generated from the arc protection cover 8, and the arc can be easily drawn into the arc horn unit 52 or the arc extinguishing grid 4. .

Embodiment 2. FIG.
4A and 4B are diagrams showing the configuration of the main part in the vicinity of the magnetic yoke arc extinguishing plate and the arc protection cover in the switch according to Embodiment 2 of the present invention. FIG. 4A is a side sectional view, and FIG. It is sectional drawing in the IVb-IVb line | wire of (a). FIG. 5 is a perspective view showing the magnetic yoke type arc extinguishing plate shown in FIG. In the figure, a magnetic yoke type arc extinguishing plate 9 is provided so as to connect a pair of magnetic yoke portions 91 opposed to each other with an interval for increasing the electromagnetic force to the arc, and the pair of magnetic yoke portions 91. An arc-extinguishing portion 92 for extinguishing the arc, and a magnetic path interposed between the magnetic yoke portion 91 and the arc-extinguishing portion 92 and formed so as to pass through the magnetic yoke portion 91 and the arc-extinguishing portion 92 The cross-sectional area reduction part 93 which made the cross-sectional area small is provided, and it is integrally formed symmetrically.

  Further, in the magnetic yoke portion 91, the arc exposure surface of the magnetic yoke portion 91 with respect to the arc generation space on the fixed contact 24 is protected by the arc protection cover 8 </ b> A, thereby preventing arc commutation to the magnetic yoke portion 91. At the same time, the current limiting performance is enhanced by the ablation effect resulting from the melting phenomenon of the arc protective cover 8A. Further, an arc horn 25 is provided on the exhaust port side (the right side in FIG. 4) that is not illustrated with respect to the fixed contact 24 of the fixed contact 2. As shown in FIG. 4B, the counter power generation path 22 is formed so as to be located slightly closer to the movable contact than the left and right suction electric paths 23 in the figure. Other configurations are the same as those of the first embodiment.

  According to the second embodiment configured as described above, the arc can be easily driven to the arc horn 25 side and the movable contact 3 can be opened at high speed. Accordingly, when the opening of the movable contact 3 progresses, the arc is guided to the arc extinguishing portion 92 of the magnetic yoke type arc extinguishing plate 9. In this case, a magnetic force is generated between the magnetic yoke portion 91 and the arc extinguishing portion 92. The magnetic yoke portion 91 and the extinguishing member are affected by the effects of saturation and the fact that the magnet heat cannot be maintained between the arc extinguishing portion 92 or the magnetic yoke portion 91 and the arc extinguishing portion 92 by exceeding the Curie temperature. Since a magnetic gap is generated in the cross-sectional area reduction portion 93 between the arc portion 92 and the magnetic yoke portion 91 with respect to the arc, it is difficult to act on the arc, and the arc is stably stabilized until the arc is extinguished. Can be stopped.

Embodiment 3 FIG.
FIG. 6 is a cross-sectional view taken along the center of the arc extinguishing chamber portion in the short-side direction showing the configuration of the main part near the magnetic yoke arc horn and the arc protection cover in the switch according to Embodiment 3 of the present invention. In the figure, the magnetic yoke type arc horn 5 is formed in the same manner as in the first embodiment shown in FIG. The arc protective cover 8B for protecting the magnetic yoke type arc horn 5 is formed with a window hole 81 so that a part between the magnetic yoke portion 51 and the arc horn portion 52 is exposed to the arc. An arc exposure part E is provided in the vicinity from a part of the reduction part 53 to the arc horn part 52. The anti-power generation path is formed so as to be located slightly on the movable contact side with respect to the suction electric path as shown by hatching. Other configurations are the same as those of the first embodiment.

  In the third embodiment configured as described above, since the arc protective cover 8B is provided with the window hole 81, the ablated gas is easily generated from the arc protective cover 8B by the arc heat of the arc. The pressure is high near the stationary contact 24 and the pressure is low near the arc horn 52. Accordingly, a force due to a pressure gradient for inducing the arc to the arc horn unit 52 is generated, and the arc can be easily transferred to the arc horn unit 52. Furthermore, the arc exposure part E between the arc horn part 52 and the magnetic yoke part 51 is heated by the arc heat of the arc moved to the arc horn part 52, and the arc exposure part E of the magnetic yoke type arc horn 5 has a Curie temperature. Reach temperatures above.

  Therefore, according to the third embodiment, since the space between the magnetic yoke portion 51 and the arc horn portion 52 is exposed to the arc, the temperature of this portion exceeds the Curie temperature, and the magnetism of the arc exposed portion E is lost. The magnetic gap between the magnetic yoke 51 and the magnetic yoke 51 is enlarged, the action of the attractive force on the magnetic yoke 51 to the arc is reduced, and the arc can be stably retained in the arc horn 52 until the arc is extinguished. . Further, in the magnetic yoke type arc horn 5, the arc exposed portion E is melted by the arc heat, and the cross-sectional area reducing portion 53 obtained by reducing the cross section of the magnetic circuit between the magnetic yoke portion 51 and the arc horn portion 52 is cut by melting. However, as shown in FIG. 6, a part of the cross-sectional area reduction portion 53 in which the cross-section is particularly small is formed so as to be protected by the arc protection cover 8B, thereby significantly reducing the possibility of cutting. be able to.

Embodiment 4 FIG.
FIG. 7: is a side view which shows the principal part structure of the magnetic yoke type arc horn and arc protection cover vicinity in the switch concerning Embodiment 4 of this invention. In the figure, the magnetic yoke type arc horn 5A is configured so that the magnetic yoke portion 51A extends from the portion where the magnetic yoke portion 51A is opposed to the fixed contact 24 so as to substantially follow the tip end portion of the movable contact 3 and the opening track of the movable contact 32. It is formed so as to extend upward in the figure to near the opening position. The upwardly extending magnetic yoke portion 51A is covered with an arc protection cover 8C and is isolated from the arc formed when the current is interrupted. Other configurations are the same as those of the first embodiment.

  In the fourth embodiment configured as described above, by extending the magnetic yoke portion 51A to the vicinity of the opening position of the movable contact 32, an arc based on the magnetic flux generated from the counter power generation path 22 (see FIG. 2) is generated. Since the electromagnetic force for inducing the arc horn portion 52 and the arc extinguishing grid 4 or the electromagnetic force for opening the movable contact 3 can be increased to the vicinity of the opening position of the movable contact 32, The current can be quickly limited by the high-speed opening of the movable contact 3 and the electromagnetic force applied to the arc. Further, since the arc protection cover 8C is located between the contacts 24 and 32, an arc that has once moved to the back side (right side in the figure) of the arc extinguishing grid 4 due to the influence of the ablated gas generated from the arc protection cover 8C. Since it becomes difficult to return between both contacts, the arc extinguishing is stabilized and the interruption reliability is improved.

Embodiment 5 FIG.
FIG. 8 is a perspective view showing the main configuration of the magnetic yoke arc horn and the stationary contact in the switch according to Embodiment 5 of the present invention. In the fifth embodiment, the magnetic yoke arc horn in the first embodiment is further modified. In the figure, the arc horn portion 52B in the magnetic yoke arc horn 5B is bent at both ends in the direction perpendicular to the direction of the current flowing through the suction electric circuit 23 in the downward direction in FIG. And into the gap between the counter power generation path 22. And the lower end portion of the magnetic yoke portion 51B in the figure and the cross-sectional area reducing portion 53B connecting the arc horn portion 52B and the magnetic yoke portion 51B are also formed so as to enter the gap between the suction electric path 23 and the counter power generation path 22, is set up. The anti-power generation path 22 and the suction current path 23 are provided on substantially the same plane. Others are the same as in the first embodiment.

  The fifth embodiment configured as described above is configured such that the cross-sectional area reducing portion 53B and the like of the metal plates constituting the magnetic yoke arc horn 52B do not face the arc generation space. With this configuration, the risk of the magnetic yoke portion 51B dropping off due to wear of the metal plate constituting the magnetic yoke arc horn 5B due to arc heat from the arc commutated to the arc horn portion 52B is reduced. The attraction action to the magnetic yoke portion 51B can be reduced.

  Further, when the arc protection cover 8 (shown in FIG. 2) is arranged on the arc generation space side of the magnetic yoke arc horn 5B, the space for arranging the arc protection cover 8 in the vicinity of the arc horn portion 52B is expanded. Even if the arc protection cover 8 is somewhat worn out by the arc heat of the arc commutated to the arc horn portion 52B, the ablation effect by the arc protection cover 8 can be applied to the arc stably. Therefore, even when the current is interrupted many times, the arc extinguishing performance does not deteriorate, so that the reliability of interruption can be improved.

Embodiment 6 FIG.
FIG. 9 is a perspective view showing the main configuration of a magnetic yoke arc horn and a stationary contact in a switch according to Embodiment 6 of the present invention. In the sixth embodiment, the volume of the arc horn part 52C of the magnetic yoke type arc horn 5C is increased, and the cross-sectional area reduction part 53C of the magnetic circuit located between the arc horn part 52C and the magnetic yoke part 51C. The magnetic resistance is further increased, which corresponds to a modification of the fifth embodiment. In FIG. 9, the arc horn part 52 </ b> C is extended until the end part 52 </ b> C <b> 1 in a direction orthogonal to the direction of the current flowing through the suction circuit 23 reaches the upper surface part of the suction circuit 23. The cross-sectional area reducing portion 53C extends the end portion 52C1 from the magnetic yoke portion 51C side to the magnetic yoke portion 51C side by a narrow magnetic path, and further draws the suction electric path 23 and the counter electric power generation path 22 toward the counter electric power generation path 22 in the center. Is bent downward from the drawing so as to enter the gap between the suction electric path 23 and the counter power generation path 22, and is connected to the piece extended from the lower end of the figure of the magnetic yoke portion 51C. Thus, it is formed to be bent. Other configurations are the same as those of the fifth embodiment.

  In the sixth embodiment configured as described above, the volume of the arc horn portion 52C is increased as compared with the fifth embodiment, and the magnetic field of the cross-sectional area reducing portion 53C between the arc horn portion 52C and the magnetic yoke portion 51C is increased. By further increasing the resistance, the electromagnetic force for driving the arc to the arc horn part 52C side is further increased, the heat capacity of the arc horn part 52C is increased, and the wear resistance of the arc horn part is improved. Can be further increased. In the suction electric circuit shown in the figure, the cross-sectional area reducing portion 53C is arranged on the side opposite to the arc generating space of the arc horn portion, but it may be arranged on the arc generating space side as in the first embodiment. Good.

Embodiment 7 FIG.
FIG. 10 is a perspective view showing a modification of the magnetic yoke arc extinguishing plate in the switch according to Embodiment 2 of the present invention, and FIG. 11 is a deformation of the magnetic yoke arc horn in the switch according to Embodiment 6 of the present invention. It is a perspective view which shows an example. In the seventh embodiment, the magnetic yoke arc extinguishing plate formed by bending from a single plate and the arc horn portion and arc extinguishing portion of the magnetic yoke arc horn are overlapped and overlapped. ing. According to the seventh embodiment, the wear resistance of the arc extinguishing part and arc horn part corresponding to the arc commutation destination is improved, and the reliability of interruption can be further increased.
It should be noted that within the scope of the present invention, a part or all of each embodiment can be freely combined, or each embodiment can be appropriately modified or omitted.

  DESCRIPTION OF SYMBOLS 1 Housing | casing, 11 Case, 12 Cover, 13 Storage part, 2 Fixed contact (1st contact), 21 Terminal part, 22 Anti-power generation path, 23 Suction electric circuit, 24 Fixed contact (one contact), 25 Arc horn 3 movable contact (second contact), 31 terminal section, 32 movable contact (the other contact), 33 rotating shaft, 4 arc extinguishing grid, 5, 5A, 5B, 5C magnetic yoke arc horn, 51, 51A, 51B, 51C Magnetic yoke part, 52, 52B, 52C Arc horn part, 52C1 end part, 53, 53B, 53C Cross sectional area reduction part, 6 Relay part, 7 Drive mechanism part, 8, 8A, 8B, 8C Arc protection Cover, 81 window hole, 9 magnetic yoke type arc extinguishing plate, 91 magnetic yoke part, 92 arc extinguishing part, 93 cross-sectional area reduction part, A arc extinguishing chamber, E a Exposure part.

Claims (11)

Of the pair of contacts provided so as to be able to contact and separate, a first contact in which one contact is provided and an anti-power generation circuit and a suction circuit are formed in an electric circuit leading to the one contact;
A second contact provided with the other contact of the pair of contacts;
A magnetic yoke portion provided so as to face at least a part of an arc generation space formed on the one contact and an arc horn portion electrically connected to the counter-power generation path are integrally formed by a magnetic body, A magnetic yoke type arc horn having a reduced cross-sectional area interposed between the magnetic yoke portion and the arc horn portion so that the magnetic resistance is increased;
A switch characterized by comprising.   Arc protection comprising an insulator that isolates the first contactor and the magnetic yoke arc horn from an arc on at least a part of an arc exposure surface of the magnetic yoke portion facing the arc generation space on the one contact. The switch according to claim 1, further comprising a cover.   The switch according to claim 1 or 2, wherein at least a part between the magnetic yoke part and the arc horn part is exposed to an arc.   The arc horn portion is bent so that both end portions in a direction orthogonal to the direction of the current flowing through the suction electric circuit enter a gap between the suction electric circuit and the counter-power generation channel, and the cross-sectional area reduction unit is The switch according to any one of claims 1 to 3, wherein the switch is disposed in the gap.   5. The heat capacity of the arc horn portion is increased by further extending the both end portions of the arc horn portion in a direction perpendicular to the direction of the current flowing through the suction circuit. Switch.   The switch according to any one of claims 1 to 5, wherein a heat capacity of the arc horn portion is increased by forming the arc horn portion so as to overlap in two or more stages. Of the pair of contacts provided so as to be able to contact and separate, a first contact in which one contact is provided and an anti-power generation circuit and a suction circuit are formed in an electric circuit leading to the one contact;
A second contact provided with the other contact of the pair of contacts;
An arc extinguishing grid provided at a position capable of extinguishing an arc generated between the pair of contacts at the time of opening;
A magnetic yoke portion provided so as to face at least a part of an arc generation space formed on the one contact and an arc extinguishing portion for extinguishing the arc are integrally formed of a magnetic material, and the magnetic yoke A magnetic yoke type arc extinguishing plate in which a cross-sectional area reduction portion is arranged so that the magnetic resistance is increased in a magnetic path connecting a portion and the arc extinguishing portion,
An arc protective cover made of an insulator that isolates the one contact and the magnetic yoke portion from an arc on at least a part of an exposed surface of the magnetic yoke portion with respect to the arc;
A switch characterized by comprising.   The switch according to claim 7, wherein at least a part between the magnetic yoke part and the arc extinguishing part is exposed to an arc.   The switch according to claim 7 or 8, wherein a heat capacity of the arc extinguishing part is increased by forming the arc extinguishing part so as to be overlapped in two or more steps.   The at least part of the attraction electric circuit facing the arc generation space located on the one contact is disposed on the opening direction side of the second contact with respect to the counter power generation path. The switch according to any one of claims 8 to 9.   The switch according to any one of claims 1 to 8, wherein the magnetic yoke portion is installed so as to shield an end surface of the suction electric circuit on the side opposite to the power generation path from the arc. .

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