KR101678288B1 - Circuit breaker for direct-current circuit and circuit breaker device for direct-current circuit - Google Patents

Abstract

A plurality of grid plates of a circuit breaker of a DC circuit circuit breaker are provided with a U-shaped notch portion on the side of the movable contactor and side leg portions on both sides of the notch portion, and between the grid plates, Wherein a notched portion of a U-shaped shape facing the U-shaped notch portion of the grid plate is formed in the insulator, and a notched portion side surface of the grid plate at the side foot portion of the grid plate Is exposed. This makes it possible to increase the arc voltage in the small current region where the arc driving force is small without using the magnets, and to block the high-voltage direct current circuit.

Description

TECHNICAL FIELD [0001] The present invention relates to a circuit breaker for a direct current circuit and a circuit breaker for a direct current circuit,

The present invention relates to a circuit breaker for a DC circuit and a circuit breaker for a DC circuit capable of raising an arc voltage by inserting a resin between a small plate (grid plate) of the arc extinguisher.

In the case of using a circuit breaker for AC electric circuit and a DC electric circuit in a DC electric circuit, since the DC current has no current zero point, it is difficult to block a high voltage as compared with an AC electric circuit. The circuit breaker in which the energization current is in a large current region (for example, the rated current exceeds 100 A), the arc voltage is increased by the increase in the number of the soho plates and the arc voltage is increased by the self- An increase in the magnetic driving force due to the reduction in resistance and a gas driving force that drives an arc to the soho plate side by arranging an insulating member for generating a small gas around the arc and a pressure gradient of the gas, The voltage can be increased and the voltage can be increased.

However, in the case of the circuit breaker in which the energizing current is small in the current region (for example, the rated current is 100 A or less), the current is small and the gas driving force due to the magnetic driving force and the pressure gradient of the gas are small It is general to arrange the permanent magnets on both sides near the both contacts and to drive the arc at the time of interruption to the grid plate side of the SOH apparatus by the magnetic force of the permanent magnet using the Prmring's law 1). On the other hand, for the purpose of improving the current limiting performance at the time of interruption, there is known an SOHO apparatus in which the grid plate and the insulating plate are supported in a state of being separated (separated) from each other alternately (for example, , Patent Document 2).

[Patent Document 1] Japanese Utility Model Publication No. 58-188917 [Patent Document 2] JP-A-58-181235

As described above, in the conventional circuit breaker, when the voltage of the DC electric circuit is to be increased, since the current is small in the small current region, the magnetic driving force to the grid plate becomes weak, The arc driving force generated by the arc voltage increase due to the cooling gas coming from the insulating member in contact with the arc and the pressure gradient caused by the insulating member in contact with the arc can be expected, It is impossible to expect an increase in the arc voltage that occurs due to the division of the arc voltage. Therefore, it is difficult to increase the voltage in the DC electric circuit, and it has been necessary to rely on the permanent magnet.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and it is an object of the present invention to provide a circuit breaker for a direct current circuit and a circuit breaker for a direct current circuit which can block a high voltage direct current circuit without using a magnet in a small current arc .

A circuit breaker for a direct current circuit according to the present invention comprises: a base of a case; an external terminal disposed on the base at an interval; a fixed contact connected to one of the external terminals and having a fixed contact; And a plurality of grid plates provided in the vicinity of the both contact points and the stationary contactor are stacked to form an arc generated between the two contact points, Wherein the grid plate is provided with a U-shaped notch portion on the side of the movable contactor and side leg portions on both sides of the notch portion formed on the side of the movable contactor, An insulator made of resin is arranged between the grid plates of the apparatus in the stacking direction of the grid plate without a gap, and the insulator is provided with a U- And a notch side surface of the grid plate at a side foot of the grid plate is exposed.

According to the circuit breaker for a direct current circuit according to the present invention, by adding the insulator, the arc voltage in a small current region having a small arc driving force can be increased without using a magnet, and a high-voltage direct current circuit can be cut off. Other objects, features, aspects and advantages of the present invention will be further clarified from the following detailed description of the present invention with reference to the drawings.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a longitudinal sectional view showing the entire configuration of a circuit breaker for a direct current circuit according to Embodiment 1 of the present invention. FIG.
2 is an enlarged perspective view showing the SOHO apparatus of FIG.
3 is an enlarged side sectional view showing the SOHO apparatus of FIG.
Fig. 4 is an enlarged perspective view showing the SOHO device from which the movable contactor is removed from Fig. 2. Fig.
Fig. 5 is an enlarged perspective view showing the SOHO device from which the insulating member is removed from Fig. 4; Fig.
6 is an enlarged view of the grid plate in the first embodiment.
7 is an enlarged view showing the insulator in the first embodiment.
8 is a view for explaining the magnetic drive of the arc in the first embodiment.
9 is an enlarged view showing an insulator according to Embodiment 2 of the present invention.
10 is an external connection diagram of Embodiments 1 and 2. Fig.
11 is an external wiring diagram of the third embodiment.
12 is an external connection diagram of the fourth embodiment.

Embodiment 1

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a longitudinal sectional view showing the entire configuration of a circuit breaker for a direct current circuit according to Embodiment 1 of the present invention. FIG. As shown in Fig. 1, a circuit breaker 101 is constituted by using a case 10 composed of a base 11 and a cover 12 formed of an insulating material. On the base 11, circuit disconnecting units 20 as many as the number of poles (one or plural) are arranged with an interval therebetween. On the top of the circuit breaker unit 20, an opening / closing mechanism portion 30 having a known toggle link mechanism is disposed. The cover 12 covers the circuit breaker unit 20 and the opening and closing mechanism unit 30 at each pole on the base 11 so that the operation handle 31 of the opening and closing mechanism unit 30 covers the cover 12 (Window hole) 12a for the handle.

The circuit breaker units 20 of the respective poles are configured to be identical to each other and the crossbar 32 is common to the circuit breaker units 20 of the respective poles, Is arranged on the base (11) so as to be orthogonal to the unit (20). The crossbar 32 is pivoted by the opening and closing mechanism unit 30 about its axis and each of the movable contacts 23 in the circuit breaker unit 20 of each pole is mounted do. The respective movable contacts 23 of the circuit breaker units 20 of the respective poles are rotated at the same time when the cross bar 32 is rotated around the axis thereof and by the rotation of the movable contacts 23, The movable contact 22 is brought into and out of contact with the fixed contact 21. The opening and closing mechanism unit 30 is composed of a known toggle link mechanism and has a known trip bar 33 driven by a tripping device 40.

The circuit breaker unit 20 of each pole includes a power source side terminal (external terminal) 24 provided on the base 11 and a fixed contact 27 provided on the fixed contactor 27 extending from the power source side terminal 24, A movable contact 22 which is brought into contact with the fixed contact 21 and a movable contact 23 which is provided at one end of the movable contact 22 and is rotatably held by the cross bar 32, A tripping device 40 connected to the movable contactor 23 via a movable contact holder 26, a load side terminal (external terminal) 25 provided extending from the tripping device 40, And an SOH apparatus 50 which is provided in the vicinity of both contacts 21 and 22 so as to arc the arcs generated between the two contacts 21 and 22. The stationary contact 21 and the movable contact 22 constitute an open / close contact for opening and closing the electric circuit. When the movable contact 22 comes into contact with the fixed contact 21, the electric circuit between the terminals 24 and 25 is turned on and the movable contact 22 is moved from the fixed contact 21 to the open The electric circuit between the terminals 24 and 25 is turned off. At this time, the arc generated between the movable contact 22 and the stationary contact 21 is extinguished by the SOH apparatus 50.

2 is an enlarged perspective view showing the SOHO apparatus of FIG. 3 is an enlarged side sectional view showing the SOHO apparatus of FIG. Fig. 4 is an enlarged perspective view showing the SOHO device from which the movable contactor is removed from Fig. 2. Fig. Fig. 5 is an enlarged perspective view showing the SOHO device from which the insulating member is removed from Fig. 4; Fig. 6 is an enlarged view showing a grid plate, Fig. 6 (a) is a front view, and Fig. 6 (b) is a side view thereof. Fig. 7 is an enlarged view showing an insulator, Fig. 7 (a) is a front view, and Fig. 7 (b) is a side view thereof.

The plurality of grid plates 51 and the uppermost grid plate 52 made of magnetic steel plates constituting the SOHO apparatus 50 are formed in a rectangular plate shape as shown in Embodiment Mode 1 of Figures 2-7, Shaped notched portions 51a and 52a are provided on one side (movable contact side) and side feet (side feet) 51b are formed on both sides of the notched portions 51a and 52a do. By stacking the plurality of grid plates 51 and one of the uppermost grid plates 52 at predetermined intervals and holding them by the supporting plates 53a and 53b made of an insulating material, The device 50 is configured. The SOH apparatus 50 is installed such that the U-shaped notch portions 51a and 52a of the grid plate 51 and the uppermost grid plate 52 face the fixed contact 21 and the movable contact 22, And the movable contactor 23 is rotated in the space 50a defined by the U-shaped notch 51a. The uppermost grid plate 52 is provided with a bent portion 52b so that the arc can move from the movable contact 23 easily.

Around the both contact points 21 and 22 and the SOH apparatus 50 is formed an insulating layer made of a resin (for example, a polyamide resin) that covers the power source side terminal 24 and generates a low- A member 55 is provided. 3, a resin insulator 54 (for example, a polyamide resin or a polyamide resin) is interposed between the plurality of grid plates 51 and the uppermost grid plate 52 in the SOH apparatus 50, The cross section of the side plate portion 51b of the grid plate 51 on the side of the cross bar 32 in the direction of stacking of the grid plates in the entire area opposite to the grid plate, (51d) is also covered by the bent portion (54b) of the insulator (54). On the other hand, the side surface 51c of the side plate portion 51b of the grid plate 51 on the space 50a side (on the notched portion 51a side) is not covered with the insulator 54 and the side feet 51b And the side surface 51b of the side surface 51b are in contact with each other. 4 to 7, the insulator 54 is formed with a U-shaped notched portion 54a opposed to a U-shaped notched portion 51a in the grid plate 51, And is constituted by one part by a part 54c. It is not necessary to arrange the insulator 54 on the entirety between the grid plate 51 and the uppermost grid plate 52. The number of the insulators 54 may be changed according to the required arc voltage. The notch portion 54a is extended to the insulator 54 on the side opposite to the movable contact portion of the notched portion 54a (on the side opposite to the movable contactor) so that an arc is formed inside the grid plates 51 and 52 And a notch line 54d for inducing (inducing) magnetic driving is formed.

Next, the breaking operation of the circuit breaker 101 will be described. When a current equal to or greater than a predetermined value flows in the circuit breaker unit 20, the tripping device 40 rotates and pushes the trip bar 33, so that the opening / closing mechanism 30 is driven to rotate the movable contactor 23 . The movable contact 22 is opened from the fixed contact 21 by the rotation of the movable contact 23. [ When the movable contact 22 is opened, an arc due to the flowing current is to be kept at the shortest distance between the fixed contact 21 and the movable contact 22.

At this time, when the direct current of the direct current is large in the high current region (for example, the rated current exceeds 100 A), magnetism is induced in the grid plate 51 and the U- 51a of the grid plate 51 are magnetically driven in an arc (in the direction of the power source side terminal 24 in Fig. 3) in a space formed by the U-shaped notch 51a of the plurality of grid plates 51 do. Further, the arc is driven toward the SOH plate 51 by the pressure gradient in the SOH gas generated from the insulating member 55 by the arc heat. Thereafter, the arc moved toward the small platen 51 is divided into a short arc by the plurality of grid plates 51, and the arc voltage is raised by the cathode (cathode) falling voltage obtained by the division. When the arc voltage becomes higher than the power supply voltage, the arc disappears and the cutoff is completed.

On the other hand, when the direct current of the direct current is in the small current region (for example, the rated current is 100 A or less), the gas driving force due to the magnetic driving force by the arc and the pressure gradient of the soot gas becomes weak, , The arc tries to keep flowing through the space between the positive and negative contacts 21, 22. On the other hand, in Embodiment 1, in order to utilize the arc voltage rise caused by the cooling gas generated when the arc contacts the resin, a resin insulator 54 ). This shape exposes the side surface 51c of the side foot portion 51b of the grid plate 51 so as to be easily brought into contact with the arc in order to cancel the arc generated between the two contact points 21 and 22 in a rapid step. As a result, the arc voltage is increased by using the cathode drop voltage generated by the arc coming into contact with the grid plates 51 and 52.

In addition, since the insulator 54 is disposed between the grid plates 51 and 52 without gaps in the stacking direction of the grid plates, the number of the grid plates 51 and 52 can be reduced, 51 and 52 can be ensured and the arc voltage is increased. In addition, when there is a gap between the grid plates 51, 52 and the insulator 54, it is possible to avoid that the gas can not be sufficiently expected to rise because the gas slips in the direction of the power supply side terminal 24. By increasing the gas pressure and narrowing the diameter of the arc, the arc resistance is increased and the current is reduced to make it easier to block. Next, the action of the bent portion 54b of the insulator 54 will be described. Fig. 8 is a view for explaining the magnetic drive of the arc. Fig. 8 (a) shows the case where the bent portion 54b of the insulator 54 is absent, and Fig. 8b shows the case where the bent portion 54b of the insulator 54 exists. Assuming that the bent portion 54b is not in the insulator 54, the arc 56 is brought into contact with the distal end face 51d of the side foot portion 51b of the grid plate 51 There is a case to discard. If so, the magnetic flux generated around the arc 56 becomes like 56a, and becomes a magnetic flux passing through only one side foot 51b. The arc 56 can not be driven to the inner side (left side in the drawing) of the grid plate 51 and stays near the distal end face 51d of the side foot portion 51b.

On the other hand, if the front end face 51d of the side foot portion 51b is covered by the bent portion 54b, the arc is driven by the gas generated from the bent portion 54b, and the side face 51c of the side foot portion 51b, . 8 (b), the magnetic flux generated around the arc 56 is like 56b, and the arc 56 is guided by the magnetic flux passing through both side feet 51b to the grid plate (The left side in the drawing, the direction of the arrow A).

Next, the connection of the DC electric circuit 60 and the load 61 in the case of connecting the circuit breaker 102 to the DC electric circuit will be described. As shown in Fig. 10 showing the external wiring diagrams in Embodiments 1 and 2, when the circuit breaker 102 is a bipolar device, the direct current electric circuit 60 is connected to the power source side terminals 24a and 24b, (61) are connected to the load side terminals (25a, 25b) and connected in series. Although the positive side of the DC electric circuit 60 is connected to the power source side terminal 24a and the negative side of the DC electric circuit 60 is connected to the power source side terminal 24b in FIG 10, Does not matter.

According to Embodiment 1, a resin-made insulator is disposed between the grid plates of the SOHO apparatus in a stacking direction of the grid plate, and a U-shaped notch portion opposed to the U-shaped notch portion of the grid plate is formed in the insulator The arc voltage of the small current region in which the arc driving force is small can be increased without using the magnets and the high voltage DC circuit can be prevented from being generated in the high voltage direct current circuit without using the magnets because the notch side surface of the grid plate at the side foot portion of the grid plate is exposed. Can be blocked.

Since the insulator is provided with the bent portion 54b to cover the front end face of the side plate portion of the grid plate, the arc can be efficiently driven to the inside of the grid plate, and the arc voltage in the small- So that the high-voltage DC circuit can be cut off. The bent portion 54b of the insulator 54 allows the insulator 54 to be positioned when the insulator 54 is inserted between the grid plates, facilitating the assembling work.

Embodiment 2 Fig.

Fig. 9 is an enlarged view showing an insulator in the second embodiment, Fig. 9 (a) is a front view, and Fig. 9 (b) is a side view thereof. The insulator 54 is constituted by an insulator 54 excluding the joint portion 54c provided in Embodiment 1 so as to discharge the melt generated at the time of the oversize current interruption (current exceeding several kA) have. That is, the notch line 54d that extends the notched portion 54a of the insulator 54 and induces the arc reaches the half-movable contact side of the insulator 54, So as to discharge the pressure. As a result, it is possible to obtain a circuit breaker for a direct current circuit satisfying the performance of both the extra large current region, the large current region and the small current region.

Embodiment 3:

11 is an external connection diagram showing a circuit interrupter for a three pole (direct current) circuit in the third embodiment. 10 shows an example of a circuit breaker for a bipolar (pole) DC circuit. In the third embodiment, three circuit breaker units 20 similar to those of the first and second embodiments are used, And the device 103 is constituted. The circuit breaker unit 20 is the same as those of the first and second embodiments, and a description thereof will be omitted.

The positive side / negative side of the DC electric circuit 60 is connected to the power source side terminal 24a and the negative side / positive side of the DC electric circuit 60 is connected to the power source side terminal 24c, respectively, as shown in Fig. 11 And also connects the load side terminal 25a and the power source side terminal 24b. The load 61 connects the positive side / negative side to the load side terminal 25b and the negative side / positive side to the load side terminal 25c. When used in a three-wire (alternating current) AC circuit, power may be supplied to each of the power source side terminals 24a, 24b, and 24c and a load may be connected to each of the load side terminals 25a, 25b, and 25c. It can be applied to a DC electric circuit of a higher voltage by a series wiring which is separated by three points as shown in the circuit breaker 103.

Embodiment 4.

12 is an external connection diagram showing a circuit interrupter for a quadrupole (DC) circuit in the fourth embodiment. Fourth Embodiment In the fourth embodiment, the four-pole circuit breaking device 104 is constructed by using four circuit breaker units 20 identical to those of the first and second embodiments. The circuit breaker unit 20 is the same as those of the first and second embodiments, and a description thereof will be omitted.

The positive side and the negative side of the DC electric circuit 60 are connected to the power source side terminal 24a and the negative side and the positive side of the DC electric circuit 60 are connected to the power source side terminal 24d respectively, Side terminal 25a and the power-source-side terminal 24b, and connects the load-side terminal 25d and the power-source-side terminal 24c. The load 61 connects the positive side / negative side to the load side terminal 25b and the negative side / positive side to the load side terminal 25c. In addition, when used in a three-phase (four-wire) AC circuit, power is supplied to each power source side terminal 24 and load is connected to each load side terminal 25. When the circuit breaking device 104 is applied to a DC electric circuit, it can be applied to a DC electric circuit of a higher voltage by a series wiring which is four-point separated as shown in Fig.

It is also possible for the present invention to freely combine the embodiments within the scope of the invention, or to appropriately modify or omit the embodiments.

Claims (6)

And a fixed contact having a fixed contact connected to one side of the external terminal and a movable contact which is brought into contact with and separated from the fixed contact, A movable contact connected to the other of the terminals and an SOHO device provided in the vicinity of the both contacts and the stationary contactor and stacking a plurality of grid plates so as to extinguish an arc generated between the two contacts In addition,
Wherein the grid plate is provided with a U-shaped notch portion on the side of the movable contactor and side leg portions on both sides of the notch portion,
Wherein a U-shaped notch portion of the U-shaped notch portion of the grid plate opposite to the U-shaped notch portion is formed in the insulator, and the U-shaped notch portion of the grid plate is provided between the grid plates of the SOHO device, Wherein the notch side surface of the grid plate is exposed so that the insulator is disposed without any gap in the stacking direction of the grid plate in the entire area facing the grid plate. The method according to claim 1,
Wherein an insulator disposed between the grid plates of the SOHO apparatus is provided with a bent portion that covers a distal end surface of the side foot portion of the grid plate. The method according to claim 1 or 2,
The insulator disposed between the grid plates of the SOHO apparatus is provided with a notch line for extending the notch portion of the insulator to induce an arc on the side of the anti-moving contact of the notch portion of the insulator Circuit breakers for DC circuits. The method of claim 3,
Wherein the notch line extending the notch portion of the insulator to induce an arc is formed so as to discharge the melt or pressure generated when the arc current is blocked by reaching the side of the insulated movable contact. A circuit breaker for a direct current circuit, comprising three circuit breakers for a direct current circuit according to claim 1, wherein the circuit breakers for the direct current circuits are connected in series to cut off the circuit voltage. A circuit breaker for a direct current circuit, comprising four circuit breakers for a direct current circuit as claimed in claim 1, wherein the circuit breakers for the direct current circuits are connected in series to cut off the circuit voltage.

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