JP3222731B2 - Switch with arc extinguishing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switch provided with an arc extinguishing device for extinguishing an arc generated when a contact device is opened.

[0002]

2. Description of the Related Art Conventionally, in a switch such as a circuit breaker or a switch having a relatively large capacity, various types of arc extinguishing devices are used to quickly extinguish an arc generated when a contact device is opened. Are provided. As this type of arc extinguishing device, an extinguishing grid in which a plurality of magnetic plates spaced apart in the opening and closing direction of a contact device are held by an insulating frame is generally known.

[0003] This type of arc extinguishing device is arranged near the contact device, so that when the current flowing through the contact device contains a high frequency component of an audible frequency (when various devices are connected). In this case, a high-frequency component is included due to generation of a harmonic current), and the arc extinguishing device vibrates due to fluctuations in a magnetic field formed around the contact device, which may result in a growling sound.

In order to suppress such growling, it is conceivable to fix the arc extinguishing device to the body. As a configuration in which the arc extinguishing device is fixed to the body, as shown in Japanese Utility Model Laid-Open No. 2-1847, filed by the present applicant, an arc extinguishing device composed of an arc extinguishing grid is provided inside the body. A configuration for contacting the peripheral surface is conceivable. That is, in the one described in this publication,
When the body is formed by the body and the cover, and the cover is covered with the body, the support piece integrally projecting from the arc extinguishing device comes into contact with the inner peripheral surface of the cover so that the arc extinguishing device is fixed. is there.

[0005]

As described above, if the arc extinguishing device is brought into contact with the inner peripheral surface of the body and the body and the cover are connected by assembling screws or the like, the arc extinguishing device is pressed against the body. And the vibration of the arc-extinguishing device is suppressed, so that it is difficult for the growling to occur. However, in the above configuration, the arc extinguishing device is pressed against the body by the cover when the cover is covered with the body. There is a case where a gap is formed between the cover and the growl, which cannot be sufficiently suppressed, or the cover is strongly pressed against the arc-extinguishing device to cause a crack in the cover.

In order to solve this kind of problem, it is conceivable to interpose an elastic material between the arc extinguishing device and the cover. However, since an additional member is required, the assembling work becomes troublesome.
It also leads to an increase in cost. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an arc extinguishing device that suppresses humming of an arc extinguishing device without providing a separate member and that has a low possibility of damage to a body. To provide a switchgear.

[0007]

According to the first aspect of the present invention, in order to achieve the above-mentioned object, a container comprising a body having an open surface and a cover which is covered by the opening of the body is provided at a fixed position of the body. A fixed contact having a contact support piece provided with a fixed fixed contact on one surface of a cover side and having a drive coil disposed on at least one side of the fixed contact, and a movable contact having a movable contact separated from and attached to the fixed contact The drive coil includes a contact and a yoke made of a magnetic material having a pair of legs arranged on both sides of the fixed contact and having a central piece bridging one end of the cover side of both legs on the cover side. And a magnetic field in the direction connecting the two legs of the yoke is formed between the fixed contact and the movable contact, and the magnetic field in the direction connecting the two legs of the yoke is formed between the fixed contact and the movable contact. Due to the interaction of In switches having an arc extinguishing apparatus that prolong biases the arc, a pair of holding pieces for holding the yoke in contact with the outer surface of the legs piece yoke is provided on the cover.

According to a second aspect of the present invention, in the first aspect of the invention, the yoke and the cover are provided with positioning means for restricting movement of the yoke in the direction along the line of intersection between the leg piece and the center piece. According to a third aspect of the present invention, in the second aspect of the present invention, the positioning means includes a notch formed so as to straddle the center piece and the leg piece in the yoke, and a leg piece of the yoke and the center piece in the cover. Consisting of two sets of positioning projections provided on both sides of each holding piece in the direction along the intersection line, while one set of positioning projections is inserted into the notch,
The side surfaces of the other set of positioning projections abut on one surface of the yoke straddling the center piece and the leg pieces.

[0009]

According to the structure of the first aspect of the present invention, the yoke provided with the central piece bridging one end of the pair of leg pieces is provided on the cover so as to contact the outer surfaces of both leg pieces of the yoke. Since the yoke is fixed by being held by the holding piece, the direction of action of the force holding the yoke is substantially orthogonal to the direction of covering the cover on the body. No force is received from the yoke. That is, the possibility of breakage of the cover is reduced. In addition, since a separate member such as an elastic material is not required, the assembling work is easy and can be realized at low cost. Moreover, even when a current flowing through the contact device arranged near the yoke contains a harmonic component, the yoke can be held down to suppress the vibration of the yoke and prevent growling.

According to the second aspect of the present invention, the yoke moves in this direction by providing the positioning means for restricting the movement of the yoke in the direction along the intersection line between the leg piece and the center piece. In addition to the fact that the movement in the direction connecting the two leg pieces is restricted by the holding piece, the yoke can be firmly fixed. As a result, it is possible to further suppress rattling of the yoke and prevent groaning.

According to a third aspect of the present invention, there is provided the configuration of the second aspect of the present invention, wherein two sets of positioning projections are provided on the cover, and one set is inserted into a notch provided on the yoke. Since the other set is brought into contact with the end face of the yoke, it is possible to reliably restrict the movement in the direction along the line of intersection between the leg piece and the center piece. Moreover, since the two sets of positioning projections are provided on both sides of the holding piece, the yoke does not rotate around the contact portion with the holding piece as a fulcrum, and the yoke can be securely fixed with a simple configuration. .

[0012]

【Example】

(Embodiment 1) In the following embodiment, an example in which the terminal device of the present invention is used for an earth leakage breaker will be described. This terminal device can be used not only for an earth leakage circuit breaker but also for a circuit breaker for wiring, an electromagnetic contactor, and the like.

As shown in FIGS. 5 and 6, the body 10 is composed of a body 11 and a cover 12 each made of synthetic resin, and each end of the body 11 in the longitudinal direction is connected to a power source and a load, respectively. Terminal block 1 with screwed terminals
3a and 13b are formed. In this embodiment, an earth leakage breaker used for single-phase three-wire or three-phase three-wire is shown, and terminals for three poles are provided on each of the terminal blocks 13a and 13b. The terminals of each pole are insulated so as not to contact each other by partition walls 11a that partition the two side walls into three sections at both ends in the longitudinal direction of the body 11.

On the terminal block 13a, one end of a main piece 14a of the power-supply-side terminal plate 14 formed of a conductor material mainly composed of copper is exposed. Is inserted through a leg of a terminal screw 15a made of a hexagon socket bolt, and a terminal nut 15b is inserted into a leg of the terminal screw 15a.
(See FIG. 4). As shown in FIG. 7, a downwardly bent vertical piece 14b is formed at the other end of the main piece 14a of the power supply side terminal plate 14, and the widthwise central portion of the other end of the power supply side terminal plate 14 is formed. The contact support piece 14c located below the upper surface of the power supply terminal plate 14 is extended from the vertical piece 14b. Opening window 14d is formed at the other end of power supply terminal plate 14 by cutting and raising power supply terminal plate 14, and fixed contact 21 is fixed to the upper surface of contact support piece 14c exposed through opening window 14d. Is done. That is, the power supply side terminal plate functions as a fixed contact.

A yoke 16 made of a magnetic material is provided on the bottom surface of the body 11. Here, the yoke 16
Is made of a magnetic material, and the power supply side terminal plate 14 is formed of a material containing copper as a main component. Therefore, the yoke 16 has a higher resistivity than the power supply side terminal plate 14. The yoke 16 is formed such that the leg pieces 16b rise upward from both side edges of one end of the main piece 16a, and the arc running piece 16c rises upward from the other end edge of the main piece 16a. A positioning protrusion 11b (see FIG. 4) projecting from the bottom surface of the body 11 is inserted into the main piece 16a of the yoke 16.
With the yoke 16 positioned with respect to the body 11, the contact support piece 14c is mounted on the main piece 16a of the yoke 16, and the fixed contact 2 is fixed between the two leg pieces 16b of the yoke 16.
1 is located. The arc running piece 16c is a contact support piece 14c.
, And its tip protrudes above the upper surface of the contact support piece 14c. As shown in FIG. 4, the power supply side terminal plate 14 is fixed to the body 11 by screwing a fixing screw 19 inserted from the lower surface side of the body 11, and the yoke 16 has a main piece 16a. The body 11 is fixed to the body 11 so as to be sandwiched between the body 11 and the contact support piece 14c of the power supply side terminal plate 14.

On the other hand, one end of a load-side terminal plate 17 made of a conductor material mainly composed of copper is exposed on the terminal block 13b, and, like the power-supply-side terminal plate 14, the load-side terminal plate 1 is exposed.
7 is a terminal screw 15 made of a hexagon socket bolt at the one end.
a and a terminal nut 1 screwed to the leg of the terminal screw 15a
5b are provided. The load-side terminal plate 17 is connected to the body 1
1 is fixed to the body 11 by screwing a fixing screw 19 inserted from the lower surface side.

Power supply side terminal plate 14 and load side terminal plate 17
As shown in FIG. 1, holding grooves 11 d having openings on the outer surface side and the upper surface side of the body 10 are formed in the terminal blocks 13 a and 13 b on which are mounted. A connection hole 11e penetrating the bottom surface of the container 10 is formed on the bottom surface of the holding groove 11d.
The inner peripheral surface of the holding groove 11d is formed in a shape capable of preventing the rotation of the square-shaped terminal nut 15b having a reduced angle.
The inside diameter of the connection hole 11e is formed smaller than the outside diameter of the terminal nut 15b so that the terminal nut 15b does not fall out of the connection hole 11e. In the holding groove 11d, the locking groove 11 is formed on the inner peripheral surface of the opening on the outer surface side of the body 10.
f is formed, and both ends of a lid 15c formed by bending a band-shaped sheet metal are detachably attached to the locking groove 11f. The lid 15c has a vertical width approximately equal to the depth of the holding groove 11d, and both ends are bent in a substantially V-shape. The lid 15c is fixed to the holding groove 11d by utilizing the elasticity of the V-shaped portion.

When an external conductor (for example, an electric wire having a terminal having a round connection portion) is connected to the power supply terminal plate 14 or the load terminal plate 17 from the side of the body 10, the terminal Attach the nut 15b to the holding groove 11d,
The lid 15c is attached to the holding groove 11d. In this state, when the terminal screw 15a is tightened,
a is screwed into a terminal nut 15b to form a terminal screw 15a.
a and the terminal nut 15b.

The other end of the load-side terminal plate 17 is connected to one end of a heater plate 22 forming a substantially U-shaped electric path in one plane. The load-side terminal plate 17 and the heater plate 22 are arranged so as to be substantially orthogonal. One end of an indirectly heated bimetal plate 41 is fixed to the other end of the heater plate 22, and the other ends of the three-pole heater plates 22 are connected to the circuit conductors 23 a, 23 b, 2.
One end of 3c (see FIG. 8) is connected. Circuit conductor 23
The intermediate portions of a, 23b, and 23c are inserted into the leakage current detection device 30 and the other end is connected to one end of the movable contact 25 through the braided wire 24. The other end of the movable contact 25 is provided with a movable contact 26 constituting a contact device together with the fixed contact 21 described above. That is, a contact device including a fixed contact 21 and a movable contact 26, a movable contact 25, a braided wire 24, circuit conductors 23a, 23b, 23c, and a heater plate are provided between the power supply side terminal plate 14 and the load side terminal plate 17. 22 is formed.

Incidentally, the heater plate 22 and the load-side terminal plate 1
7, a terminal separating plate 18 made of a magnetic material and having an exhaust hole formed therein is opposed to the heater plate 22 so as to be opposed to the side wall of the body 11 and the partition 11a and between the terminal screw 15a and the partition 11a. Held between each other. Immediately below the terminal separation plate 18 with the load-side terminal plate 17 interposed therebetween, a suction plate 42 formed of a magnetic material in a substantially U-shape that is open upward is disposed. A plunger 43 extending upward is fixed to the suction plate 42, and the suction plate 42 is a return spring 4 composed of a coil spring sandwiched between the suction plate 42 and the load-side terminal plate 17.
4 is urged downward by the spring force. A cutout is formed at the side of the load-side terminal plate 17 at a position where the end surfaces of both leg pieces of the suction plate 42 and the lower end surface of the terminal separation plate 18 face each other. That is, the front end surfaces of both leg pieces of the suction plate 42 and the lower end surface of the terminal separation plate 18 directly face each other.

Therefore, when a current of several tens times or more of the rated current flows through the main circuit, such as a short-circuit current, the magnetic field formed around the heater plate 22 magnetizes the terminal separation plate 18 and causes the suction plate to be magnetized. Reference numeral 42 is attracted to the terminal separation plate 18 against the spring force of the return spring 44. That is, when the short-circuit current flows in the main electric circuit, the suction plate 42 and the plunger 43 move upward. Further, when an overcurrent of several times the rated current flows through the main circuit, the bimetal plate 41 is heated by the heat generated by the heater plate 22, and the bimetal plate 41 is heated.
Is curved in a direction away from the heater plate 22. Here, a push screw 45 is screwed onto the upper end of the bimetal plate 41 so that the amount of screw of the push screw 45 can be adjusted.

A trip device 50 is provided at the center of the body 11.
Is stored. Although a general trip device 50 is used, a brief description will be given. In the trip device 50, as shown in FIG. 9, a latch link 52, a latch plate 53, a cradle 54, and a handle 55 are connected to shafts 52a and 53, respectively.
a, 54a and 55a, which are pivotally attached to the metal frame 51. In addition, the central one-pole movable contact 25 of the three poles
And cradle 54, one ends of links 56a, 56b are pivotally connected, and the other ends of both links 56a, 56b are pivotally connected. That is, the cradle 54 and the movable contact 25 are connected via the two links 56a and 56b. A latch return spring 57 composed of a torsion coil spring is mounted on a shaft 51a fixed to the frame 51, and one end of the latch return spring 57 is connected to a latch link 52, respectively.
And the latch plate 53. Here, the latch return spring 57 urges the latch plate 53 clockwise around the shaft 53a in FIG. A handle return spring 58, which is a tension spring, is mounted between the handle 55 and the shaft pin 56 on which the links 56a and 56b are mounted.

The movable contact 25 is held swingably in the plane of FIG. 9 with respect to the interlocking body 59 made of synthetic resin, and a contact pressure formed by a coil spring is provided between the movable contact 25 and the interlocking body 59. The spring 46 is held. The contact pressure spring 46 is connected to the movable contact 2.
When the contact 6 is closed with respect to the fixed contact 21, the movable contact 25 is urged in a direction to apply the contact pressure, and when the movable contact 26 is opened with respect to the fixed contact 21, the movable contact 26 is separated from the fixed contact 21. The movable contact 25 is biased in the direction. The interlocking body 59 has a shaft portion 59a rotatably supported by the body 11, and holds all three-pole movable contacts 25. Accordingly, the other two-pole movable contacts 25 also open and close in conjunction with the opening and closing operations of the one-pole movable contact 25.

On the other hand, an interlocking bar 47 is supported on the body 11 so as to straddle the three poles. As shown in FIG. 7, the interlocking bar 47 is moved upward by the plungers 43 described above. When pushed by the plunger 43, the interlocking bar 47
Is rotated counterclockwise in FIG. 9 around the bearing part 3
The kick pieces 47a are provided. Also, the bimetal plate 41
There are provided three pressing pieces 47b, which are pushed by the push screws 45 screwed to the bimetal plate 41 when the is bent to rotate the interlocking bar 47 counterclockwise around the supporting part in FIG. Further, the interlocking bar 47 is provided with a set cylinder portion 47c into which a set piece 52b protruding from the latch link 52 is inserted.

The above-mentioned handle 55 protrudes from the upper surface of the body 10 so as to be capable of being turned upside down. When the handle 55 is tilted to the left end side as shown in FIG. In this state, the set piece 52b of the latch link 52 is inserted into the set cylinder portion 47c of the interlocking bar 47. At this time, since the latch plate 53 is locked by the cradle 54, the force for rotating the latch plate 53 clockwise around the shaft 53a by the spring force of the latch return spring 57 is reduced. The latch link 52 is provided with a latch return spring 57.
9 rotates counterclockwise around the shaft 52a, but stops at the position shown in FIG. That is, in the state of FIG. 9, the latch plate 53 is kept in contact with the latch link 52.
The cradle 54 is also locked to the latch plate 53 to prevent rotation about the shaft 54a. At this time, the spring force of the handle return spring 58 is applied to the link 56a,
56b acts in a direction to develop in a straight line, and the movable contact 25 is pushed downward. That is, the movable contact 26 is kept at a position where it contacts the fixed contact 21.

On the other hand, when the handle 55 is tilted to the right end as shown in FIG. 10 in a state where the cradle 54 is engaged with the latch plate 53, the upper end of the handle return spring 58 is pivotally connected to the link 56b relative to the cradle 54. Therefore, the links 56a and 56b are bent in a rectangular shape, and the movable contact 25 is pulled upward. That is,
The movable contact 26 opens away from the fixed contact 21.

The cradle 54 is attached to the latch plate 53.
Is engaged, the interlocking bar 47 is
11, the set piece 52 b of the latch link 52 is pressed by the inner surface of the set tube portion 47 c of the interlocking bar 47 and moves downward as shown in FIG. 11. That is, the latch plate 53 is connected to the latch link 5.
As a result, the force for rotating the latch plate 53 clockwise around the shaft 53a is released, and the latch plate 53 rotates clockwise. At this time, Cradle 5
4 is also disengaged from the latch plate 53 and the cradle 54 is released.
Can rotate freely, and the links 56a and 56b are bent by the spring force of the handle return spring 58,
The movable contact 25 is pulled up. That is, the movable contact 26 separates from the fixed contact 21 and opens. Such an operation is generally called a trip operation.

In order to return the latch plate 53 and the cradle 54 from the disengaged state to the engaged state as shown in FIG. 11, the handle 55 may be tilted to the right end. At this time, the cradle 54 is
5b, the latch link 52 rotates clockwise about the shaft 54a, and the latch link 52 is pressed by the handle 55 to rotate counterclockwise about the shaft 52a. That is, if the handle 55 is sufficiently tilted to the right end side, as shown in FIG.
The cradle 54 is engaged with the latch plate 53, and the movable contact 26 returns to the state where the fixed contact 21 is opened.
To close the movable contact 26 with respect to the fixed contact 21,
Thereafter, the handle 55 may be tilted to the left end.

In the above-described trip operation, the plunger 43 is moved upward by the short-circuit current, and the interlocking bar 47 is moved.
The kick piece 47a is pushed upward, or the bimetal plate 41 is bent by an overcurrent, and the push screw 45
This operation is performed when the user presses “b”, activates the leakage current detection device 30 as described later, or presses the trip operation confirmation button 48 provided on the cover 12. The trip operation confirmation button 48 is held by the cover 12, and the trip operation confirmation button 4 is provided by an inclined surface 48a formed at the lower end.
When 8 moves downward, the interlocking bar 47 is rotated counterclockwise around the pivot position. The trip operation confirmation button 48 is urged upward by a button return spring 49 made of a coil spring, and the upper surface of the trip operation confirmation button 48 stops at a position slightly lower than the upper surface of the cover 12.

By the way, on the power supply side terminal plate 14, a member constituting the arc extinguishing device 60 together with the power supply side terminal plate 14 and the yoke 16 is arranged. That is, the arc extinguishing device 60 includes the power supply side terminal plate 14 and the yoke 16, the insulating frame 61 made of synthetic resin, and the magnetic yoke 62 mounted on the insulating frame 61. The yoke 62 is formed in a substantially U-shape opened downward by bridging the upper ends of a pair of leg pieces 62b with a central piece 62c.
A part of the lower end of 2b is located below the main piece 14a of the power supply terminal plate 14. Also, both leg pieces 62b of the yoke 62
In order to form a gap on the side edge near the terminal screw 15a so as to allow arc gas to pass while shielding the arc, a plurality of grid pieces 62
7 is extended, and the opening on the left front side of the yoke 62 in FIG. 7 is covered by the grid piece 62a of both leg pieces 62b.
That is, in the vertical direction, the grid pieces 62a are alternately provided in a staggered manner from the leg pieces 62b, and the grid pieces 62a
Are separated from each other in the thickness direction of the grid piece 62a.
A gap is formed between them.

As described above, the contact support piece 14c provided with the fixed contact 21 in the power supply terminal plate 14 extends from the vertical piece 14b provided at the right end of the power supply terminal plate 14, and When the fixed contact 21 and the movable contact 26 are opened and an arc is generated, the power supply side terminal plate is passed through the contact support piece 14c, the vertical piece 14b, and the mounting portion of the terminal screw 15a. An electromagnetic force acts between the magnetic field generated by the current flowing through 14 and the arc,
The arc will be elongated in the direction of the terminal screw 15a. That is, the main piece 14a of the power supply side terminal plate 14 and the vertical piece 1
A substantially U-shaped portion formed by the contact window 4b and the contact support piece 14c functions as a drive coil.
By forming 4d, drive coils are formed on both sides of the fixed contact 21.

Since the two yokes 16, 62 are arranged vertically as shown in FIG. 4, the magnetic flux generated by the drive coils forms a magnetic field near the fixed contact 21 only between the two drive coils. Except during the interval, the light passes through the yokes 16 and 62. That is, if the magnetic flux formed by the drive coils forms a magnetic field other than between the two drive coils, an electromagnetic force that causes the arc to travel in a direction opposite to that between the drive coils acts on the arc. Is provided, the arc can travel in one direction without applying such an electromagnetic force and can be efficiently extended. Further, when the arc travels, the arc shifts to the arc traveling piece 16c. Since the arc traveling piece 16c has a higher resistivity than the contact support piece 14c, the arc current is reduced and the arc is quickly extinguished. Is done.

The insulating frame 61 has a function of positioning the yoke 62 and a function of efficiently extinguishing the arc without releasing the pressure exerted by the arc gas. Further, the insulating frame 61 is formed of a material that releases an arc-extinguishing gas when decomposed by the heat generated by the arc (this type of material is known), thereby further enhancing the arc-extinguishing performance. The insulating frame 61 is interposed between the two leg pieces 16b of the yoke 16 and the contact support pieces 14c, prevents a part of the arc from flying to the two leg pieces 16b of the yoke 16, and allows most of the arc to travel through the arc running piece. 14c. In addition, the contact support piece 14c is located below the main piece 14a, and the tip of the arc traveling piece 16c is projected upward from the contact support piece 14c provided with the fixed contact 21.
It becomes easy to transfer the arc to the arc traveling piece 16c. An exhaust plate 63 for discharging arc gas to the outside of the housing 10 is provided at a portion corresponding to between the arc extinguishing device 60 and the terminal screw 15a.

By the way, the cover 12 is shown in FIGS.
As shown in FIG. 5, the yoke 62 is fixed to suppress the vibration of the yoke 62. That is, the cover 1
In the part where the upper end of the yoke 62 is inserted in 2,
A pair of holding pieces 12a are provided to abut on the outer surfaces of the leg pieces 62b of the yoke 62, respectively. The holding piece 12a has an inclined surface that is inclined so that the distance between the holding piece 12a and the body 11 increases, and when the body 12 is covered with the cover 12, the yoke 62 moves along the inclined surface between the two holding pieces 12a. It is led to. Also, on both sides in the thickness direction of each holding piece 12a,
The positioning protrusions 12b and 12c are formed. The positioning protruding pieces 12b and 12c facing each other are inclined so that the distance between them increases as the body approaches the body 11. on the other hand,
The yoke 62 has a cut-out portion 62d formed at a portion straddling each leg piece 62b and the center piece 62c.
At the center of the edge of the upper edge of the grid piece 62a, the projecting piece 6
2e is formed.

When the cover 12 is covered on the body 11 with the yoke 62 mounted on the body 11, the positioning projections 12b are inserted into the notches 62d of the yoke 62, and the positioning projections 12b are positioned on both sides of the projection 62e. The side surface of 12c contacts the edge of the central piece 62c. Also, the positioning piece 12c
Abuts on the protruding piece 62e. Therefore, the movement of the yoke 62 in the direction along the line of intersection between the leg piece 62b and the center piece 62c is restricted by the positioning pieces 12b and 12c.
Further, as described above, since the holding pieces 12a abut on both leg pieces 62b of the yoke 62, the yoke 62 is
The movement of the yoke 62 in the direction connecting the two leg pieces 62b is also restricted. Here, since the positioning pieces 12b and 12c are provided on both sides in the thickness direction of the holding piece 12a, the rotational movement of the yoke 62 about the contact portion of the holding piece 12a is also restricted. As described above, when the cover 12 is covered on the body 11, the yoke 62 is fixed by the cover 12, so that the yoke 62 does not vibrate even if the magnetic field generated around the contact device fluctuates, and the growl is reduced. You can do it.

Next, the leakage current detecting device 30 will be described. The leakage current detection device 30 drives the trip device 50 by determining an abnormal current when an unbalanced current flows in the main circuit, and as shown in FIG.
a, 23b, and 23c, the main body 31 having the zero-phase current transformer 32 for detecting that an unbalanced current has flowed, and the interlocking bar 47 when the unbalanced current is detected, is rotated counterclockwise in FIG. Drive unit 33 having solenoid 34 for rotating
It is composed of

The main unit 31 is a circuit composed of a printed wiring board on which a zero-phase current transformer 32 and electronic components constituting an electronic circuit unit for detecting an unbalanced current by the secondary output of the zero-phase current transformer 32 are mounted. The substrate is formed in the sensor case 37. The sensor case 37 is formed by connecting a case body 37a and a case cover 37b. Sensor case 37
An opening window 37c is formed coaxially with the center hole of the zero-phase current transformer 32 so as to open circularly and penetrate the sensor case 37.

The conductors 23a, 23b and 23c are inserted through the opening window 37c, as shown in FIG.
Each of the conductors 23a, 23b, 23c is bent in a substantially U-shape. Further, a pair of insulating separators 81 and 82 made of synthetic resin are attached to the sensor case 37 so that the circuit conductors 23a, 23b and 23c do not come into contact with each other at a portion where the current transformer 32 is inserted. Is done. Each insulating separator 81, 82
Are the main plates 81a, 8 facing the outer surface of the sensor case 37.
2a and separation pieces 81b, 8 inserted into the zero-phase current transformer 32.
2b are continuously and integrally provided. Mounting projections 81c and 82c having a bulging tip protrude from surfaces of the main pieces 81a and 82a facing the sensor case 37, and mounting projections 81c and 82c are formed in mounting holes 37h provided in the sensor case 37.
By press-fitting c, the insulating separators 81 and 82 are fixed to the sensor case 37. That is, the mounting projection 81
An uneven engagement means is formed by c and 82c and the mounting hole 37h. The separation piece 81b of the insulating separation body 81 is formed in a cross-sectional shape in which a pair of U-shapes are back to back and a narrow slit 81d is formed therebetween. The separating piece 82b of the insulating separator 82 is formed in a substantially U-shaped cross section opened downward, and has a shape provided with a protruding piece 82d inserted into the slit 81d of the separating piece 81b on the upper surface of the central piece of the U-shape. It is formed. That is, the two insulating separators 81 and 82 are positioned by the engagement between the slit 81d and the protruding piece 82d. In addition, each of the conductors 23a, 23b, and 23c is disposed inside the groove, which is a U-shaped portion of each of the separation pieces 81b and 82b, so that each of the conductors 23a, 23b, and 2 is provided.
3c are insulated from each other.

On the other hand, the driving section 33 has a sub case 71 connected to the case body 37a. The sub case 71 houses a circuit board on which a test switch 72 for performing an operation test together with the solenoid is mounted, and a display button 7 protruding from the upper surface of the body 10 when the solenoid is operated.
4 are also provided. Further, a slide switch for switching the sensitivity for operating the solenoid with respect to the unbalanced current is mounted on the circuit board. The display button 74 is engageable with the plunger 34a when the plunger 34a of the solenoid is protruding.
And the upper surface of the container 10 are substantially flush. Further, when the engagement with the plunger 34a is released in the state of engagement with the plunger 34a, the push-up spring 76 pushes the same upward and projects from the upper surface of the container 10.

The test switch 72 includes a contact piece 72 a forming a contact portion and an operation button 7 protruding from the upper surface of the body 10.
When the operation button 72b is pushed into the body 10, when the operation button 72b is pushed into the body 10, a current flows through the test winding wound around the zero-phase current transformer by one turn, and the secondary output similar to that at the time of occurrence of the unbalanced current is reduced to zero. In a phase transformer. Therefore, if the operation button 72b of the test switch 72 is pressed in a state where the display button 74 is reset so as to be engaged with the plunger 34a, a test as to whether or not the leakage current detection device 30 functions normally can be performed.

The tip of the solenoid plunger 34a is inserted into a catch groove 47d provided in the interlocking bar 47, and when the plunger 34a is retracted, the catch pin 34b projecting from the tip of the plunger 34a is engaged with the catch groove 47d. The interlocking bar 47 is rotated in contact with the peripheral edge. That is, the pull-in of the plunger 34a also rotates the interlocking bar 47 to operate the trip device 50.

[0042]

According to the structure of the first aspect of the present invention, the yoke having the central piece bridging one end of the pair of leg pieces is attached to the cover so as to contact the outer surfaces of both leg pieces of the yoke. The yoke is fixed by being clamped by the provided clamping pieces, so that the direction of action of the force for clamping the yoke is substantially orthogonal to the direction of covering the cover on the body. No reaction force is received from the yoke. That is, the possibility of breakage of the cover is reduced. In addition, since a separate member such as an elastic material is not required, the assembling work is easy and can be realized at low cost. Moreover, even when a current flowing through the contact device arranged near the yoke contains a harmonic component, the yoke can be held down to suppress the vibration of the yoke and prevent growling.

According to the configuration of the second aspect of the present invention, the yoke moves in this direction by providing the positioning means for restricting the movement of the yoke in the direction along the intersection line between the leg piece and the center piece. In addition to the fact that the movement in the direction connecting the two leg pieces is restricted by the holding piece, the yoke can be firmly fixed. As a result, it is possible to further suppress rattling of the yoke and prevent groaning.

According to a third aspect of the present invention, there is provided the configuration of the second aspect of the present invention, wherein two sets of positioning projections are provided on the cover, and one set is inserted into a notch provided on the yoke. Since the other set is brought into contact with the end face of the yoke, it is possible to reliably restrict the movement in the direction along the line of intersection between the leg piece and the center piece. Moreover, since the two sets of positioning projections are provided on both sides of the holding piece, the yoke does not rotate around the contact portion with the holding piece as a fulcrum, and the yoke can be securely fixed with a simple configuration. .

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a main part of an embodiment.

FIG. 2 is a longitudinal sectional view of a main part of the embodiment.

FIG. 3 is a bottom view of a main part of the embodiment.

FIG. 4 is an exploded perspective view of a main part of the embodiment.

FIG. 5 is a perspective view of the embodiment.

FIG. 6 is an exploded perspective view of the embodiment.

FIG. 7 is an exploded perspective view of a main part of the embodiment.

FIG. 8 is an exploded perspective view of a main part of the embodiment.

FIG. 9 is a cross-sectional view of the embodiment in a closed state.

FIG. 10 is a cross-sectional view of the embodiment in an opened state.

FIG. 11 is a cross-sectional view showing a state immediately after a trip operation of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Body 11 Body 12 Cover 12a Holding piece 12b, 12c Positioning protruding piece 14 Power supply side terminal board 14a Main piece 14b Vertical piece 14c Contact support piece 21 Fixed contact 25 Movable contact 26 Movable contact 62 Yoke 62b Leg piece 62c Central piece 62d Notch

Continuing from the front page (72) Inventor Kazuharu Sonoda, Mie Pref., 564, Oji Handa, Mie Pref. Mie Metal Industry Co., Ltd. (56) References JP-A-63-81712 (JP, A) JP-A-5-90785 (JP, U) JP-A-2-1847 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01H 73/18 H01H 73/06

Claims (3)

(57) [Claims] 1. A housing comprising a body having an open surface and a cover which is covered by the opening of the body, and a contact support piece fixed to a fixed position of the body and having fixed contacts provided on one surface of the cover. A fixed contact provided with a drive coil disposed on at least one side of the contact; a movable contact provided with a movable contact separated from and brought into contact with the fixed contact; and a pair of leg pieces disposed on both sides of the fixed contact. A yoke made of a magnetic material having a central piece bridging between the cover-side ends of the two leg pieces, and a drive coil is arranged between the fixed contact and the yoke leg pieces and connects the two leg pieces of the yoke. An arc extinguishing device is provided in which a magnetic field in the direction is formed near the fixed contact so that the arc formed between the fixed contact and the movable contact and the magnetic field interact with each other to urge and extend the arc. For switches A switch provided with an arc extinguishing device, characterized in that the cover is provided with a pair of holding pieces for holding the yoke in contact with the outer surfaces of both leg pieces of the yoke. 2. The arc extinguishing device according to claim 1, wherein the yoke and the cover are provided with positioning means for restricting movement of the yoke in the direction along the line of intersection between the leg piece and the center piece. A switch comprising: 3. The positioning means includes a notch formed so as to straddle the center piece and the leg piece in the yoke, and each holding piece in a direction along an intersection line between the leg piece and the center piece of the yoke in the cover. And two sets of positioning projections provided on both sides of the yoke. One set of positioning projections is inserted into the notch, and the other set of positioning projections has side faces on the yoke with a center piece and a leg piece. The switch provided with the arc extinguishing device according to claim 2, wherein the switch is in contact with one surface straddling the following.