JPH0917315A - Circuit braker - Google Patents

Abstract

PURPOSE: To secure reliable and stable insulation by preventing dielectric breakdown by gas and a melted material or the like generated by an arc. CONSTITUTION: Insulating side plates 73 of a grid device 72 are arranged by leaving a space δB to a fixed side arc traveling plate 71. Projections 100 which are protrusively arranged from an apparatus body 10 and are composed of an insulating material, are interposed between the insulating side plates 73 and the fixed side arc running plate 71. The space δB between the fixed side arc running plate 71 and arc-extinguishing magnetic plates 74 in close vicinity to this, is made wider than respective intervals δA between the plural arc- extinguishing magnetic plates 74.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker for breaking a circuit when an overcurrent such as an overload current or a short circuit current occurs.

[0002]

2. Description of the Related Art Generally, in this type of circuit breaker, a movable contactor, which is opened and closed by a handle operation and is forcibly driven to open in response to an abnormal current, is provided in the body of the circuit breaker. A fixed contact having a fixed contact attached to and separated from a contact provided on the tip of the movable contact facing the child, and from the tip of the fixed contact electrically connected to the fixed contact. Between the extending fixed side arc traveling plate, the movable side arc traveling plate disposed facing the fixed side arc traveling plate and electrically connected to the movable contact, and between the movable side and the fixed side arc traveling plate. And a grid device in which a plurality of arc-extinguishing magnetic plates interposed between the movable side and fixed side arc traveling plates are housed, respectively, and the arc device generated by the insulating side plate is held at intervals. The arc is extinguished by dividing it with multiple arc extinguishing magnetic plates. It is known.

The basic structure of this circuit breaker is shown in FIGS.
This will be described with reference to FIG. As shown in FIG. 2, the body 10 of the circuit breaker is made of an insulating material such as synthetic resin, and a power source side terminal 20a and a load side terminal 20b are provided on each side. A terminal plate 21a having a fixed contact 31 (see FIG. 3) is electrically connected to the power source side terminal 20a, and a terminal to which one end of a bimetal 61 constituting the thermal dynamic release device 60 is fixed is fixed to the load side terminal 20b. The plate 21b is electrically connected. The fixed contact 31 constitutes the contact portion 30 together with the movable contact 32 provided on the movable contact 33, and the movable contact 33 is brought into contact with or separated from the fixed contact 33 in accordance with the operation of the opening / closing device 40 described later. The movable contact 33 is a connecting wire 3 made of a braided wire.
7 is electrically connected to one end of a coil 51 of an electromagnetic release device 50, which will be described later, and the other end of the coil 51 is connected to an intermediate portion of a bimetal 61 via a connecting wire 38 made of a braided wire. Therefore, when the contact portion 30 is closed, the power source side terminal 20a-contact portion 30-coil 51-bimetal 61.
A main electric path through which a current flows is formed by the path of the load side terminal 20b. Here, as the bimetal 61,
Either a direct heating type, which bends by self-heating, or an indirectly heating type, in which plate-shaped heaters are stacked and bends by heating by the heater, may be used.

As shown in FIG. 4, the body 10 is a body 1.
0a and the cover 10b are joined together by using a rivet 11. That is, the body 10a and the cover 10b are provided with the assembly holes 12a and 12b at four positions on the peripheral portion,
The body 10a and the cover 10b can be coupled by passing the rivets 11 through the assembly holes 12a and 12b, respectively. The body 1 is on the upper surface of the body 10.
A handle insertion hole 13 that opens in a rectangular shape when the 0a and the cover 10b are abutted is formed. As shown in FIG. 3, the handle insertion hole 13 is located inside the body 10a and the cover 10b and near the handle insertion hole 13. A cylindrical bearing 14 is provided so as to project. In the bearing hole 14a opening in the center of the bearing 14,
Each end of the handle shaft 42 that supports the handle 41 is inserted. The handle 41 is provided with an operation portion 41 a that projects to the upper surface of the body 10 through the handle insertion hole 13. That is, the handle 41 is rotatable about the handle shaft 42 within a range in which the operation portion 41 a can move in the handle insertion hole 13. An arcuate cover piece 41b centering on the handle shaft 42 is provided at the base of the operating portion 41a of the handle 41.
Is formed, and the peripheral portion of the handle insertion hole 13 in the body 10 bulges outward along the cover piece 41b.
Since the cover piece 41b is in sliding contact with the inner side surface of the body 10, the cover piece 41b shields the inside of the body 10 from being visible even when the handle 41 is rotated, and the cover piece 4b.
Characters indicating the opening and closing of the contact portion 30 according to the operation of the handle 41 are written on 1b. A link support portion 41c is provided on the lower surface of the cover piece 41b, and shaft protrusions 41d are provided on both lower side surfaces of the link support portion 41c. Here, the operating portion 41a and the link supporting portion 41c are set so that the projecting directions with respect to the covering piece 41b are set so that they are not in a straight line and have a substantially V-shaped cross section. Further, the handle 41 is biased counterclockwise in FIG. 3 by a handle return spring 43, which is a scissor-shaped spring mounted around the bearing 14. That is, one end of the handle return spring 43 is locked to the right end of the cover piece 41b in FIG. 2, and the other end is locked to the trip plate 44 of the opening / closing device 40 described later.

The opening / closing device 40 is formed in a substantially U-shape, and the handle 4 is inserted into a bearing hole 45a formed at the tip of each leg.
1. The handle link 4 into which the shaft protrusion 41d provided in 1 is inserted
5 and a pair of guide pieces 46b extending substantially in a direction substantially orthogonal to the locking plate 46a and extending along the edge of the locking plate 46a at both ends of the flat plate-shaped locking plate 46a. The latch plate 46 in which the handle shaft 42 is inserted into the formed shaft hole 46c, and the bearing holes 15a provided in the bearings 15 formed in the inner surfaces of the body 10a and the cover 10b, which are inserted into the trip plate 44, are provided at respective ends of the bearing holes 15a. Part is inserted and trip plate 4
4. A shaft pin 47 for rotatably supporting 4 with respect to the body 10.
And one leg piece 48a formed in a substantially U shape has a latch plate 46
And a contact link 48 which is inserted into a link hole 45c provided at the base of both leg pieces of the handle link 45 through guide holes 46d formed in both guide pieces 46b. The other leg piece 48b of the contactor link 48 is inserted into a shaft hole 33a provided in the movable contactor 33. Here, an arcuately curved guide groove 16 convex downward in FIG. 3 is formed on the inner surface of the body 10a, and the tip end portion of the leg piece 48b of the contactor link 48 is inserted into this guide groove 16. The movement range of the contact link 48 is restricted by the guide groove 16.

The movable contact 33 has a movable contact 32 at one end.
And a spring receiving piece 33b at the other end,
It is formed in a shape having a bearing piece 33c having an opening of a shaft hole 33a into which a leg piece 48b of a contact link 48 is inserted, at a portion between the movable contact 32 and the spring receiving piece 33b. Here, one end of the movable contactor 33 formed of a plate material is bent into a substantially L shape and the corner portion is used as the movable contact 32. The arc running piece 33d is extended. A spring seat 33e (see FIG. 5) inserted into one end of a contact pressure spring 34 made of a coil spring is provided on the spring receiving piece 33b so as to project therefrom. Further, the other end of the contact pressure spring 34 is connected to the body 10 on one side.
It is housed in a spring receiving recess 35 formed on the inner surface of a. A stopper 36 is provided on the inner surface of the body 10a so as to face the opening surface of the spring receiving recess 35, and the space between the inner surface of the body 10a in which the spring receiving recess 35 is formed and the stopper 36 is formed. The contact pressure spring 34 and the spring receiving piece 33
b is inserted, and the spring force of the contact pressure spring 34 urges the spring receiving piece 33b toward the stopper 36.

The trip plate 44 has a first pressing piece 44b projecting from the upper end of the base piece 44a to one side and a base piece 4a.
The second pressing piece 44c extends downward from 4a,
Further, the arm piece 44d is formed to project from one side edge of the base piece 44a in the upper and lower intermediate portions in a direction substantially orthogonal to the base piece 44a. A shaft pin 47 is provided at the base of the arm piece 44d.
And the trip plate 44 is rotatable around the shaft pin 47. Further, a hooking groove 44e is formed on the upper edge of the tip end of the arm piece 44d, and the upper edge of the arm piece 44d is inclined so that the upper edge of the arm piece 44d becomes closer to the lower edge on the tip side of the hooking groove 44e. Further, a locking recess 44f having a shape that is opened laterally and cut upward is formed at a side edge of the base piece 44a, and one end of the handle return spring 43 is locked in the locking recess 44f. By doing so, the trip plate 44 is biased counterclockwise in FIG.

The latch plate 46 is rotatable with respect to the body 10 together with the handle 41 by the handle shaft 42, but the leg piece 48a of the contactor link 48 inserted into the handle link 45 is the latch plate 46. Since the handle link 45 is inserted into the guide hole 46d and is pivotally supported by the shaft protrusion 41d of the handle 41,
The swing range of the latch plate 46 with respect to 1 is restricted.
Further, the lower edge of the locking piece 46a of the latch plate 46 can be engaged with the hooking groove 44e provided in the trip plate 44, and the movement of the latch plate 46 is prohibited in the engaged state.

As described above, the handle 41 and the handle shaft 4
2, handle return spring 43, trip plate 44, handle link 45, latch plate 46, shaft pin 47, contactor link 4
In the switchgear 40 configured by 8, when an excessive current passes through the main circuit in the closed state of the contact portion 30,
It functions to open the contact portion 30 by the operation of the electromagnetic release device 50 or the thermal release device 60.

The electromagnetic release device 50 is provided with a yoke (movable side arc traveling plate) 52 formed of a magnetic material in an approximately U-shape that is opened upward, and the coil 5 is provided in the inner space of the yoke 52.
1 is stored. That is, the yoke 52 is the coil 51.
Of the pair of side pieces 52 respectively facing both axial end faces of the
a, 52b, and the side pieces 52 passing under the coil 51
and an intermediate piece 52c connecting between a and 52b. In addition, holding grooves 52d and 52e that are open to the side are formed in the side pieces 52a and 52b. The coil 51 is wound around the outer circumference of a cylindrical coil tube 53 made of an insulating material, and a flange 53a is integrally formed at one end portion of the coil tube 53 in the axial direction. A tapered portion 53b having an inner diameter and an outer diameter smaller than that of the axially intermediate portion is formed at the other end of the.

A tapered portion 53b is provided in the inner space of the coil tube 53.
A movable iron core 54 having a portion having a diameter larger than the inner diameter of the coil barrel 53 is installed so as to be movable in the axial direction of the coil barrel 53, and the movable iron core 54 is attached to the end of the coil barrel 53 on the flange 53a side. The fixed iron core 55 facing the coil coil 5 partially
The coil tube 53 is attached to the coil tube 53 so as to protrude from the coil tube 3. A hooking pin 54a is integrally provided on one end surface in the moving direction of the movable iron core 54 so as to project from the end surface of the coil cylinder 53 on the side of the tapered portion 53b.
The pressing pin 57 protruding from the end surface of the flange 53a side is fixed. A hooking head 54b having a larger diameter than other parts is formed at the tip of the hooking pin 54a. A return spring 56 composed of a coil spring is interposed between the movable iron core 54 and the fixed iron core 55.
The movable iron core 54 is urged toward the tapered portion 53a side of the coil cylinder 53 by the spring force.

Both ends in the moving direction of the movable iron core 54 are formed to have a smaller diameter than the middle part, one end serves as a spring receiving portion 54c to be inserted into the return spring 56, and the other end is a tapered portion 53b of the coil cylinder 53. Is formed so that it can be inserted into the inside of the taper, and the intermediate portion has a diameter larger than the inside diameter of the tapered portion. That is, the retaining step 54d is formed between the small diameter portion and the large diameter portion of the movable iron core 54 where the hooking pin 54a is provided so as to project,
The movable iron core 54 is prevented from falling off by locking the retaining step 54d to the step formed between the intermediate portion and the tapered portion 53b on the inner circumference of the coil tube 53.

The fixed iron core 55 has one end near the movable iron core 53 in the axial direction of the coil cylinder 53 formed to have a smaller diameter than the other parts, and is inserted into the return spring 56.
The outer flange 55b having a diameter larger than those of the other parts is formed at the other end. Further, a coupling protrusion 55c is provided at the center of the other end. However, if the fixed iron core 55 is inserted into the flange 53a side of the coil cylinder 53, the outer flange piece 55c abuts on the end surface of the coil cylinder 53, and the coupling protrusion 55c is formed.
Will project from the coil tube 53. Further, the pressing pin 57 fixed to the movable iron core 54 is inserted into the insertion hole 55d penetrating the fixed iron core 55 in the axial direction,
It projects from the coil tube 53.

In the core member formed by mounting the movable iron core 54, the fixed iron core 55, and the return spring 56 on the coil cylinder 53 as described above, the tapered portion 53b of the coil cylinder 53 is formed on the side piece 52a of the yoke 52. The holding groove 52d which is fitted in the holding groove 52d provided in the
It is attached to the yoke 52 by being fitted in e. Here, the side piece 52 of the coil 51 and the yoke 52
The flange 53a of the coil tube 53 is interposed between the coil 51 and the coil b, so that insulation between the coil 51 and the side piece 52b of the yoke 52 is ensured. Also, the coupling protrusion 5
5c is fitted in the holding groove 52e provided in the side piece 52b of the yoke 52, and the outer flange piece 55b is sandwiched between the flange 53a of the coil cylinder 53 and the side piece 52b.
The fixed iron core 55 is magnetically coupled to the yoke 52.

An electromagnetic release device 50 constructed as described above.
Are holding projections 17a, 17 protruding from the inner surface of the body 10a with respect to the holding grooves 52d, 52e formed in the yoke 52.
By inserting b, the body 10a is fixed at a fixed position. In addition, the holding protrusion 17 is provided on the inner surface of the body 10a.
yoke mounting grooves 18a, 1 formed near a, 17b
The yoke 52 is also fixed to the body 10a by fitting the side piece 52a of the yoke 51 to the 8b. When the yoke 52 is fixed to the body 10a, the tapered projection 53b of the coil tube 53 and the coupling projection 55c of the fixed iron core 55 are respectively formed between the inner peripheral edges of the holding grooves 52d and 52e and the tip edges of the holding projections 17a and 17b. It is sandwiched between them, and the coil cylinder 53 is fixed to a fixed position with respect to the yoke 52.

In the electromagnetic release device 50 having the above-described structure, when the coil 51 is energized, it is fixed to the movable iron core 54 so as to reduce the magnetic resistance of the magnetic path passing through the fixed iron core 55-yoke 52-movable iron core 54. If the passing current to the coil 51 is an excessive current such as when the load is short-circuited, the movable iron core 55 resists the spring force of the return spring 56. 54 is moved so as to approach the fixed iron core 55. Therefore, when operated in this way, the switchgear 4
By operating 0, the contact part 30 in the closed state can be forcibly opened, and is connected to the switchgear 40 as follows.

That is, the tip of the hooking pin 54a provided on the movable iron core 54 has a shaft hole 33a in the movable contact 33.
Hole 3 formed in a portion between the movable contact 32 and the movable contact 32.
3e, and when the movable iron core 54 is attracted by the excitation of the coil 51 so as to approach the fixed iron core 55, the hooking head 54b provided at the tip of the hooking pin 54a.
Is engaged with the peripheral portion of the hooking hole 33e and pulls the movable contact 33 in the direction of separating from the fixed contact 31. Here, the hooking hole 33e is formed in the shape of a bear by connecting a locking hole having a diameter smaller than that of the hooking head 54b and an introduction hole having a diameter larger than that of the hooking head 54b. The electromagnetic releasing device 50 can be easily coupled to the movable contact 33 by introducing the hooking pin 54a into the locking hole after passing through.
Further, the tip of the pressing pin 57 fixed to the movable iron core 54 is positioned so as to face the second pressing piece 44c of the trip plate 44, and when the movable iron core 54 is attracted to the fixed iron core 55 and moves, The trip plate 44 is rotated around the shaft pin 47 in the clockwise direction in FIG.

On the other hand, the thermal release device 60 is provided with the bimetal 61 as described above, one end of the bimetal 61 is fixed to the terminal plate 21b described later, and the other end is inserted in the bending direction of the bimetal 61. The adjusting screw 62 is screwed.
The adjusting screw 62 faces the first pressing piece 44b of the trip plate 44, and the bimetal 6 is caused by an excessive current passing through the main circuit.
When 1 is curved, the trip plate 44 is pushed by the tip of the adjusting screw 62, so that the trip plate 44 is moved to the shaft pin 47.
It is adapted to rotate clockwise around in FIG.

An adjusting window 63 is opened in the vicinity of the adjusting screw 62 screwed into the bimetal 61 on the peripheral wall of the body 10. The adjustment window 63 has an insertion portion 63a formed at the upper end portion so as to be wider than other portions, and the upper edge of the adjustment window 52 is a guide surface 63b inclined downward toward the inside of the body 10. There is. Further, on both sides of the adjusting window 63, a mounting groove 63c is formed, the upper end of which is continuous with the insertion portion 63a and the lower end of which extends to the lower end of the adjusting window 63. That is, the adjustment window 63
Guide ribs 63d reaching the lower end of the adjustment window 63 are formed on both side surfaces of the body 10 while leaving the insertion portion 63a on the outer side of the body 10, and the upper and lower entire lengths of the adjustment window 63 are formed on the inner side of the body 10. By forming the guide rib 63e, the mounting groove 63c is formed between the guide ribs 63d and 63e.

The degree of bending (operation sensitivity) of the bimetal 61 with respect to the passing current varies depending on the variation of the material of the bimetal 61 and the connecting position of the connecting wire 38. Therefore, the operation sensitivity of the switchgear 40 (that is, the switchgear). 40
In order to prevent variations in the passing current of the main electric path when the electric motor operates, adjust the amount of protrusion of the adjusting screw 62 screwed into the bimetal 61 from the bimetal 61 to the trip plate 44 side. Will be required. Therefore, after the assembly, the adjusting screw 62 is operated with the adjusting window 63 opened. On the other hand, after adjusting the adjusting screw 62 once,
Since it is not necessary to operate the adjusting screw 62, the insertion portion 63a
The flexible closing plate 64 is dropped into the mounting groove 63c through the closing groove 63c to close the adjusting window 63 to inadvertently operate the adjusting screw 62 or foreign matter enters the body 10. Try not to do anything. The closing plate 64 is set to be substantially equal to the width of the adjustment window 63 (distance between the bottoms of the mounting grooves 63c) and substantially equal to the height dimension of the adjustment window 63 in the vertical direction. Such a closing plate 64
When is attached to the adjusting window 63, the upper end of the closing plate 64 contacts the upper surface of the adjusting window 63, and the closing plate 64 cannot be removed.

By the way, the power supply side terminal 20a and the load side terminal 20b are formed by bending a conductive metal plate into a substantially square cross section, and a tightening screwed into the upper piece of the terminal metal fitting 22. The screw 23 and the terminal plates 21a and 21b which contact the lower end of the tightening screw 23 are provided. The terminal fitting 22 is a terminal storage chamber 24 formed in the body 10 and having a rectangular horizontal cross section.
It is stored in a and 24b so as to be movable up and down. That is, the terminal housing chambers 24a and 24b are the terminal fittings 2
The height of the terminal fitting 22 is larger than that of the terminal fitting 2, and the terminal fitting 22 is prevented from rotating in the terminal accommodating chambers 24a and 24b and is movable only in the vertical direction. The head of the tightening screw 23 is formed in a truncated cone shape whose upper portion has a smaller diameter than that of the lower portion.
A screw operation hole 25 having a diameter such that a part of the head of the tightening screw 23 can be inserted and the head of the tightening screw 23 does not pass through is formed in the upper walls of 4a and 24b. The diameter of the upper part of the screw operation hole 25 is the tightening screw 23.
Is smaller than the upper end of the head, and the diameter of the lower part of the screw operation hole 25 is set larger than the lower end of the head of the tightening screw 23. The tips of the terminal plates 21a and 21b are the body 1
0 is exposed on the outer side surface and is bent upward,
The terminal plate 21 with respect to the fixing groove 26 formed on the outer surface of the
By engaging the fixed projecting piece 21c formed at the tip end portions of the a and 21b, the vertical movement of the tip end portions of the terminal plates 21a and 21b is prohibited. Furthermore, the terminal storage chamber 24a,
Terminal storage chamber 24 for partitioning 24b and the internal space of the body 10
Terminal plate holding grooves 27 for positioning the terminal plates 21a and 21b are formed on the side walls of a and 24b.
The vertical movement of the terminal plates 21a, 23b is also prohibited by inserting a part of the terminal plates 21a, 21b into the.
That is, in the terminal plates 21a and 21b, the tightening screw 2
Since vertical movement is prohibited on both sides of the part that abuts on the terminal 3, even if an external force acts from the tightening screw 23, the terminal plate 21
The a and 21b are fixed in place. Here, the terminal boards 21a and 21b and the terminal storage chambers 24a and 24b
The distance from the upper wall is set to be substantially equal to the length dimension of the tightening screw 23.

However, when the tip of a flat-blade screwdriver is inserted into the screw operation hole 25 and the tightening screw 23 is rotated, the terminal fitting 22 is rotated depending on the rotating direction of the tightening screw 23.
Moves up and down, the distance between the lower piece of the terminal fitting 22 and the terminal plates 21a, 21b can be changed. That is, the lower walls of the terminal storage chambers 24a and 24b and the terminal board 21
A wiring member such as an electric wire or a bus bar is inserted into the connection hole 28 penetrating the peripheral wall of the body 10 corresponding to a portion between the terminals a and 21b, and the tightening screw 23 is rotated to rotate the terminal. By bringing the lower piece of the metal fitting 22 close to the terminal plates 21a, 21b, the wiring member is sandwiched between the terminal metal fitting 22 and the terminal plates 21a, 21b, and the electrical connection with the wiring member can be made.

Terminal plate 21a constituting the power supply side terminal 20a
Has a fixed contact 39 that is bent downward on the inner side of the body 10 with respect to the terminal plate holding groove 27, and a fixed contact 31 is fixed to the lower end of the fixed contact 39. The movable contact 32 provided on the movable contact 33 faces the fixed contact 31. Further, in the fixed contactor 39, below the fixed contact 31, a part of the fixed side arc traveling plate 71 made of a conductive plate is superposed on the surface where the fixed contact 31 is projected. The stationary arc traveling plate 71 includes a vertical guide piece 71a that partially overlaps with the fixed contact 39, and the lower end of the guide piece 71a has a bottom wall of the body 10 via an inclined piece 71b that is inclined obliquely downward. Along with the arc extinguishing piece 71c extending below the intermediate piece 52c of the yoke 52. Here, the grid device 72 is arranged between the opposing portions of the intermediate piece 52c of the yoke 52 and the arc extinguishing piece 71c. The grid device 72 has a configuration in which a plurality of arc-extinguishing magnetic plates 74 made of a conductive plate are held inside a substantially U-shaped insulating side plate 73 made of an insulating material. Has a notch 74a into which the lower end of the movable contact 33 is introduced. In this grid device 72, the arc-extinguishing magnetic plate 74 includes an intermediate piece 52b of the yoke 52 and an arc-extinguishing piece 71c of the stationary-side arc traveling plate 71.
Are arranged so as to be substantially parallel to.

Further, a mounting rail (so-called DIN rail) arranged inside the distribution board or the like is provided on the lower surface of the body 10.
A mounting device for removably fixing to 80 (see FIG. 4) is provided. The mounting rail 80 has a shape in which a brim piece 80a is integrally projecting outwardly over the entire length at the tip edges of both leg pieces of the rail body formed in a substantially U-shaped cross section. A mounting recess 81 that is orthogonal to the direction connecting the power supply side terminal 20a and the load side terminal 20b is formed on the lower surface of the body 10, and one side wall of the mounting recess 81 has an inner bottom surface of the mounting recess 81. A locking projection 82 into which one flange piece 80a of the mounting rail 80 is inserted is provided in a protruding manner. Also, the mounting recess 81
A through hole 83 passing through the outer side surface of the body 10 is formed on the other side surface of the body 10, and a mounting claw 84 is inserted into the through hole 83. The mounting claw 84 is provided with a claw part 84b projecting into the mounting recess 81 at the other end of a rectangular frame-shaped frame part 84a having one end projecting from the outer surface of the body 10, and the claw part 84a is provided in the frame part 84a. A spring piece 84c is provided in which one end on the side of the portion 84b is integrally connected to the frame portion 84a and the other end is a free end. Spring piece 8
4c is formed in a wavy shape that repeats unevenness in the direction of the center line of the through hole 83, and the free end is locked to the stepped portion 83a formed on the inner peripheral surface of the through hole 83, whereby the claw portion 84 is formed.
The mounting claw 84 is biased in such a direction as to project b into the mounting recess 81. Further, the claw portion 84b is formed with a movement restricting step portion 84d that is locked by a locking step portion 83b formed on the inner peripheral surface of the through hole 83, and the movement restricting step portion 84d attaches a mounting recess of the mounting claw 84. The amount of protrusion to 81 is restricted. Here, the claw portion 84b is formed in a shape capable of sandwiching the other flange piece 80a of the mounting rail 80 with the inner bottom surface of the mounting recess 81. Further, the lower surface of the claw portion 84b is an inclined surface 84e which is inclined upward toward the tip.

Therefore, one flange piece 80 of the mounting rail 80
When the body 10 is pressed against the mounting rail 80 in a state in which a is inserted between the inner bottom surface of the mounting recess 81 and the locking projection 82, the other flange piece 80a of the mounting rail 80 extends from the inclined surface 84e. When the attachment claw 84 is pushed in a direction projecting from the body 10 by the pushing force acting on the claw portion 84b, and the claw portion 84b passes over the tip of the collar piece 80a, the claw portion 8c is pressed by the spring force of the spring piece 84c.
4b protrudes into the mounting recess 81, and between the inner bottom surface of the mounting recess 81 and the claw portion 84b, the other flange piece 8 of the mounting rail 80 is provided.
0a is retained. In this way, the body 10 can be fixed to the mounting rail 80. On the other hand, body 1
To remove 0 from the mounting rail 80, the tip of a flat-blade screwdriver or the like is inserted into the frame portion 84a protruding on the side surface of the body 10 and the mounting claw 84 is pulled out from the body 10. Claw portion 8 for the collar piece 80a of
The engagement state of 4b is released, and the body 10 is attached to the mounting rail 80.
Can be removed from the.

Next, the operation of the circuit breaker will be described. FIG. 5 shows a closed state of the contact portion 30, and a handle 41
The operating portion 41a of the above is tilted rightward around the handle shaft 42. At this time, the trip plate 44 moves the handle return spring 4
The spring force of 3 urges the shaft pin 47 in the counterclockwise direction around the shaft pin 47 to move the adjustment screw 62 provided on the bimetal 61 to the first position.
The pressing piece 44b is kept in contact. Further, the spring force of the contact pressure spring 34 acts on the latch plate 46 via the movable contact 33 and the contact link 48, and the contact link 48.
Since the distance between the leg piece 48a of the above and the shaft protrusion 41d provided on the handle 41 is restricted by the handle link 45, the latch plate 46 receives the spring force of the contact pressure spring 34 and rotates counterclockwise around the handle shaft 42. Be urged by. Therefore, the locking piece 46a of the latch plate 46 engages with the locking groove 44e provided in the arm piece 44d of the trip plate 44. That is, since the latch plate 46 tries to rotate clockwise, but the rotation is prohibited by the trip plate 44,
The state of FIG. 5 is maintained. In this state, the position of the latch plate 46 is fixed by the handle shaft 42 and the trip plate 44, and the handle link 45 and the contact link 48.
Will also be fixed in place. As a result, the movable contact 33 is urged counterclockwise by the spring force of the contact pressure spring 34 about the leg piece 48b of the contact link 48. That is, the movable contact 32 comes into contact with the fixed contact 31 with a contact pressure according to the spring force of the contact pressure spring 34. In this state, the positional relationship is set so that the spring receiving piece 33b of the movable contact 33 does not come into contact with the stopper 36 provided on the inner surface of the body 10.

On the other hand, as shown in FIG. 6, when the operating portion 41a of the handle 41 is tilted leftward around the handle shaft 42, the contact portion 30 is opened. That is, the handle 41
By rotating the handle shaft 42 counterclockwise, the upper end of the handle link 45 moves to the right,
An attempt is made to pull up the leg piece 48a of the contactor link 48. However, if the position of the shaft protrusion 41d moves to the right with respect to the straight line connecting the handle shaft 42 and the leg piece 48a,
The spring force of the contact pressure spring 34 acting on the handle link 45 via the movable contact 33 and the contact link 48 acts to further rotate the handle 41 counterclockwise, and the leg piece 48b of the contact link 48 guides. Move to the left along the groove 16. In this way, the leg piece 48 of the contact link 48 is
When b is moved leftward, the spring receiving piece 33b of the movable contactor 33 comes into contact with the stopper 36 provided on the inner peripheral surface of the body 10 by the spring force of the contact pressure spring 34. Here, since the spring force of the contact pressure spring 34 acts below the lower end of the stopper 36, the movable contact 33 is urged clockwise and the movable contact 32 separates from the fixed contact 31. Further, when the contact portion 30 is in the open state, the latch plate 4
6 is restricted by the leg pieces 48a of the handle link 45 and the contact link 48, rotates counterclockwise about the handle shaft 42, and comes off from the trip plate 44.

By the way, in the closed state shown in FIG. 5, when the overload state occurs and an excessive current flows in the bimetal 61 and the bimetal 61 bends, the first tripping plate 44 is bent.
Adjusting screw 62 in which pressing piece 21b is screwed into bimetal 61
The coil 5 due to a short circuit on the load side.
When an excessive current flows through the movable iron core 54 and the movable iron core 54 is attracted to the fixed iron core 55, the second pressing piece 44c of the trip plate 44 is pressed by the pressing pin 57 fixed to the movable iron core. ,
In either case, the trip plate 44 rotates clockwise around the shaft pin 47 as shown in FIG. When the trip plate 44 rotates clockwise, the engagement state with the latch plate 46 is released. In the closed state, the latch plate 46 receives the spring force of the contact pressure spring 34 and the handle shaft 42 moves. Since it is biased clockwise around, the lower end of the latch plate 46 moves to the left. That is, since the leg piece 48b of the contactor link 48, which was the rotation center of the movable contactor 33 in the closed state, moves leftward along the guide groove 16, like the open state shown in FIG. The movable contact 33 is pressed against the stopper 36 by the spring force of the contact pressure spring 34, so that the movable contact 32 separates from the fixed contact 31 and enters the open state. That is, when an excessive current flows in the main circuit, the trip plate 44 rotates and the engagement state with the latch plate 46 is released, and the force that biases the latch plate 46 is released. A so-called trip operation is performed to open the contact portion 30.

By the way, in the conventional grid device 72 ', as shown in FIG. 8, for example, as shown in FIG.
The insulating side plate 73 of the grid device 72 'is placed in direct contact with the inside of the bodies 10a and 10b.

[0030]

However, in the conventional structure in which the fixed side arc traveling plate 71 is directly contacted with the insulating side plate 73 of the grid device 72 ', an arc is generated and the arc traveling plate is moved. Ark runs, grid device 7
When the arc is divided and extinguished by 2 ', a melt may be generated due to the heat of the arc and adhere between the arc extinguishing magnetic plates 74 of the grid device 72', and the insulating side plate 73 is particularly likely to become a gas retention part. Soot may adhere to the corners of the. Therefore, the insulation between the arc-extinguishing magnetic plate 74 close to the fixed-side arc traveling plate 71 and the fixed-side arc traveling plate 71 deteriorates due to soot adhering to the corners of the insulating-side plate 73, and is further generated by arc heat. Grid device 72 'due to melted material
Since the melted material is clogged between the plurality of arc-extinguishing magnetic plates 74 and between the arc-extinguishing magnetic plate 74 and the fixed-side arc traveling plate 71 to deteriorate the insulation state, it is possible to secure the insulation state after the circuit is cut off. It will be difficult. Here, in particular, in the grid device 72 ', since the arc invasion on the stationary arc traveling plate 71 side is faster than that on the movable arc traveling plate 52 side, the above phenomenon is likely to occur, and the stationary arc traveling plate 71 side is insulated. Is often a problem.

The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to prevent a dielectric breakdown due to a gas or a melt generated by an arc, and to ensure a reliable and stable insulation. It is possible to provide a circuit breaker.

[0032]

In order to solve the above-mentioned problems, the present invention relates to a movable contact 33 which is opened and closed by a handle operation and is forcibly driven to open in response to an abnormal current, and this movable contact. A fixed contact 39 having a fixed contact 31 that comes into contact with and separates from a contact portion 30 provided at the tip of the movable contact 33 facing the 33, and a fixed contact electrically connected to the fixed contact 39. A stationary arc traveling plate 71 extending from the tip of the child 39, and a movable arc traveling plate 52 disposed facing the stationary arc traveling plate 71 and electrically connected to the movable contact 33. , _A grid device 72 that holds a plurality of arc-extinguishing magnetic plates 74 interposed between the movable-side and fixed-side arc traveling plates 52 and 71 with an insulating side plate 73 at intervals δ _A , and a body 10a made of an insulating material. Smell of circuit breaker stored in 10b Insulation side plate 7 of grid device 72
3 is arranged with respect to the stationary side arc traveling plate 71 with a space δ _B opened.

Here, between the insulating side plate 73 and the fixed side arc traveling plate 71 of the grid device 72, the body 10a,
It is preferable to interpose a protrusion 100 made of an insulating material and protruding from 10b. In addition, the space δ between the fixed-side arc traveling plate 71 and the arc-extinguishing magnetic plate 74 adjacent to the arc-extinguishing plate 71 due to the respective intervals δ _A between the arc-extinguishing magnetic plates 74 of the grid device 72.
_It is preferable to make _B wider.

[0034]

According to the present invention, however, the grid device 72
Since the space δ _B is provided between the insulating side plate 73 and the fixed side arc traveling plate 71, when the arc occurs due to the overcurrent, the arc travels from the contact portion 30 and the grid device 72
It is divided and extinguished at. At this time, the arc gas is generated by the insulating side plate 73 of the grid device 72 and the fixed side arc traveling plate 71.
Since it is easy to be discharged through the space δ _B between and, the gas retention around the corner of the insulating side plate 73 is reduced, and the heat of the arc is also easily discharged through the space δ _B ,
It is possible to prevent the melt from adhering between the insulating side plate 73 and the fixed side arc traveling plate 71. Therefore, since the insulation distance can be maintained by the space δ _B , the insulation state can be surely and stably ensured.

[0035]

Embodiments of the present invention will be described below with reference to the drawings. The basic configuration and operation of the circuit breaker of this embodiment are as described in the related art, and detailed description will be omitted.
The body 10 of the circuit breaker is made of an insulating material such as synthetic resin, and is opened and closed by operating the handle 41 as shown in FIG. The movable contactor 33 that is pole-driven and the movable contactor 3
Fixed contactor 3 having a fixed contact 31 which comes into contact with and separates from a contact portion 30 provided at the tip of the movable contactor 33 facing the contactor 3.
9 and a fixed-side arc traveling plate 71 that is electrically connected to the fixed contact 39 and extends from the tip of the fixed contact 39.
A movable arc traveling plate (yoke) 52 which is disposed so as to face the fixed arc traveling plate 71 and is electrically connected to the movable contact 33, and movable and fixed arc traveling plates 52 and 71. _A grid device 72 in which a plurality of arc-extinguishing magnetic plates 74 interposed therebetween are held by insulating side plates 73 at intervals δ _A
And are stored respectively.

As shown in FIG. 1, the grid device 72 includes a plurality of arc-extinguishing magnetic plates 74 made of a conductive plate inside a substantially U-shaped insulating side plate 73 made of an insulating material.
The arc extinguishing magnetic plates 74 are arranged so as to be substantially parallel to the movable arc traveling plate 52 and the fixed arc traveling plate 71, respectively. In addition, the grid device 72
The insulating side plate 73 is provided with a space δ _B with respect to the fixed side arc traveling plate 71. This space δ _B facilitates discharge of the arc gas and reduces gas retention around the corners of the insulating side plate 73 to ensure an insulating state between the insulating side plate 73 and the fixed side arc traveling plate 71. It is for doing. Further, projections 100 made of an insulating material are projected from the bodies 10a and 10b, and the grid device 72
It is inserted between the insulating side plate 73 and the fixed side arc traveling plate 71, and the gap between the protrusion 100 and the insulating side plate 73 and the step of the protrusion 100 can ensure a larger insulation distance. And fixed side arc traveling plate 7
1 and the space δ between the arc-extinguishing magnetic plate 74 close to it
_B is a space δ _B that is the most effective for ensuring insulation, and this space δ _B is set to be wider than the intervals δ _A (<δ _B ) between the plurality of arc-extinguishing magnetic plates 74 of the grid device 72. .

When the movable contact 32 (FIG. 2) is separated from the fixed contact 31 and an arc is generated, the magnetic field generated around by the current flowing through the terminal plate 21a and the movable contact 33 and the current flowing through the arc. Due to the generated electromagnetic force, the arc moves downward in FIG. 2, and one end of the arc travels on the arc traveling plate 71 so as to approach the grid device 72, is extended, and is divided and extinguished.

At this time, the insulating side plate 7 of the grid device 72
3 is disposed with respect to the stationary side arc traveling plate 71 with a space δ _B opened, and in this space δ _B , a protrusion 100 made of an insulating material.
Because of the interposition, the gap between the insulating side plate 73 and the protrusion 100 and the stepped portion of the protrusion 100 can secure a larger insulation distance, and thus the insulation can be secured easily. That is, when the arc generated by the overcurrent is divided and extinguished by the grid device 72, a suction force is generated between the movable side arc traveling plate 52 and the fixed side arc traveling plate 71, and the fixed side arc traveling plate 71 is Although it tends to bend toward the grid device 72 side, this can be blocked by the protrusion 100.
Moreover, the gas generated by the arc is discharged from the contact portion 30 to the outside of the vessels 10a and 10b through the exhaust portion. At this time, the gas escapes from the surface of the protrusion 100, but there is no portion that serves as a gas retention portion. In addition, soot and the like are unlikely to adhere to the surface of the protrusion 100. Further, the melt generated by the heat of the arc is scattered to the grid device 72 side, but a large space δ _B between the arc-extinguishing magnetic plate 74 and the fixed-side arc traveling plate 71 which are close to the fixed-side arc traveling plate 71 is taken. Therefore, clogging of the melt into the space [delta] _B is not generated. Therefore, since the gas generated by the arc is easily discharged through the space δ _B between the insulating side plate 73 of the grid device 72 and the fixed side arc traveling plate 71, the gas retention around the corners of the insulating side plate 73 is reduced, Further, since the heat of the arc is also easily discharged through the space δ _B , it is possible to prevent the melt from adhering between the insulating side plate 73 and the fixed side arc traveling plate 71, and as a result, the insulating distance is maintained by the space δ _B. As a result, reliable and stable insulation can be secured. As a result, the insulation after the extinction of the arc is maintained by the space δ _B between the arc-extinguishing magnetic plate 74 and the fixed-side arc traveling plate 71 which are close to the fixed-side arc traveling plate 71.
And the surface of the protrusion 100 made of an insulating material. Furthermore, the movable arc traveling plate 52 and the stationary arc traveling plate 52 are provided by making the intervals δ _A between the plurality of arc extinguishing magnetic plates 74 of the grid device 72 narrower than the space δ _B and providing a difference therebetween. There is no need to increase during 71. That is, the plurality of arc extinguishing magnetic plates 74 of the grid device 72
If each space δ _A between them is widened similarly to the space δ _B between the fixed side arc traveling plate 71 and the arc extinguishing magnetic plate 74 adjacent thereto, the fixed side arc traveling plate 71 and the movable side arc traveling plate 52.
And the grid device 72 becomes larger. In order to prevent this, it is necessary to secure a large space δ _B that is most effective for ensuring insulation. Therefore, the respective intervals δ between the plurality of arc extinguishing magnetic plates 74 of the grid device 72
_A and by narrower than the space [delta] _B between the fixed-side arc running plate 71 and the extinguishing magnetic plates 74 adjacent thereto, can be increased the most effective space [delta] _B to ensure insulation.

The movable side arc traveling plate (yoke) 52
Is arranged close to the insulating side plate 73 of the grid device 72, but since arc intrusion is faster on the fixed side arc traveling plate 71 side than on the movable side arc traveling plate 52 side, the arc is cut off by the grid device 72. When arcing, a phenomenon in which a molten material is generated due to heat generated by the arc and adheres between the arc-extinguishing magnetic plates 74 of the grid device 72, or soot or the like adheres around the corners of the insulating side plate 73 Fixed side arc traveling plate 71
Of the stationary side arc traveling plate 71. Therefore, by securing the insulation on the side of the stationary side arc traveling plate 71, such a phenomenon can be effectively prevented, and the stationary side arc traveling plate 71 and the movable side arc traveling plate 52 are It is possible to prevent an increase in the distance and prevent the grid device 72 from increasing in size.

[0040]

As described above, according to the first aspect of the present invention, the insulating side plate of the grid device is arranged with a space from the fixed side arc traveling plate. Therefore, when an arc is generated by an overcurrent, the arc gas is generated. Tends to be discharged through the space between the insulating side plate of the grid device and the fixed side arc traveling plate, so that gas retention around the corners of the insulating side plate is reduced, and the heat of the arc is also easily discharged through the space. Therefore, as a result of preventing the melt from adhering between the insulating side plate and the fixed side arc traveling plate, the insulation distance can be maintained by the space, so that reliable and stable insulation can be ensured.

Further, according to the invention of claim 2, since the projection of the insulating material protruding from the body is interposed between the insulating side plate and the fixed side arc traveling plate of the grid device of claim 1,
In addition to the effect of the first aspect, the insulation distance can be further increased by the gap between the insulating side plate and the protrusion and the step of the protrusion, and therefore the insulation can be easily ensured. Claim 3
According to the invention of claim 1, the space distance between the stationary arc traveling plate and the arc-extinguishing magnetic plate adjacent thereto is made wider than the intervals between the arc-extinguishing magnetic plates of the grid device according to claim 1. In addition to the effect described in Item 1, clogging of the melt between the fixed-side arc traveling plate side where the arc enters quickly and the arc-extinguishing magnetic plate adjacent thereto can be reduced, and more reliable and stable insulation can be secured. Become. In addition, each space between the plurality of arc-extinguishing magnetic plates of the grid device is made narrower than the space between the fixed-side arc traveling plate and the arc-extinguishing magnetic plate adjacent thereto, thereby preventing the grid device from becoming large. However, the most effective space for ensuring insulation can be secured.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a grid device according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of the circuit breaker with the same cover removed.

FIG. 3 is an exploded perspective view of the above circuit breaker.

FIG. 4 is an external perspective view of the above circuit breaker.

FIG. 5 is a cross-sectional view of the circuit breaker in the same closed state.

FIG. 6 is a cross-sectional view of the circuit breaker of the above in an open state.

FIG. 7 is a sectional view of the same trip state.

FIG. 8 is a cross-sectional view of a main part of a conventional grid device.

[Explanation of symbols]

10a, 10b Body 30 Contact part 33 Movable contact 39 Fixed contact 52 Movable side arc traveling plate 71 Fixed side arc traveling plate 72 Grid device 74 Arc extinguishing magnetic plate 100 Protrusion δ _A space δ _B space

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoichi Yokoyama 1048 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Works Co., Ltd.

Claims (3)

[Claims] 1. A movable contactor that is opened and closed by a handle operation and is forcibly driven to open in response to an abnormal current, and a contact portion that is provided at the tip of the movable contact member facing the movable contactor. A fixed contact with a fixed contact that comes in contact with and separated from it, a fixed side arc running plate electrically connected to the fixed contact and extending from the tip of the fixed contact, and facing the fixed side arc running plate. A movable arc traveling plate electrically connected to the movable contact and a plurality of arc extinguishing magnetic plates interposed between the movable side stationary arc traveling plate and the stationary arc traveling plate separated by insulating side plates. A circuit breaker in which the held grid device is housed in a body made of an insulating material, wherein the insulating side plate of the grid device is arranged with a space between the fixed side arc traveling plate and the circuit breaker. 2. The circuit breaker according to claim 1, wherein a projection made of an insulating material is provided between the insulating side plate and the fixed side arc traveling plate of the grid device so as to project from the body. 3. The space between the arc-extinguishing magnetic plate and the arc-extinguishing magnetic plate adjacent to the fixed-side arc traveling plate is made wider than the intervals between the arc-extinguishing magnetic plates of the grid device.
The described circuit breaker.