JP5595225B2 - Circuit breaker - Google Patents

Description

  The present invention relates to a circuit breaker that includes a magnetic movable iron core and a magnetic fixed iron core having a magnetic pole facing the attracted portion of the movable iron core, and that automatically shuts off when the movable iron core is attracted to the fixed iron core. Is.

  8 is a perspective view showing a main part of a conventional circuit breaker tripping device, and FIG. 9 is a side view of FIG. In the figure, 1 is a fixed iron core, formed in a flat plate shape with a magnetic material such as an iron plate, 2 is a mag support, formed by bending a non-magnetic material such as a stainless steel plate into a U shape, The pair of sides bent in a shape has a pair of stoppers 2a at the lower end, a pair of spring hooking pieces 2b at the upper end, and a pair of U-shaped grooves 2c at the substantially central portion. Reference numeral 3 denotes a heater. The lower end portion is L-shaped, and a female screw 3a that is fastened to a shunt terminal (not shown) is connected to the upper end portion, and a connection conductor 5 connected to the load side terminal 4 is connected. Reference numeral 6 denotes a flat bimetal, that is, a thermal element, which is fixed integrally with a rivet 7 with a heater 3 and a mag support 2 sandwiched between the fixed core 1. Reference numeral 8 denotes an adjusting screw attached to the free end of the bimetal 6 and adjusts thermal operation characteristics. 9 is a lock nut.

  Reference numeral 10 denotes a movable iron core, which is formed by bending a U-shape with a magnetic material such as an iron plate, and has a pair of movable pieces 10a facing the fixed core 1 and bearings on a pair of sides bent in a U-shape. Part 10b, one side bent in a U-shape extends upward, and at its tip, an operating piece 10c for pressing a trip bar (not shown) of the opening / closing mechanism, and a U-shaped The bottom surface has a protrusion 10d that is pressed against the stopper 2a of the mug support 2. Reference numeral 11 denotes a double torsion type return spring, which is pivotally supported by a shaft 12 at a substantially central portion of the movable iron core 10 and a double torsion foot 11a is hooked on the spring hook piece 2b. Further, the shaft 12 is inserted into the pair of U-shaped grooves 2c of the mag support 2 to assemble the tripping device.

In such a circuit breaker tripping device, when a current flows through the connecting conductor 5 and the heater 3 connected to the shunt terminal, a magnetic flux passing through the fixed iron core 1 and the movable iron core 10 is generated. The movable iron core 10 is instantaneously attracted to the fixed iron core 1 against the spring force of the return spring 11 by the attraction force generated by the magnetic flux during the electromagnetic trip. By the operation of the movable iron core 10, the trip bar of the opening / closing mechanism is rotated to perform automatic shut-off. Further, the trip bar of the opening / closing mechanism portion is rotated by the bending operation of the bimetal 8 at the time of tripping due to thermal motion, and thereafter it is automatically shut off by the same operation as described above.

JP-A-8-96689 (FIGS. 1 to 3 and explanation thereof)

  In the circuit breaker tripping device as described above, when configuring a low-instrument tripping device in which the instantaneous tripping current value is set to a low value, the auxiliary that is bent into a U-shape inside the movable core 10 An iron core (magnetic material) is added (not shown), and the fixed iron core 1 is further thickened and changed to a product (magnetic material) (not shown). With the above configuration, the attractive force of the fixed core 1 and the movable piece is increased by increasing the magnetic facing area between the movable piece and the fixed core 1 that are arranged opposite to each other. Since the increase is accompanied, there is a problem that the trip device becomes large. In addition to the addition of an auxiliary iron core to the standard model, it is also necessary to change the fixed iron core, resulting in an increase in assembly time and part types.

  The present invention has been made in view of the above-described circumstances, and it is possible to shorten the initial magnetic gap between the magnetic pole of the fixed iron core and the movable iron core without reducing the tripping stroke of the movable iron core. The purpose is to ensure a high suction force of the movable iron core.

A circuit breaker according to the present invention includes a magnetic movable iron core and a magnetic fixed iron core having a magnetic pole facing the attracted portion of the movable iron core, and is automatically cut off by an operation in which the movable iron core is attracted to the fixed iron core. In the circuit breaker, a magnetic auxiliary iron core is provided on the magnetic pole side of the fixed iron core in the movable iron core so as to oppose the magnetic pole of the fixed iron core and constitutes a movable iron core portion with the movable iron core, and the magnetic pole automatic and the magnetic attraction force generated between each other of the suction portion of the movable core, by the magnetic attraction force generated between each other of the magnetic pole and the auxiliary core, by operation of the movable iron core is attracted to the fixed iron core A circuit breaker for breaking ,
The length B in the opposite direction of the initial gap between the auxiliary iron core and the magnetic pole of the fixed iron core is equal to the length of the initial gap between the movable iron core and the magnetic pole of the fixed iron core. An auxiliary iron core that is shorter than the length A in the opposite direction and reduces the initial gap between the movable iron core portion and the fixed iron core without reducing the tripping stroke of the movable iron core portion;
The movable core portion is pivotally attached to the fixed iron core at an intermediate portion thereof, and has an operation piece portion for performing a circuit breaker trip at one of both ends spaced from the pivoted portion. In a non-attraction operation state in which the attracted portion is not attracted magnetically to the magnetic pole, the opposing gap length between the attracted portion and the magnetic pole end surface on the attracted portion side of the magnetic pole is , Long enough to move away from the pivoted part,
In a non-attraction operation state where the attracted part is not attracted to the magnetic pole, the facing gap length between the auxiliary iron core and the magnetic pole is substantially constant within the entire range where the auxiliary iron core and the magnetic pole are opposed to each other. And
The circuit breaker according to claim 1 , wherein the auxiliary iron core is not in contact with the fixed iron core in a state where the attracted portion is magnetically attracted to the magnetic pole .

The present invention relates to a circuit breaker including a magnetic movable iron core and a magnetic fixed iron core having a magnetic pole facing the attracted portion of the movable iron core, and automatically shutting off by an operation in which the movable iron core is attracted to the fixed iron core. A magnetic auxiliary iron core is provided on the magnetic pole side of the fixed iron core in the movable iron core so as to be opposed to the magnetic pole of the fixed iron core and constitutes a movable iron core portion with the movable iron core. A circuit breaker that automatically shuts off the movable core portion by the action of being attracted to the fixed core by the magnetic attraction force generated between the attracted portions and the magnetic attraction force generated between the magnetic pole and the auxiliary iron core . a is, the auxiliary iron core, the magnetic pole of the auxiliary core and the opposite direction of the length B of the initial gap between the magnetic poles of said stationary iron core, the movable iron core and the fixed iron core The initial gap is shorter than the length A in the opposite direction, and the auxiliary core shortens the initial gap between the movable core and the fixed core without reducing the tripping stroke of the movable core. The movable iron core portion is pivotally attached to the fixed iron core at an intermediate portion thereof, and has an operation piece portion for performing a circuit breaker trip at one of both ends spaced from the pivoted portion, In a non-attraction operation state in which the attracted portion is not attracted magnetically to the magnetic pole, a gap length between the attracted portion and the pole end surface on the attracted portion side of the magnetic pole However, the auxiliary iron core is within the entire range where the auxiliary iron core and the magnetic pole face each other in a non-attraction operation state in which the attracted portion is not attracted to the magnetic pole, as the distance from the pivotally attached portion increases. And the magnetic pole pair A gap length is substantially constant, in a state where the object to be sucked portion to said pole is magnetically attracted is the circuit breaker, characterized in that the auxiliary core is not in contact with the fixed iron core Therefore, the tripping stroke of the movable core is not reduced, the initial magnetic gap between the magnetic pole of the fixed core and the movable core can be shortened, and a high attractive force of the movable core to the fixed core can be ensured.

It is a figure which shows Embodiment 1 of this invention, and is a perspective view which shows an example of the principal part of the tripping device of a circuit breaker. It is a figure which shows Embodiment 1 of this invention, and is a side view which shows an example of the principal part of the tripping device of a circuit breaker. It is a figure which shows Embodiment 1 of this invention, and is the top view of the partial cross section seen in the direction of the arrow from the III-III line in FIG. It is a figure which shows Embodiment 1 of this invention, and is a side view which shows an example of the internal structure of the circuit breaker incorporating the tripping device illustrated in FIGS. It is a figure which shows Embodiment 2 of this invention, and is a perspective view which shows the other example of the principal part of the tripping device of a circuit breaker. It is a figure which shows Embodiment 2 of this invention, and is a side view which shows the other example of the principal part of the tripping device of a circuit breaker. It is a figure which shows Embodiment 2 of this invention, and is a top view of the partial cross section seen in the direction of the arrow from the VII-VII line in FIG. It is a perspective view which shows the principal part of the trip device of the conventional circuit breaker. It is a side view which shows the principal part of the trip device of the conventional circuit breaker.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to FIGS. 1 is a perspective view showing an example of a main part of a circuit breaker tripping device, FIG. 2 is a side view showing an example of a main part of a circuit breaker tripping device, and FIG. 3 is a line III-III in FIG. FIG. 4 is a side view showing an example of the internal structure of a circuit breaker incorporating the tripping device exemplified in FIGS. 1 to 4.

  1 to 4, the circuit breaker 20 includes a base 21, a cover 22, a power supply side terminal 23, a tripping device 24, a mover holder 25, a mounting screw 26, an opening / closing mechanism 27, and a load side terminal 28. ing.

  Both the base 21 and the cover 22 are formed of a synthetic resin material. The mounting screw 26 connects the tripping device 24 and the mover holder 25. The opening / closing mechanism 27 includes a known trip bar 27a.

Trip device 24 includes a fixed iron core 31, the heater conductor 32, thermal circuit element 33 of the bimetal such as rivets 34, adjustment screws 35, locking nuts 36, the movable iron core 37, an auxiliary core 41, the return spring 38, and the shaft 39 It has.

  The fixed iron core 31 is formed by bending a single magnetic material such as an iron plate into a substantially U shape, and includes a spring latch piece 31a, a pair of legs 31b, a bridge 31c, a pair of side walls 31d, A pair of contact surfaces (magnetic pole end surfaces) 31e and a stopper 31g are integrally provided.

  The movable iron core 37 is integrally formed with a sucked portion 37a, a pair of bearing portions 37b, and an operation piece portion 37c, which are called movable pieces, by a single magnetic material such as an iron plate.

  In the movable iron core 37, the bearing portion 37 b formed on each of a pair of side portions bent in a U-shape is extended in the middle portion upward from the center portion, and the trip bar of the opening / closing mechanism portion 27. The operation piece 37c that presses 27a is formed at the lower portion, and the suctioned portion 37a that faces the pair of magnetic poles of the fixed iron core 31 is formed respectively.

  The return spring 38 is a torsion coil spring of a double torsion type, has a coil portion 38a and a pair of legs 38b and 38c that are closely wound, engages between the movable iron core 37 and the fixed iron core 31, and is always movable. The iron core 37 is urged in the direction of separating from the fixed iron core 31.

  The auxiliary iron core 41 is formed by bending a single magnetic material such as an iron plate into a U shape, and is coupled to the surface of the movable iron core 37 on the fixed iron core side by a coupling means such as spot welding. The upper end of the auxiliary iron core 41 is provided with a rectangular notch 41a that is formed in a rectangular shape so that the return spring 38 is engaged with the movable iron core 37. The coil of the return spring 38 is provided in the rectangular notch 41a. A part of the portion 38a is disposed.

  The shaft 39 is a nonmagnetic shaft such as stainless steel.

  The heater conductor 32 is formed by bending a conductor, and has an L-shaped female screw 32a fastened with a mover holder 25 and a mounting screw 26 at a lower end portion thereof, and a heater portion 32b at a central portion thereof.

  The thermal element 33 made of a flat bimetal or the like is disposed so that the heater portion 32 b of the heater conductor 32 is sandwiched between the lower end portion thereof and the bridging portion 31 c of the fixed iron core 31. The lower end portion of the thermal element 33, the bridging portion 31c of the fixed iron core 31, and the heater portion 32b of the heater conductor 32 are integrally fixed by a rivet 34.

The lower end portion of the thermal element 33 is in surface contact with the heater portion 32b of the heater conductor 32, and the heater portion 3
Heated by 2b. An adjusting screw 35 attached by a lock nut 36 is provided at the free end of the thermal element 33, and the thermal operating characteristic for the cutoff operation by the thermal element 33 is adjusted by the adjustment screw 35 as is well known. The

  The surface opposite to the thermal element 33 of the heater portion 32 b of the heater conductor 32 and both end surfaces connected to the surface are surrounded by the bridging portion 31 c of the fixed iron core 31 and both side walls 31 d of the fixed iron core 31. The main magnetic circuit of the magnetic flux generated by the load current flowing through the heater portion 32 b includes the bridging portion 31 c of the fixed iron core 31, both side walls 31 d of the fixed iron core 31, and the attracted portion 37 a of the movable iron core 37. And passes through the auxiliary iron core 41.

  When the shortest initial gap length between the auxiliary iron core 41 and the fixed iron core in the state not attracted by the magnetic pole of the fixed iron core 31 is B1, the fixation in the state of not being attracted by the magnetic pole of the fixed iron core 31 When the shortest initial gap length between the iron core 31 and the movable iron core 37 is A, the magnitude relationship between the initial gap A and the initial gap B1 is B1 <A.

  In the circuit breaker configured in this way, when an overload current flows through the path of the power source side terminal 23 → mover holder 25 → female screw 32a → heater part 32b → load side terminal 28, the bimetal 33 is generated by the heat generated by the heater part 32b. Is heated and curved. By this bending, the trip bar 27a is pushed by the adjusting screw 35 attached to the bimetal 33, and the opening / closing mechanism 27 operates to trip the circuit breaker.

  When a large current such as a short-circuit current flows through the heater portion 32b, the fixed iron core 31 is strongly magnetized by the magnetic flux generated by the large current, and the suctioned portion 37a of the auxiliary iron core 41 and the movable iron core 37 is instantaneously attached to the fixed iron core 31. The movable iron core 37 rotates about the shaft 39 against the spring force of the return spring 38, and the operating piece 37 c rotates about the shaft 39 as the movable iron core 37 rotates. To do. By the rotation of the operation piece portion 37c, the operation piece portion 37c pushes the trip bar 29a and trips the circuit breaker in the same manner as described above to perform a breaking operation.

  In the circuit breaker configured as in the first embodiment described above, the auxiliary iron core 41 having a simple shape is added to the tripping device, so that the fixed iron core is not changed without changing the tripping stroke of the movable iron core 37. The initial gap between the movable iron core 31 and the movable iron core can be shortened, and in addition to the magnetic force with the movable iron core 37 of the fixed iron core 31, the magnetic force between the auxiliary iron core 41 and the fixed iron core 31 can be generated. An improvement in the suction force of the movable iron core 51 to the iron core 31 can be realized.

  Further, since the suction force is proportional to the opposed area and inversely proportional to the square of the gap, in other words, even if the opposed area of the fixed iron core 31 and the movable iron core 37 is not increased, in other words, the outer dimensions of the fixed iron core 31 and the movable iron core 37. Even if the number is not increased, the attractive force can be improved in a square proportional manner by shortening the initial gap between the fixed core 31 and the movable core 51.

As described above, the first embodiment includes the magnetic movable iron core 37 and the magnetic fixed iron core 31 having a magnetic pole facing the attracted portion 37a of the movable iron core 37, and the movable iron core 37 is rotated. provided on the supporting structure is the fixed iron core for rotatably supporting the auxiliary core 41 and the movable iron core 37 by magnetic attraction force generated between the magnetic poles and mutual of the suction portion 37a of the movable core of the fixed iron core 31 is the A circuit breaker that automatically shuts off by the action of being attracted by the fixed iron core 31 and that has a structure in which the auxiliary iron core 41 is rolled into the inside of the fixed iron core 31 during operation is illustrated.

Further, as described above, the first embodiment is attracted to the initial gap A between the attracted portion 37a of the movable core 37 and the magnetic pole of the fixed core 31, the auxiliary core 41, and the fixed core. A low-instrument type circuit breaker in which the magnitude relationship between the auxiliary iron core 41 and the initial gap B1 between the auxiliary iron core 41 and the fixed iron core 31 in the absence is B1 <A is illustrated.

  Further, as described above, in the first embodiment, the heater conductor 32, the fixed iron core 31 that is integrally attached to the heater conductor 32 and has a spring retaining piece 31a and a pair of magnetic poles at the upper end, and the fixed The suctioned portion 37a facing the magnetic pole of the iron core 31, a pair of bearing portions 37b in the central portion, and an operation piece 27c for pressing the trip bar 27a at the upper end portion are rotated based on the short-circuit current flowing through the heater conductor 32. In the circuit breaker having the movable iron core 37 and the return spring 38 in the bearing portion 37b of the movable iron core 37, the magnetic gap between the fixed iron core 31 and the movable iron core portion 51 can be shortened without reducing the tripping stroke even during operation. A possible low instrument circuit breaker is illustrated.

  In the first embodiment, when the specification of the low-instrument circuit breaker is changed from the standard model, the number of parts changed due to the manufacturing assembly process is small (two points in the past and one point in the present invention), and has high suction characteristics. It can be realized.

Embodiment 2. FIG.
A second embodiment of the present invention will be described below with reference to FIGS. FIG. 6 is a perspective view showing another example of the main part of the tripping device for the circuit breaker, and FIG. 7 is a plan view of a partial cross section seen from the line VII-VII in FIG.

  In the second embodiment, as illustrated in FIGS. 6 and 7, a magnetic movable iron core 37 and a magnetic fixed iron core 31 having a magnetic pole facing the attracted portion 37a of the movable iron core 37 are provided. A support structure that rotatably supports the movable iron core 37 is provided across the fixed iron core 31 and the movable iron core 37, and is movable by a magnetic attractive force generated between the fixed iron core 31 and the movable iron core portion 51. A low-instrument circuit breaker in which the iron core 51 (an assembly of the movable iron core 37 and the auxiliary iron core 41) is automatically cut off by the operation of being attracted to the fixed iron core 31, and is generated from the magnetic pole of the fixed iron core 31. The magnetic increase structure that increases the magnetic force is a circuit breaker provided in the movable core portion 51.

  In the second embodiment, a low-instrument type circuit breaker is illustrated in which the auxiliary iron core 42 is shaped along the contact surface (magnetic pole end face) 31e of the fixed iron core 31.

When the initial gap between the auxiliary iron core 42 and the fixed iron core when not attracted to the magnetic poles of the fixed iron core 31 is B2, the magnitude relationship between the initial gap A between the movable iron core 37 and the fixed iron core 31 is , B2 <A.

  In the second embodiment, as is well known, the auxiliary iron core 42 has a shape along the contact surface (magnetic pole end face) 31e of the fixed iron core 31, and therefore, an initial gap C between the fixed iron core 31 and the auxiliary iron core 42. Is made even up to the bottom surface side of the auxiliary iron core, the suction force at the beginning of pulling can be efficiently produced, and the suction torque is increased.

  Since structures and functions other than those described above in the second embodiment are the same as those in the first embodiment, the description thereof is omitted.

Further, the first embodiment and the embodiment of the present invention described above have the following specific features, if further described.
[Feature 1]
A circuit including a magnetic movable iron core 37 and a magnetic fixed iron core 31 having a magnetic pole 31 f facing the attracted portion 37 a of the movable iron core 37, and automatically shutting off when the movable iron core 37 is attracted to the fixed iron core 31. In the circuit breaker,
A magnetic auxiliary iron core 41 is provided on the movable iron core 37 on the side of the magnetic pole 31f of the fixed iron core 31 so as to face the magnetic pole 31f of the fixed iron core 31 and constitutes the movable iron core portion 51 with the movable iron core 37.
A magnetic attraction force generated between each other of the magnetic poles 31f and the suction portion 37a of the movable iron core 37, by the magnetic attraction force generated between each other of the magnetic pole 31 f and the auxiliary core 41, the movable iron core 51 the A circuit breaker that automatically shuts off by an action sucked by the fixed iron core 31.
[Feature 2]
In the circuit breaker according to Feature 1,
The movable iron core 37 and the auxiliary iron core 41 are integrated (see FIGS. 2, 3, 6, and 7).
A circuit breaker characterized by that.
[Feature 3]
In the circuit breaker according to Feature 2,
The circuit breaker, wherein the movable iron core 37 and the auxiliary iron core 41 are separate bodies, and the separate movable iron core 37 and the auxiliary iron core 41 are integrated by a coupling means.
[Feature 4]
In the circuit breaker according to any one of features 1 to 3,
The circuit breaker characterized in that the tripping stroke of the movable core 37 before the auxiliary iron core 41 is provided and the tripping stroke of the movable iron core 37 after the auxiliary iron core 41 is provided are the same.
The tripping stroke of the movable core 37 is a moving distance of the operation piece portion 37 c until the movable core 37 is attracted to the fixed core 31.
[Feature 5]
In the circuit breaker according to any one of features 1 to 4,
The initial gap between the movable core 51 and the fixed core 31 is provided before the auxiliary core is provided (the initial gap between the movable core 37 and the fixed core 31). A circuit breaker characterized by having a shorter distance after the start (the initial gap between the auxiliary iron core 41 and the fixed iron core 31).
The “initial gap” means “the magnetic attraction between the movable core 51 and the fixed core 31 in a state where the movable core 51 is not magnetically attracted to the fixed core 31. This is the shortest interval (gap) among the contributing intervals (gap).
[Feature 6]
In the circuit breaker according to any one of features 1 to 5,
The fixed iron core 31 includes a pair of side wall portions 31d and 31d facing each other at a predetermined distance, and a bridge portion 31c that bridges one end of each of the pair of side wall portions 31d and 31d.
A heater conductor 32 through which a load current flows is surrounded by the pair of side wall portions 31d and 31d and the bridging portion 31c and disposed near the bridging portion 31c.
The other opposite ends of the pair of side wall portions 31d and 31d are the magnetic poles 31f and 31f (see FIGS. 2, 3, 6, and 7).
A circuit breaker characterized by that.
[Feature 7]
In the circuit breaker according to Feature 6,
The movable iron core 37 is opposed to the magnetic pole end surface 31e opposite to the bridging portion 31c of the magnetic poles 31f and 31f at the other end facing each other (see FIG. 2).
The circuit breaker, wherein the auxiliary iron core 41 is opposed to the mutually opposing side surfaces 31fe of the magnetic poles 31f, 31f facing each other (see FIG. 3).
[Feature 8]
In the circuit breaker according to Feature 6,
The length B in the opposing direction of the initial gap between the auxiliary iron core 41 and the magnetic pole 31f of the fixed iron core 31 is the initial gap between the movable iron core 37 and the magnetic pole 31f of the fixed iron core 31. Shorter than the length A in the facing direction (see FIGS. 3 and 7)
A circuit breaker characterized by that.
[Feature 9]
In the circuit breaker according to Feature 6,
The surface of the magnetic poles 31f, 31f facing each other virtually extending the pole end surface 31e opposite to the bridging portion 31c, and the surface 41e of the auxiliary iron core 41 on the bridging portion 31c side virtually extending. Is not the same plane or parallel (see Figs. 2 and 3)
A circuit breaker characterized by that.
[Feature 10]
The circuit breaker according to claim 6,
A surface obtained by virtually extending the magnetic pole end surface 31e opposite to the bridging portion 31c of the magnetic poles 31f and 31f facing each other and a surface 41e on the bridging portion side 31c of the auxiliary iron core 41 are virtually extended. The surface is the same or parallel (see FIGS. 6 and 7)
A circuit breaker characterized by that.
[Feature 11]
In the circuit breaker according to any one of features 1 to 10,
The movable core portion 51 is pivotally attached to the fixed iron core 31 by a shaft 39 at an intermediate portion thereof, and has an operation piece portion 37c that performs a circuit breaker trip at one of both ends spaced from the pivoted portion. The suctioned portion 37a is provided on the other end of both ends (see FIGS. 1, 2, 5, and 6).
In a non-attraction operation state where the attracted portion 37a is not magnetically attracted to the magnetic pole 31f, the opposing gap length between the magnetic pole end surface 31e on the attracted portion 37a side of the magnetic pole 31f and the attracted portion 37a is , Long enough to move away from the pivoted part,
In a non-attraction operation state in which the attracted portion 37a is not magnetically attracted to the magnetic pole 31f, the auxiliary iron core 41 and the magnetic pole 31f are within the entire range where the auxiliary iron core 41 and the magnetic pole 31f face each other. Is substantially constant (see FIGS. 2, 3, 6, and 7).
A circuit breaker characterized by that.
[Feature 12]
In the circuit breaker according to any one of features 1 to 11,
In a state where the attracted portion 37a is magnetically attracted to the magnetic pole 31f, the auxiliary iron core 41 is not in contact with the fixed iron core 31 (see FIGS. 2, 3, 6, and 7).
A circuit breaker characterized by that.
[Feature 13]
In the circuit breaker according to any one of features 6 to 12,
The auxiliary iron core 41 is disposed between the pair of side wall portions 31d and 31d,
A width 41W in the opposing direction of the pair of side wall portions 31d and 31d of the auxiliary iron core 41 is narrower than a width 37W in the opposing direction of the pair of side wall portions 31d and 31d of the suctioned portion 37a (see FIGS. 3 and 7). reference)
A circuit breaker characterized by that.
[Feature 14]
A magnetic fixed iron core 31 having a magnetic movable core portion 37 and a magnetic pole 31 f facing the attracted portion 37a of the movable iron core portion 51 is provided, and magnetic attraction generated between the magnetic pole 31f and the attracted portion 37a. The circuit breaker automatically shuts off when the movable core portion 51 is attracted to the fixed core 31 by force, and the movable core portion 51 and the fixed core 31 can be disconnected without reducing the tripping stroke of the movable core portion 51. A low-instrument circuit breaker characterized by using an auxiliary iron core 41 that reduces the initial gap.
[Feature 15]
The circuit breaker according to Feature 14,
The movable iron core 37 and the auxiliary iron core 41 joined to the movable iron core 37 are pivotally attached, and the auxiliary iron core 41 is recessed inside the fixed iron core 31 before a suction operation. A low-instrument type circuit breaker.
[Feature 16]
The circuit breaker according to Feature 15,
And initial gap A between the magnetic poles of the fixed iron core 31 and the suction portion 37e of the movable core 37, the magnitude relation between the initial gap B between the magnetic poles 31 f of the fixed iron core 31 and the auxiliary core 41, B <A low-circuit type circuit breaker characterized by being A.
[Feature 17]
The circuit breaker according to any one of features 14 to 16,
The shape of the auxiliary iron core 41 is in contact with the magnetic pole end surface 31e of the fixed iron core 31, and the initial gap between the fixed iron core 31 and the auxiliary iron core 41 is made even to the bottom surface side of the auxiliary iron core 41. A low-instrument type circuit breaker in which an attractive force is exerted even on the bottom surface side of the movable iron core 51 away from the moving shaft (shaft or the like)
[Feature 18]
The circuit breaker according to any one of features 14 to 16,
The auxiliary iron core 41 has a shape that keeps a certain gap on the magnetic pole end surface 31e of the fixed iron core 31, and has an initial gap between the fixed iron core 31 and the auxiliary iron core 41 evenly to the bottom surface side of the auxiliary iron core 41. Therefore, the low-instrument circuit breaker is characterized in that an attractive force also acts on the bottom surface side of the movable iron core portion away from the movable iron core rotating shaft 39.
[Feature 19]
Achieves improved suction force without increasing the outer dimensions of the movable core and fixed core, and when changing the specifications of the low-instrument circuit breaker from the standard model, an inexpensive low-instrument circuit breaker with only one change point Can be provided.
[Feature 20]
A magnetic movable iron core and a magnetic fixed iron core having a magnetic pole facing the attracted portion of the movable iron core are provided, and the movable iron core is attracted to the fixed iron core by a magnetic attraction force generated between the magnetic pole and the attracted portion. A circuit breaker that automatically shuts off by the operation performed, and is provided with a low-instrument circuit breaker in which the fixed iron core is provided with a magnetically amplified component called an auxiliary iron core having a simple shape.
[Feature 21]
Rather than adopting a proportional suction force increasing method that increases the facing area between the movable iron core and the fixed iron core as in the past, it features a square proportional suction force increasing method by reducing the initial gap. And Further, in order to reduce the initial gap between the movable core portion and the fixed core without reducing the tripping stroke of the movable core, the auxiliary core is turned into the inside of the fixed core and is turned. In addition, when changing the specifications of a low-instrument circuit breaker from the standard model, it is possible to provide an inexpensive circuit breaker with only one change.

  In addition, in each figure of FIGS. 1-7, the same code | symbol shows the same or an equivalent part.

20 circuit breaker, 21 base,
22 cover, 23 power supply side terminal,
24 trip device, 25 mover holder,
26 mounting screws, 27 opening / closing mechanism,
28 Load side terminal, 31 Fixed iron core,
31a Spring latch piece, 31b Leg,
31c bridge, 31d side wall,
31e contact surface (end face of magnetic pole), 31f magnetic pole,
31fe magnetic pole side surface, 31g stopper,
32 heater conductor, 32a female thread,
32b heater section, 33 thermal element (bimetal),
34 rivets, 35 adjustment screws,
36 stop nuts, 37 movable iron core 37a to be attracted portion (movable piece), 37b bearing portion,
37c Operation piece, 38 Return spring,
39 Shaft, 41 Auxiliary iron core, * Embodiment 1
41a Rectangular cutout 42 Auxiliary iron core (Embodiment 2),
51 Movable iron core (movable iron core + auxiliary iron core) (Embodiment 1),
A Initial gap between the movable iron core and the fixed iron core,
B1 Initial gap between the auxiliary iron core and the movable iron core (Embodiment 1),
B2 Initial gap between the auxiliary iron core and the movable iron core (Embodiment 2).

Claims (10)

In a circuit breaker comprising a magnetic movable iron core and a magnetic fixed iron core having a magnetic pole facing the attracted portion of the movable iron core, and automatically shutting off by an operation in which the movable iron core is attracted to the stationary iron core, the movable iron core A magnetic auxiliary iron core is provided on the magnetic pole side of the fixed iron core so as to be opposed to the magnetic pole of the fixed iron core and constitutes a movable iron core portion with the movable iron core. A circuit breaker that automatically shuts off the movable core portion by an action of being attracted to the fixed core by a magnetic attraction force generated between the magnetic pole and the auxiliary iron core.
The length B in the opposite direction of the initial gap between the auxiliary iron core and the magnetic pole of the fixed iron core is equal to the length of the initial gap between the movable iron core and the magnetic pole of the fixed iron core. An auxiliary iron core that is shorter than the length A in the opposite direction and reduces the initial gap between the movable iron core portion and the fixed iron core without reducing the tripping stroke of the movable iron core portion;
The movable core portion is pivotally attached to the fixed iron core at an intermediate portion thereof, and has an operation piece portion for performing a circuit breaker trip at one of both ends spaced from the pivoted portion. In a non-attraction operation state in which the attracted portion is not attracted magnetically to the magnetic pole, the opposing gap length between the attracted portion and the magnetic pole end surface on the attracted portion side of the magnetic pole is , Long enough to move away from the pivoted part,
In a non-attraction operation state where the attracted part is not attracted to the magnetic pole, the facing gap length between the auxiliary iron core and the magnetic pole is substantially constant within the entire range where the auxiliary iron core and the magnetic pole are opposed to each other. And
The circuit breaker , wherein the auxiliary iron core is not in contact with the fixed iron core in a state where the attracted portion is magnetically attracted to the magnetic pole . The circuit breaker according to claim 1,
The circuit breaker, wherein the movable iron core and the auxiliary iron core are integrated. The circuit breaker according to claim 2,
The circuit breaker characterized in that the movable iron core and the auxiliary iron core are separate, and the separate movable iron core and the auxiliary iron core are integrated by a coupling means. In the circuit breaker as described in any one of Claims 1-3,
The circuit breaker characterized in that the tripping stroke of the movable core before the auxiliary iron core is provided and the tripping stroke of the movable iron core after the auxiliary iron core is provided. In the circuit breaker as described in any one of Claims 1-4,
The circuit breaker characterized by the fact that the initial gap between the movable iron core and the fixed iron core is shorter after the auxiliary iron core is provided than before the auxiliary iron core is provided. In the circuit breaker according to any one of claims 1 to 5,
The fixed iron core is composed of a pair of side wall portions facing each other at a predetermined distance, and a bridging portion that bridges one end of each of the pair of side wall portions,
A conductor through which a load current flows is surrounded by the pair of side wall portions and the bridge portion and disposed near the bridge portion,
The circuit breaker characterized in that the other opposite ends of each of the pair of side wall portions are the magnetic poles. The circuit breaker according to claim 6,
The movable iron core is opposed to an end surface opposite to the bridging portion of the magnetic poles at the other ends opposite to each other,
The circuit breaker according to claim 1, wherein the auxiliary iron cores are opposed to mutually opposing side surfaces of the magnetic poles opposed to each other. The circuit breaker according to claim 6,
A surface obtained by virtually extending an end surface of the magnetic pole facing each other opposite to the bridging portion and a surface obtained by virtually extending the surface of the auxiliary iron core on the bridging portion side are not the same plane or parallel to each other. There is no circuit breaker. The circuit breaker according to claim 6,
A surface obtained by virtually extending an end surface of the magnetic pole opposite to the bridging portion and a surface obtained by virtually extending a surface of the auxiliary iron core on the bridging portion side are the same or parallel to each other . circuit breaker according to claim certain <br/> that. The circuit breaker according to any one of claims 6 to 9 ,
The auxiliary iron core is disposed between a pair of side wall portions of the fixed iron core;
The circuit breaker , wherein a width of the auxiliary iron core in a facing direction of the pair of side wall portions of the fixed core is narrower than a width of the suctioned portion in the facing direction of the pair of side wall portions .

Images