JP4487429B2 - Circuit breaker overcurrent trip device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a thermal-electromagnetic overcurrent tripping device incorporated in a circuit breaker for wiring.
[0002]
[Prior art]
FIG. 6 is a perspective view of a main part of an overcurrent tripping device for a conventional circuit breaker disclosed in, for example, Japanese Patent Application Laid-Open No. 2000-231870. FIG. 7A is an exploded perspective view of FIG. 6, and FIG. 7B is a state diagram in which a return spring is temporarily fixed to the armature.
[0003]
6 and 7, reference numeral 1 denotes a heater assembly 2 in which a substantially U-shaped fixed magnet 3 and a bimetal 4 are integrally fixed to a heater 2 made of a conductor, and 5 is a magnetic pole of the fixed magnet 3. An armature that includes a movable piece 5a disposed opposite to 3a and protrudes left and right above the movable piece 5a and is inserted into a pair of groove portions 6a disposed in the case 6 and pivotally supported. Reference numeral 6 b denotes a stopper provided on the case 6, 7 denotes a return spring that engages the armature 5 and the fixed magnet 3 to urge the armature 5, and 8 denotes a tightening screw that fixes the heater assembly 1 to the case 6.
[0004]
The armature 5 includes a shaft portion 5c into which the coil portion 7a of the return spring 7 is inserted, a first spring hook portion 5d for hooking one leg 7b of the return spring 7, and a first pin for temporarily fixing the other leg 7c. The fixed magnet 3 includes a spring hook hook 3b that holds the other leg 7c of the return spring 7 at the upper position.
[0005]
Next, a method of incorporating the overcurrent tripping device for the conventional circuit breaker formed as described above into the circuit breaker will be described.
(1) The heater assembly 1 is fixed to the case 6 with the fastening screw 8.
(2) The coil portion 7 a of the return spring 7 is inserted into the shaft portion 5 c of the armature 5.
[0006]
(3) One leg 7b of the return spring 7 is latched to the first spring hook part 5d of the armature 5, and the other leg 7c is temporarily fastened to the second spring hook part 5e (FIG. 7B). .
(4) The arm 5 b on both sides of the armature 5 is inserted into the groove 6 a of the case 6.
(5) Pull the other leg 7c of the return spring 7 to the front side of FIG. 7B to release it from the second spring hooking portion 5e.
[0007]
(6) As a result of the above, the other leg 7c of the return spring 7 is held by the spring hook portion 3b disposed at the upper position of the fixed magnet 3, and the armature 5 receives the urging force of the return spring 7, The groove 6a is pivotally supported and abuts against a stopper 6b provided on the case 6, and the overcurrent tripping device is accommodated in the case 6 (FIG. 6).
[0008]
[Problems to be solved by the invention]
Since the overcurrent tripping device of the conventional circuit breaker is formed as described above, when the armature 5 and the return spring 7 are assembled, the return spring 7 is temporarily attached to the armature 5 and inserted into the case 6. After that, it is necessary to remove the temporary fixing of the other leg 7c of the return spring 7 from the second spring hooking portion 5e, and the other leg 7c is in the position of the back. It was very difficult to remove the foot 7c from the second spring hook 7e.
[0009]
The present invention has been made to solve such problems, and an object thereof is to obtain an overcurrent tripping device for a circuit breaker that can be easily incorporated.
[0010]
[Means for Solving the Problems]
An overcurrent tripping device for a circuit breaker according to the present invention has a heater assembly in which a fixed magnet and a bimetal are integrally fixed to a heater made of a conductor and fixed to a case, and a movable piece facing the fixed magnet. An overcurrent tripping circuit breaker having an armature pivotally supported and a return spring fixedly attached to the armature and energizing the movable piece of the armature away from the fixed magnet. In the device, the armature includes a first spring hook portion that holds one leg of the return spring and a second spring hook portion that temporarily holds the other leg of the spring before pivotally pivotally supported. And when the armature is pivotally supported, the other leg engages with the protrusion and is released from temporary fixing.
[0011]
The arm assembly includes a heater assembly in which a fixed magnet and a bimetal are integrally fixed to a heater made of a conductor and fixed to a circuit breaker case, a movable piece facing the fixed magnet, and a pair of arm portions. Is inserted into the groove of the case and is pivotally supported, and a return spring that engages the armature and the fixed magnet to urge the movable piece of the armature away from the fixed magnet. In the circuit breaker overcurrent tripping device, the armature includes a shaft portion into which the coil portion of the return spring is inserted, a first spring hook portion that latches one leg of the return spring, and A second spring hook portion for temporarily fixing the other leg of the spring, and the fixed magnet has an arm portion of the armature in the case. A projection that presses the other foot when it is inserted into the groove and releases it from temporary fixing with the second spring hook, and a spring hook that holds the released other foot in place It has a hook.
[0012]
Further, the contact surface of the protruding portion that engages with the other leg of the return spring is a slope.
[0013]
Also, the other leg of the return spring is bent.
[0014]
Further, the coil portion of the return spring is tapered, and the shaft portion of the armature is tapered so as to be inscribed in the coil portion.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
1 is a perspective view of an essential part of an overcurrent tripping device for a circuit breaker according to Embodiment 1 of the present invention. FIG. 2 is an exploded perspective view of the overcurrent tripping device of FIG. FIG. 3 is a cross-sectional perspective view of a circuit breaker incorporating the overcurrent tripping device shown in FIG. 4 is an exploded perspective view of the fixed magnet, the armature, and the return spring shown in FIG. 1 as viewed from the back side, where (a) is a state in which the return spring is temporarily fixed to the armature, (b) is a fixed magnet, and (c) is The assembled state is shown.
[0016]
In FIGS. 1, 2 and 4, reference numeral 11 denotes a heater assembly in which a fixed magnet 13 and a bimetal 14 which is a plate-like thermal element are fixed to a heater 12 made of a conductor by a rivet 15, and the heater 12 is a load side terminal portion 12a ( 2), a heater portion 12b (shown in FIG. 2) that is sandwiched between the fixed magnet 13 and the bimetal 14 and heats the bimetal 14, and a tap portion 12c (see FIG. 2) for fixing the heater assembly 11 to the case 17. 2).
[0017]
The fixed magnet 13 is formed in a substantially U shape with a magnetic material such as an iron plate, for example, and a pair of magnetic poles 13a (shown in FIG. 2) disposed opposite to an armature 16 described later, and a return spring 18 described later. A protrusion 13b (shown in FIG. 4) having an inclined surface portion 13c that contacts when the other foot 18c is assembled into the case 10, and a spring hook 13d (see FIG. 4) that holds the other foot 18c of the return spring 18 after being assembled into the case 17. 4).
[0018]
Reference numeral 16 denotes a pair of movable pieces 16a (shown in FIG. 2) disposed to face the fixed magnet 13, and protrudes in a substantially L shape at a substantially central lower portion of the movable piece 16a. A first spring hooking portion 16b for hooking 18b, and protruding to the left and right at the upper position of the movable piece 16a are inserted into a pair of groove portions 17a disposed in a case 17 described later and are pivotally supported. A pair of arm portions 16c, a shaft portion 16d into which a coil portion 18a of a return spring 18 to be described later is inserted, and extending upward from substantially the center of the pair of arm portions 16c, will be described later when the circuit breaker is tripped. An armature having an operation piece 16e for pressing the trip bar 25a (shown in FIG. 3) and a second spring hooking portion 16f (shown in FIG. 4) for temporarily fixing the other leg 18c of the return spring 18 described later. That.
[0019]
17 is formed of, for example, a synthetic resin molding material, a pair of groove portions 17a (only one is shown in FIGS. 1 and 2) into which the pair of arm portions 16c of the armature 16 are inserted, and the movable piece 16a of the armature 16 This is a case provided with a stopper 17b for limiting rotation and a bottom portion 17c.
[0020]
A coil portion 18a (shown in FIG. 2), which is formed by a torsion coil spring, is composed of one leg 18b, the other leg 18c, and a bent portion 18d, and is engaged between the armature 16 and the fixed magnet 13. The return spring urges the movable piece 16a of the armature 16 away from the magnetic pole 13a of the fixed magnet 13.
[0021]
In FIG. 3 showing the circuit breaker incorporating the overcurrent tripping device formed as described above, 19 is a cover formed of, for example, a synthetic resin molding material and covers the case 17 from the upper surface, 20 is a power supply side terminal, 21 is a fixed contact fixed to the case 17, 22 is a movable contact that contacts and separates from the fixed contact 21, 23 and 24 are movable contact holders that electrically connect the movable contact 22 and the heater assembly 11, The connection conductor, 25 is an opening / closing mechanism having a trip bar 25a, and 26 is a tightening screw for tightening and fixing the heater assembly 11 to the case 17.
[0022]
Next, a method for incorporating the circuit breaker overcurrent tripping device according to Embodiment 1 of the present invention configured as described above into the circuit breaker will be described with reference to FIGS.
[0023]
(1) Insert the heater assembly 11 into the case 17, clamp the connection conductor 24 between the tap portion 12 c of the heater 12 and the bottom portion 17 c of the case 17, and tighten from the back side of the case 17 (downward in FIG. 3). Secure with screws 26.
[0024]
(2) The coil portion 18a of the return spring 18 is inserted into the shaft portion 16d of the armature 16 in the direction of arrow A (shown in FIG. 2), and one leg 18b of the return spring 18 is inserted into the first spring hook 16b of the armature 16. And the other leg 18c is temporarily fixed to the second spring hook 16f. (Fig. 4 (a))
[0025]
(3) The pair of arm portions 16c of the armature 16 fitted with the return spring 18 formed in (2) is inserted into the pair of groove portions 17a formed in the case 17 in the arrow B direction (shown in FIGS. 2 and 4). To do.
[0026]
(4) The bent portion 18d of the other leg 18c of the return spring 18 temporarily fixed to the second spring hooking portion 16f of the armature 16 is pressed by the inclined surface portion 13c of the protruding portion 13b provided on the fixed magnet 13. As a result, the other leg 18c is deformed in the direction of arrow C (shown in FIG. 4), and the other leg 18c of the return spring 18 that is temporarily fixed to the second spring hook 16f becomes the second spring hook 16f. Deviate from.
[0027]
(5) The other leg 18c of the return spring 18 released from the second spring hook 16f is in contact with and held by the spring hook 13d provided on the fixed magnet 13 (FIG. 4C).
(6) The armature 16 receives the urging force of the return spring 18 in a state where the arm portion 16c is pivotally supported by the groove portion 17a of the case 17, and abuts against the stopper 17b disposed on the case 17 to overcurrent. The tripping device is stored in a predetermined mounting position of the circuit breaker (FIG. 1).
(7) Cover 19 is placed on the upper surface of case 17 to complete the circuit breaker (FIG. 3).
[0028]
When the armature 16 is removed from the case 17, the other leg 18 c of the return spring 18 is connected to the spring hook 13 d of the fixed magnet 13 only by pulling the operation piece 16 e of the armature 16 in the direction of arrow D (shown in FIG. 1). Can be removed from the case 17 easily.
[0029]
Next, the tripping operation of the circuit breaker according to the first embodiment configured as described above will be described with reference to FIGS.
(1) The overload current is energized through the path of the power source side terminal 20 → the stationary contact 21 → the movable contact 22 → the mover holder 23 → the connection conductor 24 → the tap portion 12c → the heater portion 12b → the load side terminal 12a.
[0030]
(2) The heater portion 12b generates Joule heat due to current application, the bimetal 14 is heated, and the tip portion 14a of the bimetal 14 is bent in the direction of arrow E (shown in FIG. 3).
(3) Due to this bending, the tip 14a of the bimetal 14 presses the trip bar 25a, and the opening / closing mechanism 25 performs a trip operation, whereby the movable contact 22 is separated from the fixed contact 21 and cuts off the current. .
[0031]
(4) Similarly, when a large current such as a short-circuit current flows, the fixed magnet 13 is magnetized by the magnetic flux generated by this current, and the movable piece 16a of the armature 16 is instantaneously attracted to the magnetic pole 13a. The operation piece 16e rotates in the direction of arrow F (shown in FIG. 1) with the arm portion 16c as a fulcrum.
(5) By this rotation, the operating piece 16e of the armature 16 pushes the trip bar 25a and cuts off the current in the same manner as the above-described process.
[0032]
As described above, according to the overcurrent tripping device for the circuit breaker according to the first embodiment of the present invention, even when the overcurrent tripping device is assembled in the circuit breaker, even in a very narrow space in the case 17. By simply inserting the arm portion 16c of the armature 16 to which the return spring 18 is temporarily fixed into the groove portion 17a of the case 17, the temporarily fixed return spring 18 is held at a predetermined position of the fixed magnet 13, so that an overcurrent tripping device is provided. Assembling work can be facilitated.
[0033]
In the above-described embodiment, the groove portion 17 a that pivotally supports the arm portion 16 c of the armature 16 is disposed in the case 17, but may be disposed in the fixed magnet 13.
[0034]
Further, in the above embodiment, the fixed magnet 13 is provided with the protrusion 13b that presses the other foot 18c of the return spring 18 and releases the temporary fixing from the second spring hook 16f, and the spring hook 13d. May be provided.
[0035]
Furthermore, in the above-described embodiment, the one-pole overcurrent tripping device formed by the heater assembly 11, the armature 16 and the return spring 18 is incorporated in the circuit breaker case 17. It is also possible to add a sub case in which the removing device is housed and each is provided with the groove portion 17 a, and form an overcurrent tripping device housed in the sub case as a unit so as to be incorporated in the case 17.
[0036]
Embodiment 2. FIG.
FIG. 5 is an exploded perspective view of an armature and a return spring of an overcurrent tripping device for a circuit breaker according to Embodiment 2 of the present invention.
In the figure, 160 is an armature, 180 is a return spring, the coil portion 180a of the return spring 180 has a tapered shape, and the shaft portion 160d of the armature 160 into which the coil portion 180a is inserted is a taper inscribed in the coil portion 180a. Form a shape.
[0037]
The circuit breaker overcurrent tripping device formed as described above is assembled in the same manner as in the first embodiment described above, but when the coil portion 180a of the return spring 180 is inserted into the shaft portion 160d of the armature 160, the coil breaker Since the dimension of the insertion part of the part 180a is larger than the dimension of the shaft part 160d, the insertion operation is easy. Further, in the tripping operation due to the overcurrent, the shaft portion 160d of the armature 160 is inscribed in the coil portion 180a, so that the pivoting operation of the armature 160 is smooth and the tripping is performed reliably.
[0038]
【The invention's effect】
Since the present invention is configured as described above, the following effects can be obtained.
[0039]
According to the first aspect of the present invention, when the armature is pivotally supported, the return spring engages with the projection and is released from the temporary fixing, so that the overcurrent tripping device is easily assembled at a predetermined mounting position. be able to.
[0040]
According to the invention of claim 2, the shaft portion for inserting the coil portion of the return spring into the armature, the first spring hook portion for latching one leg of the return spring, and the second rod for latching the other leg. And a protrusion that presses the other leg and releases it from the latch with the second spring hook when the armature of the armature is inserted into the groove of the case on the fixed magnet, By providing a spring hook that holds the released other foot in place, the return spring is released from the temporary lock when the armature temporarily fixed to the return spring is inserted into the groove of the case. The current tripping device can be easily installed at a predetermined mounting position in the case of the circuit breaker.
Further, since there is no need for a work process for opening the other leg of the return spring as in the prior art, automatic assembly is also possible.
[0041]
According to the third aspect of the present invention, when the armature is inserted into the case, the contact surface of the protrusion that engages with the other leg of the return spring is inclined, so that the other leg is separated from the second spring hook. It is released smoothly.
[0042]
According to the invention of claim 4, since the other leg of the return spring is bent, the contact surface with the projection is wide and the other leg is reliably released from the second spring hook.
[0043]
According to the invention of claim 5, since the coil portion of the return spring is tapered and the shaft portion of the armature is tapered so as to be inscribed in the coil portion, the coil portion of the return spring is inserted into the shaft portion of the armature. In this case, since the dimension of the insertion part of the coil part is formed larger than the dimension of the shaft part, the insertion work is easy. Further, in the tripping operation due to overcurrent, the armature shaft portion is inscribed in the coil portion, so that the pivoting operation of the armature is smooth and the tripping is performed reliably.
[Brief description of the drawings]
FIG. 1 is a perspective view of an essential part of an overcurrent tripping device for a circuit breaker according to Embodiment 1 of the present invention.
2 is an assembled perspective view of the overcurrent tripping device shown in FIG. 1. FIG.
FIG. 3 is a cross-sectional view of a circuit breaker incorporating the overcurrent tripping device shown in FIG.
4 is an exploded perspective view showing an armature, a return spring and a fixed magnet of the overcurrent tripping device shown in FIG. 1. FIG.
FIG. 5 is an exploded perspective view of an armature and a return spring of an overcurrent tripping device for a circuit breaker according to Embodiment 2 of the present invention.
FIG. 6 is a perspective view of a main part of an overcurrent tripping device for a conventional circuit breaker.
7 is an exploded perspective view of the overcurrent tripping device shown in FIG. 6. FIG.
[Explanation of symbols]
11 heater assembly, 12 heater, 13 fixed magnet, 13a magnetic pole,
13b Projection part, 13c Inclined part, 13d Spring hook hook,
14 Bimetal, 14a Tip, 16,160 Armature,
16a movable piece, 16b first spring hook, 16c arm,
16d, 160d shaft portion, 16e operation piece, 16f second spring hooking portion,
17 Case, 17a Groove, 18, 180 Return spring,
18a, 180a coil part, 18b one leg, 18c the other leg,
18d Bending part.

Claims (5)

A heater assembly in which a fixed magnet and a bimetal are integrally fixed to a heater made of a conductor and fixed to a case;
An armature having a movable piece facing the fixed magnet and pivotally supported;
In an overcurrent tripping device for a circuit breaker comprising a return spring fixedly attached to the armature and energized so that the movable piece of the armature moves away from the fixed magnet,
The armature includes a first spring hook portion that holds one leg of the return spring and a second spring hook portion that temporarily holds the other leg of the spring before being pivotally supported. ,
An overcurrent tripping device for a circuit breaker, wherein when the armature is pivotally supported, the other leg engages with a protrusion and is released from temporary fixing. A heater assembly in which a fixed magnet and a bimetal are integrally fixed to a heater made of a conductor and fixed to a case of a circuit breaker;
An armature having a movable piece facing the fixed magnet and a pair of arm portions, the arm portions being inserted into the groove portions of the case and pivotally supported;
In an overcurrent tripping device for a circuit breaker comprising a return spring that engages with the armature and the movable piece of the armature to urge the armature away from the fixed magnet.
The armature includes a shaft portion for inserting the coil portion of the return spring,
A first spring hook for latching one leg of the return spring;
A second spring hook for temporarily fixing the other leg of the spring;
The fixed magnet has a projection that presses the other leg when the arm part of the armature is inserted into the groove of the case to release it from temporary fixing with the second spring hook part,
An overcurrent tripping device for a circuit breaker, comprising: a spring hook hook for holding the released other foot in a predetermined position. The overcurrent tripping device for a circuit breaker according to claim 1 or 2, wherein the contact surface of the protrusion engaging with the other leg of the return spring is a slope. The overcurrent tripping device for a circuit breaker according to any one of claims 1 to 3, wherein the other leg of the return spring is bent. The circuit breaker according to any one of claims 1 to 4, wherein the coil portion of the return spring is tapered and the shaft portion of the armature is tapered so as to be inscribed in the coil portion. Overcurrent trip device.

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