JP4094155B2 - Circuit breaker and overcurrent trip device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a thermal-electromagnetic circuit breaker incorporated in a circuit breaker for wiring and the like and an overcurrent tripping device thereof .
[0002]
[Prior art]
FIG. 6 is an exploded perspective view showing an overcurrent tripping device for a conventional circuit breaker disclosed in, for example, Japanese Utility Model Laid-Open No. 3-19236. In the figure, 1 is a heater assembly, and a U-shaped fixed magnet 3 and a bimetal 4 are integrally fixed to a heater 2 made of an L-shaped conductor by a rivet 5. Reference numeral 6 denotes an armature, and a pair of arms 6a formed on both sides so as to face the fixed magnet 3 are fitted in receiving grooves 7a of a case 7 of a circuit breaker, and are rotatably supported. 8 is a return Sprint grayed, a spring hook holes 6b formed in the armature 6, both ends of the return spring 8 is hooked on the spring hanging hook 3a formed in the fixed magnet 3, the armature 6 is urged to the return spring 8 Thus, the lower end portion 6 c is held at a fixed position in contact with the stopper 7 c of the case 7. At this time, the armature 6 is urged by the return spring 8 so as not to come out of the receiving groove 7a. In addition, the heater assembly 1 is fixed to the bottom of the case 7 by the L-bending portion 2 a of the heater 2 from the back side of the case 7 with a mounting screw 9.
[0003]
In such an overcurrent tripping device for a conventional circuit breaker, in order to attach the overcurrent tripping device to the case 7, first, the heater assembly 1 is fixed to the case 7 with the mounting screw 9, and then The armature 6 is inserted into the case 7, and thereafter, the return spring 8 is attached between the armature 6 and the heater assembly 1.
[0004]
[Problems to be solved by the invention]
In the conventional overcurrent tripping device for a circuit breaker as described above, after fixing the heater assembly 1 to the case 7, the armature is placed in a very narrow space of the case 7 in which the heater assembly 1 is incorporated. 6 and the return spring 8 must be assembled sequentially, so that the assembly work is very difficult and takes time.
[0005]
Further, in the inspection of the finished product after the assembly as a circuit breaker, when the characteristic failure or the assembly error occurs and the armature 6 and the return spring 8 must be removed in order to replace the return spring 8, the return spring 8 There is also a problem in that it is difficult to replace the return spring 8 because there is a possibility that the spring characteristics may be changed by applying a force greater than the stress due to excessive tension.
[0006]
The present invention has been made to solve the above-described problems, and a first object is to fix the heater assembly to the case and then assemble the armature and the return spring in a narrow space of the case. in which to obtain an overcurrent trip device easy circuit breaker and its.
[0007]
A second object is, if defective characteristics and assembling errors is required, such as in replacement of the return spring, replacing the return spring without changing the spring characteristics easy circuit breaker and overcurrent trip device of its To get.
[0008]
[Means for Solving the Problems]
In the overcurrent tripping device for a circuit breaker according to the present invention, a fixed magnet and a bimetal are integrally fixed to a heater made of a conductor and fixed to a case of the circuit breaker, and the fixed magnet is opposed to the heater assembly. An armature that has a movable piece and a pair of arm portions that are pivotably supported by the groove portion of the case and is detachably supported , and a return that engages between the armature and the fixed magnet. In an overcurrent tripping device for a circuit breaker comprising a spring, a shaft portion formed continuously with one arm portion of the armature , into which a coil portion of the return spring is inserted, and one of the return springs and a first spring hooking portion for hooking the legs provided in the armature, set a spring engaging portion engaging the other leg of the return spring to the stationary magnet Those were.
[0009]
Further, the armature is provided with a second spring hook portion on which the other leg of the return spring is temporarily hooked.
[0010]
Furthermore, the cover which covers the case is provided with a stopper which prevents the armature from coming out of the groove portion of the case. Also, a case, a cover covering the case, a fixed contact fixed to the case, and a movable contact arranged to face the fixed contact so as to be able to contact and separate from the fixed contact A heater assembly that is electrically connected to the movable contact and is fixed to the case, wherein a fixed magnet and a bimetal are integrally fixed to a heater made of a conductor, and a movable piece that faces the fixed magnet, It has a pair of arm parts, and these arm parts are engaged with the armature rotatably supported by the groove formed in the case and detachably supported between the armature and the fixed magnet. And a return spring for inserting the coil portion into one arm portion of the armature, hooking one leg to the armature, and setting the other foot to the armature. To a constant magnet is obtained so as to hook.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
FIG. 1 is a perspective view showing a principal part of an overcurrent tripping device for a circuit breaker according to a first embodiment of the present invention. FIG. 2 is an exploded perspective view of the overcurrent tripping device for the circuit breaker shown in FIG. FIG. 3 is a longitudinal sectional view of a circuit breaker incorporating the overcurrent tripping device shown in FIG.
[0012]
In the figure, 10 is a case made of a synthetic resin material, and has a pair of groove portions 10a (only one is shown in FIGS. 1 and 2) to which a pair of arm portions 16c of an armature 16 described later is mounted. ing. Reference numeral 11 denotes a heater assembly. A fixed magnet 13 is fixed to one side of the heater 12 and a bimetal 14 is fixed to the other side by a rivet 15.
[0013]
The heater 12 is formed by bending a conductor, and includes a load side terminal portion 12a, a heater portion 12b that is sandwiched between the fixed magnet 13 and the bimetal 14, and heats the bimetal 14, and a heater mounting portion 12c that is fixed to the case 10. is doing. The fixed magnet 13 is formed of a magnetic material in a substantially U shape, and has a pair of magnetic poles 13a facing an armature 16 described later, and a spring engaging portion 13b engaged with a foot 18c of a return spring 18 described later. ing. Reference numeral 14 denotes a plate-like thermal element, that is, a bimetal.
[0014]
Reference numeral 16 denotes an armature, a pair of movable pieces 16a facing the fixed magnet 13, a first spring hooking portion 16b protruding in a hook shape in a direction opposite to the fixed magnet 13 from a substantially central lower end portion of the movable piece 16a, A pair of arm portions 16c formed to protrude left and right above the movable piece 16a and rotatably supported by the pair of groove portions 10a of the case 10, and a return spring 18 which is continuously formed on one arm portion 16c and which will be described later. A shaft portion 16d into which the coil portion 18a is inserted and an operation piece 16e that extends upward from substantially the center of the pair of arm portions 16c and presses a trip bar 25a described later during a trip operation.
[0015]
18 single torsion type of the torsion coil spring, that is, the return spring, a coil portion 18a which is tightly wound, a pair of legs 18 b, 18 c, engagement between the armature 16 and the stationary magnet 13, Normally, the armature 16 is urged in a direction to separate it from the fixed magnet 13.
[0016]
In FIG. 3, 19 is a cover that covers the case 10 made of synthetic resin, 20 is a power supply side terminal, 21 is a fixed contact fixed to the case 10, and 22 is a movable that contacts and separates from the fixed contact 21. It is a contact. Reference numerals 23 and 24 denote a flexible conductor and a connection conductor for electrically connecting the movable contact 22 and the heater assembly 11. Reference numeral 25 denotes an opening / closing mechanism, which has a trip bar 25a. Reference numeral 26 denotes a mounting screw.
[0017]
A method of incorporating the overcurrent tripping device for a circuit breaker configured as described above into the case 10 will be described with reference to FIGS.
First, the heater assembly 11 is inserted into the case 10, and the connection conductor 24 (shown in FIG. 3) is sandwiched between the heater mounting portion 12 c and the case bottom surface 10 b, and fixed from the back side of the case 10 with mounting screws 26.
[0018]
Next, in order to incorporate the return spring 18 into the armature 16, the coil portion 18 a of the return spring 18 is inserted into the shaft portion 16 d of the armature 16, and one leg 18 b of the return spring 18 is connected to the first spring of the armature 16. Hang on the hook 16b.
[0019]
Next, in order to incorporate the armature 16 to which the return spring 18 is attached into the case 10 to which the heater assembly 11 is attached, the return spring 18 inserted into the shaft portion 16d of the armature 16 is used. While holding the other foot 18c by hand and rotating it counterclockwise, the armature 16 reaches a position where the pair of arm portions 16c of the armature 16 fits in the pair of groove portions 10a of the case 10. Insert. When the hand holding the other foot 18c of the return spring 18 is released at this position, the other foot 18c rotates clockwise to engage with the spring engaging portion 13b of the fixed magnet 13, and the armature 16 and The assembly of the return spring 18 is completed, and the assembly of the overcurrent tripping device is completed. Then, the circuit breaker is completed by covering the cover 19.
[0020]
In the circuit breaker configured as described above, in FIG. 3, the overload current is generated when the power source side terminal 20 → the fixed contact 21 → the movable contact 22 → the flexible conductor 23 → the connection conductor 24 → the heater mounting portion 12 c → When flowing through the path from the heater portion 12b to the load side terminal 12a, the bimetal 14 is heated by the heat generated by the heater portion 12b, and the tip portion 14a of the bimetal 14 is bent in the direction of arrow A as shown in FIG. By this bending, the trip bar 25a is pushed by the tip end portion 14a of the bimetal 14, and the opening / closing mechanism portion 25 operates to trip the circuit breaker.
[0021]
Further, when a large current such as a short-circuit current flows through the heater section 12b, the fixed magnet 13 is magnetized, and the movable piece 16a of the armature 16 is instantaneously attracted to the magnetic pole 13a, and the operation piece 16e of the armature 16 is rotated clockwise. Move. By this rotation, the operating piece 16e of the armature 16 pushes the trip bar 25a to trip the circuit breaker in the same manner as described above, and performs a known breaking operation.
[0022]
In the overcurrent tripping device for a circuit breaker configured in this way, the armature 16 inserted in a predetermined mounting position is always pressed against the groove 10a of the case 10 by the return spring 18 at the pair of arm portions 16c. Thus, it is prevented from coming out of the groove portion 10a of the case 10 during vibration of the circuit breaker and rotation during the suction operation of the armature 16.
[0023]
Further, when the armature 16 is removed from the case 10, the return spring 18 can be detached from the spring hook 13 a of the fixed magnet 13 and simply removed from the case 10 simply by pulling the armature 16 upward.
When the armature 16 is attached to the case 10 again, it can be easily attached in the same manner as the above-described method for assembling the armature 16.
[0024]
According to the configuration of the first embodiment, when the overcurrent tripping device is assembled in the case 10, the assembly work of the armature 16 and the return spring 18 is performed even in a very narrow space of the case 10 in which the heater assembly 11 is incorporated. Becomes easier.
In addition, when the circuit breaker is inspected for a finished product, defective characteristics, assembly errors, etc. occur, and if the return spring 18 is to be replaced, there is a risk that the return spring 18 will be pulled too much and a force exceeding the stress will be applied to change the spring characteristics. In addition, the return spring 18 can be easily replaced, the instantaneous tripping characteristic can be corrected in a short time, and the assembly time loss can be greatly improved.
[0025]
Embodiment 2. FIG.
FIG. 4 is a perspective view showing an armature portion of an overcurrent tripping device for a circuit breaker according to Embodiment 2 of the present invention. In the figure, reference numeral 16f denotes a second spring hook portion that is formed so as to protrude from the surface opposite to the first spring hook portion 16b of the armature 16, and can temporarily hook the other leg 18c of the return spring 18. it can. The overcurrent tripping device and the circuit breaker in which the armature 16 shown in FIG. 4 is incorporated are the same as those shown in FIGS. 1 and 3, and the illustration and description thereof are omitted.
[0026]
In order to incorporate the armature 16 and the return spring 18 into the case 10 to which the heater assembly 11 is fixed, the armature 16 assembled as shown in FIG. 4 is paired with the armature 16 in the groove 10 a of the case 10. Until the arm portion 16c is fitted.
[0027]
Next, when the other leg 18c of the return spring 18 temporarily suspended by the second spring hook 16f of the armature 16 is removed from the second spring hook 16f with a finger or a pin, it automatically returns. other leg 18c of the spring 18 engages the spring engaging portion 13 b of the stationary magnet 13, the movable piece 16a of the armature 16 against the stopper 10c of the case 10 by the biasing force of the return spring 18 (shown in FIG. 1) In contact therewith, it is assembled at a predetermined mounting position.
[0028]
According to the configuration of the second embodiment, since the armature 16 is provided with the second spring hooking portion 16f on which the other leg 18c of the return spring 18 is temporarily hooked, before the armature 16 is inserted into the case 17 The return spring 18 can be held by the armature 16 and, as described in the first embodiment, it is not necessary to insert the groove into the groove 10a of the case 10 while holding the other leg 18c of the return spring 18 by hand. Even when the return spring 18 having a strong spring load is required, it can be easily assembled, and the assembly workability is further improved.
[0029]
Embodiment 3 FIG.
FIG. 5 is a perspective view showing the overcurrent tripping device for a circuit breaker according to the third embodiment of the present invention, with the main part broken away. In the figure, reference numeral 19a denotes a protrusion or stopper provided so as to protrude inward from the side wall of the cover 19, and the armature 16c of the armature 16 inserted into the groove 10a of the case 10 does not come out upward. It is formed so as not to prevent the rotation of 16.
[0030]
In the first embodiment, the armature 16 receives a downward force by the return spring 18 and is rotatably supported by the groove 10 a of the case 10 . This prevents the armature 16 from slipping out of the groove 10a of the case 10 during vibration of the circuit breaker or rotation during the suction operation of the armature 16, but the armature 16 is configured to be easily removed. In the unlikely event that an upward force greater than the removal force acts on the armature 16, the groove 10 a may be pulled out. In particular, in the case of a circuit breaker for low rated current using the return spring 18 having a weak spring load, the possibility that the armature 16 will come out of the groove 10a is increased.
[0031]
According to the configuration of the third embodiment, the armature 16 is removed from the groove portion 10a of the case 10 by a strong electromagnetic force acting on the armature 16 when a large vibration applied to the circuit breaker or a large current such as a short circuit current is interrupted. prevent the break out, during the suction operation, the armature 16 can smoothly pivoted to Rukoto, it is possible to obtain an overcurrent trip device of a circuit breaker having a stable overcurrent tripping characteristic.
[0032]
【The invention's effect】
Since the present invention is configured as described above, the following effects can be obtained.
[0033]
A spring mechanism in which a shaft portion for inserting the coil portion of the return spring into the armature and a first spring hook portion for hooking one leg of the return spring are provided, and the other leg of the return spring is engaged with the fixed magnet. Since the joint is provided, the armature is inserted into the case together with the return spring, and when the other leg of the return spring is released, this foot engages with the spring engaging part of the fixed magnet, so the case is very narrow The assembly work of the armature and the return spring is facilitated even in the space.
In addition, when a circuit breaker is inspected for finished products, defective characteristics, assembly errors, etc. occur, and if you want to replace the return spring, simply pull the armature upward and the return spring will come out of the spring engaging part of the fixed magnet. Since it can be easily removed, the return spring can be easily exchanged without excessively pulling the return spring and applying a force exceeding the stress to change the spring characteristics.
[0034]
In addition, the armature is provided with a second spring hook that temporarily holds the other leg of the return spring so that it can be held before the armature is assembled into the case, and the other leg of the return spring is held by hand. However, it is no longer necessary to install it in the case, and the assembly work becomes easier.
[0035]
Furthermore, the cover covering the case, since the armature is provided with a stopper to prevent the escape from the groove of the case, a strong acting on the armature during interruption of large current such as a large vibration, or short-circuit current applied to the circuit breaker Electromagnetic force prevents the armature from coming out of the groove of the case.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a perspective view showing a principal part of an overcurrent tripping device for a circuit breaker according to a first embodiment of the present invention in a cutaway manner.
2 is an exploded perspective view of the overcurrent tripping device for the circuit breaker shown in FIG. 1. FIG.
FIG. 3 is a longitudinal sectional view of a circuit breaker incorporating the overcurrent tripping device shown in FIG.
FIG. 4 is a perspective view showing an armature portion of an overcurrent tripping device for a circuit breaker according to a second embodiment of the present invention.
FIG. 5 is a perspective view showing an overcurrent tripping device for a circuit breaker according to a third embodiment of the present invention, with a main part cut away.
FIG. 6 is an exploded perspective view showing an overcurrent tripping device for a conventional circuit breaker.
[Explanation of symbols]
10 Case, 10a Groove, 11 Heater assembly, 12 Heater,
12b heater section, 13 fixed magnet, 13a magnetic pole ,
Bimetal, 16 armature, 16a movable piece,
16b 1st spring hook part, 16d shaft part, 16f 2nd spring hook part,
18 return spring, 18a coil part, 18b, 18c foot,
19 Cover, 19a Stopper.

Claims (4)

A heater assembly comprising a fixed magnet and a bimetal fixed integrally to a heater made of a conductor and fixed to a case of a circuit breaker, a movable piece facing the fixed magnet, and a pair of arm portions, In an overcurrent tripping device for a circuit breaker comprising an armature that is rotatably and removably supported in a groove of the case , and a return spring that engages between the armature and the fixed magnet. A shaft portion formed continuously with one arm portion of the armature , into which the coil portion of the return spring is inserted, and a first spring hook portion for hooking one leg of the return spring are attached to the armature. An overcurrent tripping device for a circuit breaker, characterized in that a spring engaging portion for engaging the other leg of the return spring is provided on the fixed magnet.   2. An overcurrent tripping device for a circuit breaker according to claim 1, wherein the armature is provided with a second spring hook portion on which the other leg of the return spring is temporarily hooked.   The overcurrent tripping device for a circuit breaker according to claim 1 or 2, wherein a stopper for preventing the armature from coming out of the groove of the case is provided on the cover covering the case. A case, a cover covering the case, a fixed contact fixed to the case, a movable contact disposed so as to face the fixed contact, and capable of contacting and separating from the fixed contact; A heater assembly that is electrically connected to the movable contact and is fixed to the case, wherein a fixed magnet and a bimetal are integrally fixed to a heater made of a conductor, a movable piece that faces the fixed magnet, and a pair of An arm that has arm portions, and these arm portions are rotatably supported in a groove formed in the case and are detachably supported, and a return that engages between the armature and the fixed magnet. The return spring has a coil portion inserted into one arm portion of the armature, one leg hooked to the armature, and the other foot fixed to the fixed arm. Circuit breaker being characterized in that so as to hook into the net.

Images