JPH0810924Y2 - Circuit breaker - Google Patents

Description

[Detailed Description of the Invention] [Technical Field to which the Invention belongs] The present invention relates to a circuit breaker for protecting an electric line and a load from a large current due to a short circuit of a commercial AC electric line,
In particular, the movable conductor is electromagnetic repulsive force due to the large current, and the contact spring of the high-speed opening type circuit breaker that can be opened without waiting for the operation of the separately provided opening mechanism is used. Regarding suspension structure.

[Conventional technology]

Conventionally, as the suspension structure of the movable conductor and the contact spring of the circuit breaker of the above-mentioned high speed opening type, the distance between the contacts at the time of opening is large, and the breaking speed of the contacts is increased to improve the current limiting performance. Therefore, several suspensions of the spring were tried.

That is, the spring force is normally applied in the direction of closing the contacts, but when the movable conductor begins to open due to the electromagnetic repulsive force generated by the short-circuit current at the time of a short circuit, as the opening progresses, the movable conductor moves in the contact pressure direction. When the rotational moment force biased to or decreases one step beyond the dead center, the moment direction changes in the direction in which the contact opens and the movable conductor rotates. The main part of the example is shown in FIGS. Both are as shown in Fig. 5 and Fig. 7.
When the contacts are closed, the length l of the force F of the springs 1,1 'causes the contact M = F in the direction in which the contacts 3,4 and 3', 4 'are closed.
-The moment force of 1 acts on the movable conductors 2, 2'with the axes 6, 6'as the center. The short circuit current i,
If i ′ respectively flows, the magnitude of the electromagnetic repulsive force acting on the movable conductors 2, 2 ′ and 5, 5 ′ by the short circuit current is
When the moment force due to 1,1 'becomes larger than M, the contact point
3,4 and 3 ', 4' start to open.

As the contact 3,4 or 3 ', 4' separation distance increases, the direction of the force F of the spring 1,1 'gradually changes, and the length l of the armpit decreases, so the moment force M decreases. .
When the dead point is exceeded, the force F generated by the springs 1 and 1'generates a moment force in the direction to open the contact point, as shown in FIGS. 6 and 8, which is extremely fast in combination with the electromagnetic repulsion force. It is possible to open the contacts largely.

However, the methods according to FIGS. 5 and 7 have advantages and disadvantages in structure as follows. That is,
In the method according to FIG. 5, the direction of the coil axis of the spring 1 and the direction of the rotation axis 6 of the movable conductor 2 are orthogonal to each other, and the spring force needs to be large in order to obtain the necessary contact pressure. Due to the expansion and contraction of the spring, the size and length of the spring are limited to a relatively large size, and the size of IB1 in FIG. 5 must be correspondingly large, and the space occupied by this portion cannot be reduced. In addition, the shape of the supporting portion of the spring 1 by the fulcrum 8 has a restriction such that a special device is required as described in Japanese Utility Model Application No. 62-116428 in order to make the operation smooth. It was

On the other hand, in the method shown in FIG. 7, the direction of the coil axis of the coil portion of the spring 1'is parallel to the rotation axis 6'of the movable conductor 2 ', so that the space 1B2 in which the spring is arranged is about the coil diameter of the spring. Although it can be made much smaller than that of the method shown in FIG. 5, the contact between the shaft 7'and the arm portion of the spring 1'is accompanied by sliding, so that the friction is large and the movable conductor 2'does not rotate smoothly. Occurs.

Further, in any of the methods, shafts 7, 7 ', etc. are required in the portions where the spring force is applied to the movable conductors 2, 2', and the method shown in FIG. 7 also requires an additional shaft 9 for supporting the spring 1 '. Therefore, the number of parts was large and the assembly was complicated. In addition, a separate means has to be provided for displacement of the movable conductor, which will be described later.

[Purpose of device]

In view of the above-mentioned problems of the conventional example, the present invention proposes that the movable conductor is instantly fixed without waiting for the contact opening operation on the opening / closing mechanism side by the electromagnetic repulsive force acting between the movable and fixed conductors due to the short-circuit current. In the circuit breaker of the type that opens to the contact and limits the short-circuit current at high speed, the method of suspending the contact pressure spring on the movable conductor is the minimum number of parts, easy to assemble, low cost,
It is also intended to provide a means that can be realized in a space-saving manner so that the size can be reduced.

[Means and actions]

For the above-mentioned purpose, in the present invention, a torsion spring having a coil portion between the arm portions is used as a contact spring of the movable conductor pivotally supported by the crossbar, and the direction of the coil axis of the coil portion is rotated. The torsion spring is arranged parallel to the axis, and the torsion spring has a coil portion between the long arm portion and the short arm portion, and the long arm portion side is the spring support portion of the crossbar and the short arm portion side. Is supported by a spring support portion formed at the end of the movable conductor, and the coil portion is offset from the spring support portion of the crossbar and the spring support portion of the end of the movable conductor toward the rotation axis of the movable conductor. While superimposing on the end, and narrowing the coil part of the spring between the end of the movable conductor and the inner wall of the crossbar, while minimizing the above-mentioned LB dimension,
The spring force is secured so that a sufficient rotation moment can be applied to generate the required contact pressure, the bearing does not have a sliding structure, the movement of the movable conductor is smooth, and no extra parts such as a shaft are required. And, if it is easy to assemble, it is one.

〔Example〕

The configuration of an example of the present invention will be described in detail below with reference to the drawings.

1 to 4 are diagrams of a first embodiment of a movable conductor and a contact spring portion of a circuit breaker according to the present invention, showing a single pole portion. In FIG. 4, 10 is a movable conductor, 15 is an end portion, 16
Is a U-shaped notch with a spring bearing formed at the end.

Reference numeral 32 is a shaft hole, and 11 is a movable contact fixed to the same conductor. Reference numeral 17 is a crossbar, which is a hole-shaped spring bearing portion 19,1
9 ', inner walls 18, 18', and shaft holes 31, 31 '. Reference numeral 20 is a spring, which is a double torsion type in this example, and is 21,21 '.
Is a long arm part, 22,22 'is a short arm part, 23,23' is a coil part, 25 is a connecting part in which the short arm part side is bent, 2
Reference numerals 4 and 24 'are support portions in which the long arm portion side is bent. 14 is an axis.

The suspension structure of the movable conductor and the contact pressure spring according to the present invention can be obtained by combining the above components as shown in FIGS.

That is, the movable conductor 10 is rotatably supported by the shaft 14 between the inner side walls 18, 18 ′ of the crossbar 17, and the spring 20 has the bent support parts 24, 24 ′ of the long arm part 21 for the crossbar 17.
The spring bearings 19,19 'of the short arm 22,22'
25 is supported by a spring support portion 16 formed at the end portion 15 of the movable conductor 10, and the coil axial directions of the coil portions 23, 23 'are parallel to the rotary shaft 14 of the movable conductor 10, and the spring support portions 19, 19 are provided. 'And 16
Energize in the direction of expanding the space.

Also, the long arm portion 21 of the spring 20 is on the crossbar 17 side,
Since the short arm portion 22 is supported on the movable conductor side, the spring 20
The coil portion of is relatively biased toward the rotating shaft 14 side of the movable conductor 10 between the spring supporting portions of 19, 19 'and 16, and the inner wall of the crossbar 1
They are respectively sandwiched between 8, 18 'and the end portion 15 of the movable conductor 10. Here, the dimension of the coil portions 23, 23 'in the coil axial direction is
It is slightly smaller than the distance between the end 15 of the movable conductor 10 and the inner wall 18, 18 'of the crossbar in the direction of the rotation axis
The coil portions 23, 23 'are movable in a substantially arcuate shape when the movable conductor 10 is rotated and the space between the end portion 15 and the inner side walls 18, 18' is viewed from the directions shown in FIGS. Has become.

Further, the crossbar 17 is mechanically connected to a mechanism unit 40 including a manual opening / closing or an overload automatic trip mechanism, and is configured to rotate together with the movable conductor about the crossbar shaft 33 as necessary. Since they are not necessary for the explanation of the present invention, they are shown in a simplified manner.

The operation of the contact pressure spring and the movable conductor configured as described above will be described below.

FIG. 1 is a diagram showing a normal state in which a short circuit does not occur on the load side of the circuit breaker. The spring bearing portion 16 of the movable conductor 10 is supported by the spring 20 against the spring bearing portion 19 of the crossbar 17. The force of F in the direction of the imaginary line connecting the parts 19 and 16 causes the spring support part 16 to move.
Since the movable conductor 10 is pushed in the direction away from 19, the movable conductor 10 tries to rotate about the shaft 14 with a moment of M = F · l, and applies contact pressure between the contacts 11 and 12. In order to obtain the required contact pressure, the force of F determined from the above formula is required, but in the present invention, the spring is a torsion spring,
The coil portion 23 is arranged at a position biased toward the shaft 14 from between the spring bearing portions 19 and 16 by the action of the long arm portion 21 and the short arm portion 22, and is movable in the coil axial direction of the coil portion 23. Since the conductors 10 are parallel to each other in the rotational axis direction, the coil diameter and length of the coil portion 23 for generating the necessary force F are
The wire diameter can be arbitrarily set irrespective of the dimension 1B between the spring support portions 19 and 16, the degree of freedom in spring design is increased, and a large force F can be generated even if the 1B dimension is small. Theoretically, it is possible to realize a spring that can generate the necessary force F even if there is almost no 1B dimension.

At this time, as described in the above description of the structure, the long arm portion 21 is on the spring bearing portion 19 side of the crossbar 17, and the short arm portion 22 is on the spring bearing portion 16 side formed on the end portion 15 of the movable conductor 10. Since the coil portions 23, 23 'of the spring 20 are relatively biased toward the shaft 14 side from between the spring bearing portions 19, 16, the other side portions of the movable conductor 10 of the crossbar inner wall 18, 18' are supported. The movable conductor 10 is held at a substantially central position between the inner side walls 18, 18 ′ of the crossbar 17 because the movable conductor 10 is held between the end portions 15.

Moreover, the movable conductor 10 is constantly urged by the spring in the direction A of FIG. 2, and the shaft hole 32 having a length corresponding to the plate thickness t of the movable conductor is A.
Since it is pressed against the shaft 14 in the direction of the
When viewed from the direction in FIG. 2, 10 is also prevented from tilting with respect to the shaft 14, and the movable conductor 10 and contact 11 are accurately positioned with respect to the crossbar 17 without taking any other special means. Determined.

In the state of FIG. 1, a very large short-circuit current i flows through the fixed conductor 13 and the movable conductor 10, and when the electromagnetic repulsive force acting between both conductors overcomes the moment caused by the spring 20, the contacts are separated. Get started. The relationship between the rotational moment force M and the distance S between the contacts 11 and 12 of the high speed contact opening type contact device as shown in FIG. 1 is shown in the graph of FIG.
In FIG. 9, the vertical axis represents the rotational moment force M of the movable conductor.
In the + direction, the moment force in the direction that the contacts 11 and 12 close,
The-direction is the moment force in the direction that the contacts 11 and 12 open, the horizontal axis is the position where the contacts 11 and 12 are in contact with the distance S between the contacts 11 and 12, is the dead point, is the contact 11 and 12 up to the specified distance. The open position is shown. In the figure, A is the characteristic of the moment of the device according to the present invention, and B is the characteristic of the moment when the high speed opening is not performed by the spring reversal. As shown in Fig. B, in the non-high-speed contact type, the moment force in the direction of closing the contact increases as the contact opens, so the speed of contact separation is slow even if electromagnetic repulsion occurs between conductors. The separation distance between contacts at the same current value becomes small, but in the case of the high speed opening type by spring reversal like the device of the present invention, if the contacts are separated as shown in FIG. The rotation moment decreases as it goes, and when the dead point is exceeded, the moment acts in the direction that the contacts open in reverse, and at the same current value, the contacts open faster and larger than those of the characteristics of B, and the contacts open. It is shown that the arc resistance generated at is increased and the current limiting effect is large.

Due to the above characteristics, when a very large short-circuit current i flows between the fixed conductor 13 and the movable conductor 10, the movable conductor 10 instantly contacts the predetermined stopper 30 as shown in FIG.
2 Rotates in the opening direction, and a small arc that is generated between the contacts at that time and is limited is easily extinguished by an arc extinguishing device (not shown), and it is possible to interrupt a large short circuit current even with a small circuit breaker Becomes

Even in the state of FIG. 3, the spring 20 according to the present invention
Since the long arm portion 21 is supported on the spring bearing portion 19 side of the crossbar 17 and the short arm portion 16 is supported on the spring bearing portion 16 side of the movable conductor 10, it is possible to use a torsion spring. The coil portion 23 does not extend to the left of the drawing from the spring bearing portion 19, the space is minimized, and the end portion 15 of the movable conductor is still sandwiched between the coil portions 23 and 23 '. When the movable conductor 10 is reset from the state shown in FIG. 3 to the state shown in FIG. 1, the coil portions 23 and 23 'of the spring 20 collide with the movable conductor end portion 15, and the coupling portion 25 and the bearing portion 16 are disengaged. It is possible to return to the state of FIG. 1 very smoothly without any trouble.

When shifting from the state of FIG. 1 to the state of FIG. 3 or when resetting from the state of FIG. 3 to the state of FIG. 1, there is no sliding friction as shown in FIG. 7 and the movement is smooth. And, as shown in FIGS. 5 and 7, the shafts 7, 7 '
There is no need for extra parts such as 9 and 9, and no special device is required for the shape in order to support the spring, unlike the portion 8 in FIG.

10 and 11 are views of another embodiment, FIG. 10 shows an example in which the spring has a single torsion, and FIG. 11 shows an example in which the spring bearing relationship is reversed from that in FIG. In each case, the spring is a torsion spring having a crossbar, a spring, a movable conductor, and a rotating shaft of the movable conductor, and the spring is a torsion spring having a coil portion between a long arm portion and a short arm portion. The direction of the coil axis is parallel to the axis of rotation of the movable conductor, the long arm is supported on the crossbar side and the short arm is supported on the movable conductor side, and the coil is relatively movable between the bearings. It does not change to a structure in which the conductor is biased toward the rotation axis and is positioned so as to be sandwiched between the inner wall of the crossbar and the end of the movable conductor.

〔effect〕

As described above, according to the present invention, the suspension structure of the contact pressure spring between the crossbar and the movable conductor of the high-speed contact opening circuit breaker using electromagnetic repulsion can be made extremely small, and the minimum number of parts is required. Assembling can be easily configured at low cost, and the positional relationship between the crossbar and the contact can be accurately determined without using a separate means.

[Brief description of drawings]

FIG. 1 ... Diagram of first embodiment of suspension structure of contact spring of circuit breaker according to the present invention FIG. 2 ... Same as above plan view FIG. 3 ... Diagram in which movable conductor is opened by electromagnetic repulsive force due to short-circuit current Fig. 4 ... Exploded perspective view of the first embodiment Fig. 5, 6 ... Explanatory view of conventional suspension structure of contact pressure spring Fig. 7, Fig. 8 〃 Fig. 9 ... Contact pressure spring suspension structure of the present invention Fig. 10 and Fig. 11 Fig. 10 and Fig. 11 …… Fig. 10 of another embodiment according to the present invention 10 …… Movable conductor, 11 …… Movable contact 14 …… Shaft, 15 …… End part 16, 19 …… Spring support 17 …… Cross bar, 18,18 ′ …… Inner wall 20 …… Spring, 21 …… Long arm 22 …… Short arm, 23 …… Coil

Front page continued (72) Inventor Masazumi Hioka 3-1-2, Oshu, Minami-ku, Hiroshima-shi, Hiroshima Within Pearl Industrial Co., Ltd. (72) Tetsuo Furumoto 3-1-1, Oshu, Minami-ku, Hiroshima-shi, Hiroshima No.42 Examiner at Tempar Industries Co., Ltd. Shinichi Nakagawa (56) References

Claims (3)

[Scope of utility model registration request] 1. A movable conductor having a contact, and a crossbar rotatably pivoting the movable conductor between inner side walls and connected to an opening / closing mechanism portion, and a spring bearing portion and a cross at the end portion of the movable conductor. Between the bar bearings, the movable conductor is normally urged in the direction to close the contacts, and in the case of a short circuit, the electromagnetic conductor repulsive force forces the movable conductor to open, causing the contacts to move in the direction to close. A circuit breaker having a contact structure of electromagnetic repulsion high-speed opening type in which a spring that urges the movable conductor in the direction in which the mover opens when the moment force on the conductor decreases or exceeds the dead center is suspended. In, the spring is a torsion spring having a coil portion between the arm portions, the coil axis direction of the coil portion is arranged parallel to the rotation axis of the movable conductor, and the spring has a coil portion between the long arm portion and the short arm portion. A spring,
The long arm side is supported between the spring support parts of the crossbar, the short arm side is supported by the spring support part formed at the end of the movable conductor, and the coil part is supported by the spring support part of the crossbar and the movable conductor. Between the spring support portions of the movable conductor so that the end portion of the movable conductor around the spring support portion and the coil portion are superposed relative to the rotation axis of the movable conductor, and between the movable conductor end portion and the inner wall of the crossbar. The circuit breaker is characterized in that the coil portion is disposed at a position sandwiched with an appropriate gap. 2. The circuit breaker according to claim (1), characterized in that the spring is a single torsion spring. 3. The circuit breaker according to claim (1), characterized in that the spring is a double torsion spring.