JP4407651B2 - Circuit breaker movable contact device - Google Patents

Description

  The present invention relates to a movable contact device of a circuit breaker such as a circuit breaker for wiring or an earth leakage breaker.

  The circuit breaker switching life includes a mechanical switching life and an electrical switching life, and the mechanical switching life is mainly determined by wear and damage to the mechanical part. Fatigue disconnection of a component (hereinafter referred to as a shunt) that makes a thin plate flexible and electrically connects is a major factor that limits the switching life.

  As a measure to eliminate the above factors, there is known an energization mechanism in which the movable contact and the mover receiver are brought into sliding contact and the contact pressure between the movable contact and the mover receiver is increased by a compression spring disposed outside the mover receiver. The movable contact device composed of the movable contact and the movable receiver does not use a shunt and is generally called a “shuntless energization mechanism”. (For example, see Patent Document 1)

Japanese Patent No. 3396877 (FIG. 1)

The conventional movable contact device of the circuit breaker is configured as described above, and the thickness dimension of the movable contact tends to fluctuate, and the contact resistance between the movable contact and the movable receiver becomes unstable. was there.
Moreover, since the structure is such that the compression spring is pressed from the outside of the mover receiver, there is also a problem that the volume of the portion required for this energization mechanism is increased.

  Furthermore, the pressing structure by the compression spring causes the contact surfaces facing each other of the movable element receiver to bend while making contact with the movable contact element, which easily causes point contact due to the bending, and conversely increases contact resistance. There was a fear.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain a movable contact device for a circuit breaker that is small and has stable contact resistance.

  A movable contact device for a circuit breaker according to the present invention is connected to an opening / closing mechanism and has a cross bar supported to rotate in conjunction with the opening / closing mechanism, and a rotation hole. And a pair of connecting conductors having through-holes through which the shafts are opposed to each other, and a movable contact that is pivotally arranged on the crossbar with both ends of the shaft supported by the crossbar. And a mover receiver fixed to a housing in which the opening / closing mechanism is accommodated, and a spring accommodating part disposed on the opposite surface of the contact part of the movable contact opposite to the connection conductor part of the mover receiver. And an oblique coil ring spring sandwiched between the movable contact elements, and the movable contact element is configured to be slid by being pressed by the oblique coil ring springs on the connecting conductor portion of the movable element receiver.

  The present invention can provide a movable contact device for a circuit breaker having a stable contact resistance and a high current-carrying capacity while being a shuntless current-carrying mechanism having an excellent mechanical switching life.

Embodiment 1 FIG.
FIG. 1 is a longitudinal sectional view showing a closed state of a movable contact device for a circuit breaker according to Embodiment 1 of the present invention, and FIG. 2 is a partial sectional top view along line AA in FIG. It also serves as a plan view of the movable contact device. 3 is a cross-sectional bottom view taken along line BB in FIG. 2, FIG. 4 is an external perspective view of the oblique coil ring spring, FIG. 5 is a detailed shape explanatory view of the oblique coil ring spring, and FIG. It is a figure showing the correlation of a displacement and a load.

In the figure, a cover 1 and a base 2 constitute a casing of the circuit breaker 101, and are each formed of a synthetic resin such as a thermoplastic resin.
The base 2 houses an opening / closing mechanism 102, and a handle 3 linked to the opening / closing mechanism 102 protrudes from the handle window hole 1a of the cover 1 to the surface of the cover 1 and is manually operated from the outside. It is possible.
With the position of the handle 3 of the circuit breaker 101 as the center, the right side of FIG. 1 is connected to a power source side electric wire (not shown), and the left side is connected to a load side electric wire.

A fixed contact 4 constituting a connecting portion with a power supply side electric wire is fixed to the base 2 with a screw 5, and a fixed contact 6 fixed to the fixed contact 4 is fixed to one end of a movable contact 8. The electric circuit is turned on and off by contacting and leaving the contact 7.
A rotating hole 8a (shown in FIG. 2) is provided at the other end of the movable contact 8. A shaft 9 passes through the rotating hole 8a, and both ends of the shaft 9 are supported by the crossbar 10. As a result, the movable contact 8 is formed on the cross bar 10 so as to be rotatable, so that the movable contact 7 is brought into contact with and separated from the fixed contact 6 with the shaft 9 as a fulcrum.

The movable contacts 8 are arranged side by side in line symmetry, and are sandwiched between movable member receivers 11. The movable member receivers 11 are fixed to the base 2 by screws 12 and connected to the relay conductors 14 by screws 13.
Further, the relay conductor 14 is connected to a load conductor 15 constituting a connecting portion with a load side electric wire via a heater constituting an overcurrent tripping device (not shown). Therefore, the current path in the closed state is fixed contact 4 → fixed contact 6 → movable contact 7 → movable contact 8 → movable element receiver 11 → relay conductor 14 → heater → load conductor 15.
In the above configuration, the movable contact device 103 is configured by the movable contact 8, the shaft 9, the cross bar 10, the mover receiver 11, and the oblique coil ring spring 17 described later.

  The mover receiver 11 includes a screw female screw (not shown) to which the screw 12 is screwed, a base portion 11a having a mounting hole 11c through which the screw 13 passes, and a base portion 11a that is raised at a right angle, with the tips facing each other. 9 is integrally formed with a pair of connecting conductor portions 11b having through holes 11d through which 9 penetrates.

A spring accommodating portion 8b and a positioning convex portion 8c serving as positioning means are disposed on the opposite surfaces of the contact portions 8d of the movable contactors 8 arranged side by side, which are surfaces facing the mover receiver 11. The slant coil ring spring 17 is housed in the spring housing portion 8b and is sandwiched between the movable contacts 8.
In the above description, the movable contacts 8 are arranged one by one in line symmetry, but a plurality of movable contacts 8 may be arranged in parallel.
In addition, although the positioning convex portion 8 c as positioning means is integrated with the movable contact 8, it may be a cylindrical part separate from the movable contact 8 and may be fitted on the shaft 9.

Next, a method of assembling the movable contact device for a circuit breaker according to Embodiment 1 of the present invention configured as described above will be described.
The diagonal coil ring spring 17 is sandwiched between the movable contacts 8 arranged side by side, and the relative contact of the movable contacts 8 is at least until the dimension C (shown in FIG. 2) between the pair of connecting conductor portions 11b is equal to or less. The movable contact 8 is pressed in the direction in which the facing surface is in contact, and inserted between the pair of connection conductor portions 11b. After that, the through hole 11d and the rotation hole 8a are aligned and the shaft 9 is fitted and inserted, and then the shaft 9 is engaged with the U-shaped groove of the cross bar 10 so that the movable contact 7 and the fixed contact 6 are interposed. By applying a rotational moment to the movable contact 8 by a contact pressure spring (not shown) that forms a contact pressure, a contact pressure between the fixed contact 6 (see FIG. 1) and the movable contact 7 is generated, and the movable contact device of the circuit breaker. Is configured.

  At this time, the contact portion 8d of the movable contact 8 can be kept in surface contact with the connecting conductor portion 11b by the oblique coil ring spring 17, so that the contact resistance is stabilized. In addition, it is not necessary to strictly manage the dimension C of the mover receiver 11, and it is not necessary to bend the connecting conductor portion 11b. Therefore, the connecting conductor portion 11b can be thickened, and the resistance value can be reduced. Energization capability can be increased.

Next, the oblique coil ring spring 17 will be described in detail.
The oblique coil ring spring 17 is formed of, for example, a nickel-plated stainless steel wire, and as shown in FIGS. 4 and 5 (a), a normal coil with the inner diameter portion 17a secured to a predetermined dimension. The two ends of the spring are joined to form a ring shape. Further, as shown in FIG. 5 (b) in which a part of FIG. 5 (a) is enlarged, the direction parallel to the central axis of the coil is the X direction, X The direction perpendicular to the direction (vertical direction on the paper surface of FIG. 5) is the Z direction, an arbitrary point on the coil is A, and the intersection point A with the perpendicular to the central axis of A is seen from the Y direction. Sometimes, the intersection of the perpendicular to the central axis of the position B when traveling half-clockwise from A along the coil, and the central axis of the position C traveling half-clockwise along the coil from A The relationship with the intersection of the perpendicular to the In the case of the spring, whereas there is a b between b and c, in the case of the oblique coil ring spring 17 is obtained by forming so as to position between the outside of the furnace and the wafer.

When the oblique coil ring spring 17 is pressed in the Z direction of the ring, a δ-F diagram (shown in FIG. 6) representing the correlation between the displacement and the load has characteristics different from those of a general coil spring.
In other words, in the case of a general coil spring, the δ-F diagram is linear because it is proportional to the spring constant, but the δ-F diagram of the oblique coil ring spring 17 has an inflection point, and the displacement When the operating range is δ1 to δ2, the pressing force obtained with a general coil spring is in the range of F1 to F3, but the pressing force obtained with the oblique coil ring spring 17 is in the range of F1 to F2, As compared with a typical coil spring, a change in the pressing force when the amount of displacement changes is small and a stable pressing force can be obtained, so that the contact portion 8d of the movable contact 8 makes surface contact with the connecting conductor portion 11b. Can be maintained, and the contact resistance is stabilized.

When the slant coil ring spring 17 is pressed in the Z direction of the ring, each slant coil forming the slant coil ring spring 17 is deformed into an elliptical shape in the case of a general coil ring spring. Thus, the diagonal coil operates so as to fall from FIG. 5 (b) to FIG. 5 (c).
As a result, the slant coils forming the slant coil ring spring 17 are in a state where they are displaced from each other in a slant direction, so that when each coil falls while maintaining the distance between the coils at the center axis of the coil. Each coil generates a tensile load with each other, reducing the diameter of each coil itself, but the elastic member such as stainless steel forming the coil tries to maintain the diameter of each coil due to rigidity. As a result, the distance between the coils of each coil is reduced, and the inner diameter portion 17a is reduced in diameter when viewed as an oblique coil ring spring.
Therefore, in order to prevent this diameter reduction, a positioning convex portion 8c, which is a positioning means for positioning the inner diameter portion 17a, is disposed inside the oblique coil ring spring 17.

  In addition, since the total dimension (equivalent to E + D + E) of the movable contact 8 in a state where the oblique coil ring spring 17 is sandwiched is only slightly larger than the dimension C before being inserted between the connecting conductor portions 11b, it is easy. The movable contact 8 can be pressed in the direction in which the movable contact 8 is brought into close contact with the connection conductor 11b, and insertion between the pair of connection conductors 11b is easy.

Here, the dimension D is slightly reduced as compared with that before insertion between the connecting conductor portions 11b, but this reduced amount is converted into a pressing force of the contact portion 8d to the connecting conductor portion 11b.
In the movable contact device of the circuit breaker according to Embodiment 1 of the present invention configured as described above, the contact portion 8d of the movable contact 8 is connected to the connecting conductor portion 11b by disposing the oblique coil ring spring 17. On the other hand, since there is little change in the pressing force and a stable pressing force can be maintained and the surface contact can be maintained, the contact resistance is stabilized and the movable contact device can be miniaturized.

As described above, when the diagonal coil ring spring 17 is pressed in the Z direction of the ring, the individual diagonal coils forming the diagonal coil ring spring 17 operate so as to fall down. Since sliding occurs on the contact surface between the spring 17 and the movable contact 8, friction also occurs at the same time. The friction on the contact surface between the coil ring spring 17 and the movable contact 8 becomes a factor that makes the pressing force of the oblique coil ring spring 17 unstable.
To cope with this, the slant coil ring spring 17 is plated with nickel having good slidability, or the spring housing portion 8b in which the slant coil ring spring 17 and the movable contact 8 slide is fluorinated, molybdenum compound, or carbon. By applying a lubricant containing at least one of the fine particles or a combination thereof, the friction is reduced, and the effect of stabilizing the spring load can be obtained.

According to the movable contact device of the circuit breaker of the first embodiment configured as described above, the movable contact 8 is pressed against the connecting conductor portion 11b of the mover receiver 11 by the oblique coil ring spring 17 to make surface contact. Since it is configured to be able to keep and slide, the contact resistance is stabilized.
Further, even when the movable contactor 8 repeatedly rotates, the inner diameter portion 17a of the oblique coil ring spring 17 is maintained by the positioning convex portion 8c serving as positioning means, so that the inner diameter portion 17a is reduced in diameter. In addition, a stable pressing force can be maintained and the contact resistance is stabilized.

Embodiment 2. FIG.
In the first embodiment, a circuit breaker having a large energization capacity is assumed, and the movable contacts 8 are arranged side by side. However, the case where a single movable contact 8 that is applied when the rated current is small is used. Note that FIG. 7 is a diagram corresponding to FIG. 3 in the first embodiment, and the others are the same as those in the first embodiment and are omitted.

  In FIG. 6, a spring accommodating portion 8b and a positioning convex portion 8c serving as a positioning means are arranged on the opposite surface of the contact portion 8d of the movable contact 8 facing one of the connection conductor portions 11b of the mover receiver 11. The slanted coil ring spring 17 is sandwiched between the other connecting conductor part 11 b and the movable contactor 8 is pressed by the slanted coil ring spring 17 against the other connecting conductor part 11 b of the mover receiver 11. Are configured to slide.

Other configurations and operations are the same as those in the first embodiment, and the movable contact 8 is pressed against the other connecting conductor portion 11b of the mover receiver 11 by the slant coil ring spring 17 to keep the surface contact and slide. Since it is comprised so that it can do, contact resistance is stabilized.
Even when the movable contactor 8 repeatedly rotates, the inner diameter portion 17a of the oblique coil ring spring 17 is maintained by the positioning convex portion 8c as positioning means, so that the inner diameter portion 17a is not reduced in diameter. , Can keep a stable pressing force, stable contact resistance.

  In both the first and second embodiments, the mover receiver 11 has been described as an integrally formed product. However, the present invention is not limited to this. For example, as shown in Patent Document 1, a pair of divided pieces is used. It goes without saying that the same effect can be obtained even when the mover receiver is applied.

It is a longitudinal cross-sectional view which shows the movable contact apparatus of the circuit breaker in Embodiment 1 of this invention in a closed state. FIG. 2 is a partial cross-sectional top view taken along line AA in FIG. 1. FIG. 3 is a cross-sectional bottom view taken along line BB in FIG. 2. It is an external appearance perspective view of the diagonal coil ring spring in Embodiment 1 of this invention. It is detailed shape explanatory drawing of the diagonal coil ring spring in Embodiment 1 of this invention. It is a figure showing the correlation of the displacement and load of a diagonal coil ring spring in Embodiment 1 of this invention. It is a figure of the FIG. 3 equivalent part of Embodiment 1 in the movable contact apparatus of the circuit breaker in Embodiment 2 of this invention.

Explanation of symbols

1 cover (housing), 2 base (housing), 3 handle, 8 movable contact,
8a Rotating hole, 8b Spring storage part, 8c Positioning convex part (positioning means),
8d contact portion, 9 axes, 10 crossbar, 11 mover receiver, 11b connecting conductor portion, 11d through hole, 17 oblique coil ring spring, 17a inner diameter portion,
DESCRIPTION OF SYMBOLS 101 Circuit breaker, 102 Opening-closing mechanism part, 103 Movable contact apparatus.

Claims (5)

A crossbar connected to the opening / closing mechanism and supported so as to rotate in conjunction with the opening / closing mechanism, and a rotation hole, and a shaft is passed through the rotation hole so that the crossbar has both ends of the shaft. A movable contact that is pivotally arranged in parallel with the crossbar and a pair of connecting conductors that have through-holes through which the shaft passes and that are opposed to each other, and the opening / closing mechanism is housed. A movable element receiver fixed to a housing, and a movable element that is accommodated in a spring accommodating portion disposed on a surface opposite to a contact portion of the movable contact element facing a connection conductor portion of the movable element receiver. A slanted coil ring spring sandwiched between the movable contact and the connecting conductor portion of the armature receiver, wherein the movable contactor is pressed by the slant coil ring spring and slides. A movable contact device for circuit breakers. A crossbar connected to the opening / closing mechanism and supported so as to rotate in conjunction with the opening / closing mechanism, and a rotation hole, and a shaft is passed through the rotation hole so that the crossbar has both ends of the shaft. A movable contact that is pivotably formed on the cross bar and a pair of connecting conductors that have through-holes through which the shaft passes and that are opposed to each other and that stores the opening / closing mechanism. A movable part receiver fixed to the housing, and the other is accommodated in a spring accommodating part disposed on the opposite surface of the contact part of the movable contact element opposite to the connection conductor part of the movable element receiver, and the other An inclined coil ring spring sandwiched between the movable conductor and the other contact conductor portion of the movable element receiver so that the movable contact member is pressed and slid by the oblique coil ring spring. Circuit interruption characterized by being configured Moving contact device. 3. The movable contact device for a circuit breaker according to claim 1, wherein positioning means for positioning an inner diameter portion of the oblique coil ring spring is provided on the movable contact. The movable contact device for a circuit breaker according to any one of claims 1 to 3, wherein the oblique coil ring spring is formed of a stainless steel wire and nickel-plated. The movable contact device for a circuit breaker according to any one of claims 1 to 4, wherein a lubricant is applied to the spring housing portion.

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