JPH0142288Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to a circuit breaker that prevents deformation of a movable contactor.

[Prior Art] Hereinafter, an explanation will be given using an example of an electric leakage or a disconnection. FIG. 1 shows a general circuit configuration for leakage and disconnection. In the figure, 1a and 1b are power supply terminals, 2
a, 2b are opening and closing devices, 3 is opening and closing operation device, 4a,
4b is an overcurrent detection device, 5 is a zero-phase current transformer, 6a,
6b is a load terminal, 7 is an amplifier, 8 is an electromagnetic device,
9 is a control circuit switch, 10 is a test switch,
Reference numeral 11 denotes a resistor, which constitutes a main circuit extending from power supply terminals 1a and 1b to load terminals 6a and 6b via switching devices 2a and 2b and overcurrent detection devices 4a and 4b.

Next, the operation will be explained. First, under normal conditions, by tilting the handle (not shown) of the opening/closing device 3 to one side, the opening/closing devices 2a and 2b are turned ON in conjunction with this, and the above-mentioned main circuit is formed. Then, the load terminals 6a and 6b are energized. When the power is turned off, the switchgear 2a, by tilting the handle to the other side.
2b is turned off, and load terminals 6a and 6b are disconnected from power supply terminals 1a and 1b.

If an overcurrent flows in the main circuit while the switchgear 2a, 2b is ON, the overcurrent detection device 4a,
4b detects this overcurrent and operates the switching device 3 to turn off the switching devices 2a and 2b.

On the other hand, if a current leakage occurs on the load side while the switchgear 2a, 2b is ON, the current imbalance in the main circuit is detected by the zero-phase current transformer 5, and the zero-phase current transformer 5 The output of the secondary side of is amplified by the amplifier 7, and the electromagnet device 8 is operated by the output. By operating the electromagnet device 8, the opening/closing devices 2a and 2b are turned off via the opening/closing operation device 3.
becomes.

In addition, when testing whether or not the current disconnection operation is reliably performed due to earth leakage, the zero-phase current transformer 5 is turned on by turning on the test switch 10.
Since a minute current flows through the primary side, the situation is equivalent to a current leakage occurring on the load side, and the switchgear 2a, 2b is closed according to the same principle as described above.
OFF operation can be confirmed.

Note that in the above configuration, the control circuit switch 9
is linked to ON and OFF of switchgear 2a and 2b.
This turns ON and OFF, which causes the switchgear 2
When a and 2b are off, the amplifier 7 is disconnected from the main circuit.

FIG. 2 is a partial cross-sectional view showing the structure of a conventional leakage circuit. In the figure, the base 21 includes a fixed contact 25 having a fixed contact 26, and a fixed contact 25 having a fixed contact 26.
A movable contact 2 having a movable contact 29 facing 6
8 are arranged, and these constitute the above-mentioned opening/closing devices 2a, 2b. Although FIG. 2 shows only one set of the fixed contactor 25 and the movable contactor 28, in reality, another set is arranged in parallel. The movable contact 28 includes a movable contact 29
At the time of fixing, the auxiliary movable contact 109 is fixed at the same time, and on the other hand, the auxiliary fixed contact 110 is fixed to the base 21. Auxiliary movable contact 109
The auxiliary movable contact 111 is the auxiliary fixed contact 11
Auxiliary fixed contacts 112 are attached to each of the terminals 0, and these constitute the contacts of the control circuit switch 9 described above. 42 is a handle, and 56 is a presser plate that moves up and down in conjunction with the handle 42. By tilting the handle 42 to the left in the figure, the presser plate 56
moves downward and presses the movable contact 28 to bring the movable contact 29 into contact with the fixed contact 26. At this time, the auxiliary movable contact 111 is also connected to the auxiliary fixed contact 1.
Contact 12.

However, in the conventional device as described above, when an overcurrent flows, the movable contact 2
When the contactor 8 returns, if the contactor 28 is largely displaced upward due to inertia, the bent portion 2 of the contactor 28 may be damaged.
Deformation occurs near 8a, which not only reduces the durability life, but also because both contacts 26 and 29 and both auxiliary contacts 111 and 112 are close to each other,
There is a drawback that the arc generated between the two contacts 26 and 29 has an adverse effect on the auxiliary contacts 111 and 112, such as burning out.

[Summary of the idea]

This idea was made to improve the above-mentioned drawbacks. It prevents deformation and breakage of the movable contact that repeatedly swings when opening and closing the contacts, and prevents the arc generated between the two contacts from causing burnout or other damage to the auxiliary contacts. The purpose is to provide circuit breakers and disconnectors that do not cause any adverse effects.

[Embodiments of the invention] Examples of the invention will be described below with reference to the drawings. FIG. 3 is a sectional view of an earth leakage switch and disconnector which is an embodiment of this invention. In addition, in the following explanation,
The same parts as in FIGS. 1 and 2 are given the same reference numerals. In FIG. 3, 21 is a base molded from synthetic resin, 1 is a power terminal equipped on this base 21, a tightening screw 23 and a box-shaped terminal fitting 24 into which this tightening screw 23 is screwed. One end of a fixed contact 25 of the main circuit is inserted into the terminal fitting 24 and electrically connected. Fixed contact 25
A fixed contact 26 is fixed to the other end. 27
is an insertion plate for fixing the fixed contact 25.

28 is a movable contact, and a movable contact 29 of the main circuit is fixed to the distal end facing the fixed contact 26 of the main circuit, and the base end thereof is a bimetal 3 to be described later.
The movable contact 28 is fixed to the support plate 31 together with the movable contact 28, and the approximately middle portion of the movable contact 28 is bent to the same radius as the arc portion of the support plate 31, and is formed into an arc shape so as to make surface contact with the arc portion. . Although only one set of the fixed contact 25 and the movable contact 28 is shown in FIG. 3, in reality, another set is arranged in parallel. The switchgear 2 in FIG.
a and 2b are configured.

32 is a mounting screw for fixing the support plate 31 to the base 21; the base end of the bimetal 30 is fixed to the support plate 31 as described above, and the distal end is attached to the tripping rod 3.
It is designed to come into contact with the tip of an adjustment screw 34 attached to 3. This bimetal 30 constitutes overcurrent detection devices 4a and 4b in FIG.

35 is a flexible copper stranded wire with an insulation coating arranged so as to pass through the center hole 5a of the zero-phase current transformer 5;
One end thereof is fixed to approximately the center of the bimetal 30, and the other end is fixed to the terminal plate 36.

6 is a load terminal installed on the opposite side of the base 21 from the power supply terminal 1, and includes a tightening screw 38 and a box-shaped terminal fitting 37.
The terminal metal fitting 37 includes the terminal plate 3 described above.
6 is inserted and electrically connected. 39
is an insertion plate for fixing the terminal plate 36.

A case 57 houses the amplifier 7 therein, and is mounted in a recess 21 a formed on the bottom surface of the base 21 . Reference numeral 58 denotes a switch base, inside of which are a control circuit switch blade 60 and a test switch 10 that constitute the control circuit switch 9 in FIG.
a test switch blade (not shown),
A control circuit switch blade 60 extends from the switch base 58, and has an auxiliary movable contact 63 fixed to its tip.

On the other hand, near the part where the support plate 31 is fixed to the base 21, there is a vertical piece 31b and a stopper part 3 connected thereto.
1a, and this stopper portion 31a is for stopping the movable contact 28 returning to a predetermined position. The stopper portion 31a is provided with the above-mentioned auxiliary movable contact 63.
An auxiliary fixed contact 64 facing the is fixed.

Reference numeral 56 denotes a holding plate molded from synthetic resin. In the state shown in FIG. The contacts 26 and 2 are in an open state, and the contacts 26 and 2 are in an open state.
It has been open for 9 hours. When the handle 42 is tilted to the left, the presser plate 56 is lowered in conjunction with this,
As shown in FIG. 4, the movable contact 28 is pressed to bring the movable contact 29 into contact with the fixed contact 26. At this time, since the control circuit switch blade 60 curves downward due to its own elasticity, the auxiliary movable contact 63
also contacts the auxiliary fixed contact 64.

The connection relationships among the parts shown in FIGS. 3 and 4 are as shown in FIG. 1.

In the state shown in Fig. 4 above, if an overcurrent flows to the load side, if a leakage occurs to the load side, or if the test switch 10 is pressed, the movable contact 28 returns to its original position and becomes movable. The contact 29 is separated from the fixed contact 26, and the electrical circuit is broken.

When the movable contact 28 returns, the contact 28
tends to deform upward due to its inertia, but in the configuration shown in FIG. 3, the stopper portion 31a is provided on the support plate 31, so the movable contact 28 is deformed upward by the stopper portion 31a when returning. The movement of people is regulated. Therefore, deformation of the movable contactor 28 near the bent portion 28a due to inertia can be prevented.

Further, as in the above embodiment, the control circuit switch blade 60 is provided separately from the movable contact 28,
In addition, by providing the auxiliary movable contact 63 and the auxiliary fixed contact 64 at a position away from both contacts 26 and 29 of the main circuit, the arc generated between these two contacts 26 and 29 will not cause burnout or other damage to the auxiliary contacts 63 and 64. It is possible to prevent any adverse effects from occurring.

[Effects of the invention] As explained above, according to this invention, the distal end has a movable contact corresponding to the fixed contact of the main circuit, and the proximal end is swingable on the support plate fixed to the base. a movable contact supported by a movable contact; and a stopper portion that is formed integrally with the support plate and engages with a base end portion of the movable contact that returns to the movable contact to stop the movable contact at a predetermined position; Since this stopper part is provided with an auxiliary fixed contact corresponding to the auxiliary movable contact of the auxiliary circuit that is separated from both contacts of the main circuit, it is possible to prevent deformation and breakage of the movable contact that repeatedly swings when opening and closing the contact. In addition, since both contacts of the main circuit are separated from both contacts of the auxiliary circuit, the arc generated at both the contacts of the main circuit does not have an adverse effect such as burning out on both contacts of the auxiliary circuit.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the general circuit configuration of an earth leakage circuit breaker, Figure 2 is a partial sectional view showing the structure of a conventional earth leakage circuit breaker, and Figure 3 is a circuit diagram of this invention. A cross-sectional view showing an embodiment of the invention in the OFF state, No. 4
The figure is a cross-sectional view in the ON state. 21... Base, 28... Movable contact, 29...
Movable contact, 31...Support plate, 31a...Stopper portion, 63...Auxiliary movable contact, 64...Auxiliary fixed contact. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] A movable contact having a movable contact corresponding to the fixed contact of the main circuit at the distal end and swingably supported at the base end by a support plate fixed to the base, and a movable contact formed integrally with the support plate. a stopper part that engages with the base end of the movable contact that is returning to its original position and stops the movable contact at a predetermined position; A circuit breaker characterized by having a fixed contact.