JPS645414B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to circuits and disconnectors.
Note that the term "circuit breaker" or "breaker" used in the present invention refers to a device that generates an arc within a container, usually a small container.

FIGS. 1 to 3 are cross-sectional views of conventional circuits and disconnectors, each showing different operating states.

1 is a cover, 2 is a base, and the cover 1 and the base 2 constitute a container 3. 4 is a fixed contact, which has a fixed contact 6 at one end of its fixed conductor 5;
The other end is a terminal portion to be connected to an external conductor (not shown). A movable contact 7 has a movable contact 9 at one end of a movable conductor 8 facing the fixed contact 6. 10 is a movable contact device, and 11 is a movable arm, which is fixed to a crossbar 12 and configured to open and close each pole at the same time. 13 is an arc extinguishing chamber in which an arc extinguishing plate 14 is held by a side plate 15. Reference numeral 16 denotes a toggle link mechanism, which is composed of an upper link 17 and a lower link 18. Top link 17
One end is attached to the cradle 19, and the other end is attached to the lower link 1.
8 by shafts 20 and 21, respectively. The other end of the lower link 18 is connected to the movable arm 11 of the movable contact device 10. 2
Reference numeral 2 denotes a tilting operation handle, and 23 an operating spring, which is stretched between the shaft 21 of the toggle link mechanism 16 and the operation handle 22. 24 and 25 are thermal and electromagnetic tripping mechanisms, respectively, and when activated, bimetal 26 and movable iron core 2 are activated.
7 rotates the trip bar 28 counterclockwise. Reference numeral 29 is a latch whose one end is locked to the trip bar 28 and the other end is locked to the cradle 19.

When the operating handle 22 is tilted to the closing position with the cradle 19 locked to the latch 29, the toggle link mechanism 16 is extended, the shaft 21 is locked to the cradle 19, and the movable contact 9 is joined to the fixed contact 6. This state is shown in FIG. Then, when the operating handle 22 is tilted to the open position, the toggle link mechanism 16 is bent to separate the movable contact 9 from the fixed contact 6, and the movable arm 11 is locked to the cradle shaft 30. This state is shown in FIG. Furthermore, when an overcurrent flows through the circuit in the closed circuit state shown in FIG. The cradle 19 rotates clockwise around the center and is locked to the stopper shaft 31. The connection point between the cradle 19 and the upper link 17 is the operating spring 23
To cross the line of action, the toggle link mechanism 16 is bent by the spring force of the operating spring 23, and each pole is interlocked by the cross bar 12 to perform automatic shearing.
This state is shown in FIG.

Next, the behavior of the arc that occurs when the circuit or breaker interrupts the current flow will be explained.

Now, when the movable contact 9 and the fixed contact 6 are in contact, the power is transferred from the power supply side to the fixed conductor 5, the fixed contact 6, the movable contact 9, and the movable conductor 8.
It is supplied to the load side via sequentially. In this state, when a large current such as a short circuit current flows through this circuit, the movable contact 9 is separated from the fixed contact 6 as described above. At this time, an arc 32 is generated between the fixed and movable contacts 6 and 9, and an arc voltage is generated between the fixed and movable contacts 6 and 9. This arc voltage increases as the separation distance of the movable contact 9 from the fixed contact 6 increases, and at the same time, the arc 32 is attracted and expanded in the direction of the arc extinguishing plate 14 by magnetic force. , further increases. In this way, the arc current reaches a current zero point, the arc is extinguished, and the shearing is completed. However, this huge amount of arc energy injected eventually becomes thermal energy and completely escapes from the container, but it temporarily increases the temperature of the gas inside the container, which eventually leads to This will cause the gas pressure to rise rapidly. This could lead to deterioration of the insulation inside the circuit or disconnector, an increase in the amount of sparks emitted to the outside of the circuit or disconnector, which could lead to power short-circuit accidents or damage to the circuit or disconnector itself.

This invention was made in view of the above circumstances,
A vertical surface part is formed at the tip of the arc travel path in the electrical contact having an arc travel path formed therein, and this is configured to face in a specific area relationship with an opposing wall surface part formed at the rear end of the arc extinguishing plate. To provide a circuit breaker that can quickly commutate an arc generated between contacts to a desired position, improve breakability, suppress internal pressure, and suppress wear and tear of contacts. It is an object.

An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 4 and 5 show the configuration of essential parts in an embodiment of the circuit breaker of the present invention. In the figure, 101 is one of a pair of electric contacts, for example a movable contact, and includes a movable conductor 102 and a movable contact 103 fixed to the tip of the movable conductor 102 by brazing or caulking means.
and has. A pressure reflector 104 covers the movable conductor 102 around the movable contact 103, and is made of a high-resistance material having a higher resistivity than the movable conductor 102.

The high-resistance material constituting the pressure reflector 104 includes organic or inorganic insulators, or high-resistance materials such as nickel, iron, copper-nickel, copper-manganese, copper-manganin, iron-carbon, iron-nickel, and iron-chromium. The pressure reflector 104 can be formed by directly covering the required portions of the movable conductor 102 using the above material using plasma jet spraying, or by gluing or caulking a molded material using the above material onto the movable conductor. Therefore, it is easily formed. According to the above-mentioned covering means, it is easy to manufacture and inexpensive, and the increase in weight on the movable contact 101 side is suppressed, so the moment of inertia is reduced, the opening speed is increased, and the arc voltage can be increased. There is.

Reference numeral 105 denotes an arc running path formed in the movable contact 101, which extends from the movable contact 103 in the arc moving direction (direction of arrow a). This arc running path 105 has higher conductivity than the pressure reflector 104, and here, the pressure reflector 10
4 is formed with a notch 104a and a movable conductor portion is exposed there. The above arc running path 10
A surface portion 105a substantially perpendicular to the arc running road surface is formed at the tip in the arc movement direction at 5.
Among the plurality of arc extinguishing plates 106 to 110 (FIG. 6), the arc extinguishing plate 106 corresponding to the movable contact 101 in the open position has its rear end facing the vertical surface portion 105a of the arc traveling path 105. The opposite wall surface portion 106a is formed by bending the opposite wall surface portion 106a. The area of this opposing wall surface portion 106a is set to be larger than the area of the vertical surface portion 105a. In other words, when the area of the vertical surface portion 105a is S ₁ and the area of the opposing wall portion 106a is S ₂ , the relationship is S ₁ ≦S ₂ . On the other hand, as shown in FIG.
1 also has a fixed conductor 112 and a fixed contact 113, and a pressure reflector 114 and an arc traveling path 11 similar to those described above.
5 is provided, and the area relationship between the vertical surface portion 115a at the tip of the arc traveling path 115 and the opposing wall surface portion 110a at the rear end of the arc extinguishing plate 110 is also set in the same manner as on the movable contact 101 side described above. There is.

Next, the operation of the above configuration will be explained with reference to FIG.

When the movable contact 101 and the fixed contact 111 are separated due to the occurrence of a fault current or the like, an arc 32 is generated between the movable and fixed contacts 103 and 113. The arc 32 is then subjected to the following action. Since the pressure reflectors 104, 114 of the movable and fixed contacts 101, 111 have high resistance, the arc 3
The expansion of the legs of No. 2 is suppressed, and the positive column part is affected by the pressure reflectors 104 and 11 due to the explosive force of the arc itself.
4 by increasing the back pressure on the surface of the arc-extinguishing plates 106-110, and is further attracted and driven toward the arc-extinguishing plates 106-110 by the variable distortion magnetic fields of the arc-extinguishing plates 106-110. These actions cause the arc voltage to rise rapidly.

On the other hand, since the pressure reflectors 104 and 114 are configured such that the opposite side to the arrangement side of the arc extinguishing plates 106 to 110 is closed with respect to each contact 103 and 113, even if the arc voltage increases, the pressure reflector It cannot move in the direction in which the arcs 104 and 114 are closed, but moves along the arc travel paths 105 and 115. Therefore, the legs of the arc 32 are the contacts 103,1
13 and is commutated to the most vertical surface portions 105a, 115a of the arc travel paths 105, 115.
Since the arc 32 originally has the property of blowing out in a direction perpendicular to the plane composing its legs, the arc 32 at the time of commutation assumes a posture as shown in FIG.
06, 110 each opposing wall surface part 106a, 110a
After that, it is divided by each of the arc extinguishing plates 106 to 110. That is, since the arc 32 is completely cooled by contacting the arc extinguishing plates 106 to 110, an increase in internal pressure due to the generation of the arc 32 is suppressed. Furthermore, since the arc 32 is separated from the contacts 103 and 113 at the beginning of the current interruption, unnecessary wear and tear of the contacts 103 and 113 is suppressed. In particular, the area of each opposing wall surface portion 106a, 110a of the arc extinguishing plate 106, 110 is calculated as the area of each vertical surface portion 105a, 110 of the arc running path 105, 115
Since it is set to 5a or more, the vertical surface portion 10
The legs of the arc 32 located at 5a and 115a are easily transferred to the opposing wall portions 106a and 116a, so that the above effects can be exerted more reliably.

In addition, in the above embodiment, the configuration of the main part of the present invention was explained as an example in which it was applied to both the movable and fixed contacts 101, 111. It's okay.

Furthermore, the vertical surface portions 105a, 115a at the tips of the arc travel paths 105, 115 are constructed from parts of the movable and fixed conductors 102, 112, respectively; , 112 may also be made of a good conductor.

In addition, the movable contact 101 and the fixed contact 11
A similar effect can be achieved by the above structure even if the contactor 1 is configured with a repulsive type contact that opens due to electromagnetic repulsion.

As described above, the present invention forms a vertical surface portion at the tip of the arc travel path in an electric contact having an arc travel path, and correspondingly increases the area of the opposing wall surface portion formed at the rear end of the arc extinguishing plate. By making the area larger than the area of the vertical surface portion, it is possible to provide a circuit breaker that improves insulation properties, suppresses internal pressure, and ensures a long life of the contact.

[Brief explanation of the drawing]

1 to 3 are cross-sectional views of conventional circuit breakers and breakers in different operating states, FIG. 4 is an exploded perspective view of the main parts of the circuit breakers and breakers according to the present invention, and FIG. 5 is the same. FIG. 6, which is a cross-sectional view of the main parts of the circuit breaker and breaker, is an explanatory diagram of the operation of the circuit breaker and breaker of the present invention. 32...Arc, 101,111...Electric contact, 102,112...Conductor, 103,113...
... Contact, 104, 114 ... Pressure reflector, 10
5,115...Arc running path, 105a, 115
a... Vertical surface part, 106-110... Arc-extinguishing plate, 1
06a, 110a...Opposing wall surface part, _S1 ...Area of vertical surface part, _S2 ...Area of opposing wall surface part. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. At least one pair of electrical contacts that are constructed of a conductor and contacts fixed thereto and that open and close, and a plurality of electrical contacts that are made of a good magnetic conductor and that cool and eliminate arcs generated between the contacts. an arc-extinguishing plate, a pressure reflector made of a high-resistance material having a higher resistivity than the conductor on at least one of the paired electric contacts and covering the contact area of the conductor; and a pressure reflector surrounded by the pressure reflector. an arc traveling path extending from the contact point in the direction of arc movement and having higher conductivity than the pressure reflector, and forming a vertical surface portion substantially perpendicular to the surface of the arc traveling path at the tip of the arc traveling path in the direction of arc movement; Then, at the open position of the electric contact having the arc running path, an opposing wall portion located at the rear end in the arc movement direction and facing the vertical surface portion is formed on the arc extinguishing plate corresponding to the opening position of the electric contact having the arc travel path, and A circuit breaker characterized in that its area is set to be greater than the area of the vertical surface portion. 2. The circuit breaker or breaker according to claim 1, wherein the pair of electric contacts operate to open each other by electromagnetic repulsion.