JPS5820445B2 - Arc room - Google Patents

Description

[Detailed description of the invention] The present invention relates to an arc extinguishing chamber of a circuit breaker.

In general, in a self-powered arc extinguishing chamber, when the breaking current is large, the pressure inside the arc extinguishing chamber increases, and this increased pressure causes the arc generated between the fixed and movable contacts in the arc extinguishing chamber to be A horizontal spraying method is used that generates an oil flow and sprays it onto the arc to extinguish the arc.However, when the breaking current is small, the pressure generated in the arc extinguishing chamber is small, so in this case It is no longer possible to extinguish the arc using only the self-cutting action of extinguishing the arc using the oil flow generated by gas pressure.

Therefore, in order to compensate for this, a cylinder is provided above the self-powered arc extinguishing chamber, and a piston is placed inside the cylinder, and the piston is pressed by the elasticity of a spring to generate a forced oil flow.When a small current is cut off, this forced oil flow An arc extinguishing chamber has been manufactured that takes into account the action of an external force to extinguish the arc by causing it to act on the arc.

That is, FIG. 1 is a vertical cross-sectional view showing an example of this type of arc extinguishing chamber conventionally manufactured, and 101 is the arc extinguishing chamber main body, inside which is a fixed contact 102 and a contact base 10 for fitting and contacting the same.
3 and a plurality of arc extinguishing plates 104 are installed, and a movable contact 105 advances and retreats within the arc extinguishing chamber main body 101 to contact and close the fixed contact 102 or to separate and open.

A cylinder 106 is provided in the upper part of the arc-extinguishing chamber main body 101 in communication with the cylinder, and a piston 107 and a piston rod 108 are arranged inside the cylinder, and are pushed upward when the movable contact 105 is inserted.

Reference numeral 109 denotes a return spring for returning the piston 107 downward when the movable tangent angle member 105 is released.

When the movable contactor 105 starts to open and separate, the piston 10
7, the piston 107 in the cylinder 106 is pushed down by the restoring elasticity of the return spring 109.
The oil at the bottom of the stationary contact 102 is pressed to generate an oil flow, which flows through the center and periphery of the stationary contact 102 from the axis A and the oil hole B of the contact base 103 to the tip center C of the stationary contact 102 and the stationary The tip peripheral surface of the contactor 102 and the uppermost arc extinguishing plate 10
4 through the gap between the fixed contact 102 and the movable contact 105 that is separating, and both contacts 102.1.
It acts on the arc that occurred during 05 to extinguish the arc.

However, the oil flow is ejected in the axial direction with respect to the arc generated between the surface contacts, and it does not pass through a passage with a special acceleration configuration only by the force of the piston, so the flow velocity is relatively low. Since it is small, its action on the arc is relatively slow, and the speed at which the oil, which has become contaminated and the insulation level has deteriorated at the point where the arc occurs, flows out and moves is extremely slow.

Therefore, although an arc extinguishing chamber equipped with only this forced oil flow source has the ability to cut off normal load currents and small cheek currents, it is difficult to use capacitor circuits, which have extremely severe circuit conditions. It was considered difficult to cut off a small current without re-ignition.

In other words, when the capacitor current is cut off, the instantaneous recovery voltage that occurs between the surface contacts when the fixed and movable contacts are opened is low, so the capacitor current is cut off relatively easily on one side, and on the other hand, both contacts Severe circuit conditions exist where, while the capacitor is not sufficiently opened and a complete insulation distance is established, there is a high recovery potential due to the residual charge in the capacitor between the break points, often inducing restrike. It is something to do.

However, in order to overcome this and complete point-free ignition breaker, the breaker speed must be extremely increased, but if the breaker speed increases too much, the breaker at the first current zero point will fail. If this happens, the breaking distance to reach the next current zero point will increase and the length of the arc extinguishing chamber will have to be made abnormally large. This is extremely difficult from the viewpoint of economic efficiency and practical performance.

Therefore, without increasing the breaking speed (as a means to complete the breaking), the oil existing between the surface contacts whose dielectric strength has deteriorated due to contamination caused by the arc during the first breaking is forced to be used as a source of oil flow. It is conceivable that the insulation can be quickly recovered in the event of a shutoff by powerfully injecting a stream of oil to quickly drain the oil and replace it with fresh oil.

Furthermore, even in the arc extinguishing chamber equipped with only the forced oil flow source mentioned above, the speed of the forced oil flow generated can be increased by increasing the volume of the cylinder to an abnormal degree and increasing the capacity of the forced oil flow source. However, such an abnormal increase in the capacity of the forced oil flow source will result in an increase in the force in the opposite direction to the input force of the breaker, so in order to overcome this, It is necessary to increase the input force of the breaker, and to consider strengthening each part of the breaker to withstand these stresses. .

In other words, there is a natural limit to the capacity increase of the forced oil flow source.

In view of the above points, the present invention aims to increase the forced oil flow generation source within the permissible range of the circuit breaker equipped with it, and without adding any special equipment outside the arc extinguishing chamber. By elucidating the direction and acceleration of the forced oil flow generated by the forced oil flow source, it is possible to effectively and appropriately utilize the forced oil flow to its fullest extent, and even to generate small advancing currents, which are considered extremely difficult, without re-pointing. The present invention proposes an arc extinguishing chamber that interrupts the arc when it occurs and maintains such interrupting performance permanently.A few embodiments according to the present invention will be described below with reference to the drawings.

FIG. 2 is a longitudinal sectional view of the arc extinguishing chamber immediately after the movable contact is separated, showing an embodiment according to the present invention, in which numeral 1 indicates the arc extinguishing chamber body, outer cylinder 2. A bottom plate 3, an arc-extinguishing plate group 4 in which a plurality of arc-extinguishing plates of various shapes are stacked, and an arc-extinguishing plate formed by integrally fixing a plurality of arc-extinguishing plates of various shapes placed on top of the group 4. unit 5
and a fixed contact plate disposed on top of the fixed contact plate.

As shown in FIG.
aj 2b, 3b, 4c.

They are stacked in the order of sb, 6b, 7b, and 8e in each direction shown in the figure and are fixed together. A pressure chamber 8 having a fan-shaped cross section and serving as an oil passage is formed at a location opposite to the oil lower. When the arc-extinguishing plates are stacked and the arc-extinguishing plate unit 5 is assembled, the fan-shaped pressure chamber 8 is horizontally moved. A pressure chamber 8 is configured as a longitudinally long oil flow path for injection.

In addition, each of the arc extinguishing plates a, by Cm ds e has through holes 10, 11, and 12° 13 formed in their centers having different sizes and shapes through which the movable contact 9 moves when opening and closing. The arc extinguishing plate has an oil injection port 14 that connects the fan-shaped pressure chamber 8 and the through hole 11 in the center, and the width of the oil injection port 14 that communicates with the outside of the arc extinguishing plate is narrower than the through hole 11 in the center. Second oil injection ports 15 each having a cross-sectional area larger than the cross-sectional area of the injection ports 14 are formed in the diametrical direction of the arc-extinguishing plate.

Next, the fixed contact 6 includes a plurality of fixed contact pieces 16, and a fixed contact base 17 which fits into contact with the upper part of the fixed contact pieces 16.
The fixed contact piece 16 is connected to the fixed contact base 17 and the movable contact 9
A compression spring 18 for press-contacting the peripheral surface of the fixed contact base 17 and a spring support 19 for fitting and supporting the compression spring 18. A through hole 20 is formed through which the contact 9 can pass.

Reference numeral 21 denotes a forced oil flow generation source provided above the fixed contact 6 in the arc extinguishing chamber main body 1, and is composed of the following various members.

That is, 22 is a cylinder communicating with the arc extinguishing chamber main body 1;
3 is the arc extinguishing plate unit 5 at one end of the bottom surface of the cylinder 22;
A communication hole is provided at a position facing the pressure chamber 8, and its cross-sectional area is such that the pressure in the pressure chamber 8 is approximately equal to the hydraulic pressure generated by the downward movement of the piston 24 of the forced oil flow generation source 21. It is formed to be much larger than the cross-sectional area of the injection port 14.

24 is a piston disposed in the cylinder 22, 25 is an oil flow hole provided in the piston 24, 26 is a piston rod, and 27 is a support that is slidably fitted onto the piston rod 26 between the piston rod 26 and the piston 24. When the piston 24 is ascending, the valve plate is separated from the piston 24 to allow oil to pass through the communication hole 25, and when the piston 24 is descending, it is in close contact with the piston 24 to prevent oil from flowing.

Reference numeral 28 is a coil-shaped return spring that applies restoring elasticity to lower the piston 24 when the piston is shut off, and 29 is a gap between the through hole 20 and the piston rod 26 and serves as an oil injection port for forced oil flow.

Numeral 30 is a bolt for fixing the cylinder 22 to the outer cylinder 2 of the arc-extinguishing chamber main body 1, and 31 is a bolt for fixing the arc-extinguishing chamber to the bushing bottom seat 32.

In the above configuration, when the movable contact 9 starts to open and separate, the push-up blade that was pushing up the piston 24 via the piston rod 26 is removed by the movable contact 9, so the piston 24 is moved together with the piston rod 26. >if
It is pushed down by the restoring elasticity of the f spring 28.

At this time, the valve plate 27 is connected to the pressing blade of the piston 24 and the cylinder 2.
The piston 24 is pushed up in close contact with the lower surface of the piston 24 by the push-up blade due to the pressure reaction force of the oil below the piston 24 in the piston 2.
Since the oil flow hole 25 provided in the piston 24 is closed, the oil below the piston 24 is pressed as the piston 24 descends.

The pressed oil is then forced out into the upper part of the arc extinguishing chamber main body 1 through the oil injection port 29 and the communication hole 23 formed by the gap between the through hole 20 at the center of the fixed contact base 17 at the bottom of the cylinder 22 and the piston rod 26. The oil flow that has passed through the spout 29 passes directly down the moving path of the movable contact 9 and flows from the tip of the fixed contact piece 16 to the tip of the movable contact 9 that is being released. The field is ejected in the axial direction relative to the oncoming arc.

Further, the oil flow passing through the communication hole 23 passes through the upper part of the arc extinguishing chamber main body 1, that is, the outer periphery of the spring support 19, and then passes through the pressure chamber 8 provided in the arc extinguishing plate unit 5, which serves as a long fan-shaped oil flow path in the vertical direction.
The arc-extinguishing plate 2b is press-fitted into the arc-extinguishing plate 2b and constitutes the arc-extinguishing plate unit 5.
, 3b and 5b, small diameter injection port 14 provided in 6b
The liquid is turned in a direction transverse to the arc, accelerated, and injected between the fixed and movable contacts that are being separated.

Note that the cross-sectional area of the communication hole 23 (S□) injection port 14 = 14
', 11') The cross-sectional area (S2) and the cross-sectional area (S3) of the injection ports 15.7 are provided as St > 82 < 83, so the injection ports 14.14', 14 '
! The oil flow at the overpoint is the fastest.

Therefore, the tip of the movable tangent angle member 9 is washed by this fast oil flow, the arc and the traces of contamination caused by the arc are quickly removed, and the insulation recovery force is increased (quick current interruption is performed).

Next, the oil whose dielectric strength has deteriorated due to the arc is removed from the arc extinguishing plate 2b.
, 3b, 5b, and 6b, and is ejected to the outside of the arc extinguishing chamber faster than the first oil injection lower.

4 and 6 are longitudinal cross-sectional views of the arc extinguishing chamber immediately after the movable contact is released, showing another embodiment. The main points different from the arc extinguishing chamber in FIG. It is in the configuration of

That is, in the arc-extinguishing chamber shown in FIG. 2, a plurality of arc-extinguishing plates 1a to 7e constituting the arc-extinguishing plate unit 5 are each provided with fan-shaped through holes 8, and arc-extinguishing plates 2b, 3b, 5b, and 6b are provided with injection ports, respectively. 14 are provided and stacked to form an oil lateral flow passage and accelerate the oil flow, whereas in the arc extinguishing chambers of FIGS. 4 and 6, arc extinguishing plate units 5' and As a plurality of arc-extinguishing plates constituting the arc-extinguishing plate, the fan-shaped through hole 8 and the injection port 1 in the arc-extinguishing plate shown in FIG.
A plurality of arc extinguishing plates 1a'12b's3c's shown in FIGS. 5 and 7 with the parts corresponding to 4 cut out and deleted
4c's sd', 6t/, and 7c' are provided and stacked one after another, and the space of this cutout part is provided with a shape that can add light, and a longitudinally long oil flow passage formed in a vertical groove is formed. and an injection chamber 8e' which also includes an injection port 14' and a longitudinally long oil flow passage and an injection port 11.
and 8e'', which are fully added to the space of the cutout portion to constitute the oil cross-flow passage,
And the oil flow is accelerated.

In addition, in the arc extinguishing chamber shown in FIG. 4, the injection port 14' of the injection chamber 80' constituting the arc extinguishing plate unit cf has a sixth The difference exists in that the injection port 14' of the injection chamber 8/ constituting the arc extinguishing plate unit 5' in the illustrated arc extinguishing chamber is configured in a cylindrical shape extending outward from the wall of the injection chamber 8/.

However, although there are some differences in the configuration of the three implementation rows explained above, all of the above are lateral flow for blowing the forced oil flow sent from the forced oil flow generation source in the upper part of the arc extinguishing chamber to the breaking point. A consistent common feature is that the passage and the injection port as an acceleration configuration are provided within the arc-extinguishing plate unit.

As detailed above, the feature of this arc extinguishing chamber is that the forced oil flow generation source installed at the top of the arc extinguishing chamber is driven in the axial direction directly below the moving path of the movable contact in the center of the arc extinguishing chamber. Due to the cross-flow passage provided in the arc-extinguishing chamber and the acceleration configuration, an oil flow that accelerates cross-flowing from the opposite side of the oil nozzle across the center of the arc-extinguishing chamber toward the oil nozzle. The point where an oil flow is simultaneously generated and a jet is made between the fixed and movable contacts during separation, the cross-sectional area (Sl) of the communication hole 23, and the injection port 14° 14
The cross-sectional area (S2) of ', 14' and the cross-sectional area (S3) of the oil injection ports 15, 7 are set to be 81 > 82 < 83.

In the above description, only the cutting off of a small leading current is explained in detail, but it goes without saying that it has the cutting ability against a general short-circuit large current.

Next, an experimental example according to the present invention will be shown. In the arc extinguishing chamber shown in Fig. 2, it is possible to completely shut off the arc without repointing at the current initial opening speed of about 80, and the same (about 70%) It has descended and achieved good results with no re-point firing.

Incidentally, the arc extinguishing chambers shown in FIGS. 4 and 6 also achieve almost the same effect.

According to the present invention having the above configuration, as described in detail, the forced oil flow generated by the drive of the generation source is effectively and appropriately treated inside the arc extinguishing chamber, and this is utilized to the maximum extent to prevent the flow of oil during disconnection. By extinguishing the arc by extinguishing the arc between the solid contacts, the contaminated and degraded oil at the breaker point can be rapidly replaced with fresh oil, which speeds up insulation recovery at the breaker point.
Therefore, even if there is a high recovery voltage due to the residual charge in the capacitor, it will not induce a restrike, and it is possible to cut off a small advance current without restriking under severe circuit conditions. Since there is no space in the path of the generated arc, and it is located further away from the arc, there is no change in the winding speed or direction due to burnout caused by the arc, resulting in a larger cross-sectional area or abnormal deformation. Also, the cross-sectional area of the first and second oil nozzles becomes larger due to burnout due to arcing (even if the cross-sectional area of the nozzle is smaller than the cross-sectional area of each of the first and second oil nozzles) , and by permanently maintaining the relationship that the cross-sectional area of the communication port between the pressure chamber 8 and the forced oil flow source is much larger than the cross-sectional area of the injection port, the blowout effect of the forced oil flow does not change. In other words, it is possible to obtain an arc extinguishing chamber whose breaking performance does not change.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a conventional arc-extinguishing chamber immediately after the movable contact is opened, and FIGS. 2 and 3 are longitudinal cross-sectional views of the arc-extinguishing chamber immediately after the movable contact is opened, showing an embodiment according to the present invention. A top view and an exploded plan view of the arc-extinguishing plate unit, FIGS. 4 and 6 are longitudinal sectional views of the arc-extinguishing chamber immediately after the movable contact is opened, and FIGS. 5 and 7 are respectively showing other implementation rows. It is also an exploded plan view of the arc-extinguishing plate unit. 1... Arc-extinguishing chamber body, 5... Arc-extinguishing plate unit, 6...
- Fixed contact, 7... First oil injection port, 8... Pressure chamber, 9... Movable contact, 14, 14', 14'... Injection port, 15... Second Oil injection port, 21... Forced oil flow source, 22... Cylinder, 24... Piston, 28
...Return spring, 29...Spout port.

Claims (1)

[Scope of Claims] 1. An arc extinguishing chamber main body 1 having a first oil injection lower on a side wall and a movement path for a movable contact 9 penetrating through the center, and the movable contact 9 contacting and opening. and a fixed contact 6 to be separated,
Furthermore, above the fixed contact 6, there is a cylinder 22 communicating with the inside of the arc extinguishing chamber main body 1 through a communication hole 23;
a forced oil flow generation source 21 consisting of a piston 24 disposed in the interior of the movable contactor 2 and pushed up by the closing action of the movable contact 9; and a return spring 28 for applying restoring elasticity to the piston 24 so as to lower the piston 24 when the movable contact 9 is shut off. In the arc extinguishing chamber, the communication hole 23 is provided in the arc extinguishing plate unit 5 formed of a plurality of arc extinguishing plates provided above in the arc extinguishing chamber main body 1 and on the opposite side of the first oil injection lower. A pressure chamber 8 communicating with the lower part of the cylinder 22, an injection port 14, 14', 14'' of a small cross-sectional area penetrating the peripheral wall of the pressure chamber 8 facing the movement path of the movable contact 9, and the injection Mouth 14.14
'. A second oil injection port 15 connected to the first oil injection lower constituted by the arc extinguishing plate unit 5 is provided at a position crossing the movement path of the movable contact 9 from 14', and The cross-sectional area of the injection ports 14, 14', 14' is formed to be smaller than the cross-sectional area of each of the first and second oil injection lowers 15, and the pressure in the pressure chamber 8 is set to the forced oil flow generation source. The injection ports 14.14', 14'', l are approximately equal in pressure to the hydraulic pressure produced by the piston 24 in the piston 21.
: An arc extinguishing chamber characterized in that the cylinder 22 of the forced oil flow source 21 and the pressure chamber 8 are connected by the communication hole 23 having a much larger cross section.