JPH0146967B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrode part structure of a switch capable of switching a load.

Conventionally, as shown in FIGS. 1 and 2, the electrode structure of a switch capable of switching a load has been a tulip-shaped female electrode supported by an insulator 2 having an arc extinguishing chamber 1 in its opening. There was an electrode 3 in which a rod-shaped male electrode 5 having an arc-extinguishing rod 4 at its tip was formed so that it could be inserted into and removed from the electrode 3.

When releasing a load in a switch having this type of electrode structure, as shown in FIG. 2, the male electrode 5 is separated from the female electrode 3 at a speed v in the direction of the arrow. This is done by Here, when the distance between the electrodes reaches X as shown in the same figure, when the arc current of the AC arc 6 flowing between the electrodes 3 and 5 passes through the zero point, the distance between the electrodes 3 and 5 at that time is If the re-electromotive voltage can be withstood, the current interruption in this electrode section is successful.

However, when the distance between electrodes is X, current interruption is not successful and the current is re-ignited, the male electrode 5 is further spaced apart and the current is interrupted at the next current zero point where the distance between electrodes is increased. This results in a delay in cutting off the current.

Such a restriking phenomenon often occurs even when the distance X obtained by the electrodes 3 and 5 is a necessary and sufficient distance estimated from the relationship between the gap length and the dielectric breakdown voltage of the air. It is acceptable.

The purpose of this invention is to improve potential concentration near the electrode due to non-uniform potential distribution along the surface of the dielectric (arc extinguishing rod and arc extinguishing tube), which is cited as one of the causes of the above-mentioned restriking phenomenon. .

Hereinafter, a third embodiment embodying this invention will be described.
4 and 4, there is an arc extinguishing rod 11 at the tip of the fixed side of the electrode part of the switch of this embodiment.
A round rod-shaped male electrode 12 to which is fixed is arranged,
The tip corner of the male electrode 12 has a chamfered portion 12a.
is formed. Outside the male electrode 12, a cylindrical synthetic resin barrier 13 is concentrically spaced and protrudes from the side opposite to the male electrode 12 so as to overlap the electrode 12 at its tip. It is arranged.

On the outside of the barrier 13, cylindrical metal fixed shield electrodes 14 are concentrically spaced and protrude from the same side as the male electrode 12 so that the tip protrudes longer than the tip of the male electrode 12. The tip of the shield electrode 14 is covered with an insulating cap 15 made of an insulating material such as resin or rubber in order to alleviate potential concentration at the tip of the shield electrode 14.

A movable electrode rod 1 that approaches and moves away from the arc extinguishing rod 11 is provided on the movable side corresponding to the fixed side.
6 is provided, and a reduced diameter portion 17 is formed at the tip of the movable electrode rod 16. An annular support member 18 with a male thread cut on the outer periphery is fitted into the base end of the reduced diameter portion 17, and a cylindrical shield electrode 19 made of metal is fitted on the outer periphery of the support member 18. It is screwed on the inner periphery of the base end. Note that a male thread is cut on the outer periphery of the tip of the shield electrode 19.

An arc extinguishing cylinder 21 that can be fitted onto the outer periphery of the distal end of the shield electrode 19 with a narrow gap between the arc extinguishing rod 11 and the male electrode 12 is screwed onto the inner periphery of the proximal end thereof. Further, the arc extinguishing cylinder 21 is loosely fitted to the inner periphery of the barrier 13. A groove 20 into which the tip of the shield electrode 19 is inserted is provided at the base end of the arc-extinguishing cylinder 21.

A tulip-shaped female electrode 22 is fitted at the distal end of the reduced diameter portion 17 at its proximal end.
A contact portion 22a into which the male electrode 12 is inserted and removed is provided on the inner periphery of the tip end of the female electrode 22 and protrudes inward, and the outer periphery of the base end and tip portion of the female electrode 22 is provided. An annular spring 23 is wound around the annular spring 23 to ensure contact pressure of the female electrode 22 against the movable electrode rod 16 and the male electrode 12.

The light end of the shield electrode 19 is formed to protrude from the tip of the female electrode 22 toward the arc extinguishing tube 21 side, and the support member 18 and the female electrode are formed at the tip of the reduced diameter portion 17 of the movable electrode rod 16. A flanged screw 24 is screwed together to prevent the part 22 from coming off the reduced diameter part 17.

Now, in the opening/closing electrode section configured as described above, when the movable electrode rod 16 is opened as shown in FIG. 4 from the closed state shown in FIG. 3, the male electrode 12 and the female electrode 22 An arc jumps between the tips of the arc, and when the arc current passes through the zero point, it is extinguished in the narrow gap between the arc extinguishing rod 11 and the arc extinguishing tube 21.

Next, immediately after the arc is extinguished, both the electrodes 1
The case where a re-electromotive voltage is applied between the male electrode 12 and the female electrode 2 will be explained with reference to FIGS. 5 a, b and 6 a, b.
The potential distribution between both electrodes 12 and 22 is shown by a curve with an interval of 5% when electrodes 2 are open.

As is clear from this potential distribution, the potential gradient near the electrode 22 due to the shield electrode 19 is
It is smaller than the case without the shield electrode 19 shown in Figure a. Therefore, the arc between the electrodes 12 and 22 that has been extinguished at the current zero point is extremely difficult to be re-ignited, and the current can be interrupted satisfactorily.

Furthermore, if the chamfered portion 12a is formed at the tip corner of the male electrode 12 as in this embodiment, the fifth
As is clear from Figure a, the potential concentration at the tip corner of the male electrode 12 is weakened, which works well to suppress restriking. Furthermore, as in this example,
If the shield electrode 14 is also provided on the male electrode 12 side, the concentration of potential near the electrodes 12 and 22 is further improved compared to the case where the shield electrode 14 is not provided as shown in FIG. 5B. Further, the insulating cap 15 that covers the tip of the shield electrode 14 prevents the formation of a protrusion due to breakage of the tip of the shield electrode 14.

Next, another example of the present invention will be explained according to FIGS. A shield electrode 34 is provided protrudingly.

In this alternative example configured as described above, the potential concentration within the arc extinguishing rod 33 is improved as shown in FIG. 7b. The degree of improvement is shown in Figure 5b.
This is clear from the comparison.

Note that it is also possible to provide a shield electrode projecting from the male electrode 12 of the above embodiment as shown in this other example, and to improve the potential concentration near both electrodes 12 and 22 by working with the shield electrode 19. be.

As detailed above, the opening/closing electrode structure of the present invention includes an arc-extinguishing rod at the tip, a male electrode with a chamfered portion cut out at the corner of the tip in contact with the arc-extinguishing rod, and A female electrode formed to be able to be inserted and removed; an arc extinguishing tube disposed with a narrow gap from the outer periphery of the male electrode; By constructing it with a shield electrode provided to protrude toward the electrode side, potential concentration near the electrode is improved, thereby suppressing restriking between the electrodes and achieving good current interruption. Therefore, this invention is preferable for industrial use as an opening/closing electrode part structure.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a conventional opening/closing electrode structure in a closed state, and FIG. 2 is a sectional view similarly showing an open state. FIG. 3 is a sectional view showing an embodiment of the present invention in a closed state, and FIG. 4 is a sectional view similarly showing an open state. Figure 5a is a potential distribution diagram when a shield electrode is provided for the male and female electrodes, Figure 5b is a potential distribution diagram when the male electrode does not have a shield electrode, and Figure 6a is a diagram for the female electrode. Potential distribution diagram when the electrode does not have a shield electrode,
FIG. 6b is a potential distribution diagram when there is no chamfered portion. FIG. 7a is a sectional view showing another example of the present invention, and FIG. 7b is a potential distribution diagram in FIG. 6a. Arc extinguishing rod...11,33, male electrode...12,3
2. Chamfered portion...12a, Barrier...13, Shield electrode...14, 19, 34, Insulating cap as an insulating material...15, Movable electrode rod...16,
Supporting member...18, arc extinguishing cylinder...21, 31, female electrode...22.

Claims (1)

[Claims] 1. A male electrode 12 having an arc-extinguishing rod 11 at its tip and a chamfered portion 12a cut out at the corner of the tip in contact with the arc-extinguishing rod 11; an arc-extinguishing cylinder 21 disposed with a narrow gap relative to the outer periphery of the male electrode 12; The shield electrodes 14 and 1 are provided so as to protrude from the tips of the electrodes 12 and 22 toward the other electrodes 12 and 22.
9. An electrode part structure of a switch, characterized by comprising: 2 Shield electrode 1 placed on the female electrode 22 side
9. The electrode part structure of a switch according to claim 1, wherein 9 is formed in a cylindrical shape so as to surround the circumferential side of the female electrode 22 at a certain distance. 3 Shield electrode 3 placed on the male electrode 32 side
4 is a male electrode 3 fitted in the arc extinguishing rod 33;
2. The electrode part structure of a switch according to claim 1, wherein the electrode part structure is provided protrudingly from the tip of the switch. 4 Shield electrode 1 placed on the male electrode 12 side
At the tip of 4 is an insulating material 15 made of rubber or resin.
2. The electrode part structure of a switch according to claim 1, wherein the electrode part structure of a switch is covered with a crown.