Arc extinguishing and short circuit current resisting direct-current relay

Abstract

The invention discloses an arc extinguishing and short circuit current resisting direct-current relay, which comprises two static contact leading-out ends, a straight sheet type movable contact spring, a push rod component and three pieces of magnetic steel. Two of the three pieces of magnetic steel are respectively arranged at the outer sides of two sides of the width of the movable contact spring and are positioned at the position corresponding to one movable and static contact, and the magnetic poles of one surfaces of the two pieces of magnetic steel, which face the movable and static contact, are set to be the same; the other piece in the three pieces of magnetic steel is arranged on the outer side of one side of the length of the movable contact spring and is positioned at the position corresponding to the other movable and static contact; and the pole surface of the other piece of magnetic steel is approximately vertical to the pole surfaces of the two pieces of magnetic steel,so that the Lorentz force generated by the movable contact spring in an arc extinguishing magnetic field formed by the three pieces of magnetic steel is approximately zero. The defect that the short circuit current resisting capability of the product is reduced due to an arc extinguishing magnetic field can be eliminated.

Description

technical field [0001] The invention relates to the technical field of relays, in particular to a DC relay capable of extinguishing arcs and resisting short-circuit current. Background technique [0002] The anti-short-circuit capability of DC relays is a relatively difficult indicator at present. At present, the anti-short-circuit current of high-voltage DC relays has reached the level of 16kA. When the short-circuit current passes through the movable and static contacts, the electric repulsion generated between the movable and static contacts will cause the contacts to repel, which will eventually lead to severe arcing and make the relay invalid. The root of solving short-circuit resistance is to ensure that the contacts are in reliable contact without bouncing off. [0003] The high-voltage DC relay with direct-acting magnetic circuit structure in the prior art usually adopts magnetic blowout arc extinguishing, that is, a magnetic steel is arranged around the contact poi...

AI Technical Summary

Problems solved by technology

[0003] The high-voltage DC relay with direct-acting magnetic circuit structure in the prior art usually adopts magnetic blowout arc extinguishing, that is, a magnetic steel is arranged around the contact point of the two moving and static contacts, and the magnetic field formed by the magnetic steel is used to realize magnetic blowout arc extinguishing. Although the magnetic arc extinguishing is beneficial to the arc extinguishing of the relay and improves the life capacity, it will also cause a problem that the energized moving reed will be subjected to the Lorentz force under the magnetic field of the magnetic blowing arc extinguishing. As a result, the Lorentz force on the moving reed under the magnetic blowout magnetic field is downward, so that the force on the moving reed is the resultant force of electric repulsion + Lorentz force. Once the resultant force is greater than the contact pressure generated by overtravel, Then the dynamic and static contacts (moving and static contacts) will not be able to reliably contact and close, resulting in the failure of the bounce and arc

[0004] The existing magnet arc extinguishing layout of the DC relay mainly includes two magnet arc extinguishing structures and four magnet arc extinguishing structures. A four magnet arc extinguishing structure in the prior art is to arrange four magnets respectively On both sides of the width of the moving reed, the positions corresponding to the moving and static contacts, and the magnetic poles on the side facing the moving and static contacts of the two magnets corresponding to the same moving and static contacts are set opposite, and corresponding to the width of the moving reed The magnetic poles of the two magnets on the same side facing the corresponding side of the moving and static contacts are set to be the same. The disadvantages of this layout of the magnets: one is that the moving reed is affected by the Loren The force is downward, which will affect the reliable contact between the dynamic and static contacts, resulting in the failure of the pop-up arc and reducing the short-circuit resistance of the product; the second is that there are polarity requirements for the load wiring, forward arc extinguishing and reverse extinguishing The effect of the arc is quite different

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