A direct current relay capable of resisting short circuit current and arc extinction

Abstract

The application discloses a direct-current relay capable of resisting short-circuit current and extinguishing arc, which comprises a static contact lead-out end and a moving spring sheet, a fixed upper yoke iron and a lower armature which are arranged on the upper and lower sides of the moving spring sheet and can form a magnetic circuit, and a first U-shaped support which is fixedly arranged on the upper end of a push rod, and the push rod can drive the moving spring sheet and the static contact lead-out end to contact and separate during up and down movement of the push rod, so that the direct-current relay is turned on and turned off. The direct-current relay further comprises a second U-shaped support which is arranged on a static part of the direct-current relay, and the fixed upper yoke iron is fixedly arranged on the second U-shaped support.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of relays, in particular to a direct current relay capable of resisting short circuit current and arc extinguishing. BACKGROUND

[0002] The short circuit resistance of a direct current relay is a relatively difficult index at present, and the short circuit current resistance of a high voltage direct current relay has reached the level of 16kA. When the short circuit current passes through the moving and static contacts, the electrodynamic repulsion force generated between the moving and static contacts will cause the contacts to repel, eventually leading to violent arc, which makes the relay fail. The fundamental solution to short circuit resistance is to ensure reliable contact of the contacts and prevent them from repelling. The existing technology usually adds a magnetic conductive ring composed of an upper yoke and a lower armature at the moving spring piece to resist short circuit current. When the short circuit current flows through the moving spring piece, a ring-shaped magnetic field is generated around the moving spring piece. When the ring-shaped magnetic field acts on the upper yoke and the lower armature, the upper yoke and the lower armature will generate an attractive force. By fixing the upper yoke inside the top wall of the U-shaped bracket of the push rod component and fixing the lower armature on the bottom surface of the moving spring piece, the magnetic conductive ring composed of the upper yoke and the lower armature will generate an attractive force in the direction of the contact pressure of the moving spring piece, so that the moving and static contacts do not repel. The greater the short circuit current, the more concentrated the magnetic induction lines acting on the magnetic conductive ring. At this time, the instantaneous increase of the magnetic induction lines will generate a greater electromagnetic attractive force between the upper yoke and the lower armature. This short circuit resistance structure, since the upper yoke is fixed at the U-shaped bracket of the push rod component, the upper yoke will move with the movement of the push rod component. In the overtravel stage, the moving and static contacts are in contact, and the push rod component will continue to move upwards, and the spring will be compressed to generate a contact pressure. Since the upper yoke is fixed inside the top wall of the U-shaped bracket of the push rod component, a gap will be generated between the upper yoke and the lower armature, which will weaken the electromagnetic attractive force. Because the upper yoke is fixed on the moving push rod, the push rod relies on the attractive force of the core to remain stationary. When the short circuit current is large enough, the electromagnetic attractive force generated between the short circuit rings is also large, for example, reaching 105N. At this time, the attractive force of the core relies on the attractive force generated by the coil, which is only 100N. Therefore, the core will not be kept, the core will be released, and the contacts will be separated.

[0003] On the other hand, the high voltage direct current relay with a direct-acting magnetic circuit structure in the prior art usually adopts magnetic blow arc extinguishing, that is, a magnetic steel is arranged around the contact between the two moving and static contacts, and the magnetic field formed by the magnetic steel is used to realize magnetic blow arc extinguishing. Although magnetic blow arc extinguishing is beneficial to arc extinguishing of the relay and improves the service life, it also causes a problem that the moving spring piece under power will be subjected to the Lorentz force under the magnetic blow arc magnetic field. Since the magnetic blow arc magnetic circuit layout will cause the moving spring piece to be subjected to the Lorentz force downward under the magnetic blow arc magnetic field, the force acting on the moving spring piece is the resultant force of the electrodynamic repulsion force and the Lorentz force. Once the resultant force is greater than the contact pressure generated by overtravel, the moving and static contacts (moving and static contacts) will also fail to reliably contact and close, causing repelling and arc failure. SUMMARY

[0004] One of the purposes of the present application is to overcome the deficiencies of the prior art and provide a DC relay capable of resisting short-circuit current and arc extinguishing, which can increase electromagnetic attraction by improving the short-circuit structure, thereby greatly improving the short-circuit resistance of the product, and has a short-circuit current resistance of up to 16kA.

[0005] The second purpose of the present application is to overcome the deficiencies of the prior art and provide a DC relay capable of resisting short-circuit current and arc extinguishing, which can eliminate the decline in the short-circuit resistance of the product caused by the arc extinguishing magnetic field by improving the arc extinguishing magnetic circuit structure.

[0006] The technical scheme adopted by the present application to solve its technical problems is: a DC relay capable of resisting short-circuit current and arc extinguishing, comprising two static contact lead-out ends, a straight-plate type moving spring plate and a push rod component; the moving spring plate is installed in the push rod component to realize the cooperation of the dynamic contacts at both ends of the moving spring plate with the static contacts at the bottom ends of the two static contact lead-out ends under the action of the push rod component; the DC relay further comprises a fixed upper yoke, a following upper yoke and a lower armature; the fixed upper yoke is fixed above the push rod component at a position corresponding to the two dynamic contacts of the moving spring plate, the following upper yoke is fixed in the push rod component above the moving spring plate at the position, and the lower armature is fixed to the bottom end surface of the moving spring plate at the position; the fixed upper yoke, the following upper yoke and the lower armature are respectively distributed along the width of the moving spring plate, and when the contacts are closed, the two ends of the lower armature are respectively close to or in contact with the two ends of the fixed upper yoke and the following upper yoke, thereby forming two magnetic conduction rings on the width of the moving spring plate, and when a large current fault occurs in the moving spring plate, electromagnetic attraction in the direction of contact pressure is generated to resist the electrodynamic repulsion force between the moving spring plate and the static contact lead-out end caused by the fault current.

[0007] The two magnetic conduction rings partially overlap each other.

[0008] The push rod component comprises a first U-shaped bracket in an inverted shape, a spring, a spring seat and a push rod, the top of the push rod is fixed to the spring seat, the bottom of the first U-shaped bracket is fixed to the spring seat, the following upper yoke is fixed to the inner side of the top wall of the first U-shaped bracket, and the spring is arranged between the lower armature at the bottom end of the moving spring plate and the spring seat.

[0009] The bottom end of the lower armature is provided with a mounting groove for cooperating with the spring, and the thickness of the lower armature is greater than the thickness of the following upper yoke.

[0010] The fixed upper yoke iron and the following upper yoke iron are in the shape of a character, the lower armature is in the shape of U, the top wall of the first U-shaped support is provided with a through hole for the two side walls of the U-shaped lower armature to pass through upward and contact or be close to the fixed upper yoke iron above; the U-shaped lower armature and the fixed upper yoke iron and the following upper yoke iron in the shape of a character form two partially overlapped magnetic conductive rings.

[0011] The two side walls of the U-shaped lower armature are further provided with steps, the parts on the steps of the two side walls of the U-shaped lower armature form convex parts to pass through the through hole of the top wall of the first U-shaped support and contact or be close to the fixed upper yoke iron to form one magnetic conductive ring, the steps of the two side walls of the U-shaped lower armature contact or are close to the following upper yoke iron to form another magnetic conductive ring, and the two magnetic conductive rings are overlapped at the lower armature.

[0012] The two ends of the following upper yoke iron are respectively provided with notches for the convex parts of the lower armature to be accommodated, and the inner side of the notches is provided with a convex part capable of being clamped with the through hole of the top wall of the first U-shaped support.

[0013] The direct current relay further comprises a yoke plate, the first U-shaped support, the spring and the spring seat of the push rod component are located on the yoke plate, the push rod of the push rod component passes through the through hole of the yoke plate downward and is fixed with the moving iron core below the yoke plate; the second U-shaped support in an inverted shape is mounted on the yoke plate, the top wall of the second U-shaped support is arranged at the fixed position of the fixed upper yoke iron, and the fixed upper yoke iron is fixed to the inner side of the top wall of the second U-shaped support.

[0014] The second U-shaped support is made of anti-magnetic material or weak magnetic conductive material.

[0015] The thickness of the fixed upper yoke iron is greater than or equal to the thickness of the lower armature.

[0016] In the direct current relay, a magnetic steel for arc extinguishing is further arranged beside the contact; the magnetic steel for arc extinguishing is two blocks, the two blocks of magnetic steel are respectively arranged at the positions corresponding to the moving and static contacts outside the length of the moving spring piece, and the magnetic poles of the opposite sides of the two blocks of magnetic steel are opposite.

[0017] Two U-shaped yoke clamps are further included, the bottom walls of the U-shaped yoke clamps are respectively connected with the opposite sides of the two blocks of magnetic steel, and the end parts of the two side walls of the U-shaped yoke clamps are respectively located at the positions opposite to the corresponding moving and static contacts.

[0018] Two U-shaped yoke clamps are further included, the bottom walls of the U-shaped yoke clamps are respectively connected with the opposite sides of the two blocks of magnetic steel, and the end parts of the two side walls of the U-shaped yoke clamps are respectively located at the positions opposite to the corresponding moving and static contacts.

[0019] Two U-shaped yoke iron clamps are further included, the bottom walls of the U-shapes of the two yoke iron clamps are respectively fitted on the two sides of the width of the moving spring leaf, and the end heads of the two side walls of the U-shapes of the two yoke iron clamps are respectively connected with the opposite sides of the two magnetic steels.

[0020] The direct-current relay further comprises magnetic steels for arc extinguishing beside the contacts; the magnetic steels for arc extinguishing are three, two of the three magnetic steels are respectively arranged on the outer sides of the two sides of the width of the moving spring leaf and are located at positions corresponding to one of the moving and static contacts, and the magnetic poles of the side of the two magnetic steels facing the moving and static contacts are the same; the other magnetic steel of the three magnetic steels is arranged on the outer side of one of the sides of the length of the moving spring leaf and is located at a position corresponding to the other moving and static contact, and the pole surface of the other magnetic steel is substantially perpendicular to the pole surfaces of the two magnetic steels.

[0021] The magnetic pole of the side of the other magnetic steel facing the moving and static contact is the same as the magnetic pole of the side of the two magnetic steels facing the moving and static contact, so that the arc blowing directions of the arc extinguishing magnetic fields formed by the three magnetic steels at the two moving and static contacts are respectively towards opposite outer sides.

[0022] Two U-shaped yoke iron clamps are further included, the bottom walls of the U-shapes of the two yoke iron clamps are respectively fitted on the two sides of the width of the moving spring leaf, and the end heads of the two side walls of the U-shapes of the two yoke iron clamps are respectively connected with the opposite sides of the two magnetic steels.

[0023] Compared with the prior art, the beneficial effects of the present application are:

[0024] 1. The application adopts a fixed upper yoke iron, a following upper yoke iron and a lower armature in addition to the direct current relay; the fixed upper yoke iron is fixed above the push rod part at the position corresponding to the two movable contacts of the moving reed, the following upper yoke iron is fixed in the push rod part above the moving reed at the position, and the lower armature is fixed at the bottom end surface of the moving reed at the position; the fixed upper yoke iron, the following upper yoke iron and the lower armature are distributed along the width of the moving reed respectively, and when the contacts are closed, the two ends of the lower armature are close to or in contact with the two ends of the fixed upper yoke iron and the following upper yoke iron respectively, thereby forming two magnetic conductive rings on the width of the moving reed. The structure of the application can generate electromagnetic attraction in the direction of contact pressure when a large current fault occurs in the moving reed, to resist the electrodynamic repulsion between the moving reed and the static contact lead-out end caused by the fault current; the application can greatly improve the short-circuit resistance of the product, and has a short-circuit current resistance of 16kA level. The cooperation structure of the fixed upper yoke iron, the following upper yoke iron and the lower armature has stronger short-circuit resistance than the cooperation structure of the following upper yoke iron and the lower armature. For the cooperation structure of the following upper yoke iron and the lower armature, the upper yoke iron is fixed on the following push rod, and the push rod is kept stationary by the attraction of the iron core; when the short-circuit current is large enough, the electromagnetic attraction between the short-circuit rings is also large, such as 105N, at this time the attraction of the iron core is only 100N generated by the coil, then the relay will not keep the iron core, the iron core is released, and the contacts are separated. The cooperation structure of the fixed upper yoke iron, the following upper yoke iron and the lower armature of the application, the generated attraction, part of which is allocated to the iron core holding force, part of which is allocated to the fixed yoke iron, the following upper yoke iron can short-circuit a part of the attraction at the limit breaking time, which is beneficial to breaking, and the following upper yoke iron is also not conducive to the attraction of the on-load closing, but it is small because of its small thickness.

[0025] 2. The application adopts a magnetic steel for arc extinguishing beside the contacts; the magnetic steel for arc extinguishing is two pieces, the two pieces of magnetic steel are respectively arranged at the positions corresponding to the movable and static contacts at the two ends of the length of the moving reed, and the magnetic poles of the opposite faces of the two pieces of magnetic steel are opposite. The structure of the application can make the Lorentz force generated by the moving reed in the arc extinguishing magnetic field formed by the two pieces of magnetic steel approximately zero on the basis of realizing the arc extinguishing of the magnetic steel, thereby improving the short-circuit current resistance.

[0026] 3、The DC relay capable of resisting short-circuit current and arc extinguishing according to the present application has the following advantages: the magnetic steel for arc extinguishing is arranged beside the contact; the magnetic steel for arc extinguishing is three pieces, two of the three pieces of magnetic steel are arranged on the outside of the width of the moving spring piece, and are located at the position corresponding to one of the moving and static contacts, and the magnetic poles of the surface of the two pieces of magnetic steel facing the moving and static contacts are the same; the other piece of magnetic steel is arranged on the outside of one side of the length of the moving spring piece, and is located at the position corresponding to the other moving and static contact, and the magnetic pole surface of the other piece of magnetic steel is perpendicular to the magnetic pole surface of the two pieces of magnetic steel. The structure of the present application can make the Lorentz force generated by the moving spring piece in the arc extinguishing magnetic field formed by the three pieces of magnetic steel be approximately zero, thereby improving the ability of resisting short-circuit current.

[0027] The present application will be further described in detail below in combination with the drawings and examples; but the DC relay capable of resisting short-circuit current and arc extinguishing according to the present application is not limited to the examples. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is the perspective view of the partial structure of the first example of the present application;

[0029] Figure 2 is the perspective view of the partial structure (rotated by one angle) of the first example of the present application;

[0030] Figure 3 is the exploded perspective view of the partial structure of the first example of the present application;

[0031] Figure 4 is the top view of the partial structure of the first example of the present application;

[0032] Figure 5 is the front view of the partial structure of the first example of the present application;

[0033] Figure 6 is the sectional view along the line A-A in Figure 5 ;

[0034] Figure 7 is the schematic view of the cooperation of the fixed upper yoke iron, the following upper yoke iron and the push rod part of the first example of the present application;

[0035] Figure 8 is the schematic view of the cooperation of the following upper yoke iron, the moving spring piece, the lower armature and the push rod part of the first example of the present application;

[0036] Figure 9 is the schematic view of the structure of the following upper yoke iron of the first example of the present application;

[0037] Figure 10is a configuration diagram of the first U-shaped bracket of Embodiment 1 of the present application;

[0038] Figure 11 is a configuration diagram of the lower armature of Embodiment 1 of the present application;

[0039] Figure 12 is a perspective configuration diagram of a partial configuration of Embodiment 2 of the present application;

[0040] Figure 13 is an exploded perspective configuration diagram of a partial configuration of Embodiment 2 of the present application;

[0041] Figure 14 is a plan view of a partial configuration of Embodiment 2 of the present application;

[0042] Figure 15 is a front view of a partial configuration of Embodiment 2 of the present application;

[0043] Figure 16 is a sectional view along the line B-B in Figure 15 ;

[0044] Figure 17 is a perspective configuration diagram of a partial configuration of Embodiment 3 of the present application;

[0045] Figure 18 is an exploded perspective configuration diagram of a partial configuration of Embodiment 3 of the present application;

[0046] Figure 19 is a plan view of a partial configuration of Embodiment 3 of the present application;

[0047] Figure 20 is a front view of a partial configuration of Embodiment 3 of the present application;

[0048] Figure 21 is a sectional view along the line C-C in Figure 20 ; DETAILED DESCRIPTION

[0049] Embodiment 1

[0050] Referring to Figures 1 to 11As shown, the DC relay capable of resisting short-circuit current and arc extinguishing comprises two static contact lead-out ends 1, a straight-plate type moving spring plate 2 and a push rod component 3; the moving spring plate 2 is installed in the push rod component 3 to realize the cooperation of the moving contacts at both ends of the moving spring plate 2 with the static contacts at the bottom ends of the two static contact lead-out ends 1 under the action of the push rod component 3; in the embodiment, the two end portions of the moving spring plate 2 constitute the moving contacts of the moving spring plate 2, and the bottom end portions of the static contact lead-out ends 1 constitute the static contacts of the static contact lead-out ends 1; the DC relay further comprises a fixed upper yoke 4, a following upper yoke 5 and a lower armature 6; the fixed upper yoke 4 is fixed above the push rod component 3 at a position corresponding to the two moving contacts of the moving spring plate 2, the following upper yoke 5 is fixed in the push rod component 3 above the moving spring plate 2 at the position, and the lower armature 6 is fixed at the bottom end face of the moving spring plate 2 at the position; the fixed upper yoke 4, the following upper yoke 5 and the lower armature 6 are respectively distributed along the width of the moving spring plate 2, and when the contacts are closed, the two ends of the lower armature 6 are respectively close to or in contact with the two ends of the fixed upper yoke 4 and the following upper yoke 5, so as to form two partially overlapped magnetic conductive rings on the width of the moving spring plate 2, and when a large current occurs in the moving spring plate 2, electromagnetic attraction in the direction of contact pressure is generated to resist the electrodynamic repulsion between the moving spring plate 2 and the static contact lead-out ends 1 due to the fault current.

[0051] In the embodiment, the push rod component 3 comprises a first U-shaped bracket 31 in an inverted shape, a spring 32, a spring seat 33 and a push rod 34, the top of the push rod 34 is fixed with the spring seat 33, the bottom of the first U-shaped bracket 31 is fixed with the spring seat 33, the following upper yoke 5 is fixed inside the top wall 311 of the first U-shaped bracket 31, and the spring 32 is arranged between the spring seat 33 and the lower armature 6 at the bottom end of the moving spring plate.

[0052] In the embodiment, the bottom end of the lower armature 6 is provided with a mounting groove 61 for cooperating with the spring, and the thickness of the lower armature 6 is greater than the thickness of the following upper yoke 5.

[0053] In the embodiment, the fixed upper yoke 4 and the following upper yoke 5 are respectively in the shape of a character, the lower armature 6 is in the shape of a U, the top wall 311 of the first U-shaped bracket 31 is provided with through holes 312 for allowing the two side walls of the U-shaped lower armature 6 to pass upward and contact or be close to the fixed upper yoke 4 above, and the U-shaped lower armature 6 and the fixed upper yoke 4 and the following upper yoke 5 in the shape of a character constitute two partially overlapped magnetic conductive rings.

[0054] In the embodiment, the two side walls of the U-shaped lower armature 6 are further provided with steps 62, and the parts of the two side walls of the U-shaped lower armature 6 on the steps form protrusions 63 to pass through the through holes 312 of the top wall 311 of the first U-shaped bracket 31 and contact or approach the fixed upper yoke 4 to form a magnetic conducting ring, and the steps 62 of the two side walls of the U-shaped lower armature 6 respectively contact or approach the follow-up upper yoke 5 to form another magnetic conducting ring, and the two magnetic conducting rings overlap at the lower armature 6.

[0055] In the embodiment, the two ends of the follow-up upper yoke 5 are respectively provided with notches 51 for giving way to the protrusions 63 of the lower armature 6, and the inner side of the notch 51 is provided with a boss 52 capable of being clamped with the through hole 312 of the top wall 311 of the first U-shaped bracket 31.

[0056] In the embodiment, the DC relay further comprises a yoke plate 71, the first U-shaped bracket 31, the spring 32 and the spring seat 33 of the push rod component are located on the yoke plate 71, the push rod 34 of the push rod component passes through the through hole 711 of the yoke plate 71 downward and is fixed with the moving iron core below the yoke plate; the yoke plate 71 is provided with a second U-shaped bracket 72 in an inverted shape, the top wall 721 of the second U-shaped bracket 72 is arranged at the fixed position of the fixed upper yoke 4, and the fixed upper yoke 4 is fixed on the inner side of the top wall 721 of the second U-shaped bracket 72.

[0057] The second U-shaped bracket 72 is made of anti-magnetic material or weak magnetic conducting material, such as non-magnetic stainless steel, aluminum material, etc.

[0058] In the embodiment, the thickness of the fixed upper yoke 4 is greater than the thickness of the lower armature 6. Increasing the thickness of the fixed upper yoke 4 can increase the suction force of the fixed upper yoke 4.

[0059] When the push rod component 3 is not moved upward, the upper surface of the moving spring plate 2 is abutted against the bottom surface of the follow-up upper yoke iron 5 under the action of the spring 32, and when the push rod component 3 is moved to the appropriate position, the moving contact at both ends of the moving spring plate 2 is respectively contacted with the bottom end of the two static contact lead ends 1, at this time, the steps 62 of the two side walls of the U-shaped lower armature 6 are respectively contacted with the follow-up upper yoke iron 5, and the convex part 63 of the two side walls of the U-shaped lower armature 6 is contacted or approached with the fixed upper yoke iron 4, then the push rod component 3 continues to move upward, the follow-up upper yoke iron 5 also continues to move upward with the push rod component 3, and the moving spring plate 2 cannot continue to move upward because it has been contacted with the bottom end of the two static contact lead ends 1, so that the overstroke of the contact is realized, the spring 32 provides the contact pressure, and a certain gap is formed between the bottom end of the follow-up upper yoke iron 5 and the upper surface of the moving spring plate 2, which also causes the magnetic gap between the bottom surface of the follow-up upper yoke iron 5 and the top surface of the lower armature 6. The structure of the present application can increase the suction force on the lower armature 6 by using the fixed fixed upper yoke iron 4, for example, by increasing the thickness of the fixed upper yoke iron 4 to increase the magnetic suction force, and the follow-up upper yoke iron 5 can also be used to short-circuit a part of the suction force at the limit breaking time, thereby facilitating breaking.

[0060] The DC relay capable of resisting short-circuit current and arc extinguishing of the present application adopts a fixed upper yoke iron 4, a following upper yoke iron 5 and a lower armature 6; the fixed upper yoke iron 4 is fixed above the push rod part 3 at the position corresponding to the two movable contacts of the movable spring piece 2, the following upper yoke iron 5 is fixed in the push rod part 3 above the movable spring piece 2 at the position, and the lower armature 6 is fixed at the bottom end surface of the movable spring piece 2 at the position; the fixed upper yoke iron 4, the following upper yoke iron 5 and the lower armature 6 are respectively distributed along the width of the movable spring piece 2, and when the contacts are closed, the two ends of the lower armature 6 are respectively close to or in contact with the two ends of the fixed upper yoke iron 4 and the following upper yoke iron 5, so as to form two partially overlapped magnetic conductive rings on the width of the movable spring piece 2. The structure of the present application can generate electromagnetic attraction in the direction of contact pressure when a large current occurs in the movable spring piece 2, to resist the electrodynamic repulsion between the movable spring piece and the leading end of the static contact due to the fault current; the present application can greatly improve the short-circuit resistance of the product, and has a short-circuit current resistance of 16kA. The cooperation structure of the fixed upper yoke iron, the following upper yoke iron and the lower armature of the present application has stronger short-circuit resistance than the cooperation structure of the following upper yoke iron and the lower armature. For the cooperation structure of the following upper yoke iron and the lower armature, the upper yoke iron is fixed on the following push rod, and the push rod is kept stationary by the attraction of the iron core; when the short-circuit current is large enough, the electromagnetic attraction between the short-circuit rings is also large, for example, reaching 105N, at this time the attraction of the iron core is only 100N generated by the coil, then the relay will occur that the iron core is not kept, the iron core is released, and the contacts are separated. The cooperation structure of the fixed upper yoke iron, the following upper yoke iron and the lower armature of the present application generates an attraction, part of which is shared by the iron core keeping force, and part of which is shared by the fixed yoke iron; the following upper yoke iron can magnetically short-circuit part of the attraction in the limit breaking, which is beneficial to breaking, and the following upper yoke iron is also not conducive to the attraction of the on-load connection, but it is small because of its small thickness.

[0061] Example two

[0062] Referring to Figures 11 to 16 The DC relay capable of resisting short-circuit current and arc extinguishing of the present application adopts a fixed upper yoke iron 4, a following upper yoke iron 5 and a lower armature 6; the fixed upper yoke iron 4 is fixed above the push rod part 3 at the position corresponding to the two movable contacts of the movable spring piece 2, the following upper yoke iron 5 is fixed in the push rod part 3 above the movable spring piece 2 at the position, and the lower armature 6 is fixed at the bottom end surface of the movable spring piece 2 at the position; the fixed upper yoke iron 4, the following upper yoke iron 5 and the lower armature 6 are respectively distributed along the width of the movable spring piece 2, and when the contacts are closed, the two ends of the lower armature 6 are respectively close to or in contact with the two ends of the fixed upper yoke iron 4 and the following upper yoke iron 5, so as to form two partially overlapped magnetic conductive rings on the width of the movable spring piece 2. The structure of the present application can generate electromagnetic attraction in the direction of contact pressure when a large current occurs in the movable spring piece 2, to resist the electrodynamic repulsion between the movable spring piece and the leading end of the static contact due to the fault current; the present application can greatly improve the short-circuit resistance of the product, and has a short-circuit current resistance of 16kA. The cooperation structure of the fixed upper yoke iron, the following upper yoke iron and the lower armature of the present application has stronger short-circuit resistance than the cooperation structure of the following upper yoke iron and the lower armature. For the cooperation structure of the following upper yoke iron and the lower armature, the upper yoke iron is fixed on the following push rod, and the push rod is kept stationary by the attraction of the iron core; when the short-circuit current is large enough, the electromagnetic attraction between the short-circuit rings is also large, for example, reaching 105N, at this time the attraction of the iron core is only 100N generated by the coil, then the relay will occur that the iron core is not kept, the iron core is released, and the contacts are separated. The cooperation structure of the fixed upper yoke iron, the following upper yoke iron and the lower armature of the present application generates an attraction, part of which is shared by the iron core keeping force, and part of which is shared by the fixed yoke iron; the following upper yoke iron can magnetically short-circuit part of the attraction in the limit breaking, which is beneficial to breaking, and the following upper yoke iron is also not conducive to the attraction of the on-load connection, but it is small because of its small thickness.

[0063] In the embodiment, the direct-current relay further comprises two U-shaped yoke clamps 82, the bottom walls of the U shapes of the two yoke clamps 82 are connected to the opposite sides of the two magnetic steels 81 respectively, and the end portions of the two side walls of the U shapes of the two yoke clamps 82 respectively exceed the opposite positions of the corresponding moving and static contacts and are close to each other at the middle positions between the two moving and static contacts.

[0064] The direct-current relay capable of resisting short-circuit current and arc extinguishing comprises two magnetic steels 81 arranged beside the contacts for arc extinguishing, the two magnetic steels 81 are arranged at the positions corresponding to the moving and static contacts at the two ends of the length of the moving spring piece 2 respectively, and the magnetic poles of the opposite sides of the two magnetic steels 81 are opposite.

[0065] Embodiment three

[0066] Referring to Figures 17 to 21 The direct-current relay capable of resisting short-circuit current and arc extinguishing comprises two magnetic steels 81 arranged beside the contacts for arc extinguishing, the two magnetic steels 81 are arranged at the positions corresponding to the moving and static contacts at the two ends of the length of the moving spring piece 2 respectively, and the magnetic poles of the opposite sides of the two magnetic steels 81 are opposite.

[0067] In the embodiment, the magnetic poles of the side of the other magnetic steel 91 (left) facing the moving and static contacts are the same as the magnetic poles of the side of the two magnetic steels 91 (right) facing the moving and static contacts, so that the blowing directions of the arc extinguishing magnetic field formed by the three magnetic steels 91 at the two moving and static contacts are respectively towards the opposite sides.

[0068] In the embodiment, the direct current relay further comprises two U-shaped yoke clamps 92, two side edges of the U shape of one yoke clamp 92 (right side) are connected with the back of the two magnetic steels 91 (right side) respectively, the bottom edge of the U shape of the one yoke clamp (right side) is outside the other side (right side) of the length of the moving spring 2; the bottom edge of the U shape of the other yoke clamp 92 (left side) is connected with the back of the other magnetic steel 91 (left side), two side edges of the U shape of the other yoke clamp 92 (left side) are outside the two sides of the width of the moving spring 2 respectively and correspond to the other moving static contact (left side).

[0069] The direct current relay of the present application can resist short circuit current and arc extinguishing, which is provided with magnetic steels 91 for arc extinguishing beside the contacts; the magnetic steels 91 for arc extinguishing are three, two of the three magnetic steels 91 are arranged outside the two sides of the width of the moving spring 2 and correspond to one moving static contact (right side), the magnetic poles of the back of the two magnetic steels 91 are the same; the other magnetic steel 91 of the three magnetic steels 91 is arranged outside one side (left side) of the length of the moving spring 2 and corresponds to the other moving static contact (left side), the magnetic pole of the back of the other magnetic steel 91 (left side) is perpendicular to the magnetic poles of the back of the two magnetic steels 91 (right side). The structure of the present application can make the Lorentz force generated by the moving spring in the arc extinguishing magnetic field formed by the three magnetic steels 91 be approximately zero, thereby improving the resistance to short circuit current.

[0070] The above is only the preferred embodiment of the present application, which does not limit the present application in any form. Although the present application has been disclosed as above with the preferred embodiment, it is not intended to limit the present application. Any skilled person in the art can make many possible changes and modifications to the technical solution of the present application or modify equivalent embodiments without departing from the scope of the technical solution of the present application, using the disclosed technical content. Therefore, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present application, which does not depart from the content of the technical solution of the present application, shall fall within the protection scope of the technical solution of the present application.

Claims

1. A DC relay capable of withstanding short-circuit current and arc extinguishing, characterized in that: The relay includes a stationary contact lead-out terminal, a moving spring, a fixed upper yoke and a follower upper yoke disposed on the upper side of the moving spring, a lower armature disposed on the lower side of the moving spring, and a first U-shaped bracket. The fixed upper yoke and the follower upper yoke can form magnetic circuits with the lower armature respectively. The first U-shaped bracket is fixedly mounted on the upper end of a push rod. During the up-and-down movement of the push rod, it can drive the moving spring and the stationary contact lead-out terminal to contact and separate to realize the switching on and off of the DC relay. The relay also includes a second U-shaped bracket, which is mounted on the stationary part of the DC relay. The fixed upper yoke is fixedly mounted on the second U-shaped bracket.

2. The DC relay capable of withstanding short-circuit current and extinguishing arc as described in claim 1, characterized in that: The lower armature is fixed to the bottom end face of the movable spring, and the movable spring is tensioned and abutted against the inner frame of the first U-shaped bracket by a spring.

3. The DC relay capable of withstanding short-circuit current and extinguishing arc as described in claim 2, characterized in that: The lower armature is U-shaped, and the movable spring is located between the two arms of the lower armature. The movable spring is pressed by a spring that passes through a hole at the bottom of the lower armature. There is a movement gap between the second U-shaped bracket and the lower armature. The movement gap is not less than the distance that the push rod continues to move upward after the movable spring contacts the lead-out end of the stationary contact point.

4. The DC relay capable of withstanding short-circuit current and extinguishing arc as described in claim 3, characterized in that: The lower armature has protrusions on both sides, and the first U-shaped bracket has clearance holes corresponding to the protrusions. The protrusions are located in the clearance holes, and the upper surface of the protrusions is not lower than the upper surface of the first U-shaped bracket.

5. The DC relay capable of withstanding short-circuit current and extinguishing arc as described in claim 2 or 3, characterized in that: The spring is a contact spring, with its upper end pressing against the movable spring sheet and its lower end abutting against the first U-shaped bracket or a spring seat rigidly connected to the first U-shaped bracket.

6. The DC relay capable of withstanding short-circuit current and extinguishing arc as described in claim 1, characterized in that: The movable spring is located in the inner frame of the first U-shaped bracket and can move relative to the first U-shaped bracket in the direction of movement of the push rod.

7. The DC relay capable of withstanding short-circuit current and extinguishing arc as described in claim 1, characterized in that: The stationary component is a yoke plate.

8. A DC relay capable of withstanding short-circuit current and extinguishing arc as described in claim 1, characterized in that: The lower armature is arranged in a U-shape along the width direction of the moving spring.

9. The DC relay capable of withstanding short-circuit current and extinguishing arc as described in claim 1, characterized in that: A spring seat is installed at the top of the upper end of the push rod, and the first U-shaped bracket is detachably installed on the spring seat. The moving spring and the lower armature are tensioned at the top of the first U-shaped bracket by the spring.

10. The DC relay capable of withstanding short-circuit current and extinguishing arc as described in claim 9, characterized in that: The spring seat includes an injection-molded body made of insulating material and fixedly installed on the top of the upper end of the push rod, and two connectors embedded in the injection-molded body, each connector having a connecting portion exposed in the injection-molded body.

11. The DC relay capable of withstanding short-circuit current and extinguishing arc as described in claim 9, characterized in that: The first U-shaped bracket is a U-shaped structure with the opening facing downwards, and the two side walls of the first U-shaped bracket are respectively provided with slots for installation in conjunction with the connecting part of the spring seat.

Images