CN211088184U

CN211088184U - Direct current contactor

Info

Publication number: CN211088184U
Application number: CN201922494599.XU
Authority: CN
Inventors: 徐灿; 汤保成; 袁进
Original assignee: Zhongtai Fuan Dongguan Electronic Technology Co ltd
Current assignee: Zhongtai Fuan Dongguan Electronic Technology Co ltd
Priority date: 2019-12-30
Filing date: 2019-12-30
Publication date: 2020-07-24
Anticipated expiration: 2029-12-30

Abstract

The utility model relates to the technical field of contactors, in particular to a direct current contactor, which comprises an insulating shell, a sealing component, an electrical contact component, a mechanical transmission component and an electromagnetic driving component, wherein the insulating shell comprises a shell, an upper cover arranged at the top of the shell, a side cover plate arranged at the side surface of the shell and a shearing shield arranged at the top of the upper cover; and a guide positioning column for guiding and positioning the movable bridge plate is arranged in the insulating cover. The utility model ensures the action of the movable bridge plate and the pressure of the contact between the movable bridge plate and the static contact by arranging the gasket, the overtravel spring and the limiting clamp spring; and the reciprocating motion of moving bridge plate can be matchd through setting up the direction reference column, and the restriction takes place axle rotation range in the moving bridge plate motion, ensures that the contact reliability of moving bridge plate and static contact improves.

Description

Direct current contactor

Technical Field

The utility model relates to a contactor technical field, concretely relates to direct current contactor.

Background

The direct current contactor in the prior art mainly comprises a magnetic circuit part, a transmission part and a contact part, and nitrogen or mixed inert gas is filled in a product to extinguish arc so as to ensure the service life capability of the product. The operation action of the transmission part mainly depends on the traction and the guide of a movable iron core in a magnetic circuit system, and then the connection and the disconnection of the contact part are operated by the transmission of a metal push rod. The arc extinguishing effect of nitrogen or inert gas is not in the optimal state, the service life capability of the product is not obviously improved, and the existing direct current contactor in the industry has the defects of large power consumption, low working reliability and weak arc extinguishing capability, so the nitrogen or inert gas arc extinguishing device is not ideal from the aspects of economy and practicability.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a direct current contactor to the above-mentioned not enough among the prior art.

The purpose of the utility model is realized through the following technical scheme: a direct current contactor comprises an insulating shell, a sealing component, an electrical contact component, a mechanical transmission component and an electromagnetic driving component, wherein the insulating shell comprises a shell, an upper cover arranged at the top of the shell, a side cover plate arranged on the side surface of the shell and a shearing mouth shield arranged at the top of the upper cover;

the sealing component comprises glue and a pumping and exhausting copper pipe arranged on the shearing mouth shield;

the electric contact component comprises a static contact, a moving bridge plate, an insulating cover, an insulating plate and a magnet; the insulating cover and the insulating plate are arranged in the shell; an insulating cavity is formed between the insulating cover and the insulating plate; the static contact protrudes into the insulating cavity; the movable bridge plate is movably arranged in the insulating cavity; the magnet is arranged on the outer wall of the insulating cover, and the glue is arranged among the static contact, the insulating cover and the upper cover;

the mechanical transmission component comprises a metal push rod, a movable iron core, a counter-force spring, an over travel spring, a gasket and a clamp spring; the metal push rod is sleeved in the moving iron core; the counter-force spring is arranged between the movable iron core and the metal push rod; one end of the metal push rod stretches into the insulating cavity and is connected with the movable bridge plate through a clamp spring; the overtravel spring is arranged between the insulation cavity and the movable bridge plate; the gasket is arranged between the metal push rod and the insulating plate;

the electromagnetic driving component comprises an enameled wire, a framework, a driving circuit board, a coil terminal, an iron sheet, an iron can, a magnetic conduction ring shaft sleeve and a magnetism increasing sheet; the iron can is arranged in the shell; the framework is arranged at the bottom in the iron tank; the enameled wire is wound outside the framework; the magnetic conduction ring shaft sleeve is fixed in the framework; the movable iron core is slidably arranged in the shaft sleeve of the magnetic conductive ring; the coil terminal is respectively connected with the driving circuit board and the enameled wire; the driving circuit board is arranged on the side cover plate; the magnetizing sheet is arranged between the bottom of the framework and the iron tank; the iron sheet is arranged at the top of the framework.

The utility model is further arranged that the bottom parts of the two sides of the shell are provided with mounting bases; a metal mounting bushing is arranged on the mounting base; the height of the metal mounting bush is 0-0.5mm higher than that of the mounting base.

The utility model is further arranged that the static contact comprises a thread part, a connecting part and a contact part which are connected in sequence; the connecting part is used for being in contact with glue; the contact part is used for contacting with the movable bridge plate; a plurality of convex ribs are arranged at the top of the connecting part at intervals; the bottom of the connecting part is provided with a circle of groove.

The utility model is further arranged that a guiding positioning column for guiding and positioning the movable bridge plate is arranged in the insulating cover; and an anti-overflow groove is formed at the joint of the insulating cover and the static contact.

The utility model is further arranged that the number of the guiding positioning columns is four; the four guiding positioning columns are respectively arranged on the side faces of the two long edges of the movable bridge plate in pairs.

The utility model discloses further set up to, the insulating boot is equipped with the air flue in the junction with the insulation board.

The utility model is further arranged that the insulating shell is internally pumped with insulating gas after being vacuumized; the insulating gas is hydrogen or a mixed insulating gas mainly containing hydrogen.

The utility model discloses further set up to, the outer wall that moves the iron core is equipped with concave type air discharge duct.

The utility model is further arranged that the end part of the magnetic conduction ring shaft sleeve is provided with a gap; and a lubricating coating is arranged on the inner side of the magnetic conduction ring shaft sleeve.

The utility model has the advantages that: the utility model ensures the action of the movable bridge plate and the pressure of the contact between the movable bridge plate and the static contact by arranging the gasket, the overtravel spring and the limiting clamp spring; and the reciprocating motion of moving bridge plate can be matchd through setting up the direction reference column, and the restriction takes place axle rotation range in the moving bridge plate motion, ensures that the contact reliability of moving bridge plate and static contact improves.

Drawings

The invention is further described with the aid of the accompanying drawings, in which, however, the embodiments do not constitute any limitation to the invention, and for a person skilled in the art, other drawings can be derived from the following drawings without inventive effort.

Fig. 1 is a cross-sectional view of the present invention;

fig. 2 is a cross-sectional view from another perspective of the present invention;

fig. 3 is a schematic structural view of the static contact of the present invention;

fig. 4 is a cross-sectional view of the insulating cover of the present invention;

fig. 5 is a cross-sectional view of the insulation cover of the present invention from another perspective;

FIG. 6 is a schematic structural diagram of the movable iron core of the present invention;

fig. 7 is a schematic structural view of the dynamic magnetic conductive ring shaft sleeve of the present invention;

wherein: 11. a housing; 12. an upper cover; 13. a side cover plate; 14. a shearing port shield; 15. mounting a base; 16. A metal mounting bushing; 21. glue; 22. pumping and exhausting copper pipes; 3. static contact; 31. a threaded portion; 32. A connecting portion; 33. a contact portion; 34. a rib is protruded; 35. a groove; 41. a bridge plate; 42. an insulating plate; 43. A magnet; 5. an insulating cover; 51. an insulating cavity; 52. guiding the positioning column; 53. an anti-overflow groove; 54. an airway; 61. A metal push rod; 62. a counter-force spring; 63. an over travel spring; 64. a gasket; 65. a clamp spring; 7. a movable iron core; 71. a concave exhaust groove; 81. enamelled wires; 82. a framework; 83. a drive circuit board; 84. a coil terminal; 85. iron sheets; 86. a tin; 87. a magnetism increasing sheet; 9. a magnetic conductive ring shaft sleeve; 91. a gap; 92. and (4) lubricating the coating.

Detailed Description

The invention will be further described with reference to the following examples.

As can be seen from fig. 1 to 7, the dc contactor according to the present embodiment includes an insulating casing, a sealing member, an electrical contact member, a mechanical transmission member, and an electromagnetic driving member, where the insulating casing includes a housing 11, an upper cover 12 disposed on the top of the housing 11, a side cover 13 disposed on the side of the housing 11, and a shear shield 14 disposed on the top of the upper cover 12;

the sealing component comprises glue 21 and a pumping and exhausting copper pipe 22 arranged on the shearing mouth shield 14;

the electric contact component comprises a static contact 3, a moving bridge plate 41, an insulating cover 5, an insulating plate 42 and a magnet 43; the insulating cover 5 and the insulating plate 42 are arranged in the shell 11; an insulating cavity 51 is formed between the insulating cover 5 and the insulating plate 42; the static contact 3 protrudes into the insulating cavity 51; the movable bridge plate 41 is movably arranged in the insulation cavity 51; the magnet 43 is arranged on the outer wall of the insulating cover 5, and the glue 21 is arranged among the static contact 3, the insulating cover 5 and the upper cover 12;

the mechanical transmission component comprises a metal push rod 61, a movable iron core 7, a counter force spring 62, an over travel spring 63, a gasket 64 and a clamp spring 65; the metal push rod 61 is sleeved in the movable iron core 7; the reaction spring 62 is arranged between the movable iron core 7 and the metal push rod 61; one end of the metal push rod 61 protrudes into the insulation cavity 51 and is connected with the movable bridge plate 41 through the clamp spring 65; the overtravel spring 63 is arranged between the insulation cavity 51 and the movable bridge plate 41; the gasket 64 is arranged between the metal push rod 61 and the insulating plate 42;

the electromagnetic driving component comprises an enameled wire 81, a framework 82, a driving circuit board 83, a coil terminal 84, an iron sheet 85, an iron can 86, a magnetic conductive ring shaft sleeve 9 and a magnetism increasing sheet 87; the iron tank 86 is arranged in the shell 11; the framework 82 is arranged at the bottom in the iron can 86; the enameled wire 81 is wound outside the framework 82; the magnetic conductive ring shaft sleeve 9 is fixed in the framework 82; the movable iron core 7 is slidably arranged in the magnetic conductive ring shaft sleeve 9; the coil terminal 84 is connected with the driving circuit board 83 and the enameled wire 81 respectively; the driving circuit board 83 is arranged on the side cover plate 13; the magnetism increasing sheet 87 is arranged between the bottom of the framework 82 and the iron tank 86; the iron sheet 85 is arranged on the top of the framework 82.

Wherein the main body of the shell 11 is circular, a cup-shaped open iron can 86 is closely matched in the shell 11, an enameled wire 81 of the electromagnetic driving component is arranged at the lower area of the iron tank 86, a mechanical transmission component is arranged at the center of the enameled wire 81 and is communicated with the upper end for transmission, an electrical contact member is provided on the enamel wire 81, i.e., in the middle region of the iron can 86, and glue 21 is provided on the electrical contact member, i.e., in the top region of the iron can 86, the glue 21 completely seals the mouth of the iron can 86 and flows into the gap between the iron can 86 and the housing 11, the glue 21 seals the inside of the product, in addition, a pumping exhaust copper pipe 22 is arranged, one section of the pumping exhaust copper pipe 22 is led into the insulating cavity 51 of the electric contact component in the product, the other end of the pumping exhaust copper pipe passes through the glue 21 to be communicated with the outside, the exhaust copper pipe 22 is used for evacuating the inside of the product and filling hydrogen or insulating gas mainly containing hydrogen.

The upper cover 12 is provided with the mounting holes of the static contacts 3 and the mounting holes of the exhaust copper pipes 22 in parallel, and has a positive and negative wiring mode for marking the two static contacts 3; the thread part 31 of the static contact 3 is arranged outside the product and used for connecting a load end externally, the static contact 3 penetrates through the glue 21 sealing layer and is assembled on the plastic insulation cavity 51, and the contact part 33 at the bottom of the static contact 3 penetrates through the plastic insulation cavity 51 and enters the cavity; the insulating cavity 51 contains the main electrical contact components inside to form an arc extinguish chamber, and the two magnets 43 arranged on the two sides of the insulating cavity 51 are used for carrying out magnetic quenching on the electric arc inside the high-voltage arc extinguish chamber; the magnets 43 are arranged on two sides of a central connecting line of the static contact 3; the movable bridge plate 41 is arranged on a central connecting line of the two static contacts 3, and the movable bridge plate 41 can move to simultaneously contact the two static contacts 3 through the action of the metal push rod 61, so that the two static contacts 3 are conducted; the upper end of the metal push rod 61 fixes the moving bridge plate 41 in the high-voltage arc extinguishing cavity, and the movement of the moving bridge plate 41 and the contact pressure of the moving bridge plate 41 and the static contact 3 are ensured through the gasket 64, the over-travel spring 63 and the clamp spring 65; the lower part of the metal push rod 61 is provided with a counter-force spring 62, a movable iron core 7 and a clamp spring 65, and the bridge plate 41 and the static contact 3 are switched on and off by the attraction of the magnetized enameled wire 81 to the movable iron core 7 and the counter-force action of the counter-force spring 62 to the movable iron core 7; a round hole is formed in the center of the iron sheet 85 in the middle, the metal push rod 61 passes through the round hole of the iron sheet 85, the insulating plate 42 is arranged on the upper portion of the iron sheet 85, the insulating plate 42 is matched with the insulating cover 5 to form a relatively closed high-voltage arc extinguish chamber, a round rubber column is arranged at the bottom of the insulating plate 42 and is matched with the center hole of the iron sheet 85, the round rubber column of the insulating plate 42 plays a role in guiding and lubricating the push rod, and scrap iron generated by action friction between the metal push rod 61 and the iron sheet 85 is; the movable iron core 7 is provided with an exhaust slot, so that the air pressure resistance is reduced when the movable iron core reciprocates in the magnetic conductive ring shaft sleeve 9; the movable iron core 7 is arranged in the center of the coil assembly of the magnetizing component, and a magnetic conduction ring shaft sleeve 9 is arranged between the movable iron core and the framework 82; the magnetic conduction ring shaft sleeve 9 is a circular ring, the magnetic conductivity of the magnetic conduction ring shaft sleeve 9 is good, and a lubricating coating 92 is arranged on the surface, matched with the movable iron core 7, of the inner layer of the magnetic conduction ring shaft sleeve 9; the magnetic conduction ring shaft sleeve 9 is arranged in the center of the framework 82, and the back bottom surface is slightly higher than the bottom surface of the bobbin; the magnetic conductive ring shaft sleeve 9 is required to be in close contact with the iron can 86 in the product; before the iron can 86 is arranged in the shell, a magnetism increasing sheet 87 is arranged at the bottom of the shell, and the magnetism increasing sheet 87 is positioned between the outer side of the bottom of the iron can 86 and the inner side of the bottom of the shell 11; the framework 82 is provided with a wire inlet groove, so that the phenomenon that the enameled wire 81 is poor after being wound is avoided; the enameled wire 81 coil is connected with two ends of the enameled wire 81 and an external driving circuit board 83 through two coil terminals 84; the driving circuit board 83 can perform modulation, voltage stabilization and output to the enameled wire 81 for magnetization after being connected with an external electric signal; the driving circuit board 83 can effectively reduce the stable power consumption of the coil. The direct current contactor of the utility model inputs an electric signal to the driving circuit board 83 from the outside, the driving circuit board 83 modulates and outputs a stable direct current voltage to apply work to the enameled wire 81, the enameled wire 81 generates magnetic force after being electrified, and the movable iron core 7 is attracted by a magnetic circuit of the magnetic conduction ring shaft sleeve 9, the iron tank 86 and the iron sheet 85; the movable iron core 7 is moved by the suction force to compress the counter-force spring 62 and push the metal push rod 61, the metal push rod 61 drives the top end movable bridge plate 41 to move to connect the two static contacts 3, meanwhile, the compression overtravel spring 63 provides pressure for the contact between the movable bridge plate 41 and the static contacts 3 to ensure the contact reliability, and at the moment, the two static contacts 3 are connected with the connected load high-voltage circuit. On the other hand, when the external input electrical signal is cut off, the driving circuit board 83 stops outputting direct current, the enameled wire 81 loses current, the further enameled wire 81 loses magnetic force, at this time, the movable iron core 7 starts to return to the initial state under the action of the reaction spring 62, the movable iron core 7 returns to drive the push rod to return to act, the movable bridge plate 41 at the top end of the metal push rod 61 also starts to return to act under the limiting action of the snap spring 65, at this time, the two static contacts 3 are disconnected, and therefore the load high-voltage circuit connected with the static contacts 3 is cut.

When the external control circuit stops supplying the electric signal, the driving circuit board 83 stops inputting the electric signal and simultaneously stops outputting stable direct current, at the same time, the coil wound by the enameled wire 81 loses direct current and loses electromagnetic force, the movable iron core 7 loses magnetic attraction and then is prompted to move towards the lower part of the product to return to the initial state due to spring counterforce provided by the compression state of the counterforce spring 62, in the process, the movable iron core 7 drives the metal push rod 61 to move towards the lower part of the product due to the limiting of the snap spring 65, the movable iron core 7 moves and simultaneously drives the metal push rod 61 to move towards the lower part of the product, the push rod drives the movable bridge plate 41 to move towards the lower part of the product to return to the initial state of the movable bridge plate 41, namely, the. Further, when the moving bridge plate 41 returns, the moving bridge plate 41 is separated from the static contact 3, and at the moment, the cut-off load is direct current, a direct current arc is generated, the direct current arc can damage the moving bridge plate 41 and the static contact 3, the contact capability of the moving bridge plate 41 and the static contact 3 is affected after continuous damage, and finally the end of the service life of a product is failed. This embodiment is provided with two magnetite 43 through insulating chamber 51 outer wall, utilizes the magnetism to blow the arc extinguishing principle and shortens electric arc extinguishing time, improves product electricity life ability.

In the dc contactor according to this embodiment, the bottom of the two sides of the housing 11 is provided with the mounting base 15; a metal mounting bush 16 is arranged on the mounting base 15; the height of the metal mounting bushing 16 is 0-0.5mm higher than the height of the mounting base 15. This arrangement allows the bottom surface of the metal mounting bushing 16 to be flush with the bottom surface of the mounting base 15 during assembly, and the top surface of the metal mounting bushing 16 to leak out of the top surface of the mounting base 15.

In the dc contactor according to this embodiment, the static contact 3 includes a threaded portion 31, a connecting portion 32, and a contact portion 33, which are connected in sequence; the connecting portion 32 is used for contacting with the glue 21; the contact portion 33 is used for contacting with the movable bridge plate 41; a plurality of convex ribs 34 are arranged at the top of the connecting part 32 at intervals; the bottom of the connecting portion 32 is provided with a ring of grooves 35. The design of the structure of the convex rib 34 and the structure of the groove 35 is beneficial to improving the contact area of the static contact 3 and the glue 21, improving the rotation resistance and the pulling resistance and preventing air leakage.

In the dc contactor according to this embodiment, a guiding positioning column 52 for guiding and positioning the moving bridge plate 41 is disposed in the insulating cover 5; and an anti-overflow groove 53 is formed at the joint of the insulating cover 5 and the static contact 3. The above arrangement prevents glue 21 from flowing into the insulating cavity 51.

In the direct current contactor according to this embodiment, the number of the guiding positioning pillars 52 is four; the four guiding and positioning columns 52 are respectively arranged on the side faces of the two long sides of the movable bridge plate 41 in pairs. The arrangement can further match the reciprocating motion of the moving bridge plate 41, limit the shaft rotation range generated in the motion of the moving bridge plate 41 and ensure that the contact reliability of the moving bridge plate 41 and the static contact 3 is improved.

In the dc contactor according to this embodiment, the insulating cover 5 is provided with an air passage 54 at a connection point with the insulating plate 42. Above-mentioned setting makes the inside pump drainage gas in insulating chamber 51 more high-efficient, and effectual improvement pump drainage gas production efficiency improves product economy nature.

In the direct current contactor according to this embodiment, an insulating gas is introduced into the insulating housing after evacuation; the insulating gas is hydrogen or a mixed insulating gas mainly containing hydrogen. The hydrogen or the insulating gas mainly containing hydrogen is beneficial to improving the arc extinguishing capability when the contact is broken, thereby improving the electrical service life capability of the product.

In the dc contactor according to this embodiment, the outer wall of the movable iron core 7 is provided with a concave exhaust groove 71. In the dc contactor according to this embodiment, a gap 91 is formed at an end of the magnetic conductive ring sleeve 9; and a lubricating coating 92 is arranged on the inner side of the magnetic conduction ring shaft sleeve 9. The movable iron core 7 is a mechanical structure which needs to do a permanent reciprocating motion, and the matching gap 91 with the magnetic conductive ring shaft sleeve 9 is very small to ensure that the magnetic leakage of the product is small, so that the concave exhaust groove 71 is arranged on the movable iron core 7, the air pressure resistance in the moving process of the movable iron core 7 is small, and the movement is smooth and free from clamping stagnation. Furthermore, a lubricating coating 92 is designed on the inner layer of the magnetic conduction ring shaft sleeve 9 matched with the movable iron core 7, so that the friction resistance is reduced in the movement process of the movable iron core 7, and the movement reliability of the movable iron core 7 is improved.

It should be finally noted that the above embodiments are only intended to illustrate the technical solutions of the present invention, and not to limit the scope of the present invention, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present invention can be modified or replaced with equivalents without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A direct current contactor is characterized in that: the electromagnetic driving type electric scissors comprise an insulating shell, a sealing component, an electric contact component, a mechanical transmission component and an electromagnetic driving component, wherein the insulating shell comprises a shell (11), an upper cover (12) arranged at the top of the shell (11), a side cover plate (13) arranged on the side surface of the shell (11) and a shearing port shield (14) arranged at the top of the upper cover (12);

the sealing component comprises glue (21) and a pumping and exhausting copper pipe (22) arranged on the shearing mouth shield (14);

the electric contact component comprises a static contact (3), a moving bridge plate (41), an insulating cover (5), an insulating plate (42) and a magnet (43); the insulating cover (5) and the insulating plate (42) are arranged in the shell (11); an insulating cavity (51) is formed between the insulating cover (5) and the insulating plate (42); the static contact (3) protrudes into the insulating cavity (51); the movable bridge plate (41) is movably arranged in the insulating cavity (51); the magnet (43) is arranged on the outer wall of the insulating cover (5), and the glue (21) is arranged among the static contact (3), the insulating cover (5) and the upper cover (12);

the mechanical transmission component comprises a metal push rod (61), a movable iron core (7), a counter force spring (62), an over travel spring (63), a gasket (64) and a clamp spring (65); the metal push rod (61) is sleeved in the movable iron core (7); the reaction spring (62) is arranged between the movable iron core (7) and the metal push rod (61); one end of the metal push rod (61) extends into the insulating cavity (51) in a protruding mode and is connected with the movable bridge plate (41) through a clamp spring (65); the over travel spring (63) is arranged between the insulation cavity (51) and the movable bridge plate (41); the gasket (64) is arranged between the metal push rod (61) and the insulating plate (42);

the electromagnetic driving component comprises an enameled wire (81), a framework (82), a driving circuit board (83), a coil terminal (84), an iron sheet (85), an iron can (86), a magnetic conductive ring shaft sleeve (9) and a magnetism increasing sheet (87); the iron tank (86) is arranged in the shell (11); the framework (82) is arranged at the bottom in the iron tank (86); the enameled wire (81) is wound outside the framework (82); the magnetic conductive ring shaft sleeve (9) is fixed in the framework (82); the movable iron core (7) is slidably arranged in the magnetic conductive ring shaft sleeve (9); the coil terminal (84) is respectively connected with the driving circuit board (83) and the enameled wire (81); the driving circuit board (83) is arranged on the side cover plate (13); the magnetism increasing sheet (87) is arranged between the bottom of the framework (82) and the iron tank (86); the iron sheet (85) is arranged at the top of the framework (82);

and a guide positioning column (52) for guiding and positioning the movable bridge plate (41) is arranged in the insulating cover (5).

2. A dc contactor as claimed in claim 1, wherein: the bottoms of the two sides of the shell (11) are provided with mounting bases (15); a metal mounting bush (16) is arranged on the mounting base (15); the height of the metal mounting bush (16) is 0-0.5mm higher than that of the mounting base (15).

3. A dc contactor as claimed in claim 1, wherein: the static contact (3) comprises a threaded part (31), a connecting part (32) and a contact part (33) which are connected in sequence; the connecting part (32) is used for being in contact with the glue (21); the contact part (33) is used for contacting with the movable bridge plate (41); a plurality of convex ribs (34) are arranged at intervals on the top of the connecting part (32); the bottom of the connecting part (32) is provided with a circle of groove (35).

4. A dc contactor as claimed in claim 1, wherein: and an anti-overflow groove (53) is formed in the joint of the insulating cover (5) and the static contact (3).

5. A dc contactor as claimed in claim 1, wherein: the number of the guide positioning columns (52) is four; the four guiding and positioning columns (52) are respectively arranged on the side faces of the two long sides of the movable bridge plate (41) in pairs.

6. A DC contactor according to claim 4, characterized in that: the insulating cover (5) is provided with an air channel (54) at the joint of the insulating cover and the insulating plate (42).

7. A dc contactor as claimed in claim 1, wherein: insulating gas is introduced into the insulating shell after vacuumizing; the insulating gas is hydrogen or a mixed insulating gas mainly containing hydrogen.

8. A dc contactor as claimed in claim 1, wherein: and a concave exhaust groove (71) is formed in the outer wall of the movable iron core (7).

9. A dc contactor as claimed in claim 1, wherein: a gap (91) is arranged at the end part of the magnetic conductive ring shaft sleeve (9); and a lubricating coating (92) is arranged on the inner side of the magnetic conduction ring shaft sleeve (9).