CN110942938A - Contact unit for DC contactor - Google Patents
Contact unit for DC contactor Download PDFInfo
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- CN110942938A CN110942938A CN201911214541.3A CN201911214541A CN110942938A CN 110942938 A CN110942938 A CN 110942938A CN 201911214541 A CN201911214541 A CN 201911214541A CN 110942938 A CN110942938 A CN 110942938A
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- contact seat
- arc
- seat
- static
- contact
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H9/00—Details of switching devices, not covered by groups H01H1/00 - H01H7/00
- H01H9/30—Means for extinguishing or preventing arc between current-carrying parts
- H01H9/44—Means for extinguishing or preventing arc between current-carrying parts using blow-out magnet
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H50/00—Details of electromagnetic relays
- H01H50/02—Bases; Casings; Covers
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- Electromagnetism (AREA)
- Arc-Extinguishing Devices That Are Switches (AREA)
Abstract
The invention discloses a contact unit for a direct current contactor, which comprises a static contact seat and a movable contact seat, wherein a static contact blade is arranged on the static contact seat, a movable contact blade is arranged on the movable contact seat, a first spiral groove is arranged on the side wall of the static contact seat, a second spiral groove is arranged on the side wall of the movable contact seat, the spiral directions of the first spiral groove and the second spiral groove are opposite, and an arc extinguishing grating group is arranged on the outer side of the static contact seat or the movable contact seat. The direct current contactor using the contact unit does not need an external magnetic blow-out device, is high in reverse and high-capacity direct current load breaking capacity, and has the advantages of magnetic blow-out arc extinction and grid arc extinction.
Description
Technical Field
The invention relates to the field of electricity, in particular to a contact unit suitable for a direct current contactor.
Background
Without natural zero crossings, the switching off of direct currents is much more difficult than the switching off of alternating currents. At present, direct current arc extinction of a high-voltage direct-current contactor is difficult through a natural arc extinction mode, and a permanent magnet device is additionally arranged in an arc gap, so that an on-off arc moves through the permanent magnet magnetic blowing effect, the arc extinction is prolonged, and the on-off of a direct-current load is completed.
And traditional high voltage direct current contactor's permanent magnetism magnetic blow-out device sets up in inclosed arc-extinguishing chamber as an external part, and its structural style is complicated, and the cost is higher, and simultaneously, its arc extinguishing effect also has following drawback:
firstly, under the influence of high temperature of an electric arc in the direct current on-off process, the magnetic blowing device is seriously deteriorated and demagnetized under the long-term working condition, the magnetic blowing effect is obviously reduced, and the direct current on-off capacity is reduced; secondly, the magnetic blowing device is made of ferromagnetic materials such as ferrite and neodymium iron boron, more impurity gases are separated out in the switching-on and switching-off process, the saturated vapor pressure of the impurity gases is very high, the direct current arc voltage and the energy of the electric arc are increased, and the direct current load is also very unfavorable for switching-on and switching-off; thirdly, the magnetic field intensity of the traditional magnetic blowing device is not changed, and the magnetic blowing effect can not be ensured when the overload or the over-low direct current load is switched on or off.
Meanwhile, because the traditional permanent magnetic blowing system of the high-voltage direct-current contactor utilizes the unidirectional property of direct current, the magnetic blowing direction is mostly unipolar, only the direct-current arc can be ensured to be arc-extinguished towards the opposite outer side, and the reverse current switching of the contactor cannot be borne, therefore, the design of the magnetic blowing effect is ensured, the dependence on an external magnetic blowing device is reduced, and the reverse and high-capacity direct-current load on-off capacity of the direct-current contactor is improved to become a problem to be solved urgently in the design field of the direct-current contactor.
Disclosure of Invention
The technical problem to be solved by the invention is to provide a contact unit for a direct current contactor, and the direct current contactor using the contact unit does not need an external magnetic blow-out device, has high reverse and high capacity direct current load breaking capacity, and has the advantages of magnetic blow-out arc extinguishing and grid plate arc extinguishing.
The contact unit for the direct current contact comprises a static contact seat and a moving contact seat, wherein a static contact blade is arranged on the static contact seat, a moving contact blade is arranged on the moving contact seat, a first spiral groove is formed in the side wall of the static contact seat, a second spiral groove is formed in the side wall of the moving contact seat, the spiral directions of the first spiral groove and the second spiral groove are opposite, and an arc extinguishing grating group is arranged on the outer side of the static contact seat or the moving contact seat.
The invention relates to a contact unit for a direct current contact, wherein the specific mode that an arc extinguishing grid group is arranged on the outer side of a stationary contact seat is as follows: the outer side of the static contact seat is provided with a cylindrical static transition ring, one end of the static transition ring, which is close to the static contact pieces, is provided with the arc-extinguishing grid set, the arc-extinguishing grid set is cylindrical, the side wall of the arc-extinguishing grid set is provided with at least one group of grid pieces, and the arc-extinguishing grid set and the static contact seat are coaxially arranged.
The invention relates to a contact unit for a direct current contact, wherein the specific mode that an arc extinguishing grid group is arranged on the outer side of a movable contact seat is as follows: the outer side of the movable contact seat is provided with a cylindrical movable transition ring, one end of the movable transition ring, which is close to the movable contact pieces, is provided with the arc-extinguishing grid set, the arc-extinguishing grid set is cylindrical, the side wall of the arc-extinguishing grid set is provided with at least one group of grid pieces, and the arc-extinguishing grid set and the movable contact seat are coaxially arranged.
The contact unit for the direct current contact comprises a fixed contact seat, a cup opening of the fixed contact seat is arranged downwards, a first spiral groove is formed in the side wall of the fixed contact seat and penetrates through the side wall of the fixed contact seat, the first spiral groove extends spirally from the cup opening of the fixed contact seat to a cup base, a fixed contact blade is arranged at the cup opening of the fixed contact seat and is annular, and the fixed contact blade and the fixed contact seat are coaxially arranged.
The contact unit for the direct current contactor comprises a movable contact seat, a movable contact seat and a cup base, wherein the movable contact seat is cup-shaped, the cup opening of the movable contact seat is arranged upwards, a second spiral groove is formed in the side wall of the movable contact seat and penetrates through the side wall of the movable contact seat, the second spiral groove spirally extends towards the cup base from the cup opening of the movable contact seat, the number and the lift angle of the second spiral groove are consistent with those of the first spiral groove, the cup opening of the movable contact seat is provided with a movable contact piece, the movable contact piece is annular, and the movable contact piece and the movable contact seat are coaxially arranged.
The invention is applied to a direct current contactor, and after the direct current contactor is applied to the direct current contactor, in the switching-on and switching-off process of a direct current switch, the current flowing through the spiral grooves of the fixed contact seat and the movable contact seat can generate a transverse magnetic field, the transverse magnetic field can generate a transverse magnetic blowing acting force F on direct current electric arc in a gap of the fixed contact seat, the direction is perpendicular to the gap, the direct current electric arc faces outwards, and the direct current electric arc is influenced by the transverse magnetic blowing acting force F to rapidly move to an arc extinguishing grid group to realize arc extinguishing. On the other hand, under the magnetic blow of the transverse electromagnetic force F, the direct current electric arc generates centrifugal motion on the surface of the contact seat and quickly runs on the circumference, so that the contact between the direct current electric arc and the arc extinguishing grid group is increased, and the cutting arc extinguishing effect of the arc extinguishing grid group is enhanced. The direct current contactor does not need an external magnetic blowout device, and meanwhile, the non-polar direct current magnetic blowout arc extinguishing device has the advantages of reverse direction and high capacity direct current load breaking capacity.
The invention will be further explained with reference to the drawings.
Drawings
Fig. 1 is a schematic structural diagram of a dc contactor according to a first embodiment of the present invention;
fig. 2 is a schematic structural diagram of a static conductive rod, a static contact base and an arc extinguishing grid set in a dc contactor according to a first embodiment of the present invention;
FIG. 3 is a schematic structural diagram of a stationary contact block in a first embodiment of a contact unit for a DC contactor according to the present invention;
FIG. 4 is a schematic structural diagram of a stationary contact blade in a first embodiment of a contact unit for a DC contactor according to the present invention;
FIG. 5 is a schematic diagram of the self-generated transverse magnetic field generation and magnetic blow-out effect in the DC contactor according to the first embodiment of the present invention;
fig. 6 is a schematic vector diagram illustrating the principle of generating a transverse magnetic field by itself in a dc contactor according to a first embodiment of the present invention;
fig. 7 is a schematic structural view of an arc extinguishing grid set in a contact unit for a dc contactor according to a first embodiment of the present invention;
fig. 8 is a schematic diagram of a non-polar magnetic quenching adapted for reverse current in a dc contactor according to a first embodiment of the present invention;
fig. 9 is a schematic structural view of a dc contactor using a second embodiment of the present invention.
Detailed Description
Example one
As shown in fig. 1 and fig. 2 to 8, the contact unit for a dc contactor of the present invention includes a stationary contact base 12 and a movable contact base 22, wherein the stationary contact base 12 is provided with a stationary contact blade 13, the movable contact base 22 is provided with a movable contact blade 23, a first spiral groove is provided on a side wall of the stationary contact base 12, a second spiral groove is provided on a side wall of the movable contact base 22, spiral directions of the first spiral groove and the second spiral groove are opposite, and an arc extinguishing grid group 3 is provided on an outer side of the stationary contact base 12.
As shown in fig. 2, the specific manner of providing the arc extinguishing grid group 3 on the outer side of the stationary contact base 12 is as follows: the outer side of the stationary contact seat 12 is provided with a cylindrical stationary transition ring 14, one end of the stationary transition ring 14, which is close to the stationary contact blade 13, is provided with the arc extinguishing grid group 3, the arc extinguishing grid group 3 is cylindrical, the side wall of the arc extinguishing grid group 3 is provided with at least one group of grid blades, and the arc extinguishing grid group 3 and the stationary contact seat 12 are coaxially arranged.
As shown in fig. 3, the stationary contact base 12 is cup-shaped, a cup opening of the stationary contact base 12 is arranged downward, the side wall of the stationary contact base 12 is provided with the first spiral groove, the first spiral groove penetrates through the side wall of the stationary contact base 12, the first spiral groove spirally extends from the cup opening of the stationary contact base 12 to the cup base, the cup opening of the stationary contact base 12 is provided with the stationary contact blade 13, as shown in fig. 4, the stationary contact blade 13 is annular, and the stationary contact blade 13 and the stationary contact base 12 are coaxially arranged.
As shown in fig. 1 in combination with fig. 5 and 8, the movable contact seat 22 is cup-shaped, the cup opening of the movable contact seat 22 is arranged upward, the side wall of the movable contact seat 22 is provided with the second spiral groove, the second spiral groove penetrates through the side wall of the movable contact seat 22, the cup opening of the movable contact seat 22 extends spirally towards the cup base, the number and the elevation angle of the second spiral groove are consistent with those of the first spiral groove, the cup opening of the movable contact seat 22 is provided with the movable contact blade 23, the movable contact blade 23 is annular, and the movable contact blade 23 and the movable contact seat 22 are arranged coaxially.
The DC contactor of the invention has the following specific structure:
as shown in fig. 1 in conjunction with fig. 2 to 8, the direct current contactor using the present invention includes a metal case 7 having a barrel shape, and the metal case 7 is made of a ferromagnetic material having excellent magnetic permeability. The port of the metal shell 7 is provided with an insulating end cover 6 in a sealing way, and the insulating end cover 6 is made of ceramic. Two static conductive rods 11 are arranged on the insulating end cover 6, and the insulating end cover 6 is brazed with the static conductive rods 11 and the metal shell 7 after being metalized, and forms a closed cavity. The bottom end of the static conducting rod 11 extends into the metal shell 7, the bottom end of the static conducting rod 11 is provided with a static contact seat 12, a static contact blade 13 is arranged on the static contact seat 12, the bottom of the metal shell 7 is provided with a magnetic support seat 44, a movable iron core 43 is slidably mounted on the inner side of the magnetic support seat 44, an excitation coil 41 is arranged on the outer side of the magnetic support seat 44, a static yoke blade 45 and an arc extinguishing insulating cover 8 are sequentially arranged above the excitation coil 41, an operating shaft 51 is fixedly arranged on the movable iron core 43, and the operating shaft 51 is a non-magnetic conducting metal rod. The upper end of the operating shaft 51 passes through the static magnetic yoke piece 45 and the bottom of the arc extinguishing insulating cover 8 and enters the arc extinguishing insulating cover 8, a brake separating spring 52 positioned between the static magnetic yoke piece 45 and the movable iron core 43 is sleeved on the operating shaft 51, a movable conductive bar 21 is sleeved on the upper end of the operating shaft 51, and the movable conductive bar 21 can slide relative to the operating shaft 51. The upper end of the operating shaft 51 is provided with a first limiting member 55 located above the movable conducting bar 21, and the first limiting member 55 is a limiting snap spring. The arc extinguishing device is characterized in that a contact spring 53 sleeved on the operating shaft 51 is arranged below the movable conducting bar 21, the upper end of the contact spring 53 abuts against or is connected with the movable conducting bar 21, the lower end of the contact spring 53 abuts against or is connected with the side wall of the operating shaft 51, the movable conducting bar 21 is provided with a movable contact seat 22 corresponding to the static contact seats 12 one by one, the movable contact seat 22 is provided with a movable contact piece 23, the side wall of the static contact seat 12 is provided with a first spiral groove, the side wall of the movable contact seat 22 is provided with a second spiral groove, the spiral directions of the first spiral groove and the second spiral groove are opposite, the outer side of the static contact seat 12 is provided with an arc extinguishing grid group 3, and a lead of the excitation coil 41 extends out of the insulating end.
As shown in fig. 2, the static conductive rod 11 is a long conductive piece, the top is a threaded rod, and the bottom is connected with the static contact block 12.
As shown in fig. 2 and in combination with fig. 7, the specific manner of providing the arc extinguishing grid assembly 3 on the outer side of the stationary contact block 12 is as follows: the outer side of the stationary contact seat 12 is provided with a cylindrical stationary transition ring 14, and the stationary transition ring 14 is a ceramic piece, so as to avoid the electric connection between the arc extinguishing grid set 3 and the stationary conductive rod 11 during the dc arc extinguishing. The upper end of the static transition ring 14 is fixedly arranged at the bottom end of the static conducting rod 11, the lower end of the static transition ring 14 is provided with the arc extinguishing grid group 3, the arc extinguishing grid group 3 is cylindrical, the side wall of the arc extinguishing grid group 3 is provided with at least one group of grid plates, and the arc extinguishing grid group 3 and the static contact base 12 are coaxially arranged.
As shown in fig. 7, the arc-extinguishing grid assembly 3 is a cylindrical conductive member, and the upper end of the arc-extinguishing grid assembly 3 is coaxially connected with the metalized static transition ring 14 by soldering or electronic friction welding. The lower end of the arc extinguishing grid plate group 3 is divided into one or more groups of annular grid plates along the side wall, and each group of grid plates is composed of a plurality of slits.
As shown in fig. 7, the arc-extinguishing grid set 3 has its grid arrangement direction set parallel to the central axis and angled to the radial section at the same position in order to increase the effect of grid cutting the arc. The arc extinguishing grid group 3 is made of steel materials so as to increase the suction effect of the electric arc.
The upper end of the static transition ring 14 is coaxially brazed with the bottom end of the static conductive rod 11 through a metallization process, and the lower end of the static transition ring 14 is coaxially brazed with the arc extinguishing grid group 3 through a metallization process.
As shown in fig. 2 and fig. 3, the stationary contact base 12 is cup-shaped, the cup base of the stationary contact base 12 is fixedly disposed at the bottom end of the stationary conductive rod 11 in a coaxial soldering connection manner, the cup rim of the stationary contact base 12 is disposed downward, the side wall of the stationary contact base 12 is provided with the first spiral groove, the first spiral groove penetrates through the side wall of the stationary contact base 12, and the first spiral groove extends spirally from the cup rim of the stationary contact base 12 to the cup base. The stationary contact blade 13 is arranged at the cup mouth of the stationary contact seat 12, as shown in fig. 4, the stationary contact blade 13 is annular and is a conductive piece, and the stationary contact blade 13 and the stationary contact seat 12 are coaxially arranged, that is, the cup mouth of the stationary contact seat 12 is connected with the stationary contact blade 13 by brazing.
As shown in fig. 1 and combined with fig. 5 and 8, the movable contact seat 22 is cup-shaped, a cup base of the movable contact seat 22 is fixedly arranged on the movable conducting bar 21, a cup mouth of the movable contact seat 22 is arranged upward, the side wall of the movable contact seat 22 is provided with the second spiral groove, the second spiral groove penetrates through the side wall of the movable contact seat 22, the second spiral groove extends spirally from the cup mouth of the movable contact seat 22 to the cup base, the number and the rising angle of the second spiral groove are consistent with those of the first spiral groove, the cup mouth of the movable contact seat 22 is provided with the movable contact blade 23, the movable contact blade 23 is annular, and the movable contact blade 23 and the movable contact seat 22 are coaxially arranged.
The number, the lift angle and the spiral direction of the spiral grooves of the side wall of the stationary contact seat 12 and the movable contact seat 22 are not unique under the condition that the spiral directions of the spiral grooves of the side wall are opposite.
As shown in fig. 1, the movable contact bar 21 is a long conducting strip shaped like a Chinese character 'ji', and the cup portion of the movable contact 22 is soldered to the movable contact bar 21. The moving contact blade 23 and the static contact blade 13 have the same structure and are both annular conductive pieces, and the moving contact blade 23 is soldered to the moving contact base 22 at the cup mouth thereof.
The static contact seat 12 and the movable contact seat 22 are both made of metal materials with excellent conductivity, and the static contact blade 13 and the movable contact blade 23 are both made of metal contact materials with ablation resistance and fusion welding resistance.
As shown in fig. 1, the magnet support 44 is formed in a tubular shape, a first radial flange is provided at a lower end of the magnet support 44, the first radial flange is provided at a bottom of the metal shell 7, the movable iron core 43 is slidably fitted in the tubular body of the magnet support 44, the excitation coil 41 is attached to the coil bobbin 42, the coil bobbin 42 is formed in a tubular shape, a second radial flange and a third radial flange are provided at an upper end and a lower end of the coil bobbin 42, respectively, the tubular body of the coil bobbin 42 is fitted outside the tubular body of the magnet support 44, the third radial flange abuts against the first radial flange, the static yoke piece 45 and the arc extinguishing insulating cover 8 are provided above the second radial flange in this order, and the excitation coil 41 is wound around an outer side of the tubular body of the coil bobbin 42.
As shown in fig. 1, the specific manner of fixing the operating shaft 51 to the movable iron core 43 is as follows: the movable iron core 43 is provided with a vertical through hole, the inner side wall of the vertical through hole is provided with a first clamping table, the side wall of the operating shaft 51 is provided with a second clamping table, the operating shaft 51 is inserted into the vertical through hole, the first clamping table and the second clamping table are clamped with each other, the lower end of the operating shaft 51 is provided with a second limiting part 56, and the second limiting part 56 is a limiting clamp spring. The second limiting member 56 is located below the movable iron core 43 and abuts against the movable iron core 43, the upper end of the opening spring 52 abuts against the static magnetic yoke piece 45, and the lower end of the opening spring 52 extends into the vertical through hole of the movable iron core 43 and abuts against the first clamping table.
A third clamping table is arranged on the side wall of the operating shaft 51, the third clamping table can penetrate through the bottom of the arc extinguishing insulating cover 8 to be clamped with the static magnetic yoke piece 45, a limiting blocking piece 54 is sleeved on the operating shaft 51 between the upper end of the contact spring 53 and the movable conducting bar 21, the limiting blocking piece 54 is abutted against or fixedly connected with the movable conducting bar 21, the upper end of the contact spring 53 is abutted against or fixedly connected with the limiting blocking piece 54, and the lower end of the contact spring 53 is abutted against or fixedly connected with the third clamping table.
Since the third locking platform is disposed on the sidewall of the operating shaft 51, the contact spring 53 is specifically configured to contact or connect the lower end of the contact spring with the sidewall of the operating shaft 51: the lower end of the contact spring 53 abuts against or is fixedly connected with the third clamping table.
In order to ensure the safety of related personnel and the arc extinguishing effect, the metal shell 7 and the outer side of the insulating end cover 6 are provided with a sealing rubber sleeve 101. In order to ensure the safety of related personnel and avoid accidents, the bottom surface and the side surface of the sealing rubber sleeve 101 are provided with an insulating shell 102 by means of pouring, and the upper end of the static conductive rod 11 and the lead of the excitation coil 41 are both positioned outside the sealing rubber sleeve 101.
As shown in fig. 1, the operation process using the dc contactor of the present invention is as follows: when the conducting wire of the excitation coil 41 is energized (12-36V direct current is energized), the movable iron core 43 moves upward under the action of the magnetic field generated by the excitation coil 41 (in the process, the movable iron core 43 compresses the opening spring 52 toward the static yoke piece 45), the movable conducting bar 21 sleeved on the operating shaft 51 also moves upward, and then the movable contact holder 22 is driven to move upward, until the movable contact piece 23 on the movable contact holder 22 contacts with the static contact piece 13 on the static contact holder 12, and the circuit is conducted. After the power of the conductive wire of the excitation coil 41 is cut off, the movable iron core 43 drives the operating shaft 51 to move downward under the action of the elastic force of the opening spring 52 until the third clamping platform on the operating shaft 51 passes through the bottom of the arc extinguishing insulating cover 8 to be clamped with the static magnetic yoke piece 45, and at this time, the movable iron core 43 does not drive the operating shaft 51 to move downward any more. When the operating shaft 51 moves downward, the moving contact blade 23 on the moving contact base 22 and the static contact blade 13 on the static contact base 12 are separated from each other, and an arc is generated. The contact spring 53 can increase the initial opening speed in the above process, and increase the contact pressure between the moving contact blade 23 and the stationary contact blade 13, thereby reducing the resistance.
As shown in fig. 1, an air pipe 9 is embedded in the insulating end cover 6, an upper end of the air pipe 9 passes through the sealing rubber sleeve 101 and extends out of the sealing rubber sleeve 101, a lower end of the air pipe 9 passes through the insulating end cover 6 and extends into the arc extinguishing insulating cover 8, the arc extinguishing insulating cover 8 is cup-shaped, a cup base of the arc extinguishing insulating cover 8 abuts against or is connected with the static magnetic yoke piece 45, and a cup opening of the arc extinguishing insulating cover 8 abuts against the insulating end cover 6. In order to ensure the arc extinguishing effect, the arc extinguishing insulating cover 8 is made of an electric insulating material with high temperature resistance, ablation resistance and low gas generation.
In order to pre-evacuate and exhaust and fill the dc arc extinguishing gas into the closed cavity formed by the insulating end cover 6, the static conductive rod 11 and the metal shell 7, in the dc contactor of the embodiment, the insulating end cover 6 is embedded with the gas pipe 9 to pre-evacuate and exhaust and fill the dc arc extinguishing gas into the cavity. The DC arc extinguishing gas medium adopts N2, H2, SF6, He and other gases with heat conductivity and high arc potential gradient or mixed gases thereof.
Two fractures of a contactor direct-current arc extinguishing system are formed between the two groups of the static contact seats 12 and the static contact blades 13 and between the two groups of the moving contact seats 22 and the moving contact blades 23.
When the static contact seat 12 and the moving contact seat 22 are higher than the direct current on-off process of the direct current contactor, the current can generate a self-generated transverse magnetic field through the static contact seat 22 and the moving contact seat 12, and a transverse magnetic blowing effect is generated on direct current arcs between fractures. As shown in fig. 5, in the process of opening and closing the dc switch, when the moving contact base 22 and the stationary contact base 12 are separated, a dc arc is formed between the fractures of the contact bases, and assuming that one of the arc contacts forms a dc arc, the currents flowing through the spiral grooves of the moving contact base 22 and the upper and lower moving contact bases 12 of the dc arc are I1And I2From top to bottom, the arc current I of the static contact base 121With arc current I of moving contact 222The vector sum of the magnetic fields generated in the gap of the contact block is BtThe direction is perpendicular to the gap and the direct current arc is inward. The transverse magnetic field generates a transverse magnetic blowing acting force F on the direct current electric arc in the gap of the contact seat, the direction of the transverse magnetic blowing acting force F is perpendicular to the gap, the direct current electric arc is outward, and the direct current electric arc is influenced by the transverse magnetic blowing acting force F to rapidly move and realize arc extinction.
Specifically, as shown in fig. 6, the current I of the first spiral groove of the static contact base 121Decomposable into a transverse component I1tAnd a longitudinal component I1aSimilarly, the current I of the second helical groove of the movable contact 222Decomposable into a transverse component I2tAnd a longitudinal component I2a. Thus in I1tAnd I2tUnder the combined action of current and magnetic effect, a vertical inward magnetic field is generated by the gap between the moving contact seat 22 and the fixed contact seat 12, and the vector sum is BtI.e. the transverse magnetic field perpendicular to the gap dc arc.
In particular, when the moving and stationary contact blocks 22, 12 are separated, the contact block gap may generate a plurality of sets of arc contact points, and then the dc arc formed by the plurality of sets of contact points will also generate a plurality of sets of respective self-generated transverse magnetic fields, each transverse magnetic field generating the above-mentioned transverse magnetic blowing force F.
In the process of direct current breaking, direct current electric arc in the gap of the contact seat is blown by the magnetic force of the transverse electromagnetic force F, and on the one hand, the direct current electric arc is quickly pulled into the arc extinguishing grid group 3. The direct current arc is divided into a plurality of short arcs by the arc extinguishing grid group 3, so that the arc starting voltage is increased, meanwhile, the grid plates absorb a large amount of heat of the arc, and the direct current arc is rapidly cooled and extinguished through a large heat dissipation area. On the other hand, under the magnetic blow of the transverse electromagnetic force F, the direct current arc generates centrifugal motion on the surface of the contact seat, and the arc is quickly circumferentially broken, so that the contact between the direct current arc and the arc extinguishing grid group 3 is increased, and the cutting and arc extinguishing effect of the arc extinguishing grid group 3 is enhanced.
The invention is a nonpolar direct current magnetic quenching arc, and has the advantage of high on-off capability of a reverse direct current load. As shown in fig. 8, it is assumed that the currents flowing through the helical grooves of the upper and lower side stationary contact blocks 12 and the movable contact block 22 of the dc arc are I respectively1And I2The direction is from bottom to top, which is opposite to the current direction in fig. 5. Then the arc current I of the static contact holder 121With arc current I of moving contact 222The vector sum of the magnetic fields generated in the gap of the contact block is BtThe direction is perpendicular to the gap and the direct current arc is outward. The transverse magnetic field will generate a transverse magnetic blowing action force F on the gap direct current arc of the contact pedestal, the direction is still perpendicular to the gap direct current arc and outward, and the direction is the same as the direction of the electromagnetic force F in fig. 5. The transverse magnetic blowing force F guides the direct current arc to the arc extinguishing grid group 3 for cutting arc extinguishing. Therefore, the magnetic blowing effect of the self-generated magnetic field generated by the invention can be suitable for the non-polar DC load disconnection.
The nonpolar arc extinguishing effect of the invention is not changed by the change of the direction of the side wall spiral grooves of the static contact seat 12 and the moving contact seat 22.
Because the direct current has no natural zero crossing point, and the arcing time and overvoltage condition of the electric arc are harsh during the switching-on and switching-off, the coil framework 42 is made of an electric insulating material with high mechanical strength, the movable iron core 43 and the magnetic support seat 44 are both made of ferromagnetic materials with high magnetic conductivity, the movable iron core 43 and the metal shell 7 form a peripheral magnetic yoke of the excitation coil 41, and the peripheral magnetic yoke and the excitation coil 41 form a closed magnetic loop together.
In the invention, the side walls of the static contact seat 12 and the moving contact seat 22 are both provided with spiral grooves, and the spiral directions of the spiral grooves on the static contact seat 12 and the moving contact seat 22 are opposite, in the process of switching on and off the direct current switch, the current flowing through the spiral grooves on the static contact seat 12 and the moving contact seat 22 can generate a transverse magnetic field, the transverse magnetic field can generate a transverse magnetic blow-out acting force F on the direct current arc in the gap of the static contact seat 22, the direction is vertical to the gap direct current arc outwards, and the direct current arc is influenced by the transverse magnetic blow-out acting force F to rapidly move into the arc extinguishing. On the other hand, under the magnetic blow of the transverse electromagnetic force F, the direct current arc generates centrifugal motion on the surface of the contact seat, and the arc is quickly circumferentially broken, so that the contact between the direct current arc and the arc extinguishing grid group 3 is increased, and the cutting and arc extinguishing effect of the arc extinguishing grid group 3 is enhanced. The direct current contactor does not need an external magnetic blowout device, and meanwhile, the non-polar direct current magnetic blowout arc extinguishing device has the advantages of reverse direction and high capacity direct current load breaking capacity.
Example two
The difference between this embodiment and the first embodiment is: as shown in fig. 9, an arc extinguishing grid set 3 is disposed on the outer side of the movable contact base 22, that is, the arc extinguishing grid set 3 is replaced from the outer side of the stationary contact base 12 in the first embodiment to the outer side of the movable contact base 22 in this embodiment. The dynamic transition ring 24 (which has the same structure as the static transition ring 14 in the first embodiment) is metalized with ceramic and then is connected with the dynamic conducting bar 21 in a brazing mode.
The specific mode that the outer side of the movable contact seat 22 is provided with the arc extinguishing grid group 3 is as follows: the outer side of the movable contact seat 22 is provided with a cylindrical movable transition ring 24, one end of the movable transition ring 24, which is close to the movable contact blade 23, is provided with the arc extinguishing grid group 3, the arc extinguishing grid group 3 is cylindrical, the side wall of the arc extinguishing grid group 3 is provided with at least one group of grid blades, and the arc extinguishing grid group 3 and the movable contact seat 22 are coaxially arranged.
As shown in fig. 9, in the dc contactor according to the present invention, the arc extinguishing grid group 3 is provided on the outer side of the movable contact base 22 in a specific manner: the outer side of the movable contact seat 22 is provided with a cylindrical movable transition ring 24, the lower end of the movable transition ring 24 is fixedly arranged on the movable conducting bar 21, the upper end of the movable transition ring 24 is provided with the arc extinguishing grid group 3, the arc extinguishing grid group 3 is cylindrical, the side wall of the arc extinguishing grid group 3 is provided with at least one group of grid pieces, and the arc extinguishing grid group 3 and the movable contact seat 22 are coaxially arranged.
The upper end of the dynamic transition ring 24 is soldered with the arc extinguishing grid group 3 coaxially through a metallization process, and the lower end of the dynamic transition ring 24 is soldered with the dynamic conducting bar 21 through a metallization process.
The above-mentioned embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solution of the present invention by those skilled in the art should fall within the protection scope defined by the claims of the present invention without departing from the spirit of the present invention.
Claims (5)
1. A contact unit for a direct current contactor, characterized in that: the arc extinguishing device comprises a static contact seat and a moving contact seat, wherein a static contact blade is arranged on the static contact seat, a moving contact blade is arranged on the moving contact seat, a first spiral groove is formed in the side wall of the static contact seat, a second spiral groove is formed in the side wall of the moving contact seat, the spiral directions of the first spiral groove and the second spiral groove are opposite, and an arc extinguishing grid group is arranged on the outer side of the static contact seat or the moving contact seat.
2. The contact unit for the direct current contactor according to claim 1, wherein the arc extinguishing grid group is arranged on the outer side of the stationary contact seat in a specific way: the outer side of the static contact seat is provided with a cylindrical static transition ring, one end of the static transition ring, which is close to the static contact pieces, is provided with the arc-extinguishing grid set, the arc-extinguishing grid set is cylindrical, the side wall of the arc-extinguishing grid set is provided with at least one group of grid pieces, and the arc-extinguishing grid set and the static contact seat are coaxially arranged.
3. The contact unit for the direct current contactor according to claim 1, wherein the arc extinguishing grid group is arranged on the outer side of the movable contact seat in a specific way: the outer side of the movable contact seat is provided with a cylindrical movable transition ring, one end of the movable transition ring, which is close to the movable contact pieces, is provided with the arc-extinguishing grid set, the arc-extinguishing grid set is cylindrical, the side wall of the arc-extinguishing grid set is provided with at least one group of grid pieces, and the arc-extinguishing grid set and the movable contact seat are coaxially arranged.
4. The contact unit for a direct current contactor according to claim 2 or 3, characterized in that: the static contact seat is cup-shaped, the rim of a cup of the static contact seat is arranged downwards, the side wall of the static contact seat is provided with the first spiral groove, the first spiral groove penetrates through the side wall of the static contact seat, the first spiral groove extends spirally from the rim of the static contact seat to the cup base, the rim of the static contact seat is provided with the static contact blade, the static contact blade is annular, and the static contact blade and the static contact seat are coaxially arranged.
5. The contact unit for a direct current contactor according to claim 4, wherein: the movable contact seat is cup-shaped, the cup opening of the movable contact seat is arranged upwards, the side wall of the movable contact seat is provided with the second spiral groove, the second spiral groove penetrates through the side wall of the movable contact seat, the cup opening of the driven contact seat of the second spiral groove extends towards the cup base in a spiral mode, the number and the lift angle of the second spiral groove are consistent with those of the first spiral groove, the cup opening of the movable contact seat is provided with the movable contact piece, the movable contact piece is annular, and the movable contact piece and the movable contact seat are arranged in the same shaft mode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911214541.3A CN110942938A (en) | 2019-12-02 | 2019-12-02 | Contact unit for DC contactor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911214541.3A CN110942938A (en) | 2019-12-02 | 2019-12-02 | Contact unit for DC contactor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110942938A true CN110942938A (en) | 2020-03-31 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911214541.3A Pending CN110942938A (en) | 2019-12-02 | 2019-12-02 | Contact unit for DC contactor |
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| CN (1) | CN110942938A (en) |
Citations (6)
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|---|---|---|---|---|
| DE3133799A1 (en) * | 1981-08-26 | 1983-03-17 | Siemens AG, 1000 Berlin und 8000 München | "CONTACT ARRANGEMENT FOR VACUUM SWITCHES" |
| CN102522258A (en) * | 2011-12-09 | 2012-06-27 | 沈阳工业大学 | Disc-type gyromagnetic transverse blowing vacuum arc extinguish chamber |
| CN202307673U (en) * | 2011-09-27 | 2012-07-04 | 无锡浩邦科技有限公司 | AC high pressure vacuum contactor |
| CN105551881A (en) * | 2016-01-11 | 2016-05-04 | 许继集团有限公司 | Vacuum arc-extinguishing chamber, vacuum arc-extinguishing chamber contacts and direct current vacuum circuit breaker |
| CN107633978A (en) * | 2017-11-20 | 2018-01-26 | 天津平高智能电气有限公司 | A kind of Axial Magnetic Field Vacuum Interrupters with Cup Type contact |
| CN109192600A (en) * | 2018-09-25 | 2019-01-11 | 西安交通大学 | A kind of strong transverse magnetic field direct current structure of contact terminal and its direct-current vacuum arc-chutes of application |
-
2019
- 2019-12-02 CN CN201911214541.3A patent/CN110942938A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3133799A1 (en) * | 1981-08-26 | 1983-03-17 | Siemens AG, 1000 Berlin und 8000 München | "CONTACT ARRANGEMENT FOR VACUUM SWITCHES" |
| CN202307673U (en) * | 2011-09-27 | 2012-07-04 | 无锡浩邦科技有限公司 | AC high pressure vacuum contactor |
| CN102522258A (en) * | 2011-12-09 | 2012-06-27 | 沈阳工业大学 | Disc-type gyromagnetic transverse blowing vacuum arc extinguish chamber |
| CN105551881A (en) * | 2016-01-11 | 2016-05-04 | 许继集团有限公司 | Vacuum arc-extinguishing chamber, vacuum arc-extinguishing chamber contacts and direct current vacuum circuit breaker |
| CN107633978A (en) * | 2017-11-20 | 2018-01-26 | 天津平高智能电气有限公司 | A kind of Axial Magnetic Field Vacuum Interrupters with Cup Type contact |
| CN109192600A (en) * | 2018-09-25 | 2019-01-11 | 西安交通大学 | A kind of strong transverse magnetic field direct current structure of contact terminal and its direct-current vacuum arc-chutes of application |
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Application publication date: 20200331 |