CN113363116A - Direct current contactor based on short circuit resistance - Google Patents

Abstract

The invention discloses a direct current contactor based on short circuit resistance.A lower magnet yoke is arranged between an upper supporting plate and a lower supporting plate, the upper part of the lower magnet yoke is connected with the upper supporting plate through an upper armature, a flat movable contact is arranged in the lower magnet yoke, two ends of the flat movable contact extend out of the outer side of the lower magnet yoke and are respectively connected with the corresponding fixed contacts, a final pressure spring is arranged between the lower side of the flat movable contact and the lower magnet yoke, a movable iron core is arranged on the lower side of the lower supporting plate, and the movable iron core is connected with the lower magnet yoke through a lower magnet yoke connecting rod; and a group of magnetic steel sheets are respectively arranged on two sides of the joint of the flat movable contact and the corresponding fixed contact. The invention provides the attraction for the lower magnetic yoke by the electromagnetic attraction generated by the magnetic loop designed based on the electromagnetic principle, and is used for offsetting the Holm repulsion generated by the moving contact and the static contact, and the direct-acting release has simple method and adjustable short-circuit resistance.

Description

Direct current contactor based on short circuit resistance

Technical Field

The invention belongs to the technical field of switching devices, and particularly relates to a direct current contactor based on short circuit resistance.

Background

At present, a direct current contactor is a switching electric appliance product with larger usage amount in new energy fields such as new energy automobiles, photovoltaics and energy storage, but the maximum breaking capacity, namely the maximum short-circuit resistance capacity, is a difficult parameter index all the time. When a large short-circuit current (for example, 20 times of the rated current) exists, the electromagnetic repulsion generated between the moving and static contacts of the contactor can open the contacts, and a strong electric arc can be generated under the condition, so that the moving and static contacts of the contactor can be burnt out, and the contactor fails. The key point of improving the short-circuit resistance is that when larger current is generated (dozens of times of rated current), the pressure between the moving contact and the static contact is still larger than the electromagnetic repulsion, so that the contact can be closed reliably; at present, two methods are generally used for improving the closing resultant force between a moving contact and a static contact, wherein one method is to improve the electromagnetic attraction force through an electromagnetic coil, and the other method is to reduce the electromagnetic repulsion force. The electromagnetic force cannot be increased without limit because of the operational requirements of the product structure and the electrical life. At present, some schemes are also provided, a magnetic conductive ring which is composed of an upper yoke and a lower armature and is used for resisting short-circuit current is additionally arranged at the position of a movable reed, when the short-circuit current flows through the movable reed, an annular magnetic field can be generated at the periphery of the movable reed, the upper yoke and the lower armature can generate suction, the magnetic conductive ring composed of the upper yoke and the lower armature can form suction in a contact pressure direction to the movable reed, so that a movable contact and a static contact cannot bounce, the structure can gradually saturate electromagnetism along with the increase of the current, the short-circuit resistance can be improved to a certain degree, and the promotion is very limited.

The arc extinguishing of direct current contactor adopts the magnetic blow-out arc extinguishing usually, places the magnet steel around the sound contact promptly, though the magnet steel is favorable to direct current contactor arc extinguishing, extension electricity life, but a lot of schemes are difficult to effectively improve the arc extinguishing ability, and especially in the aspect of nonpolarity arc extinguishing, many magnet steel designs and places the scheme not very effective.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a short-circuit-resistant direct current contactor aiming at the defects in the prior art, wherein a short-circuit-resistant electromagnetic mechanism can generate a larger electromagnetic force for counteracting the electromagnetic repulsion between a moving contact and a static contact, so that the short-circuit resistance of a product is greatly improved, and the short-circuit resistance can reach the level of 20kA at most by using the scheme; through the structure of design arc extinguishing magnet steel and position, not only can improve the arc extinguishing ability of product, can also promote direct current contactor's nonpolarity arc extinguishing ability.

The invention adopts the following technical scheme:

a direct current contactor based on short circuit resistance comprises an upper supporting plate and a lower supporting plate, wherein two static contacts are arranged on the upper supporting plate, a lower magnetic yoke is arranged between the upper supporting plate and the lower supporting plate, the upper part of the lower magnetic yoke is connected with the upper supporting plate through an upper armature, a flat movable contact is arranged in the lower magnetic yoke, two ends of the flat movable contact extend out of the outer side of the lower magnetic yoke and are respectively connected with the corresponding static contacts, a final pressure spring is arranged between the lower side of the flat movable contact and the lower magnetic yoke, a movable iron core is arranged on the lower side of the lower supporting plate, and the movable iron core is connected with the lower magnetic yoke through a lower magnetic yoke connecting rod; and a group of magnetic steel sheets are respectively arranged on two sides of the joint of the flat movable contact and the corresponding fixed contact.

Specifically, the upper supporting plate is connected with the upper side of the upper armature through an upper armature connecting rod, the lower side of the upper armature is movably connected with the top of the lower magnetic yoke, the center of the flat movable contact is connected with one end of a final pressure spring, the other end of the final pressure spring is connected with the bottom of the lower magnetic yoke, and two ends of the flat movable contact are respectively connected with leading-out ends of the static contacts.

Furthermore, the upper armature is of a trapezoidal structure, the upper part of the lower magnetic yoke is provided with a notch corresponding to the trapezoidal structure, and the upper armature is arranged in the notch to realize magnetic conduction.

Furthermore, one end of the lower magnetic yoke connecting rod is connected with the lower part of the lower magnetic yoke, and the other end of the lower magnetic yoke connecting rod penetrates through the lower supporting plate and is arranged in the moving iron core.

Specifically, the upper armature is connected with the upper supporting plate through an upper armature connecting rod, the lower magnetic yoke comprises an upper cavity and a lower cavity, the flat movable contact is arranged in the upper cavity, two ends of the flat movable contact are respectively contacted with the leading-out ends of the static contacts when being closed, the final pressure spring is arranged in the lower cavity, and the bottom of the final pressure spring is connected with one end of the lower magnetic yoke connecting rod.

Furthermore, the upper part of the lower magnetic yoke is of an inclined plane structure, and the upper armature is obliquely arranged above the inclined plane structure of the lower magnetic yoke.

Furthermore, the upper armature and the upper armature connecting rod are fixedly connected or movably connected through a rotating shaft, and a reset device is arranged at the joint of the rotating shaft and the upper armature.

Furthermore, the reset device comprises a torsion spring or a reset reed, the torsion spring is arranged at the rotating shaft, and the reset reed is arranged at the center of the upper armature.

Furthermore, a lower magnet yoke connecting block is arranged on the lower supporting plate, a lower magnet yoke is arranged on the lower magnet yoke connecting block, and the other end of the lower magnet yoke connecting rod penetrates through the lower magnet yoke connecting block and the lower supporting plate and then is arranged in the moving iron core.

Specifically, the U-shaped magnetic yokes are correspondingly arranged outside each group of magnetic steel sheets, the magnetic steel sheets are connected with the U-shaped magnetic yokes in an adsorption mode, and the inner sides of each group of magnetic steel sheets are placed according to the N-N or S-S mode.

Compared with the prior art, the invention has at least the following beneficial effects:

the direct current contactor based on short circuit resistance adopts common parts such as an upper armature, a lower magnetic yoke, a flat plate movable contact and the like, and is low in cost; when a large current passes through the conductive loop, the flat moving contact, the upper armature and the lower magnetic yoke form a magnetic loop, the upper armature is subjected to the electromagnetic attraction of the lower magnetic yoke, and the electromagnetic attraction of the upper armature to the lower magnetic yoke is larger along with the increase of the current under the condition that the upper armature or the lower magnetic yoke is not changed, so that the electromagnetic repulsion between the moving contact and the fixed contact can be counteracted, and the short-circuit resistance is improved; a novel magnetic steel sheet placing mode is adopted, and magnetic steel sheets with N-N and S-S polarities are placed outside the moving contact and the static contact, so that the arc extinguishing capacity is improved, the non-polarity capacity of the direct current contactor can be improved, and the core competitiveness of a product is improved.

Furthermore, the upper armature is arranged on the upper portion of the lower magnetic yoke and movably connected with the lower magnetic yoke, and the purpose is that when a large short-circuit current (for example, several kA) passes through, a large Holm repulsive force is generated at a contact surface between the flat moving contact and the static contact to urge the flat moving contact and the static contact to separate, a magnetic loop is formed between the upper armature and the lower magnetic yoke by the current of the flat moving contact, a V-shaped interface is arranged between the upper armature and the lower magnetic yoke, the upper armature and the lower magnetic yoke are urged to be attached together due to the closing characteristic of the magnetic loop, and the upper armature is fixed, so that the lower magnetic yoke connected with the flat moving contact is subjected to the electromagnetic attraction of the upper armature, and the moving contact and the static contact can be kept not to be repelled, and the short-circuit resistance is improved.

Furthermore, the upper armature is of a trapezoid structure, the upper portion of the lower magnetic yoke is opened with a notch corresponding to the trapezoid structure, when a large short-circuit current flows, the trapezoid upper armature and the lower magnetic yoke form a magnetic loop, an oblique opening structure of the upper armature and the lower magnetic yoke can generate electromagnetic suction, and the lower magnetic yoke can generate upward suction for fixing the upper armature and the lower magnetic yoke to offset Holm repulsion between the moving contact and the static contact, so that the short-circuit resistance is improved.

Further, the one end of lower yoke connecting rod and the sub-unit connection of lower yoke, the other end run through the purpose or the benefit that the bottom suspension fagging setting set up in moving the iron core, and the coil can direct action in lower yoke to the electromagnetic suction who moves the iron core, and the yoke atress is more high-efficient.

Furthermore, the upper armature connection is connected with the upper support plate through an upper armature connecting rod, the lower magnetic yoke comprises an upper cavity and a lower cavity, the flat movable contact is arranged in the upper cavity, two ends of the flat movable contact are respectively contacted with leading-out ends of the static contacts when the flat movable contact is closed, the final pressure spring is arranged in the lower cavity, the bottom of the final pressure spring is connected with one end of the lower magnetic yoke connecting rod, the upper armature is connected with the upper support plate which is fixed in structure more stably, the flat movable contact is connected with the lower magnetic yoke in a constrained mode through the spring, when the movable contact and the static contact are contacted, the spring can provide final pressure for the contact for closing and reducing Holm force, and meanwhile, the lower magnetic yoke has a limiting and constraining effect on the flat movable contact.

Furthermore, the upper part of the lower magnetic yoke is of an inclined surface structure, and the purpose of the inclined surface structure is to generate electromagnetic attraction in a magnetic loop so as to promote the magnetic yoke to be attracted by the upper armature.

Furthermore, the upper armature is fixedly connected or rotatably connected with the upper supporting piece through a structural part, wherein a resetting device is required to be installed on the rotary connection of the clapper type structure to provide resetting force or counter force for the upper armature.

Further, the purpose of adjusting the elasticity coefficient of the torsion spring or the size of the spring is to adjust the attraction force between the upper armature and the lower magnetic yoke, so that different short circuit resistance is provided.

Further, the lower magnet yoke is arranged on the lower magnet yoke connecting block, and the other end of the lower magnet yoke connecting rod penetrates through the lower magnet yoke connecting block and the lower supporting plate and then is arranged in the movable iron core, so that the requirements of the installation and the fixed manufacturing process are met.

Furthermore, the U-shaped magnetic yoke is easy to mount or fix outside the ceramic cavity, and the U-shaped magnetic yoke can connect the magnetic fields of the two permanent magnets to reinforce each other.

In summary, the invention provides the lower magnetic yoke with the attraction force by the electromagnetic attraction force generated by the magnetic loop designed based on the electromagnetic principle, and is used for offsetting the Holm repulsion force generated by the moving contact and the static contact, the direct-acting release has simple method, and can adjust the electromagnetic attraction force between the upper armature iron and the magnetic yoke by adjusting the size and the inclined plane angle of the upper armature iron, and the clapper-type upper armature iron can adjust the electromagnetic attraction force between the clapper-type upper armature iron and the lower magnetic yoke by adjusting the inclined plane angle and the counter-force torsion spring (reed), so that the short-circuit resistance can be adjusted, and the manufacturing and process method is feasible, and is a scheme with high innovation.

The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.

Drawings

FIG. 1 is a partially constructed perspective view of embodiment 1 of the present invention;

FIG. 2 is a front view of a partial configuration of embodiment 1 of the present invention;

FIG. 3 is a cross-sectional view taken along plane A-A of FIG. 2;

fig. 4 is a schematic diagram showing the matching of the upper armature, the lower yoke, the flat movable contact and the like in embodiment 1 of the present invention;

fig. 5 is a schematic view of the distribution of magnetic flux when the upper armature, the lower yoke and the flat movable contact of embodiment 1 of the present invention are energized;

FIG. 6 is a partially constructed perspective view of embodiment 2 of the present invention;

FIG. 7 is a front view of a partial configuration of embodiment 2 of the present invention;

FIG. 8 is a cross-sectional view taken along plane A-A of FIG. 7;

fig. 9 is a schematic diagram showing the matching of the upper armature, the lower yoke, the flat movable contact and the like in embodiment 2 of the present invention;

fig. 10 is a schematic view showing the distribution of magnetic flux when the upper armature, the lower yoke and the flat movable contact of embodiment 2 of the present invention are energized;

fig. 11 is a schematic view of the magnetic steel and the U-shaped yoke according to embodiments 1 and 2 of the present invention;

fig. 12 is a schematic view of the position arrangement and magnetic field distribution of magnetic steel according to embodiments 1 and 2 of the present invention;

fig. 13 is a schematic view of position arrangement and magnetic field distribution of another magnetic steel according to embodiments 1 and 2 of the present invention.

Wherein: 1. a stationary contact; 2. an upper support plate; 3. a magnetic steel sheet; 4. a flat movable contact; 51. an upper armature; 52. an upper armature connecting rod; 61. a lower magnetic yoke; 62. a lower magnetic yoke connecting block; 63. a lower yoke connecting rod; 7. a final pressure spring; 8. a lower support plate; 9. a movable iron core; a U-shaped yoke.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "one side", "one end", "one side", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be construed as limiting the present invention. In addition, in the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

It is also to be understood that the terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the specification of the present invention and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

Various structural schematics according to the disclosed embodiments of the invention are shown in the drawings. The figures are not drawn to scale, wherein certain details are exaggerated and possibly omitted for clarity of presentation. The shapes of various regions, layers and their relative sizes and positional relationships shown in the drawings are merely exemplary, and deviations may occur in practice due to manufacturing tolerances or technical limitations, and a person skilled in the art may additionally design regions/layers having different shapes, sizes, relative positions, according to actual needs.

The invention provides a direct current contactor based on short circuit resistance.A top armature is arranged on a top support, a bottom magnetic yoke moves up and down along with a moving contact, wherein the top armature and the bottom magnetic yoke are in complete contact when a moving contact and a static contact are closed, and two contact surfaces of the top armature and the bottom magnetic yoke form a certain included angle. When current passes through the electromagnetic system, the upper armature, the lower magnetic yoke and the flat plate moving contact form a closed loop electromagnetic system, and the larger the current passing through the flat plate moving contact is, the larger the attraction force between the armature and the magnetic yoke is. The invention can improve the electromagnetic force and eliminate the electromagnetic repulsion between partial movable and static contacts, thereby greatly improving the short-circuit resistance of the product, and the maximum short-circuit resistance current can reach 20kA level.

Referring to fig. 1, 2 and 3, the short-circuit resisting dc contactor according to the present invention includes: two stationary contacts 1, an upper supporting plate 2, two groups of magnetic steel sheets 3, a flat movable contact 4, an upper armature 51, an upper armature connecting rod 52, a lower magnetic yoke 61, a lower magnetic yoke connecting rod 63, a final pressure spring 7, a lower supporting plate 8 and a movable iron core 9.

The two static contacts 1 are respectively arranged on the upper supporting plate 2, leading-out ends of the two static contacts 1 are respectively correspondingly connected with two ends of the flat movable contact 4, the lower side of the upper supporting plate 2 is connected with an upper armature 51 through an upper armature connecting rod 52, the upper armature 51 is arranged on the upper part of a lower magnetic yoke 61 and is movably connected with the lower magnetic yoke 61, the flat movable contact 4 penetrates through the lower magnetic yoke 61, a final pressure spring 7 is arranged in the lower magnetic yoke 61 below the flat movable contact 4, two ends of the flat movable contact 4 extend out of the lower magnetic yoke 61 and are respectively connected with the leading-out ends of the corresponding static contacts 1, two outer sides of two ends of the flat movable contact 4 are respectively provided with a group of magnetic steel sheets 3, and one end of each group of magnetic steel sheets 3 is connected with the upper supporting plate 2; the lower part of the lower yoke 61 is connected with one end of a lower yoke connecting rod 63, and the other end of the lower yoke connecting rod 63 penetrates through the lower support plate 8 and is arranged in the movable iron core 9.

Referring to fig. 4, an upper armature 51 of the dc contactor is fixedly connected to the upper support plate 2 through an upper armature connecting rod 52, a notch is formed in an upper portion of a lower magnetic yoke 61, the upper armature 51 has a trapezoidal structure and can be arranged in the notch to be in contact with the lower magnetic yoke 61, a flat movable contact 4 is arranged in the lower magnetic yoke 61, the upper armature 51 is arranged above the flat movable contact 4, a final pressure spring 7 is arranged below the flat movable contact 4, one end of the final pressure spring 7 is connected to the flat movable contact 4, and the other end of the final pressure spring is connected to the lower magnetic yoke 61.

Referring to fig. 5, the flat moving contact 4 moves in cooperation with the lower yoke 61, the lower yoke connecting rod 63 and the final pressure spring 7; when rated current is conducted, the flat moving contact 4, the upper armature 51 and the lower magnetic yoke 61 form a closed conducting magnetic ring, when fault short-circuit current larger than or equal to 5kA is generated between the leading-out end of the static contact 1 and the flat moving contact 4, electromagnetic repulsion larger than or equal to 50N is generated at the contact position of the leading-out end of the static contact 1 and the flat moving contact 4, larger electromagnetic attraction can be generated between the upper armature 51 and the lower magnetic yoke 61 due to the structure of the magnetic conduction closed ring and the contact surface thereof, the electromagnetic repulsion between a part of static and dynamic contacts is eliminated and counteracted, the static and dynamic contacts are ensured to be closed and not to be bounced off by the electromagnetic repulsion, so the short-circuit resistance of the contactor is improved, and the maximum short-circuit resistance reaches 20 kA.

Referring to fig. 6 and 7, in a clapper structure according to a second embodiment of the present invention, when a large current is generated, a current flowing through the flat movable contact 4 forms a magnetic loop between the lower magnetic yoke 61 and the upper armature 51, the magnetic loop generates an electromagnetic attraction at the bevel structure and increases with the increase of the current until the magnetic field strength approaches saturation, the fixed upper armature 51 causes the lower magnetic yoke 61 to generate an attraction, and the attraction can counteract Holm repulsion generated between the movable and stationary contacts, thereby ensuring the attraction of the movable and stationary contacts and improving the short-circuit resistance.

Two static contacts 1 are respectively arranged on an upper supporting plate 2, leading-out ends of the two static contacts 1 are respectively correspondingly connected with two ends of a flat movable contact 4, the lower side of the upper supporting plate 2 is connected with an upper armature 51 through an upper armature connecting rod 52, the upper armature 51 is arranged on the upper part of a lower magnetic yoke 61, the flat movable contact 4 penetrates through the lower magnetic yoke 61, a final pressure spring 7 is arranged in the lower magnetic yoke 61 below the flat movable contact 4, and the final pressure spring 7 is connected with a movable iron core 9 through a lower magnetic yoke connecting rod 63.

Referring to fig. 8, the lower magnetic yoke 61 includes an upper cavity and a lower cavity, the flat movable contact 4 is disposed in the upper cavity, two ends of the flat movable contact 4 extend out of the lower magnetic yoke 61 and are respectively connected with the leading-out ends of the corresponding stationary contacts 1, two sides of the outer portions of two ends of the flat movable contact 4 are respectively provided with a set of magnetic steel sheets 3, and one end of each set of magnetic steel sheets 3 is connected with the upper support plate 2; the lower supporting plate 8 is provided with a lower magnetic yoke connecting block 62, the final pressure spring 7 is arranged in the lower cavity, the lower cavity is connected with one side of the lower supporting plate 8 through the lower magnetic yoke connecting block 62, the movable iron core 9 is arranged on the other side of the lower supporting plate 8, one end of a lower magnetic yoke connecting rod 63 is arranged in the movable iron core 9, and the other end of the lower magnetic yoke connecting rod is connected with the final pressure spring 7 after sequentially passing through the lower supporting plate 8 and the lower magnetic yoke connecting block 62.

Referring to fig. 9, one end of an upper armature 51 and one end of an upper armature link 52 are fixedly connected or movably connected through a rotation shaft, a torsion spring is installed at the rotation shaft or a return spring is installed at the center of the upper armature 51 for providing a return force of the upper armature, a contact surface of the upper armature 51 and a lower yoke 61 is an inclined surface, and the upper armature 52 is fixed on an upper bracket relatively stably, if the rotation shaft is connected, the electromagnetic attraction force of the upper armature and the lower yoke is adjustable, so that the short circuit resistance is adjusted.

Referring to fig. 10, the magnetic flux distribution is similar to that of fig. 5 in the attraction process, and there are two differences, one is that the two magnetic flux densities are different, fig. 5 is more dense and easily causes magnetic saturation, and the other is that the adjustable structure with the torsion spring of fig. 10 is more easily saturated at one side of the rotating shaft.

An upper armature 51 of the direct current contactor is fixedly connected with an upper supporting plate 2 through an upper armature connecting rod 52, and the flat moving contact 4 moves in a matching way along with a lower magnetic yoke 61, a lower magnetic yoke connecting rod 63 and a final pressure spring 7; when rated current is conducted, the flat moving contact 4, the upper armature 51 and the lower magnetic yoke 61 form a closed conducting magnetic ring, when fault short-circuit current which is more than or equal to 5kA is generated at the leading-out end 1 of the static contact and the flat moving contact 4, electromagnetic repulsion which is more than or equal to 50N is generated at the contact position of the leading-out end of the static contact 1 and the flat moving contact 4, electromagnetic attraction which is more than or equal to 20N is generated between the upper armature 51 and the lower magnetic yoke 61 due to the structure of the magnetic conduction closed ring and the contact surface of the magnetic conduction closed ring, so that the electromagnetic repulsion between a part of moving and static contacts is eliminated and counteracted, the moving and static contacts are ensured to be closed and not to be flicked by the electromagnetic repulsion, the short-circuit resistance of the contactor is improved, and the maximum short-circuit resistance reaches 20 kA.

The upper armature 52 and the lower yoke 61 are constructed of a ferromagnetic material, such as electrically pure iron DT 4.

The length, width, height and angle of the matching surfaces of the upper armature 52 and the lower magnetic yoke 61 are adjustable, for example: the inclined plane can be processed into 5-30 degrees (the included angle with the transverse plane of the lower magnetic yoke 61), the electromagnetic attraction between the upper armature 52 and the lower magnetic yoke 61 is different, and the Holm repulsion between the moving contact and the static contact is offset by the inclined plane and correspondingly changed, so that the short-circuit resistance of the direct current contactor is adjustable.

Referring to fig. 11, the dc contactor further includes a U-shaped yoke 10, two sets of magnetic steel sheets 3 are respectively attached to the corresponding U-shaped yoke 10, each set of magnetic steel sheets 3 is disposed at the leading-out end of the stationary contact 1 and the outer side of the flat movable contact 4, and the U-shaped yoke 10 is made of a ferromagnetic material.

Referring to fig. 12 and 13, the magnetic steel sheets of the dc contactor are made of permanent magnetic material, such as neodymium iron boron, each set of magnetic steel sheets is located at two sides of the stationary contact 1 and the flat moving contact 4, and each set of magnetic steel sheets 3 is placed according to the inner side N-N or S-S for realizing non-polar arc extinction.

In summary, for the scheme 1 for improving short circuit resistance, a direct-acting upper armature structure (contact inclined plane 45 degrees and width 1/2 of a lower yoke) is adopted, and compared with a scheme without short circuit resistance, experimental tests are carried out, wherein the short circuit resistance of the scheme 1 reaches 15kA, the short circuit resistance of the scheme without short circuit resistance is only 10kA, and the short circuit resistance is improved by 50%.

The above-mentioned contents are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modification made on the basis of the technical idea of the present invention falls within the protection scope of the claims of the present invention.

Claims (10)

1. The direct current contactor based on the short circuit resistance is characterized by comprising an upper supporting plate (2) and a lower supporting plate (8), wherein two fixed contacts (1) are arranged on the upper supporting plate (2), a lower magnetic yoke (61) is arranged between the upper supporting plate (2) and the lower supporting plate (8), the upper part of the lower magnetic yoke (61) is connected with the upper supporting plate (2) through an upper armature (51), a flat movable contact (4) is arranged in the lower magnetic yoke (61), two ends of the flat movable contact (4) extend out of the outer side of the lower magnetic yoke (61) and are respectively connected with the corresponding fixed contacts (1), a final pressure spring (7) is arranged between the lower side of the flat movable contact (4) and the lower magnetic yoke (61), a movable iron core (9) is arranged on the lower side of the lower supporting plate (8), and the movable iron core (9) is connected with the lower magnetic yoke (61) through a lower magnetic yoke connecting rod (63); two sides of the joint of the flat movable contact (4) and the corresponding fixed contact (1) are respectively provided with a group of magnetic steel sheets (3).

2. The direct current contactor based on short circuit resistance according to claim 1, characterized in that the upper supporting plate (2) is connected with the upper side of the upper armature (51) through an upper armature connecting rod (52), the lower side of the upper armature (51) is movably connected with the top of the lower yoke (61), the center of the flat moving contact (4) is connected with one end of the final pressure spring (7), the other end of the final pressure spring (7) is connected with the bottom of the lower yoke (61), and the two ends of the flat moving contact (4) are respectively connected with the leading-out ends of the fixed contact (1).

3. The direct current contactor based on short circuit resistance according to claim 2, characterized in that the upper armature (51) is of a trapezoidal structure, the upper part of the lower magnetic yoke (61) is provided with a notch corresponding to the trapezoidal structure, and the upper armature (51) is arranged in the notch to realize magnetic conduction.

4. The short-circuit resistant based direct current contactor according to claim 2, wherein one end of the lower yoke connecting rod (63) is connected with the lower portion of the lower yoke (61), and the other end is disposed in the movable iron core (9) through the lower supporting plate (8).

5. The direct current contactor based on short circuit resistance according to claim 1, wherein the upper armature (51) is connected with the upper supporting plate (2) through an upper armature connecting rod (52), the lower yoke (61) comprises an upper cavity and a lower cavity, the flat movable contact (4) is arranged in the upper cavity, two ends of the flat movable contact (4) are respectively contacted with the leading-out ends of the fixed contacts (1) when being closed, the final pressure spring (7) is arranged in the lower cavity, and the bottom of the final pressure spring (7) is connected with one end of a lower yoke connecting rod (63).

6. The short-circuit resistant based direct current contactor according to claim 5, wherein the upper portion of the lower yoke (61) is a slope structure, and the upper armature (51) is obliquely disposed above the slope structure of the lower yoke (61).

7. The direct current contactor based on short circuit resistance according to claim 5, characterized in that the upper armature (51) and the upper armature connecting rod (52) are fixedly connected or movably connected through a rotating shaft, and a reset device is arranged at the connection position of the rotating shaft and the upper armature (51).

8. The short-circuit resistant based direct current contactor according to claim 7, wherein the reset means comprises a torsion spring disposed at the rotation shaft or a reset reed disposed at the center of the upper armature (51).

9. The short-circuit-resistant-based direct current contactor according to claim 5, wherein a lower yoke connecting block (62) is arranged on the lower supporting plate (8), the lower yoke (61) is arranged on the lower yoke connecting block (62), and the other end of the lower yoke connecting rod (63) penetrates through the lower yoke connecting block (62) and the lower supporting plate (8) and is arranged in the movable iron core (9).

10. The direct current contactor based on short circuit resistance according to claim 1, wherein a U-shaped yoke (10) is correspondingly arranged on the outer portion of each group of magnetic steel sheets (3), the magnetic steel sheets (3) are connected with the U-shaped yoke (10) in an absorption mode, and the inner side of each group of magnetic steel sheets (3) is placed according to N-N or S-S.

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