CN107564764B - Arc extinguishing load switch - Google Patents

Abstract

The invention relates to the technology of power equipment, and particularly discloses an arc-extinguishing load switch which comprises a first conductive end, a second conductive end and a conductive rod driven to reciprocate, wherein the conductive rod moves to realize closing and opening. The second conductive end comprises a piston and a second contact; the second contact is arranged outside the piston, and a gap is formed between the second contact and the piston; the conducting rod is a hollow cavity, is arranged in the gap and accommodates the piston in the cavity; the second contact and the conducting rod can keep electric connection in the moving process; the cavity of the conducting rod and the piston form a variable-volume gas accommodating space; the first conductive end includes a first contact; the end part of the conducting rod is provided with an airflow nozzle and an air generating element which are communicated with the air containing space. When the brake is opened, the conducting rod moves downwards to reduce the gas containing space and generate high-pressure airflow so as to extinguish electric arcs generated by the opening; meanwhile, the gas generating element at the end part of the conducting rod releases arc extinguishing gas under the action of the electric arc, so that the electric arc is extinguished.

Description

Arc extinguishing load switch

Technical Field

The invention relates to the technology of power equipment, in particular to an arc-extinguishing load switch with two arc-extinguishing modes of air-compressing arc-extinguishing and gas-producing arc-extinguishing.

Background

When the switching electric appliance is used for cutting off current, if the circuit voltage is higher than 10-20 volts and the current is higher than 80-100 mA, electric arcs can be generated between contacts of the electric appliance. The arc is a strong and durable gas discharge phenomenon generated between two electrodes, is high-temperature and high-conductivity free gas essentially, and not only has great damage effect on a contact, but also prolongs the time for breaking a circuit.

12kV medium-voltage load switch equipment on the market at present mainly has 5 modes: oil immersion type, gas compression type, gas generation type, SF6 (sulfur hexafluoride) gas type, and vacuum type. Although the vacuum structure is convenient, the technology is disclosed in the invention patent document of China's grant publication No. CN 101800137B, but the cost is high and no fracture is isolated; SF6 gas has relatively superior performance, such as the technology disclosed in the invention patent document of Chinese publication No. CN 101425421A, but SF6 gas is a non-environmental-friendly gas, and the development and application of the gas are limited; the traditional air compression type and gas production type products are influenced by arc extinguishing performance, have very large volume and cannot realize miniaturization, and for example, the utility model patent document of the Chinese patent publication CN 2256584Y discloses a safe air compression type air load switch. In summary, most of the existing load switches are used independently to perform arc extinction in the above way, and the related arc extinction structures cannot be combined skillfully and organically, so that the overall structure is clumsy; therefore, the arc extinguishing capability of the existing arc extinguishing switch needs to be further improved, and the structure needs to be further optimized.

In addition, the existing designs aiming at the gas compression type structure and the gas production type structure are relatively rough, and the design aiming at the arc extinguishing structure and the gas flow structure for refining is not provided, so the arc extinguishing performance is poor, the miniaturization cannot be realized, and the cost is reduced.

Disclosure of Invention

The invention aims to provide an arc-extinguishing load switch structure which skillfully combines a gas-compression type arc-extinguishing structure and a gas-production type arc-extinguishing structure, so that the arc-extinguishing performance is improved, and the cost is reduced.

A second object of the present invention is to provide an arc quenching load switch with an optimized arcing contact structure, which improves the current transfer capability when breaking current.

A third object of the present invention is to provide an arc extinguishing load switch with an optimized nozzle structure, which can optimize the airflow field and enhance the arc extinguishing capability.

In order to achieve the purpose, the invention adopts the following technical scheme:

an arc extinguishing load switch comprises a first conducting end, a second conducting end and a conducting rod capable of being driven to reciprocate, and switching on or switching off of the first conducting end and the second conducting end is realized through the reciprocating motion of the conducting rod;

the first conductive end comprises a first contact, and the conductive rod can be in conductive connection with the first contact when moving towards and approaching the first conductive end;

the second conductive end comprises a piston and a second contact; the second contact is arranged beside the piston, and a gap is formed between the second contact and the piston;

the conducting rod is of a hollow structure with a cavity; the conducting rod is arranged in the gap, the piston is accommodated in the cavity, the second contact is contacted with the outer surface of the conducting rod, and the second contact is always electrically connected with the conducting rod in the motion process; the piston and the cavity form a gas containing space with variable volume;

the conductive rod comprises a first end facing the first conductive end and a second end facing the second conductive end; wherein the first end of the conducting rod is provided with an airflow nozzle communicated with the gas containing space and a gas generating element;

the conducting rod moves towards the direction close to the first conducting end to be in conducting connection with the first conducting end, a closing state is achieved, and at the moment, the volume of the gas containing space is increased and gas is sucked;

the conducting rod moves towards the direction far away from the first conducting end to be separated from the first conducting end, the switching-off state is achieved, the gas generating element receives arc energy generated when the conducting rod is separated from the first contact, and arc extinguishing gas is released to extinguish the arc; and meanwhile, the volume of the gas containing space is reduced to generate high-pressure gas flow, and the high-pressure gas flow is sprayed out from the gas flow nozzle to extinguish the electric arc.

In a possible embodiment of the present invention, the air flow nozzle includes a hollow cavity and a nozzle head, and the nozzle head is disposed on the top of the air flow nozzle and is used for ejecting air flow; the gas flow nozzle is coupled at a bottom thereof to the first end of the conductive rod, and the cavity is interposed between the top and the bottom of the gas flow nozzle.

In a preferred embodiment of the present invention, the gas generating element is disposed in the cavity of the gas flow nozzle, so as to not only prevent the generated arc extinguishing gas from leaking into the environment, but also utilize the kinetic energy of the compressed gas to impact the arc at a certain speed, thereby having a high arc extinguishing capability.

In a possible embodiment of the present invention, the first conductive end further includes a first contact block and a static arcing contact, and both the first contact and the static arcing contact are fixed and electrically connected to the first contact block; the end of the static arcing contact is closer to the conductive rod than the first contact; and the first end of the conducting rod is also provided with a movable arc striking contact which is in fit connection with the static arc striking contact, and the movable arc striking contact is in conductive connection with the conducting rod.

In a possible embodiment of the present invention, the movable arcing contact includes a movable arcing contact body and a plurality of petal-shaped elastic contact pieces extending perpendicularly from the movable arcing contact body; the movable arcing contact body is electrically connected with the conducting rod; the petal-shaped contact pieces form a ring shape and can surround the outside of the static arcing contact, so that the static arcing contact and the movable arcing contact are still in conductive connection at the moment of switching off, current is transferred from an arc contact loop to a conductive loop formed by the first contact and the second contact, and the current transfer capacity is improved.

In a possible embodiment of the invention, the movable ignition arc contact is located at the bottom of the cavity of the gas flow nozzle, and the gas generating element is arranged between the nozzle head of the gas flow nozzle and the movable ignition arc contact. Therefore, the gas generating element can receive most of the arc energy, and the generated arc extinguishing gas can obtain the initial speed to the maximum extent, thereby improving the efficiency of the gas generating element for utilizing the arc energy and generating more arc extinguishing gas more quickly.

In a feasible embodiment of the invention, the gas generating element is a gas generating ring made of a gas generating material, and the gas generating ring is sleeved outside the petal-shaped contact piece of the movable ignition arc contact so as to effectively fix the gas generating element.

In a feasible embodiment of the invention, the movable striking arc contact body is provided with a plurality of through holes, and the positions of the through holes are centered on the petal-shaped contact piece to form central symmetry.

In a possible embodiment of the present invention, the air flow nozzle further includes a throat portion located below the nozzle head for connecting the cavity, and the throat portion is provided with at least one air flow guide groove, so that the air flow sprayed from the nozzle head has a spiral effect. Preferably, the air flow guide is a circular, continuous spiral or discrete spiral line segment.

In a feasible embodiment of the invention, the inner wall of the cavity of the airflow nozzle is provided with an inclined plane at a position connected to the lower part of the nozzle head, the inclined plane is distributed in an inverted splayed manner at two sides of the nozzle head, and the inclined plane and the axial direction of the conducting rod form an included angle smaller than or equal to 90 degrees; preferably 40-80.

In a possible embodiment of the present invention, the piston is disposed at one end of a piston rod, and the other end of the piston rod is fixed to the piston rod base.

In a possible embodiment of the present invention, the second contact and/or the first contact is a ring-shaped conductive contact having an inward elastic force, the second contact is disposed outside the piston, and the second contact forms the gap with the piston; the second contact surrounds the outside of the conducting rod by means of inward elastic force of the second contact, so that the conducting rod is always in conductive connection with the second contact in the reciprocating movement process; the first contact achieves conductive connection with the conductive rod which is continuously close to the first contact by virtue of the inward elastic force of the first contact, and has the effect of grasping the conductive rod to form reliable conductive connection.

In a possible embodiment of the invention, the second contact and the first contact are a tulip contact, an annular spring contact finger or a conductive ring sleeve comprising a plurality of longitudinally extending claws.

In a feasible embodiment of the invention, the outside of the conducting rod is connected with a crank arm, and the crank arm drives the conducting rod to move up and down so as to realize switching on and switching off.

In a possible embodiment of the present invention, the second conductive end further includes an insulating base, and the second contact block is fixed on the insulating base.

In a possible embodiment of the present invention, the first conductive end further includes an insulating base, and the first contact block is fixed on the insulating base.

In a possible embodiment of the invention, the gas generating element or the gas generating ring is made of polytetrafluoroethylene or a polytetrafluoroethylene mixture.

The beneficial technical effects of the invention comprise:

the invention utilizes the ingenious structure, the conducting rod is used as a moving contact, and simultaneously, the hollow cavity body of the conducting rod moves relative to the piston rod to form high-pressure airflow to be sprayed out to play an arc extinguishing role; the gas generating element is arranged at the first end (movable contact end) of the conducting rod, and the high-temperature and high-heat action of the electric arc is fully utilized to enable the gas generating element to generate gas, so that the gas generating and arc extinguishing effects are achieved. In the invention, the conducting rod moves between the first conducting end and the second conducting end; the conducting rod has a long length, and the whole inner cavity of the conducting rod is completely hollow, so that the variable volume of the gas accommodating space has a wide threshold range, and favorable basic conditions can be provided for forming higher-pressure and higher-speed arc extinguishing gas flows. The invention has simple integral structure, combines the air-compressing arc-extinguishing structure and the gas-generating arc-extinguishing structure organically and skillfully, not only improves the arc-extinguishing efficiency, but also reduces the cost and is beneficial to realizing the miniaturization of products.

In addition, the invention also has an airflow nozzle with a hollow cavity structure, and the gas generating element is arranged in the cavity and is arranged close to the movable striking arc contact, so that the arc energy can be utilized to the maximum extent, the gas generating capability and the utilization efficiency are improved, the generated arc extinguishing gas is sprayed to the root part of the arc along with the high-speed and high-pressure airflow, and the arc extinguishing capability is improved.

Moreover, the invention also specially improves the cavity and the throat part of the airflow nozzle, and optimizes the performance of the airflow field; the invention further optimizes the matching structure of the movable arcing contact and the static arcing contact, and is beneficial to transferring the current from the conducting end loop to the arcing contact loop at the moment of breaking the current.

The first contact and the second contact are ring-shaped conductive contacts with inward elastic force, and can form a conductive loop which can be electrically connected in flexible movement.

Drawings

FIG. 1 is a cross-sectional view of an arcing load switch in a closed position in accordance with a first embodiment of the present invention;

FIG. 2 is a cross-sectional view of the embodiment of FIG. 1 with the quenching load switch in the tripped position;

FIG. 3 is a schematic diagram of the switch of FIG. 1 with the conductive rod separated from the second conductive end;

FIG. 4 is an enlarged schematic view of a second preferred embodiment of the present invention showing a switch gas flow nozzle and a movable arcing contact;

fig. 5A is a schematic cross-sectional view of a movable arcing contact of a switch according to a second preferred embodiment of the present invention.

Fig. 5B is a top view of a movable arcing contact of a switch according to a second preferred embodiment of the present invention.

Description of symbol notation:

the gas-insulated switch comprises a first conductive end 11, a first contact seat 112, a first contact 111, a first conductive end insulating base 113, a static arc striking contact 114, a second conductive end 13, a second contact seat 132, a second contact 131, a second conductive end insulating base 133, a piston rod 134, a ring groove 1341, a sealing ring 1342, a piston rod base 135, a crank arm 14, a conductive rod 12, a conductive rod first end 121, a conductive rod second end 122, a conductive rod cavity 123, a gas containing space V, a gas flow nozzle 15, a gas flow nozzle cavity 151, a nozzle tip 152, a throat 153, a gas flow guide groove 1531, a cavity inner wall 1511, an inclined plane 1512, an included angle 1513, a dynamic arc striking contact 16, a dynamic arc striking contact body 161, a contact piece 162 of the dynamic arc striking contact, a through hole 1611 and a gas generating element 17.

Detailed Description

Exemplary embodiments that embody features and advantages of the invention are described in detail below. It is to be understood that the invention is capable of other and different embodiments and its several details are capable of modification without departing from the scope of the invention, and that the description and drawings are to be regarded as illustrative in nature and not as restrictive.

Example one

FIG. 1 is a cross-sectional view of an arcing load switch in a closed position in accordance with a first embodiment of the present invention; FIG. 2 is a cross-sectional view of the embodiment of FIG. 1 with the quenching load switch in the tripped position; fig. 3 is a schematic structural diagram illustrating a state in which a conductive rod of the switch of the embodiment shown in fig. 1 is separated from a second conductive end.

As shown in fig. 1-3, the quenching load switch includes a first conductive terminal 11, a second conductive terminal 13 (see fig. 3), and a conductive rod 12 driven to move. Through the movement of the conductive rod 12, the first conductive end 11 and the second conductive end 13 can be electrically connected or disconnected, so as to implement the switching on and off operations of the switch.

Wherein fig. 1 illustrates a closing state, the first end 121 of the conductive rod 12 is in conductive contact with the first contact 111 of the first conductive end 11, and the second end 122 of the conductive rod 12 is in conductive contact with the second contact 131 of the second conductive end 13; fig. 2 illustrates the open state, the first end 121 of the conductive rod 12 is away from the first contact 111 of the first conductive end 11, and the first conductive end 11 and the second conductive end 13 are already in the open state, although the second contact 131 of the second conductive end 13 is still in conductive contact with the second end 122 of the conductive rod 12.

As shown in fig. 1 and fig. 3, the second conductive terminal 13 includes a second conductive terminal insulating base 133, a second contact seat 132 fixed on the second conductive terminal insulating base 133, a second contact 131, and a piston rod 134 for fixing a piston rod base 135 of the piston rod 134.

The second end of the piston rod 134 is fixed on a piston rod base 135 with insulating property and is arranged in a vertical direction, the first end of the piston rod 134 is provided with an annular groove 1341, a sealing ring 1342 is filled in the annular groove 1341, the first end of the piston rod 134 cooperates with the sealing ring 1342 to form a piston, and the piston is arranged in a cavity of the conductive rod.

In this embodiment, the second conductive terminal insulating base 133, the second contact seat 132, and the second contact 131 have a hole therebetween for the piston rod 134 to pass through; in other words, the second conductive terminal insulating base 133, the second contact seat 132 and the second contact 131 are annularly arranged outside the piston rod 134, and have a hole in the middle for the piston rod 134 to pass through. Wherein the second contact 131 is preferably a ring-shaped conductive contact having an inward elastic force, such as a tulip contact; the plum blossom contact piece is a ring formed by a plurality of metal conducting strips with gaps, and the periphery of the ring is provided with a spring ring for binding. The spring force of the spring ring keeps the second contact 131 with inward spring force all the time, and the second contact can surround the outside of the rod-shaped conductive member by the spring force to form reliable conductive connection. As shown in fig. 3, one end of the second contact 131 surrounds the outside of the second contact seat 132 under the action of the spring force, and forms a reliable electrical connection and mutual fixation therewith; the other end of the second contact 131 can be encircled outside the other rod-shaped conductive member to form a reliable electrical connection. As shown in fig. 3, the second contact 131 is disposed around the outside of the piston rod 134, and a gap is formed between the two, and the gap is just for inserting one conductive rod 12 therebetween, at this time, the outer wall of the second end 122 of the conductive rod 12 is surrounded by the second contact 131 and is electrically connected.

With reference to the structures shown in fig. 1 to 3, the conductive rod 12 is a hollow tubular metal member having a cavity 123, and the conductive rod 12 is conductive. The chamber 123 may store air. The conducting rod 12 is sleeved outside the piston rod 134, and the sealing ring 1342 on the piston rod 134 can be in close contact with the inner wall surface of the conducting rod cavity 123, so as to achieve a sealing effect, and a portion of the cavity 123 above the piston rod 134 forms a gas accommodating space V with a variable volume. In other words, the end of the piston rod 134 with the seal 1342 in fact constitutes a first piston structure, which is received in the cavity 123 and is available for sealing and compressing the gas.

The outside of the conductive rod 12 is connected with a crank arm 14, the crank arm 14 is an operation end for opening or closing, the crank arm 14 drives the conductive rod 12 to move up and down, and in the moving process of the conductive rod 12, the conductive rod slides relative to the second contact 131, but because the second contact 131 is a conductive ring sleeve with inward elastic force, the second contact 131 can tightly lean against the outside of the conductive rod 12 by virtue of the inward elastic force, so that in the moving process of the conductive rod 12, the second contact 131 is still in conductive connection with the conductive rod 12, and flexible moving connection is realized.

Referring to fig. 2 and 3, a gas flow nozzle 15 and a gas generating element 17 are disposed at the first end 121 of the conductive rod 12, specifically, at the first end of the conductive rod 12. The gas flow nozzle 15 comprises a cavity 151 and a nozzle tip 152, the cavity 151 is located at the lower part of the gas flow nozzle 15 and can temporarily store a certain amount of accumulated gas, and the gas flow nozzle also comprises arc extinguishing gas generated by the gas generating element 17. The bottom of the gas flow nozzle 15 is fixedly connected with the first end 121 of the conducting rod 12 and is in gas communication with the gas accommodating space V. The nozzle tip 152 is disposed on the top of the air flow nozzle 15 and extends upward for a certain length for jetting high-speed air flow under pressure. The gas generating element 17 is a solid element made of a material capable of releasing arc extinguishing gas under the action of high temperature and high heat. Preferably, the gas generating element 17 is disposed within the cavity 151 of the gas flow nozzle 15. The purpose of the design is that high temperature and high heat brought by the electric arc generated by the opening enable the surface of the gas generating element 17 to be gasified and release arc extinguishing gas, the arc extinguishing gas is temporarily stored in the cavity 151 and is sprayed out from the nozzle 152 of the gas flow nozzle 15 by the high-pressure and high-speed air flow rushing belt extruded from the cavity 123 of the conducting rod inner cavity, and the arc extinguishing efficiency is improved. Therefore, the gas generating element 17 is disposed inside the cavity 151 of the gas flow nozzle 15, and the gas generating capability and the utilization efficiency can be improved to the greatest extent. For example, the gas generating element 17 is selected to be a solid element that can be made of polytetrafluoroethylene or a mixture of polytetrafluoroethylene.

A moving ignition contact 16 is also fixedly coupled to the end of the first end 121 of the conductive rod 12. As shown in fig. 3, the movable arcing contact 16 is also optionally disposed in the cavity 151 of the air flow nozzle 15, and the movable arcing contact 16 includes a movable arcing contact body 161 and a contact piece 162, wherein the contact piece 162 faces below the nozzle tip 152, so that the stationary arcing contact 114 of the upper contact holder 11 can be brought into conductive contact with the contact piece 162 after entering through a through hole in the nozzle tip 152. The contact piece 162 automatic arc striking contact body 161 extends vertically to form a cylindrical structure, the gas generating element 17 is a gas generating ring which is sleeved outside the contact piece 162, and an axial through hole is arranged in the middle of the gas generating ring, and the through hole not only can be used for smoothly spraying gas in the gas accommodating space V, but also can be used for enabling the static arc striking contact 114 to pass through. The gas generating ring is preferably spaced from the contact 162 by a distance that facilitates the smooth release of gas generated by the gas generating ring.

With reference to fig. 1 and 2, the structure of the upper conductive seat 11 is schematically illustrated. The first conductive terminal 11 includes a first conductive terminal insulating base 113, a first contact block 112 is fixed on the insulating base 113, and the cross section of the first contact block 112 is substantially "Jiong". The first contact 111 is preferably a loop-shaped conductive contact having an inward spring force, such as a tulip contact; the plum blossom contact piece is a ring formed by a plurality of metal conducting strips with gaps, and the periphery of the ring is provided with a spring ring for binding. Therefore, the first contact 111 always keeps inward elastic force, so that the first contact can surround the outside of a rod-shaped conductive piece to form reliable conductive connection. Wherein one end of the first contact 111 is tightly-hooped outside the first contact block 112 and is electrically connected. The second end of the first contact 111 extends downward, and a butt space into which the conductive rod 12 extends is formed inside the second end of the first contact 111. The first contact block 112 is further fixedly provided with a static arcing contact 114, the static arcing contact 114 is arranged on the inner side of the first contact 111, and the static arcing contact 114 is lower than the second end of the first contact 111 (closer to the conductive rod 12). The stationary arcing contact 114 is fixedly and conductively coupled to the first contact block 112 to form an arc extinguishing circuit. The static arcing contact 114 may extend from the tip 152 of the air flow nozzle 15 at the first end of the conductor bar 12 to connect with the contact piece 162 of the dynamic arcing contact located below the tip 152.

The switching-on process of the arc extinguishing load switch 100 is as follows: the switch mediates the switch-on indication, the crank arm 14 is operated to drive the conducting rod 12 to move upwards, and at the moment, the volume of the gas containing space V is gradually increased and air is continuously sucked from the nozzle 152; as the conductive rod 12 enters the abutting space at the inner side below the first contact 111, the first contact 111 tightly embraces the outer wall of the conductive rod 12 with its inward elastic force to form a reliable conductive connection until the conductive rod 12 moves up to the maximum stroke, at which time the volume of the gas accommodating space V is at the maximum (e.g. Vmax in fig. 1). At the same time, the static arcing contact 114 of the first contact block 112 penetrates from the nozzle tip 152 of the air flow nozzle 15 at the first end of the conductive rod 12 to be conductively connected with the contact piece 162 of the dynamic arcing contact.

The switching-off process of the arc extinguishing load switch 100 is as follows: when the switch receives the opening indication, the operating crank arm 14 drives the conductive rod 12 to move downward (indicated by the arrow on the right side of fig. 2), at this time, since the piston rod 134 is stationary (the piston rod 134 plays a role of compressing the gas and guiding the conductive rod 12 to move linearly), and the sealing ring 1342 at the first end of the piston rod 134 is sealed with the inner wall of the cavity 123 of the conductive rod 12, the gas containing space V is continuously reduced (e.g., Vmin of fig. 2), and high-speed high-pressure gas is formed to extinguish the generated arc. Meanwhile, the gas generating element 17 disposed in the cavity 151 of the gas flow nozzle 15 is affected by the high temperature and high heat energy of the switching-off arc, and the surface of the gas generating element is gasified to generate a large amount of arc extinguishing gas, which is firstly accumulated and temporarily stored in the cavity 151 (to prevent the gas from leaking out and polluting the environment), and then rushes towards the arc along with the air extruded from the gas accommodating space V, so as to improve the arc extinguishing capability.

Wherein, the gas generating element 17 is a gas generating ring sleeved outside the contact piece 162 of the movable ignition contact, so that the gas generating ring element can be replaced as required as the service time of the switch is prolonged. The gas generating ring is positioned in the cavity 151 and between the nozzle tip 152 of the gas flow nozzle and the movable arcing contact 16, so that the leakage of arc extinguishing gas generated at high temperature is avoided, the impact effect of kinetic energy of air extruded from the gas containing space V can be obtained to the maximum extent, and a larger initial speed is obtained. The static arcing contact 114 is closer to the conducting rod 12 than the first contact 111, so that during opening, the conducting rod 12 and the first contact 111 are firstly disconnected, and the static arcing contact 114 and the dynamic arcing contact 16 are secondly disconnected; therefore, at the stage of starting to open, a large amount of current can be concentrated on the loop of the static arcing contact 114 and the dynamic arcing contact 16, and then the static arcing contact 114 is disconnected with the dynamic arcing contact 16, so that the strong arc can be concentrated near the dynamic arcing contact 16, and therefore, the gas generating element 17 is sleeved outside the contact piece 162 of the dynamic arcing contact 16, the arc energy can be utilized to the maximum extent, and the gas generating efficiency and the utilization efficiency are improved.

In the present embodiment, the maximum moving stroke of the conductive rod 12 can be set to 140mm, which can meet the design requirement of miniaturization. In the processes of closing, opening, air compression arc extinguishing and gas production arc extinguishing, the only moving part is the conducting rod 12, and the actions of opening, arc striking and arc extinguishing can be completed only by one downward moving process of the conducting rod 12. Compared with the prior art, the arc extinguishing functional component is only arranged at the end part of the conducting rod 12 (no arc extinguishing functional component needs to be arranged on the first conducting end in a matching manner), and the arc extinguishing device has the characteristics of simpler structure and more ingenious design. And the inner cavity 123 of the conducting rod is hollow, so that a relatively large enough gas accommodating space can be provided, and favorable basic conditions are provided for forming higher-pressure and higher-speed arc extinguishing air flows. The air-compressing arc-extinguishing structure and the gas-generating arc-extinguishing structure are combined organically and smartly, so that the arc-extinguishing efficiency is improved, the cost is reduced, and the miniaturization of a product is realized.

The first contact 111 and the second contact 131 used in this embodiment are plum-blossom-shaped contact pieces, and in other embodiments, they may be ring-shaped spring contact fingers or a conductive ring sleeve including a plurality of longitudinally extending claws, or similar contact structures that can be conductively connected in an encircling manner.

Although the sealing ring 1342 is coupled with the piston rod 134 to form a piston structure sealed with the cavity 123 in this embodiment, in other embodiments, a rubber plug may be coupled to the first end of the piston rod 134 instead of the sealing ring 1342. In addition, in other embodiments, the crank arm 14 may be replaced with any driving structure that can drive the conductive rod 12 to move up and down.

Example two

FIG. 4 is an enlarged schematic view of a second preferred embodiment of the present invention showing a switch gas flow nozzle and a movable arcing contact; fig. 5A is a schematic cross-sectional view of a movable arcing contact of a switch according to a second preferred embodiment of the present invention. Fig. 5B is a top view of a movable arcing contact of a switch according to a second preferred embodiment of the present invention.

Fig. 4, 5A, and 5B correspond to a second embodiment of the present invention, in this embodiment, optimization and improvement are mainly performed on the air flow nozzle 15 and the movable arcing contact 16, and other parts refer to the description of the first embodiment, and are not described again. The conventional air flow nozzle has no cavity for accumulating air flow at all or has no research and design on the air flow field ejected from the air flow nozzle 15.

Referring specifically to FIG. 4, there is shown an enlarged detail view of the first end 121 of the conductive rod 12, in which the configuration of the cavity 152 of the air flow nozzle 15 is clearly visible; details of the movable arcing contact 16 can be clearly seen in fig. 5A and 5B.

Wherein, the end of the first end 121 of the conducting rod 12 is combined with the air flow nozzle 15 in a convex shape. The air flow nozzle 15 includes a throat 153 in addition to the cavity 151 and the tip 152. The throat 153 is located below the tip 152 and is a reduced diameter portion (i.e., narrower than the adjacent portion) for the cavity 151 and the connecting tip 152. In this embodiment, the throat 153 is provided with at least one air flow guiding groove 1531, and the air flow guiding groove 1531 may be a circular, single spiral, double spiral, or a plurality of discrete spiral line segments, and is disposed at the critical portion of the throat 153 where the air flow needs to pass, so that the air flow ejected from the nozzle tip 152 generates a spiral effect, thereby enhancing the arc extinguishing capability.

In order to further improve the arc extinguishing capability of the airflow ejected from the airflow nozzle 15, in the embodiment, the inner wall of the cavity 151 of the airflow nozzle 15 is also modified. As shown in fig. 4 in particular, a slope 1512 (preferably indicated by a bold oblique line below the throat 153) is provided at a position where the inner wall 1511 of the cavity 151 connects to the lower portion of the nozzle 152, the slope 1512 inclines from top to bottom toward the nozzle 152, an inverted "eight" shape is formed on both sides of the nozzle 152, an included angle 1513, preferably 40-80 °, which is smaller than or equal to 90 ° with the axial direction of the conducting rod 12 is formed, and the included angle causes the gas to be recoiled and blown to the root of the arc after converging at this position, thereby improving the arc extinguishing capability.

With reference again to fig. 5A, the movable arcing contact 16 is optimized in detail. The movable arcing contact 16 includes a movable arcing contact body 161 and a contact piece 162 extending upward from the middle of the driven arcing contact body 161, and the movable arcing contact body 161 is electrically connected to the conductive rod 12. The contact piece 162 is a cylindrical structure formed by a plurality of petal-shaped elastic contact pieces, and the inner diameter of the cylindrical structure is slightly larger than or almost equal to the outer diameter of the static arcing contact 114, and the static arcing contact 114 can be inserted into the center of the contact piece 162 and penetrate a distance below the movable arcing contact body 161 (in the embodiment, the lower end of the static arcing contact 114 is closer to the lower end of the first contact 111 and closer to the conductive rod 12 than the lower end of the first contact). The contact piece 162 can be kept by the elastic force of the contact piece 162 which is retracted inwards, so that the contact piece 162 can still form reliable conductive connection with the static arcing contact 114 in the process that the movable arcing contact 16 is relatively far away from the static arcing contact 114, the current can be transferred from an arcing contact loop to a conductive loop (the loop where the first contact 111 and the second contact 131 are located is called as the conductive loop) when the current is cut off, and the current transfer capability of the switch is improved. The gas generating element 17 is sleeved outside the petal-shaped elastic contact piece 162 of the movable arcing contact 16, so that arc extinguishing gas is generated by utilizing the arc energy near the movable arcing contact 16 to the maximum extent. A plurality of groove structures for fixing the gas generating element 17 (gas generating ring) may be further provided on the movable ignition contact body 161 around the outside of the contact piece 162. The structure of the petal-shaped elastic contact piece can be explained into any structure comprising a plurality of elastic conductive pieces with a longitudinal groove between every two as shown in fig. 5A or 5B.

Referring to fig. 5A and 5B, the movable arcing contact body 161 is provided with a plurality of through holes 1611, and the through holes 1611 are preferably formed in a central symmetrical manner with respect to the contact piece 162. Since the movable arcing contact body 161 is electrically connected and fixed at the end of the cavity 123 of the conductive rod 12 by its periphery, the through holes 1611 not only can smoothly guide the compressed air (the hole in the center of the contact piece 162 for inserting the static arcing contact 114 can also guide the air), but also can further increase the air pressure of the air, and the air can symmetrically flow to the nozzle tip 152 of the nozzle, so as to prevent the speed loss caused by the uneven flow of the air.

In the present embodiment, in the open state of the load switch, the end of the conductive rod 12 and the first contact 111 are purely insulating fractures, and the functions of the load switch and the disconnector are realized at the same time. The technical personnel in the field should understand that a pure insulation fracture refers to that when a static contact and a moving contact are in a brake separating position, no other substances are bridged between the static contact and the moving contact except for an aerated body; some products in the prior art have bridges made of materials that are mainly insulating materials, such as epoxy, teflon, polycarbonate, etc.

The above description is only a representative embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention.

Claims (15)

1. An arc extinguishing load switch comprises a first conducting end, a second conducting end and a conducting rod capable of being driven to reciprocate, and switching on or switching off of the first conducting end and the second conducting end is realized through the reciprocating motion of the conducting rod; the method is characterized in that:

the first conductive end comprises a first contact, and the conductive rod can be in conductive connection with the first contact when moving to the first conductive end and contacting with the first conductive end;

the second conductive end comprises a piston and a second contact; the second contact is arranged on the outer side of the piston, and a gap is formed between the second contact and the piston;

the conducting rod is of a hollow structure with a cavity; the conductive rod is arranged in the gap, the piston is accommodated in the cavity, the second contact is contacted with the outer surface of the conductive rod, and the second contact is electrically connected with the conductive rod in the motion process; the piston and the cavity form a gas containing space with variable volume;

the conductive rod comprises a first end facing the first conductive end and a second end facing the second conductive end; wherein the first end of the conducting rod is provided with an airflow nozzle communicated with the gas containing space and a gas generating element;

the conducting rod moves towards the direction close to the first conducting end to be in conducting connection with the first conducting end, a switching-on state is achieved, and the volume of the gas containing space is increased;

the conducting rod moves towards the direction far away from the first conducting end to be separated from the first conducting end, the switching-off state is achieved, the gas generating element receives arc energy generated when the conducting rod is separated from the first contact, and arc extinguishing gas is released to extinguish the arc; meanwhile, the volume of the gas containing space is reduced to generate gas flow, and the gas flow is sprayed out from the gas flow nozzle to extinguish the electric arc;

the air flow nozzle comprises a hollow cavity and a nozzle head, and the nozzle head is arranged at the top of the air flow nozzle and used for spraying air flow; the airflow nozzle is combined at the first end of the conductive rod by the bottom of the airflow nozzle, and the cavity is arranged between the top and the bottom of the airflow nozzle;

the gas generating element is arranged in the cavity of the gas flow nozzle.

2. The arc quenching load switch of claim 1, wherein: the first conductive end also comprises a first contact seat and a static arcing contact, and the first contact and the static arcing contact are both fixed and are electrically connected with the first contact seat; the end of the static arcing contact is closer to the conductive rod than the first contact; and the first end of the conducting rod is also provided with a movable arc striking contact which is in fit connection with the static arc striking contact, and the movable arc striking contact is in conductive connection with the conducting rod.

3. The arc quenching load switch of claim 2, wherein: the movable arcing contact comprises a movable arcing contact body and a plurality of petal-shaped elastic contact pieces vertically extending from the movable arcing contact body; the movable arcing contact body is electrically connected with the conducting rod; the petal-shaped elastic contact piece is annular and can surround the outside of the static arcing contact, so that the static arcing contact and the dynamic arcing contact are still in conductive connection at the moment of switching off, and current can be transferred to an arcing contact loop from a conductive end loop.

4. The arc quenching load switch of claim 3, wherein: the movable arc-striking contact is positioned at the bottom of the cavity of the gas flow nozzle, and the gas-generating element is arranged between the inner wall of the gas flow nozzle and the movable arc-striking contact.

5. The arc quenching load switch of claim 4, wherein: the gas generating element is a gas generating ring made of a gas generating material, and the gas generating ring is sleeved outside the petal-shaped elastic contact piece of the movable striking arc contact.

6. The arc quenching load switch of claim 5, wherein: the movable striking arc contact body is provided with a plurality of through holes, and the positions of the through holes are centered on the petal-shaped elastic contact piece to form central symmetry.

7. The arc quenching load switch of claim 1, wherein: the air flow nozzle also comprises a throat part, the throat part is positioned below the nozzle head and is used for connecting the cavity, and the throat part is provided with at least one air flow guide groove, so that air flow sprayed out of the nozzle head generates a spiral effect.

8. The arc quenching load switch of claim 7, wherein: the air flow guide groove is a circular, continuous spiral line or a discrete spiral line segment.

9. The arc quenching load switch of claim 1, 7 or 8, wherein: the inner wall of the cavity of the airflow nozzle is provided with an inclined plane at a position connected to the lower part of the nozzle head, the inclined plane is distributed on two sides of the nozzle head in an inverted splayed manner, and an included angle smaller than or equal to 90 degrees is formed between the inclined plane and the axial direction of the conducting rod.

10. The arc quenching load switch of claim 9, wherein: the included angle is 40-80 degrees.

11. The arc quenching load switch of claim 1, wherein: the piston is arranged at one end of a piston rod, and the other end of the piston rod is fixed on the piston rod base.

12. The arc quenching load switch of claim 1, wherein: the second contact and/or the first contact is a ring-shaped conductive contact with inward elastic force, the second contact is arranged outside the piston in a ring mode, and the gap is formed between the second contact and the piston; the second contact surrounds the outside of the conducting rod by means of inward elastic force of the second contact, so that the conducting rod is always in conductive connection with the second contact in the reciprocating movement process; the first contact is in conductive connection with the conductive rod which is continuously close to the first contact by virtue of the inward elastic force of the first contact.

13. The arc quenching load switch of claim 12, wherein: the second contact and the first contact are a plum-blossom contact piece, an annular spring contact finger or a conductive ring sleeve containing a plurality of claws extending longitudinally.

14. The arc quenching load switch of claim 1, wherein: the outside of the conducting rod is connected with a crank arm, and the crank arm drives the conducting rod to move up and down, so that switching-on and switching-off operations are realized.

15. The arc quenching load switch of claim 2, wherein: the inner diameter formed by a plurality of petal-shaped elastic contact pieces of the movable striking arc contact is smaller than the outer diameter of the static striking arc contact, and the movable striking arc contact is made of arc-resistant copper-tungsten materials.

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