Background
The prior art (patent number: 201610674268.2) discloses a technology of a motor relay capable of realizing rapid contact closing, which is a built-in load switch used in an intelligent ammeter, wherein a contact system of the motor relay is contacted in a reed form, the opening distance is 2mm-3mm, and the contact form has the problems that the current carrying area of a movable spring piece is small, and the temperature rise of a product is influenced; the open distance is small, and the arc breaking capability is extremely limited. For loads requiring switching of 80A current or even larger in the smart meter, the arc breaking capability of the contact system directly affects the reliability of the operation of the smart meter.
The prior art (patent number: 201720803291.7) discloses a technology of a motor type stable relay, which is a load switch that adopts a motor to drive a gear reduction mechanism, and a final gear drives a pushing block to push a movable spring to drive a movable contact and a static contact to realize the function of opening and closing the contacts. The load switch adopts a gear speed reducing mechanism, a gear approaches a constant speed to push a movable reed to walk through the whole contact gap process, the action time is too long, the contact is in the closing final stage because the teeth of a crown type gear are disengaged, then the teeth of the crown type gear are re-engaged with a preceding stage gear under the action of the reaction force of the movable reed, the shaking generated by the action causes the contact to have the shaking risk in the closing process, and the contact is easily burnt by the arcing generated when the distance between the movable contact and the fixed contact is very small, so the use safety of the load switch is seriously damaged.
Therefore, the contact of the load switch is improved, the opening speed is increased, the opening distance of the contact is increased, the arc breaking capacity is enhanced, and the fault percentage of the load switch in the operation of the intelligent electric meter is greatly reduced. Part 8 of technical specification of components for electric energy meters was issued by the national grid company in 2016: the load switch clearly stipulates that the electrical clearance of a load switch arranged in an electric energy meter is not less than 5.5mm, the creepage distance is not less than 6.3mm, the opening and closing time is less than 90ms, and after a short-circuit current bearing capacity test of 4.5kA, the load switch is not required to explode and has no damage to the appearance.
In summary, there is a need for a small-sized load switch suitable for a smart meter, which has a contact point that is fast and reliable in contact, can switch 80A current, and does not generate an excessive arc even when a larger current flows, and does not burn or melt the contact point due to arc discharge.
Disclosure of Invention
The invention aims to provide a load switch, which has the advantages that the contact of the switch is fast and reliable in contact, and the contact is not burnt and melted due to arc discharge.
In order to achieve the above object, the present invention discloses a load switch, including a motor-driven reduction gear assembly, a moving contact assembly, an operating assembly rotatably connected to the motor-driven reduction gear assembly and the moving contact assembly, a stationary contact assembly, at least one connecting rod connecting the operating assembly and the moving contact assembly, and an arc extinguishing device;
the movable contact assembly can rotate around a shaft, and when the motor drives the reduction gear assembly to drive the movable contact assembly to rotate through the operating assembly and the connecting rod, a movable contact on the movable contact assembly is connected with or disconnected from a fixed contact assembly.
Preferably, the arc extinguishing device further comprises an insulating housing for fixing the motor-driven reduction gear assembly, the moving contact assembly, the operating assembly, the fixed contact assembly, the at least one connecting rod and the arc extinguishing device.
Preferably, the arc extinguishing device is arranged side by side with the moving contact component and the static contact component.
Preferably, the maximum distance separating the moving alloy contact of the moving contact component and the static alloy contact of the static contact component when in disjunction is not less than 3.8 mm.
Preferably, the moving contact assembly comprises a moving contact rod and a moving alloy contact, and the moving alloy contact is arranged on the moving contact rod.
Preferably, the moving contact assembly further comprises a contact support connected with the moving contact rod, one end of the connecting rod is connected with the contact support, and the contact support can translate or rotate relative to the insulating shell.
Preferably, the shaft penetrates through the movable contact rod and the contact holder, and the movable contact rod is further connected with the contact holder through a first elastic member.
Preferably, the contact support is further provided with a buckle, and the movable contact rod is arranged in the buckle.
Preferably, both ends of the shaft are disposed on the insulating housing.
Preferably, the contact support is provided with a sliding groove, and the insulating housing is provided with a positioning block or a sliding rail matched with the sliding groove.
Preferably, the contact support is provided with at least two limiting columns, and the moving contact rod is arranged in the at least two limiting columns.
Preferably, a second elastic member is provided between the movable contact rod or the contact support and the insulating housing.
Preferably, the arc extinguishing device is formed by riveting at least one grid and a riveting plate or is formed by fixedly arranging at least one grid in an insulating shell.
Preferably, the connecting rod and the operating assembly are disposed between the motor-driven reduction gear assembly and the moving contact assembly.
Preferably, the operation assembly is provided with a driven gear and a driven disc, at least one limiting block and at least one first limiting groove matched with the limiting block are arranged between the driven gear and the driven disc, and the width of the first limiting groove is larger than that of the first limiting block.
Preferably, at least one boss is arranged on the driven disc, and a first stop block used for limiting the at least one boss is arranged on the insulating shell.
Preferably, the motor-driven reduction gear assembly comprises a motor-driven assembly and a reduction gear assembly, and the reduction gear assembly and the motor-driven assembly are of an integrated or separately installed structure.
Preferably, the reduction gear assembly comprises at least one reduction gear.
Preferably, the transmission mode of the motor driving assembly and the reduction gear assembly is worm gear, sector gear, bevel gear or crank-link transmission.
Preferably, the transmission mode of the motor-driven reduction gear assembly and the operation assembly is worm gear, sector gear, bevel gear or crank-link transmission.
The invention has the following beneficial effects:
1. the load switch can realize large opening distance not less than 3.8mm under a small-volume structure, realize quick closing and opening, reliably switch 100A heavy-current load, quickly extinguish electric arc through the arc extinguishing device, protect contacts from phenomena of burning, fusion welding and the like, and improve the operation reliability of the intelligent electric meter.
2. The load switch provided by the invention can realize remote automatic switching on and switching off by adopting the electric operating mechanism, does not need manual intervention, and has high intelligent degree.
Detailed Description
Features and exemplary embodiments of various aspects of the present invention will be described in detail below. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without some of these specific details. The following description of the embodiments is merely intended to provide a better understanding of the present invention by illustrating examples of the present invention. The present invention is in no way limited to any specific configuration and algorithm set forth below, but rather covers any modification, replacement or improvement of elements, components or algorithms without departing from the spirit of the invention. In the drawings and the following description, well-known structures and techniques are not shown in order to avoid unnecessarily obscuring the present invention.
First embodiment
As shown in fig. 1 to 10, the present embodiment discloses a load switch, which includes a motor-driven reduction gear assembly 200, a movable contact assembly 400, an operating assembly 300 rotatably connected to the motor-driven reduction gear assembly 200 and the movable contact assembly 400, a stationary contact assembly 500, at least one connecting rod 600 connecting the operating assembly 300 and the movable contact assembly 400, and an arc extinguishing device 700.
The movable contact assembly 400 can rotate around a shaft 800, and when the motor-driven reduction gear assembly 200 drives the movable contact assembly 400 to rotate through the operating assembly 300 and the connecting rod 600, the movable contact 420 on the movable contact assembly 400 is connected with or disconnected from the fixed contact assembly 500, as shown in fig. 2 and 1.
The load switch adopts the motor to drive the reduction gear assembly 200 to drive the moving contact assembly 400, can realize large opening distance not less than 3.8mm under a small volume structure, realize quick closing and opening, reliably switch 100A heavy current load, quickly extinguish electric arc through the arc extinguishing device, protect contacts from phenomena of burning, fusion welding and the like, and improve the operation reliability of the intelligent electric meter. Meanwhile, the electric operating mechanism can realize remote automatic switching on and switching off of the moving contact assembly 400 and the static contact assembly 500, manual intervention is not needed, and the intelligent degree is high.
As a preferred embodiment, as shown in fig. 3, the load switch further includes an insulating housing 100 for fixing the motor-driven reduction gear assembly 200, the movable contact assembly 400, the operating assembly 300, the stationary contact assembly 500, the at least one connecting rod 600, and the arc extinguishing device 700 to provide support for the motor-driven reduction gear assembly 200, the movable contact assembly 400, the operating assembly 300, the stationary contact assembly 500, the at least one connecting rod 600, and the arc extinguishing device 700. Specifically, the insulation housing 100 may include an upper cover 110 and a lower cover 120, and the upper cover 110 and the lower cover 120 may be connected together by screw fastening or snap fastening.
In a preferred embodiment, the connecting rod 600 is connected to the operating assembly 300 and the movable contact assembly 400, and can move or rotate relative to the connecting rod 600 and the operating assembly 300.
In a preferred embodiment, the connecting rod 600 and the operating assembly 300 are disposed between the motor-driven reduction gear assembly 200 and the movable contact assembly 400.
As a preferred embodiment, the motor-driven reduction gear assembly 200 includes a motor-driven assembly 210 and a reduction gear assembly 220, the motor-driven assembly 210 and the reduction gear assembly 220 may be an integrated structure, or may be a separately installed structure, when the motor-driven assembly 210 and the reduction gear assembly 220 are an integrated structure, the reduction gear assembly 220 may be installed and sleeved on the rotating shaft of the motor-driven assembly 210 in the form of a reduction gear box, and the reduction is achieved by driving the motor-driven assembly 210, and the rotating directions of the motor-driven assembly 210 and the reduction gear assembly 220 are the same. Further, the reduction gear assembly 220 includes at least one reduction gear.
As a preferred embodiment, the motor driving assembly 210 and the reduction gear assembly 220 are separate structures, the number of the reduction gears of the reduction gear assembly 220 may be 2, specifically, the reduction gear assembly 220 includes a first driving gear 221 and a second driving gear 222, the first driving gear 221 and the second driving gear 222 are concentrically arranged, a helical gear on the first driving gear 221 is engaged with a rack on a rotating shaft of the motor driving assembly 210, the second driving gear 222 is a spur gear, when the motor driving assembly 210 rotates, the first driving gear 221 rotates under the driving of the rotating shaft of the motor driving assembly 210, and the second driving gear 222 synchronously rotates under the driving of the first driving gear 221. It is easy to think that the above embodiment is only one of the driving manners of the motor driving assembly 210 and the reduction gear assembly 220, and the driving manners of the motor driving assembly 210 and the reduction gear assembly 220 include, but are not limited to, transmission manners such as worm and gear, sector gear, bevel gear, crank and link, etc., and the same effect can be achieved. In addition, the motor driving component 210 may receive a signal from the outside, for example, the motor driving component 210 may be connected to an electronic controller, the electronic controller may send a command for turning on or off, and the motor driving component 210 may rotate counterclockwise or clockwise after receiving the signal sent by the electronic controller, so as to turn on or off the load switch, without manual intervention, and may implement remote control of the switch state, and the degree of automation is high.
As shown in fig. 4, the operating assembly 300 includes a driven gear 310 and a driven disc 320, the driven gear 310 and the driven disc 320 are concentrically disposed, the driven gear 310 is a spur gear and is engaged with the second driving gear 222 to be rotated by the second driving gear 222, and the driven disc 320 is rotated by the driven gear 310. Of course, the transmission of the motor-driven reduction gear assembly 200 and the operating assembly 300 may include, but is not limited to, worm gears, sector gears, bevel gears, crank links, etc.
Preferably, as shown in fig. 5, in this embodiment, a limiting block 311 is disposed on the driven gear 310, a limiting groove 321 is disposed on the driven disc 320, the limiting groove 321 is matched with the limiting block 311, the limiting block 311 can rotate in the limiting groove 321, a width of the first limiting groove 321 is greater than a width of the limiting block 311, and a spatial angle capable of allowing the limiting block 311 to rotate is preset between two side walls of the first limiting groove 321, so that a preset idle stroke is formed between the rotation of the driven disc 320 and the rotation of the driven gear 310.
As shown in fig. 6, a boss 322 is further provided on the driven plate 320, the first stopper 111 is provided on the upper cover 110, the second stopper 121 is provided on the lower cover 120, and the boss 322 is rotatable between the first stopper 111 and the second stopper 121, thereby limiting a rotation angle of the driven plate 320. The number of the bosses 322 may be one, or may be plural, and is not limited herein.
As shown in fig. 7, the movable contact assembly 400 includes a movable contact rod 410 and a movable alloy contact 420, wherein the movable alloy contact 420 is disposed on the movable contact rod 410. Preferably, the movable contact assembly 400 further includes a movable contact support 430, and the movable alloy contact 420 is disposed on the movable contact rod 410 and is closed or opened with the static alloy contact 511 on the static contact assembly 500. One end of the moving contact rod 410 is arranged between the wire inlet end 510 and the wire outlet end 480, and the wire inlet end 510 and the wire outlet end 480 of the load switch are arranged on the same side of the load switch. The moving contact assembly 400 is provided with a shaft 800, the moving contact rod 410 and the contact support 430 are provided with through holes 401 matched with the shaft 800, the moving contact rod 410 and the moving contact support 430 can rotate around the shaft 800, and when the moving contact assembly 400 rotates, the maximum distance between a moving alloy contact 420 on the moving contact assembly 400 and a static alloy contact 511 on the static contact assembly 500 is not less than 3.8 mm. The shaft 800 penetrates through the through hole 401, and two ends of the shaft 800 are respectively fixed on the upper cover 110 and the lower cover 120, so that the movable contact assembly 400 is fixed.
A first elastic member 440 is disposed between the contact holder 430 and the movable contact rod 410, and both ends of the first elastic member 440 are respectively in contact with the contact holder 430 and the movable contact rod 410 and provide a contact pressure for the movable alloy contact 420 to be in contact with the static alloy contact 511. Specifically, a first limit boss 411 is disposed on the moving contact rod 410, a second limit groove 431 is disposed on the contact support 430, one end of the first elastic member 440 is sleeved on the first limit boss 411, and the other end of the first elastic member 440 is disposed on the second limit groove 431, in this embodiment, the first elastic member 440 is preferably a spring.
A second elastic element 450 is arranged between the movable contact assembly 400 and the insulating housing 100, one end of the second elastic element 450 is in contact with the insulating housing 100, the other end of the second elastic element is in contact with the contact support 430, a third limiting groove 432 is arranged on the contact support 430, a second limiting boss 433 is further arranged in the third limiting groove 432, one end of the second elastic element 450 is arranged in the third limiting groove 432 and is sleeved on the second limiting boss 433, and a quick disconnection acting force is provided for the movable contact assembly 400 after the contact passes a dead point.
The connecting rod 600 is disposed between the operating assembly 300 and the moving contact assembly 400, and two ends of the connecting rod 600 are movably connected to the operating assembly 300 and the moving contact assembly 400, respectively. Preferably, the connecting rod 600 has a U-shaped structure, one end 610 of the connecting rod 600 is clamped into the driven plate 320, and the other end 620 of the connecting rod 600 is clamped onto the contact support 430, and can rotate relative to the driven plate 320 and the movable contact assembly 400, respectively. A rotation connection point of the connection rod 600 and the driven disc 320 is a, a rotation connection point of the connection rod 600 and the movable contact assembly 400 is B, a rotation center of the driven disc 320 is C, a straight line between the points a and C is set to be L1, a straight line between the points a and B is set to be L2, the length of L1 is not greater than the maximum distance of the movable contact assembly 400 and the fixed contact assembly 500, an angle between L1 and L2 is 45 ° to 95 °, and when three points A, B, C form a straight line, the movable contact assembly 400 is located at a dead point.
In a preferred embodiment, a buckle 434 is further disposed on the contact support 430, the movable contact rod 410 is disposed in the buckle 434, the buckle 434 can limit the movable contact rod 410, so that the movable contact rod 410 and the contact support 430 are kept in a relatively static state, when the movable alloy contact 420 is in contact with the static alloy contact 511, the contact support 430 continues to rotate under the action of the connecting rod 600, at this time, due to the limit of the static alloy contact 511, the movable contact rod 410 and the contact support 430 are separated, and under the constraint of the buckle 434, the movable contact rod 410 and the contact support 430 overcome the separation phenomenon, thereby achieving the stability of the movable contact assembly 400.
In a preferred embodiment, the load switch is provided with an arc extinguishing device 700, the arc extinguishing device is arranged between the incoming line terminal 510 and the outgoing line terminal 480 of the load switch, and is substantially in a digital "7" shape, the arc extinguishing device 700 is arranged side by side with the moving contact assembly 400 and the static contact assembly 500, and the side by side arrangement means that the arc extinguishing device 700 is arranged corresponding to the moving contact assembly 400 and the static contact assembly 500, and more preferably, can be arranged side by side with the moving contact assembly 400 and the static contact assembly 500 along a direction perpendicular to a plane in which the moving contact assembly 400 and the static contact assembly 500 are located. The arc generated when the moving contact assembly 400 is disconnected from the stationary contact assembly 500 may enter the arc extinguishing device 700 to be cut and cooled, thereby achieving the purpose of arc extinguishing. As shown in fig. 8, the arc extinguishing device 700 includes more than one grid 710 and riveting plates 720, the grid 710 and the riveting plates 720 are installed in the insulating housing 100 after being riveted and formed, and a clamping groove is formed in the insulating housing 100, and the clamping groove can limit and fix the arc extinguishing device 700. Of course, in another embodiment, the arc extinguishing device 700 may not be provided with the riveting plate 720, and the grid 710 may be directly clamped into the clamping groove on the insulating housing 100, so as to achieve the arc extinguishing effect.
The following detailed description is provided for the closing or opening process of the movable contact assembly 400:
when the movable contact assembly 400 is closed, firstly, the motor driving assembly 210 rotates counterclockwise to drive the first driving gear 221 to rotate counterclockwise, the first driving gear 221 drives the second driving gear 222 to rotate synchronously, the second driving gear 222 drives the driven gear 310 to rotate synchronously, when one side of the limiting block 311 on the driven gear 310 contacts with the side wall of the first limiting groove 321 on the driven disk 320, the driven disk 320 rotates synchronously under the driving of the driven gear 310, the connecting rod 600 rotates under the driving of the driven disk 320 to drive the movable contact assembly 400 to rotate around the shaft 800, the movable contact assembly 400 rotates synchronously towards the direction close to the fixed contact assembly 500 under the driving of the connecting rod 600 until the movable contact assembly 400 contacts with the fixed contact assembly 500, when the boss 322 on the driven disc 320 contacts with the first stopper 111, the driven disc 320 stops rotating, and during this state, the first elastic member 440 and the second elastic member 450 are both compressed, and the first elastic member 440 provides a contact pressure of the alloy contact 420 with the alloy contact 511.
When the moving contact assembly 400 is disconnected, the moving process is the same as the closed state, except that at this time, the motor driving assembly 210 rotates clockwise, the limit block 311 on the driven wheel 310 moves from one side wall of the first limit groove 321 to the other side wall, in this process, before the limit block 311 contacts with the other side wall of the first limit groove 321, the driven gear 310 needs to pass through a section of idle stroke, in this process, the driven disc 320 does not rotate together with the driven gear 310, after the limit block 311 contacts with the other side wall of the first limit groove 321, the driven disc 320 is driven to rotate clockwise, after the moving contact assembly 400 passes a dead point, the moving contact assembly 400 is driven to rotate in a direction away from the fixed contact assembly 500, and the idle stroke between the driven disc 320 and the driven wheel 310 can be used for disengaging the constraint of gear engagement transmission, the movable contact assembly 400 can be quickly disconnected from the stationary contact assembly 500 under the elastic force of the second elastic member 450, and when the boss 322 on the driven plate 320 contacts the second stopper 121, the driven plate 320 stops rotating.
Second embodiment
In this embodiment, the load switch may be implemented in other manners as well, as shown in fig. 9 and 10. In this embodiment, the shaft 800 passes through the movable contact rod 410, and two ends of the shaft 800 are respectively fixed on the upper cover 110 and the lower cover 120 of the insulating housing 100, the movable contact rod 410 can rotate around the shaft 800, two ends of the connecting rod 600 are respectively movably connected with the operating assembly 300 and the contact support 430, when the operating assembly 300 is driven by the motor reduction gear assembly 200 to rotate, the contact support 430 can translate relative to the insulating housing 100 under the drive of the connecting rod 600, a sliding groove 436 is arranged at the bottom of the contact support 430, a positioning block or a sliding rail matched with the sliding groove 436 is arranged on the insulating housing 100, the contact support 430 can translate along the positioning block or the sliding rail, two raised limiting columns 435 are arranged on the contact support 430, the movable contact rod 410 is arranged in the at least two limiting columns 435, the contact holder 430 is in contact with the insulation housing 100 by virtue of the pressure provided by the movable contact rod 410, and when the contact holder 430 is driven by the connecting rod 600 to move horizontally relative to the insulation housing 100, the movable contact rod 410 can be pushed to rotate around the shaft 800 by virtue of the limiting column 435, so that the movable alloy contact 420 and the static alloy contact 511 are closed or opened. At this time, the second elastic member 450 is disposed between the movable contact rod 410 and the insulating housing 100, the second elastic member 450 has the same function as that of the first embodiment, and the structure and connection relationship of the motor-driven reduction gear assembly 200 and the operation assembly 300 in this embodiment are the same as those in the first embodiment, and thus, no further description is given here.
The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the system embodiment, since it is substantially similar to the method embodiment, the description is simple, and for the relevant points, reference may be made to the partial description of the method embodiment.
The above description is only an example of the present application and is not intended to limit the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.