Arc extinguishing device of circuit breaker

Abstract

The utility model relates to the technical field of electrical equipment, and discloses an arc extinguishing device of a circuit breaker, which comprises an insulating medium ejector, an ejection driving assembly and an operating handle used for driving a moving contact and a static contact to be closed or opened. The insulating medium ejector is provided with a spray head opposite to the contact closing position of the moving contact and the static contact; the operating handle is connected with the spraying driving assembly, and the spraying driving assembly is connected with the spraying head; when the operating handle drives the moving contact and the static contact to be connected or disconnected, the spraying driving assembly drives the spraying head to start spraying. The circuit breaker arc extinguishing device of the utility model can realize instant and efficient arc extinguishing.

Description

Technical Field

[0001] The utility model relates to the technical field of electrical equipment, in particular to an arc extinguishing device for a circuit breaker. Background Art

[0002] In order to reduce the burning of the contact by the arc and limit the space for the arc to expand, measures to enhance the arc extinguishing ability are usually required, and the device used for this purpose is called an arc extinguishing device.

[0003] At present, the arc extinguishing strategies in circuit breakers are as follows:

[0004] (1) Electromagnetic arc extinguishing method, which generates a magnetic field through the change of current, thereby destroying the ionization environment where the arc exists to achieve the arc extinguishing effect; it belongs to passive arc extinguishing.

[0005] (2) Arc stretching extinguishing method, which stretches the arc, dissipates heat through a longer path, and finally extinguishes the arc; it belongs to active arc extinguishing, but requires a large space, and the arc is broken rather than extinguished in advance, with poor effect.

[0006] (3) Grid plate arc extinguishing method, which uses metal plates to divide the arc into multiple short arcs, making it impossible to maintain the combustion state and thus extinguishing; it belongs to passive arc extinguishing.

[0007] (4) Physical and chemical arc extinguishing method, which uses some arc extinguishing substances, such as arc extinguishing oil. When the arc is generated, the arc extinguishing oil quickly evaporates to form arc extinguishing gas, thereby extinguishing the arc; it belongs to passive arc extinguishing.

[0008] (5) Vacuum arc extinguishing method, which places the switch contacts in a vacuum bubble. There are no free electrons in the vacuum, so no arc will be generated; this solution has good effect, but high cost and is only applicable to the scenario without arc.

[0009] (6) Zero-crossing arc extinguishing method, which detects the voltage signal, identifies the zero-crossing point of the voltage, and performs the switch operation at the zero-crossing moment, thus not generating an arc; it belongs to active arc extinguishing, but requires an accurate zero-crossing detection algorithm and is not easy to handle when the circuit breaker switches from on to off.

[0010] Most of the above arc extinguishing methods start to extinguish the arc after the arc is generated, with lag in arc extinguishing, and some have disadvantages such as relying on algorithms and limited applicable scenarios.

[0011] Therefore, it is necessary to develop an arc extinguishing device for a circuit breaker that can extinguish the arc instantaneously and efficiently. Summary of the Utility Model

[0012] The technical problem to be solved by the utility model is to provide an arc extinguishing device for a circuit breaker that can extinguish the arc instantaneously and efficiently.

[0013] To solve the above technical problems, the utility model provides a circuit breaker arc extinguishing device, which includes an insulating medium injector, an injection driving assembly, and an operating handle for driving the moving contact and the static contact to close or disconnect;

[0014] The insulating medium injector is provided with a nozzle opposite to the contact closing position of the moving contact and the static contact;

[0015] The operating handle is connected to the injection driving assembly, and the injection driving assembly is connected to the nozzle;

[0016] When the operating handle drives the moving contact and the static contact to close or disconnect, the injection driving assembly drives the nozzle to start spraying.

[0017] As an improvement of the above solution, the injection driving assembly includes a lever, a cam, and a gear transmission mechanism. One end of the lever is connected to the nozzle, and the other end is in contact with the cam. The operating handle is connected to the power input member of the gear transmission mechanism, and the cam is connected to the power output member of the gear transmission mechanism. The gear transmission mechanism is driven by the operating handle to drive the cam to rotate, and the cam drives the lever to open or close the nozzle.

[0018] As an improvement of the above solution, the power input member is a swing arm, the power output member is a transmission gear, the swing arm is coaxially connected to the operating handle, the cam is coaxially connected to the transmission gear, and the swing arm is provided with meshing teeth meshing with the transmission gear.

[0019] As an improvement of the above solution, the outer peripheral surface of the cam is provided with a first transmission surface, and the distance from the rotation center of the cam to each point on the first transmission surface is equal. When the first transmission surface contacts the lever, the lever drives the nozzle of the insulating medium injector to open.

[0020] As an improvement of the above solution, the outer peripheral surface of the cam is provided with at least two first transmission surfaces, and the distance from each first transmission surface to the rotation center of the cam is equal.

[0021] As an improvement of the above solution, the radian of adjacent two first transmission surfaces is different; and / or

[0022] The radian between adjacent two first transmission surfaces is different.

[0023] As an improvement of the above solution, the cam is provided with a second transmission surface, and the distance from the rotation center of the cam to each point on the second transmission surface is equal. When the second transmission surface contacts the lever, the nozzle of the insulating medium injector closes;

[0024] The cam is provided with a transition surface that smoothly transitions with the first transmission surface and the second transmission surface, and the lever is provided with a protrusion adapted to the transition surface.

[0025] As an improvement to the above solution, the injection direction of the insulating medium injector intersects with the moving direction of the moving contact;

[0026] Both the moving contact and the static contact are metal sheets. One end of the moving contact close to the nozzle is provided with a moving bending portion extending away from the static contact, and one end of the static contact close to the nozzle is provided with a static bending portion extending away from the moving contact. The nozzle is arranged between the static bending portion and the moving bending portion.

[0027] As an improvement to the above solution, an elastic reset member for driving the nozzle of the insulating medium injector to reset is provided inside the insulating medium injector.

[0028] As an improvement to the above solution, the insulating medium inside the insulating medium injector is at least one of sulfur hexafluoride gas, helium gas, and argon gas.

[0029] Implementing the present utility model has the following beneficial effects:

[0030] The present utility model discloses a circuit breaker arc extinguishing device. By linking the operating handle for driving the moving contact and the static contact to close or disconnect with the injection driving assembly for driving the insulating medium injector to open and inject, and the nozzle of the insulating medium injector is opposite to the contact closing position of the moving contact and the static contact. As long as the operating handle is toggled, while driving the moving contact to move, the insulating medium injector can be driven to inject the insulating medium directionally, that is, the arc extinguishing action of injecting the insulating medium is triggered along with the switching action of the contact, without relying on whether an arc is generated. This arc extinguishing device can implement an arc extinguishing strategy of injecting the insulating medium to the contact closing position to limit the generation and expansion of the arc instantaneously when the arc is generated, or even before the arc is generated;

[0031] The start of arc extinguishing does not need to rely on program control, which can avoid the failure of arc extinguishing caused by circuit control faults and has high reliability;

[0032] Since the arc is extinguished by the insulating medium as soon as it is generated, it does not need to rely on the thermal expansion of the gas after the arc is generated to achieve the arc blowing effect, and can achieve more active, more immediate, and more efficient arc extinguishing, which can better protect the contacts from being burned. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a schematic structural diagram of an embodiment of a circuit breaker arc extinguishing device of the present utility model when the moving contact and the static contact are disconnected;

[0034] Figure 2 is Figure 1 a side view of

[0035] Figure 3 is Figure 1 The schematic structural diagram of the arc extinguishing device of the circuit breaker at the first pulse injection;

[0036] Figure 4 is Figure 3 The side view of;

[0037] Figure 5 is Figure 1 The schematic structural diagram of the arc extinguishing device of the circuit breaker at the second pulse injection;

[0038] Figure 6 is Figure 5 The side view of;

[0039] Figure 7 is Figure 1 The schematic structural diagram of the arc extinguishing device of the circuit breaker at the third pulse injection;

[0040] Figure 8 is Figure 7 The side view of;

[0041] Figure 9 is Figure 1 The schematic structural diagram of the arc extinguishing device of the circuit breaker at the fourth pulse injection;

[0042] Figure 10 is Figure 9 The side view of;

[0043] Figure 11 is Figure 1 The schematic structural diagram of the arc extinguishing device of the circuit breaker when the moving contact and the static contact are closed and energized;

[0044] Figure 12 is Figure 11 The side view of;

[0045] Figure 13 The schematic structural diagram of the cam. Detailed implementation manners

[0046] To make the objectives, technical solutions and advantages of the present utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings.

[0047] Such as Figures 1 to 12As shown in the figure, an embodiment of an arc extinguishing device for a circuit breaker is disclosed in the present utility model, which includes an insulating medium injector 1, an injection driving assembly, and an operating handle 4 for driving the moving contact 2 to close or disconnect from the static contact 3; the insulating medium injector 1 is provided with a nozzle opposite to the contact closing position of the moving contact 2 and the static contact 3; the operating handle 4 is connected to the injection driving assembly, and the injection driving assembly is connected to the nozzle; when the operating handle 4 drives the moving contact 2 to close or disconnect from the static contact 3, the injection driving assembly drives the nozzle to start injecting.

[0048] Since the operating handle 4 for driving the moving contact 2 to close or disconnect from the static contact 3 in this embodiment is linked with the injection driving assembly for driving the insulating medium injector 1 to start injecting, and the nozzle of the insulating medium injector 1 is opposite to the contact closing position of the moving contact 2 and the static contact 3, as long as the operating handle 4 is toggled, while driving the moving contact 2 to move, the insulating medium injector 1 can be driven to inject the insulating medium directionally, that is, the arc extinguishing action of injecting the insulating medium is triggered along with the switching action of the contacts, regardless of whether an arc is generated. This arc extinguishing device can implement an arc extinguishing strategy of injecting the insulating medium towards the contact closing position at the moment when the arc is generated, or even before the arc is generated, to limit the generation and expansion of the arc; the start of arc extinguishing does not need to rely on program control, which can avoid the failure of arc extinguishing caused by circuit control faults and has high reliability; since the arc is extinguished by the insulating medium just when it is generated, it does not need to rely on the thermal expansion effect of the gas after the arc is generated to achieve the arc blowing effect, and can achieve more active, more immediate and more efficient arc extinguishing, which can better protect the contacts from being burned.

[0049] Among them, the intermediate transmission structure for driving the moving contact 2 to close or disconnect from the static contact 3 by the operating handle 4 can adopt the tripping structure of the existing circuit breaker switch, which is the prior art and will not be elaborated here.

[0050] It should be noted that different from the present utility model, the existing circuit breaker adopts a physical and chemical arc extinguishing method. For example, by setting an arc extinguishing chamber and media such as arc extinguishing oil, when an arc is generated, by using the blocking effect of the static arc contact and the arc on the nozzle and the thermal expansion effect of the arc on the gas, the arc extinguishing oil quickly evaporates to form an arc extinguishing gas, and quickly increases the arc blowing gas pressure in the arc extinguishing chamber, so that the arc extinguishing chamber has extremely strong arc extinguishing ability, thereby extinguishing the arc; after the arc is generated, it extinguishes the arc by means of the thermal effect of the arc on the surrounding environment, which belongs to passive arc extinguishing. While the present utility model can extinguish the arc by actively injecting the insulating medium towards the contact closing position at the moment when the arc is generated, or even before the arc is generated. The arc extinguishing reaction speeds and the thermal change processes of the insulating media of the two are different.

[0051] In addition to the operating handle 4 extending out of the housing 5 of the circuit breaker, the insulating medium injector 1 and the injection driving assembly are both arranged inside the housing 5 of the circuit breaker.

[0052] In this embodiment, the injection direction of the insulating medium injector 1 is vertically crossed with the movement direction of the moving contact 2.

[0053] An elastic reset member (not shown in the figure) for driving the nozzle to reset and close is provided in the insulating medium injector 1. In this embodiment, the elastic reset member in the insulating medium injector 1 applies a resilient force to the nozzle towards the side away from the contact closing position.

[0054] The insulating medium in the insulating medium injector 1 is preferably at least one of arc extinguishing gases such as sulfur hexafluoride gas, helium gas, and argon gas, and other types of arc extinguishing gases can also be used according to different scenarios.

[0055] Both the moving contact 2 and the static contact 3 are metal sheets. A moving bending portion extending away from the static contact 3 is provided at one end of the moving contact 2 close to the nozzle, and a static bending portion extending away from the moving contact 2 is provided at one end of the static contact 3 close to the nozzle. The nozzle is arranged between the static bending portion and the moving bending portion. On the one hand, it can ensure that the ejected insulating medium falls near the contact closing position, and on the other hand, it helps to reduce the travel of the insulating medium to the contact closing position and assist in rapid arc extinguishing.

[0056] The injection driving assembly in this embodiment specifically includes a lever 6, a cam 7, and a gear transmission mechanism. Among them, the middle of the lever 6 is hinged to the housing 5. One end of the lever 6 is connected to the nozzle, and the other end is in contact with the cam 7. The lever 6 can be sleeved outside the spray rod of the insulating medium injector 1 or clamped to the spray rod. The nozzle at the end of the spray rod and the cam 7 in contact with the cam 7 are both arranged on the same side of the lever 6, and the injection port of the nozzle faces the contact closing position of the moving contact 2 and the static contact 3.

[0057] The operating handle 4 is connected to the power input member of the gear transmission mechanism, the cam 7 is connected to the power output member of the gear transmission mechanism, the gear transmission mechanism is driven by the operating handle 4 to drive the cam 7 to rotate, and the cam 7 drives the lever 6 to open or close the nozzle.

[0058] In order to facilitate the layout inside the housing 5 and reduce the volume, the power input part in this embodiment is a swing arm 8, which is inside the housing 5 and coaxially connected to the operating handle 4. The swing arm 8 swings as the operating handle 4 rotates. The power output part is a transmission gear 9, the cam 7 is coaxially connected to the transmission gear 9, and the swing arm 8 is provided with meshing teeth that mesh with the transmission gear 9. Among them, the connecting shaft between the operating handle 4 and the swing arm 8, the connecting shaft between the transmission gear 9 and the cam 7, and the hinge axis of the lever 6 are all arranged in parallel. By turning the operating handle 4, the swing arm 8 is driven to swing, and the swing arm 8 further drives the transmission gear 9 and the cam 7 coaxially connected to the transmission gear 9 to rotate. The cam 7 changes the angle of rotation of the lever 6 relative to the hinge axis, so that the lever 6 overcomes the elastic force of the elastic reset member in the insulating medium injector 1, so that the nozzle starts to spray.

[0059] Specifically, combined Figure 13 The outer peripheral surface of the cam 7 is provided with a first transmission surface 71, and the rotation center of the cam 7 is at an equal distance from each point on the first transmission surface 71. When the first transmission surface 71 contacts the lever 6, the lever 6 drives the nozzle of the insulating medium injector 1 to open. Specifically, when the first transmission surface 71 contacts the lever 6, the lever 6 at this end rotates downward, and the other end of the lever 6 tilts upward, the lever 6 pulls the nozzle, and overcomes the rebound force of the elastic reset member on the nozzle, so that the nozzle opens to spray.

[0060] In addition, the cam 7 is provided with a second transmission surface 72, the rotation center of the cam 7 is at an equal distance from each point on the second transmission surface 72, and the distance between the second transmission surface 72 and the rotation center of the cam 7 is smaller than the distance between the first transmission surface 71 and the rotation center of the cam 7. When the second transmission surface 72 contacts the lever 6, the lifting effect of the lever 6 on the nozzle is weakened or disappears, and under the action of the rebound force of the elastic reset member, the nozzle of the insulating medium injector 1 is closed.

[0061] Among them, the cam 7 is provided with a transition surface 93 that smoothly transitions with the first transmission surface 71 and the second transmission surface 72, and the lever 6 is preferably provided with a protrusion 61 that adapts to the transition surface 93. During the rotation of the cam 7, the cam 7 and the lever 6 can maintain stable contact to prevent slipping.

[0062] Since in an alternating current circuit, an arc has a dynamic volt-ampere characteristic, that is, the instantaneous value of the current changes with time, and the temperature, diameter, and arc voltage of the arc also change with time (vary in a sine curve), in this embodiment, it is preferably provided that at least two of the first transmission surfaces 71 are provided on the outer peripheral surface of the cam 7, and the second transmission surface 72 is arranged between two adjacent first transmission surfaces 71, so as to intermittently open the nozzle of the insulating medium injector 1 during the process of the operating handle 4 driving the moving contact 2 to move, forming a jet pulse. Compared with continuous jet, such a jet pulse can divide the time when an arc is generated during closing and opening into several segments for arc extinguishing by jetting gas respectively, and can achieve efficient arc extinguishing.

[0063] In this embodiment, the distance between each of the first transmission surfaces 71 provided on the cam 7 and the rotation center of the cam 7 is set to be equal, and the radian of each first transmission surface 71 and the radian between two adjacent first transmission surfaces 71 are different, and can be specifically set according to needs, thereby realizing the adjustment of the duration and interval of the generation of the jet pulse according to the generation and change process of the arc.

[0064] In the arc extinguishing device of the circuit breaker of this embodiment, according to the change law of the sine wave, 4 first transmission surfaces 71 are provided on the cam 7, and 4 jet pulses will be experienced during the tripping process. Figures 1 to 12 The movement process of each transmission moving part for realizing jet arc extinguishing from the off state to the on state is given. Among them, during one pulse stroke (the process in which one of the first transmission surfaces 71 on the cam 7 contacts the lever 6 when the cam 7 rotates), the cam 7 presses the lever 6, thereby lifting the nozzle, and the insulating medium injector 1 opens to jet gas. Then, after passing through the second transmission surface 72 between one pulse stroke and two pulse strokes, the lever 6 returns to the origin, and the nozzle of the insulating medium injector 1 closes; then during two pulse strokes (the process in which another first transmission surface 71 on the cam 7 contacts the lever 6 when the cam 7 rotates), the insulating medium injector 1 jets gas for the second time, and so on, through three pulse strokes and four pulse strokes until the circuit breaker contacts are completely opened; the closing process is the same, only the movement direction is opposite.

[0065] More preferably, the distances between the first transmission surfaces 71 and the rotation center of the cam 7 can be set to be different, so that when different first transmission surfaces 71 contact the lever 6, the lever 6 exerts different magnitudes of force on the nozzle but sufficient to open the nozzle, forming different jet effects, realizing the adjustment of the jet flow rate according to the generation and change process of the arc, and achieving a better arc extinguishing effect.

[0066] Among them, the specific number of the first transmission surfaces 71 on the cam 7, the radian of each first transmission surface 71, the radian between two adjacent first transmission surfaces 71, as well as the number of the meshing teeth, the tooth pitch, the distance between the moving contact 2 and the static contact 3, the injection stroke, etc. will all affect the injection effect, and can be specifically set according to the change of the arc, so that during the process of tripping and closing, different degrees of arc extinguishing by injection can be carried out in different stages, achieving the purpose of precise control.

[0067] Apply the above circuit breaker arc extinguishing device to extinguish the arc of the circuit breaker contact. Before the moving contact 2 separates from the static contact 3, the insulating medium injector 1 intermittently sprays the insulating medium towards the contact closing position for multiple times.

[0068] Since the insulating medium injector 1 can spray the insulating medium towards the contact closing position, the insulating medium can drive away the ionizable air and fill the contact closing position, while playing a cooling role to avoid or weaken the generation and development of the arc.

[0069] The opening and closing of the insulating medium injector 1 do not need to rely on a control program, and pre-spray the insulating medium before the moving contact 2 separates from the static contact 3, which can effectively prevent the generation of the arc and ensure the safe operation of the circuit breaker.

[0070] The insulating medium injector 1 intermittently sprays the insulating medium towards the contact closing position for multiple times, which can divide the time of generating the arc during closing and opening into several sections to carry out arc extinguishing by jetting air respectively, and can design corresponding arc extinguishing strategies according to the specific usage situation, achieving refined and efficient arc extinguishing.

[0071] The above-disclosed is only a preferred embodiment of the present invention, and of course, it cannot be used to limit the scope of the rights of the present invention. Therefore, equivalent changes made according to the claims of the present invention still fall within the scope covered by the present invention.

Claims

1. A circuit breaker arc extinguishing device, characterized in that: It includes an insulating medium ejector, an ejection drive assembly, and an operating handle for driving the moving contact and the stationary contact to close or open; The insulating medium injector is provided with a nozzle opposite to the contact closing position of the moving contact and the stationary contact; The operating handle is connected to the jet drive assembly, and the jet drive assembly is connected to the nozzle; When the operating handle drives the moving contact and the stationary contact to close or open, the jet drive assembly drives the spray head to start spraying.

2. The circuit breaker arc extinguishing device according to claim 1, characterized in that: The jet drive assembly includes a lever, a cam and a gear transmission mechanism, one end of the lever is connected to the spray head, and the other end is in contact with the cam, the operating handle is connected to the power input part of the gear transmission mechanism, and the cam is connected to the power output part of the gear transmission mechanism. The gear transmission mechanism is driven by the operating handle to drive the cam to rotate, and the cam drives the lever to open or close the spray head.

3. The circuit breaker arc extinguishing device according to claim 2, characterized in that: The power input part is a swing arm, the power output part is a transmission gear, the swing arm is coaxially connected to the operating handle, the cam is coaxially connected to the transmission gear, and the swing arm is provided with meshing teeth meshing with the transmission gear.

4. The circuit breaker arc extinguishing device according to claim 2 or 3, characterized in that: The outer peripheral surface of the cam is provided with a first transmission surface, and the rotation center of the cam is at an equal distance from each point on the first transmission surface. When the first transmission surface contacts the lever, the lever drives the nozzle of the insulating medium injector to open.

5. The circuit breaker arc extinguishing device according to claim 4, characterized in that: The outer peripheral surface of the cam is provided with at least two first transmission surfaces, and each of the first transmission surfaces is equidistant from the rotation center of the cam; The curvatures of two adjacent first transmission surfaces are different; and / or The curvatures of two adjacent first transmission surfaces are different.

6. The arc extinguishing device for circuit breaker according to claim 4, characterized in that: The outer peripheral surface of the cam is provided with at least two first transmission surfaces, and the distances between each first transmission surface and the rotation center of the cam are different.

7. The arc extinguishing device for circuit breaker according to claim 4, characterized in that: The cam is provided with a second transmission surface, the rotation center of the cam is at an equal distance from each point on the second transmission surface, and when the second transmission surface contacts the lever, the nozzle of the insulating medium injector is closed; The cam is provided with a transition surface which smoothly transitions with the first transmission surface and the second transmission surface, and the lever is provided with a protrusion which matches with the transition surface.

8. The circuit breaker arc extinguishing device according to claim 1, characterized in that: The spraying direction of the insulating medium sprayer intersects with the moving direction of the moving contact; The moving contact and the stationary contact are both metal sheets. The moving contact is provided with a moving bending portion extending away from the stationary contact at one end close to the nozzle. The stationary contact is provided with a stationary bending portion extending away from the moving contact at one end close to the nozzle. The nozzle is arranged between the stationary bending portion and the moving bending portion.

9. The circuit breaker arc extinguishing device according to claim 1, characterized in that: An elastic reset member for driving the nozzle to reset is arranged inside the insulating medium injector.

10. The arc extinguishing device for circuit breaker according to claim 1, characterized in that: The insulating medium in the insulating medium injector is at least one of sulfur hexafluoride gas, helium gas and argon gas.

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