Normally open type vacuum contactor

Abstract

The invention discloses a normally open type vacuum contactor, and relates to the technical field of vacuum arc extinguishing. Comprising a vacuum chamber, the vacuum chamber comprises a static contact assembly and a moving contact assembly, the moving contact assembly comprises a moving contact and a moving pull rod, one end, facing a second end of the vacuum chamber, of the moving pull rod is provided with the moving contact through an insulation structure, and the other end of the moving pull rod penetrates through a pull rod penetrating hole of the vacuum chamber and is in sealed connection with the vacuum chamber through a corrugated pipe; a static contact of the static contact assembly is located on the side, close to the corrugated pipe, of the moving contact, in the natural state, under the action of the pressure difference inside and outside the vacuum cavity, the moving contact is kept in the opening state spaced from the static contact, and when the operating mechanism drives the moving contact assembly to be closed, the moving contact is closed. The moving contact moves towards the second end of the vacuum chamber to conduct the two static contacts and compress the corrugated pipe. Through the arrangement, the moving contact and the static contact can be in a normally open structure under the internal and external pressure difference of the vacuum chamber, the condition that the contact is adhered is prevented, and the structure is simple and more reliable.

Description

Technical Field

[0001] The invention relates to the technical field of vacuum arc extinguishing, in particular to a normally open vacuum contactor. Background Art

[0002] With the continuous development of the power industry and the improvement of environmental protection requirements, vacuum contactors are also developing towards a new contactor structure with high insulation performance, strong arc extinguishing ability, and little or even smaller volume. However, the moving contacts and static contacts in conventional vacuum contactors are generally set as normally closed structures. After working for a period of time, the contacts are prone to sticking, resulting in reduced arc extinguishing performance.

[0003] The Chinese patent with the authorization announcement number CN113410090B discloses a vacuum relay. When the electromagnetic coil is energized, the electromagnetic coil generates a magnetic field, pushing the moving iron core upward, compressing the opening spring, and at the same time pushing the connecting push rod upward, compressing the contact pressure spring, and the connecting push rod pushes the bellows upward to stretch, thereby pushing the moving contact upward to contact with the static contact to achieve closing. When the electromagnetic coil is de-energized, under the action of the opening spring, the moving iron core moves downward, and the elastic force of the opening spring separates the moving iron core and the static iron core, and the contact The tension of the pressure spring pushes the moving iron core downward, and the moving iron core drives the connecting push rod downward, so that the moving contact is separated from the static contact, so that the moving contact and the static contact are normally open, and the contact sticks. However, this design has a complex structure, and the opening spring needs to overcome the upward force of atmospheric pressure to separate the moving contact and the static contact, which has high requirements on the elasticity of the opening spring. After a period of use, the elasticity of the opening spring will weaken, so that the moving contact and the static contact cannot be stably opened and normally opened. The reliability is poor and cannot meet current needs. Summary of the invention

[0004] The object of the present invention is to provide a normally open vacuum contactor to solve the problems of complex structure and poor reliability of the existing normally open contact.

[0005] To achieve the above-mentioned purpose, a normally open vacuum contactor of the present invention adopts the following technical scheme: it includes a vacuum chamber, a first end of the vacuum chamber is provided with a static contact assembly relatively spaced apart, a second end of the vacuum chamber is provided with a moving contact assembly, the moving contact assembly includes a moving contact and a moving pull rod, the moving contact is installed on one end of the moving pull rod facing the second end of the vacuum chamber through an insulating structure, the other end of the moving pull rod passes through the pull rod through-hole of the vacuum chamber and is sealed and connected to the vacuum chamber through a bellows, the static contact of the static contact assembly is on the side of the moving contact close to the bellows, in a natural state, under the action of the pressure difference between the inside and outside of the vacuum chamber, the moving contact remains in an open state spaced apart from the static contact, and when the operating mechanism drives the moving contact assembly to close, the moving contact moves toward the second end of the vacuum chamber to conduct the two static contacts and compress the bellows.

[0006] Beneficial effects: The normally open vacuum contactor of the present invention improves the existing normally open contact structure. By setting a vacuum chamber and utilizing the fact that the air pressure in the vacuum chamber is lower than the air pressure outside the vacuum chamber, the moving contact and the static contact are normally open under the internal and external pressure difference. When the operating mechanism drives the moving contact assembly to close, the bellows will be compressed. After the operating mechanism is closed, the compression of the bellows will be released, and the moving contact and the static contact will be in the normally open state again. This arrangement will not cause the contact sticking, and has a simple structure and high reliability.

[0007] Preferably, the static contact assembly includes a static pull rod, which is sealed and connected to the wall of the vacuum chamber and passes through the vacuum chamber. The end of the static pull rod outside the vacuum chamber is a wiring terminal, and the end inside the vacuum chamber is connected to the static contact. The static contact is a cantilever structure and cantilevers to the closing movement path of the moving contact.

[0008] Beneficial effect: The static contact is set as a cantilever structure with a certain elastic deformation ability, and can be suspended to the closing movement path of the moving contact. When closing, the moving contact can be close to the static contact, with a simple structure and reliable contact.

[0009] Preferably, a stop structure is provided in the vacuum chamber on a side of the moving contact away from the bellows to stop the moving contact in the open position.

[0010] Beneficial effect: The stop structure can stop the moving contact in the open position, preventing the bellows from being subjected to a large atmospheric pressure.

[0011] Preferably, the stopping structure is a cavity wall at the first end of the vacuum chamber.

[0012] Beneficial effect: The position of the moving contact is restricted by the inner wall of the vacuum chamber, which is simple and easy to implement.

[0013] Preferably, the outer diameter of the bellows is larger than the inner diameter of the hole of the pull rod.

[0014] Beneficial effect: Under the action of atmospheric pressure, the bellows can withstand greater pressure, which can make the moving contact and the static contact more reliably normally open.

[0015] Preferably, a bellows shielding cover is further provided on the side of the bellows facing the stationary contact.

[0016] Beneficial effect: the static contact is close to the end of the bellows, and the provision of a shielding cover can better achieve insulation shielding between the bellows and the static contact.

[0017] Preferably, the insulating structure comprises a plurality of insulating pads sleeved on the movable rod, all the insulating pads cover the outer surface of the movable rod, and the movable contact is clamped and fixed between two adjacent insulating pads and insulated from the movable rod.

[0018] Beneficial effects: the insulating pads can be installed according to the length of the moving pull rod, which has good adaptability; all the insulating pads cover the outer surface of the moving pull rod, which will provide better insulation for the moving contact and the moving pull rod.

[0019] Preferably, the insulating spacer is in a stepped shape with a ring platform in the middle of one side, and the moving contact is sleeved on the outer side of the ring platform of the corresponding insulating spacer to maintain insulation isolation from the moving pull rod.

[0020] Beneficial effect: the moving contact can be sleeved on the outer side of the ring platform of the insulating pad to maintain insulation isolation from the moving pull rod, the insulation will be better, the structure is simple and more reliable.

[0021] Preferably, the static contact is welded on the static tie rod.

[0022] Beneficial effect: The static contact can be connected to the static pull rod more stably, firmly and reliably. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of Example 1 of a normally open vacuum contactor of the present invention.

[0024] In the figure: 1. cover plate; 2. porcelain shell; 3. static conductive rod; 4. static contact; 5. insulating pad; 6. moving pull rod; 7. moving contact; 8. connecting rod; 9. bellows; 10. bellows shielding cover; 11. electromagnetic mechanism; 12. vacuum chamber; 13. pull rod perforation. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, that is, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention.

[0027] It should be noted that relational terms such as "first" and "second" that may appear are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, terms such as "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also other elements that are not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by a sentence such as "comprises a..." does not exclude the existence of other identical elements in the process, method, article or device that includes the element.

[0028] Specific embodiment 1 of a normally open vacuum contactor of the present invention:

[0029] like Figure 1 As shown, it includes a vacuum chamber 12, which is formed by sealing a ceramic shell 2 and a cover plate 1. Two pairs of static contact assemblies are relatively spaced apart at the lower end of the vacuum chamber 12. The static contact assembly includes a static contact 4 and a static conductive rod 3. The static conductive rod 3 is sealed and connected to the bottom of the ceramic shell 2 by vacuum brazing and passes through the cavity wall of the vacuum chamber 12. A protruding structure is provided on the static conductive rod 3, and a welding hole matching the protruding structure is provided on the static contact 4, which is welded together with the protruding structure on the static conductive rod 3 through the welding hole.

[0030] The upper and lower ends are Figure 1In the direction shown, the lower end corresponds to the first end of the vacuum chamber 12, and the upper end corresponds to the second end of the vacuum chamber 12; a moving contact assembly is provided at the upper end of the vacuum chamber 12, and the moving contact assembly includes a moving contact 7 and a moving pull rod 6. The moving contact 7 is installed at the lower end of the moving pull rod 6 through an insulating structure, and the upper end passes through the pull rod through hole 13 of the vacuum chamber 12 and is sealed and connected to the vacuum chamber 12 through a bellows 9. The moving contact 7 is arranged below the static contact 4, and the static contact 4 is a cantilever structure and cantilevers to the closing movement path of the moving contact 7.

[0031] The insulating structure includes a plurality of insulating pads 5 sleeved on the movable pull rod 6, all of the insulating pads 5 cover the outer surface of the movable pull rod 6, the insulating pads 5 are stepped with a ring platform in the middle of one side, and the movable contact 7 is sleeved on the outer side of the ring platform of the corresponding insulating pad 5 to maintain insulation isolation from the movable pull rod 6; in the vacuum chamber 12, on the side of the movable contact 7 away from the bellows 9, the cavity wall at the bottom of the vacuum chamber 12 is used to stop the movable contact 7 in the open position to prevent the bellows from being subjected to a large atmospheric pressure; the upper end of the movable pull rod 6 is welded to the connecting rod 8, and a bellows 9 is provided at one end of the connecting rod 8, the outer diameter of the bellows 9 is larger than the inner diameter of the pull rod through hole 13, and the other end of the connecting rod 8 is vacuum brazed on the pull rod through hole 13, and a bellows shielding cover 10 is provided on the side of the bellows 9 facing the static contact 4. The provision of the bellows shielding cover 10 can better achieve insulation shielding between the bellows 9 and the static contact 4.

[0032] An operating mechanism is provided above the cover plate 1, and the operating mechanism is an electromagnetic mechanism 11. When the electromagnetic mechanism 11 is turned on, the connecting rod 8 and the moving pull rod 6 are stretched upward, so that the moving contact 7 and the static contact 4 can be closed, and the bellows 9 can be compressed to store energy. After closing the electromagnetic mechanism 11, under the rebound effect of the bellows 9 and the internal and external pressure difference, the moving contact 7 is pushed downward to separate the moving contact 7 and the static contact 4 to extinguish the arc. At the same time, under the internal and external pressure difference of the vacuum chamber 12, the moving contact 7 and the static contact 4 are in a normally open structure.

[0033] In Example 1, the static contact 4 and the moving contact 7 are arranged in a vacuum chamber 12 formed by the porcelain shell 2 and the cover plate 1, so that the air pressure in the vacuum chamber 12 is lower than the external air pressure. The moving contact 7 is arranged below the static contact 4. Under the action of the internal and external pressure difference, a normally open structure can be presented. At the same time, when the electromagnetic mechanism 11 drives the moving contact assembly to close, the bellows 9 will be compressed. After the electromagnetic mechanism 11 is closed, the compression of the bellows 9 is released, and the moving contact 7 and the static contact 4 will be in the normally open state again. In this way, the moving contact 7 and the static contact 4 can be in the normally open state under the internal and external pressure difference, and the contact sticking will not occur. The structure is simple, easy to implement, and more reliable.

[0034] Embodiment 2 of a normally open vacuum contactor of the present invention, in this embodiment, the stop structure can be a stop block, which is arranged below the moving contact in the porcelain shell, and the rest is the same as embodiment 1, which will not be described in detail. In other embodiments, the stop structure can also be omitted, and an operating mechanism can be used to control the moving contact to remain in the open position.

[0035] Embodiment 3 of a normally open vacuum contactor of the present invention, in this embodiment, the outer diameter of the bellows can be equal to the inner diameter of the tie rod through hole, and the rest is the same as embodiment 1 and will not be repeated. In other embodiments, the outer diameter of the bellows can also be smaller than the inner diameter of the tie rod through hole.

[0036] Embodiment 4 of a normally open vacuum contactor of the present invention, in this embodiment, the static contact may not be a cantilever structure, but the static contact is set as an inclined rod facing the middle of the vacuum chamber. At this time, the moving contact is set as an isosceles trapezoidal structure. When closing the circuit, the moving contact can be connected to the static contact through two waists. The rest is the same as Embodiment 1 and will not be repeated.

[0037] Embodiment 5 of a normally open vacuum contactor of the present invention, in this embodiment, the insulating structure can be an insulating coating, the insulating coating is first applied to the outside of the moving rod, and then the moving contact is injection molded and fixed on the moving rod. The rest is the same as embodiment 1 and will not be repeated.

[0038] Embodiment 6 of a normally open vacuum contactor of the present invention, in this embodiment, the static contact may not be welded to the static pull rod, but may be directly set as an integrated L-shaped structure, and the rest is the same as embodiment 1 and will not be repeated.

[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. The patent protection scope of the present invention shall be based on the claims. All equivalent structural changes made using the contents of the description and drawings of the present invention should also be included in the protection scope of the present invention.

Claims

1. A normally open vacuum contactor, comprising a vacuum chamber (12), a first end of the vacuum chamber (12) being provided with a stationary contact assembly at a relative interval, a second end of the vacuum chamber (12) being provided with a moving contact assembly, the moving contact assembly comprising a moving contact (7) and a moving pull rod (6), one end of the moving pull rod (6) facing the second end of the vacuum chamber (12) being provided with the moving contact (7) via an insulating structure, the other end of the moving pull rod (6) passing through a pull rod through hole (13) of the vacuum chamber (12) and being sealed and connected to the vacuum chamber (12) via a bellows (9), characterized in that: The stationary contact (4) of the stationary contact assembly is located on the side of the moving contact (7) close to the bellows (9). In a natural state, under the action of the pressure difference between the inside and outside of the vacuum chamber (12), the moving contact (7) is maintained in an open state spaced apart from the stationary contact (4). When the operating mechanism (11) drives the moving contact assembly to close, the moving contact (7) moves toward the second end of the vacuum chamber (12) to conduct the two stationary contacts (4) and compress the bellows (9).

2. The normally open vacuum contactor according to claim 1, characterized in that: The static contact assembly comprises a static pull rod (3), wherein the static pull rod (3) is sealedly connected to the wall of the vacuum chamber (12) and passes through the vacuum chamber (12); one end of the static pull rod (3) located outside the vacuum chamber (12) is a wiring terminal, and the other end located inside the vacuum chamber (12) is connected to the static contact (4); the static contact (4) is a cantilever structure and is cantilevered to the closing movement path of the moving contact (7).

3. The normally open vacuum contactor according to claim 1, characterized in that: A stop structure is provided in the vacuum chamber (12) on a side of the moving contact (7) away from the bellows (9) to stop the moving contact (7) in an open position.

4. The normally open vacuum contactor according to claim 3, characterized in that: The stopping structure is a cavity wall at the first end of the vacuum chamber (12).

5. The normally open vacuum contactor according to claim 1, characterized in that: The outer diameter of the bellows (9) is greater than the inner diameter of the pull rod through hole (13).

6. The normally open vacuum contactor according to claim 1, characterized in that: A bellows shielding cover (10) is also provided on the side of the bellows (9) facing the stationary contact (4).

7. The normally open vacuum contactor according to any one of claims 1 to 6, characterized in that: The insulating structure comprises a plurality of insulating pads (5) sleeved on the movable pull rod (6), all the insulating pads (5) cover the outer surface of the movable pull rod (6), and the movable contact (7) is clamped and fixed between two adjacent insulating pads (5) and insulated from the movable pull rod (6).

8. The normally open vacuum contactor according to claim 7, characterized in that: The insulating pad (5) is in a stepped shape with a ring platform in the middle of one side, and the moving contact (7) is sleeved on the outer side of the ring platform of the corresponding insulating pad (5) to maintain insulation isolation from the moving pull rod (6).

9. The normally open vacuum contactor according to claim 2, characterized in that: The static contact (4) is welded to the static pull rod (3).

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