Longitudinal magnetic contact of alumina filling type vacuum circuit breaker

Abstract

The utility model provides an alumina filling type vacuum circuit breaker longitudinal magnetic contact, which belongs to the field of vacuum circuit breaker contact design and comprises a coil with a slotted area, a contact blade and an alumina filling block. The aluminum oxide filling block fills the slotted area of the coil and is fixedly connected with the coil; the length of the aluminum oxide filling block is not greater than that of the single slotted area, and the height is not greater than that of the single slotted area; and the width is not greater than the width of a single slotting area. The aluminum oxide filling blocks are used for enabling supporting force to exist between the different coils, short circuit caused by mutual contact between the different layers of coils is avoided, and meanwhile a conductive path is not changed. The mechanical performance of the contact is improved on the premise that an original conductive loop of the contact coil is not affected.

Description

Technical Field

[0001] The present application belongs to the field of vacuum circuit breaker contact design, and more specifically, relates to an alumina-filled vacuum circuit breaker longitudinal magnetic contact. Background Art

[0002] In order to enhance the longitudinal magnetic field of the longitudinal magnetic contact and improve the breaking capacity of the longitudinal magnetic contact, 1 / 2, 2 / 3 and 3 / 4 high-ratio coil longitudinal magnetic contacts are mostly used at this stage. This type of contact can significantly improve the longitudinal magnetic field, but due to its large slot length, its mechanical strength is low. Under the stress generated by closing the circuit, it may produce large deformation, causing the contact coil to short-circuit and fail to work normally. Utility Model Content

[0003] In response to the defects of the existing technology, the purpose of this application is to provide an alumina-filled vacuum circuit breaker longitudinal magnetic contact, which aims to solve the problem that the coil of the existing longitudinal magnetic contact will produce a large deformation under the stress generated by closing the circuit, causing the contact coil to short-circuit and fail to work normally.

[0004] To achieve the above-mentioned object, the present application provides an alumina-filled vacuum circuit breaker longitudinal magnetic contact, comprising: a guide rod, a coil in a slotted area, a contact piece, and an alumina filling block;

[0005] The alumina filling block fills the slotted area of the coil and is fixedly connected to the coil; the length of the alumina filling block is no longer than the length of a single slotted area, the height is no higher than the height of a single slotted area, and the width is no wider than the width of a single slotted area; the guide rod is located inside the coil and connected to the first end of the coil; and the contact piece is located at the tail end of the coil;

[0006] Alumina filler blocks are used to provide support between different coils to prevent short circuits between coils in different layers without changing the conductive path.

[0007] The contact pieces are used to provide axial pressure to the coil by contacting each other when closing the circuit.

[0008] Further preferably, the longitudinal magnetic contacts of the vacuum circuit breaker include: a 2 / 3 coil longitudinal magnetic contact, a 1 / 2 coil longitudinal magnetic contact and a 3 / 4 coil longitudinal magnetic contact.

[0009] Further preferably, the inner arc and outer arc lengths of the alumina filling block are respectively equal to the inner arc and outer arc lengths of a single slotted area, its width is the width of a single slotted area, and its height is the height of a single slotted area.

[0010] Further preferably, one side of the alumina filling block is fixedly connected to the coil by welding.

[0011] Further preferably, the coil is a copper coil.

[0012] Further preferably, the coils in the slotted area are arranged in multiple layers, the guide rod is connected to the head end of the first layer of coils, the middle layer of coils are connected head to tail; and the tail end of the last layer of coils is connected to the contact piece.

[0013] Further preferably, during the stress test, one longitudinal magnetic contact of the alumina-filled vacuum circuit breaker is placed upside down on top of another longitudinal magnetic contact of the alumina-filled vacuum circuit breaker; and the contact pieces in the two longitudinal magnetic contacts of the alumina-filled vacuum circuit breaker are adjacent.

[0014] In general, the above technical solutions conceived by this application have the following beneficial effects compared with the existing technologies:

[0015] The present application provides an alumina-filled longitudinal magnetic contact for a vacuum circuit breaker. Relying on the characteristics of low electrical conductivity and high mechanical strength of alumina, alumina is filled into the slotted area to improve the mechanical properties of the contact without affecting the original conductive circuit of the contact coil. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the 2 / 3 coil longitudinal magnetic contact structure provided in an embodiment of the present application;

[0017] Figure 2 This is a schematic diagram of the structure of a 2 / 3 coil longitudinal magnetic contact filled with alumina provided in an embodiment of the present application;

[0018] Figure 3 This is a schematic diagram of the alumina filling block provided in the embodiment of the present application. DETAILED DESCRIPTION

[0019] For ease of understanding, the English abbreviations and related technical terms involved in the embodiments of this application are explained and described below.

[0020] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0021] In order to solve the problem of poor mechanical strength of high-ratio coil contacts, the present application provides an alumina-filled vacuum circuit breaker longitudinal magnetic contact, which relies on the low electrical conductivity and high mechanical strength of alumina to improve the mechanical properties of the contact without affecting the original conductive circuit of the contact coil.

[0022] The embodiment of the present application takes the 2 / 3 coil longitudinal magnetic contact as an example. Figure 1As shown, the existing 2 / 3 coil longitudinal magnetic contact includes a guide rod 1 and a contact unit 2; the contact unit includes a coil 21 with a slotted area 22 and a contact piece 23; for the longitudinal magnetic contact in which the slotted area is not filled with alumina filling blocks, when closing the circuit, the contact pieces 23 of the two contact units first contact and provide a pressure along the axial direction of the guide rod to the coil 21. This pressure acts on the coil 21. If the coil is not filled with alumina, the coil will produce obvious deformation under a large pressure, causing the first layer of coil 211 and the second layer of coil 212 to contact each other, resulting in a short circuit, and the circuit breaker longitudinal magnetic contact cannot perform its normal function.

[0023] like Figure 2 As shown, the 2 / 3 coil longitudinal magnetic contact provided by the present application is filled with alumina filling blocks in the slot area. The alumina filling blocks are cast into a block arc 24 with a length equal to the coil slot, a height equal to the slot height, and a width equal to the slot width. Several alumina filling blocks are sequentially filled into the slot area and high-temperature welded to fix the alumina filling block structure between different layers of coils.

[0024] Alumina is a material with low electrical conductivity, magnetic permeability close to that of air, and high mechanical strength. If it is filled into the slotted area, when the coil is subjected to pressure, the alumina structure filled in the slotted area provides support between different coils, the stress is evenly distributed, and the coil will not be significantly deformed, thereby avoiding the short circuit problem after different layers of coils come into contact with each other; at the same time, the electrical conductivity of alumina itself is very low and will not change the original conductive path of the contact; therefore, the 2 / 3 coil longitudinal magnetic contact filled with alumina filling blocks has greater mechanical strength, and its original electromagnetic properties will not change; similarly, the mechanical strength of the 1 / 2 coil and 3 / 4 coil longitudinal magnetic contacts can also be improved by using alumina filling.

[0025] Table 1 shows the strain results of the 2 / 3 coil longitudinal magnetic contacts without alumina filling and with alumina filling under a certain load. The maximum deformation of the coil in the unfilled state is 3.1 mm, which is larger than the 3 mm spacing between the first layer coil 211 and the second layer coil 212. A short circuit will occur and the contacts will not work properly. The maximum deformation of the coil in the filled state is 0.3 mm, which is smaller than the 3 mm spacing between the first layer coil 211 and the second layer coil 212. No short circuit will occur and the contacts can work properly.

[0026] Table 1

[0027]

[0028] Size setting of the alumina filling block: Taking the 2 / 3 contact given in the embodiment of this application as an example, Figure 3As shown, the lengths of inner arc 241 and outer arc 242 are close to those of a single slot area, respectively, and their upper machining limits are smaller than those of a single slot area. Width 244 is close to the width of a single slot area, and its upper machining limit is smaller than that of a single slot area. The height 243 of the alumina filler block is close to the height of a single slot area, and its upper machining limit is smaller than that of a single slot area. In actual application, one side of the alumina filler block is high-temperature welded to the copper coil to form a fixed structure.

[0029] The following finite element mechanics simulation verification

[0030] Establish as Figure 2 The geometric model shown and the material parameters are as follows Table 2:

[0031] Table 2

[0032]

[0033] Fix the bottom surface 4 of the simulated 2 / 3 coil longitudinal magnetic contact model and apply a 3×10 7 The table shows that under the same load, the deformation of the contact coil filled with alumina is smaller, and the overall mechanical strength of the coil is higher, which verifies the reliability of the alumina-filled structure.

[0034] It should be understood that expressions such as "include" and "may include" used in this application indicate the existence of the disclosed functions, operations, or constituent elements, and do not limit one or more additional functions, operations, and constituent elements. In this application, terms such as "include" and / or "have" may be interpreted as indicating specific characteristics, numbers, operations, constituent elements, components, or combinations thereof, but may not be interpreted as excluding the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.

[0035] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense.

[0036] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. An alumina-filled vacuum circuit breaker longitudinal magnetic contact, characterized in that: include: Guide rods, coils in slotted areas, contact blades and alumina filler blocks; The alumina filling block fills the slotted area of the coil, and the alumina filling block is fixedly connected to the coil; the length of the alumina filling block is not longer than the length of a single slotted area, and the height is not higher than the height of a single slotted area; the width is not wider than the width of a single slotted area; the guide rod is located inside the coil and connected to the head end of the coil; the contact piece is located at the tail end of the coil.

2. The longitudinal magnetic contact of the alumina-filled vacuum circuit breaker according to claim 1, characterized in that: The longitudinal magnetic contacts of the vacuum circuit breaker include: 2 / 3 coil longitudinal magnetic contact, 1 / 2 coil longitudinal magnetic contact and 3 / 4 coil longitudinal magnetic contact.

3. The longitudinal magnetic contact of the alumina-filled vacuum circuit breaker according to claim 1 or 2, characterized in that: The inner arc and outer arc lengths of the alumina filling block are respectively equal to the inner arc and outer arc lengths of the single slotted area, the width thereof is the width of the single slotted area, and the height thereof is the height of the single slotted area.

4. The longitudinal magnetic contact of the alumina-filled vacuum circuit breaker according to claim 1 or 2, characterized in that: One side of the alumina filling block is fixedly connected to the coil by welding.

5. The longitudinal magnetic contact of the alumina-filled vacuum circuit breaker according to claim 1, characterized in that: The coil is a copper coil.

6. The longitudinal magnetic contact of the alumina-filled vacuum circuit breaker according to claim 1, characterized in that: The coils in the slotted area are arranged in multiple layers, the guide rod is connected to the head end of the first layer of coils, the head and tail of the middle layer of coils are connected; and the tail end of the last layer of coils is connected to the contact piece.

7. The longitudinal magnetic contact of the alumina-filled vacuum circuit breaker according to claim 1 or 6, characterized in that: During the stress test, an longitudinal magnetic contact of an alumina-filled vacuum circuit breaker is placed upside down on the longitudinal magnetic contact of another alumina-filled vacuum circuit breaker; the contact pieces in the longitudinal magnetic contacts of the two alumina-filled vacuum circuit breaker are adjacent.

Images