Main conductive cylinder of alternating-current circuit breaker and manufacturing method of main conductive cylinder

Abstract

The invention discloses an alternating current circuit breaker main conductive cylinder and a manufacturing method thereof, the main conductive cylinder comprises a main body structure, a conductive layer and an external heat dissipation structure, the main body structure is obtained through plate rolling welding, and the conductive layer is deposited on the outer surface of the main body structure through an additive manufacturing mode; and an external heat dissipation structure is further deposited on the outer surface of the conductive layer in an additive manufacturing mode. The main conductive cylinder has high mechanical strength and electrical conductivity and thermal conductivity, and can meet the through-flow and heat dissipation requirements of the main conductive cylinder of the alternating current circuit breaker.

Description

Technical Field

[0001] The invention belongs to the field of metal processing and manufacturing, in particular to the field of AC circuit breakers, and relates to a main conductive cylinder of an AC circuit breaker and a manufacturing method thereof. Background Art

[0002] With the continuous development of my country's power system, grid voltage levels are constantly increasing, and grid capacity is also increasing. The increasing demand for electricity places higher demands on the grid's transmission capacity. Circuit breakers play a crucial role in ensuring safe and stable operation during power transmission and conversion. As a core component in the power system, circuit breakers can cut off the system's operating current during normal operation. They can also work with other protective devices to quickly and reliably cut off the current blocking the system when a power system fault occurs, reducing the scope of the fault. Because circuit breakers must carry the system's operating current when normally conducting, the rated current increases with the continuous increase in power system capacity, causing serious temperature rise problems for the circuit breakers. This temperature rise is also a bottleneck in circuit breaker development. Excessive temperature rise can lead to insulation degradation in various internal structures of the circuit breaker, reducing mechanical strength, and limiting the trend towards smaller circuit breakers with larger rated currents.

[0003] The main conductive cylinder of a circuit breaker is a crucial component, supporting the overall structure and carrying the operating current. Because it's located on the outermost edge of the circuit breaker and is relatively large, it's typically manufactured using casting. Due to mechanical strength requirements, the material used is typically high-strength aluminum alloy, which has poor electrical and thermal conductivity, leading to significant temperature rise during operation. Casting also results in high costs, impacting the cost of the circuit breaker. When AC current flows, the current concentrates on the conductor's surface, reducing the current density at the center. Traditional methods, such as casting, restrict the selection of a single material and fail to address both strength and electrical and thermal conductivity requirements.

[0004] Therefore, how to improve the electrical conductivity and thermal conductivity of the main conductive cylinder of the circuit breaker while ensuring the mechanical strength of the main conductive cylinder and reducing the production cost is a technical problem that needs to be solved urgently. Summary of the Invention

[0005] In order to overcome the above problems, the present invention proposes a main conductive cylinder for an AC circuit breaker and a manufacturing method thereof, wherein the main conductive cylinder includes a main structure, a conductive layer and an external heat dissipation structure. The main structure is obtained by coil welding, and the conductive layer is deposited on the outer surface of the main structure by additive manufacturing. The external heat dissipation structure is further deposited on the outer surface of the conductive layer by additive manufacturing. The main structure of the main conductive cylinder plays a supporting role and is made of high-strength aluminum alloy to ensure mechanical strength requirements; the conductive layer is responsible for the flow of current and is processed using pure aluminum as raw material to reduce working heat; the external heat dissipation structure is processed using pure aluminum as raw material to increase the heat dissipation area and improve the overall heat dissipation capacity. The integrated processing of dissimilar metals is achieved by combining coil welding with additive manufacturing. The obtained main conductive cylinder has high mechanical strength, takes into account both electrical conductivity and thermal conductivity, and realizes the overall design and forming of dissimilar metals. The design and processing are flexible and free, which can effectively reduce production costs and improve material utilization, thereby completing the present invention.

[0006] Specifically, the purpose of the present invention is to provide the following aspects:

[0007] In a first aspect, a main conductive cylinder of an AC circuit breaker is provided, wherein the main conductive cylinder includes a main structure, a conductive layer and an external heat dissipation structure. The main structure is obtained by rolling welding, the conductive layer is deposited on the outer surface of the main structure by an additive manufacturing method, and the external heat dissipation structure is deposited on the outer surface of the conductive layer by an additive manufacturing method.

[0008] In a second aspect, a method for preparing the main conductive cylinder in the first aspect is provided, the method comprising:

[0009] Step 1: Establish a main conductive cylinder model, which includes a main structure model, a conductive layer model, and an external heat dissipation structure model;

[0010] Step 2: Prepare the main structure by coil welding according to the main structure model;

[0011] Step 3: depositing a conductive layer on the outer surface of the main structure by additive manufacturing according to the conductive layer model;

[0012] Step 4: According to the external heat dissipation structure model, an external heat dissipation structure is deposited on the outer surface of the conductive layer by additive manufacturing to obtain the main conductive cylinder.

[0013] The beneficial effects of the present invention include:

[0014] (1) The main conductive cylinder of the AC circuit breaker provided by the present invention is manufactured by combining plate rolling welding with additive manufacturing. On the basis of meeting the structural strength, the current carrying capacity of the main conductive cylinder is improved, and the heat dissipation is increased by setting an external heat dissipation structure, which effectively reduces the temperature rise problem of the circuit breaker. It is of great significance to the manufacture and use of large-capacity AC circuit breakers.

[0015] (2) The main conductive cylinder of the AC circuit breaker provided by the present invention has high strength, the pure aluminum conductive layer on the outer surface has high conductivity and strong current carrying capacity, the external heat dissipation structure effectively improves the heat dissipation capacity, and the combination of sheet rolling technology and additive manufacturing technology effectively improves material utilization and reduces production costs.

[0016] (3) The main conductive cylinder of the AC circuit breaker provided by the present invention has a supporting main structure and is manufactured by rolling and welding, which reduces processing time; the conductive layer is made of pure aluminum as the material and deposited by additive manufacturing, and the thickness is guaranteed to be above the aluminum skin depth, effectively reducing the current impedance and reducing heat generation; the external heat dissipation structure is made of pure aluminum as the material and deposited by additive manufacturing, ensuring that heat dissipation is increased on the basis of thermal conductivity, effectively increasing the heat dissipation of the circuit breaker and reducing the temperature rise of the circuit breaker.

[0017] (4) The preparation method of the main conductive cylinder of the AC circuit breaker provided by the present invention applies different materials to the main conductive cylinder structure through different processing methods such as plate rolling welding and additive manufacturing, and uses high-strength materials such as aluminum alloy to ensure the mechanical strength of the main structure; uses pure aluminum material to process the conductive layer and the external heat dissipation structure through additive manufacturing to ensure the current flow of the conductive layer and the heat dissipation capacity of the heat dissipation fins; gives full play to the characteristics of different materials, ensures and improves the performance indicators of the main conductive cylinder of the circuit breaker, and at the same time, improves the overall material utilization rate and effectively reduces the production cost, which is of great significance to the processing and manufacturing of circuit breakers. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Various other advantages and benefits of the present invention will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The drawings in the specification are intended only to illustrate preferred embodiments and are not to be construed as limiting the present invention. It is apparent that the drawings described below are merely some embodiments of the present invention, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0019] In the attached figure:

[0020] Figure 1 A schematic diagram of the structure of the main conductive cylinder of an AC circuit breaker according to a preferred embodiment of the present invention is shown;

[0021] Figure 2A front view of a main conductive cylinder of an AC circuit breaker according to a preferred embodiment of the present invention is shown;

[0022] Figure 3 A bottom view of a main conductive cylinder of an AC circuit breaker according to a preferred embodiment of the present invention is shown;

[0023] Figure 4 A side view of a main conductive cylinder of an AC circuit breaker according to a preferred embodiment of the present invention is shown;

[0024] Figure 5 A slicing trajectory diagram of the outer surface of the main structure according to a preferred embodiment of the present invention is shown.

[0025] Reference numerals

[0026] 1- Main structure;

[0027] 2- conductive layer;

[0028] 3-External heat dissipation structure;

[0029] 4- support member;

[0030] 5- heat dissipation channel;

[0031] 6- Slice trajectory. DETAILED DESCRIPTION

[0032] The following will refer to the attached Figures 1 to 5 Specific embodiments of the present invention will now be described in greater detail. Although specific embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention may be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to facilitate a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0033] It should be noted that certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that technicians may use different nouns to refer to the same component. This specification and claims do not use the difference in nouns as a way to distinguish components, but use the difference in the functions of the components as the criterion for distinction. As mentioned throughout the specification and claims, "including" or "comprising" is an open term, so it should be interpreted as "including but not limited to". The subsequent description of the specification is a preferred embodiment of the present invention, but the description is based on the general principles of the specification and is not intended to limit the scope of the invention. The scope of protection of the present invention shall be as defined in the attached claims.

[0034] In the description of the present invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front," and "rear" and the like, indicating positions or locations, are based on the operating state of the present invention and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0035] To facilitate understanding of the embodiments of the present invention, further explanation will be given below using specific embodiments as examples in conjunction with the accompanying drawings, and the accompanying drawings do not constitute a limitation on the embodiments of the present invention.

[0036] On the one hand, according to the present invention, a main conductive cylinder of an AC circuit breaker is provided, which includes a main structure 1, a conductive layer 2 and an external heat dissipation structure 3. The main structure 1 is obtained by coil welding, and the conductive layer 2 is deposited on the outer surface of the main structure 1 by an additive manufacturing method, and the external heat dissipation structure 3 is further deposited on the outer surface of the conductive layer 2 by an additive manufacturing method.

[0037] According to the present invention, the main structure 1 is used to support the structural strength, the conductive layer 2 is used to reduce the current impedance to reduce heat generation, and the external heat dissipation structure 3 is used to increase the heat dissipation area of ​​the main conductive cylinder to improve the heat dissipation capacity.

[0038] Furthermore, by combining different processing methods, different materials can be connected in the same structure, giving full play to the performance of different materials to meet the actual needs of different components, significantly improving the comprehensive performance of the circuit breaker main conductive cylinder, reducing production costs, and shortening the production cycle.

[0039] In the present invention, the main structure 1 is in a hollow cylindrical shape and is made of high-strength aluminum alloy through rolling and welding to meet the mechanical strength requirements of the main structure. The aluminum alloy is preferably 6061 aluminum alloy or 7075 aluminum alloy.

[0040] The thickness of the aluminum alloy plate is the wall thickness of the main structure 1, the length of the aluminum alloy plate is the circumference of the cross section of the main structure 1, and the width of the aluminum alloy plate is the length of the main structure 1. During welding, the width ends of the aluminum alloy plate are butt-jointed and clamped into a cylindrical shape for operation.

[0041] According to the present invention, the dimensions of the main structure 1 are the dimensions commonly used in the market, with a length of 800-1000 mm, an outer diameter of 1000-1100 mm, and a wall thickness of 20-40 mm; for example, the length is 910 mm, the outer diameter is 1060 mm, and the wall thickness is 30 mm.

[0042] According to the present invention, the conductive layer 2 is deposited on the outer surface of the main structure 1 by additive manufacturing. The cross-sectional shape of the conductive layer 2 is the same as that of the main structure 1 , and the length of the conductive layer 2 is the same as that of the main structure 1 .

[0043] According to the present invention, when an alternating current passes through a metal conductor, the current will concentrate on the surface of the conductor rather than being evenly distributed in the conductor cross section. This phenomenon of uneven distribution of alternating current is called the skin effect, where the depth of the skin effect can be obtained by the following formula:

[0044]

[0045] Where δ is the skin depth of the skin effect, ω is the AC frequency, σ is the electrical conductivity of the conductor, and μ is the magnetic permeability of the conductor.

[0046] For a given conductor material and AC frequency, the skin depth is constant. The skin depth under current flow is determined based on the conductivity and magnetic permeability of the conductive layer 2 material and the AC frequency. This skin depth is the thickness of the conductive layer 2. Typically, the thickness of the conductive layer 2 is 10-15 mm, for example, 12 mm.

[0047] According to the present invention, the conductive layer 2 is preferably made of pure aluminum, which ensures electrical conductivity and improves current carrying capacity to reduce heat generation.

[0048] According to the present invention, the external heat dissipation structure 3 is deposited on the outer surface of the conductive layer 2 by additive manufacturing. The shape of the heat dissipation structure is based on the cylindrical structure of the main structure 1 and the conductive layer 2, and is designed as a series of annular heat dissipation fins arranged along the axial direction. The individual heat dissipation fins are deposited layer by layer on the outer surface of the conductive layer 2. Preferably, the external heat dissipation structure 3 is provided with a notch at the bottom to facilitate the installation of the support member, that is, the external heat dissipation structure 3 is approximately annular in shape. It can be understood that the cross section of the external heat dissipation structure 3 is a ring with a notch, which is arranged axially along the surface of the conductive layer 2, and the notch is located at the bottom of the conductive layer 2, as shown in FIG. Figure 1 、 Figure 2 、 Figure 3 and Figure 4 shown.

[0049] Furthermore, if Figure 4 As shown, the corresponding angle θ at the bottom notch of the external heat dissipation structure 3 is 70° to 90°, accounting for about 20% to 25% of the complete circumference. For example, the angle θ at the bottom notch of the external heat dissipation structure 3 is 80°, accounting for 22.2% of the complete circumference.

[0050] Furthermore, the external heat dissipation structures 3 are evenly distributed along the outer surface of the conductive layer 2 , and the plurality of external heat dissipation structures 3 effectively dissipate the heat generated by the flowing current.

[0051] In the present invention, the cross-section of the external heat dissipation structure 3 perpendicular to the extension direction of the main structure 1 is a regular shape such as a triangle or an irregular shape, preferably a regular shape that is easy to process, such as a triangle. The triangular fin shape not only reduces the amount of material used, but also helps air flow, thereby improving the heat dissipation effect.

[0052] Among them, such as Figure 2 As shown, taking a triangle as an example, the side length S where the bottom of the external heat dissipation structure 3 meets the main structure 1, i.e., the bottom width of a single external heat dissipation structure 3, is 40-50 mm, and the height H where the triangle vertex is perpendicular to the main structure 1, i.e., the height of a single external heat dissipation structure 3, is 70-100 mm. For example, the side length S where the bottom of the external heat dissipation structure 3 meets the main structure 1 is 45 mm, and the height H is 80 mm. A wider external heat dissipation structure 3 can provide more heat dissipation area, while a narrower external heat dissipation structure 3 helps reduce the amount of material used. The gaps between the external heat dissipation structures 3 help air flow through the fins, thereby improving the heat dissipation effect. The design of the external heat dissipation structure 3 also takes into account the manufacturing process, cost, and ease of installation. Within the above-mentioned size range, the selected design parameters are not only low-cost but also have good heat dissipation effect.

[0053] In the present invention, the distance L between the central axes of two adjacent external heat dissipation structures 3, that is, the fin distance between two adjacent external heat dissipation structures 3, is 40-50 mm, for example, 45 mm.

[0054] The smaller the spacing between the external heat dissipation structures 3, the larger the heat dissipation area, which can more effectively conduct heat and improve heat dissipation efficiency. However, if the spacing is too small, the manufacturing cost will increase; on the contrary, if the spacing is too large, the heat dissipation area will decrease and the heat dissipation efficiency will decrease. It is more appropriate to be within the above range.

[0055] According to the present invention, the external heat dissipation structure 3 is preferably made of pure aluminum to ensure heat dissipation capability.

[0056] In this invention, an external heat dissipation structure 3 is directly deposited outside the main structure 1 and conductive layer 2 through additive manufacturing. This integrated structure 3 and conductive layer 2 effectively avoid air gaps created by connecting multiple components, improving overall heat dissipation. Compared to casting, this method offers greater flexibility in shape design and eliminates defects such as pores and cracks. Using pure aluminum as raw material, it boasts high thermal conductivity, ensuring excellent heat dissipation.

[0057] Preferably, a heat dissipation channel 5 is provided on the surface of the cylinder formed by the main structure 1, the conductive layer 2 and the external heat dissipation structure 3. The heat dissipation channel 5 is used to dissipate part of the heat from the inside of the main conductive cylinder by air convection, and form a heat circulation channel for the air to ensure the overall heat dissipation capacity. The heat dissipation channels 5 are 2 to 6 in number and are symmetrically distributed on the left and right sides of the cylinder formed by the main structure 1, the conductive layer 2 and the external heat dissipation structure 3; preferably, the heat dissipation channels 5 are 2 in number and are symmetrically distributed on the upper end of the cylinder formed by the main structure 1, the conductive layer 2 and the external heat dissipation structure 3, as shown in FIG. Figure 1 shown.

[0058] In the present invention, the heat dissipation channel 5 is not limited to any shape, and is preferably a rectangle that is easy to process, with a size of (500-600) mm×(80-120) mm, for example, 500 mm×100 mm.

[0059] In the present invention, Figure 3 As shown, the main conductive cylinder also includes a support member 4, which is used to support the cylinder formed by the main structure 1, the conductive layer 2 and the external heat dissipation structure 3. The support member 4 is arranged at the bottom of the conductive layer 2, specifically at the bottom of the external heat dissipation structure 3 connected to the conductive layer 2, preferably 4, evenly distributed at the bottom of the conductive layer 2.

[0060] On the other hand, according to the method for preparing the main conductive cylinder according to the first aspect of the present invention, the method comprises:

[0061] Step 1: Establish a main conductive cylinder model, which includes a main structure 1 model, a conductive layer 2 model, and an external heat dissipation structure 3 model;

[0062] Step 2: Prepare the main structure 1 by coil welding according to the main structure 1 model;

[0063] Step 3: According to the conductive layer 2 model, a conductive layer 2 is deposited on the outer surface of the main structure 1 by additive manufacturing;

[0064] Step 4: According to the model of the external heat dissipation structure 3, the external heat dissipation structure 3 is deposited on the outer surface of the conductive layer 2 by additive manufacturing to obtain the main conductive cylinder.

[0065] Specifically:

[0066] In step 1, the size of the main structure 1 model is the size commonly used in the market, with a length of 800-1000 mm, an outer diameter of 1000-1100 mm, and a wall thickness of 20-40 mm; for example, the length is 910 mm, the outer diameter is 1060 mm, and the wall thickness is 30 mm.

[0067] In step 1, the conductive layer 2 model is coated on the outer surface of the main structure 1 model. Its cross-sectional shape is the same as that of the main structure 1 model, and the conductive layer 2 model is the same length as that of the main structure 1 model. The skin depth under the flowing current is determined based on the electrical conductivity, magnetic permeability, and AC frequency of the conductive layer 2 material, thereby determining the thickness of the conductive layer 2 model. Typically, the thickness of the conductive layer 2 model is 10 to 15 mm, for example, 12 mm.

[0068] In step 1, the external heat dissipation structure 3 models are evenly distributed along the outer surface of the conductive layer 2 model; the central axis spacing L between the external heat dissipation structure 3 models is 40 to 50 mm, for example, 45 mm.

[0069] In step 2, the coil welding is preferably performed with a high-strength aluminum alloy, and the aluminum alloy is preferably selected from 6061 aluminum alloy or 7075 aluminum alloy.

[0070] In step 3, the following steps are preferably included:

[0071] Step 3-1, using the outer surface of the main structure 1 as a reference plane, determine the slice model of the conductive layer 2;

[0072] Step 3-2: Based on the conductive layer 2 model and the slice model of step 3-1, perform path planning and generate a corresponding additive manufacturing program;

[0073] In step 3-3, the main structure 1 is calibrated, and deposition is performed based on the additive manufacturing procedure described in step 3-2 to obtain the conductive layer 2.

[0074] In step 3-1, the outer surface of the main structure 1 is used as the reference surface, such as Figure 5 As shown, the conductive layer 2 model is sliced ​​in layers in the slicing software to obtain a slice model of the conductive layer 2. The slicing track 6 of the slicing model is a series of concentric circles with a slice thickness as a spacing; the slice thickness is 2 to 3 mm, usually 2 mm.

[0075] In step 3-2, the conductive layer 2 model and the slice model of the conductive layer 2 are imported into the path planning software, and the melting interval is set to 2 to 3 mm, such as 3 mm.

[0076] Furthermore, taking the preparation of the conductive layer 2 from pure aluminum as an example, based on its AC current-related parameters, the AC welding current parameters are set to 40-60 Hz, peak current to 180-210 A, base current to 80-110 A, and duty cycle to 45-55%; the travel speed is 1.5-2.5 mm / s, the wire feed speed is 1.5-2.5 m / min, the arc length is 4-6 mm, and the argon flow rate is 15-20 L / min. For example, the AC welding current parameters are set to 50 Hz, peak current to 200 A, base current to 100 A, and duty cycle to 50%; the travel speed is 2 mm / s, the wire feed speed is 2 m / min, the arc length is 5 mm, and the argon flow rate is 18 L / min.

[0077] In step 3-3, the central axis of the main structure 1 is used as the rotation axis, the outer surface of the main structure 1 is used as the reference plane, and the slices and layers are all parallel to the reference plane.

[0078] In step 3-3, taking the preparation of the conductive layer 2 from pure aluminum as an example, a pure aluminum wire with a diameter between 1 and 1.4 mm, for example, 1.2 mm, is selected as a raw material for deposition processing, thereby producing a high-quality conductive layer 2.

[0079] In step 3-3, before additive manufacturing, the main structure 1 is preheated at 80-120° C., such as 100° C., to improve deposition quality.

[0080] In step 3-3, additive manufacturing (AM) leverages its advantages of high deposition efficiency, high material utilization, and low cost. This processing method results in high heat input and a wide impact area, resulting in the conductive layer 2 exhibiting typical coarse columnar grains. This effectively increases the electrical conductivity of the pure aluminum conductive layer 2, thereby enhancing its current carrying capacity.

[0081] Furthermore, when alternating current passes through a conducting conductor, a skin effect occurs, causing the current to concentrate on the conductor's surface, resulting in a decrease in current density at the conductor's center, affecting the conductor's effective resistance and current distribution. Through additive manufacturing, a conductive layer 2 made of pure aluminum with a skin depth is deposited on the outside of the main structure 1. The aluminum alloy of the main structure 1 ensures structural strength, while the processing of the conductive layer 2 reduces resistance and increases current flow capacity. Traditional casting or machining methods are difficult to achieve by combining dissimilar metals in a cylindrical structure.

[0082] In step 4, the following steps are preferably included:

[0083] Step 4-1, using the outer surface of the conductive layer 2 as a reference plane, determine a slice model of the external heat dissipation structure 3;

[0084] Step 4-2, based on the external heat dissipation structure 3 model and the slice model of step 4-1, path planning is performed to generate a corresponding additive manufacturing program;

[0085] In step 4-3, the main structure 1 including the conductive layer 2 is calibrated, and deposition is performed based on the additive manufacturing procedure described in step 4-2 to obtain the external heat dissipation structure 3.

[0086] In step 4-1, the outer surface of the conductive layer 2 is used as the reference plane, and the external heat dissipation structure 3 model is layered and sliced ​​in the slicing software to obtain a slice model of the external heat dissipation structure 3. The slicing trajectory of the slicing model is a series of concentric circles with a slice thickness as the spacing; the slice thickness is 2 to 3 mm, usually 2 mm.

[0087] In step 4-2, the external heat dissipation structure 3 model and the slice model of the external heat dissipation structure 3 are imported into the path planning software, and the melting interval is set to 2 to 3 mm, such as 3 mm.

[0088] Furthermore, taking the external heat dissipation structure 3 made of pure aluminum as an example, based on its AC current-related parameters, the AC welding current parameters are set to 40-60 Hz, peak current to 180-210 A, base current to 80-110 A, and duty cycle to 45-55%; the travel speed is 1.5-2.5 mm / s, the wire feed speed is 1.5-2.5 m / min, the arc length is 4-6 mm, and the argon flow rate is 15-20 L / min. For example, the AC welding current parameters are set to 50 Hz, peak current to 200 A, base current to 100 A, and duty cycle to 50%; the travel speed is 2 mm / s, the wire feed speed is 2 m / min, the arc length is 5 mm, and the argon flow rate is 18 L / min.

[0089] In step 4-3, the central axis of the main structure 1 is used as the rotation axis, the outer surface of the conductive layer 2 is used as the reference plane, and the slices and layers are all parallel to the reference plane.

[0090] In step 4-3, taking the preparation of the external heat dissipation structure 3 using pure aluminum as an example, pure aluminum wire with a diameter between 1 and 1.4 mm, for example, 1.2 mm, is selected as the raw material to produce a high-quality external heat dissipation structure 3.

[0091] In step 4-3, before additive manufacturing, the main structure 1 and the deposited conductive layer 2 are preheated at 80-120° C., such as 100° C., to improve deposition quality.

[0092] In step 4-3, the external heat dissipation structure 3 is deposited directly on the outside of the conductive layer 2 using additive manufacturing. This integrated structure effectively avoids air gaps created by connecting multiple components, improving overall heat dissipation. Compared to casting, this allows for more flexible shape design and eliminates defects such as pores and cracks. Using pure aluminum as the raw material ensures high thermal conductivity, ensuring excellent heat dissipation.

[0093] Preferably, the method for preparing the main conductive cylinder further comprises:

[0094] Step 5: Process a heat dissipation channel 5 and install a support member 4 on the surface of the cylinder formed by the main structure 1, the conductive layer 2 and the external heat dissipation structure 3. The heat dissipation channel 5 is used to realize the dissipation of part of the heat from the inside of the main conductive cylinder by air convection, and form an air heat circulation channel to ensure the overall heat dissipation capacity. The support member 4 is used to support the main structure 1, the conductive layer 2 and the external heat dissipation structure 3.

[0095] According to the present invention, the main structure 1 is fabricated by coiling and welding, using a high-strength aluminum alloy to ensure mechanical strength. The conductive layer 2 is deposited directly on the outer surface of the main structure 1 using pure aluminum wire using additive manufacturing, forming an integrated structure and enabling the integrated processing of dissimilar metals. The pure aluminum ensures the structural conductivity, improving current flow capacity, and the high electrical conductivity reduces heat generation. An external heat dissipation structure 3 is then deposited on the outer surface of the conductive layer 2 using pure aluminum wire, effectively increasing the heat dissipation area of ​​the main conductive cylinder and improving heat dissipation capacity. The resulting main conductive cylinder exhibits high mechanical strength and balanced electrical and thermal conductivity. This combined coiling and additive manufacturing process improves current flow capacity and effectively increases heat dissipation while meeting mechanical strength requirements. This effectively reduces production costs, increases material utilization, and shortens processing cycles, demonstrating significant practical significance. Compared to traditional casting methods, this method eliminates the need for pre-molding, shortening processing cycles and production costs. Furthermore, by dividing functional areas, the integrated formation of different metal structures can be achieved, significantly reducing temperature rise in circuit breakers.

[0096] The present invention is further described below through specific examples. However, these examples are merely exemplary and do not constitute any limitation to the scope of protection of the present invention.

[0097] Example 1

[0098] (1) Establish a main conductive cylinder model with the following dimensions: the overall length of the main conductive cylinder model is 910 mm; the outer diameter of the main structure 1 model is 1060 mm, the wall thickness is 30 mm, and the length is 910 mm; the conductive layer 2 model is located outside the main structure 1, with a thickness of 12 mm and a length of 910 mm; the external heat dissipation structure 3 model is approximately annular, and its cross-section perpendicular to the extension direction of the main structure 1 is a triangle. The side length S of the bottom of a single external heat dissipation structure 3 in the external heat dissipation structure 3 model connecting with the main structure 1 model is 45 mm, the height H of the triangle vertex perpendicular to the main structure 1 model is 80 mm, the spacing L between the external heat dissipation structure 3 models is 45 mm, and the angle θ at the notch at the bottom of the external heat dissipation structure 3 is 80°, accounting for 22.2% of the complete circumference;

[0099] The thickness of the conductive layer 2 model is determined according to the following steps:

[0100]

[0101] Where δ is the skin depth of the skin effect, ω is the AC frequency, σ is the electrical conductivity of the conductor, and μ is the magnetic permeability of the conductor. The thickness of the conductive layer 2 is determined to be 12 mm.

[0102] (2) Based on the dimensions of the main structure 1 in the main conductive cylinder model in step (1), a 6061 aluminum alloy with a length of 3350 mm, a width of 910 mm, and a thickness of 30 mm was selected as the raw material. The plate was rolled using a plate rolling machine, and the longitudinal gap generated by the rolling was welded. The plate was rolled back into a circular shape, and the overall external dimensions, roundness, and perpendicularity of the axis relative to the end face of the rolled aluminum alloy cylinder were measured to ensure that the above dimensions met the dimensional requirements of the main structure 1 in step (1).

[0103] (3) The conductive layer 2 model is sliced ​​in layers in the slicing software to obtain a slice model of the conductive layer 2. The slice thickness of the conductive layer 2 slice model is set to 2 mm. The conductive layer 2 model and the conductive layer 2 slice model are imported into the path planning software. The central axis of the main structure 1 is used as the rotation axis, and the outer surface of the main structure 1 is used as the reference plane. The slice layers are parallel to the reference plane, the melting spacing is 3 mm, and the AC welding current parameters are set to 50 Hz, the peak current is 200 A, the base current is 100 A, and the duty cycle is 50%; the walking speed is 2 mm / s, the wire feeding speed is 2 m / min, the arc length is 5 mm, and the argon gas flow rate is 18 L / min.

[0104] The main structure 1 is preheated at 100° C., and additive manufacturing is performed using pure aluminum wire with a diameter of 1.2 mm according to the above parameters to deposit the conductive layer 2 .

[0105] (4) The external heat dissipation structure 3 model is sliced ​​in layers in the slicing software to obtain a slice model of the external heat dissipation structure 3. The slice thickness of the slice model of the external heat dissipation structure 3 is set to 2 mm. The external heat dissipation structure 3 model and the slice model of the external heat dissipation structure 3 are imported into the path planning software. The central axis of the main structure 1 is used as the rotation axis, and the outer surface of the conductive layer 2 is used as the reference plane. The slice layers are parallel to the reference plane, the melting spacing is 3 mm, and the AC welding current parameters are set to 50 Hz, the peak current is 200 A, the base current is 100 A, and the duty cycle is 50%; the walking speed is 2 mm / s, the wire feeding speed is 2 m / min, the arc length is 5 mm, and the argon flow rate is 18 L / min.

[0106] The main structure 1 including the conductive layer 2 is preheated at 100° C., and an external heat dissipation structure 3 is deposited by additive manufacturing using 1.2 mm pure aluminum wire according to the above parameters.

[0107] (5) Heat dissipation channels 5 with a size of 500 mm × 100 mm are machined on the left and right sides of the upper end of the main structure 1 containing the conductive layer 2 and the external heat dissipation structure 3, and four support members 4 are installed at the notch at the bottom of the external heat dissipation structure 3.

[0108] The present invention has been described in detail above with reference to preferred embodiments and exemplary examples. However, it should be noted that these specific embodiments are merely illustrative explanations of the present invention and do not constitute any limitation on the scope of protection of the present invention. Various improvements, equivalent substitutions, or modifications may be made to the technical content of the present invention and its embodiments without departing from the spirit and scope of protection of the present invention, and all of these fall within the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the appended claims.

Claims

1. A main conductive cylinder for an AC circuit breaker, characterized in that: The main conductive cylinder comprises a main structure (1), a conductive layer (2) and an external heat dissipation structure (3). The main structure (1) is obtained by coil welding, the conductive layer (2) is deposited on the outer surface of the main structure (1) by an additive manufacturing method, and the external heat dissipation structure (3) is deposited on the outer surface of the conductive layer (2) by an additive manufacturing method.

2. The main conductive cylinder according to claim 1, characterized in that: Preferably, the main structure (1) is used to support structural strength, and the conductive layer (2) is used to reduce current resistance to reduce heat generation.

3. The main conductive cylinder according to claim 1, characterized in that: The external heat dissipation structure (3) is used to increase the heat dissipation area and improve the heat dissipation capacity.

4. The main conductive cylinder according to claim 1, characterized in that: The main structure (1) has a length of 800-1000 mm and an outer diameter of 1000-1100 mm.

5. The main conductive cylinder according to claim 1, characterized in that: The wall thickness of the main structure (1) is 20 to 40 mm.

6. The main conductive cylinder according to claim 1, characterized in that: The external heat dissipation structures (3) are distributed at equal intervals along the outer surface of the conductive layer (2).

7. The main conductive cylinder according to claim 6, characterized in that: The spacing between the external heat dissipation structures (3) is 40 to 50 mm.

8. The main conductive cylinder according to claim 1, characterized in that: A heat dissipation channel (5) is provided on the surface of the cylinder formed by the main structure (1), the conductive layer (2) and the external heat dissipation structure (3). The heat dissipation channel (5) is used to dissipate part of the heat from the inside of the main conductive cylinder by air convection, thereby forming a heat circulation flow channel for the air.

9. The main conductive cylinder according to claim 8, characterized in that: The number of the heat dissipation channels (5) is 2 to 6.

10. A method for preparing the main conductive cylinder according to any one of claims 1 to 9, characterized in that: The method comprises: Step 1, establishing a main conductive cylinder model, wherein the model includes a main structure (1) model, a conductive layer (2) model and an external heat dissipation structure (3) model; Step 2, preparing the main structure (1) by coil welding according to the main structure (1) model; Step 3, depositing the conductive layer (2) on the outer surface of the main structure (1) by additive manufacturing according to the conductive layer (2) model; Step 4: According to the external heat dissipation structure (3) model, the external heat dissipation structure (3) is deposited on the outer surface of the conductive layer (2) by additive manufacturing to obtain the main conductive cylinder.

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