A manufacturing method of a circuit breaker arc striking structure

Abstract

The application belongs to the technical field of electric power, and specifically discloses a manufacturing method of an arc striking structure of a circuit breaker, which comprises the following steps: Step 1: a copper sheet is used to manufacture an upper arc striking piece conductive section, and an iron sheet is used to manufacture an upper arc striking piece arc striking section; Step 2: the upper arc striking piece conductive section and the upper arc striking piece arc striking section are welded, and the welding mode is brazing, medium-frequency welding or friction welding; Step 3: the welding position of the upper arc striking piece conductive section and the upper arc striking piece arc striking section is rolled to obtain an upper arc striking piece; Step 4: a copper-iron-phosphorus alloy is used to manufacture a movable contact plate, and then the movable contact plate is processed to form a contact point part on the movable contact plate; and Step 5: the upper arc striking piece and the movable contact plate are installed into a circuit breaker shell to form an arc striking structure of the circuit breaker.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of electric power, and particularly relates to a manufacturing method of an arc introduction structure of a circuit breaker. BACKGROUND

[0002] The circuit breaker is an important control and protection device in a low-voltage power distribution system, and can rapidly open a fault current when an overload or short-circuit fault occurs in the power distribution system, thereby protecting the power distribution system and electrical equipment. When a short circuit or overload occurs in the circuit, the tripping mechanism of the circuit breaker automatically cuts off the circuit, and a large amount of arc is generated in the process of cutting off the circuit. The arc generates high temperature and high pressure, and if the arc is not dispersed and extinguished in time, the circuit breaker can be easily broken down or burned, which seriously affects the breaking capacity of the circuit breaker. Therefore, the arc is introduced into an arc extinguishing chamber through an arc introduction structure.

[0003] The arc introduction structure of the small circuit breaker includes a housing, a moving contact, an arc extinguishing chamber, and upper and lower arc introduction sheets for introducing an opening arc to the arc extinguishing chamber. The arc introduction angle and the arc introduction sheets are used to introduce the arc during breaking to the arc extinguishing chamber for arc extinguishing. The upper arc introduction sheet includes a conductive section provided with a static contact and an arc introduction section extending backward into the arc extinguishing chamber. The moving contact can move backward to close with the static contact, and when breaking, the moving contact moves forward to be stopped by the upper end of the upper arc introduction sheet. The small circuit breaker further includes a guard plate, a wiring terminal, and a bimetallic sheet for overheat protection, and the guard plate is connected with the lower arc introduction sheet, the bimetallic sheet, and the wiring terminal.

[0004] In actual use, the moving contact moves backward to close with the static contact, and when breaking is needed, the moving contact moves forward until being stopped by the upper end of the lower arc introduction sheet. The arc generated by the moving contact during breaking can be introduced to the arc extinguishing chamber by the upper and lower arc introduction sheets. The current upper arc introduction sheet is generally made of copper, which is relatively soft and can be easily volatilized by heat to generate metal vapor, thereby increasing the arc breaking energy. There is also a method of using iron for the arc introduction section of the upper arc introduction sheet, and using copper for the conductive section. The conductive section and the arc introduction section are fixed by spot welding, but the contact resistance at the spot welding position is large, and the temperature rises. In addition, the current moving contact includes a moving contact plate and a silver point. The material of the moving contact plate is copper, and during processing, the silver point needs to be welded on the moving contact plate. SUMMARY

[0005] Therefore, the present application provides a manufacturing method of an arc introduction structure of a circuit breaker to solve the problems of high temperature rise and complex processing of the current circuit breaker. For this purpose, the present application provides the following technical scheme.

[0006] A manufacturing method of an arc introduction structure of a circuit breaker includes the following steps:

[0007] Step 1: using a copper sheet to make a conductive section of an upper arc introduction sheet, and using an iron sheet to make an arc introduction section of the upper arc introduction sheet;

[0008] Step two: welding the upper arc strip conductive section and the upper arc strip arc striking section, and the welding method is brazing, medium frequency welding or friction welding;

[0009] Step three: rolling the welding position of the upper arc strip conductive section and the upper arc strip arc striking section to obtain the upper arc strip;

[0010] Step four: using copper-iron-phosphorus alloy to make the movable contact plate, and then processing the movable contact plate to form the contact point part on the movable contact plate;

[0011] Step five: installing the upper arc strip and the movable contact plate into the circuit breaker shell to form the circuit breaker arc striking structure.

[0012] Optionally, the copper-iron-phosphorus alloy is CuFe0.1P alloy.

[0013] The CuFe0.1P alloy contains 0.1wt% of Fe, 0.03wt% of P, and the balance of Cu.

[0014] Optionally, the welding method is brazing, and a solder layer is arranged between the upper arc strip conductive section and the upper arc strip arc striking section.

[0015] Optionally, the solder layer is copper.

[0016] Optionally, the contact point part is a protruding block integrally formed on the movable contact plate.

[0017] Optionally, the upper arc strip arc striking section is provided with a stationary contact part matched with the contact point part.

[0018] Optionally, the stationary contact part is made of the same material as the movable contact plate, and the stationary contact part is welded on the upper arc strip arc striking section.

[0019] Optionally, the upper arc strip conductive section comprises a straight line part, the end of the straight line part is bent to form a bent part, and the end of the bent part is provided with a connecting part for connecting with the upper arc strip arc striking section.

[0020] Optionally, the upper arc strip arc striking section comprises a stationary contact part, one end of the stationary contact part is provided with a first bent part for connecting with the upper arc strip conductive section, and the other end of the stationary contact part is provided with a second bent part.

[0021] Optionally, the relative deformation amount in the rolling process is 50% to 60%.

[0022] Optionally, the step five further comprises installing a lower arc strip in the shell for cooperating with the upper arc strip and the movable contact plate.

[0023] The application further provides a circuit breaker arc striking structure obtained by the above manufacturing method.

[0024] The beneficial effects of the present application are:

[0025] The manufacturing method of the arc striking structure of the circuit breaker in the present application, the upper arc striking piece selects copper to make the conductive section and iron to make the arc striking section, which are welded together through brazing, medium frequency welding or friction welding, and then the upper arc striking piece is pressed through the rolling process, so that the upper arc striking piece has low temperature rise and good conductive performance. It should be noted that the movable contact plate and the contact are made of the same material, and the processing is simple. The small circuit breaker adopting the structure of the present application can solve the problems of high temperature rise and complex processing of the existing circuit breaker. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the specific embodiments or prior art of the present application, the drawings needed in the specific embodiments or prior art description will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0027] Figure 1 It is a schematic diagram of the upper arc striking piece;

[0028] Figure 2 It is a schematic diagram of the components of the upper arc striking piece;

[0029] Figure 3 It is a schematic diagram of the welding structure of the upper arc striking piece;

[0030] Figure 4 It is a schematic diagram of the movable contact plate;

[0031] Figure 5 It is a schematic diagram of the circuit breaker structure.

[0032] Markings in the figure: 1. upper arc striking piece, 11. upper arc striking piece conductive section, 12. upper arc striking piece arc striking section, 13. solder layer, 2. movable contact plate, 21. contact part, 111. straight line part, 112. bending part, 121. static contact part, 122. first bending part, 123. second bending part, 31. shell, 32. arc extinguishing chamber, 33. lower arc striking piece, 34. transmission mechanism. DETAILED DESCRIPTION

[0033] The technical solutions of the present application will be described below in conjunction with the drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0034] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0035] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0036] In addition, the technical features involved in the different embodiments of the application described below can be combined with each other as long as there is no conflict between them.

[0037] The present application provides a manufacturing method of an arc striking structure of a circuit breaker, comprising the following steps:

[0038] Step one: using copper sheet to make the upper arc striking piece conductive section 11, and using iron sheet to make the upper arc striking piece arc striking section 12.

[0039] Step two: welding the upper arc striking piece conductive section 11 and the upper arc striking piece arc striking section 12, and the welding method adopts brazing, medium frequency welding or friction welding.

[0040] Step three: rolling the welding part of the upper arc striking piece conductive section 11 and the upper arc striking piece arc striking section 12 to obtain the upper arc striking piece.

[0041] Step four: using copper-iron-phosphorus alloy to make the movable contact plate 2, and then processing the movable contact plate 2 to form the contact part 21 on the movable contact plate; as shown in the drawing, the contact part 21 is a protruding block integrally formed on the movable contact plate. Figure 4

[0042] Step five: installing the upper arc striking piece and the movable contact plate into the circuit breaker shell to form the arc striking structure of the circuit breaker. The step five further comprises installing a lower arc striking piece in the shell for cooperating with the upper arc striking piece and the movable contact plate.

[0043] Among them, as shown in the drawings, Figure 1 and Figure 2 ​As shown, the upper arc strip conductive section 11 includes a straight section 111, the straight section 111 is bent at one end to form a bending section 112, and the bending section 112 is provided with a connecting section for connecting with the upper arc strip arc striking section 12.

[0044] The upper arc strip arc striking section includes a static contact section 121, one end of the static contact section 121 is provided with a first bending section 122 for connecting with the upper arc strip conductive section, and the other end of the static contact section is provided with a second bending section 123. The second bending section 123 is mainly used for fixing the upper arc strip in the circuit breaker shell.

[0045] The copper-iron-phosphorus alloy is CuFe0.1P alloy. The CuFe0.1P alloy is a high-performance copper-based material, which combines the excellent electrical conductivity and thermal conductivity of copper with the strengthening effect of iron and phosphorus elements. Its chemical composition is based on copper (Cu), with the addition of trace amounts of iron (Fe, 0.05% to 0.15%) and phosphorus (P, 0.025% to 0.04%). The iron element improves the strength, and the phosphorus element stabilizes the alloy structure and enhances the oxidation resistance. The CuFe0.1P alloy used in the present application contains 0.1wt% Fe and 0.03wt% P, with the balance being Cu. The density of the CuFe0.1P alloy is 8.91 g / cm³, and the melting point is 1083°C. The electrical conductivity reaches 85% IACS (International Annealed Copper Standard), reaching the level of pure copper. The thermal conductivity is 350 W / m·K. This alloy balances electrical conductivity, strength, and environmental adaptability through optimized composition and process, making it an ideal material for high-precision electronic devices and harsh working conditions.

[0046] Unlike the prior art, which connects the upper arc strip conductive section 11 and the upper arc strip arc striking section 12 by resistance welding, the welding method in the present application is brazing, medium-frequency welding, or friction welding. Brazing is a process that connects workpieces by melting filler metal (brazing filler metal), and its core feature is that the base material does not melt, but only relies on the brazing filler metal to wet and flow and combine with the base material to form a joint. It is suitable for connecting different materials, so it is suitable for copper-iron connection in the present application. The joint is smooth and flat, with little deformation, making it suitable for precision devices. It is easy to mass-produce, efficient, and low in energy consumption. In the context of circuit breaker arc striking pieces and other scenarios, the use of matching copper-based brazing filler metal (such as CuP series) can achieve reliable connection of high-conductivity joints, significantly reducing the resistance at the welding point, avoiding the problem of high temperature rise, reduced structural strength, and reduced arc striking ability caused by high resistance at the welding point.

[0047] Friction welding is a solid-phase joining technique that utilizes the heat generated by the friction of the workpiece contact surfaces as a heat source to cause plastic deformation of the material under pressure and achieve welding. The core steps include: high temperature is generated by high-speed rotation or vibration friction. Under the combined action of pressure and heat, the interface material softens and flows. After cooling, high-strength metallurgical bonding is formed. Friction welding has the characteristics of high strength, high efficiency and environmental protection, and is also suitable for the copper-iron connection in the present application, which can form reliable connection and also can avoid the problem of high resistance at the welding point, high temperature rise, and reduced structural strength and arc striking ability in the prior art.

[0048] Medium frequency welding is a resistance welding process realized by using medium frequency inverter technology (frequency range 1-4 kHz), which realizes precise and efficient metal connection by converting power frequency alternating current (50 / 60 Hz) into high frequency direct current. It is suitable for difficult-to-weld materials such as copper alloy and plated steel sheet, and can form reliable connection and also can avoid the problem of high resistance at the welding point, high temperature rise, and reduced structural strength and arc striking ability in the prior art.

[0049] The bonding strength between the upper arc striking piece conductive section 11 and the upper arc striking piece arc striking section 12 can be further enhanced by rolling after welding, avoiding the problem of high resistance at the welding point. The relative deformation amount of the rolling process is 50%~60%. In this embodiment, 2.5mm thick conductive sheet (copper) and arc striking sheet (iron) are first selected and welded together by brazing, medium frequency welding, friction welding, etc., and then the upper arc striking piece is pressed to 1.5mm thick by rolling process.

[0050] The welding method in this embodiment specifically adopts brazing, and a solder layer 13 is arranged between the upper arc striking piece conductive section and the upper arc striking piece arc striking section. Specifically, the solder layer is copper. The end of the bending part 112 and the end of the first bending part 122 are welded together by solder to form the structure shown in Figure 3

[0051] Further, in some specific embodiments, a stationary contact part cooperating with the contact part is arranged on the upper arc striking piece arc striking section; the stationary contact part is made of the same material as the movable contact plate, and the stationary contact part is welded on the upper arc striking piece arc striking section.

[0052] After assembly, a small circuit breaker is obtained as shown in Figure 5 ​As shown: including the shell 31, the shell 31 is installed with the movable contact plate 2, the arc extinguishing chamber 32, the upper arc guiding piece 1, the lower arc guiding piece 33 and the transmission mechanism 34. The upper arc guiding piece 1 includes a conductive section and an arc guiding section for guiding the corresponding arc into the arc extinguishing chamber, the tail end of the arc guiding section extends to the gas outlet side of the arc extinguishing chamber 32. In actual use, under the drive of the transmission mechanism 34, the movable contact plate 2 moves backward and closes with the static contact part 121 of the upper arc guiding piece 1, when it is necessary to open, under the drive of the transmission mechanism 34, the movable contact plate 2 moves forward until it is stopped by the upper end of the lower arc guiding piece 33, the arc generated by the opening of the movable contact plate can be guided to the arc extinguishing chamber 32 by the upper and lower arc guiding pieces.

[0053] The manufacturing method of the circuit breaker arc guiding structure in the application, the upper arc guiding piece selects copper to make the conductive section and the iron arc guiding section, which are welded together by brazing, medium frequency welding or friction welding, and then the upper arc guiding piece is pressed through rolling process, so that the obtained upper arc guiding piece has low temperature rise and good conductivity. It should be noted that the movable contact plate and the contact are made of the same material, which is simple to process. The small circuit breaker with the structure of the application can solve the problems of high temperature rise and complex processing of the existing circuit breaker.

[0054] Obviously, the above embodiments are only examples for clearly illustrating, and not limited to the embodiments. For ordinary skilled in the art, other different forms of changes or variations can be made on the basis of the above description. Here, it is not necessary and impossible to enumerate all the embodiments. The obvious changes or variations derived therefrom are still within the protection scope of the application.

Claims

1. A method for manufacturing an arc-starting structure for a circuit breaker, characterized in that, Includes the following steps: Step 1: Use copper sheets to make the conductive section of the upper arc-leading plate, and use iron sheets to make the arc-leading section of the upper arc-leading plate; Step 2: Weld the conductive segment of the upper arc-leading plate and the arc-leading segment of the upper arc-leading plate; the welding method is brazing, and a solder layer is provided between the conductive segment of the upper arc-leading plate and the arc-leading segment of the upper arc-leading plate; The solder layer is copper; Step 3: Roll the welding parts of the conductive section and the arc-leading section of the upper arc-leading sheet to obtain the upper arc-leading sheet; Step 4: The moving contact plate is made of copper-iron-phosphorus alloy, and then the moving contact plate is processed to form the contact part; the copper-iron-phosphorus alloy is CuFe0.1P alloy; the CuFe0.1P alloy contains 0.1wt% Fe, 0.03wt% P, and the balance is Cu; Step 5: Install the upper arc-leading plate and the moving contact plate into the circuit breaker housing to form the circuit breaker arc-leading structure.

2. The method for manufacturing the arc-starting structure of a circuit breaker according to claim 1, characterized in that, The contact portion is a protrusion integrally formed on the moving contact plate.

3. The method for manufacturing the arc-starting structure of a circuit breaker according to claim 1, characterized in that, The upper arc-drawing plate has a stationary contact head that mates with the contact portion on its arc-drawing segment; And / or, the stationary contact head is made of the same material as the moving contact head plate, and the stationary contact head is welded to the arc-leading segment of the upper arc-leading plate.

4. The method for manufacturing the arc-starting structure of a circuit breaker according to claim 1, characterized in that, The upper arc-leading plate conductive segment includes a straight section, the end of which is bent to one side to form a bent section, and the end of the bent section is provided with a connecting part for connecting with the upper arc-leading plate arc-leading segment.

5. The method for manufacturing the arc-starting structure of a circuit breaker according to claim 1, characterized in that, The upper arc-leading segment includes a stationary contact head. One end of the stationary contact head is provided with a first bend for connecting with the conductive segment of the upper arc-leading segment, and the other end of the stationary contact head is provided with a second bend.

6. The method for manufacturing the arc-starting structure of a circuit breaker according to claim 1, characterized in that, The relative deformation during the rolling process is 50% to 60%.

7. The method for manufacturing the arc-starting structure of a circuit breaker according to claim 1, characterized in that, Step five also includes installing a lower arc-drawing plate inside the housing for cooperating with the upper arc-drawing plate and the moving contact plate.

8. The circuit breaker arc-starting structure obtained by the manufacturing method according to any one of claims 1 to 7.

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