Moving contact of miniature circuit breaker, preparation method and miniature circuit breaker

Abstract

The invention relates to the field of miniature circuit breakers, in particular to a moving contact of a miniature circuit breaker, a preparation method and the miniature circuit breaker. According to the moving contact with the two gears of thicknesses, the driving section with the small thickness can achieve forming of a hole groove structure with the small edge gap through stamping, the conductive section with the large thickness forms a conductive part between the moving contact and the electric connecting part, the large thickness can achieve the larger cross section area, and therefore temperature rise is reduced. According to the single-breakpoint large-current miniature circuit breaker provided by the invention, the large-current specification requirement of a 80A-125A miniature circuit breaker can be met under the width of 20mm-30mm, the problem that the uniformity of the pressure and synchronism of a contact adopting a double-breakpoint structure in the current market cannot be ensured is solved, the application risk of a product is reduced, the power consumption is reduced, and the long-term operation requirement of the product is met.

Description

Technical Field

[0001] The present invention relates to the field of miniature circuit breakers, and in particular to a moving contact of a miniature circuit breaker, a preparation method and the miniature circuit breaker. Background Art

[0002] Miniature circuit breakers, also known as miniature circuit breakers, are mainly used in various places such as industry, commerce, high-rise and residential buildings. They are used for AC and DC, with rated voltages below DC2000V and AC2000V. They are used as overload and short-circuit protection devices for distribution lines and equipment, and can also be used for infrequent on-off operation and conversion of lines. The width of existing miniature circuit breakers 1P is 1 modulus, that is, 18mm (63A and below specifications) or 27mm (80A~125A). However, at present, miniature circuit breakers are developing towards intelligence and miniaturization. The high-performance product design of 125A miniature circuit breakers with a modulus of 18mm-27mm will become the development trend in the circuit breaker industry, and it is also in line with the national policy of increasing revenue and reducing expenditure. Conventional structure miniature circuit breakers cannot meet the application requirements of 125A high current. Conventional products have too high temperature rise at an altitude of 2000m, which is easy to burn products and lines. The burning is more serious when the temperature is too high at an altitude of 3000m-5000m and in outdoor operation in summer.

[0003] At present, the difficulties in developing large-current small circuit breakers mainly lie in the following: the thickness of the moving contact of the current small circuit breaker is relatively thin, usually about 1.5mm, and its use in large current will cause excessive temperature rise; if the thickness of the moving contact is increased to meet the requirements of 80A-125A large current use, the thickness of the moving contact needs to be increased to more than 3mm, but the current process is difficult to achieve the preparation of moving contacts of this thickness. The current stamping equipment cannot stamp parts with smaller edge gaps on thicker copper materials. In addition, thicker moving contacts will cause the overall thickness of the circuit breaker operating mechanism to increase, and the modular specifications of the small circuit breaker cannot meet the installation of thicker operating mechanisms.

[0004] Based on the above reasons, the current mainstream technical approach to reducing the internal temperature rise of large current small circuit breakers is to adopt a double-breakpoint contact structure. However, due to the increase in the number of parts and assembly procedures, the cost is significantly higher than that of small circuit breakers with a single-breakpoint contact structure. In addition, the double-breakpoint structure cannot ensure uniform contact pressure and synchronization after closing, and product burning problems often occur in market applications. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art and to provide a moving contact of a miniature circuit breaker, a preparation method and a miniature circuit breaker.

[0006] The technical solution adopted by the present invention is as follows: a moving contact of a small circuit breaker, which includes a driving section and a conductive section, the driving section is provided with a connection hole along its thickness direction, the conductive section has an electrical connection portion for forming a connection with a conductive wire and a moving contact for cooperating with a static contact; the thickness of the conductive section is D1, the thickness of the driving section is D2, and D1 is greater than D2.

[0007] Preferably, D1 is 3-5 mm, and D2 is 1.0-2.0 mm.

[0008] One or both side surfaces of the conductive segment are raised relative to the side surface of the driving segment, and a bevel transition is formed between the two.

[0009] The method for preparing the moving contact of the miniature circuit breaker as described above comprises the following steps:

[0010] Step (1), designing a copper material drawing die, wherein the die cavity of the copper material drawing die includes a first die cavity with a width of D1 and a second die cavity with a width of D2;

[0011] Step (2), the contact material is drawn through the cavity of a copper material drawing die to form a long copper material having two thicknesses of D1 and D2;

[0012] Step (3), stamping the long strip of copper material to obtain a moving contact.

[0013] A single-breakpoint high-current miniature circuit breaker comprises a shell, wherein an operating mechanism, the miniature circuit breaker as described above, a static contact, a first wiring terminal, and a second wiring terminal are arranged in the shell, wherein the operating mechanism comprises a lock catch, a trip catch, and a moving contact frame, wherein the moving contact and the moving contact frame are hingedly connected via a first connecting shaft passing through a connecting hole, wherein the electrical connection portion is electrically connected to the first wiring terminal via a conductive wire, wherein the static contact is electrically connected to the second wiring terminal, and wherein the moving contact is driven by the operating mechanism to rotate so that the moving contact and the static contact are disconnected / connected.

[0014] Preferably, the lock catch and the moving contact frame are hingedly connected to the shell through a second connecting shaft, and the driving section is provided with an arc hole along its thickness direction, and the arc hole is for the second connecting shaft to pass through; the jump catch and the moving contact frame are hingedly connected through a third hinge shaft; the operating mechanism includes a handle and a connecting rod, and the handle, the connecting rod and the jump catch are connected in sequence.

[0015] Preferably, an arc extinguishing assembly is provided in the shell, the arc extinguishing assembly includes an arc extinguishing chamber, a slit assembly is provided on one side of the arc extinguishing chamber entrance, a magnetizing assembly is provided outside the slit assembly, the slit assembly is composed of two oppositely arranged gas production plates, and a slit is formed between the two gas production plates for the static contact and the moving contact to extend into.

[0016] Preferably, a gas return slope is provided on one side of the gas production plate close to the arc extinguishing chamber inlet.

[0017] Preferably, the arc extinguishing assembly comprises an arc striking piece, wherein the arc striking piece has a first arc striking portion extending to the opening of the arc extinguishing chamber or a side thereof, and a second arc striking portion corresponding to the moving contact at the disconnecting position.

[0018] An arc blocking plate is arranged on the inner wall of the shell corresponding to the outer side of the static contact.

[0019] The beneficial effects of the present invention are as follows: The present invention provides a moving contact with two thicknesses, wherein the driving segment with a smaller thickness can be formed into a hole slot structure with a smaller edge gap by stamping, and the conductive segment with a larger thickness constitutes the conductive portion between the moving contact and the electrical connection portion. The larger thickness can achieve a larger cross-sectional area, thereby reducing the temperature rise. The present invention proposes a single-breakpoint high-current miniature circuit breaker for the first time, which can meet the requirements of 80A-125A high-current breaking. There is no problem that the contact pressure and synchronization of the mainstream double-breakpoint structure in the current market cannot be guaranteed to be unified, which reduces the product application risk and reduces power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, without paying creative labor, other drawings obtained based on these drawings still belong to the scope of the present invention.

[0021] Figure 1 Schematic diagram of the structure of the moving contact of Example 1 of the present invention, (a) is a three-dimensional view, (b) is a side view;

[0022] Figure 2 This is a schematic structural diagram of a copper material drawing die for a moving contact in accordance with Embodiment 1 of the present invention;

[0023] Figure 3 This is a schematic diagram of the process of preparing the moving contact of Example 1 of the present invention;

[0024] Figure 4 Schematic diagram of the structure of the moving contact of Example 2 of the present invention, (a) is a three-dimensional view, (b) is a side view;

[0025] Figure 5 This is a schematic structural diagram of a miniature circuit breaker according to Embodiment 3 of the present invention;

[0026] Figure 6 This is a schematic diagram of the internal structure of a miniature circuit breaker according to Embodiment 3 of the present invention;

[0027] Figure 7 This is a schematic diagram of the structure of the operating mechanism of the miniature circuit breaker according to Embodiment 3 of the present invention;

[0028] Figure 8 This is a structural schematic diagram of an arc extinguishing mechanism of a miniature circuit breaker according to Embodiment 3 of the present invention;

[0029] Fig. 9 It is an exploded schematic diagram of the arc extinguishing mechanism of the miniature circuit breaker according to the third embodiment of the present invention;

[0030] Fig.10 A cross-sectional view of an arc extinguishing mechanism of a miniature circuit breaker according to Embodiment 3 of the present invention;

[0031] Fig.11 This is a schematic structural diagram of a gas production plate of a miniature circuit breaker according to Embodiment 3 of the present invention;

[0032] Fig.12 A schematic structural diagram of a miniature circuit breaker according to Embodiment 3 of the present invention from another angle;

[0033] Fig.13 for Fig.12 The enlarged schematic diagram of part A in the middle;

[0034] Fig.14 This is a schematic structural diagram of a miniature circuit breaker according to Embodiment 4 of the present invention;

[0035] Fig.15 An exploded view of a short-circuit heat dissipation assembly of a miniature circuit breaker according to Embodiment 4 of the present invention;

[0036] In the figure,

[0037] Moving contact 100, driving section 110, connecting hole 111, arc hole 112, spring hook hole 113, conductive section 120, electrical connection part 121, moving contact point 122;

[0038] Stationary contact-200;

[0039] Copper material drawing die-300, first die cavity-310, second die cavity-320;

[0040] Shell-400, arc baffle-410;

[0041] Operating mechanism 500, lock catch 510, trip catch 520, moving contact frame 530, first connecting shaft 540, second connecting shaft 550, third hinge shaft 560, handle 570, connecting rod 580;

[0042] Electromagnetic release - 610, temperature-sensitive double gold sheet - 620;

[0043] First connecting terminal-710, second connecting terminal-720;

[0044] Arc extinguishing assembly 800, arc extinguishing chamber 810, slit assembly 820, gas production plate 821, gas return slope 822, magnetizing assembly 830, magnetizing plate 831, connecting strip 832, arc striking piece 840, first arc striking part 841, second arc striking part 842;

[0045] Short-circuit heat dissipation assembly-900, short-circuit bar-910, connecting main board-911, connecting foot-912, radiator-920, bottom plate-921, heat dissipation fin-922, heat dissipation cover-930, back plate-931, upper end plate-932, side plate-933. DETAILED DESCRIPTION

[0046] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings.

[0047] It should be noted that all expressions using "first" and "second" in the embodiments of the present invention are for distinguishing two non-identical entities with the same name or non-identical parameters. It can be seen that "first" and "second" are only for the convenience of expression and should not be understood as limitations on the embodiments of the present invention. The subsequent embodiments will not explain this one by one.

[0048] The directions and positions mentioned in the present invention, such as up, down, front, back, left, right, inside, outside, top, bottom, side, etc., are only directions or positions with reference to the drawings. Therefore, the directions and positions used are used to explain and understand the present invention, but are not intended to limit the scope of protection of the present invention.

[0049] Embodiment 1:

[0050] A moving contact 100 of a miniature circuit breaker, such as Figure 1 As shown, it includes a driving segment 110 and a conductive segment 120 .

[0051] The driving section 110 is used to cooperate with the operating mechanism 500, and has a connection hole 111, an arc hole 112, and a spring hook hole 113 opened along the thickness direction thereof. The thickness of the driving section 110 is D2. Since the internal space of the small circuit breaker is extremely limited, the sizes of the connection hole 111, the arc hole 112, and the spring hook hole 113 are very small, and the edge gap is small, and D2 needs to be set smaller, so that the connection hole 111, the arc hole 112, and the spring hook hole 113 can be formed by stamping. It is preferred to set D2 to 1.0-2.0 mm. Too thin will affect the strength and cause the risk of easy breakage during the opening and closing process. Too thick will increase the difficulty of processing and affect the overall thickness of the operating mechanism. If the overall thickness of the operating mechanism is too thick, it will not be installed in the small circuit breaker.

[0052] The conductive segment 120 has an electrical connection portion 121 for forming a connection with the conductive wire and a movable contact 122 for cooperating with the static contact 200, that is, the conductive segment 120 constitutes a conductive portion for directly connecting the conductive wire and the movable contact 122. The thickness D1 of the conductive segment 120 affects the cross-sectional area of ​​the conductor, thereby affecting the temperature rise. In this embodiment, D1 is set to be larger than D2, and the temperature rise of the movable contact 100 during conduction is not affected by the thickness of the driving segment 110, so that it is not limited by the shortcomings of the stamping process, and the movable contact 100 of the miniature circuit breaker that meets the temperature rise requirements of large current is obtained. Preferably, D1 is set to be greater than 3mm. At the same time, in order to achieve rapid arc extinguishing and better reduce temperature rise, it is necessary to set gas-generating slit components on both sides of the movable contact 100 in the miniature circuit breaker. Therefore, it is preferably set to be less than 5mm to provide enough space in the miniature circuit breaker to install the slit components.

[0053] In this embodiment, one side wall of the conductive segment 120 is raised relative to the same side wall of the driving segment 110, and the two side walls are transitioned by an inclined plane, and the other side wall between the two is located in the same plane as the same side wall of the driving segment 110. The inclined plane transition can increase the strength of the portion where the driving segment 110 and the conductive segment 120 are connected.

[0054] The preparation method of the moving contact of this embodiment is also different from the prior art. The preparation method of this embodiment includes the following steps:

[0055] Step a, designing a copper material drawing die 300, such as Figure 2 As shown, the mold cavity of the copper material drawing mold 300 includes a first mold cavity 310 with a width of D1 and a second mold cavity 320 with a width of D2;

[0056] Step b, such as Figure 3 As shown, the contact material is drawn through the cavity of the copper material drawing die 300 to form a long copper material with two thicknesses of D1 and D2;

[0057] Step c: stamping the long strip of copper material to obtain a moving contact.

[0058] By using the moving contact provided in this embodiment, a small circuit breaker with a single breaking point and high current can be obtained.

[0059] Embodiment 2:

[0060] This embodiment provides a moving contact 100 of a miniature circuit breaker. The preparation method of this embodiment is exactly the same as that of the embodiment 1, and the structure is slightly different from that of the moving contact 100 of the embodiment 1. Figure 4 As shown, both side walls of the conductive segment 120 of the movable contact 100 of this embodiment are raised relative to the same side wall of the driving segment 110, and the two side walls are transitioned by an inclined surface.

[0061] Embodiment 3:

[0062] This embodiment provides a miniature circuit breaker, including a housing 400, such as Figure 6 As shown, the moving contact 100, the stationary contact 200, the operating mechanism 500, the tripping drive mechanism, the first wiring terminal 710, the second wiring terminal 720, and the arc extinguishing assembly 800 of Example 1 or Example 2 are installed inside.

[0063] The electrical connection portion 121 of the moving contact 100 is electrically connected to the first terminal 710 through a conductive wire, and the stationary contact 200 is electrically connected to the second terminal 720. When the moving contact 100 is engaged with the stationary contact 200, the first terminal 710 is electrically connected to the second terminal 720. When the moving contact 100 is separated from the stationary contact 200, the first terminal 710 is electrically connected to the second terminal 720.

[0064] like Figure 7 As shown, the operating mechanism 500 includes a handle 570, a connecting rod 580, a lock 510, a tripping buckle 520, and a moving contact frame 530. The handle 570, the connecting rod 580, and the tripping buckle 520 are hinged to the moving contact frame 530 through a third hinge shaft 560. The moving contact 100 is hingedly connected to the moving contact frame 530 through a first connecting shaft 540 passing through a connecting hole 111. The lock 510 and the moving contact frame 530 are hingedly connected to the housing 400 through a second connecting shaft 550. The driving section 110 is provided with an arc hole 112 along its thickness direction, and the arc hole 112 is for the second connecting shaft 550 to pass through, and a spring hook is provided between the shell 400 and the spring hook hole 113 of the moving contact 100. The lock buckle 510 and the trip buckle 520 have a re-locking state and a tripping state. In the re-locking state, the opening and closing states of the moving contact 100 can be achieved through the handle 570. When the lock buckle 510 is rotated to the tripping state, the spring pulls the moving contact 100 to automatically open the moving contact 100.

[0065] The tripping drive mechanism is used to drive the lock 510 to rotate from the re-locking state to the tripping state, and specifically includes an electromagnetic tripper 610 electrically connected between the static contact 200 and the second terminal 720 and a temperature-sensitive double gold sheet 620 between the moving contact 100 and the first terminal 710 to achieve short circuit, overcurrent and overheating protection. The specific induction drive principle is basically consistent with the existing one and will not be elaborated in detail.

[0066] like Figure 8 , Fig. 9As shown, the arc extinguishing assembly 800 includes an arc extinguishing chamber 810, a slot assembly 820 is provided at one side of the entrance of the arc extinguishing chamber 810, a magnetizing assembly 830 is provided outside the slot assembly 820, and the slot assembly 820 is composed of two gas production plates 821 arranged opposite to each other, and a slot is formed between the two gas production plates 821 for the static contact 200 and the moving contact 100 to extend into. The arc extinguishing chamber 810 includes a plurality of arc extinguishing grids to achieve rapid arc extinguishing, and the housing 400 is provided with an exhaust port corresponding to the outlet of the arc extinguishing chamber 810. The slot assembly 820 is arranged on both sides of the moving contact 100 and the static contact 200. During the opening process, the arc formed between the moving contact 100 and the static contact 200 acts on the gas production plate 821, forming a gas blowing effect, so that the arc is quickly blown to the arc extinguishing chamber 810 to avoid the increase of temperature rise. The magnetizing component 830 is arranged outside the slit component 820, which effectively forms a magnetic blowing effect, improves the arc striking efficiency, and thus makes the arc extinguishing effect better.

[0067] Specifically, Fig. 9 As shown, the magnetizing component 830 has two magnetizing parts, which include a magnetizing plate 831 located on the outside of the gas producing plate 821 and a connecting strip 832 located on one side of the magnetizing plate 831 and extending from one side of the gas producing plate 821. The connecting strips 832 of the two magnetizing parts are fixedly connected, and the two gas producing plates 821 are respectively fixed on the two magnetizing plates 831.

[0068] Further, such as Fig.10 , Fig.11 As shown, the gas production plate 821 is provided with a return air slope 822 on one side close to the entrance of the arc extinguishing chamber 810. When the airflow with the arc blows toward the arc extinguishing chamber 810 and collides with the arc extinguishing grid, there will be a certain back-blowing effect. The back-blowing airflow will return again when it hits the return air slope 822, reducing the possibility of returning to the slit.

[0069] The arc extinguishing assembly 800 includes an arc striking piece 840, wherein the arc striking piece 840 has a first arc striking portion 841 extending to the opening of the arc extinguishing chamber 810 or to the side thereof, and a second arc striking portion 842 corresponding to the moving contact 100 at the disconnecting position. Fig.10 As shown, during the opening rotation of the moving contact 100 , the second arc-starting portion 842 can form a good arc-starting effect on the moving contact 100 . Furthermore, the connecting strip 832 of the magnetizing component 830 is located outside the arc-starting piece 840 .

[0070] The double gold sheet 620 is directly connected to the arc striking sheet 840 to prevent the temperature in the arc extinguishing chamber 810 from being too high.

[0071] like Fig.12 , Fig.13As shown, an arc baffle 410 is provided on the inner wall of the housing 400 corresponding to the outer side of the static contact 200. This prevents the arc from escaping to the operating mechanism 500 and affecting the flexible movement of the operating mechanism 500. The connection part of the static contact 200 and the conducting part matched with the moving contact 100 are bent and connected, and the arc baffle 410 is L-shaped and is provided corresponding to the bending part between the connection part and the conducting part of the static contact 200.

[0072] At present, the mainstream high-current miniature circuit breakers on the market are all double-breakpoint structures. The present invention compares the 125A high-current miniature circuit breaker of this embodiment with a 125A high-current miniature circuit breaker of a foreign brand with double-breakpoint structure whose performance is more recognized by the market. The comparison results are shown in Table 1. Compared with similar international 80A-125A products, the temperature rise of the product of the present invention is reduced by more than 30%, reducing the product application risk and reducing power consumption.

[0073] The arc extinguishing assembly of this embodiment was tested for its load life. As shown in Table 2, the test results are very significant, and are significantly better than the data of the current conventional large-current miniature circuit breakers.

[0074] Table 1 Test data of 125A frame miniature circuit breaker

[0075]

[0076] Table 2: Load life test 2P in this embodiment as an example DC500V-125A

[0077]

[0078]

[0079] Embodiment 4:

[0080] like Fig.14 As shown, this embodiment provides a short-circuit heat dissipation assembly 900 based on the miniature circuit breaker of Embodiment 3. The short-circuit heat dissipation assembly 900 is detachably mounted on the miniature circuit breaker body.

[0081] It includes a short-circuit bar 910, a radiator 920 and a heat dissipation cover 930. The short-circuit bar 910 includes a connecting mainboard 911 and a connecting pin 912. The radiator 920 includes a bottom plate 921 and heat dissipation fins 922. The bottom plate 921 fits the connecting mainboard 911 and is fixedly connected to the connecting mainboard 911. The heat dissipation cover 930 includes a back plate 931, an upper end plate 932 and side plates 933. The back plate 931 is located on the outside of the heat dissipation fins 922 and is provided with heat dissipation holes. The side plates 933 are located on both sides of the radiator 920, so that the heat dissipation cover 930 is arranged outside the radiator 920 to form a protective effect on the radiator 920. The heat dissipation cover 930 is detachably connected to the housing 400 of the miniature circuit breaker body. When the short-circuit bar 910 is plugged into the wiring terminals of the miniature circuit breaker body and the heat dissipation cover 930 is connected to the housing 400 of the miniature circuit breaker body, the short-circuit bar 910 and the radiator 920 are limited at the same time, so that the short-circuit bar 910, the radiator 920 and the wiring terminals of the miniature circuit breaker body remain connected.

[0082] Among them, a group of connecting pins 912 are bent and connected to the same side of the short-circuit bar 910, and the bending angle between them and the main board is 80-100 degrees, and a plurality of heat dissipation fins 922 are arranged on the bottom plate 921 at intervals and the angle between them and the bottom plate 921 is 80-100 degrees. The connecting pins 912 can be electrically connected to the second terminal 720 of the two-pole circuit breaker to realize the short-circuit series connection of the two-pole circuit breaker.

[0083] Specifically, the short-circuit bar 910 and the heat sink 920 can be in an integrated or split form, which is more convenient to produce than an integrated structure. The specific selection can be made according to the actual situation. Specifically in the present embodiment, the connecting main board 911 and the bottom plate 921 are in a split form; a plurality of heat dissipating fins 922 are evenly spaced on the radiator bottom plate 921; the angles between the connecting pins 912 and the connecting main board 911, the heat dissipating fins 922 and the bottom plate 921 are not specifically restricted and can be specifically set according to the actual situation. Specifically in the present embodiment, the optimal solution is set to be perpendicular to each other, with high space utilization. Based on the structure of the small circuit breaker body, the rectangular space on the side of the small circuit breaker body is fully utilized, and more heat dissipating fins can be arranged to improve the heat dissipation efficiency.

[0084] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A moving contact of a miniature circuit breaker, characterized in that: It comprises a driving section (110) and a conductive section (120); the driving section (110) is provided with a connection hole (111) along its thickness direction; the conductive section (120) has an electrical connection portion (121) for forming a connection with a conductive line and a movable contact (122) for cooperating with a stationary contact (200); the conductive section (120) has a thickness of D1, and the driving section (110) has a thickness of D2, wherein D1 is greater than D2.

2. The movable contact of the miniature circuit breaker according to claim 1, characterized in that: D1 is 3-5mm, D2 is 1.0-2.0mm.

3. The moving contact of the miniature circuit breaker according to claim 1, characterized in that: One or both side surfaces of the conductive segment (120) are raised relative to the side surface of the driving segment (110), and a bevel transition is formed between the two.

4. The method for preparing the moving contact of the miniature circuit breaker according to any one of claims 1 to 3, comprising the following steps: Step (a), designing a copper material drawing die (300), wherein a die cavity of the copper material drawing die (300) comprises a first die cavity (310) with a width of D1 and a second die cavity (320) with a width of D2; Step (b), the contact material is drawn through the mold cavity of a copper material drawing mold (300) to form a long copper material with two thicknesses of D1 and D2; Step (c), stamping the long strip of copper material to obtain a moving contact.

5. A single-breakpoint high-current miniature circuit breaker, comprising a housing (400), wherein an operating mechanism (500), a moving contact (100) of the miniature circuit breaker according to any one of claims 1 to 3, a stationary contact (200), a first wiring terminal (710), and a second wiring terminal (720) are arranged in the housing (400), wherein the operating mechanism (500) comprises a lock catch (510), a trip catch (520), and a moving contact frame (530), wherein the moving contact ( The movable contact (100) is hingedly connected to the movable contact frame (530) via a first connecting shaft (540) passing through the connecting hole (111); the electrical connecting portion (121) is electrically connected to the first connecting terminal (710) via a conductive wire; the stationary contact (200) is electrically connected to the second connecting terminal (720); the movable contact (100) is rotated under the drive of the operating mechanism (500) to disconnect / engage the movable contact (122) and the stationary contact (200).

6. The single-breakpoint high-current miniature circuit breaker according to claim 5, characterized in that: The lock buckle (510) and the moving contact frame (530) are hingedly connected to the housing (400) via a second connecting shaft (550); the driving section (110) is provided with an arc-shaped hole (112) along its thickness direction, and the arc-shaped hole (112) is for the second connecting shaft (550) to pass through; the jump buckle (520) and the moving contact frame (530) are hingedly connected via a third hinge shaft (560); the operating mechanism (500) comprises a handle (570) and a connecting rod (580); the handle (570), the connecting rod (580) and the jump buckle (520) are connected in sequence.

7. The single-breakpoint high-current miniature circuit breaker according to claim 5, characterized in that: An arc extinguishing assembly (800) is arranged in the housing (400), and the arc extinguishing assembly (800) includes an arc extinguishing chamber (810), a slit assembly (820) is arranged on one side of the entrance of the arc extinguishing chamber (810), and a magnetizing assembly (830) is arranged outside the slit assembly (820), and the slit assembly (820) is composed of two gas production plates (821) arranged opposite to each other, and a slit is formed between the two gas production plates (821) for the static contact (200) and the moving contact (100) to extend into.

8. The single-breakpoint high-current miniature circuit breaker according to claim 7, characterized in that: A gas return slope (822) is provided on one side of the gas production plate (821) close to the entrance of the arc extinguishing chamber (810).

9. The single-breakpoint high-current miniature circuit breaker according to claim 7, characterized in that: The arc extinguishing assembly (800) comprises an arc striking piece (840), wherein the arc striking piece (840) has a first arc striking portion (841) extending to the opening of the arc extinguishing chamber (810) or to a side thereof, and a second arc striking portion (842) corresponding to the moving contact (100) at a disconnecting position.

10. The single-breakpoint high-current miniature circuit breaker according to claim 5, characterized in that: An arc blocking plate (410) is provided on the inner wall of the housing (400) corresponding to the outer side of the static contact (200).

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