Moving contact connecting assembly and circuit breaker

Abstract

The invention relates to the technical field of low-voltage electric appliances, in particular to a moving contact connecting assembly and a circuit breaker. The moving contact connecting assembly comprises a copper foil structure, the copper foil structure comprises a first connecting part, a second connecting part and an arc-shaped transition part connected between the first connecting part and the second connecting part, one end, far away from the arc-shaped transition part, of the first connecting part is connected to a first end of a moving contact, and the other end of the first connecting part is connected to a second end of the moving contact. One end, far away from the arc-shaped transition part, of the second connecting part is connected to the external busbar, and the rotating center line of the moving contact is located between the first end and the second end; and the first connecting part is connected to the moving contact through rivet welding and / or the second connecting part is connected to the external busbar through rivet welding. By the adoption of the technical scheme, the copper foil structure does not have an area with excessive bending and relatively concentrated stress on the whole, so that the risk of damage and even breakage caused by back-and-forth bending of the copper foil structure is reduced, and the service life of the copper foil structure is prolonged.

Description

Technical Field

[0001] This invention relates to the field of low-voltage electrical technology, and in particular to a moving contact connection assembly and a circuit breaker. Background Technology

[0002] In conventional molded case circuit breakers, the moving contact is connected to the external busbar via a conductor. To reduce power consumption, some molded case circuit breakers use copper foil instead of conductors. When using copper foil to connect the moving contact and the external busbar, refer to... Figure 1 In the prior art, due to space constraints, it is generally necessary to use diffusion brazing to form a hard junction at both ends of the copper foil stack to make the copper foil stack a whole, and then weld the hard junctions at both ends of the copper foil stack to the moving contact and the external busbar respectively.

[0003] The existing connection methods for copper foil, moving contacts, and external busbars have at least the following problems: Figure 1 As shown, the copper foil stacks are roughly connected in a Z-shape between the moving contact and the external busbar. During the rotation of the moving contact, the connection area between the hardened junction and the middle of the copper foil, as well as the middle position of the copper foil, will be excessively bent, causing the copper foil to be easily damaged or even broken, affecting the performance of the circuit breaker. Summary of the Invention

[0004] The first objective of this invention is to provide a moving contact connection assembly to solve the technical problem in the prior art where copper foil is easily damaged or even broken, affecting the performance of the circuit breaker.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A moving contact connection assembly includes a copper foil structure, which is composed of one or more copper foil sheets stacked together. The copper foil structure includes a first connecting portion, a second connecting portion, and an arcuate transition portion connecting the first connecting portion and the second connecting portion. The end of the first connecting portion away from the arcuate transition portion is connected to a first end of the moving contact, and the end of the second connecting portion away from the arcuate transition portion is connected to an external busbar. The second end of the moving contact has a moving contact point, and the rotation center line of the moving contact is located between the first end and the second end of the moving contact. At least one of the first connecting portion and the second connecting portion is a U-shaped structure formed by bending the copper foil sheet or the copper foil stack, so that the first connecting portion is assembled and positioned with the moving contact and / or the second connecting portion is assembled and positioned with the external busbar by fasteners, and then connected by welding.

[0006] In some embodiments, the moving contact has an open position and a closed position rotated by a preset angle relative to the open position, and the included angle between the faces of the first connecting portion and the second connecting portion that are respectively close to the centroid of the arcuate transition portion is α; When the moving contact is in the closed position, 70°≤a≤85°; When the moving contact is in the open position, 10°≤a≤20°.

[0007] In some embodiments, the preset angle of rotation of the moving contact is 58°; When the moving contact is in the closed position, a = 76°; When the moving contact is in the open position, a = 16°.

[0008] In some embodiments, the two ends of the copper foil along its length are bent and joined together to form a hardened region, the hardened region being located at the first connection portion or the second connection portion; and / or, The first connecting portion includes a first arc segment and first connecting sections extending from both ends of the first arc segment. The moving contact connecting assembly further includes a first fastener connected to the moving contact. The first arc segment is pressed between the first fastener and the moving contact; and / or, The second connecting portion includes a second arc segment and second connecting segments extending from both ends of the second arc segment. The moving contact connecting assembly also includes a second fastener connected to the external busbar. The second arc segment is pressed between the second fastener and the external busbar.

[0009] In some embodiments, the first connecting portion includes a first connecting segment I and a first connecting segment II, the second connecting portion includes a second connecting segment I and a second connecting segment II, the arcuate transition portion includes a first arc segment and a second arc segment, the second arc segment surrounds the side of the first arc segment away from its centroid, the first connecting segment I, the first arc segment and the second connecting segment I are connected in sequence, and the first connecting segment II, the second arc segment and the second connecting segment II are connected in sequence; The included angle between the first connecting segment I and the second connecting segment I is a, and the included angle between the first connecting segment II and the second connecting segment II is b, where b > a.

[0010] In some embodiments, the moving contact is provided with a first positioning groove for the first connecting portion to be inserted; and / or, The external busbar is provided with a second positioning groove for the second connecting part to be inserted.

[0011] In some embodiments, the first fastener and / or the second fastener are rivets; and / or, The first fastener, the first connecting portion, and the moving contact are welded together as a single unit by riveting or welding; and / or, The second fastener, the second connecting part, and the external busbar are welded together as a whole by riveting.

[0012] In some embodiments, the two ends of the copper foil sheet or the copper foil stack along its length are bent and joined together to form a hardened region, and the end of the copper foil structure away from the hardened region is naturally bent to form the U-shaped structure. The hardened region is fixed to the external busbar by welding, and the U-shaped structure is fixed to the moving contact by riveting. The two ends of the copper foil sheet or the stack of copper foil sheets along its length are bent and then welded to form a hardened region, and the two ends of the copper foil structure respectively form the U-shaped structure. The hardened region is offset from the welding positions of the copper foil structure with the moving contact and the external busbar, respectively; or, The copper foil structure is composed of stacked copper foil sheets. One end of each stacked copper foil sheet is welded to form a hardened region, and the other end is bent to form a U-shaped structure. The hardened region is welded to the external busbar, and the U-shaped structure is riveted to the moving contact; or... The two ends of the copper foil sheet or the copper foil stack are respectively bent to form the U-shaped structure, and are respectively fixed to the moving contact and the external busbar by riveting.

[0013] In some embodiments, the middle portion of the arcuate transition portion protrudes toward or away from the second end of the moving contact; The copper foil sheet is a long, rectangular sheet.

[0014] A second object of the present invention is to provide a circuit breaker comprising the moving contact connection assembly described in any of the preceding claims.

[0015] The beneficial effects of this invention are: This invention provides a moving contact connection assembly and a circuit breaker having the moving contact connection assembly. The moving contact connection assembly includes a copper foil structure, which is composed of one or more copper foil sheets stacked together. The copper foil structure includes a first connecting portion, a second connecting portion, and an arc-shaped transition portion connecting the first connecting portion and the second connecting portion. The end of the first connecting portion away from the arc-shaped transition portion is connected to the first end of the moving contact, and the end of the second connecting portion away from the arc-shaped transition portion is connected to an external busbar. The second end of the moving contact has a moving contact point, and the rotation center line of the moving contact is located between the first end and the second end of the moving contact. At least one of the first connecting portion and the second connecting portion is a U-shaped structure formed by bending the copper foil sheet or the stack of copper foil sheets, so that the first connecting portion is assembled and positioned with the moving contact and / or the second connecting portion is assembled and positioned with the external busbar by fasteners, and then connected together by welding.

[0016] By adopting the above technical solution, the copper foil structure as a whole does not have areas of excessive bending or high stress concentration, thereby reducing the risk of damage or even breakage caused by repeated bending of the copper foil structure and improving the service life of the copper foil structure. In addition, at least one end of the copper foil structure 1 is a U-shaped structure, which can be used to form a riveting point, thereby allowing the U-shaped end of the copper foil structure 1 to be riveted and fixed, reducing or avoiding secondary welding of hardened areas on the copper foil structure 1, and reducing the risk of cracking at the secondary welding position. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram illustrating the connection of copper foil stacks, moving contacts, and external busbars in the prior art. Figure 2 This is a schematic diagram of the moving contact connection assembly provided in Embodiment 1 of the present invention when the moving contact is in the closed position; Figure 3 This is a schematic diagram of the moving contact connection assembly provided in Embodiment 1 of the present invention when the moving contact is in the open position; Figure 4 This is a schematic diagram showing the deformation of the copper foil structure provided in Embodiment 1 of the present invention before and after the moving contact switches between the opening and closing positions. Figure 5 This is a schematic diagram of the copper foil structure provided in Embodiment 1 of the present invention after brazing to form a hard junction. Figure 1 ; Figure 6 This is a schematic diagram of the copper foil structure provided in Embodiment 1 of the present invention after brazing to form a hard junction. Figure 2 ; Figure 7 for Figure 2 Sectional view at AA; Figure 8 This is a schematic diagram of the moving contact connection assembly provided in Embodiment 2 of the present invention when the moving contact is in the closed position; Figure 9 This is a schematic diagram of the moving contact connection assembly provided in Embodiment 3 of the present invention when the moving contact is in the closed position; Figure 10 This is a schematic diagram of the moving contact connection assembly provided in Embodiment 4 of the present invention when the moving contact is in the closed position; Figure 11 This is a schematic diagram of the copper foil structure provided in Embodiment 4 of the present invention; Figure 12 This is a schematic diagram of the structure of the moving contact provided in Embodiment 5 of the present invention; Figure 13 This is a schematic diagram of the moving contact connection assembly provided in Embodiment 5 of the present invention when the moving contact is in the open position; Figure 14 This is a schematic diagram of a mold for preparing copper foil structures provided by the present invention.

[0019] icon: 1-Copper foil structure; 11-First connecting part; 111-First arc segment; 112-First connecting section; 12-Second connecting part; 121-Second arc segment; 122-Second connecting section; 13-Arc transition part; 131-First arc segment; 132-Second arc segment; 2-First fastener; 3-Second fastener; 100-Moving contact; 110-Moving contact point; 120-First positioning groove; 200-External busbar; 210-Second positioning groove. Detailed Implementation

[0020] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] It should be noted that in the description of this invention, the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0022] It should be noted that in the description of this invention, the terms "connection" and "installation" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or a connection through an intermediate medium; they can refer to a mechanical connection or an electrical connection. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0023] Reference Figure 1 In existing connection structures involving copper foil, moving contacts, and external busbars, the copper foil stack is roughly Z-shaped and connected between the moving contact and the external busbar. Each end of the copper foil stack forms a hardened region (the grid area in the diagram) through diffusion brazing, and these two hardened regions are welded to the moving contact and the external busbar, respectively. Significant secondary welding stress exists at the weld points between the hardened regions and the moving contact and external busbar, creating a risk of connection failure due to easy breakage. Furthermore, the roughly Z-shaped copper foil stack causes excessive bending in the area circled in the diagram during the rotation of the moving contact. Excessive bending force leads to easy breakage of the copper foil and a short service life, affecting the performance of the circuit breaker.

[0024] Based on this, the first aspect of this application provides a moving contact connection assembly, referring to... Figures 2 to 13 The moving contact connection assembly includes a copper foil structure 1, which consists of a copper foil sheet (such as...). Figure 5 (as shown) or multiple copper foil sheets stacked together (such as...) Figure 6 The copper foil structure 1 (as shown) comprises a first connecting portion 11, a second connecting portion 12, and an arc-shaped transition portion 13 connecting the first connecting portion 11 and the second connecting portion 12. One end of the first connecting portion 11 away from the arc-shaped transition portion 13 is connected to the first end of the moving contact 100. One end of the second connecting portion 12 away from the arc-shaped transition portion 13 is connected to the external busbar 200. The second end of the moving contact 100 has a moving contact point 110. The rotation center line of the moving contact 100 (…) Figure 2 The cross center line (representing the rotation center of the moving contact 100) is located between the first and second ends of the moving contact 100.

[0025] In the embodiment shown in the accompanying drawings of this application, the middle portion of the arcuate transition portion 13 protrudes toward the second end of the moving contact 100. In some other embodiments, the middle portion of the arcuate transition portion 13 may also protrude away from the second end of the moving contact 100.

[0026] The moving contact 100 has an open position and a closed position, which is rotated by a preset angle relative to the open position. Figure 2 This is a schematic diagram of the moving contact connection assembly when the moving contact 100 is in the closed position, according to one embodiment. Figure 3 This is a schematic diagram of the moving contact connection assembly when the moving contact 100 is in the open position, as shown in one embodiment. Figure 2 and Figure 3 As shown, during the switching of the moving contact 100 between the open and closed positions, the deformation of the copper foil structure 1 is concentrated on the arc-shaped transition portion 13, while the two connecting portions undergo almost only positional changes without bending deformation. The two ends of the arc-shaped transition portion 13 naturally transition and connect with the two connecting portions, and the degree of bending at the connection position is also very small. In other words, the copper foil structure 1 as a whole does not have areas of excessive bending or stress concentration, thereby reducing the risk of damage or even breakage caused by repeated bending of the copper foil structure 1 and improving the service life of the copper foil structure 1.

[0027] Specifically, such as Figure 3 and Figure 4 As shown, during the rotation of the moving contact 100 from the closed position to the open position, the first end of the moving contact 100 gets closer and closer to the external busbar 200, and correspondingly, the distance between the first connecting part 11 and the second connecting part 12 gets closer and closer. During this process, the arc-shaped transition part 13 is subjected to an external force that causes its middle part to bulge away from its centroid. The two ends of the arc-shaped transition part 13 adapt to the distance changes with the two connecting parts. Therefore, there is almost no bending or breakage at the connection points between the two ends of the arc-shaped transition part 13 and the two connecting parts. In addition, when the arc-shaped transition part 13 is subjected to an external force, the force is distributed and transmitted along the tangent of the arc, and the stress concentration phenomenon is greatly reduced. Therefore, the arc-shaped transition part 13 as a whole does not have areas of excessive bending or stress concentration, making the arc-shaped transition part 13 more stable than... Figure 1 The straight structure shown can withstand more bends.

[0028] Furthermore, at least one of the first connecting portion 11 and the second connecting portion 12 is a U-shaped structure formed by bending a copper foil sheet or a stack of copper foil sheets, so that the first connecting portion 11 is riveted to the moving contact 100 and / or the second connecting portion 12 is riveted to the external busbar 200. Riveting is a process in which two or more parts are clamped and fixed using fasteners (usually rivets), and then welded at the riveting point. This application sets at least one end of the copper foil structure 1 into a U-shaped structure, using the U-shaped structure to form a riveting point, thereby allowing the U-shaped end of the copper foil structure 1 to be riveted and fixed. Specifically, after the first connecting portion 11 is assembled and positioned with the moving contact 100 and / or the second connecting portion 12 is connected to the external busbar 200 using fasteners, a welding method such as resistance welding is used, reducing or avoiding secondary welding of the hardened areas on the copper foil structure 1, and lowering the risk of cracking at the secondary welding location. Resistance welding is a pressure welding process that achieves metal connection by applying pressure and resistance heat, which can ensure stable contact between the copper foil structure 1 and the moving contact 100 and the external busbar 200 respectively.

[0029] Reference Figure 4 The included angle α between the faces of the first connecting part 11 and the second connecting part 12 that are respectively close to the centroid of the arc-shaped transition part 13 is denoted as α. When the moving contact 100 is in the closed position, 70° ≤ α ≤ 85°, for example, α is one of 70°, 72°, 76°, 80°, 83°, and 85°. When the moving contact 100 is in the open position, 10° ≤ α ≤ 20°, for example, α is one of 10°, 12°, 14°, 16°, 17°, and 20°. The above parameter range ensures that there are no areas of excessive bending in the copper foil structure 1 as a whole, and at the same time, avoids excessive bending deformation of the arc-shaped transition part 13, thereby further improving the service life of the copper foil structure 1. The selection of the included angle α is directly related to the rotation angle of the moving contact 100, which is directly related to parameters such as the distance between the moving and stationary contacts. The specific parameter of the included angle α needs to be adjusted within the above range according to the actual design requirements.

[0030] Reference Figure 2 In some embodiments, the moving contact 100 is provided with a first positioning groove 120 for the first connecting part 11 to be inserted. The first positioning groove 120 can limit the relative position of the first connecting part 11 and the moving contact 100, thereby facilitating the welding and fixing of the first connecting part 11 and the moving contact 100, and improving the connection strength between the first connecting part 11 and the moving contact 100.

[0031] Reference Figure 9 and Figure 10In some embodiments, the external busbar 200 is provided with a second positioning groove 210 for the second connecting part 12 to be inserted. The second positioning groove 210 can limit the relative position of the second connecting part 12 and the external busbar 200, thereby facilitating the welding and fixing of the second connecting part 12 and the external busbar 200, and improving the connection strength between the second connecting part 12 and the external busbar 200.

[0032] Optionally: the first connecting part 11 has a U-shaped structure and is fixed to the moving contact 100 by riveting; the second connecting part 12 is entirely composed of a hardened area and is fixed to the external busbar 200 by welding; or, the second connecting part 12 has a U-shaped structure and is fixed to the external busbar 200 by riveting; the first connecting part 11 is entirely composed of a hardened area and is fixed to the moving contact 100 by welding; or, both the first connecting part 11 and the second connecting part 12 have U-shaped structures, and are respectively fixed to the moving contact 100 and the external busbar 200 by riveting. In summary, at least one of the first connecting part 11 and the second connecting part 12 has a U-shaped structure.

[0033] When the first connecting portion 11 is fixed to the moving contact 100 by riveting or welding, the first connecting portion 11 includes a first arc segment 111 and first connecting segments 112 extending from both ends of the first arc segment 111. The moving contact connecting assembly also includes a first fastener 2 connected to the moving contact 100, and the first arc segment 111 is pressed between the first fastener 2 and the moving contact 100. The first fastener 2 is preferably a rivet, but it can also be a non-standard part such as a pin.

[0034] When the second connecting part 12 is fixed to the external busbar 200 by riveting or welding, the second connecting part 12 includes a second arc segment 121 and second connecting segments 122 extending from both ends of the second arc segment 121. The moving contact connecting assembly also includes a second fastener 3 connected to the external busbar 200, and the second arc segment 121 is pressed between the second fastener 3 and the external busbar 200. The second fastener 3 is preferably a rivet, but it can also be a non-standard part such as a pin.

[0035] It should be noted that the two ends of the copper foil structure 1 are welded and fixed to the moving contact 100 and the external busbar 200, respectively, and the deformation of the copper foil structure 1 is concentrated in its middle. During the rotation of the moving contact 100, the part of the copper foil structure 1 near the welding point will form a small connecting segment that almost only shifts without deforming under the constraint of the welding. In actual use, the connecting segment is generally a curve or a straight line with a very small curvature. In this application, for the convenience of describing the included angle α, the connecting segment is approximated as a straight line.

[0036] In some embodiments, the copper foil sheet is a long, rectangular sheet. Compared to traditional irregularly shaped copper foil, setting the copper foil sheet as a rectangular sheet can save mold costs.

[0037] To ensure that the prepared copper foil structure 1 meets the shape and curvature requirements described above, a structure like this can be fabricated. Figure 14 The mold shown has grooves machined on it to match the outer contour design shape of the copper foil structure 1. During the preparation of the copper foil structure 1, copper foil sheets or stacks are placed into the grooves and shaped so that the outer contour of the copper foil sheets or stacks fits the groove wall. After the copper foil sheets or stacks are shaped, diffusion brazing is performed on the ends of the copper foil sheets or stacks to ensure that the contour dimensions of the copper foil structure 1 meet the design requirements.

[0038] The following are several specific embodiments provided in this application.

[0039] Example 1 Reference Figures 2 to 4 In this embodiment, the preset rotation angle of the moving contact 100 is 58°; when the moving contact 100 is in the closed position, a=76°; when the moving contact 100 is in the open position, a=16°.

[0040] Furthermore, referring to Figures 4 to 6 The two ends of a copper foil sheet or stack of copper foil sheets along its length are bent and then welded to form a hardened region (the grid area in the figure). The end of the copper foil structure 1 away from the hardened region is naturally bent to form a U-shaped structure. The hardened region constitutes one of the first connecting part 11 and the second connecting part 12, while the U-shaped structure constitutes the other. In this embodiment, the U-shaped structure constitutes the first connecting part 11 and is fixed to the moving contact 100 by riveting, and the hardened region constitutes the second connecting part 12 and is fixed to the external busbar 200 by welding. Of course, in other embodiments, the hardened region can also be fixed to the moving contact 100 by welding, and the U-shaped structure can be fixed to the external busbar 200 by riveting.

[0041] Compared to existing designs where each end of a copper foil stack forms a hard knot, the copper foil structure 1 in this embodiment is manufactured by bending and welding the ends of the copper foil sheet or copper foil stack together. The copper foil structure 1 is generally annular with only one hard knot area. This reduces the welding stress between the hard knot area on the copper foil structure 1 and the moving contact and external busbar, lowering the risk of connection failure. It also reduces one brazing step, lowering welding costs. Furthermore, compared to welding the hard knot area of ​​the copper foil structure 1 to the moving contact 100, this embodiment uses riveting to fix the copper foil structure 1 and the moving contact 100, avoiding secondary welding stress and allowing the connection strength to withstand more moving contact position switching cycles.

[0042] Continue to refer to Figure 4 The first connecting part 11 includes two first connecting segments 112, which are respectively the first connecting segment I and the first connecting segment II; the second connecting part 12 includes two second connecting segments 122, which are respectively the second connecting segment I and the second connecting segment II; the arc-shaped transition part 13 includes a first arc segment 131 and a second arc segment 132, which surrounds the side of the first arc segment 131 away from its centroid; the first connecting segment I, the first arc segment 131 and the second connecting segment I are connected in sequence, and the first connecting segment II, the second arc segment 132 and the second connecting segment II are connected in sequence; the included angle between the first connecting segment I and the second connecting segment I is α, and the included angle between the first connecting segment II and the second connecting segment II is b, where b > α.

[0043] Since the first connecting portion 11 has a U-shaped structure, the first connecting portion 11 also includes a first arc segment 111 connecting the two first connecting segments 112. The two second connecting segments 122 in the second connecting portion 12 are stacked and fixed together by diffusion brazing.

[0044] Reference Figure 7 The moving contact 100 is provided with a first positioning groove 120 for the first connecting part 11 to be inserted, and the bottom of the first positioning groove 120 is provided with a riveting hole. The first fastener 2 is specifically a rivet, which passes through the riveting hole and clamps the first connecting part 11 between the bottom of the first positioning groove 120 and the rivet head. The first fastener 2, the first connecting part 11 and the moving contact 100 are riveted and welded together by resistance welding or other methods.

[0045] Example 2 The main difference between this embodiment and Embodiment 1 is that the copper foil structure 1 is manufactured in a different way. In this embodiment, the copper foil structure 1 is composed of multiple copper foil sheets stacked together, and the two ends of the copper foil sheets are not connected together.

[0046] Reference Figure 8 In this embodiment, one end of the copper foil stack is welded to form a hardened region, and the other end of the copper foil stack is bent to form a U-shaped structure. The U-shaped structure constitutes the first connecting part 11 and is fixed to the moving contact 100 by riveting. The hardened region constitutes the second connecting part 12 and is fixed to the external busbar 200 by welding.

[0047] Furthermore, the first connecting portion 11 includes a first arc segment 111 and a first connecting segment I and a first connecting segment II extending from both ends of the first arc segment 111, wherein: the first arc segment 111 is pressed between the first fastener 2 and the moving contact 100, and the three are fixed by welding; the first connecting segment I is transitionally connected between the first arc segment 111 and the arc-shaped transition portion 13; the first connecting segment II can form a hardened area by welding.

[0048] In this embodiment, diffusion brazing is performed on both ends of the copper foil stack, forming a hardened region at each end. These two hardened regions constitute the first connecting segment II and the second connecting portion 12, respectively. This arrangement makes the copper foil structure 1 a unified whole, preventing it from becoming scattered and facilitating welding of the copper foil structure 1 to the moving contact 100 and its storage. Simultaneously, the first connecting segment II (hardened region) avoids the riveting positions between the copper foil structure 1 and the moving contact 100, thus preventing secondary welding stress between them.

[0049] The remaining structure of this embodiment is the same as that of Embodiment 1, and will not be described again here.

[0050] Example 3 The main difference between this embodiment and embodiment two is that the two ends of the copper foil sheet or copper foil stack in this embodiment are bent to form a U-shaped structure, that is, the two ends of the copper foil structure 1 are respectively hook-shaped.

[0051] Reference Figure 9 In this embodiment, the first connecting part 11 and the moving contact 100, as well as the second connecting part 12 and the external busbar 200, are fixed by riveting and welding. Specifically, the second connecting part 12 includes a second arc segment 121 and second connecting segments 122 extending from both ends of the second arc segment 121. The second arc segment 121 is pressed between the second fastener 3 and the external busbar 200. The external busbar 200 is provided with a second positioning groove 210 for the second connecting part 12 to be inserted, and the bottom of the second positioning groove 210 is provided with a riveting hole. The second fastener 3 is specifically a rivet. The second fastener 3 passes through the riveting hole on the external busbar 200 and clamps the second connecting part 12 between the bottom of the second positioning groove 210 and the rivet head. The second fastener 3, the second connecting part 12, and the external busbar 200 are riveted and welded together by resistance welding or other methods. The structure of the first connecting part 11 is the same as in Embodiment 2, and will not be described again.

[0052] Furthermore, the two second connecting segments 122 are respectively the second connecting segment I and the second connecting segment II. The second connecting segment I is transitionally connected between the second arc segment 121 and the arc-shaped transition portion 13; the second connecting segment II can form a hardened region through welding.

[0053] The remaining structure of this embodiment is the same as that of Embodiment 2, and will not be described again here.

[0054] Example 4 In this embodiment, the two ends of the copper foil sheet or copper foil stack along its length are bent and joined together to form a hardened region. The main difference from Embodiment 1 is that the hardened region on the copper foil structure 1 in this embodiment is offset from the welding point, and the hardened region is not welded to the moving contact and the external busbar. In this way, there is no secondary welding stress at either end of the copper foil structure 1, further reducing the risk of connection failure of the copper foil structure 1.

[0055] Reference Figure 10 and Figure 11 In this embodiment, the first connecting portion 11 and the moving contact 100, and the second connecting portion 12 and the external busbar 200 are both fixed by riveting and welding. The hardened area on the copper foil structure 1 is located in the second connecting portion 12; of course, the hardened area can also be located in the first connecting portion 11. Figure 4 As can be seen, during the rotation of the moving contact 100, the closer to the solder joint, the less likely the copper foil structure 1 is to bend under the welding constraint. By placing the hardened area in the second connection part 12 and near the solder joint, the bending force on the hardened area is avoided, and the problem of easy breakage near the hardened area due to high stress during secondary welding is also avoided.

[0056] The remaining structure of this embodiment is the same as that of Embodiment 1, and will not be described again here.

[0057] Example 5 This embodiment is an extension based on any of the above embodiments.

[0058] In embodiments one through four, after the copper foil structure 1 is bent many times, the copper foil sheet will deform, causing the actual shape and curvature of the copper foil structure 1 to no longer meet its initial shape and curvature, and even local over-bent areas (i.e., obvious bending lines) will appear. Based on this, referring to Figure 12 and Figure 13 In this embodiment, the first end of the moving contact 100 has a shaping portion 130, which has a shaping arc surface facing the copper foil structure 1; the shaping arc surface is configured such that when the moving contact 100 is in the open position (i.e. Figure 13 (as shown in the figure) the shaped arc surface fits into the side of the arc transition portion 13 closest to its centroid so that the curvature of the arc transition portion 13 meets the design requirements.

[0059] In this embodiment, a shaping part 130 is formed on the moving contact 100. The shaping part 130 is used to shape the copper foil structure 1 each time the circuit breaker is opened, so that the shape and curvature of the copper foil structure 1 will not be deformed after multiple bends, thereby ensuring the long-term performance of the copper foil structure 1 and improving its service life.

[0060] Performance testing right Figure 1 The prior art shown and embodiments one to four above were subjected to mechanical life tests to test the number of times the moving contact position switched when the copper foil broke. The test results are shown in the table below.

[0061]

[0062] Practical verification shows that the mechanical bending life of the moving contact connection assembly provided in this application is at least 10,000 cycles, which is at least 10 times better than the prior art. Furthermore, this moving contact connection assembly also has advantages such as simple structure, low cost, and high adaptability (compatible with all types of circuit breakers).

[0063] A second aspect of this application provides a circuit breaker, which includes a moving contact connection assembly, a moving contact 100, and an external busbar 200 as provided in any of the above embodiments. This circuit breaker possesses all the technical features and effects of the aforementioned moving contact connection assembly, which will not be repeated here.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A moving contact connection assembly, characterized in that, The system includes a copper foil structure (1), which is composed of a copper foil sheet or a copper foil stack of multiple copper foil sheets. The copper foil structure (1) includes a first connecting part (11), a second connecting part (12), and an arc-shaped transition part (13) connecting the first connecting part (11) and the second connecting part (12). The end of the first connecting part (11) away from the arc-shaped transition part (13) is connected to the first end of the moving contact (100), and the end of the second connecting part (12) away from the arc-shaped transition part (13) is connected to the external busbar (200). The second end of the moving contact (100) has a moving contact point (110), and the rotation center line of the moving contact (100) is located between the first end and the second end of the moving contact (100). At least one of the first connecting part (11) and the second connecting part (12) is a U-shaped structure formed by bending the copper foil or the copper foil stack, so that the first connecting part (11) is assembled and positioned with the moving contact (100) and / or the second connecting part (12) is assembled and positioned with the external busbar (200) by fasteners, and then connected together by welding.

2. The moving contact connection assembly according to claim 1, characterized in that, The moving contact (100) has a closed position and a closed position that is rotated by a preset angle relative to the closed position. The included angle between the faces of the first connecting part (11) and the second connecting part (12) that are respectively close to the centroid of the arc-shaped transition part (13) is α. When the moving contact (100) is in the closed position, 70°≤a≤85°; When the moving contact (100) is in the open position, 10°≤a≤20°.

3. The moving contact connection assembly according to claim 2, characterized in that, The preset angle for the rotation of the moving contact (100) is 58°; When the moving contact (100) is in the closed position, a = 76°; When the moving contact (100) is in the open position, a = 16°.

4. The moving contact connection assembly according to any one of claims 1 to 3, characterized in that, The two ends of the copper foil along its length are bent and joined together to form a hardened region, which is located at the first connecting part (11) or the second connecting part (12); and / or, The first connecting portion (11) includes a first arc segment (111) and first connecting segments (112) extending from both ends of the first arc segment (111). The moving contact connecting assembly further includes a first fastener (2) connected to the moving contact (100). The first arc segment (111) is pressed between the first fastener (2) and the moving contact (100); and / or, The second connecting part (12) includes a second arc segment (121) and a second connecting segment (122) extending from both ends of the second arc segment (121). The moving contact connecting assembly also includes a second fastener (3) connected to the external busbar (200). The second arc segment (121) is pressed between the second fastener (3) and the external busbar (200).

5. The moving contact connection assembly according to any one of claims 1 to 3, characterized in that, The first connecting part (11) includes a first connecting segment I and a first connecting segment II, the second connecting part (12) includes a second connecting segment I and a second connecting segment II, the arc transition part (13) includes a first arc segment (131) and a second arc segment (132), the second arc segment (132) surrounds the side of the first arc segment (131) away from its centroid, the first connecting segment I, the first arc segment (131) and the second connecting segment I are connected in sequence, the first connecting segment II, the second arc segment (132) and the second connecting segment II are connected in sequence; The included angle between the first connecting segment I and the second connecting segment I is a, and the included angle between the first connecting segment II and the second connecting segment II is b, where b > a.

6. The moving contact connection assembly according to any one of claims 1 to 3, characterized in that, The moving contact (100) is provided with a first positioning groove (120) for the first connecting part (11) to be inserted; and / or, The external busbar (200) is provided with a second positioning groove (210) for the second connecting part (12) to be inserted.

7. The moving contact connection assembly according to claim 4, characterized in that, The first fastener (2) and / or the second fastener (3) are rivets; and / or, The first fastener (2), the first connecting part (11), and the moving contact (100) are welded together by riveting; and / or, The second fastener (3), the second connecting part (12) and the external busbar (200) are welded together by riveting.

8. The moving contact connection assembly according to claim 1, characterized in that, The two ends of the copper foil sheet or the stack of copper foil sheets along its length direction are bent and then welded to form a hardened region. The end of the copper foil structure (1) away from the hardened region is naturally bent to form the U-shaped structure. The hardened region is fixed to the external busbar (200) by welding. The U-shaped structure is fixed to the moving contact (100) by riveting. The copper foil sheet or the copper foil stack has its two ends bent and joined together to form a hardened region along its length, and the two ends of the copper foil structure (1) respectively form the U-shaped structure. The hardened region is offset from the welding positions of the copper foil structure (1) with the moving contact (100) and the external busbar (200); or, The copper foil structure (1) is composed of copper foil stacks. One end of the copper foil stacks is welded to form a hardened region, and the other end of the copper foil stacks is bent to form the U-shaped structure. The hardened region is welded to the external busbar (200), and the U-shaped structure is riveted to the moving contact (100); or, The two ends of the copper foil sheet or the copper foil stack are bent to form the U-shaped structure, and are respectively fixed to the moving contact (100) and the external busbar (200) by riveting.

9. The moving contact connection assembly according to claim 1, characterized in that, The middle part of the arc-shaped transition portion (13) protrudes toward or away from the second end of the moving contact (100); The copper foil sheet is a long, rectangular sheet.

10. A circuit breaker, characterized in that, Includes the moving contact connection assembly as described in any one of claims 1 to 9.

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