Contact system and molded case circuit breaker

Abstract

The utility model provides a contact system and a molded case circuit breaker, and belongs to the technical field of electrical equipment. The contact system provided by the utility model comprises a static contact and a moving contact. The static contact comprises a fixed part and a contact part which are connected with each other, the contact part comprises a first straight section, a first bent section and a second straight section which are connected in sequence, the first bent section is bent towards the fixed part, and the second straight section is located on one side of the first straight section. The moving contact is partially arranged on one side, far away from the fixed part, of the contact part, the moving contact comprises a moving feeler lever, and when the moving contact is conducted with the static contact, the first straight section is located between the moving feeler lever and the second straight section. Through the arrangement, the attraction force of the first straight section to the movable feeler lever can counteract part of the repulsive force of the second straight section to the movable feeler lever. Therefore, the separation efficiency of the moving contact can be reduced, response time can be provided for a fault miniature circuit breaker connected with the molded case circuit breaker, and the probability of large-scale power failure can be reduced.

Description

Technical Field

[0001] This application relates to the field of electrical equipment technology, and in particular to a contact system and a molded case circuit breaker. Background Technology

[0002] Molded case circuit breakers (MCCBs) are widely used circuit protection devices in electrical systems. They offer multiple functions including automatic protection, manual control, and circuit breaker detection, enabling them to promptly disconnect power in the event of overload, short circuit, or earthquake faults, thus ensuring equipment and personnel safety.

[0003] Molded case circuit breakers (MCCBs) are typically connected to multiple miniature circuit breakers (MPBs). When one of the MPBs experiences a short circuit, the internal circuit of the MCCB is broken, causing all the MPBs connected to the MCCB to lose power, resulting in a large-scale power outage. Utility Model Content

[0004] This application provides a contact system and a molded case circuit breaker to reduce the probability of large-scale power outages.

[0005] In a first aspect, this application provides a contact system including a stationary contact and a moving contact. The stationary contact includes a fixed portion and a contact portion connected to each other. The contact portion includes a first straight section, a first bent section, and a second straight section connected in sequence. The first bent section bends towards the fixed portion, and the second straight section is located on one side of the first straight section. The moving contact portion is disposed on the side of the contact portion away from the fixed portion. The moving contact includes a moving contact rod. When the moving contact contacts the stationary contact, the first straight section is located between the moving contact rod and the second straight section.

[0006] With the above solution, when the moving contact and stationary contact are in contact, the first straight section is located between the moving contact rod and the second straight section, making the first straight section closer to the moving contact rod than the second straight section. Since the current flow direction in the first straight section is the same as that in the moving contact rod, while the current flow direction in the second straight section is opposite, the attractive force of the first straight section on the moving contact rod can partially offset the repulsive force of the second straight section. Thus, when fault current flows through the stationary and moving contacts, the separation efficiency of the moving contact can be reduced. When the separation efficiency of the moving contact is reduced, it provides reaction time for the miniature circuit breaker connected to the molded case circuit breaker, thereby reducing the probability of large-scale power outages.

[0007] In one possible design, the first bend is U-shaped. The end of the first bend that connects to the second straight section is bent toward the side away from the moving contact.

[0008] With the above solution, the end connecting the first bent section and the second straight section is bent towards the side away from the moving contact. This allows the second straight section to be positioned further away from the moving contact rod compared to the first straight section, thus achieving the effect of the first straight section being closer to the moving contact rod than the second straight section. Because the first straight section is closer to the moving contact rod, the attractive force between them is stronger, better counteracting the repulsive force between the second straight section and the moving contact rod.

[0009] In one possible design, the first bend is shaped like a vertical line.

[0010] The above solution simplifies the manufacturing of the first bent section. Furthermore, the first bent section also achieves the effect of positioning the second straight section further away from the moving contact rod compared to the first straight section.

[0011] In one possible design, the contact portion is provided with a guide groove. The guide groove extends through the contact portion along the arrangement direction of the first straight section and the second straight section.

[0012] Through the above scheme, the guide groove penetrates the contact portion, dividing the originally monolithic first straight section into two parallel first straight sections. This splits the single current within the first straight section into two currents, both flowing in the same direction as the current within the moving contact rod. Because the guide groove penetrates the first straight section, dividing it into two parallel plate-like structures, the area of ​​the first straight section is reduced. This reduces the dispersion of current flowing through the first straight section, increasing the attractive force of the first straight section on the moving contact rod, and further counteracting the repulsive force of the second straight section on the moving contact rod. This further reduces the separation efficiency of the moving contact.

[0013] In one possible design, the fixing part includes a second bent section. The second bent section is bent away from the direction of the moving contact. The second bent section is connected to the end of the first straight section away from the first bent section.

[0014] The above solution allows the stationary contact to be installed inside the molded case circuit breaker. The second bend section makes the connection between the stationary and contact parts more suitable for the installation environment inside the housing, reducing the difficulty of installing the stationary contact inside the housing. Furthermore, the bending angle of the second bend section can be selected according to actual usage requirements, broadening the applicability of the stationary contact and further reducing the difficulty of installing it inside the housing.

[0015] In one possible design, the fixing part is provided with a mounting hole, which is a circular through hole.

[0016] The above solution provides a mounting base for the fixing part by setting the mounting hole. When the mounting hole is a circular through hole, its shape can better match the shape of the bolt, reducing the installation difficulty of the stationary contact. Furthermore, when the shape of the mounting hole matches the bolt, the bolt installation is more stable, reducing the possibility of the stationary contact falling out of the housing due to bolt loosening, and improving the reliability of the contact system.

[0017] In one possible design, the stationary contact includes a contact seat. The contact seat is disposed on the second straight section and is oriented toward the moving contact. A stationary contact is provided on the contact seat.

[0018] The above solution provides installation space for the stationary contact, ensuring its secure mounting on the stationary contact head. This reduces the probability of the stationary contact falling off, increasing the reliability of the contact system. Furthermore, the contact seat provides positioning for the stationary contact, simplifying installation and improving efficiency.

[0019] In one possible design, the contact seat has an extension section. The extension section extends toward the fixing part.

[0020] The above solution addresses the issue of electric arcs generated during the opening of molded case circuit breakers. The extension section allows the arc to be transferred from the stationary contact to the extension section, thus reducing the time the arc spends eroding the stationary contact. Reduced arc erosion time decreases the wear on the stationary contact, eliminating the need for frequent replacements and lowering the overall operating cost of the contact system.

[0021] In one possible design, the contact system also includes a stationary cover. The stationary cover is disposed over the contact portion.

[0022] By employing the above-described method, since the stationary cover is typically made of insulating material, when it is placed over the contact portion, the probability of the arc shifting towards the moving contact can be reduced, thus decreasing the arc dwell time between the stationary and moving contacts. This improves the arc-extinguishing efficiency of the molded case circuit breaker.

[0023] Secondly, this application provides a molded case circuit breaker, which includes a housing and the contact system mentioned in the first aspect. An installation space is provided inside the housing. The contact system is located within the installation space.

[0024] The beneficial effects of the molded case circuit breaker provided in the second aspect above can be found in the first aspect and the beneficial effects of various possible embodiments of the first aspect, and will not be repeated here. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of the molded case circuit breaker provided in the embodiments of this application.

[0026] Figure 2 This is a schematic diagram of the structure of the stationary contact provided in an embodiment of this application.

[0027] Figure 3 This is a schematic diagram of the contact between the moving contact and the stationary contact provided in an embodiment of this application.

[0028] Figure 4 for Figure 3 Diagram showing the current flow in the moving and stationary contacts.

[0029] Figure 5 The diagram showing the current flow between the moving and stationary contacts when the first bending segment is of the I-shape is provided for the embodiments of this application.

[0030] Explanation of reference numerals in the attached figures:

[0031] 100. Stationary contact; 110. Fixing part; 111. Second bending section; 112. Mounting hole; 120. Contact part; 121. First straight section; 122. First bending section; 123. Second straight section; 124. Contact seat; 125. Flow guide groove;

[0032] 200. Moving contact; 210. Moving contact rod;

[0033] 300. Shell. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein in the specification of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0036] The terms "comprising" and "having," and any variations thereof, used in the specification, claims, and drawings of this application are intended to cover without excluding other meanings. The words "a" or "an" do not exclude the presence of multiples.

[0037] The term "embodiment" as used herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of the phrase "embodiment" in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0038] In this article, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0039] The directional terms appearing in the following description refer to the directions shown in the figures and are not intended to limit the specific structure of this application. For example, in the description of this application, terms such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figures. They are used only for the convenience of describing this application and 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 this application.

[0040] Furthermore, the terms "first," "second," etc., in the specification and claims of this application or in the aforementioned drawings are used to distinguish different objects rather than to describe a specific order, and may explicitly or implicitly include one or more of the features.

[0041] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, "connection" or "joining" in mechanical structures can refer to a physical connection. A physical connection can be a fixed connection, such as a connection secured by fasteners, such as a connection secured by screws, bolts, or other fasteners; a physical connection can also be a detachable connection, such as a snap-fit ​​or interlocking connection; a physical connection can also be an integral connection, such as a connection formed by welding, bonding, or integral molding. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0042] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0043] Figure 1 This is a schematic diagram of the overall structure of the molded case circuit breaker provided in the embodiments of this application. Figure 2 This is a schematic diagram of the structure of the stationary contact provided in an embodiment of this application. Figure 3 This is a schematic diagram illustrating the contact between the moving contact and the stationary contact provided in an embodiment of this application. Figures 1 to 3 As shown, this application provides a molded case circuit breaker, which includes a housing 300 and a contact system. The housing 300 has an internal mounting space. The contact system is located within the mounting space.

[0044] The housing 300 includes a top cover and a base. The base has an internal mounting space, and the contact system is installed in the mounting space inside the base. The top cover can be placed on the base to protect the contact system.

[0045] A molded case circuit breaker typically contains multiple moving contacts 200 and multiple stationary contacts 100. A single moving contact 200 and a single stationary contact 100 can form a contact system. All stationary contacts 100 are fixedly mounted within a base. A contact support is also provided within the housing 300. Multiple moving contacts 200 share a single contact support, which enables the moving contacts 200 to rotate, allowing them to contact or separate from the stationary contacts 100.

[0046] As described above, multiple contact systems can be installed inside a molded case circuit breaker, which allows multiple miniature circuit breakers to be connected in parallel simultaneously.

[0047] However, if one of the miniature circuit breakers experiences a short circuit, the short-circuit current will first flow through the contact system of the molded case circuit breaker connected to the short-circuited miniature circuit breaker. Since multiple moving contacts 200 inside the molded case circuit breaker share a single contact support, when one moving contact 200 in one set of contact systems separates from the stationary contact 100, the remaining moving contacts 200 will also separate from their corresponding stationary contacts 100. This will cause multiple miniature circuit breakers connected in parallel with the molded case circuit breaker to lose power simultaneously, resulting in a large-scale power outage.

[0048] This application improves the contact system to reduce the probability of the above-mentioned problems occurring. The contact system mentioned in this application will be clearly and completely described below with reference to the accompanying drawings.

[0049] like Figures 1 to 3As shown, this application provides a contact system including a stationary contact 100 and a moving contact 200. The stationary contact 100 includes a fixed portion 110 and a contact portion 120 connected to each other. The contact portion 120 includes a first straight section 121, a first bent section 122, and a second straight section 123 connected in sequence. The first bent section 122 bends toward the fixed portion 110, and the second straight section 123 is located on one side of the first straight section 121. The moving contact 200 is partially disposed on the side of the contact portion 120 away from the fixed portion 110. The moving contact 200 includes a moving contact rod 210. When the moving contact 200 contacts the stationary contact 100, the first straight section 121 is located between the moving contact rod 210 and the second straight section 123.

[0050] The stationary contact 100 can be made of a highly conductive material such as copper or silver. The stationary contact 100 comprises two interconnected parts. One part is a fixing part 110, which secures the stationary contact 100 within the housing 300. The other part is a contact part 120, on which a stationary contact point may be provided.

[0051] Both the first straight segment 121 and the second straight segment 123 can be elongated plate-like structures. One end of the first bent segment 122 is connected to the end of the first straight segment 121 away from the fixing part 110, and the other end is connected to the second straight segment 123. The first straight segment 121 can be parallel to the second straight segment 123. Alternatively, the first straight segment 121 and the second straight segment 123 can have a certain angle between them. The stationary contact can be located on the second straight segment 123.

[0052] The moving contact rod 210 can be a long strip-shaped structure, including a first end and a second end that are positioned opposite each other. The first end of the moving contact rod 210 can be fixedly connected to the contact support, and the second end of the moving contact rod 210 can be provided with a moving contact. When the contact support drives the moving contact 200 to rotate, the moving contact rod 210 can drive the moving contact to contact or separate from the stationary contact.

[0053] The current flow direction within a molded case circuit breaker can be divided into two scenarios. Scenario 1: The current flowing into the molded case circuit breaker first enters the stationary contact 100, then flows out from the moving contact 200 to the next stage miniature circuit breaker. Scenario 2: The current flowing into the molded case circuit breaker first enters the moving contact 200, then flows out from the stationary contact 100 to the next stage miniature circuit breaker. The following explanation will only use the first scenario as an example.

[0054] Figure 4 for Figure 3 Diagram showing the current flow within the moving and stationary contacts. (See diagram below.) Figure 4As shown, when the moving contact comes into contact with the stationary contact, the moving contact 200 and the stationary contact 100 are connected, and the current can flow through the stationary contact 100 into the moving contact rod 210. Due to the setting of the first bending section 122, the current first flows through the first straight section 121, then through the first bending section 122, and finally through the second straight section 123. When the current flows through the second straight section 123, it can flow into the moving contact rod 210 through the stationary contact set on the second straight section 123 and the moving contact set on the moving contact rod 210.

[0055] The first bent section 122 bends toward the fixed part 110. The moving contact 200 is partially disposed on the side of the contact part 120 away from the fixed part 110. When the first straight section 121 is located between the moving contact rod 210 and the second straight section 123, the current flowing into the first straight section 121 flows in the same direction as the current flowing into the moving contact rod 210, and the current flowing into the second straight section 123 flows in the opposite direction to the current flowing into the moving contact rod 210.

[0056] Based on the principle that currents in the same direction attract each other and currents in opposite directions repel each other, it can be concluded that since the first straight section 121 is closer to the moving contact 210 than the second straight section 123, the attractive force of the first straight section 121 on the moving contact 210 can partially offset the repulsive force of the second straight section 123 on the moving contact 210. Therefore, when a short-circuit current flows through the stationary contact 100 and the moving contact 200, the moving contact 200 and the stationary contact 100 will not immediately separate.

[0057] Because of the high current flow rate, the fault current has already flowed into the next-level faulty miniature circuit breaker before the moving contact 200 and stationary contact 100 inside the molded case circuit breaker have separated. At this time, the faulty miniature circuit breaker trips. In this way, the contact system connected to the tripped miniature circuit breaker inside the molded case circuit breaker will not trip again, the contact supports inside the molded case circuit breaker will not rotate again, and the other contact systems inside the molded case circuit breaker will not trip. Correspondingly, the other miniature circuit breakers except the faulty miniature circuit breaker will not experience power outages, thereby reducing the probability of large-scale power outages.

[0058] In summary, when the moving contact 200 and the stationary contact 100 are in contact, the first straight section 121 is located between the moving contact rod 210 and the second straight section 123, so the first straight section 121 is closer to the moving contact rod 210 than the second straight section 123. Since the current flow direction in the first straight section 121 is the same as that in the moving contact rod 210, and the current flow direction in the second straight section 123 is opposite to that in the moving contact rod 210, the attractive force of the first straight section 121 on the moving contact rod 210 can partially offset the repulsive force of the second straight section 123 on the moving contact rod 210. Thus, when the fault current flows through the stationary contact 100 and the moving contact 200, the separation efficiency of the moving contact 200 can be reduced. When the separation efficiency of the moving contact 200 is reduced, it provides reaction time for the miniature circuit breaker connected to the molded case circuit breaker, thereby reducing the probability of large-scale power outages.

[0059] The first bending segment 122 can be set in several ways. The following describes two of these settings in detail with reference to the attached diagram.

[0060] The first setting is as follows: Figure 4 As shown, the first bending segment 122 is U-shaped. The end of the first bending segment 122 that connects to the second straight segment 123 is bent toward the side away from the moving contact 200.

[0061] The opening direction of the first bending section 122 can face the fixing part 110. The first bending section 122 can include an inlet arc section, a transition section, and an outlet arc section. Because the opening direction of the first bending section 122 faces the fixing part 110, both the inlet arc section and the outlet arc section can face the fixing part 110. Current can enter the inlet arc section from the first straight section 121, enter the outlet arc section through the transition section, and then enter the second straight section 123 from the outlet arc section.

[0062] When the first configuration is selected, the end connecting the first bent segment 122 and the second straight segment 123 is bent towards the side away from the moving contact 200. This allows the second straight segment 123 to be further away from the moving contact rod 210 compared to the first straight segment 121. This achieves the effect that the first straight segment 121 is closer to the moving contact rod 210 than the second straight segment 123. The closer the first straight segment 121 is to the moving contact rod 210, the stronger the attraction between them, which better counteracts the repulsive force between the second straight segment 123 and the moving contact rod 210.

[0063] Figure 5 The diagram shows the current flow between the moving and stationary contacts when the first bent section is of the I-shape, as provided in the embodiments of this application. The second configuration is as follows... Figure 5 As shown, the first bend segment 122 is in the shape of a vertical bar.

[0064] The end of the first straight section 121 away from the fixed part 110 can be connected to the end of the first bent section 122 near the moving contact rod 210, and the end of the second straight section 123 away from the fixed part 110 can be connected to the end of the first bent section 122 away from the moving contact rod 210, so that the first straight section 121 can be located between the second straight section 123 and the moving contact rod 210.

[0065] When the second configuration is selected, the manufacturing of the first bent section 122 is simpler. Furthermore, the first bent section 122 can also achieve the effect of making the second straight section 123 farther away from the moving contact rod 210 compared to the first straight section 121.

[0066] like Figure 2 As shown, the contact portion 120 may be provided with a guide groove 125. The guide groove 125 may penetrate the contact portion 120 along the thickness direction of the contact portion 120.

[0067] The flow guide 125 can be configured in several ways. For example, in the first configuration, the flow guide 125 can penetrate the first straight section 121 only in the thickness direction of the contact portion 120. In the second configuration, the flow guide 125 can penetrate both the first straight section 121 and the second straight section 123 in the thickness direction of the contact portion 120.

[0068] Regardless of whether the first or second setting is selected, the guide groove 125 can penetrate the first bend section 122 along the thickness direction of the first bend section 122.

[0069] The guide channel 125 can divide the originally integral first straight section 121 into two parallel plate-like structures. At this time, the moving contact rod 210 can be located between the two parallel plate-like structures. The current flow direction in both parallel plate-like structures is the same as the current flow direction in the moving contact rod 210.

[0070] With the above configuration, the guide groove 125 penetrates the contact portion 120, dividing the originally monolithic first straight section 121 into two parallel first straight sections 121. This splits the single current within the first straight section 121 into two currents, both flowing in the same direction as the current within the moving contact rod 210. Because the guide groove 125 penetrates the first straight section 121, dividing it into two parallel plate-like structures, the area of ​​the first straight section 121 is reduced. This reduces the dispersion of current flowing through the first straight section 121, increasing the attractive force of the first straight section 121 on the moving contact rod 210, further counteracting the repulsive force of the second straight section 123 on the moving contact rod 210. This further reduces the separation efficiency of the moving contact 200.

[0071] To facilitate the installation of the stationary contact 100, this application also improves the fixing part 110, such as... Figure 1 as well as Figure 2 As shown, the fixing part 110 includes a second bent section 111. The second bent section 111 is bent in a direction away from the moving contact 200. The second bent section 111 is connected to the end of the first straight section 121 away from the first bent section 122.

[0072] The fixing part 110 can be connected to the circuit of the molded case circuit breaker. When the molded case circuit breaker is in the closed state, the current in the circuit flows through the fixing part 110 and then through the second bending section 111 to the contact part 120.

[0073] A mounting platform may be provided inside the housing 300 of the molded case circuit breaker. The mounting platform is positioned higher than the contact portion 120. In this case, a second bending section 111 can be provided in the fixing portion 110 to better fit the mounting platform. By bending the second bending section 111 in a direction away from the moving contact 200, the end of the first straight section 121 near the fixing portion 110 can be connected to the fixing portion 110 via the second bending section 111.

[0074] The fixing part 110 may also be provided with a mounting hole 112, which may be a circular through hole with a smooth inner wall. A positioning hole may be provided on the mounting platform inside the housing 300. The position of the positioning hole may be opposite to that of the mounting hole 112, and the inner wall of the positioning hole may be provided with threads.

[0075] When the stationary contact 100 is installed inside the molded case circuit breaker, the fixing part 110 can be placed on the mounting platform first, with the contact part 120 aligned with the moving contact 200. Then, the mounting hole 112 should be aligned with the positioning hole, and a bolt should be passed through the mounting hole 112 and threaded into the positioning hole. Alternatively, when installing the stationary contact 100, a perforated shim can be placed on the side of the fixing part 110 away from the mounting platform, with the hole on the shim aligned with the mounting hole 112, before installing the bolt. This increases the stability after bolt installation, thereby increasing the stability of the stationary contact 100 during installation.

[0076] When the mounting hole 112 is a circular through hole, the shape of the mounting hole 112 can better match the shape of the bolt, reducing the installation difficulty of the stationary contact 100. Furthermore, when the shape of the mounting hole 112 matches the bolt, the bolt installation is more stable, reducing the possibility of the stationary contact 100 falling out of the housing 300 due to bolt loosening, and improving the reliability of the contact system.

[0077] In summary, the fixing part 110 allows the stationary contact 100 to be installed inside the molded case circuit breaker. The second bending section 111 makes the fixing part 110, after being connected to the contact part 120, more suitable for the installation environment inside the housing 300, reducing the installation difficulty of the stationary contact 100 when installing it into the housing 300. Furthermore, the bending angle of the second bending section 111 can be selected according to actual usage requirements, making the stationary contact 100 more applicable and further reducing the installation difficulty of the stationary contact 100 when installing it into the housing 300.

[0078] like Figure 2 As shown, to increase the reliability of the contact system, the stationary contact 100 mentioned in this application also includes a contact seat 124, which is disposed on the second straight section 123 and is oriented toward the moving contact 200. A stationary contact is provided on the contact seat 124.

[0079] Setting a stationary contact can increase the contact effect between the moving contact 200 and the stationary contact 100, and also improve the conductivity between them. Setting a stationary contact can increase the reliability of the contact system.

[0080] The contact seat 124 can be located on the second straight section 123 away from the first bent section 122, and the contact seat 124 can be oriented toward the moving contact 200, so that when the stationary contact is installed on the contact seat 124, the stationary contact can make contact with the moving contact.

[0081] The contact seat 124 can be a raised structure or a groove structure, or the contact seat 124 can be a region on the second straight section 123.

[0082] In summary, the contact holder 124 provides installation space for the stationary contact, allowing it to be securely mounted on the stationary contact 100. This reduces the probability of the stationary contact falling off the stationary contact 100, increasing the reliability of the contact system. Furthermore, the contact holder 124 also provides a positioning effect for the stationary contact, reducing installation difficulty and improving installation efficiency.

[0083] When the molded case circuit breaker is in the opening process, the moving contact 200 separates from the stationary contact 100. During this separation, an electric arc is generated between the stationary contact and the moving contact on the moving contact 200. This arc continuously erodes the stationary contact. This may lead to excessive wear on the stationary contact, thereby increasing the operating cost of the contact system.

[0084] To solve the above problems, such as Figures 1 to 3As shown, this application also provides an extension section on the contact seat 124, which extends toward the fixing part 110.

[0085] To reduce the impact of the electric arc generated when the moving contact 200 separates from the stationary contact 100 on the internal components of the molded case circuit breaker, an arc-extinguishing chamber is also provided inside the housing 300. The arc-extinguishing chamber can be disposed on the contact portion 120. The opening of the arc-extinguishing chamber faces the moving contact 200, and the side of the arc-extinguishing chamber without an opening is close to the fixed portion 110. The contact seat 124 is located inside the opening of the arc-extinguishing chamber, and the extension of the contact seat 124 extends towards the fixed portion 110, that is, the extension of the contact seat 124 extends towards the interior of the arc-extinguishing chamber.

[0086] Since an arc-initiating plate is usually installed in the arc-extinguishing chamber, the arc generated when the moving contact 200 separates from the stationary contact 100 will transfer into the arc-extinguishing chamber. The extension of the contact seat 124 extends toward the interior of the arc-extinguishing chamber, so that the arc will transfer from the stationary contact to the extension, thereby reducing the time for the arc to erode the stationary contact.

[0087] In summary, an electric arc is generated during the opening process of a molded case circuit breaker. The extension section allows the arc to be transferred from the stationary contact to the extension section, thus reducing the time the arc spends eroding the stationary contact. When the erosion time of the arc on the stationary contact is reduced, the wear on the stationary contact is decreased, eliminating the need for frequent replacements and thereby lowering the operating cost of the contact system.

[0088] Since the stationary contact 100 is often made of a material with good conductivity, the arc may shift towards the contact portion 120 and move closer to the moving contact 200 during the separation of the moving contact 200 and the stationary contact 100. This will cause the arc to gradually move away from the arc-extinguishing chamber, thereby increasing the arc dwell time.

[0089] To reduce the dwell time of the electric arc between the stationary contact 100 and the moving contact 200, this application also provides a stationary cover within the contact system. The stationary cover can be installed over the contact portion 120.

[0090] The stationary cover can be made of insulating material. The stationary cover can be located between the contact portion 120 and the arc-extinguishing chamber, and the arc-extinguishing chamber placed on the stationary cover can limit the position of the stationary cover. The stationary cover can cover the contact portion 120 except for the contact seat 124 and the stationary contact.

[0091] In summary, since the stationary cover is usually made of insulating material, when it is placed over the contact portion 120, the probability of the arc shifting towards the moving contact 200 can be reduced, and the residence time of the arc between the stationary contact 100 and the moving contact 200 can be reduced. This improves the arc extinguishing efficiency of the molded case circuit breaker.

Claims

1. A contact system, characterized by The application relates to a contact system, comprising: a static contact, comprising a fixed part and a contact part connected with each other, wherein the contact part comprises a first flat section, a first bent section and a second flat section connected in sequence, the first bent section is bent towards the fixed part, and the second flat section is located on one side of the first flat section; a dynamic contact, partially arranged on one side of the contact part away from the fixed part, wherein the dynamic contact comprises a dynamic contact rod, and when the dynamic contact and the static contact are in contact, the first flat section is located between the dynamic contact rod and the second flat section.

2. The contact system of claim 1, wherein, The first bent section is U-shaped. One end of the first bent section connected with the second flat section is bent towards one side away from the dynamic contact.

3. The contact system of claim 1, wherein, The first bent section is I-shaped.

4. The contact system of claim 1, wherein, The contact part is provided with a flow guide groove. The flow guide groove penetrates the contact part along the arrangement direction of the first flat section and the second flat section.

5. The contact system of claim 1, wherein, The fixed part comprises a second bent section. The second bent section is bent towards the dynamic contact compared with the contact part. One end of the second bent section connected with the first flat section is away from the first bent section.

6. The contact system of claim 5, wherein, The fixed part is provided with a mounting hole, and the mounting hole is a circular through hole.

7. The contact system of claim 6, wherein, The static contact comprises a contact seat. The contact seat is arranged on the second flat section, and the contact seat is arranged towards the dynamic contact. The contact seat is provided with a static contact point.

8. The contact system of claim 7, wherein, The contact seat is provided with an extension section. The extension section extends towards the fixed part.

9. The contact system of any of claims 1-8, wherein, The application further comprises a static cover. The static cover covers the contact part.

10. A molded case circuit breaker characterized by, The application comprises a shell and the contact system as claimed in any one of claims 1 to 9. The shell is internally provided with a mounting space. The contact system is arranged in the mounting space.

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