Circuit breaker and moving contact mounting structure

Abstract

The invention provides a novel repulsion drop delay scheme which is different from a conventional moving contact anti-drop mode and an automatic rebound drop mode, and a damping structure is added in the repulsion drop action process of the moving contact, so that the action time of the moving contact from repulsion to drop is prolonged, and before the moving contact drops to be in contact with a static contact, the static contact is prevented from falling off. The main switch module completes the short circuit disconnection action, so that the automatic falling can be realized while the secondary short circuit does not occur, and an extra pushing mechanism does not need to be added.

Description

Technical Field

[0001] The invention relates to a circuit breaker and a moving contact installation structure. Background Art

[0002] A molded case circuit breaker (MCCB) is a protective device used in low-voltage power distribution systems. It offers multiple protection features, including overload, short circuit, and leakage protection. It is widely used in industrial, construction, and household circuits. Its core feature is its high-strength plastic casing enclosing the internal components, providing both insulation and protection.

[0003] Currently, there are many types of molded case circuit breakers on the market. When normally connected, a spring exerts elastic pressure on the moving contact, allowing it to contact the static contact under the spring pressure. In addition, according to product design requirements, the moving contact can only be repelled from the static contact when the short-circuit current reaches, for example, 8 times or more of its rated current (the multiple is determined by the product design requirements). If the short-circuit current is less than 8 times the rated current, the moving contact cannot be repelled, which requires the spring to exert a certain force on the moving contact to keep it in contact with the static contact.

[0004] That is to say, when a short circuit occurs and the short-circuit current reaches, for example, 8 times or more of its rated current, a very large repulsive force will be generated between the moving contact and the static contact, which will repel the moving contact from the static contact, thereby separating the moving contact from the static contact; and because the elastic pressure of the spring is applied to the moving contact, the moving contact that is repelled by the spring will rebound and fall again and come into contact with the static contact, which may cause a secondary short circuit.

[0005] In the past, in order to prevent the repelled moving contact from falling rapidly under the action of the spring and contacting the static contact to cause a secondary short circuit, the idea of ​​repelling stop was proposed, that is, after the moving contact is repelled, it is fixed in a stop position to prevent it from falling. This solution is also called the moving contact anti-fall method. Summary of the Invention

[0006] However, adopting a method to prevent the moving contact from dropping out introduces a new problem. Specifically, because the moving contact is fixed in place after opening, an external force is required to push the moving contact out of its fixed position when the main switch module is closed again. This requires the addition of another pushing mechanism within the circuit breaker, complicating the circuit breaker structure and increasing costs.

[0007] If the moving contact anti-drop method is not adopted, the moving contact will rebound quickly (automatically rebound and fall) under the action of the spring after being repelled. It is possible that the moving contact will rebound and fall into contact with the static contact before the short-circuit disconnection action of the main switch module is completed, thereby causing a secondary short circuit.

[0008] The present invention is completed in view of the above situation, and its purpose is to provide a new type of repulsion delayed falling scheme that is different from the previous moving contact anti-falling method and automatic rebound falling method. By adding a damping structure during the repulsion and falling action of the moving contact, the action time of the moving contact from repulsion to falling is extended, so that before the moving contact falls and contacts with the static contact, the main switch module has completed the short-circuit disconnection action, so that secondary short circuit will not occur and automatic falling can be achieved without adding unnecessary pushing mechanism.

[0009] Technical solutions to technical problems

[0010] In order to solve the above problem, the circuit breaker involved in the first aspect of the present invention includes a moving contact assembly, a static contact assembly, a spring, and a main switch module for controlling the moving contact assembly.

[0011] When normally connected, the moving contact assembly is pressed against the static contact assembly by the elastic force of the spring.

[0012] When a short circuit occurs, the time from when the moving contact assembly is pushed away from the static contact assembly to when the moving contact assembly falls back to the static contact assembly is greater than the time required for the main switch module to complete the disconnection action.

[0013] Furthermore, a damping structure is included.

[0014] During the movement of the moving contact assembly from being pushed away from the static contact assembly to falling back to the static contact assembly, the damping structure acts on the moving contact assembly to delay its movement time.

[0015] Furthermore, the action process of the movable contact assembly from the moment the static contact assembly is pushed away to the moment the movable contact assembly falls back to the static contact assembly includes:

[0016] The first stage is when the moving contact assembly is moved away from the static contact assembly until the moving contact assembly is located in the middle position;

[0017] a second stage, in which the movable contact assembly moves from the intermediate position to the final opening position;

[0018] a third stage, in which the movable contact assembly falls from the repelling end position to the intermediate position under the elastic force of the spring;

[0019] In the fourth stage, under the elastic force of the spring, the moving contact assembly falls from the middle position to contact with the static contact assembly.

[0020] Wherein, in the second stage and the third stage, the damping structure acts on the moving contact assembly to delay its action time.

[0021] Furthermore, a damping structure is provided on the arc surface of the moving contact assembly that contacts the connecting shaft of the spring.

[0022] Furthermore, the arc surface of the moving contact assembly in contact with the connecting shaft of the spring includes a front segment surface with a friction coefficient less than or equal to a first predetermined value and a rear segment surface with a friction coefficient greater than or equal to a second predetermined value.

[0023] Furthermore, a damping structure is provided on the spring.

[0024] Furthermore, the spring includes a front section having an elastic coefficient less than or equal to a first threshold value and a rear section having an elastic coefficient greater than or equal to a second threshold value.

[0025] Furthermore, the spring has a function of delayed rebound.

[0026] Furthermore, the process from the moving contact assembly being pushed away from the static contact assembly to the moving contact assembly falling back to the static contact assembly includes:

[0027] The first stage is when the moving contact assembly is moved away from the static contact assembly until the moving contact assembly is located in the middle position;

[0028] a second stage, in which the movable contact assembly moves from the intermediate position to the final opening position;

[0029] a third stage, in which the movable contact assembly falls from the repelling end position to the intermediate position under the elastic force of the spring;

[0030] In the fourth stage, under the elastic force of the spring, the moving contact assembly falls from the middle position to contact with the static contact assembly.

[0031] The total time from the first stage to the fourth stage is greater than the time required for the main switch module to complete the disconnection action.

[0032] The damping force of the moving contact assembly during the first and fourth stages of movement is smaller than the damping force of the moving contact assembly during the second and third stages of movement.

[0033] Furthermore, the time from the start of the moving contact assembly being pushed away from the static contact assembly to the time the moving contact assembly falls back to the static contact assembly is 10 to 20 ms.

[0034] The second aspect of the present invention relates to a moving contact mounting structure, comprising a moving contact assembly and a spring.

[0035] A damping structure is provided on the arc surface of the moving contact assembly that contacts the connecting shaft of the spring, so that when a short circuit occurs, the time from the start of the moving contact assembly being repelled from the static contact assembly to the time the moving contact assembly falls back to the static contact assembly is greater than the time required for the main switch module to complete the disconnection action.

[0036] Furthermore, the arc surface of the moving contact assembly in contact with the connecting shaft of the spring includes a front segment surface with a friction coefficient less than or equal to a first predetermined value and a rear segment surface with a friction coefficient greater than or equal to a second predetermined value.

[0037] Effects of the Invention

[0038] According to the circuit breaker of the present invention, a damping structure is added during the repelling and falling action of the moving contact to prolong the action time from the repelling to the falling of the moving contact, so that before the moving contact falls and contacts the static contact, the main switch module has completed the short-circuit disconnection action, thereby preventing a secondary short circuit and achieving automatic falling without the need to add an unnecessary pushing mechanism.

[0039] In addition, according to the circuit breaker of the present invention, by making the damping force of the moving contact assembly from the start of repulsion to the predetermined intermediate position smaller, the moving contact can be quickly separated from the static contact to a certain distance at the beginning of repulsion, thereby avoiding the generation of arc. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 Schematic diagram showing a structural example of a movable contact assembly and a stationary contact assembly in a circuit breaker according to an embodiment of the present invention.

[0041] Figure 2A It is a schematic diagram showing a specific structural example of a movable contact assembly in a circuit breaker according to an embodiment of the present invention.

[0042] Figure 2B It is a partially enlarged schematic diagram showing a specific structural example of the arc surface of the movable contact assembly in the circuit breaker according to the embodiment of the present invention, which contacts the connecting shaft of the spring.

[0043] Figure 3A 、 Figure 3B 、 Figure 3C This is a schematic diagram illustrating an example of a process in which a movable contact assembly in a circuit breaker according to an embodiment of the present invention moves from the start of opening to a predetermined intermediate position and reaches an opening end position. DETAILED DESCRIPTION

[0044] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0045] For ease of description, spatially relative terms, such as "below," "beneath," "below," "above," and "upper," may be used herein to describe the relationship of one element or feature relative to another element or feature as shown in the figures. It should be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation shown in the figures. For example, if the device in the figures is turned over, an element described as "below" or "beneath" another element or feature would then be oriented "above" the other element or feature.

[0046] Unless otherwise defined, the terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention belongs. Terms should be understood to have meanings consistent with their meanings in the context of the relevant technology and should not be understood in an idealized or overly formal sense unless explicitly defined herein.

[0047] <Circuit Breaker>

[0048] Hereinafter, a circuit breaker according to an embodiment of the present invention will be described in detail with reference to the drawings.

[0049] Figure 1 Schematic diagram showing a structural example of a movable contact assembly and a stationary contact assembly in a circuit breaker according to an embodiment of the present invention. Figure 2A It is a schematic diagram showing a specific structural example of a movable contact assembly in a circuit breaker according to an embodiment of the present invention.

[0050] like Figure 1 As shown, the circuit breaker involved in the embodiment of the present invention includes a moving contact assembly 101, a static contact assembly 102, a spring (not shown in the figure), and a main switch module (not shown in the figure) for controlling the moving contact assembly 101. In addition, as an example, the circuit breaker may include three independent moving contact assemblies 101 and three corresponding static contact assemblies 102, but the present invention is not limited to this. In addition, as shown in FIG. Figure 2A As shown, the movable contact assembly 101 is composed of a movable contact piece 101a and a contact support 101b. In addition, the movable contact assembly 101 and the spring constitute a movable contact mounting structure.

[0051] During normal connection, Figure 1 As shown, the moving contact assembly 101 is pressed against the stationary contact assembly 102 by the elastic force of the spring.

[0052] When a short circuit occurs, for example, when the short circuit current reaches more than 8 times the rated current, Figure 3A 、 Figure 3B 、 Figure 3C As shown, the moving contact assembly 101 will be repelled from the static contact assembly 102, and the moving contact assembly 101 will rotate around the central axis 1002 of the contact support 101b in the housing (clockwise rotation in the figure), thereby separating the moving contact assembly 101 from the static contact assembly 102 to achieve switch opening.

[0053] In the present invention, a damping structure is added during the repelling and falling action of the moving contact assembly 101 to extend the action time from repelling to falling of the moving contact assembly 101, so that the time from the start of the repelling of the moving contact assembly 101 by the static contact assembly 102 to the time when the moving contact assembly 101 falls back to the static contact assembly 102 is greater than the time required for the main switch module to complete the disconnection action.

[0054] As an example, the time required for the main switch module to respond to a short circuit and trigger the completion of the disconnection action is 8ms. At this time, by adding a damping structure during the repulsion and falling action of the moving contact assembly 101, the time from the start of the repulsion of the moving contact assembly 101 from the static contact assembly 102 to the falling back of the moving contact assembly 101 to the static contact assembly 102 is 10-20ms, but the present invention is not limited to this.

[0055] Methods for adding a damping structure during the repelling and falling action of the moving contact assembly 101 include, for example: providing a damping structure on the arc surface 1001 of the moving contact assembly that contacts the connecting shaft 2001 of the spring; providing a damping structure on the spring; using a spring with a delayed rebound function, etc.

[0056] Next, use Figure 2B 、 Figure 3A 、 Figure 3B 、 Figure 3C , the manner of providing the damping structure on the arc surface 1001 of the moving contact assembly 101 that contacts the connecting shaft 2001 of the spring is described in detail.

[0057] Figure 2B It is a partially enlarged schematic diagram showing a specific structural example of the arc surface of the movable contact assembly in the circuit breaker according to the embodiment of the present invention, which contacts the connecting shaft of the spring. Figure 3A 、 Figure 3B 、 Figure 3C This is a schematic diagram illustrating an example of a process in which a movable contact assembly in a circuit breaker according to an embodiment of the present invention moves from the start of opening to a predetermined intermediate position and reaches an opening end position.

[0058] like Figure 2BAs shown, as an example, the arc surface 1001 of the moving contact assembly 101 in contact with the connecting shaft 2001 of the spring includes a front segment surface 1001a with a friction coefficient less than or equal to a first predetermined value and a rear segment surface 1001b with a friction coefficient greater than or equal to a second predetermined value.

[0059] In addition, the process from the moving contact assembly 101 being pushed away from the stationary contact assembly 102 to the moving contact assembly 101 falling back to the stationary contact assembly 102 can be decomposed into:

[0060] Phase I Figures 3A to 3B ), in the first stage, the moving contact assembly 101 starts from the static contact assembly 102 being repelled and ends when the moving contact assembly 101 is in the middle position;

[0061] Phase II Figures 3B to 3C ), in the second stage, the moving contact assembly 101 reaches the final opening position from the middle position;

[0062] Phase III Figure 3C to Figure 3B ), in the third stage, under the elastic force of the spring, the moving contact assembly 101 falls from the repelling end position to the middle position;

[0063] Phase IV Figure 3B to Figure 3A ), in the fourth stage, under the elastic force of the spring, the moving contact assembly 101 falls from the middle position to contact with the static contact assembly 102.

[0064] In addition, preferably, in the second stage and the third stage, the damping structure acts on the moving contact assembly 101 to delay its action time.

[0065] Among them, in the first stage from the start of the repulsion of the moving contact assembly 101 to the predetermined middle position, the front section surface 1001a of the moving contact assembly 101 with a smaller friction coefficient contacts the connecting shaft 2001 of the spring and applies force to the connecting shaft 2001 (that is, no damping structure is set in the first stage), thereby completing the action of the first stage quickly and neatly, quickly forming a sufficiently safe distance between the moving contact assembly 1001 and the static contact assembly 1002, and avoiding the generation of arcs to the greatest extent.

[0066] In addition, the final position of the opening refers to the final position (e.g., the position at which the moving contact assembly 101 moves outward from the middle position away from the static contact assembly 102) of the moving contact assembly 101. Figure 3C As shown in FIG. 1 ). In the second stage from the middle position to the final repulsion position of the moving contact assembly 101, the rear surface 1001b of the moving contact assembly 101 with a larger friction coefficient contacts the connecting shaft 2001 of the spring and applies force to the connecting shaft 2001 (i.e., a damping structure can be provided in the second stage to delay the action time). Figure 3B 、 Figure 3C shown.

[0067] In addition, falling refers to the process in which the movable contact assembly 101 rebounds from the final repulsion position to the stationary contact assembly 102 under the action of the spring. This process is also divided into two stages (i.e., the third stage and the fourth stage). In the third stage, under the elastic force of the spring, the movable contact assembly 101 falls from the final repulsion position to the intermediate position; in the fourth stage, under the elastic force of the spring, the movable contact assembly 101 falls from the intermediate position until it contacts the stationary contact assembly 102.

[0068] In addition, the sum of the time required for the first, second, third, and fourth stages must be greater than the time required for the main switch module to complete the disconnection action. As an example, the time required for the main switch module to respond to a short circuit and trigger the completion of the disconnection action is 8ms, and the sum of the time required for the first, second, third, and fourth stages is 10ms. However, the present invention is not limited to this. The sum of the time required for the first, second, third, and fourth stages can also be greater than 10ms and less than or equal to 20ms. In addition, preferably, the damping force of the moving contact assembly 101 during the first and fourth stages is less than the damping force of the moving contact assembly 101 during the second and third stages.

[0069] Therefore, according to the circuit breaker of the present invention, a damping structure is added during the repelling and falling action of the moving contact to prolong the action time from the repelling to the falling of the moving contact, so that before the moving contact falls and contacts the static contact, the main switch module has completed the short-circuit disconnection action, thereby preventing a secondary short circuit and achieving automatic falling without the need to add an unnecessary pushing mechanism.

[0070] In addition, according to the circuit breaker of the present invention, by making the damping force of the moving contact assembly from the start of repulsion to the predetermined intermediate position smaller, the moving contact can be quickly separated from the static contact to a certain distance at the beginning of repulsion, thereby avoiding the generation of arc.

[0071] Furthermore, in the present invention, in addition to providing a damping structure on the arc surface 1001 of the moving contact assembly that contacts the connecting shaft 2001 of the spring (the first method), a damping structure may also be provided on the spring (the second method).

[0072] Specifically, as an example, the spring may include a front section with a smaller elastic coefficient (e.g., less than or equal to a first threshold value) and a rear section with a larger elastic coefficient (e.g., greater than or equal to a second threshold value). Thus, the damping force of the moving contact assembly 101 from the start of the repulsion to the middle position in the first stage (and the fourth stage when the moving contact assembly 101 falls from the middle position to the contact with the static contact assembly 102) is smaller, and the damping force of the moving contact assembly 101 from the middle position to the end of the repulsion (and the third stage when the moving contact assembly 101 falls from the end of the repulsion to the middle position) is larger. Thus, similar to the first method described above, the technical effects of "automatic falling without the occurrence of secondary short circuits without the need to add redundant pushing mechanisms" and "quickly separating the moving contact from the static contact to a certain distance at the beginning of the repulsion, thereby avoiding the generation of arcs" can also be achieved.

[0073] Furthermore, in addition to the first method of providing a damping structure on the arc surface 1001 of the movable contact assembly that contacts the spring connecting shaft 2001, and the second method of providing a damping structure on the spring, the present invention also employs a third method of using a spring with a delayed rebound function. This, similar to the first and second methods, also achieves the technical effects of "preventing secondary short circuits while achieving automatic drop without the need for additional propulsion mechanisms" and "quickly separating the movable contact from the stationary contact to a certain distance at the initial stage of repulsion, thereby preventing the generation of arcs."

[0074] In addition, in the present invention, the above-mentioned first method, second method, and third method can also be flexibly combined to achieve the technical effects of "automatic falling can be achieved without the occurrence of secondary short circuit, without the need to add unnecessary pushing mechanisms" and "the moving contact can be quickly separated from the static contact to create a certain distance at the beginning of the repulsion, thereby avoiding the generation of electric arcs."

[0075] It should be understood that the above description is illustrative and not restrictive. For example, the above embodiments (and / or their aspects) can be used in combination with each other. In addition, without departing from the scope of the present invention, many modifications can be made to adapt specific conditions or materials to the teachings of the various embodiments of the present invention. Although the size and type of materials described herein are used to define the parameters of the various embodiments of the present invention, the various embodiments are not meant to be restrictive, but rather exemplary embodiments. Upon reading the above description, many other embodiments will be apparent to those skilled in the art. Therefore, the scope of the various embodiments of the present invention should be determined with reference to the appended claims, and the full range of equivalent forms claimed for protection by these claims.

[0076] Industrial applicability

[0077] The circuit breaker and movable contact mounting structure of the present invention can be widely used in industrial, architectural and household circuits.

Claims

1. A circuit breaker, characterized in that: It includes a moving contact assembly, a static contact assembly, a spring, and a main switch module for controlling the moving contact assembly. When normally connected, the moving contact assembly is pressed against the static contact assembly by the elastic force of the spring. When a short circuit occurs, the time from when the moving contact assembly is pushed away from the static contact assembly to when the moving contact assembly falls back to the static contact assembly is greater than the time required for the main switch module to complete the disconnection action.

2. The circuit breaker according to claim 1, wherein: Also includes a damping structure, During the movement of the moving contact assembly from being pushed away from the static contact assembly to falling back to the static contact assembly, the damping structure acts on the moving contact assembly to delay its movement time.

3. The circuit breaker according to claim 2, characterized in that The action process of the moving contact assembly from the static contact assembly being pushed away to the moving contact assembly falling back to the static contact assembly includes: The first stage is when the moving contact assembly is moved away from the static contact assembly until the moving contact assembly is located in the middle position; a second stage, in which the movable contact assembly moves from the intermediate position to the final opening position; a third stage, in which the movable contact assembly falls from the repelling end position to the intermediate position under the elastic force of the spring; In the fourth stage, under the elastic force of the spring, the moving contact assembly falls from the middle position to contact with the static contact assembly. Wherein, in the second stage and the third stage, the damping structure acts on the moving contact assembly to delay its action time.

4. The circuit breaker according to claim 1 or 2, characterized in that: A damping structure is provided on the arc surface of the moving contact assembly that contacts the connecting shaft of the spring.

5. The circuit breaker according to claim 4, characterized in that The arc surface of the moving contact assembly in contact with the connecting shaft of the spring includes a front segment surface with a friction coefficient less than or equal to a first predetermined value and a rear segment surface with a friction coefficient greater than or equal to a second predetermined value.

6. The circuit breaker according to claim 1 or 2, characterized in that: The spring is provided with a damping structure.

7. The circuit breaker according to claim 6, characterized in that The spring includes a front section with an elastic coefficient less than or equal to a first threshold value and a rear section with an elastic coefficient greater than or equal to a second threshold value.

8. The circuit breaker according to claim 1 or 2, characterized in that: The spring has a function of delaying rebound.

9. The circuit breaker according to claim 2, wherein: The process of the movable contact assembly from the static contact assembly being pushed away to the static contact assembly falling back to the movable contact assembly includes: The first stage is when the moving contact assembly is moved away from the static contact assembly until the moving contact assembly is located in the middle position; a second stage, in which the movable contact assembly moves from the intermediate position to the final opening position; a third stage, in which the movable contact assembly falls from the repelling end position to the intermediate position under the elastic force of the spring; In the fourth stage, under the elastic force of the spring, the moving contact assembly falls from the middle position to contact with the static contact assembly. The total time from the first stage to the fourth stage is greater than the time required for the main switch module to complete the disconnection action. The damping force of the moving contact assembly during the first and fourth stages of movement is smaller than the damping force of the moving contact assembly during the second and third stages of movement.

10. The circuit breaker according to claim 1 or 2, characterized in that: The time from when the movable contact assembly is pushed away from the static contact assembly to when the movable contact assembly falls back to the static contact assembly is 10 to 20 ms.

11. A moving contact mounting structure, characterized in that: Including moving contact assembly and spring, A damping structure is provided on the arc surface of the moving contact assembly that contacts the connecting shaft of the spring, so that when a short circuit occurs, the time from the start of the moving contact assembly being repelled from the static contact assembly to the time the moving contact assembly falls back to the static contact assembly is greater than the time required for the main switch module to complete the disconnection action.

12. The movable contact mounting structure according to claim 11, characterized in that: The arc surface of the moving contact assembly in contact with the connecting shaft of the spring includes a front segment surface with a friction coefficient less than or equal to a first predetermined value and a rear segment surface with a friction coefficient greater than or equal to a second predetermined value.

Images