Circuit breaker

Abstract

The present invention relates to a circuit breaker comprising: a housing; the static contact is arranged on the shell; the moving contact is pivotally mounted on the shell and has a closed state in which the moving contact is jointed with the static contact and a separated state in which the moving contact is separated from the static contact; the insulating part is movably arranged on the shell and is provided with a first position and a second position; the bias voltage mechanism is telescopically jointed between the insulating part and the moving contact; wherein when the insulating part is located at the first position, the bias mechanism applies a force which is close to the static contact to the moving contact, and when the insulating part is located at the second position, the bias mechanism applies a force which limits the moving contact to be close to the static contact to the moving contact. And wherein the moving contact is repelled from the static contact in response to a predetermined current condition before the insulator moves from the first position to the second position in response to the predetermined current condition.

Description

Technical Field

[0001] The present invention relates to the technical field of switch devices for protection circuits, and in particular to circuit breakers. Background Art

[0002] A circuit breaker is a switch protection device widely used in industrial production and daily life. It can close and open the circuit under normal current conditions, and can open the circuit within a specified time under abnormal current conditions (such as short circuit or overload), thereby effectively protecting other electrical appliances in the circuit.

[0003] Circuit breakers are usually composed of operating mechanisms, contact systems, arc extinguishing systems, etc. As an important part of circuit breakers, the contact system and its breaking control mechanism have always been the focus of research. In order to enable circuit breakers to withstand higher abnormal currents in the circuit, there is a demand in the industry to improve the contact system to improve the breaking capacity of circuit breakers. Summary of the invention

[0004] The present invention aims to provide a circuit breaker which can at least solve some of the above technical problems.

[0005] According to one aspect of the present invention, a circuit breaker is provided, comprising: a housing; a static contact mounted on the housing; a moving contact pivotally mounted on the housing and having a closed state engaged with the static contact and a separated state repelled from the static contact; an insulating member movably mounted on the housing and having a first position and a second position; a biasing mechanism telescopically engaged between the insulating member and the moving contact; wherein when the insulating member is in the first position, the biasing mechanism applies a force to the moving contact to lean against the static contact, and when the insulating member is in the second position, the biasing mechanism applies a force to the moving contact to restrict the moving contact from leaning against the static contact, and wherein before the insulating member moves from the first position to the second position in response to a predetermined current condition, the moving contact is repelled from the static contact in response to the predetermined current condition.

[0006] According to the circuit breaker provided by this scheme, the insulating member and the biasing mechanism cooperate with each other to keep the moving contact in a state of engagement with the static contact in response to the normal current conditions in the circuit, ensuring that the moving contact will not cause problems such as poor contact due to accidental movement. When an abnormal current condition (such as a short circuit) occurs in the circuit, the increase in electrical repulsion will destroy the stable engagement state with the static contact formed by the insulating member and the biasing mechanism exerting force on the moving contact, causing the moving contact to separate from the static contact. The repulsion action of the moving contact precedes the movement of the insulating member and the biasing mechanism under the control of the external operating mechanism, reducing the response time of the circuit breaker and achieving the effect of rapid disconnection before the abnormal current reaches its peak. After the abnormal current value in the circuit continues to increase, the insulating member and the biasing member begin to move, and eventually keep the moving contact in a state of separation from the static contact, eliminating the possibility of the moving contact rebounding and reengaging with the static contact, thereby improving safety.

[0007] In some embodiments, the insulating member is pivotally mounted on the housing, one end of the biasing mechanism is rotatably mounted on the insulating member, and the other end is pivotally connected to the moving contact.

[0008] In some embodiments, the pivot axis of the insulating member coincides with the pivot axis of the moving contact.

[0009] In some embodiments, a compartment is formed inside the insulating member, and the compartment is configured to have a cross-section that gradually tapers in a direction away from the moving contact. One end of the biasing mechanism is rotatably mounted on a side of the compartment with a smaller cross-section, while the other end extends from a side of the compartment with a larger cross-section and is pivotally connected to the moving contact.

[0010] In some embodiments, a side of the compartment with a smaller cross-section is configured with an arc-shaped support surface, and one end of the biasing mechanism is configured with an arc-shaped end surface adapted to be rotatably accommodated in the arc-shaped support surface.

[0011] In some embodiments, the biasing mechanism includes: a first engaging portion pivotally connected to the moving contact; a second engaging portion rotatably mounted on the insulating member; and a biasing member telescopically connected between the first engaging portion and the second engaging portion.

[0012] In some embodiments, the first engaging portion has a first plunger, and the second engaging portion has a second plunger, and the biasing member is configured as a spring sleeved on the first plunger and the second plunger.

[0013] In some embodiments, the second engaging portion has two cantilever arms located on opposite sides of the second plunger, the two cantilever arms extend beyond the second plunger, and the spring is located between the two cantilever arms.

[0014] In some embodiments, a plurality of moving contacts are mounted side by side on the same pivot shaft, wherein at least one moving contact in the middle has a protrusion extending away from the stationary contact.

[0015] In some embodiments, the circuit breaker further includes: a moving bar mounted on the housing; and a flexible connection connected between the static contact and the moving bar.

[0016] Some of the other features and advantages of the present invention will be apparent to those skilled in the art after reading this application, and the other parts will be described in the following specific embodiments in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The embodiments of the present invention are described in detail below with reference to the accompanying drawings, wherein:

[0018] Figure 1 is an exploded schematic diagram of a circuit breaker according to an embodiment of the present invention at an angle;

[0019] Figure 2 is an exploded schematic diagram of a circuit breaker according to an embodiment of the present invention from another angle;

[0020] Figure 3 is a cross-sectional view of the interior of a circuit breaker according to an embodiment of the present invention, wherein a housing is removed;

[0021] Figure 4 is a cross-sectional view of the interior of a circuit breaker according to an embodiment of the present invention, wherein a housing and an insulating member are removed;

[0022] Figure 5A-5C is a schematic diagram of each moving contact in a moving contact group according to an embodiment of the present invention;

[0023] Figure 6 is a schematic diagram of an insulating member according to an embodiment of the present invention;

[0024] Figure 7 is a schematic diagram of a biasing mechanism according to an embodiment of the present invention, wherein the biasing member is removed;

[0025] Figure 8 Schematic diagram of a dynamic displacement according to an embodiment of the present invention.

[0026] Description of reference numerals:

[0027] 1. Circuit breaker; 2. Housing; 21. First half shell; 211. Opening; 22. Second half shell; 221. Bracket; 3. Stationary contact; 31. Stationary contact; 4. Moving contact; 41. Moving contact; 42. Protrusion; 43. Boss; 44. Shaft hole; 45. Engagement groove; 46. Connecting hole; 5. Pivot shaft; 6. Insulator; 61. Through hole; 62. Compartment; 621. Arc-shaped support surface; 63. First boss; 64. Second boss; 65. Inner space; 66. Opening; 67. Side wall; 7. Biasing mechanism; 71. Biasing member; 72. First engaging portion;

[0028] 721, first plunger; 73, pivot shaft; 74, second engaging portion; 741, cantilever arm;

[0029] 742, arc-shaped end face; 743, second plunger; 8, flexible connection; 9, dynamic row; 91, compartment; 92, joint DETAILED DESCRIPTION

[0030] Now, with reference to the accompanying drawings, a schematic scheme of the circuit breaker disclosed in the present invention is described in detail. Although the accompanying drawings are provided to present some embodiments of the present invention, the accompanying drawings do not have to be drawn according to the dimensions of the specific embodiments, and certain features may be enlarged, removed or partially cut away to better illustrate and explain the disclosure of the present invention. Some components in the accompanying drawings may be adjusted in position according to actual needs without affecting the technical effect. The phrase "in the accompanying drawings" or similar terms appearing in the specification do not necessarily refer to all drawings or examples.

[0031] Certain directional terms used to describe the drawings below, such as "inside", "outside", "above", "below" and other directional terms, will be understood to have their normal meanings and refer to those directions involved when the drawings are normally viewed. Unless otherwise specified, the directional terms described in this specification are basically in accordance with the conventional directions understood by those skilled in the art.

[0032] The terms "first", "first", "second", "second" and the like used in the present invention do not indicate any order, quantity or importance, but are used to distinguish one component from other components.

[0033] The contact system of the circuit breaker provided by the present invention has a contact opening and holding function, which can open the moving contact in advance before the abnormal current (such as short-circuit current) reaches the peak value, thereby achieving the purpose of quickly disconnecting the circuit breaker and improving the circuit breaker performance.

[0034] Figure 1 and Figure 2The circuit breaker according to the present invention is shown as an example. As shown in the figure, the circuit breaker 1 includes a housing 2 and a contact system, an arc extinguishing system, etc. contained in the housing 2. The housing 2 is composed of a first half shell 21 and a second half shell 22, wherein the first half shell 21 and the second half shell 22 jointly enclose an internal space of the housing 2. The first half shell 21 is formed with an opening 211 for one terminal of the circuit breaker 1 to pass through, and an orifice for another terminal of the circuit breaker 1 to pass through is formed between the first half shell 21 and the second half shell 22.

[0035] The static contact 3 is fixed in the housing 2, one end of which extends from the opening 211 of the first half shell 21 as a terminal of the circuit breaker 1, and the other end extends in a U-shape in the internal space of the housing 2. A static contact 31 is installed on the side of the U-shaped section of the static contact 3. Of course, those skilled in the art will understand that the specific form of the static contact is not limited to the illustrated embodiment, and a suitable configuration can be selected according to actual needs, such as a flat plate, or replacing the U-shape with a semi-arc shape, a truncated arc shape, etc.

[0036] The moving contact 4 is arranged in the inner space of the housing 2 through a pivot shaft 5 installed on the housing 2 and can rotate around the central axis of the pivot shaft 5. A moving contact 41 is provided on the side of the moving contact 4 facing the stationary contact 3. As the moving contact 4 rotates, the moving contact 41 can approach and engage with the stationary contact 31, or can be separated from the stationary contact 31, thereby realizing the closing and opening of the circuit breaker 1. Figure 4 A plurality of (five in the example shown in the figure) moving contacts 4 are sleeved side by side on the same pivot shaft 5, thereby forming a moving contact group that moves synchronously. FIG. 5A to FIG. 5C Different configurations of movable contacts 4 in a movable contact group are shown.

[0037] Figure 5A The first type of moving contact 4 is shown as being suitable for being arranged at the outermost side of the moving contact group, and is provided with an axial hole 44 for the pivot shaft 5 to pass through. Figure 5B The second type of moving contact 4 is shown as being suitable for being arranged between the outermost moving contact 4 and the middle moving contact 4. In addition to being provided with an axial hole 44 for the pivot shaft 5 to pass through, it is also provided with a protrusion 43 on one side. When the moving contact group is assembled, the protrusion 43 of the second type of moving contact 4 abuts against another adjacent moving contact 4 to prevent the moving contacts 4 from moving along the axial direction of the pivot shaft 5. Figure 5C What is shown is a third type of moving contact 4 suitable for being arranged in the middle. In addition to being provided with an axial hole 44 for the pivot shaft 5 to pass through and a protrusion 43 for preventing axial movement, a protrusion 42 extending away from the static contact is formed at the end where the moving contact 41 is installed. The protrusion 42 extends toward the arc extinguishing structure of the circuit breaker 1, and is used to concentrate the arc to the arc extinguishing structure for rapid arc extinguishing, so as to improve the safety performance of the circuit breaker.

[0038] The end of the moving contact 4 away from the moving contact point 41 is connected with a flexible connection 8. FIG. 5A to FIG. 5C As shown, one end of the flexible connection 8 can be engaged in the engagement groove 45 of the moving contact 4 by any suitable means (such as welding, bolt connection, etc.). The other end of the flexible connection 8 is connected to the moving bar 9, and the moving bar 9 is connected to the joint 92 fixedly mounted to the bracket 221 of the second half shell 22, so that it cannot move relative to the housing 2. The joint 92 extends from the housing 2 as another terminal of the circuit breaker 1. Figure 8 Each moving contact 4 is connected to a flexible connection 8, and the moving row 9 is formed with a plurality of spaced compartments 91 to respectively accommodate the flexible connections 8. The flexible connection 8 can be installed in the corresponding compartment 91 in any suitable manner, for example, by being pressed into the compartment 91 to form a tight fit with the moving row 9.

[0039] The mechanism for controlling the movement of the moving contact 4 includes an insulating member 6 and a biasing mechanism 7. Figure 3 As shown, the insulating member 6 is also sleeved on the pivot shaft 5 and can rotate around the central axis of the pivot shaft 5. In another embodiment not shown, another pivot shaft coaxial with the pivot shaft 5 can be separately provided for the insulating member 6. The rotation of the insulating member 6 can be controlled by another operating mechanism, which can be selected from the existing technology and will not be described in detail here. Figure 6 The insulating member 6 according to the present invention is shown as an example. Figure 3 and Figure 6 As shown, the insulating member 6 is, for example, a plastic member processed in one piece, and an internal space 65 is formed therein for the moving contact 4 and the flexible connection 8 to pass through. The shape and size of the internal space 65 should be designed to avoid interference with the rotation of the moving contact 4 and the movement of the flexible connection 8 due to the rotation of the moving contact 4. For example, based on the fact that there is a sequence of movement of the moving contact 4 and the insulating member 6 during the opening of the circuit breaker (which will be described in detail later), the opening 66 of the internal space of the insulating member 6 that is open to the static contact should have a sufficient size to allow the moving contact 4 inserted therein to rotate within a certain range without interference. The insulating member 6 is respectively formed with a first boss 63 and a second boss 64 at both ends along the axial direction of the pivot shaft 5, wherein at least a portion of the outer peripheral contour of each of the first boss 63 and the second boss 64 is formed in an arc shape, and the second half shell 22 is respectively formed with arc grooves on two opposite inner walls corresponding to the arc contour of the first boss 63 and the arc contour of the second boss 64. The first boss 63 and the second boss 64 are respectively embedded in the corresponding arc grooves. The insulating member 6 is further formed with a through hole 61 for the pivot shaft 5 to pass through.

[0040] A plurality of compartments 62 are arranged side by side inside the insulating member 6 to accommodate the biasing mechanism 7 corresponding to each moving contact 4. It can be seen from the projection along the axial direction of the pivot shaft 5 (refer to Figure 3), the cross-section of each compartment 62 tapers away from the stationary contact 4, one end of the biasing mechanism 7 extends from the side of the compartment 62 with a larger cross-section and is connected to the corresponding moving contact 4, and the other end is arranged on the side of the compartment 62 with a smaller cross-section. Figure 7 A portion of the biasing mechanism 7 according to the present invention is shown as an example.

[0041] like Figure 3 and Figure 7 As shown, the first engaging portion 72 of the biasing mechanism 7 is pivotally connected to the connecting hole 46 (shown in FIG. FIG. 5A to FIG. 5C ), and the second engaging portion 74 of the biasing mechanism 7 is embedded in the side with a smaller cross-section of the corresponding compartment 62 of the insulating member 6, and can swing relative to the compartment. In the illustrated embodiment, the second engaging portion 74 is only inserted into the compartment 62, and is not connected to the compartment 62 by a connecting member such as a bolt. The end of the second engaging portion 74 away from the first engaging portion 72 can serve as the swing center of the biasing mechanism 7. During the swinging process of the biasing mechanism 7, the two side walls 67 of the compartment 62 that are opposite to each other and inclined to form the above-mentioned tapered cross-section limit the swing stroke of the biasing mechanism 7. Reference Figure 7 , the first engaging portion 72 and the second engaging portion 74 of the biasing mechanism 7 can be close to or away from each other, so that the biasing mechanism 7 can be stretched or compressed as a whole. In one embodiment, an arcuate end surface 742 can be formed at the end of the second engaging portion 74 away from the first engaging portion 72, and an arcuate supporting surface 621 can be formed on the side with a smaller cross section of the compartment 62, and the arcuate supporting surface 621 conforms to the arcuate end surface 742. When the biasing mechanism 7 swings in the compartment 62, the arcuate end surface 742 is wrapped by the arcuate supporting surface 721.

[0042] An elastically retractable biasing member 71 is provided between the first engaging portion 72 and the second engaging portion 74. In one embodiment, the biasing member 71 is configured as a spring, and the first engaging portion 72 is formed with a first plunger 721, and the second engaging portion 74 is formed with a second plunger 743, and the first plunger 721 and the second plunger 743 extend toward each other. The spring is sleeved on the first plunger 721 and the second plunger 743. In one embodiment, the size of the first plunger 721 is larger than the size of the second plunger 743. In order to prevent the spring from accidentally deviating, cantilever arms 741 can be provided on opposite sides of the second plunger 743 of smaller size, respectively, and the cantilever arms 741 can extend over the end of the first plunger 721 close to the second plunger 743, and the spring is confined between the two cantilever arms 741.

[0043] The working principle of the circuit breaker 1 of the present invention will be described in detail below with reference to the accompanying drawings.

[0044] refer to Figure 3, under normal current conditions (or referred to as "first preset current conditions", for example, a current less than 30 kiloamperes), the insulating member 6 rotates to the first position under the control of the operating mechanism, in which the biasing mechanism 7 applies pressure to the moving contact 4 toward the stationary contact 3, so that the moving contact 4 abuts against the stationary contact 3. Thus, the circuit breaker 1 is closed. Since under normal current conditions, the electrical repulsion between the moving contact 4 and the stationary contact 3 is not sufficient to overcome the pressure applied to the moving contact 4 by the biasing mechanism 7, the moving contact 4 is always engaged with the stationary contact 3. At this time, the biasing mechanism 7 is at a dead point, and the moving contact 4 will not easily move.

[0045] Once an abnormal current condition (or referred to as a "second preset current condition", for example, a current equal to or greater than 30 kA but less than 70 kA is generated due to a short circuit) occurs in the circuit, the electric repulsion between the moving contact 4 and the stationary contact 3 increases to a level sufficient to overcome the pressure applied to the moving contact 4 by the biasing mechanism 7, and the moving contact 4 is repelled and rotates around the pivot shaft 5 to move away from the stationary contact 3. At this time, the current in the circuit has not yet reached the threshold for the operating mechanism to respond, so the insulating member 6 and the biasing mechanism 7 have not yet taken action, and only the moving contact 4 is firstly ejected to quickly disconnect the circuit.

[0046] As the current in the loop continues to increase, the abnormal current condition (or referred to as the "third preset current condition", such as a current equal to or greater than 70 kA) causes a mechanical response of the operating mechanism, which drives the insulating member 6 to rotate around the pivot shaft 5 (e.g., along the axis of rotation). Figure 3 The biasing mechanism 7 moves accordingly and passes the dead point position until the insulating member 6 rotates to the second position deviating from the first position. At this time, the biasing mechanism 7 applies a pulling force to the moving contact 4 to prevent it from approaching the stationary contact 3. In this way, the moving contact 4 is kept away from the stationary contact 3 and will not rebound and re-engage with the stationary contact 3, thereby preventing potential safety hazards.

[0047] When the abnormal current condition in the circuit is eliminated, the operating mechanism drives the insulating member 6 to reset to the first position in response to the normal current condition reappearing in the circuit, and the biasing mechanism 7 returns to the dead point position again, pressing the moving contact 4 toward the stationary contact 3, and the circuit breaker 1 resumes closing.

[0048] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0049] The above description is only an illustrative embodiment of the present invention and is not intended to limit the scope of the present invention. Any equivalent changes, modifications and combinations made by any person skilled in the art without departing from the concept and principle of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A circuit breaker, characterized in that: include: Housing (2); A stationary contact (3) mounted on the housing (2); A movable contact (4) is pivotally mounted on the housing (2) and has a closed state in which it is engaged with the stationary contact (3) and a separated state in which it is repelled from the stationary contact (3); An insulating member (6) movably mounted on the housing (2) and having a first position and a second position; A biasing mechanism (7) is telescopically engaged between the insulating member (6) and the moving contact (4); When the insulating member (6) is in the first position, the biasing mechanism (7) applies a force to the moving contact (4) toward the stationary contact (3), and when the insulating member (6) is in the second position, the biasing mechanism (7) applies a force to the moving contact (4) to restrict the moving contact (4) from leaning toward the stationary contact (3), and before the insulating member (6) moves from the first position to the second position in response to a predetermined current condition, the moving contact (4) is repelled from the stationary contact (3) in response to the predetermined current condition.

2. The circuit breaker according to claim 1, characterized in that: The insulating member (6) is pivotally mounted on the housing (2); one end of the biasing mechanism (7) is rotatably mounted on the insulating member (6), and the other end is pivotally connected to the moving contact (4).

3. The circuit breaker according to claim 2, characterized in that: The pivot axis of the insulating member (6) coincides with the pivot axis of the moving contact (4).

4. The circuit breaker according to any one of claims 1 to 3, characterized in that: A compartment (62) is formed inside the insulating member (6), and the compartment (62) is configured such that its cross section gradually decreases in a direction away from the moving contact (4). One end of the biasing mechanism (7) is rotatably mounted on a side of the compartment (62) with a smaller cross section, while the other end extends from a side of the compartment (62) with a larger cross section and is pivotally connected to the moving contact (4).

5. The circuit breaker according to claim 4, characterized in that: A side of the compartment (62) with a smaller cross section is configured to form an arc-shaped support surface (621), and one end of the biasing mechanism (7) is configured to form an arc-shaped end surface (742) suitable for being rotatably accommodated in the arc-shaped support surface (621).

6. The circuit breaker according to any one of claims 1 to 3, characterized in that: The biasing mechanism (7) comprises: A first engaging portion (72) pivotally connected to the moving contact (4); A second engaging portion (74) rotatably mounted on the insulating member (6); The biasing member (71) is telescopically connected between the first engaging portion (72) and the second engaging portion (74).

7. The circuit breaker according to claim 6, characterized in that: The first engaging portion (72) has a first plunger (721), and the second engaging portion (74) has a second plunger (743), and the biasing member (71) is configured as a spring sleeved on the first plunger (721) and the second plunger (743).

8. The circuit breaker according to claim 7, characterized in that: The second engaging portion (74) has two cantilever arms (741) located on opposite sides of the second plunger (743), the two cantilever arms (741) extending beyond the second plunger (743), and the spring is located between the two cantilever arms (741).

9. The circuit breaker according to any one of claims 1 to 3, characterized in that: A plurality of moving contacts (4) are mounted side by side on the same pivot shaft (5), wherein at least one moving contact (4) located in the middle has a protrusion (42) extending away from the stationary contact (3).

10. The circuit breaker according to any one of claims 1 to 3, characterized in that: The circuit breaker further comprises: A dynamic row (9) mounted on the housing (2); A soft connection (8) is connected between the stationary contact (3) and the moving row (9).

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