An operating mechanism for a low voltage circuit breaker

Abstract

An operating mechanism for a low-voltage circuit breaker belongs to the technical field of low-voltage electrical appliances. It includes a trip lever, a lock lever, an upper connecting rod, a lower connecting rod, a handle lever, a connecting shaft, a side plate, a main spring, a rotating shaft and a common pivot shaft. A re-locking pusher is provided on the handle lever; the trip lever is provided with a first hinged portion hinged to the upper connecting rod and a second hinged portion hinged to the side plate, and a limiter is provided on the upper connecting rod so that the trip lever and the upper connecting rod maintain a fixed relative position relationship; when the upper connecting rod and the lower connecting rod are in the position of the circuit breaker tripping state, and the handle lever is in the closing position, the center point of the first hinged portion is on the side of the main spring facing the lock lever; at the same time, the re-locking pusher is on the side of the line connecting the center point of the second hinged portion and the center point of the first hinged portion away from the lock lever. Advantages: It can meet the requirements of miniaturized design of the circuit breaker while maintaining the overall design of the four-bar linkage in the completion of the tripping action.

Description

Technical Field

[0001] The invention belongs to the technical field of low-voltage electrical appliances, and in particular relates to an operating mechanism of a low-voltage circuit breaker. Background Art

[0002] The main functional components of the circuit breaker include a contact system, an operating mechanism, a tripping device, a handle and a rotating shaft. When the tripping device of the circuit breaker detects an abnormal current in the circuit, the operating mechanism is actuated to unlock the tripping action, and the moving and static contacts in the contact system are separated from each other to disconnect the fault current in the circuit, thereby achieving the purpose of protecting the circuit; when the circuit fault is eliminated, the circuit breaker must first be re-triggered to reset the operating mechanism, and then the closing operation is performed to complete the reconnection of the circuit. Conventional low-voltage circuit breakers have various operating mechanisms, generally including a handle lever, a main spring, a tripping buckle, a lock buckle and a rotating shaft. The operating mechanism uses force transmission between the connecting rods to achieve the closing and separation of the moving and static contacts, and the purpose of tripping is achieved by converting the four-link and five-link of the operating mechanism. Specifically, during the closing and opening operation, one of the connecting rods is locked to convert the five-link structure into a four-link structure, so that only one degree of freedom exists to complete the closing and opening actions, and during the tripping operation, this connecting rod is unlocked to restore it to a five-link structure to open the rotating shaft. However, this conventional structure has uncertainties in two degrees of freedom in the design of the five-link, which may cause the link to self-lock during the tripping operation. At this time, the mechanism will enter an abnormal locking position and indicate an erroneous state, which may cause danger and even affect the life safety of the operating and maintenance personnel in serious cases.

[0003] To solve the above problem, one degree of freedom can be temporarily restricted so that the five-link during the tripping operation can still maintain the form of a four-link during the action process, thereby avoiding the occurrence of self-locking during the tripping action, and reducing the two limit conditions required for the five-link to constrain its two degrees of freedom in the final stable position to one, simplifying the structure and improving the reliability of the entire mechanism structure. However, this improvement plan still has defects: the action range of the trip button changes significantly, so that after the tripping action is completed, when the re-buttoning operation is performed, the area where the push shaft is set needs to be moved significantly outward, thereby increasing the space width occupied by the mechanism, which is greatly limited in miniaturized products.

[0004] In view of the above-mentioned prior art, the applicant has made a useful design, and the technical solution to be introduced below is produced in this context. Summary of the invention

[0005] The object of the present invention is to provide an operating mechanism for a low voltage circuit breaker, which has high overall structural stability and is conducive to realizing a miniaturized design of the product.

[0006] The object of the present invention is achieved in this way. An operating mechanism of a low-voltage circuit breaker includes a trip lever, a lock lever, an upper connecting rod, a lower connecting rod, a handle lever, a connecting shaft, a side plate, a main spring, a rotating shaft and a common pivot shaft. The trip lever, the lock lever and the handle lever are rotatably arranged on the side plate. The handle lever is provided with a re-locking pusher, and the re-locking pusher drives the trip lever to rotate so that it contacts and locks with the lock lever; the upper connecting rod and the lower connecting rod are pivotally connected by the connecting shaft; one end of the main spring is hung on the handle lever, and the other end is hung on the connecting shaft; the rotating shaft is connected to the lower connecting rod by a pivot shaft, and is realized by the movement of the lower connecting rod The tripping lever is provided with a first hinged part hinged with the upper connecting rod and a second hinged part hinged with the side plate, and the second hinged part constitutes the rotation center of the tripping lever, and is characterized in that: a limit member is provided on the upper connecting rod, and the limit member contacts and cooperates with the tripping lever during the circuit breaker tripping process, so that the tripping lever and the upper connecting rod maintain a fixed relative position relationship; when the upper connecting rod and the lower connecting rod are in the position of the circuit breaker tripping state, and the handle lever is in the closing position, the center of the first hinged part is located on the side of the main spring facing the locking lever; at the same time, the re-locking pusher is located on the side of the line connecting the center point of the second hinged part and the center point of the first hinged part away from the locking lever.

[0007] In a specific embodiment of the present invention, the re-fastening pusher is a round shaft, a semi-circular shaft or a round boss.

[0008] In another specific embodiment of the present invention, the limiting member is a round shaft, a semicircular shaft or a round boss.

[0009] In yet another specific embodiment of the present invention, the first hinge portion is a hole or a boss.

[0010] In yet another specific embodiment of the present invention, the second hinged portion is a hole or a boss.

[0011] Due to the adoption of the above structure, the present invention has the following beneficial effects compared with the prior art: due to the additional setting of the limiter, the torque direction of the upper connecting rod during the tripping action can be ensured, so that the tripping lever and the upper connecting rod are always in contact and maintain a fixed relative position relationship throughout the whole process, and the overall stable state can be maintained by only setting a constrained limiter on the rotating shaft; at the same time, the stable contact between the tripping lever and the upper connecting rod can ensure that the rotating shaft is always kept in the open position, even if the handle lever is subjected to force from the main spring and reaches the tripping stable state in which the re-snapping pusher contacts the tripping lever, it will not affect the upper connecting rod and the rotating shaft, thereby avoiding the self-locking of the connecting rod; the re-snapping pusher is arranged on the left side of the tripping lever, and the design of maintaining the four-bar mechanism as a whole during the tripping action is completed without increasing the width, which can meet the requirements of miniaturized design of the circuit breaker. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the operating mechanism of the circuit breaker of the present invention when it is in the closing position.

[0013] Figure 2 It is a schematic diagram of the operating mechanism of the circuit breaker of the present invention when it is in the open position.

[0014] Figure 3 It is a schematic diagram of the operating mechanism connecting rod of the circuit breaker of the present invention reaching the tripping position.

[0015] Figure 4 It is a schematic diagram of the operating mechanism of the circuit breaker of the present invention when it is in the tripping position.

[0016] Figure 5 It is a schematic diagram of the installation position of the re-fastening mechanism in the prior art.

[0017] Figure 6 It is a schematic diagram of the installation position of the re-fastening pusher described in the present invention.

[0018] Figure 7 The figure is an exploded schematic diagram of the circuit breaker operating mechanism of the present invention.

[0019] In the figure: 1. trip lever, 11. first hinge part, 12. second hinge part; 2. lock lever; 3. upper connecting rod, 31. limit member; 4. lower connecting rod; 5. handle lever, 51. re-locking push member, 52. re-locking shaft; 6. connecting shaft; 7. side plate; 8. main spring; 9. rotating shaft; 10. common pivot shaft. DETAILED DESCRIPTION

[0020] The specific implementation modes of the present invention are described in detail below in conjunction with the accompanying drawings, but the description of the embodiments is not a limitation of the technical solution. Any changes in form rather than substance based on the concept of the present invention should be regarded as the protection scope of the present invention.

[0021] In the following description, all concepts related to directionality (or orientation) such as up, down, left, right, front and back are referring to the position state of the figure being described, and are intended to facilitate public understanding. Therefore, they should not be understood as special limitations on the technical solution provided by the present invention.

[0022] The present invention relates to an operating mechanism of a low-voltage circuit breaker, wherein the circuit breaker comprises an operating mechanism, a handle and a contact system, wherein the contact system comprises a moving contact and a static contact. When the circuit breaker is switched on and off, the handle drives the operating mechanism to move, and the operating mechanism drives the moving contact to contact or separate with the static contact through a rotating shaft, thus realizing the movement of the contact system.

[0023] Please refer to Figure 1 Combined with Figure 7 The present invention relates to an operating mechanism of a low-voltage circuit breaker, comprising a tripping lever 1, a locking lever 2, an upper connecting rod 3, a lower connecting rod 4, a handle lever 5, a connecting shaft 6, a side plate 7, a main spring 8, a rotating shaft 9 and a common pivot shaft 10. The tripping lever 1, the locking lever 2 and the handle lever 5 are rotatably arranged on the side plate 7, and a re-locking pusher 51 is arranged on the handle lever 5, and the re-locking pusher 51 drives the tripping lever 1 to rotate so that it contacts and locks with the locking lever 2. The upper connecting rod 3 and the lower connecting rod 4 are pivotally connected through the connecting shaft 6, and a limiting member 31 is arranged on the upper connecting rod 3. The limiting member 31 contacts and cooperates with the tripping lever 1 during the circuit breaker tripping process, so that the tripping lever 1 and the upper connecting rod 3 maintain a fixed relative position relationship. One end of the main spring 8 is hung on the handle lever 5, and the other end is hung on the connecting shaft 6. The rotating shaft 9 is connected to the lower connecting rod 4 through a pivot shaft 10, and is rotated by the movement of the lower connecting rod 4. The tripping lever 1 is provided with a first hinged portion 11 hinged to the upper connecting rod 3 and a second hinged portion 12 hinged to the side plate 7, and the second hinged portion 12 constitutes the rotation center of the tripping lever 1. When the upper connecting rod 3 and the lower connecting rod 4 are in the position of the circuit breaker tripping state, and the handle lever 5 is in the closing position, the center of the first hinged portion 11 is located on the side of the main spring 8 facing the locking lever 2; at the same time, the re-locking pusher 51 is located on the side of the line connecting the center point of the second hinged portion 12 and the center point of the first hinged portion 11 away from the locking lever 2.

[0024] Please continue reading Figure 1 , the operating mechanism of the circuit breaker is in the closing position. If the opening operation is performed at this time, a torque in the opening direction is first applied to the handle lever 5 to make the handle lever 5 move in the direction of the lock lever 2. In this process, when the main spring 8 passes through the center point of the first hinge 11, the direction of the torque generated by the main spring 8 on the upper connecting rod 3 and the lower connecting rod 4 will change, so that the upper connecting rod 3 and the lower connecting rod 4 also move in the direction of the lock lever 2 and drive the rotating shaft 9 to rotate until the rotating shaft 9 stops after it reaches the position, thereby completing the opening action. Preferably, the first hinge 11 is a hole.

[0025] Please refer to Figure 2 Combined with Figure 7, the operating mechanism of the circuit breaker is in the opening position. If the closing operation is performed at this time, a closing direction torque is first applied to the handle lever 5 to make the handle lever 5 move in the direction away from the lock lever 2. In this process, when the main spring 8 passes the center point of the first hinge 11, the direction of the torque generated by the main spring 8 on the upper connecting rod 3 and the lower connecting rod 4 will change, so that the upper connecting rod 3 and the lower connecting rod 4 also move in the direction away from the lock lever 2 and drive the rotating shaft 9 to rotate until the limiter 31 on the upper connecting rod 3 contacts the tripping lever 1 and stops moving, thereby completing the closing action and the operating mechanism returns to the closing position. Preferably, the limiter 31 is a round shaft.

[0026] Please refer to Figure 3 When the operating mechanism is in the closed state, the tripping action can be performed. Specifically, the locking lever 2 is pushed in the direction away from the tripping lever 1 to unlock the operating mechanism. After the locking lever 2 is opened to a certain angle, the tripping lever 1 will no longer be constrained, and then it will open upward under the pulling force of the main spring 8. At this time, the upper connecting rod 3 and the lower connecting rod 4 will also move upward with the tripping lever 1, and drive the rotating shaft 9 to rotate until the rotating shaft 9 stops after it is in place, and the upper connecting rod 3 and the lower connecting rod 4 reach the tripping position.

[0027] Please refer to Figure 4 , when the upper connecting rod 3 and the lower connecting rod 4 reach the tripping position, the handle lever 5 will continue to move and stabilize to the tripping position, and the re-locking action can be performed at this time. Specifically, a torque in the opening direction is applied to the handle lever 5, so that the handle lever 5 moves in the direction of the lock lever 2. During this movement, the re-locking pusher 51 on the handle lever 5 will contact the tripping lever 1 and push the tripping lever 1 to rotate downward. After reaching the locking position with the lock lever 2, it is only necessary to reset the lock lever 2 so that it can lock the tripping lever 1 again. At the same time, the upper connecting rod 3 and the lower connecting rod 4 move with the tripping lever 1, and finally all parts will return to the position of the opening state, completing the re-locking action. Preferably, the re-locking pusher 51 is a round shaft.

[0028] Please continue to refer to Figure 3 The conventional operating mechanism does not have a limit member 31 on the upper connecting rod 3, so Figure 3In the state shown, the five-link system composed of the tripping lever 1, the upper connecting rod 3, the lower connecting rod 4 and the rotating shaft 9 has two degrees of freedom, and thus it is necessary to set constraints on the two parts to maintain a unique position state. However, in this embodiment, due to the additional limiter 31 and the relative position relationship of the first hinged portion 11, the torque direction of the upper connecting rod 3 during the tripping operation of the operating mechanism can be ensured, so that the tripping lever 1 and the upper connecting rod 3 are always in contact and maintain a fixed relative position relationship throughout the process. At this time, only a limit constraint is required to be set on the rotating shaft 9 to maintain the overall stable state.

[0029] On the contrary, in the same state, if the limit shaft 31 is not provided, the upper connecting rod 3 will not be able to maintain a relative contact position with the tripping lever 1, that is, it will become a conventional five-link mechanism and cannot maintain the positional relationship shown in the figure. Specifically, the handle lever 5 will drive the upper connecting rod 3 to rotate in the closing direction in the closing position, and the rotating shaft 9 will move at the same time. At this time, the moving and static contacts cannot maintain the maximum opening position, and as long as the center point of the first hinged part 11 is on the right side of the main spring 8, the torque direction can be maintained, which causes the handle lever 5 and the upper connecting rod 3 to be unable to reset and locked in this position, that is, self-locking; and after the limit member 31 is provided, the tripping lever 1 is in stable contact with the upper connecting rod 3, which can ensure that the rotating shaft 9 is always maintained in the open position. At this time, even if the handle lever 5 is subjected to force from the main spring 8 and reaches the tripping stable state where the re-buckle push member 51 contacts the tripping lever 1, it will not affect the upper connecting rod 3 and the rotating shaft 9. At the same time, since the handle lever 5 is generally in the closing position at the initial state of the tripping action, and the direction of the torque of the main spring 8 on the upper connecting rod 3 always depends on the positional relationship between the main spring 8 and the first hinge 11, when the upper connecting rod 3 and the lower connecting rod 4 reach the tripping position, the center point of the first hinge 11 needs to be kept on the side of the main spring 8 that is biased toward the lock lever 2, so that the upper connecting rod 3 and the tripping lever 1 are kept in contact. If the center point of the first hinge 11 is located on the other side of the main spring 8, the torque of the tripping lever 1 on the upper connecting rod 3 is in the opening direction, and the contact positions of the two are separated, resulting in the inability to maintain the state of the four-bar linkage.

[0030] Furthermore, in order to make the limiter 31 stably contact the tripping lever 1, the rotation center of the tripping lever 1 needs to be designed in a higher area to follow the contact position of the limiter 31. Since the tripping lever 1 is always opened upward during the tripping action, its action area will be greatly moved upward. When the tripping lever 1 is re-engaged, the handle lever 5 needs to be used to push the tripping lever 1. If a conventional design structure is adopted here, the re-engagement pusher 51 needs to push the tripping lever 1 from top to bottom, so it needs to be set above the tripping lever 1 and close to the side of the locking lever 2, such as Figure 5The re-buckle shaft 52 is located in the conventional design position, which requires a large upper space, and when the re-buckle shaft 52 moves to the right after the handle is moved, it also needs to occupy the space near the lock lever 2, which will increase the height and width occupied by the mechanism at the same time, and it is inevitable that the design requirements cannot be met for a miniaturized mechanism.

[0031] See also Figure 6 In this embodiment, the re-buckle pusher 51 is arranged on the left side of the tripping lever 1, that is, the line connecting the center point of the second hinged portion 12 and the center point of the first hinged portion 11 is located on the side away from the locking lever 2, referring to Figure 6 The shaded area does not occupy height space, and the left side of the operating mechanism is generally an arc extinguishing chamber or other installation space. The arrangement of the push member 51 here will not increase the overall width, and can meet the requirements of miniaturized design.

Claims

1. An operating mechanism of a low-voltage circuit breaker, comprising a tripping lever (1), a locking lever (2), an upper connecting rod (3), a lower connecting rod (4), a handle lever (5), a connecting shaft (6), a side plate (7), a main spring (8), a rotating shaft (9) and a common pivot shaft (10), wherein the tripping lever (1), the locking lever (2) and the handle lever (5) are rotatably arranged on the side plate (7), and a re-locking pusher (51) is arranged on the handle lever (5), and the re-locking pusher (51) drives the tripping lever (1) to rotate, so that the tripping lever (1) and the locking lever (2) are contacted and locked; the upper connecting rod (3) and the lower connecting rod (4) are pivotally connected via a connecting shaft (6); one end of the main spring (8) is hung on the handle lever (5), and the other end of the main spring (8) is hung on the connecting shaft (6); the rotating shaft (9) is connected to the lower connecting rod (4) via a common pivot shaft (10), and the rotating shaft (9) is rotated by the movement of the lower connecting rod (4); the tripping lever (1) is provided with a first hinged portion (11) hinged to the upper connecting rod (3) and a second hinged portion (12) hinged to the side plate (7), the second hinged portion (12) constituting the rotation center of the tripping lever (1), characterized in that: A limit member (31) is provided on the upper connecting rod (3), and the limit member (31) contacts and cooperates with the tripping lever (1) during the tripping process of the low-voltage circuit breaker, so that the tripping lever (1) and the upper connecting rod (3) maintain a fixed relative position relationship; when the upper connecting rod (3) and the lower connecting rod (4) are in the position of the low-voltage circuit breaker tripping state, and the handle lever (5) is in the closing position, the center of the first hinged part (11) is located on the side of the main spring (8) facing the locking lever (2); at the same time, the re-locking push member (51) is located on the side of the line connecting the center point of the second hinged part (12) and the center point of the first hinged part (11) away from the locking lever (2).

2. The operating mechanism of a low voltage circuit breaker according to claim 1, characterized in that The re-fastening pusher (51) is a round shaft, a semi-circular shaft or a round boss.

3. The operating mechanism of a low voltage circuit breaker according to claim 1, characterized in that The limiting member (31) is a circular shaft, a semicircular shaft or a circular boss.

4. The operating mechanism of a low voltage circuit breaker according to claim 1, characterized in that The first hinged portion (11) is a hole or a boss.

5. The operating mechanism of a low voltage circuit breaker according to claim 1, characterized in that The second hinged portion (12) is a hole or a boss.

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