An operating mechanism for a miniature circuit breaker

Abstract

The present invention provides an operating mechanism of a small circuit breaker, comprising a contact support, a lock, a moving contact and a reset spring, wherein a first combination structure is provided between the lock and the contact support, and the lock has a first action state in which it is driven by a driving member of a short-circuit tripping mechanism, and a second action state in which it is linked with the contact support and continues to be driven by the driving member after being combined with the contact support. In this way, when opening the circuit breaker, the contact support is not only subjected to the force of the reset spring, but also to the driving force of the driving member of the short-circuit tripping mechanism. Compared with the prior art, the opening speed of the contact support and the moving contact is faster, and the breaking effect is better.

Description

Technical Field

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

[0002] Circuit breakers are important control and protection equipment in low-voltage power distribution systems. They can quickly interrupt fault currents when overload or short circuit occurs in the power distribution system to protect the power distribution system and electrical equipment. Fault current interrupting capacity is one of the most important performance evaluation indicators of circuit breakers, and the structure and dynamic characteristics of the operating mechanism are key factors affecting the circuit breaker’s interrupting capacity.

[0003] The existing operating mechanism of a small circuit breaker mainly includes a handle, a connecting rod, a contact support, a lock, a tripping catch, a reset spring and a moving contact. When the circuit is closed, the tripping catch and the lock are in a locked state, and the handle drives the contact support to rotate through the connecting rod, thereby driving the moving contact to contact and connect with the static contact; when the circuit is opened, the lock is unlocked from the tripping catch by an external force, and the contact support drives the moving contact to separate and disconnect from the static contact under the action of the reset spring. Generally speaking, the faster the breaking speed, the better the current breaking capacity of the circuit breaker, and the greater the reset spring force required by the operating mechanism. However, this will cause the contact pressure between the moving contact and the static contact to be greater when closed. If the contact pressure is greater than the electric repulsion between the moving and static contacts during breaking, it will affect the normal breaking of the operating mechanism. Therefore, how to improve the breaking speed of the operating mechanism is an important technical problem that needs to be urgently solved in this field. In addition, in order to realize the linkage of multi-stage circuit breakers, a splicing shaft is provided between the locks of two adjacent circuit breakers, that is, when the lock of one of the circuit breakers is unlocked from the tripping buckle under the action of external force, the lock can drive the locks of the remaining circuit breakers to unlock accordingly through the splicing shaft, thereby causing multiple circuit breakers to trip synchronously. However, when the number of circuit breakers is large, the resistance will be large, which will reduce the linkage opening speed of the multi-stage circuit breakers. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defect of the ordinary breaking speed of the operating mechanism in the prior art, thereby providing an operating mechanism of a small circuit breaker with a fast breaking speed.

[0005] To this end, the present invention provides an operating mechanism of a small circuit breaker, comprising a housing, and a contact support, a lock, a moving contact and a reset spring arranged on the housing, wherein the reset spring is suitable for driving the contact support to reset, a first coupling structure is arranged between the lock and the contact support, and the lock has a first action state driven by a driving member of a short-circuit tripping mechanism, and a second action state in which the lock is linked with the contact support and continues to be driven by the driving member after coupling.

[0006] The first combining structure includes a first matching block and a first stop block. The first matching block is arranged on the lock buckle and is arranged opposite to the driving member. The first stop block is arranged on the contact support and is arranged opposite to a side of the first matching block away from the driving member. The first stop block can be against the first matching block and driven by it.

[0007] A second coupling structure is also provided between the contact support and the lock catch, and the second coupling structure is suitable for driving the lock catch to rotate in the same direction when the contact support moves in the opening direction.

[0008] The second combining structure comprises a second stop block arranged on the contact support, and a second matching block arranged on the lock catch and capable of abutting against the second stop block.

[0009] It also includes a lock buckle torsion spring suitable for driving the lock buckle to reset, one end of the lock buckle torsion spring abuts against the second stop block, and the other end abuts against the third stop block on the lock buckle.

[0010] The second stop block and the third stop block are both in an inverted L shape, and the inverted L-shaped second stop block and the third stop block have slots for corresponding assembly of the two ends of the lock torsion spring.

[0011] A first limiting structure suitable for limiting the contact support from jumping along the Z-axis direction of the shell is provided between the shell and the contact support. The first limiting structure includes a convex column provided on the contact support and a stopper provided on the inner side of the shell and corresponding to the convex column.

[0012] The short-circuit tripping mechanism comprises a coil, wherein the coil has a coil body and a connecting portion connected to the stationary contact, and a convex column is arranged between the connecting portion and the moving contact.

[0013] The contact support has a first blocking surface arranged at the bottom thereof and suitable for blocking the arc from moving upwards. The first blocking surface is an arc surface distributed with the rotation center of the contact support as the center of the circle.

[0014] The reset spring is a tension spring arranged between the housing and the contact support, and the tension spring is suitable for driving the contact support to reset and for providing contact pressure between the moving contact and the static contact.

[0015] The technical solution of the present invention has the following advantages:

[0016] 1. The operating mechanism of the miniature circuit breaker provided by the present invention comprises a contact support, a lock, a moving contact and a reset spring, wherein a first combination structure is provided between the lock and the contact support, and the lock has a first action state in which it is driven by a driving member of a short-circuit tripping mechanism, and a second action state in which it is linked with the contact support and continues to be driven by the driving member after being combined with the contact support. Thus, when opening the circuit breaker, the contact support is not only subjected to the force of the reset spring, but also to the driving force of the driving member of the short-circuit tripping mechanism. Compared with the prior art, the opening speed of the contact support and the moving contact is faster, and the breaking effect is better.

[0017] 2. The operating mechanism of the miniature circuit breaker provided by the present invention, the first coupling structure includes a first mating block provided on the latch, and a first stop block provided on the contact support and capable of abutting against the first mating block. The first mating block can be driven by the driving member to achieve tripping, and can also abut against the first stop block to realize the linkage between the latch and the contact support. In this way, the structure is simpler and the production cost is reduced.

[0018] 3. The operating mechanism of the miniature circuit breaker provided by the present invention, a second coupling structure is further provided between the contact support and the latch. The second coupling structure is adapted to drive the latch to rotate in the same direction when the contact support moves in the opening direction, so that the latch can utilize the larger restoring force of the return spring to drive other latches of the multi-pole circuit breaker to act synchronously and quickly, improving the reliability.

[0019] 4. The operating mechanism of the miniature circuit breaker provided by the present invention, the second coupling structure includes a second stop block provided on the contact support, and a second mating block provided on the latch and capable of abutting against the second stop block. The second stop block can drive the latch to perform an opening action by driving the second mating block, and can also abut against one end of the latch torsion spring. In this way, the structure is simpler and the production cost is reduced.

[0020] 5. The operating mechanism of the miniature circuit breaker provided by the present invention, both the second stop block and the third stop block are in an inverted L shape. The inverted L-shaped second stop block and third stop block have slots for respectively assembling the two ends of the latch torsion spring, so as to prevent the two ends of the latch torsion spring from falling off, further improving the reliability.

[0021] 6. The operating mechanism of the miniature circuit breaker provided by the present invention, a first limiting structure adapted to limit the jumping of the contact support along the Z-axis direction of the housing is provided between the housing and the contact support, so as to improve the contact reliability between the moving contact and the static contact; the first limiting structure includes a convex column provided on the contact support, and a stop block provided on the inner side surface of the housing and corresponding to the convex column. The convex column is provided between the connecting portion of the coil and the moving contact. In this way, the convex column can, on the one hand, prevent the contact support from jumping along the Z-axis direction of the housing, and on the other hand, can increase the electrical gap between the coil and the moving contact during closing, further improving the reliability.

[0022] 7. The operating mechanism of the miniature circuit breaker provided by the present invention, the contact support has a first blocking surface provided at its bottom and adapted to block the upward movement of the arc. During the breaking process, due to the blocking of the first blocking surface on the arc, the arc is forced to move towards the lower arc chute and the arc extinguishing chamber, increasing the stability of the arc movement direction and improving the arc extinguishing ability. In addition, the first blocking surface is an arc surface distributed with the rotation center of the contact support as the center of the circle. In this way, when the contact support rotates, the distance between the first blocking surface and the static contact always remains unchanged, thus avoiding the situation that part of the arc moves upward to the mechanism due to the change of the distance.

[0023] 8. The operating mechanism of the miniature circuit breaker provided by the present invention, the tension spring is both adapted to drive the contact support to reset and to provide the contact pressure between the moving contact and the static contact. During the closing process, the tension of the tension spring increases linearly. When the moving contact and the static contact just come into contact, the initial tension of the tension spring on the contact support and the moving contact is relatively large, which can reduce the mechanical bounce of the moving contact and avoid welding. In the prior art, in addition to the reset spring for driving the contact support to reset, a contact spring for providing contact pressure is also provided. In this way, from the start of closing to when the moving contact and the static contact just come into contact, the initial pressure of the contact spring on the moving contact is very small, and the mechanical bounce amplitude of the moving contact is relatively large, and it is very easy to weld. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required to be used in the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0025] Figure 1 It is an assembly schematic diagram of the operating mechanism of the miniature circuit breaker of the present invention and the housing;

[0026] Figure 2 is Figure 1 the front view of;

[0027] Figure 3 is Figure 2 the enlarged structural schematic diagram of part A in;

[0028] Figure 4 It is a structural schematic diagram of another angle of the operating mechanism of the miniature circuit breaker;

[0029] Figure 5 is Figure 4 the enlarged structural schematic diagram of part B in;

[0030] Figure 6 It is the front view of the operating mechanism;

[0031] Figure 7 Rear view of the operating mechanism;

[0032] Figure 8 Exploded structural schematic diagram of the latch and the bimetallic pull rod;

[0033] Figure 9 Stereogram of the contact support;

[0034] Figure 10 Exploded structural schematic diagram of the contact support and the moving contact;

[0035] Figure 11 Assembly schematic diagram of the contact support, the bimetallic pull rod and the housing;

[0036] Figure 12 For Figure 11 Enlarged structural schematic diagram of part C in

[0037] Figure 13 Assembly schematic diagram of the coil, the moving contact and the housing;

[0038] Figure 14 Stereogram of the moving contact.

[0039] Explanation of reference numerals: 1. Housing; 2. Contact support; 3. Latch; 4. Moving contact; 5. Driving member; 6. First mating block; 7. First stop block; 8. Second stop block; 9. Second mating block; 10. Latch torsion spring; 11. Third stop block; 12. Convex post; 13. Block; 14. Coil; 15. Coil body; 16. Stationary contact; 17. Connecting portion; 18. First blocking surface; 19. Return spring; 20. Mounting portion; 21. Contact head portion; 22. Protruding portion; 23. Mounting groove; 24. Block; 25. Guide inclined surface; 26. Bimetallic pull rod; 27. First end; 28. Second end; 29. Bimetallic sheet; 30. Boss; 31. Jack; 32. Limiting surface; 33. Limiting block; 34. Waist-shaped hole; 35. First blocking surface; 36. Second blocking surface; 37. Handle; 38. Link; 39. Jumping latch. Detailed implementation manners

[0040] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0041] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0042] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0044] Example

[0045] This embodiment provides a miniature circuit breaker, such as Figure 1 As shown, it includes an operating mechanism and a short-circuit tripping mechanism arranged on a housing 1, wherein the operating mechanism includes a handle 37, a connecting rod 38, a tripping buckle 39, a lock buckle 3, a contact support 2, a moving contact 4, a reset spring 19, a lock buckle torsion spring 10, and a double metal pull rod 26; the short-circuit tripping mechanism includes a coil 14, a moving iron core, a static iron core and a driving member 5, wherein the coil 14 has a coil body 15 and a connecting portion 17 connected to the static contact 16.

[0046] The lock catch 3 is rotatably mounted on the housing 1 through a rotating shaft. The lock catch 3 can be locked with the trip catch 39 when the switch is closed, and unlocked with the trip catch 39 when the switch is opened. A first combination structure and a second combination structure are provided between the lock catch 3 and the contact support 2. The lock catch 3 has a first action state driven by the driving member 5 of the short-circuit tripping mechanism, and a second action state in which the lock catch 3 is linked with the contact support 2 and continues to be driven by the driving member 5.

[0047] like Figure 4 , 5As shown in FIGS. 6 and 7, the first engaging structure includes: a first mating block 6 provided on the latch 3 and disposed opposite to the driving member 5; a first stop block 7 provided on the outer wall of the contact support 2 and disposed opposite to a surface of the first mating block 6 away from the driving member 5. The first stop block 7 can abut against the first mating block 6 and be driven by it. The first mating block 6 can be driven by the driving member 5 to achieve tripping, and can also abut against the first stop block 7 to realize the linkage between the latch 3 and the contact support 2. In this way, only one first mating block 6 needs to be provided, the structure is simpler, and the production cost is reduced. In this embodiment, the driving member 5 is a push rod.

[0048] As a variable embodiment, a third mating block (not shown in the figure) that cooperates with the first stop block 7 is provided on the latch 3, and the third mating block is separately provided from the first mating block 6.

[0049] As Figure 2 and 6 shown, the second engaging structure includes a second stop block 8 provided on the contact support 2, and a second mating block 9 provided on the latch 3 and capable of abutting against the second stop block 8. In this embodiment, the second stop block 8 is located between the coil body 15 and the second mating block 9. In this way, during opening, the latch 3 can utilize the relatively large restoring force of the return spring 19 to drive other latches 3 of the multi-pole circuit breaker to act synchronously and quickly, improving the reliability.

[0050] The latch 3, as Figure 2 、 3 shown in FIGS. 6 and 8, is formed with a jack 31 for inserting the first end 27 of the bimetal pull rod 26. A boss 30 adapted to limit the rotation angle of the bimetal pull rod 26 is provided at the top edge of the jack 31, so that the second end 28 of the bimetal pull rod 26 is in a separated state from the bimetal sheet 29 at the opening position. Compared with the prior art in which the second end 28 of the bimetal pull rod 26 overlaps with the bimetal sheet 29, resulting in a relatively short creepage distance between the bimetal pull rod 26 and the static contact 16, this way has higher safety and reliability. As Figure 8 shown, one side of the boss 30 adjacent to the jack 31 has a limiting surface 32 that cooperates with the main body of the bimetal pull rod 26, and the side away from the jack 31 has a second blocking surface 36 adapted to block metal spatter from entering the jack 31 during breaking. In this way, the situation of the latch 3 being stuck due to metal spatter entering the jack 31 of the latch 3 (that is, the first end of the bimetal pull rod is stuck and cannot rotate relative to the latch 3) is avoided, improving the reliability. In this embodiment, the limiting surface 32 is an inclined surface.

[0051] The latch torsion spring 10 is adapted to drive the latch 3 to reset, as Figure 6As shown, one end of the latch torsion spring 10 abuts against the second stop block 8, and the other end abuts against the third stop block 11 on the latch 3. Both the second stop block 8 and the third stop block 11 are in an inverted L shape, and the inverted L-shaped second stop block 8 and the third stop block 11 have card slots for respectively assembling the two ends of the latch torsion spring 10.

[0052] The contact support 2 is rotatably mounted on the housing 1 through a rotating shaft. A first limiting structure is provided between the contact support 2 and the housing 1 and is adapted to limit the jumping of the contact support 2 along the Z-axis direction of the housing 1. As Figure 11 and 12 shown, the first limiting structure includes a convex column 12 provided on the contact support 2 and a stop block 13 provided on the inner side surface of the housing 1 and corresponding to the convex column 12. In this embodiment, as Figure 2 and 3 shown, the convex column 12 is provided between the mounting portion 20 of the moving contact 4 and the connecting portion 17 of the coil 14. In this way, on the one hand, the convex column 12 plays a role in preventing the contact support 2 from jumping along the Z-axis direction of the housing 1, and on the other hand, it can increase the electrical clearance between the connecting portion 17 of the coil 14 and the mounting portion 20 of the moving contact 4 during closing, further improving the reliability. The contact support 2 has a first blocking surface 18 provided at its bottom and adapted to block the upward movement of the arc. The first blocking surface 18 is an arc surface distributed with the rotation center of the contact support 2 as the center of the circle. As Figure 9 and 10 shown, the contact support 2 is formed with an eight-shaped waist-shaped hole 34 for inserting and fixing the hook of the tension spring. One side of the waist-shaped hole 34 is the small-hole end, and the other side is the large-hole end. Among them, when the tension spring is in a stressed state, the hook is located at the small-hole end of the waist-shaped hole 34. During assembly, the hook of the tension spring can extend in from the large-hole end, making the assembly more rapid and convenient; and when the tension spring is in a stressed state, the hook is located at the small-hole end of the waist-shaped hole 34, so that the swinging amplitude of the tension spring is smaller, ensuring uniform force on the contact support 2. A mounting groove 23 adapted to the mounting portion 20 is formed on the surface of the contact support 2 away from the connecting portion 17. The side wall of the mounting groove 23 has two clamping blocks 24 that abut against the mounting portion 20 to make the mounting portion 20 and the mounting groove 23 connected in an interference fit. A guiding inclined surface 25 is provided at the front end of the clamping block 24 along the insertion direction of the mounting portion 20.

[0053] The return spring 19 is a tension spring provided between the housing 1 and the contact support 2. Hooks are respectively provided at both ends of the tension spring. The tension spring is adapted to drive the contact support 2 to return and is adapted to provide the contact pressure between the moving contact 4 and the static contact 16.

[0054] The moving contact 4, as Figure 13 and 14As shown, it includes a mounting portion 20 adapted to be assembled with the contact support 2, and a contact portion 21 disposed opposite to the static contact 16. The mounting portion 20 and the contact portion 21 are integrally bent and connected, and the bending direction is set away from the connecting portion 17. In this way, the creepage distance between the mounting portion 20 at the upper end of the moving contact 4 and the connecting portion 17 of the coil 14 is increased, and the safety and reliability are improved. In this embodiment, the connecting portion 17, the contact portion 21, and the mounting portion 20 are sequentially distributed along the Z-axis direction of the housing 1. The mounting portion 20 is provided with a convex portion 22 for welding and positioning the flexible connection. The convex portion 22 can not only increase the firmness of the welding, but also be used for welding and positioning the flexible connection, improving the consistency of the product.

[0055] The housing 1 is provided with a second limiting structure adapted to limit the position of the bimetal pull rod 26. The second limiting structure includes two limiting blocks 33 respectively disposed on both sides of the main body width direction of the bimetal pull rod 26. The contact surface between the limiting block 33 and the main body of the bimetal pull rod 26 is an arc surface.

[0056] The operating mechanism of the miniature circuit breaker provided by the present invention includes a contact support 2, a latch 3, a moving contact 4, and a return spring 19. A first coupling structure is provided between the latch 3 and the contact support 2. The latch 3 has a first action state driven by the driving member 5 of the short-circuit tripping mechanism, and a second action state in which it is coupled with the contact support 2 and continues to be driven by the driving member 5. In this way, during opening, in addition to the acting force of the return spring 19, the contact support 2 will also be subjected to the driving force of the driving member 5 of the short-circuit tripping mechanism. Compared with the prior art, the opening speed of the contact support 2 and the moving contact 4 is faster, and the breaking effect is better.

[0057] Obviously, the above embodiments are only examples for clear illustration and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or variations derived therefrom are still within the protection scope of the present invention.

Claims

1. An operating mechanism of a miniature circuit breaker, comprising a housing (1), and a contact support (2), a lock (3), a moving contact (4) and a reset spring (19) arranged on the housing (1), wherein the reset spring is suitable for driving the contact support (2) to reset. It is characterized in that A first combination structure is provided between the lock catch (3) and the contact support (2); the lock catch (3) has a first action state in which it is driven by the driving member (5) of the short-circuit tripping mechanism, and a second action state in which it is linked with the contact support (2) and continues to be driven by the driving member (5); after the lock catch (3) is combined with the contact support (2), the contact support (2) is simultaneously driven by the reset spring and the driving member (5) of the short-circuit tripping mechanism; the first combination structure comprises: a first matching block (6), which is provided on the lock catch (3) and is arranged opposite to the driving member (5); and a first stop block (7), which is provided on the contact support (2) and is arranged opposite to a side of the first matching block (6) away from the driving member (5); the first stop block (7) can abut against the first matching block (6) and be driven thereby.

2. The operating mechanism of the miniature circuit breaker according to claim 1, It is characterized in that A second coupling structure is also provided between the contact support (2) and the lock catch (3), and the second coupling structure is suitable for driving the lock catch (3) to rotate in the same direction when the contact support (2) moves in the opening direction.

3. The operating mechanism of the miniature circuit breaker according to claim 2, It is characterized in that The second combining structure comprises a second stop block (8) arranged on the contact support (2), and a second matching block (9) arranged on the lock buckle (3) and capable of abutting against the second stop block (8).

4. The operating mechanism of the miniature circuit breaker according to claim 3, It is characterized in that It also includes a lock torsion spring (10) suitable for driving the lock (3) to reset, one end of the lock torsion spring (10) abuts against the second stop block (8), and the other end abuts against the third stop block (11) on the lock (3).

5. The operating mechanism of the miniature circuit breaker according to claim 4, It is characterized in that The second stop block (8) and the third stop block (11) are both in an inverted L shape, and the inverted L-shaped second stop block (8) and the third stop block (11) have slots for correspondingly assembling the two ends of the lock torsion spring (10).

6. The operating mechanism of the miniature circuit breaker according to claim 1, It is characterized in that A first limiting structure suitable for limiting the movement of the contact support (2) along the Z-axis direction of the housing (1) is provided between the housing (1) and the contact support (2), the first limiting structure comprising a boss (12) provided on the contact support (2), and a stopper (13) provided on the inner side surface of the housing (1) and corresponding to the boss (12).

7. The operating mechanism of the miniature circuit breaker according to claim 6, It is characterized in that The short-circuit tripping mechanism includes a coil (14), the coil (14) having a coil body (15) and a connecting portion (17) connected to the static contact (16), and a stud (12) is provided between the connecting portion (17) and the moving contact (4).

8. The operating mechanism of the miniature circuit breaker according to claim 1, characterized in that the contact support (2) has a first blocking surface (18) provided at its bottom and adapted to block the upward movement of the arc, and the first blocking surface (18) is an arc surface distributed with the rotation center of the contact support (2) as the center of the circle.

9. The operating mechanism of the miniature circuit breaker according to claim 1, characterized in that the return spring (19) is a tension spring provided between the housing (1) and the contact support (2), and the tension spring is adapted to drive the contact support (2) to return and is adapted to provide the contact pressure between the moving contact (4) and the static contact (16).

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