Magnetic release and circuit breaker having the same

Abstract

The present invention relates to a magnetic release and a circuit breaker with the magnetic release. The magnetic release comprises an armature and an elastic reset part for driving the armature to reset, and further comprises a first permanent magnet located in the middle, and a second permanent magnet and a third permanent magnet located on both sides of the first permanent magnet at equal intervals. The two sides of the first permanent magnet and the second permanent magnet and the third permanent magnet on both sides are arranged with different polarities. The first permanent magnet serves as a first magnetic end, and the second permanent magnet and the third permanent magnet constitute a second magnetic end. Any one of the first magnetic end and the second magnetic end follows the deformation stroke of the elastic reset part, and the other opposite to it is fixedly arranged. Therefore, in the deformation stroke of the elastic reset part, the reset force of the first magnetic end and the second magnetic end is superimposed and intervened by the mutual magnetic force of the first magnetic end and the second magnetic end, so as to help the armature overcome the elastic restoring force of the elastic reset part when the armature moves, and maximize the elastic restoring force to ensure the reset of the armature after the armature unlocking movement is completed.

Description

Technical Field

[0001] The invention relates to the technical field of circuit breaker manufacturing, and in particular to the improvement of a magnetic release. Background Art

[0002] The magnetic release is one of the components of the molded case circuit breaker. It consists of a conductor, an armature, a yoke, a support, a push rod, a reaction spring, etc. The conductor passes through the yoke. When a certain current passes through the conductor, due to the electromagnetic induction phenomenon, a magnetic flux is generated in the armature, the yoke and the air gap between them. Its magnetic lines of force are a closed curve around the conductor, and an electromagnetic attraction is generated between the armature and the yoke. Since the yoke is fixed, the armature moves toward the yoke under the action of the electromagnetic attraction, and the push rod fixedly connected to the armature impacts and drags the circuit breaker locking mechanism to unlock it. The circuit breaker then completes the tripping and breaking functions, cuts off the fault current, and protects the safety of the line and equipment.

[0003] Among them, the function of the reaction spring is to meet the vibration resistance requirements of the circuit breaker and prevent it from unlocking itself during the vibration process; secondly, when the armature moves toward the yoke, the reaction spring will be compressed and store energy. When the conductor current disappears, the reaction spring drives the armature to reset with its elastic restoring force. However, such a structure has a disadvantage, that is, when the armature moves toward the yoke, it needs to overcome the elastic restoring force of the reaction spring. Under a smaller current, the electromagnetic suction force is smaller, and the armature cannot overcome the elastic restoring force of the reaction spring, so the locking mechanism cannot be unlocked to complete the disconnection function. Summary of the invention

[0004] Therefore, in view of the above problems, the present invention proposes a magnetic release with optimized structure and a circuit breaker having the magnetic release, which helps the armature to overcome the elastic restoring force of the reaction spring by adding a permanent magnet acceleration structure.

[0005] The present invention is implemented by the following technical solutions:

[0006] The present invention provides a magnetic release for sensing current passing through a conductor and driving a locking mechanism of a circuit breaker to unlock. The magnetic release comprises an armature and an elastic reset member, wherein the armature has a motion stroke for realizing unlocking of the locking mechanism, and the elastic reset member applies a reset force to the armature through its deformation stroke. The magnetic release also comprises a first permanent magnet located in the middle, and a second permanent magnet and a third permanent magnet located on both sides of the first permanent magnet at equal intervals, wherein the two sides of the first permanent magnet and the second permanent magnet and the third permanent magnet on both sides thereof are arranged with different polarities, the first permanent magnet serves as a first magnetic end, and the second permanent magnet and the third permanent magnet constitute a second magnetic end, and any one of the first magnetic end and the second magnetic end moves with the deformation stroke of the elastic reset member, and the other one of the first magnetic end and the second magnetic end is fixedly arranged, so that in the deformation stroke of the elastic reset member, the reset force thereof is superimposed and intervened by the mutual magnetic force between the first magnetic end and the second magnetic end.

[0007] In order to help the armature overcome the elastic restoring force of the elastic restoring part during the movement of the armature and increase the elastic restoring force of the elastic restoring part at the end of the unlocking movement stroke of the armature, through the relative movement of the first magnetic end and the second magnetic end, the mutual magnetic force of the first magnetic end and the second magnetic end applies a reverse force on the elastic restoring part in the early, middle and late stages of the deformation stroke, which changes from small to large and then from large to small.

[0008] Among them, preferably, in the early to middle stage of the deformation stroke, the second permanent magnet and the third permanent magnet simultaneously attract the first permanent magnet to approach, thereby applying a reverse force that gradually increases from small to large to the elastic return member, and in the middle to late stage of the deformation stroke, the first permanent magnet is inserted between the second permanent magnet and the third permanent magnet, thereby applying a reverse force that gradually decreases from large to small to the elastic return member.

[0009] In order to maximize the elastic restoring force and ensure the resetting of the armature after the unlocking movement of the armature is completed, in one embodiment, the first permanent magnet is finally inserted into the center position of the second permanent magnet and the third permanent magnet so that the attraction of the second permanent magnet and the third permanent magnet on the first permanent magnet offsets each other.

[0010] Wherein, based on installation and manufacturing considerations, in one embodiment, the first permanent magnet, the second permanent magnet and the third permanent magnet are sheet structures with the same specifications.

[0011] In one embodiment, the movement stroke of the armature is linear movement, and the elastic return member is a tension spring or a compression spring; or, in another embodiment, the movement stroke of the armature is swinging, and the elastic return member is a torsion spring.

[0012] Among them, based on installation and manufacturing considerations, in one embodiment, the magnetic release also includes an unlocking member, a guide rod and a supporting member, the supporting member is fixedly arranged, a guide hole is opened on the supporting member, the guide rod extends in the guide hole, the armature is fixedly connected to the guide rod, the elastic reset member is a compression spring sleeved on the guide rod, the unlocking member is sleeved on the guide rod and buckled on the compression spring, one end of the compression spring abuts against the unlocking member, and the other end abuts against the supporting member, the first permanent magnet is fixedly connected to the unlocking member, the second permanent magnet and the third permanent magnet are fixedly connected to the supporting member, when the armature moves, it drives the unlocking member to unlock the locking mechanism and compress the compression spring to make the compression spring produce the deformation stroke, so that the first magnetic suction end fixedly connected to the unlocking member follows the deformation stroke of the elastic reset member.

[0013] To meet the design requirements of different tripping currents of the circuit breaker, in one embodiment, the distances between the second permanent magnet and the third permanent magnet and the first permanent magnet are adjustable.

[0014] Based on the above-mentioned magnetic release, the present invention further provides a circuit breaker, comprising a locking mechanism and the above-mentioned magnetic release.

[0015] The present invention has the following beneficial effects: the present invention forms a permanent magnet acceleration mechanism by arranging the first permanent magnet, the second permanent magnet and the third permanent magnet. In the early stage of the deformation stroke of the elastic reset part, the permanent magnetic suction force is small, which will not affect the movement of the armature and can meet the seismic requirements; in the middle stage of the deformation stroke of the elastic reset part, the permanent magnetic suction force gradually increases, helping the armature to overcome the elastic restoring force of the elastic reset part, and the armature can complete the movement process under a relatively small current, realize tripping and disconnection, and ensure the safety of electricity use; in the late stage of the deformation stroke of the elastic reset part, the permanent magnetic suction forces offset each other, the elastic restoring force of the elastic reset part is the largest, and the reset of the armature is ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic diagram of the three-dimensional structure of the circuit breaker in Example 1 (part 1);

[0017] Figure 2 is a schematic diagram of the three-dimensional structure of the circuit breaker in Example 1 (part 2);

[0018] Figure 3 is a structural exploded view of the circuit breaker in Example 1;

[0019] Figure 4 is a schematic diagram of the three-dimensional structure of the magnetic release in Example 1;

[0020] Figure 5 is a structural exploded view of the magnetic release in Example 1;

[0021] Figure 6 It is a schematic diagram of a permanent magnetic acceleration mechanism provided on the magnetic release in Example 1;

[0022] Figure 7 is a schematic diagram of the positions of the first permanent magnet, the second permanent magnet and the third permanent magnet when the armature has not yet moved toward the yoke in Example 1;

[0023] Figure 8 is a schematic diagram of the positions of the first permanent magnet, the second permanent magnet and the third permanent magnet during the movement of the armature toward the yoke in Example 1;

[0024] Fig. 9 is a schematic diagram of the positions of the first permanent magnet, the second permanent magnet and the third permanent magnet when the armature in Embodiment 1 ends its first movement stroke toward the yoke;

[0025] Fig.10 It is the elastic restoring force (F) of the compression spring during its compression deformation stroke. N ) and the mutual attraction between the first magnetic end and the second magnetic end (F t )

[0026] Fig.11 It is a curve diagram of the resultant force of the elastic restoring force of the compression spring and the mutual attraction between the first magnetic attraction end and the second magnetic attraction end during the compression deformation stroke of the compression spring. DETAILED DESCRIPTION

[0027] To further illustrate the various embodiments, the present invention provides drawings. These drawings are part of the disclosure of the present invention, which are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, a person of ordinary skill in the art should be able to understand other possible implementations and advantages of the present invention. The components in the figures are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0028] The present invention will now be further described with reference to the accompanying drawings and specific implementation methods.

[0029] See also Figure 1-3 As shown, as a preferred embodiment of the present invention, a circuit breaker is provided, including a base 1 and a contact system 2 installed on the base 1, an operating mechanism 3, a tripping half-shaft 4 and a magnetic tripper 5. Conventionally, the contact system 2 includes a moving contact and a stationary contact, and the circuit breaker is turned on and off by the motion trajectory of the moving contact relative to the stationary contact. The operating mechanism 3 is linked to the contact system 2. When the moving contact is repelled, the locking mechanism is unlocked (tripped) or the handle is manually pulled, the operating mechanism 3 is linked to the contact system 2 to enable the circuit breaker to quickly complete the opening and closing.

[0030] For ease of description, define Figure 1 The x direction is the length direction of the circuit breaker, the y direction is the width direction of the circuit breaker, and the z direction is the height direction of the circuit breaker.

[0031] In this embodiment, the locking mechanism of the circuit breaker is realized by a hook-shaped tripping piece 31 and a tripping half-shaft 4. The tripping piece 31 is overlapped in a lap groove of the tripping half-shaft 4. When the tripping half-shaft 4 rotates, the tripping piece 31 falls off from the lap groove, thereby linking the operating mechanism 3 and the contact system 2.

[0032] The magnetic release 5 is a device that drives the release half shaft 4 to rotate. Figure 4-5 , and refer to Figure 1, the magnetic release 5 is arranged along the height direction of the circuit breaker, and the magnetic release 5 includes an unlocking plate 51 (as an unlocking member), a guide rod 52, a compression spring 53, a support member 54, an armature 55 and a yoke 56. The support member 54 is fixedly connected to the base 1, and a guide hole 541 is opened on the support member 54. The guide rod 52 extends through the guide hole 541, so that the support member 54 guides the guide rod 52. The support member 54 is a U-shaped sheet structure, so that two coaxial guide holes 541 can be set to improve the guiding and limiting effect of the guide rod 52. The compression spring 53 is sleeved on the guide rod 52, the armature 55 is fixedly connected to the guide rod 52, and the unlocking plate 51 is sleeved on the guide rod 52 and is buckled on the compression spring 53 through a screw lock, so that one end of the compression spring 53 abuts against the unlocking plate 51, and the other end abuts against the support member 54. The yoke 56 and the armature 55 are arranged opposite to each other in the height direction of the circuit breaker. The conductor 21 passes through the yoke 56 and presses the yoke 56 to be fixed on the base 1. For details, refer to Figure 3 , a mounting groove 11 whose opening width roughly matches the thickness of the conductor 21 is provided on the base 1, and a mounting platform 12 is formed on one side of the mounting groove 11. When the conductor 21 is pressed into the mounting groove 11, the yoke 56 is pressed and fixed on the mounting platform 12 of the base 1. In this embodiment, since the yoke 56 and the armature 55 are arranged opposite to each other in the height direction of the circuit breaker, the yoke 56 can be pressed and fixed on the base 1 by using the installation cooperation between the conductor 21 and the base 1, and there is no need to use rivets to fix the yoke and the base as in the prior art, which reduces the number of parts and saves costs.

[0033] When a large current passes through the conductor 21, due to the electromagnetic induction phenomenon, a magnetic flux is generated in the armature 55, the yoke 56 and the air gap therebetween, and its magnetic lines of force are a closed curve around the conductor 21, and an electromagnetic attraction is generated between the armature 55 and the yoke 56. Since the yoke 56 is fixed on the base 1, the armature 55 moves toward the yoke 56 under the action of the electromagnetic attraction (as the first movement stroke of the armature 55) and compresses the compression spring 53 to generate an elastic reset force. The unlocking plate 51 drives the tripping half shaft 4 to rotate under the drive of the armature 55 and the screw lock member that buckles it, thereby unlocking the locking mechanism, and the circuit breaker then completes the tripping and disconnecting functions, cuts off the fault current, and protects the safety of the line and equipment. After the current of the conductor 21 disappears, the compression spring 53 drives the armature 55 to return to the initial position in the direction away from the yoke 56 (as the second movement stroke of the armature 55) with its elastic reset force.

[0034] The magnetic release of this embodiment is of the type that moves up and down, which is different from the conventional swing-strike magnetic release in the prior art. On the one hand, it fully utilizes the height dimension of the circuit breaker, and on the other hand, it is more convenient for installation. Only the support member 54 and the yoke 56 of the entire release are fixedly connected with the base 1, and the remaining components can be installed by simple sleeve setting and screw lock connection, saving installation steps.

[0035] In this embodiment, a permanent magnet acceleration mechanism is also provided. Figure 6 As shown, a first permanent magnet 61 (serving as a first magnetic end) is fixedly connected to the unlocking plate 51, so that the first permanent magnet 61 can move with the movement of the armature 55. A second permanent magnet 62 and a third permanent magnet 63 (serving as a second magnetic end) are fixedly connected to the support member 54, and the second permanent magnet 62 and the third permanent magnet 63 are equidistantly located on both sides of the first permanent magnet, and the two sides of the first permanent magnet 61 and the second permanent magnet 62 and the third permanent magnet 63 on both sides thereof are arranged with different polarities. Figure 7-9 When the armature 55 moves toward the yoke 56, the unlocking plate 51 is driven to compress the compression spring 53. The first permanent magnet 61 fixed on the unlocking plate 51 follows the deformation stroke of the compression spring 53. The second permanent magnet 62 and the third permanent magnet 63 simultaneously attract the first permanent magnet 61 to apply a force on the armature 53 that is opposite to the restoring force of the compression spring 53, thereby helping the armature 55 to overcome the elastic restoring force generated by the compression spring 53 during the compression process. Figure 7 In the initial stage of the deformation stroke of the compression spring 53, the distance between the three permanent magnets is relatively far, and the permanent magnetic attraction F1 and F2 of the second permanent magnet 62 and the third permanent magnet 63 on the first permanent magnet 61 are relatively small. Under the support of the compression spring 53, the armature 55 stays in the initial position, meeting the anti-vibration requirements of the circuit breaker; Figure 8 , the conductor 21 passes the current, the armature 55 moves downward for a distance, in the middle of the deformation travel of the compression spring 53, as the distance between the first permanent magnet 61 and the second permanent magnet 62 and the third permanent magnet 63 is getting closer, the permanent magnetic attraction F1, F2 is greatly increased, and the resultant force F3 along the movement direction of the armature 55 can nearly offset the elastic reset force of the compression spring 53, so that the armature 55 can complete the movement process under a relatively small current, and the circuit breaker is disconnected. Fig. 9 In the later stage of the deformation stroke of the compression spring 53, the first permanent magnet 61 is inserted between the second permanent magnet 62 and the third permanent magnet 63, and the combined force of the permanent magnetic forces F1 and F2 gradually decreases, and the corresponding elastic restoring force offsetting effect on the compression spring 53 gradually weakens. Furthermore, in this embodiment, in the later stage of the deformation stroke of the compression spring 53, the first permanent magnet 61 is finally inserted at the center position of the second permanent magnet 62 and the third permanent magnet 63, and the permanent magnetic forces F1 and F2 are offset each other, so that the elastic restoring force of the compression spring 53 is maximized, which helps to restore the armature 55 to its original position after the conductor current disappears.

[0036] like Fig.10 , showing the elastic restoring force F of the compression spring 53 N And the mutual attraction F between the first magnetic end and the second magnetic end t The curve, Fig.11The resultant force curve of the two is shown. In the early to middle stage of the deformation of the compression spring 53, the resultant force of the two changes from small to large to help the armature 55 move downward. In the middle to late stage of the deformation of the compression spring 53, the first permanent magnet 61 is inserted between the second permanent magnet 62 and the third permanent magnet 63, and the resultant force of the two changes from large to small, so that the elastic restoring force of the compression spring 53 is maximized.

[0037] The distance between the second permanent magnet 62 and the third permanent magnet 63 and the first permanent magnet 61 can be set to be adjustable. For example, the first permanent magnet 61 is set to be fixed with a set screw. When the position needs to be adjusted, the set screw is loosened and the position of the first permanent magnet 61 is adjusted. In addition to the distance between the second permanent magnet 62 (the third permanent magnet 63) and the first permanent magnet 61 in the height direction, the spacing between the second permanent magnet 62 and the third permanent magnet 63 can also be adjusted, which also achieves the effect of adjusting the distance between the second permanent magnet 62 and the third permanent magnet 63 and the first permanent magnet 61. Through this adjustment, and in coordination with the stroke of the compression spring 53 and the armature 55, the design requirements of different tripping currents can be met.

[0038] In the present embodiment, the first permanent magnet 61 follows the deformation stroke of the compression spring 53, while the second permanent magnet 62 and the third permanent magnet 63 are fixedly arranged. In other embodiments, the second permanent magnet 62 and the third permanent magnet 63 can also follow the deformation stroke of the compression spring 53, while the first permanent magnet 61 is fixedly arranged. As long as the two magnetic ends can move relative to each other and generate mutual magnetic force to superimpose the elastic reset force of the compression spring 53, it will be sufficient.

[0039] In this embodiment, the first permanent magnet 61 , the second permanent magnet 62 and the third permanent magnet 63 have completely the same shape and specifications to facilitate manufacturing and installation.

[0040] Although the present embodiment is described by taking a magnetic release with a compression spring as an elastic reset member as an example, it is obvious that the permanent magnet acceleration mechanism in the present embodiment can also be applied to the case where the elastic reset member is a tension spring, such as changing the unlocking plate 51 in the present embodiment to be fixedly connected to the circuit breaker base, and the support member 54 to be not fixed to the circuit breaker base, and the compression spring 53 to be a tension spring with both ends hooked on the unlocking plate 51 and the support member 54.

[0041] Of course, in addition to the mobile magnetic release proposed in this embodiment, the permanent magnetic acceleration mechanism can also be used in a swinging magnetic release, where the armature is attracted by the magnetic yoke to swing, so as to hit the locking mechanism to unlock, and the armature is reset under the action of the torsion spring. According to the movement of the armature, the torsion spring produces a deformation stroke, one of the first magnetic end and the second magnetic end follows the deformation stroke of the torsion spring, and the other is fixedly arranged, and mutual attraction is generated according to the relative movement of the two magnetic ends.

[0042] Although the present invention has been specifically shown and described in conjunction with the preferred embodiments, it should be understood by those skilled in the art that various changes in form and details made to the present invention without departing from the spirit and scope of the present invention as defined in the appended claims will fall within the scope of protection of the present invention.

Claims

1. A magnetic release, used for sensing the current passing through the conductor and driving the locking mechanism of the circuit breaker to unlock, comprising an armature and an elastic reset member, wherein the armature has a motion stroke for realizing the unlocking of the locking mechanism, and the elastic reset member applies a reset force to the armature through its deformation stroke, characterized in that: It also includes a first permanent magnet located in the middle, and a second permanent magnet and a third permanent magnet located on both sides of the first permanent magnet at equal intervals. The two sides of the first permanent magnet and the second permanent magnet and the third permanent magnet on both sides are arranged with different polarities. The first permanent magnet serves as a first magnetic end, and the second permanent magnet and the third permanent magnet constitute a second magnetic end. Any one of the first magnetic end and the second magnetic end can move with the movement of the armature and thus follow the deformation stroke of the elastic return member, and the other one is fixedly arranged. Therefore, in the deformation stroke of the elastic return member, through the relative movement of the first magnetic end and the second magnetic end, a reverse force that superimposes and interferes with its return force is applied to the elastic return member by the mutual magnetic force between the first magnetic end and the second magnetic end.

2. The magnetic release according to claim 1, characterized in that: The superimposed intervention is: through the relative movement of the first magnetic end and the second magnetic end, the mutual magnetic force between the first magnetic end and the second magnetic end applies a reverse force on the elastic reset part in the early, middle and late stages of the deformation stroke, which changes from small to large and then from large to small.

3. The magnetic release according to claim 2, characterized in that: In the early to middle stages of the deformation stroke, the second permanent magnet and the third permanent magnet simultaneously attract the first permanent magnet to approach, thereby applying a reverse force that gradually increases from small to large to the elastic return member. In the middle to late stages of the deformation stroke, the first permanent magnet is inserted between the second permanent magnet and the third permanent magnet, thereby applying a reverse force that gradually decreases from large to small to the elastic return member.

4. The magnetic release according to claim 3, characterized in that: The first permanent magnet is finally inserted at the center of the second permanent magnet and the third permanent magnet, so that the attraction forces of the second permanent magnet and the third permanent magnet on the first permanent magnet cancel each other out.

5. The magnetic release according to claim 4, characterized in that: The first permanent magnet, the second permanent magnet and the third permanent magnet are sheet-like structures with the same specifications.

6. The magnetic release according to claim 1 or 2, characterized in that: The movement stroke of the armature is linear movement, and the elastic reset member is a tension spring or a compression spring.

7. The magnetic release according to claim 1 or 2, characterized in that: The movement stroke of the armature is swinging, and the elastic reset member is a torsion spring.

8. The magnetic release according to claim 6, characterized in that: The magnetic release also includes an unlocking member, a guide rod and a supporting member, the supporting member is fixedly arranged, a guide hole is opened on the supporting member, the guide rod extends in the guide hole, the armature is fixedly connected to the guide rod, the elastic reset member is a compression spring sleeved on the guide rod, the unlocking member is sleeved on the guide rod and buckled on the compression spring, one end of the compression spring abuts against the unlocking member, and the other end abuts against the supporting member, the first permanent magnet is fixedly connected to the unlocking member, the second permanent magnet and the third permanent magnet are fixedly connected to the supporting member, when the armature moves, it drives the unlocking member to unlock the locking mechanism and compresses the compression spring to make the compression spring produce the deformation stroke, so that the first magnetic suction end fixedly connected to the unlocking member follows the deformation stroke of the elastic reset member.

9. The magnetic release according to claim 1, characterized in that: The distances between the second permanent magnet and the third permanent magnet and the first permanent magnet are adjustable.

10. A circuit breaker, comprising a locking mechanism and a magnetic release, characterized in that: The magnetic release is the magnetic release described in any one of claims 1-9.

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