Magnetic latching relay

Abstract

The invention discloses a magnetic latching relay, and relates to the technical field of relays. In order to solve the problems that the contact opening distance of a conventional relay is insufficient (only 0.8 mm) and the conventional relay is difficult to bear 6000A short-circuit current, the invention designs a symmetrical Z-type contact system. The system comprises two groups of movable reeds which form a Z-shaped structure through a riveting connection sheet. And the armature assembly rotates to drive the two push sheets to drive each group of movable reeds to realize a stroke greater than 3mm, so that an electric gap between the two lead-out sheets is greater than 5.5 mm. When short-circuit large current occurs, reverse repulsive Lorentz force (F2) is generated between the movable contact spring and the connecting sheet, repulsive force (F1) between the movable contact and the static contact is offset, reliable attachment of the contacts is ensured, and explosion under the impact of 6000A short-circuit current is prevented.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of relays, and particularly relates to a magnetic latching relay. BACKGROUND

[0002] As a core load switch of a single-phase intelligent electric energy meter, the magnetic latching relay needs to meet strict electrical safety standards. The State Grid currently proposes two key requirements for the magnetic latching relay used in the single-phase intelligent electric energy meter: Contact opening distance requirement: the electrical gap between the contacts in the off state of the relay must be greater than 5.5 mm to ensure safety isolation.

[0003] Short-circuit carrying capacity: the relay needs to withstand a 6000A short-circuit current impact without failure.

[0004] However, the existing conventional magnetic latching relay has significant defects: Insufficient contact opening distance: the contact opening distance of the conventional product is usually only about 0.8 mm, which is far lower than the 5.5 mm safety distance required by the State Grid, and cannot meet the isolation requirements of the load switch of the electric energy meter.

[0005] Weak short-circuit impact resistance: when a short circuit occurs in the circuit (the current can reach thousands of amperes), a strong repulsive force (denoted as F1) is generated between the moving and static contacts due to the large current. If the repulsive force exceeds the holding force of the magnetic circuit system, the contacts will be forced to separate, causing the short-circuit energy to be released in the gap between the separated contacts, which can cause the relay to explode and the electric energy meter to be damaged, and cannot meet the reliability requirements of a 6000A short-circuit current.

[0006] Therefore, it is urgent to develop a new type of magnetic latching relay structure to simultaneously solve the problems of insufficient contact opening distance and insufficient short-circuit explosion resistance. SUMMARY

[0007] The purpose of the embodiment of the application is to provide a magnetic latching relay, which, through the innovative design of a Z-type symmetrical contact system, can realize a single stroke of >3 mm under the driving of the push piece, so that the electrical gap between the two lead-out ends is >5.5 mm when the relay is off, which meets the safety distance standard of the load switch of the single-phase intelligent electric energy meter of the State Grid, thereby solving at least one of the technical problems involved in the background art.

[0008] In order to solve the above technical problems, the application is implemented as follows: The embodiment of the application provides a magnetic latching relay, which comprises a base, a magnetic circuit assembly, an armature assembly, a contact system and a push piece, the contact system adopts a symmetrical Z-type explosion-proof structure and comprises two groups of identical moving spring piece assemblies, two static contacts, two static contact lead-out pieces respectively connected with the two static contacts and a connecting piece. Each group of moving spring leaf assembly comprises a plurality of laminated moving spring leaves and a moving contact riveted at the end of the moving spring leaf and matched with the static contact; The two groups of moving spring leaf assemblies are fixed at the two ends of the same connecting sheet respectively by riveting, forming a Z-shaped structure, and the connecting sheet is fixed in the base; The armature assembly is rotatably arranged at the side of the magnetic circuit assembly, and the two ends thereof are connected with two push sheets respectively; Each push sheet drives a group of moving spring leaf assemblies, so that the movement stroke of the moving spring leaf assembly is greater than 3mm, and the contact opening distance is greater than 3mm; When the relay is in the open state, the electrical gap between the two static contact lead-out sheets is greater than 5.5mm.

[0009] Optionally, in the moving spring leaf assembly, the current path is: static contact lead-out sheet→static contact→moving contact→moving spring leaf→connecting sheet→another side moving spring leaf→moving contact→static contact→another static contact lead-out sheet, forming a symmetrical current loop.

[0010] Optionally, under the impact of short-circuit current, repulsive Lorentz force is generated between each group of moving spring leaves and the connecting sheet, and the repulsive Lorentz force is opposite to the direction of the repulsive force between the moving contact and the static contact, so as to offset the negative influence of the repulsive force on the contact adhesion.

[0011] Optionally, the push sheet is hinged with the armature assembly, and the rotary motion of the armature assembly is converted into the linear motion of the moving spring leaf assembly through the push sheet.

[0012] Optionally, the static contact is riveted and fixed on the static contact lead-out sheet, and the static contact lead-out sheet is fixed in the base by point gluing.

[0013] Optionally, the magnetic latching relay is applied to a single-phase intelligent electric energy meter and can withstand a short-circuit current impact of 6000A.

[0014] Optionally, each group of moving spring leaf assembly further comprises a pressure spring sheet, and the pressure spring sheet is fixed at the end of the moving spring leaf riveted with the moving contact.

[0015] Optionally, the connecting sheet is fixed in the base by point gluing.

[0016] Compared with the prior art, the present application has the following beneficial effects: (1) The present application realizes a single stroke of >3mm by innovative Z-shaped symmetrical contact system design, so that the electrical gap between the two lead-out ends is >5.5mm when the relay is opened, which meets the safety distance standard of the national grid single-phase intelligent electric energy meter for load switch.

[0017] (2) In the Z-shaped structure of the present application, the moving spring plate assembly and the fixed connecting plate form current loops in opposite directions; when a short-circuit current (such as 6000A) passes through: repulsive force F1 is generated between the moving contact and the stationary contact; and the opposite Lorentz force F2 is generated between the moving spring plate and the connecting plate; the two forces are similar in size and opposite in direction, and cancel each other out, effectively suppressing contact separation, avoiding the release of short-circuit energy in the contact gap to trigger an explosion, and meeting the reliability requirements of 6000A short-circuit current impact.

[0018] (3) The two groups of independent moving spring plates of the present application are synchronously driven by the push piece, improving the stability of the contact movement; the connecting piece is fixed to the base by dispensing, enhancing the overall mechanical strength.

[0019] (4) The present application is designed for the demand of single-phase intelligent electric energy meter load switch, solves the defect of insufficient contact opening distance (only 0.8mm) of traditional magnetic latching relay, and can directly replace the existing products. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor. Figure 1 The overall structure diagram of the magnetic latching relay provided by the present application is shown in the figure; Figure 2 The assembly structure diagram of the contact system provided by the present application is shown in the figure; Figure 3 The assembly structure diagram of the magnetic circuit assembly and the armature assembly provided by the present application is shown in the figure; Figure 4 The current flow direction diagram provided by the present application is shown in the figure; Figure 5 The action diagram of the Lorentz force and the repulsive force of the contact system provided by the present application is shown in the figure. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings of the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0022] The terms "first", "second", and the like in the description and in the claims of the present application are used for distinguishing between similar objects and are not necessarily used to describe a particular sequential or chronological order. It is to be understood that the use of such terms as "first", "second", and the like, if they are used in the specification, is merely to distinguish between two separate and distinct structures, implementations, and the like, and not a sequence or order of one developing before the other. Such terms unless specifically so stated, are not designed to require or infer any such sequence or order. It is also to be understood that the use of the singular includes the plural unless specifically stated otherwise. It is also to be understood that the use of "and / or" means that the items so conjoined are to be taken individually as well as in the conjunctive sense, and that the conjunctive sense is to be understood as applied individually to each item conjunctive. It is also to be understood that the use of "and / or" is not intended to limit the items to a single class or group.

[0023] Referring to Figure 1 As shown in the drawings, the magnetic latching relay provided by the embodiments of the present application comprises a base 1, a magnetic circuit assembly 2, an armature assembly 3, a contact system 4 and a push piece 5 assembled in the base 1. The magnetic circuit assembly 2 drives the armature assembly 3 to rotate, thereby driving the contact system 4 to move through the push piece 5.

[0024] Further referring to Figure 3 As shown in the drawings, the magnetic circuit assembly 2 comprises a coil former 21, a winding coil 22 wound on the coil former 21, an iron core 23 assembled in the coil former 21, yokes 24 arranged at both ends of the iron core 23 and coil lead pins 25 connected to the winding coil 22.

[0025] The armature assembly 3 comprises a plastic main body 31, an armature 32 and a permanent magnet 33 assembled in the plastic main body 31.

[0026] The magnetic latching relay further comprises a fixing frame 6 fixed to the base 1, and the plastic main body 31 is rotatably assembled in the fixing frame 6.

[0027] Further referring to Figure 2 As shown in the drawings, the contact system 4 adopts a symmetrical Z-shaped anti-explosion structure, which comprises two groups of identical moving spring piece assemblies 41, two static contacts 42, two static contact lead-out pieces 43 respectively connected to the two static contacts 42 and a connecting piece 44.

[0028] Each group of moving spring piece assemblies 41 comprises a plurality of moving spring pieces 411 stacked together and a moving contact 412 riveted at the end of the moving spring piece 411 and matched with the static contact 42.

[0029] The two groups of moving spring piece assemblies 41 are respectively fixed at both ends of the same connecting piece 44 by riveting to form a Z-shaped structure, and the connecting piece 44 is fixed in the base 1. Specifically, the connecting piece 44 is fixed in the base 1 by dispensing.

[0030] The armature assembly 3 is rotatably arranged at the side of the magnetic circuit assembly 2, and two ends thereof are connected to two push pieces 5 respectively, and two groups of independent moving spring pieces are synchronously driven by the push pieces 5 to stabilize the movement of the contact.

[0031] Each push piece 5 drives a group of moving spring piece assemblies 41, so that the movement stroke of the moving spring piece assemblies 41 is greater than 3 mm, the contact opening distance is greater than 3 mm, the electrical gap between the two static contact lead-out pieces 43 is greater than 5.5 mm when the relay is in the off state, thereby meeting the safety distance standard of the load switch of the single-phase intelligent electric energy meter of the State Grid.

[0032] Referring to FIG. 1 in detail, Figure 4 As shown in the figure, in the moving spring piece assembly 41, the current path is: static contact lead-out piece 43→static contact 42→moving contact 412→moving spring piece 411→connecting piece 44→another moving spring piece 411→moving contact 412→static contact 42→another static contact lead-out piece 43, forming a symmetrical current loop.

[0033] Referring to FIG. 2 in detail, Figure 5 As shown in the figure, under the impact of short-circuit current, repulsive Lorentz force F2 is generated between each group of moving spring piece assemblies 41 and the connecting piece 44, the direction of the Lorentz force F2 is opposite to that of the repulsive force F1 between the moving contact 412 and the static contact 42, and the Lorentz force F2 offsets the negative effect of the repulsive force F1 on the contact adhesion. The two forces are similar in size and opposite in direction, and offset each other, effectively inhibiting the separation of the contacts and avoiding explosion caused by the release of short-circuit energy in the contact gap, meeting the reliability requirement of 6000A short-circuit current impact.

[0034] The push piece 5 is hinged to the armature assembly 3, and the rotational movement of the armature assembly 3 is converted into the linear movement of the moving spring piece assembly 41 through the push piece 5.

[0035] The static contact 42 is riveted and fixed on the static contact lead-out piece 43, and the static contact lead-out piece 43 is fixed on the base 1 by point gluing.

[0036] The magnetic latching relay is applied to a single-phase intelligent electric energy meter and can withstand 6000A short-circuit current impact.

[0037] Each group of moving spring piece assemblies 41 further comprises a pressure spring 45, and the pressure spring 45 is fixed at the end of the moving spring piece 411 on which the moving contact 412 is riveted.

[0038] It has to be understood that, in the present document, the terms "comprising", "including", or any other variant thereof, are intended to cover a non-exclusive inclusion, such that processes, methods, articles, or apparatuses that comprise a list of elements are not limited to those elements, but can include other elements not expressly listed or inherent to such processes, methods, articles, or apparatuses. Without further limitation, an element preceded by "comprises a" does not, without more constraints, foreclose the existence of additional identical elements in the process, method, article, or apparatus that comprises the recited element.

[0039] Furthermore, it is indicated that the scope of the methods and systems of the embodiments of the present application is not limited to performing functions in the order discussed or illustrated, and includes performing functions in a substantially simultaneous manner or in the reverse order of those described, for example, the methods described can be performed in other than the order described, and additional, fewer, or different steps can be added, omitted, or combined, and the features described with respect to some examples can be combined in other examples.

[0040] The embodiments of the present application described above are merely illustrative, and are not intended to limit the present application, and the present application is not limited to the specific embodiments described above, and the specific embodiments described above are merely illustrative, but are not restrictive, and a person of ordinary skill in the art can make many forms under the inspiration of the present application without departing from the purpose of the present application and the scope protected by the claims, and all of them belong to the protection of the present application.

Claims

1. A magnetic latching relay comprising a base, a magnetic circuit assembly, an armature assembly, a contact system, and a push piece, characterized in that: The contact system adopts a symmetrical Z-type explosion-proof structure, including two sets of identical dynamic spring components, two static contacts, two static contact lead-out plates connected to the two static contacts respectively, and a connecting plate; Each set of dynamic spring assembly includes a plurality of stacked dynamic springs and a dynamic contact riveted to the ends of the dynamic springs and cooperating with the static contact; The two sets of dynamic spring components are fixed to the two ends of the same connecting piece by riveting to form a Z-shaped structure. The connecting piece is fixed in the base. The armature assembly is rotatably arranged on the side of the magnetic circuit assembly, and its two ends are respectively connected to two push pieces; Each push piece drives a corresponding set of dynamic spring components, so that the movement stroke of the dynamic spring components is greater than 3mm, and the contact opening distance is greater than 3mm; When the relay is in the disconnected state, the electrical gap between the two static contact lead pieces is greater than 5.5mm.

2. The magnetic latching relay according to claim 1, wherein: In the movable spring assembly, the current path is: static contact lead-out piece → static contact → movable contact → movable spring → connecting piece → other side movable spring → movable contact → static contact → other static contact lead-out piece, forming a symmetrical current loop.

3. The magnetic latching relay according to claim 2, wherein: Under the impact of short-circuit current, a repulsive Lorentz force is generated between each set of moving springs and connecting pieces. The direction of this Lorentz force is opposite to the repulsive force between the moving contact and the static contact, offsetting the negative impact of the repulsive force on contact contact.

4. The magnetic latching relay according to claim 1, wherein: The push piece is hinged to the armature assembly, and the rotational motion of the armature assembly is converted into the linear motion of the movable spring assembly through the push piece.

5. The magnetic latching relay according to claim 1, wherein: The static contact is fixed on the static contact lead-out piece by riveting, and the static contact lead-out piece is fixed to the base by glue dispensing.

6. The magnetic latching relay according to claim 1, wherein: The magnetic latching relay is applied to a single-phase smart electric energy meter and can withstand a 6000A short-circuit current impact.

7. The magnetic latching relay according to claim 1, wherein: Each group of dynamic spring leaf assemblies further includes a pressure spring leaf fixed to the end of the dynamic spring leaf riveted with the dynamic contact.

8. The magnetic latching relay according to claim 1, wherein: The connecting piece is fixed in the base by glue.

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