Electromagnetic relay

Abstract

Provided in the present application is an electromagnetic relay, comprising a relay body and a lead-out plate, wherein the lead-out plate is connected to a reed of a contact part of the relay body and extends to the outside of a housing of the relay body, the part of the lead-out plate that is located inside the housing of the relay body is defined as an internal lead-out part, and the part of the lead-out plate that is located outside the housing of the relay body is an external lead-out part. The electromagnetic relay further comprises a magnetically-conductive magnetic shielding member, the magnetic shielding member being wrapped around the external lead-out part located outside the housing of the relay body. After a current enters the external lead-out part, a generated magnetic field is concentrated on the magnetic shielding member; in this way, the influence of an external magnetic field generated by an external assembly on the internal magnetic field of the relay can be effectively reduced, so as to ensure the reliability of the electromagnetic relay.

Description

An electromagnetic relay

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the Patent Office of China on February 7, 2024, with application number CN202420288362.4 and invention name “An Electromagnetic Relay”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the technical field of electronic control devices, and in particular to an electromagnetic relay. Background Art

[0004] An electromagnetic relay is an electronic control device with a control system (also known as an input circuit) and a controlled system (also known as an output circuit). It is commonly used in automatic control circuits. It is essentially an "automatic switch" that uses a smaller current and lower voltage to control a larger current and higher voltage. Therefore, it plays a role in automatic regulation, safety protection, and circuit conversion in circuits.

[0005] As shown in Figure 1, an electromagnetic relay generally includes a relay body 10 and a lead-out plate 20. The relay body 10 includes a housing 11 and a magnetic circuit portion and a contact portion disposed within the housing 11. The lead-out plate 20 connects to the spring of the contact portion of the relay body 10 and extends outside the housing 11 of the relay body 10. When operating under high current (e.g., 4.5kA short-circuit resistance), this affects the rotation of the armature, causing the relay to fail. Failure analysis revealed that the magnetic field generated by the wires drawn from the test equipment connected to the relay and the current connected to the relay's line sequence are different in direction. When power is applied, the magnetic field generated by the external component (including the lead-out plate 20 located outside the relay body 10) passes through the relay's magnetic circuit and the armature portion. This magnetic field, upon entering the relay, increases the magnetic field of the magnetic circuit core. The polarity of the magnetic field of the permanent magnet within the relay is opposite to that generated by the external component when current is applied, thereby offsetting the magnetic field strength of the internal permanent magnet and weakening the holding force at the junction of the armature portion and the yoke. When a large current passes through, the lead-out plate generates a Lorentz force that forces the reed to deform upward in a C-bend. When the holding force decreases to a certain level, the connecting rod mechanism on the armature part cannot support the contact part. At this time, the Lorentz force generated by the lead-out plate when a large current passes through is greater than the holding force of the relay. The state of the relay armature cannot be maintained and changes, causing the contacts to bounce and splash.

[0006] Overview

[0007] The embodiments of this application disclose the following technical solutions:

[0008] In a first aspect, an embodiment of the present application provides an electromagnetic relay, comprising:

[0009] A relay body, a lead-out piece, and a magnetically conductive magnetic shield. The lead-out piece is connected to the spring piece of the contact portion of the relay body and extends outside the housing of the relay body. The lead-out piece portion located inside the housing of the relay body is defined as the internal lead-out portion, and the lead-out piece portion located outside the housing of the relay body is defined as the external lead-out portion. The magnetic shield is wrapped around the external lead-out portion located outside the housing of the relay body.

[0010] In some embodiments of the present application, the lead-out piece includes a first lead-out piece and a second lead-out piece, the first end of the first lead-out piece is connected to the spring of the contact part of the relay body, and the second end thereof extends outside the housing of the relay body; the second lead-out piece is located outside the housing of the relay body and connected to the second end of the first lead-out piece; the second end of the first lead-out piece and the second lead-out piece constitute an external lead-out part; the magnetic shielding member is wrapped around the second lead-out piece.

[0011] In some embodiments of the present application, the magnetic shielding member surrounds the external lead-out portion and is perpendicular to the iron core in the relay body.

[0012] In some embodiments of the present application, the second lead-out piece includes a long straight section and connecting sections connected at both ends of the long straight section, wherein one connecting section is connected to the second end of the first lead-out piece; the other connecting section is used for an external circuit; and the magnetic shielding member is wrapped around the long straight section of the second lead-out piece.

[0013] In some embodiments of the present application, the connecting segment is arranged perpendicular to the long straight segment, and the magnetic shielding member further extends to the inner side of the connecting segment.

[0014] In some embodiments of the present application, the magnetic shield further surrounds the connection between the first lead-out piece and the second lead-out piece.

[0015] In some embodiments of the present application, the magnetic shield is completely wrapped around the outer circumference of the external lead-out portion.

[0016] In some embodiments of the present application, the magnetic shield covers the upper surface, the lower surface and the side of the external lead-out portion facing the relay body.

[0017] In some embodiments of the present application, the magnetic shield extends along a direction away from the relay body to form an elongated side on a side portion covering the lower surface of the external lead-out portion.

[0018] In some embodiments of the present application, the magnetic shielding member is a shielding iron member.

[0019] The technical solution provided by this application has the following beneficial effects:

[0020] A magnetic shielding member with magnetic conductivity is used to wrap around the external lead-out part. When current enters the external lead-out part, the generated magnetic field is concentrated on the magnetic shielding member. In this way, the influence of the external magnetic field generated by the external component on the internal magnetic field of the relay can be effectively reduced, thereby ensuring the reliability of the electromagnetic relay.

[0021] Moreover, this solution directly sets up a magnetic shielding member to shield the interference source, which has a simple structure and significant effect.

[0022] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0024] FIG1 is a schematic structural diagram of an electromagnetic relay provided by the related art;

[0025] FIG2 is a schematic diagram of the three-dimensional structure of an electromagnetic relay provided in an embodiment of the present application;

[0026] FIG3 is a side view schematic diagram of the structure of a first electromagnetic relay provided in an embodiment of the present application;

[0027] FIG4 is a side view schematic diagram of the structure of a second electromagnetic relay provided in an embodiment of the present application;

[0028] FIG5 is a schematic structural diagram of a magnetic shielding member provided in an embodiment of the present application.

[0029] Figure numerals: 10: relay body, 11: housing, 20: lead piece, 21: dynamic spring lead piece, 211: first lead piece, 212: second lead piece, 213: long straight section, 214: first connecting section, 215: second connecting section, 22: static spring lead piece, 30: magnetic shielding part, 31: extended side, 32: protrusion. Specific embodiments

[0030] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0031] In the accompanying drawings, the thickness of regions and layers may be exaggerated for clarity. The same reference numerals in the drawings represent the same or similar structures, and their detailed descriptions will be omitted. In addition, the accompanying drawings are only schematic illustrations of the present application and are not necessarily drawn to scale.

[0032] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0033] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "multiple" means two or more, unless otherwise clearly and specifically defined. "Several" means one or more, unless otherwise clearly and specifically defined.

[0034] In the description of this application, it should be understood that the terms "up", "down", "front", "back", "left", "right", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limitations on this application.

[0035] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0036] In order to solve the technical problems existing in the structure shown in FIG1 , an embodiment of the present application provides an electromagnetic relay.

[0037] The electromagnetic relay provided in this application is further described below with reference to the accompanying drawings and specific implementations.

[0038] In one possible implementation, the first electromagnetic relay provided in the embodiment of the present application is improved based on the structure shown in FIG1 for ease of explanation. The electromagnetic relay includes a relay body 10 and a lead piece 20. Specifically, the relay body 10 includes a housing 11, a magnetic circuit portion disposed within the housing 11, and a contact portion. The contact portion includes a movable spring and a static spring. The armature of the magnetic circuit portion is connected to the movable spring via a push-clip to drive the movable spring.

[0039] The lead-out tabs 20 connect to the spring tabs of the contact portion of the relay body 10 and extend outside the housing 11 of the relay body 10. Specifically, the dynamic spring and static spring of the contact portion are each connected to a set of lead-out tabs 20; the lead-out tab 20 connected to the dynamic spring is defined as the dynamic spring lead-out tab 21, and the lead-out tab 20 connected to the static spring is defined as the static spring lead-out tab 22. Specifically, as shown in Figure 1, the static spring end (i.e., the static spring lead-out tab 22) is located away from the permanent magnet in the relay, and its bend line is close to the iron core (i.e., the bend line of the static spring lead-out tab 22 near the mounting hole is close to the central axis of the iron core in the relay). When external current is applied, the magnetic field generated by the static spring lead-out tab 22 outside the housing 11 is parallel to the magnetic field of the permanent magnet in the housing 11, minimizing the magnetic field effect. However, the dynamic spring lead-out tab 21 has a portion arranged perpendicular to the iron core. The external magnetic field generated by this portion perpendicularly enters the magnetic field of the permanent magnet in the housing 11, causing interference and a greater impact. Therefore, in the embodiment of the present application, the improvement is mainly made in the movable spring lead-out piece 21 , that is, the present solution is developed with the movable spring lead-out piece 21 .

[0040] Continuing with Figures 2 to 5 , the lead-out portion located within the housing 11 of the relay body 10 is defined as the internal lead-out portion, while the lead-out portion located outside the housing 11 of the relay body 10 is defined as the external lead-out portion. In this specific embodiment, the dynamic spring lead-out piece 21 includes a first lead-out piece 211 and a second lead-out piece 212. The first lead-out piece 211 has a first end connected to the spring (i.e., the dynamic spring) of the contact portion of the relay body 10, and its second end extends outside the housing 11 of the relay body 10. The second lead-out piece 212 is located outside the housing 11 of the relay body 10 and connected to the second end of the first lead-out piece 211. Specifically, the second lead-out piece 212 serves as a welding piece welded to the second end of the first lead-out piece 211. The second end of the first lead-out piece 211 and the second lead-out piece 212 constitute the external lead-out portion. The second lead-out piece 212 is positioned perpendicular to the iron core within the relay body. The electromagnetic relay also includes a magnetic shield 30 wrapped around the second lead-out piece 212.

[0041] Specifically, in the embodiment of the present application, the second lead-out piece 212 includes a long straight section 213 and connecting sections connected at both ends of the long straight section 213, namely a first connecting section 214 and a second connecting section 215. The first connecting section 214 connects to the second end of the first lead-out piece 211; the second connecting section 215 is used for external circuit connection. The configuration of the dynamic spring lead-out piece 21 is such that failure analysis indicates that the external magnetic field generated by the long straight section 213 of the second lead-out piece 212 has the greatest impact on the relay body. Therefore, in the embodiment of the present application, the magnetic shield 30 is wrapped only around the long straight section 213 of the second lead-out piece 212. This significantly reduces the impact of the external magnetic field generated by the external component on the internal magnetic field of the relay, while also simplifying the structural configuration.

[0042] Specifically, the first connecting section 214 and the second connecting section 215 are both arranged perpendicular to the long straight section 213, and the magnetic shielding member 30 also extends to the inner side of the first connecting section 214 and the second connecting section 215 to form a protrusion 32. The protrusion 32 is provided to be engaged with the connecting sections at both ends of the second lead-out piece 212. Of course, in other embodiments, the protrusion 32 structure may not be required, and the magnetic shielding member 30 and the second lead-out piece 212 can also be fixed by riveting or welding.

[0043] In the embodiment of the present application, the magnetic shielding member 30 covers the upper surface, the lower surface and the side facing the relay body 10 of the external lead-out portion (the long straight section 213 in the embodiment of the present application), forming a U-shaped covering shell; such a setting, on the basis of shielding the external magnetic field generated by the long straight section 213 of the second lead-out piece 212, makes the disassembly and assembly of the magnetic shielding member easier.

[0044] Furthermore, the magnetic shielding member 30 extends on the side of the lower surface covering the long straight section 213 in the direction away from the relay body 10 to form an extended side 31. This arrangement lengthens the conduction path of the magnetic field generated by the long straight section 213, and lengthens in the direction away from the relay body. That is, when the magnetic field of the long straight section 213 is generated, the magnetized shielding member lengthens the magnetic field loop through the extended side 31, increases the magnetic resistance and reduces the external magnetic field from entering the housing 11; in this way, the impact on the internal magnetic field of the relay is smaller and the improvement effect is better.

[0045] Specifically, in the embodiment of the present application, the magnetic shielding member 30 can be a shielding iron member, which has low cost and good magnetic conductivity. In addition, in other embodiments, other magnetically conductive materials can also be used instead.

[0046] At the same time, the thicker the magnetic shielding member 30 is, the stronger the magnetic field concentration effect is, the weaker the peripheral magnetic field is, and the smaller the impact on the internal magnetic field of the relay is.

[0047] In actual use, the length of the magnetic shielding member 30 is determined to meet actual installation requirements, and the longer the better; it should be as long as possible and equal to the long straight section 213 of the second lead-out piece 212 .

[0048] In another possible implementation, the second electromagnetic relay provided in the present application has a substantially similar structure to the first electromagnetic relay described above, except that in this embodiment, the magnetic shield 30 also surrounds the junction between the first lead-out piece 211 and the second lead-out piece 212, namely, the weld between the first connecting section 214 and the second end of the first lead-out piece 211. This arrangement can also reduce the impact of the magnetic field generated at this location on the internal magnetic field of the relay.

[0049] In another possible implementation, the third electromagnetic relay provided in the embodiment of the present application has a structure roughly the same as that of the first electromagnetic relay described above, except that: in this embodiment, the dynamic spring lead-out piece 21 is an integrally connected structure, that is, the first lead-out piece 211 and the second lead-out piece 212 are integrally connected, and at the same time, the magnetic shielding member 30 is completely wrapped around the outer peripheral side of the external lead-out portion of the dynamic spring lead-out piece 21.

[0050] In another possible implementation, the fourth electromagnetic relay provided in the embodiment of the present application has a structure roughly the same as the first electromagnetic relay described above, except that: in addition to wrapping the magnetic shielding member 30 around the second lead-out piece 212 of the movable spring lead-out piece 21, if the external lead-out portion of the static spring lead-out piece 22 also has a portion perpendicular to the iron core in the relay body, the magnetic shielding member 30 is also wrapped around the external lead-out portion of the static spring lead-out piece 22.

[0051] The above embodiments are improvements based on the electromagnetic relay shown in FIG1 . Of course, in other embodiments, the structure of the electromagnetic relay may differ from that shown in FIG1 . Regardless, as long as the magnetic shield 30 is wrapped around the external lead portion outside the housing 11 of the relay body 10 to reduce the impact of the external magnetic field generated by the external components on the internal magnetic field of the relay, it can be used.

[0052] References herein to "one embodiment," "an embodiment," or "one or more embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present application. Furthermore, please note that instances of the phrase "in one embodiment" do not necessarily all refer to the same embodiment.

[0053] In the description provided herein, a large number of specific details are described. However, it is understood that the embodiments of the present application can be practiced without these specific details. In some instances, well-known methods, structures, and techniques are not shown in detail so as not to obscure the understanding of this description.

[0054] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An electromagnetic relay comprising a relay body and a lead piece, wherein the lead piece is connected to a spring piece of a contact portion of the relay body and extends outside the housing of the relay body, wherein the lead piece portion located inside the housing of the relay body is defined as an internal lead piece, and the lead piece portion located outside the housing of the relay body is defined as an external lead piece; wherein: The electromagnetic relay further includes a magnetic shielding member that is magnetically conductive and is wrapped around an external lead-out portion located outside the housing of the relay body.

2. The electromagnetic relay according to claim 1, wherein: The lead-out piece includes a first lead-out piece and a second lead-out piece. The first end of the first lead-out piece is connected to the spring of the contact part of the relay body, and the second end of the first lead-out piece extends outside the housing of the relay body. The second lead-out piece is located outside the housing of the relay body and connected to the second end of the first lead-out piece. The second end of the first lead-out piece and the second lead-out piece constitute an external lead-out portion. The magnetic shield is wrapped around the second lead-out piece.

3. The electromagnetic relay according to claim 2, wherein: The magnetic shield surrounds the external lead-out portion and is perpendicular to the iron core in the relay body.

4. The electromagnetic relay according to claim 3, wherein: The second lead-out piece includes a long straight section and connecting sections connected at both ends of the long straight section, one connecting section is connected to the second end of the first lead-out piece; the other connecting section is used for external circuits; the magnetic shielding component is wrapped around the long straight section of the second lead-out piece.

5. The electromagnetic relay according to claim 4, wherein: The connecting section is arranged perpendicular to the long straight section, and the magnetic shielding component also extends to the inner side of the connecting section.

6. The electromagnetic relay according to claim 4, wherein: The magnetic shield also surrounds the connection between the first lead-out piece and the second lead-out piece.

7. The electromagnetic relay according to claim 1 or 2, wherein: The magnetic shield completely surrounds the outer circumference of the external lead-out portion.

8. The electromagnetic relay according to claim 1 or 2, wherein: The magnetic shield covers the upper surface, the lower surface and the side of the external lead-out portion facing the relay body.

9. The electromagnetic relay according to claim 8, wherein: The magnetic shielding member extends in a direction away from the relay body to form an elongated side on a side portion covering a lower surface of the external lead-out portion.

10. The electromagnetic relay according to claim 1 or 2, wherein: The magnetic shielding part is a shielding iron part.

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