ELECTROMAGNETIC RELAY

Abstract

An electromagnetic relay comprising: a magnetic circuit system and a contact system, wherein the magnetic circuit system comprises an enamel wire (1), a coil (2), a yoke iron (3), an iron core (4), and an armature (5); the enamel wire (1) is wound around the coil (2) to form a coil structure; the iron core (4) is inserted through a through-hole of the coil (2); wherein the yoke iron (3) comprises a first part (31) and a second part (32) formed in an approximately L-shaped structure; the first part (31) of the yoke iron (3) is connected to one end of the iron core (4); the second part (32) of the yoke iron (3) is arranged on one side of a winding window of the coil (2); wherein the contact system comprises a movable spring (6), a fixed spring (7), a movable contact (60) cooperating with the movable spring (6), and a fixed contact (70) cooperating with the fixed spring (7); the fixed spring (7) is mounted on the coil (2);the fixed spring (7) is provided with a fixed spring guide pin (71); the movable spring (6) is bent in a substantially L-shaped form and comprises a first bent portion (61) and a second bent portion (62); the first bent portion (61) of the movable spring (6) is fixed to the second part (32) of the yoke iron (3); the second bent portion (62) of the movable spring (6) is fixed to the armature (5), and the armature (5) abuts against a cutting edge of the yoke iron (3) corresponding to the other end of the iron core (4); and the first bent portion (61) of the movable spring (6) is provided with a movable spring extension arm (63) extending toward the end piece (321) of the second part (32) of the yoke iron (3); characterized in that an end piece (321) of the second part (32) of the yoke iron (3) is provided with a guide pin of the yoke iron (3) which is parallel to an axis of the coil (2);the extension arm (63) of the movable spring is connected to the end piece (321) of the second part (32) of the yoke iron (3) to achieve the electrical connection between the movable spring (6) and the guide pin (322) of the yoke iron (3); a first through-hole (323) is formed on the yoke iron (3) and at a position near the end piece (321) of the second part (32) of the yoke iron (3); and the second bending portion (62) of the movable spring (6) is guided through the first through-hole (323) and is fixed to the armature (5);

Description

CROSS REFERENCEThis application is based on and claims priority from Chinese Patent Application No. 20180785048.6, filed on Jul. 17, 2018, the entire contents of which are incorporated herein by reference.TECHNICAL FIELDThe present disclosure relates to the technical field of relays, and more particularly, to an electromagnetic relay applied under a high current load and of which a movable spring is provided with an extension arm structure.PRIOR ARTAs electromechanical components, electromagnetic relays are widely used in a wide variety of electromechanical devices. The electromagnetic relay generally comprises a contact system, a magnetic circuit system. The contact system comprises a fixed spring, a fixed contact, a movable spring, a movable contact. The magnetic circuit system includes a coil, a yoke iron, an iron core, and an armature. The contact system and the magnetic circuit system are combined by riveting or welding together the movable spring, the armature and the yoke iron. In the contact system, a conductive loop is generally formed by configuring the movable spring and the fixed spring to have guide pins, respectively. A conventional spring is designed to have guide pins on a spring body. The movable spring is generally thin. When the movable spring is applied at a high current load, when a part of the spring is generally used as the guide pin, a part of the guide pin needs to be coated in order to increase a current carrying area of the spring and to avoid a high current density of the spring. In this way, the difficulty of manufacturing molds increases. In particular, springs are generally bent, which further increases the difficulty of coating the guide pins, which complicates implementation in the art. In the prior art, an electromagnetic relay applied at a high current load, the conductive leading ends of the movable spring are directly arranged on the yoke iron to achieve miniaturization and a compact structure. In this way, the conductor loop of the contact system comprises the yoke iron, the movable spring, contacts and a fixed spring. The advantage of arranging the guide pin of the movable spring on the yoke iron is that the structure is relatively simple and the technology is easy to realize, and the shape of the structure of the spring is further simplified. Further, however, this method of arranging the guide pins of the movable spring on the yoke iron has disadvantages. Since the material of the movable spring is a copper alloy material and the main material of the yoke iron is pure iron, the electrical conductivity of the iron is far below that of the copper, there are disadvantages of low conductivity and high temperature. That is, a temperature rise of the conductor loop is higher than that of the conductor loop formed by the guide pin of the movable spring and the guide pin of the fixed spring. Especially, at a high load current, the performance of the electromagnetic relay deteriorates when the temperature rise is too high, and too high a temperature rise of circuit boards results in adverse effects. An electromagnetic relay known from the prior art is disclosed, for example, in the publication CN 1 06 206 166 A. This is an electromagnetic relay having an injection molded yoke, a movable spring and an iron core coil. The document CN 2 02 695 312 U, on the other hand, discloses a small-sized high-current PCB relay for automobiles comprising a base part, a magnetic circuit part, a movable spring armature part and a housing.SUMMARY OF THE INVENTIONAn object of the present disclosure is to solve defects of the related art and to provide an electromagnetic relay. By structural improvement, a temperature rise of a conductor loop of a contact system can be effectively reduced. The electromagnetic relay is provided with the following features: small temperature rise of the conductor loop, simple structure, small volume, good mounting property and good workability.The technical solution provided by the present disclosure to achieve its technical object is as follows: an electromagnetic relay including a magnetic circuit system and a contact system, wherein the magnetic circuit system includes a enameled wire, a coil, a yoke iron, an iron core, and an armature; the enameled wire is wound around the coil to form a coil structure; the iron core is inserted through a through hole of the coil; wherein the yoke iron includes a first part and a second part formed in an approximately L-shaped structure; the first part of the yoke is connected to an end of the iron core; the second part of the yoke iron is disposed at a winding window side of the coil; the contact system comprises a movable spring, a fixed spring, a movable contact cooperating with the movable spring, and a fixed contact cooperating with the fixed spring; the fixed spring is mounted on the coil; the fixed spring is provided with a fixed spring guide pin; the movable spring is bent in a substantially L-shaped shape and comprises a first bent portion and a second bent portion; the first bent portion of the movable spring is fixed to the second portion of the yoke iron; the second bent portion of the movable spring is fixed to the armature and the armature abuts a blade of the yoke iron corresponding to the other end of the iron core; wherein an end portion of the second portion of the yoke iron is provided with a guide pin of the yoke iron parallel to an axis of the coil; the first bending portion of the movable spring is provided with an extension arm of the movable spring extending toward the end portion of the second part of the yoke iron; and the extension arm of the movable spring is connected to the end portion of the surface of the second part of the yoke iron to achieve the electrical connection between the movable spring and the guide pin of the yoke iron.An end part of the end part of the first bending portion of the movable spring is fixed to the second part of the yoke iron; the number of extension arms of the movable spring is two; and the two extension arms of the movable spring, each formed by the end part of the end part of the first bending portion of the movable spring, extend toward the end part of the second part of the yoke iron.A first through hole is formed on the yoke iron and at a position near the end portion of the second part of the yoke iron; the second bent portion of the movable spring is passed through the first through hole and fixed to the armature; and the two extending arms of the movable spring extend along the parts of the yoke iron at two sides of the first through hole, respectively.The first through hole of the yoke iron is shaped as a rectangular shape; a side wall of the first through hole away from the end portion of the second part of the yoke iron is the cutting edge of the yoke iron.The guide pin of the yoke iron is provided at the center of the end portion of the second part of the yoke iron.The movable spring is provided with a second through hole having a strip shape; the second through hole first extends in the direction approximately parallel to the first bent portion, and then bent to extend in the direction approximately parallel to the second bent portion of the movable spring.Further, an insulating plate is disposed between the second part of the yoke iron and a winding window of the coil to increase a creepage distance between the enameled wire of the coil at the position corresponding to the winding window and the yoke iron.The insulating plate is further coated on both sides of the second part of the yoke iron in the width direction thereof.The electromagnetic relay further includes a bottom plate; the guide pin of the yoke iron at the end portion of the second part of the yoke iron is inserted into the bottom plate component; the bottom plate component is joined to the coil by clamping.Compared with the prior art, the advantageous effects of the present disclosure are as follows:1. The present disclosure provides that an end portion of the second part of the yoke iron is provided with a yoke iron guide pin that is parallel to an axis of the coil; the first bending portion of the movable spring is provided with an extension arm of the movable spring that extends toward the end portion of the second part of the yoke iron; and the extension arm of the movable spring is connected to the end portion of the surface of the second part of the yoke iron to achieve the electrical connection between the movable spring and the guide pin of the yoke iron. This structure of the present disclosure simplifies the shape of the structure of the movable spring by disposing the leading-out portions of the movable spring on the yoke iron, which is advantageous for the miniaturization and compactness of the product. The present disclosure establishes the electrical connection between the movable spring and the guide pin of the yoke iron by providing the extension arms of the movable spring to the movable spring, a conductive path of the yoke iron can be shortened, the impedance of a conductive loop is decreased, and the temperature rise of the conductive loop is decreased, so that the electromagnetic relay in the present disclosure has characteristics of: a small temperature rise of the conductive loop, a simple structure and a small volume, a good mounting property, and a good workability.2. The present disclosure provides that the lead-out portion of the movable spring is provided on the yoke iron, and the insulating plate is further disposed between the surface of the second part of the yoke iron and a winding window of the coil. The creepage distance between the enameled wire of the coil at the position corresponding to the winding window and the yoke iron is increased using the insulating plate. That is, the creepage distance between a load circuit and a coil circuit is increased, so that a required withstand voltage of the product can be improved.The present disclosure will be described in detail below with reference to the accompanying drawings and embodiments. However, an electromagnetic relay of the present disclosure is not limited to embodiments.BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1 is a schematic structural diagram of the present disclosure; FIG. 2 is a schematic structural diagram of the present disclosure (showing a state in which the structure in FIG. 1 is rotated at an angle); FIG. 3 is a schematic structural diagram of a magnetic circuit system of the present disclosure; FIG. 4 is a schematic structural diagram of a movable spring of the present disclosure; FIG. 5 is an installation diagram of an insulating plate of the present disclosure.DETAILED DESCRIPTIONEmbodimentReferring to FIGS. 1 to 5, an electromagnetic relay of the present disclosure includes a magnetic circuit system and a contact system. The magnetic circuit system includes a enamelled wire 1, a coil 2, a yoke iron 3, an iron core 4, and an armature 5. the enamelled wire 1 is wound around the coil 2 to form a coil structure. The iron core 4 is inserted through a through hole of the coil 2. The yoke iron 3 includes a first part 31 and a second part 32 formed in an approximately L-shaped structure. The first part 31 of the yoke iron 3 is connected to one end of the iron core 4. The second part 32 of the yoke iron 3 is disposed on a side of a winding window of the coil 2. The contact system comprises a movable spring 6, a fixed spring 7, a movable contact 60 cooperating with the movable spring 6, and a fixed contact 70 cooperating with the fixed spring 7. In one embodiment, the movable contact 60 is fixed to the movable spring 6. A fixed contact 70 is fixed to the fixed spring 7. The position of the movable contact 60 on the movable spring 6 corresponds to the position of the fixed contact 70 on the fixed spring 7. The fixed spring 7 is provided with a fixed spring guide pin 71. The movable spring 6 is bent in a substantially L-shaped shape and further includes a first bent portion 61 and a second bent portion 62. The second bent portion 62 of the movable spring 6 is fixed to the armature 5, and the armature 5 abuts on a blade of the yoke iron 3 corresponding to the other end of the iron core 4. An end portion 321 of the second part 32 of the yoke iron 3 is provided with a guide pin 322 of the yoke iron which is parallel to an axis of the coil. The first bent portion 61 of the movable spring 6 is provided with a movable spring extending arm 63 which extends toward the end portion 321 of the second part 32 of the yoke iron 3. And, the movable spring extension arm 63 is connected (by riveting or welding, etc.) to the end piece 321 of the second part 32 of the yoke iron 3 to achieve the electrical connection between the movable spring 6 and the guide pin 322 of the yoke iron.As shown in FIG. 4, in the present embodiment, an end part 611 of the end part of the first bent portion 61 of the movable spring 6 is fixed to the second part 32 of the yoke iron 3. The number of the movable spring extending arms 63 is two. The two movable spring extending arms 63 are each formed by the end part 611 of the end part of the first bending portion 61 of the movable spring 6, extend toward the end part 321 of the second part of the yoke iron 3, that is, as shown in FIG. 4, the two movable spring extending arms 63 are located in the same plane as the end part 611 of the end part of the first bending portion 61, and the first bending portion 61 is disposed between the two extending arms.As shown in FIG. 3, in the present embodiment, a first through hole 323 is formed on the yoke iron 3 and at a position near the end portion 321 of the second part 32. The second bent portion 62 of the movable spring 6 is passed through the first through hole 323 and is fixed to the armature 5. The two movable spring extension arms 63 extend along the parts of the yoke iron at two sides of the first through hole 323, respectively.As shown in FIG. 3, in the present embodiment, the first through hole 323 of the yoke iron 3 is shaped as a rectangular shape. A side wall of the first through hole 323 remote from the end portion 321 of the second part 32 of the yoke iron 3 is the blade of the yoke iron, that is, the wall of the first through hole 323 contacting the armature 5 is the blade.In the present disclosure, the guide pin 322 of the yoke iron 3 is disposed in the position parallel to the axis of the coil, and the installation is provided reversely to realize the mounting. Therefore, the presence of the first through hole 323 is required to allow the second bending portion 62 of the movable spring 6 to pass through the first through hole 323 and then to be fixed to the armature 5. And, the cutting edge of the yoke iron 3 is a wall of the first through hole 323 remote from the guide pin 322 of the yoke iron 3.As shown in FIG. 3, the guide pin 322 of the yoke iron 3 is provided at the center of the end piece 321 of the second part 32 of the yoke iron 3.As shown in FIG. 4, in the present embodiment, the movable spring 6 is provided with a second through hole 64 having a strip shape. The second through hole 64 first extends in the direction approximately parallel to the first bent portion 61 and then is bent to extend in the direction approximately parallel to the second bent portion 62 of the movable spring 6.Further, as shown in FIG. 5, between the second part 32 of the yoke iron 3 and a winding window of the coil 2, an insulating plate 8 is disposed to increase a creepage distance between the enameled wire 1 of the coil 2 at the position corresponding to the winding window and the yoke iron 3.In the present embodiment, the insulating plate 8 is further coated on both sides of the second part 32 of the yoke iron 3 in the width direction.Further, as shown in FIG. 1, a bottom plate component 9 is further included. The guide pin 322 of the yoke iron at the end portion of the second part 32 of the yoke iron 3 is inserted into the bottom plate component 9. The bottom plate component 9 is joined to the coil 2 by clamping.In the electromagnetic relay of the present disclosure, it is provided that an end portion 321 of the second part 32 of the yoke iron 3 is provided with a guide pin 322 of the yoke iron that is parallel to an axis of the coil 2. the first bending portion 61 of the movable spring 6 is provided with a movable spring extending arm 63 that extends toward the end portion 321 of the second part 32 of the yoke iron 3. And, the movable spring extension arm 63 is connected to the end piece 321 of the second part 32 of the yoke iron 3 to achieve the electrical connection between the movable spring 6 and the guide pin 322 of the yoke iron. This structure of the present disclosure simplifies the shape of the structure of the movable spring by arranging the lead-out portions of the movable spring 6 on the yoke iron 3, which is advantageous for the miniaturization and compactness of the product. The present disclosure establishes the electrical connection between the movable spring 6 and the guide pin 322 of the yoke iron by providing the movable spring extension arms 63 on the movable spring 6. That is, the current flowing through the movable contact can directly reach the guide pin 322 of the yoke iron by the movable spring extension arm 63 when flowing through the movable spring, and a conductive path of the yoke iron can be shortened. When there is no extension arm of the movable spring, the current in the yoke iron needs to travel a long distance, thus the structure of the movable spring 6 in the present disclosure can reduce an impedance of a conductor loop and a temperature rise of the conductor loop, so that the electromagnetic relay in the present disclosure has characteristics of: a small temperature rise of the conductor loop, a simple structure and a small volume, a good mounting property, and a good workability. Moreover, in the present disclosure, the structure in which the movable spring extension arm 63 is joined to the guide pin 322 of the yoke iron is provided, as compared with a conventional method using guide pin coatings of the movable spring, the difficulty of the manufacturing process of the movable spring is greatly reduced, thereby simplifying the structure of the movable spring and making the process easily feasible.In the electromagnetic relay of the present disclosure, it is provided that the movable spring lead-out portion is provided on the yoke iron 3, and the insulating plate 8 is further disposed between the surface of the second part 32 of the yoke iron 3 and a winding window of the coil 2. The creepage distance between the enamelled wire 1 of the coil 2 at the position corresponding to the winding window and the yoke iron 3 is increased using the insulating plate 8. That is, the creepage distance between a load circuit and a coil circuit is increased, so that a required withstand voltage of the product can be improved.The above are only preferred embodiments of the present disclosure and are not intended to limit the present disclosure in any way. Although the present disclosure has been described above in the preferred embodiments, the present disclosure is not intended to be limited. Using the technical content disclosed above, a person skilled in the art can make many possible changes and modifications to the technical solutions of the present disclosure, or can change to equivalent embodiments without departing from the scope of the technical solutions of the present disclosure. Therefore, any simple modifications, equivalent changes, and modifications to the above embodiments according to the technical core of the present disclosure are included in the scope of the present disclosure.

Claims

An electromagnetic relay comprising: a magnetic circuit system and a contact system, wherein the magnetic circuit system comprises a enamelled wire (1), a coil (2), a yoke iron (3), an iron core (4) and an armature (5); the enamelled wire (1) is wound around the coil (2) to form a coil structure; the iron core (4) is inserted through a through hole of the coil (2); wherein the yoke iron (3) comprises a first part (31) and a second part (32) formed in an approximately L-shaped structure; the first part (31) of the yoke iron (3) is connected to an end of the iron core (4); the second part (32) of the yoke iron (3) is disposed at a winding window side of the coil (2); wherein the contact system comprises a movable spring (6), a fixed spring (7), a movable contact (60) cooperating with the movable spring (6) and a fixed contact (70) cooperating with the fixed spring (7); the fixed spring (7) is mounted on the coil (2); the fixed spring (7) is provided with a fixed spring guide pin (71); the movable spring (6) is bent in a substantially L-shaped shape and comprises a first bending portion (61) and a second bending portion (62); the first bending portion (61) of the movable spring (6) is fixed to the second part (32) of the yoke iron (3); the second bent portion (62) of the movable spring (6) is fixed to the armature (5) and the armature (5) abuts a blade of the yoke iron (3) corresponding to the other end of the iron core (4); and the first bent portion (61) of the movable spring (6) is provided with a movable spring extending arm (63) extending toward the end portion (321) of the second part (32) of the yoke iron (3); characterized in that an end portion (321) of the second part (32) of the yoke iron (3) is provided with a guide pin of the yoke iron (3) parallel to an axis of the coil (2); the movable spring extension arm (63) is connected to the end piece (321) of the second part (32) of the yoke iron (3) to achieve the electrical connection between the movable spring (6) and the guide pin (322) of the yoke iron (3); a first through hole (323) is formed on the yoke iron (3) and at a position near the end piece (321) of the second part (32) of the yoke iron (3); and the second bent portion (62) of the movable spring (6) is guided by the first through hole (323) and is fixed to the armature (5).The electromagnetic relay according to claim 1, wherein an end part of the end part (321) of the first bent portion (61) of the movable spring (6) is fixed to the second part (32) of the yoke iron (3); the number of the extension arms (63) of the movable spring is two; wherein the two extension arms (63) of the movable spring, each formed by the end part of the end part (321) of the first bent portion (61) of the movable spring (6), extend toward the end part (321) of the second part (32) of the yoke iron (3).The electromagnetic relay according to claim 2, wherein the two movable spring extension arms (63) extend along the parts of the yoke iron (3), respectively, at two sides of the first through hole (323).The electromagnetic relay according to claim 3, wherein the first through hole (323) of the yoke iron (3) is shaped as a rectangular shape; wherein a side wall of the first through hole (323) remote from the end piece (321) of the second part (32) of the yoke iron (3) is the cutting edge of the yoke iron (3).The electromagnetic relay according to claim 2, wherein the guide pin (322) of the yoke iron (3) is provided at the center of the end piece (321) of the second part (32) of the yoke iron (3).The electromagnetic relay according to claim 1, wherein the movable spring (6) is provided with a second through hole (64) having a strip shape; the second through hole (64) first extends in the direction approximately parallel to the first bent portion (61), and then bent to extend in the direction approximately parallel to the second bent portion (62) of the movable spring (6).The electromagnetic relay according to claim 1, wherein an insulating plate (8) is further disposed between the second part (32) of the yoke iron (3) and a winding window of the coil (2) to increase a creepage distance between the enameled wire (1) of the coil (2) at the position corresponding to the winding window and the yoke iron (3).The electromagnetic relay according to claim 7, wherein the insulating plate is further coated on both sides of the second part (32) of the yoke iron (3) in the width direction thereof.The electromagnetic relay according to claim 1, wherein the electromagnetic relay further comprises a bottom plate (9); the guide pin (322) of the yoke iron (3) is inserted into the bottom plate component at the end piece (321) of the second part (32) of the yoke iron (3); the bottom plate component is joined to the coil (2) by clamping.

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