Relay

Abstract

To provide a relay excellent in both inrush resistance and current-carrying / contact reliability.SOLUTION: The relay 10 includes an electromagnet 14, a base 34 on which the electromagnet 14 is arranged, a fixed contact member 42 fixed to the base 34, and a movable contact spring member 44 supported by the base 34 and elastically deformed by the operation of the electromagnet 14. The fixed contact member 42 has a first fixed contact 48 and a second fixed contact 52, and the movable contact spring member 44 has a first movable contact 64 facing the first fixed contact 48 and a second movable contact 70 facing the second fixed contact 52. The distance of the first movable contact 64 along the shape of the movable contact spring member 44 from the portion serving as the fulcrum of the elastic deformation of the movable contact spring member 44 is longer than the distance of the second movable contact 70 along the shape of the movable contact spring member 44 from the portion.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a relay. [Background technology]

[0002] In electromagnetic relays, there are known ones in which a movable contact spring member constituting a contact section is configured to connect a terminal fixed to a circuit board with a contact spring element having a movable contact by combining them together. The contact section is composed of a movable contact spring member having a movable contact and a fixed contact member having a fixed contact facing the movable contact, and the pair of contacts has the functions of both breaking and conducting a load.

[0003] The materials that make up the contacts are chosen depending on the purpose and application. For example, when priority is placed on inrush resistance, contacts made of materials with a relatively high melting point and high hardness are used, while when priority is placed on reliability of current flow and contact, contacts made of materials with a relatively low melting point and low hardness are often used. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-059702 [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-176957 Summary of the Invention [Problem to be solved by the invention]

[0005] There is a trade-off between the materials that make up the contacts based on their properties: for example, a silver-tin material with excellent inrush resistance has lower contact reliability than a silver-nickel material. On the other hand, a silver-nickel material with excellent contact reliability has a lower melting point than a silver-tin material, so when an inrush current flows, the contact points become hot and are prone to welding.

[0006] Therefore, a relay with excellent inrush resistance and current / contact reliability is desired. [Means for solving the problem]

[0007] One aspect of the present disclosure is a relay comprising: an electromagnet; a base on which the electromagnet is disposed; a fixed contact member fixed to the base; and a movable contact spring member supported by the base and elastically deformed by operation of the electromagnet, wherein the fixed contact member has a first fixed contact and a second fixed contact; the movable contact spring member has a first movable contact facing the first fixed contact and a second movable contact facing the second fixed contact; and the distance of the first movable contact from a position that serves as a fulcrum for elastic deformation of the movable contact spring member along the shape of the movable contact spring member is longer than the distance of the second movable contact from the position along the shape of the movable contact spring member. [Effects of the Invention]

[0008] According to the present disclosure, two sets of contacts can be opened and closed at different times, allowing separate sets of contacts to perform the functions of breaking the load and conducting current, thereby providing a relay with excellent inrush resistance and current-carrying / contact reliability. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of an electromagnetic relay according to an embodiment. [Figure 2] FIG. 2 is an exploded perspective view of the electromagnetic relay of FIG. 1. [Figure 3] FIG. 4 is a plan view showing a movable contact spring member. [Figure 4] FIG. 2 is a partially enlarged view showing a state in which both the first contact set and the second contact set are open. [Figure 5] FIG. 5 is a view of the state of FIG. 4 from a different angle. [Figure 6] FIG. 2 is a partially enlarged view showing a state in which the first contact set is closed and the second contact set is open. [Figure 7] FIG. 2 is a partially enlarged view showing a state in which both the first and second contact sets are closed. DETAILED DESCRIPTION OF THE INVENTION

[0010] FIG. 1 is a perspective view of an electromagnetic relay (relay) 10 according to an embodiment, and FIG. 2 is an exploded perspective view of the relay 10. The relay 10 includes a base unit 12, an electromagnet 14 fixed to the base unit 12, and an armature 16 disposed on one end of the electromagnet 14 and attracted by magnetic force generated when the electromagnet 14 is activated. The electromagnet 14 includes an insulating bobbin 18, a coil 20 wound around the bobbin 18, an iron core 22 disposed within the bobbin 18, a substantially L-shaped yoke 24 coupled to one end of the iron core 22 and forming a magnetic circuit in cooperation with the iron core 22, and two coil terminals 26, one end of which is connected to the coil 20 and the other end of which is connected to an external power source (not shown). The armature 16 is a flat plate-shaped member formed, for example, from magnetic steel, and is elastically and displaceably connected to the yoke 24 via a hinge spring 28, and is disposed opposite a head 30 of the iron core 22. The hinge spring 28 functions as an elastic hinge between the yoke 24 and the armature 16 and urges the armature 16 in a direction away from the head 30 of the core 22 by its own spring action.

[0011] The base unit 12 is a member that houses the electromagnet 14 and a contact portion 32, which will be described later, and has a base portion 34 and a case portion 36 that houses the electromagnet 14, and can be molded integrally by resin molding or the like. An operating member (card) 38 having a recess 40 that engages with the armature 16 is disposed above the case portion 36, and the card 38 can be displaced in the front-to-rear direction parallel to the axial direction of the iron core 22 when the electromagnet 14 is magnetized or demagnetized. Note that in this embodiment, for convenience, the front-to-rear direction parallel to the axial direction of the iron core 22 is referred to as the z-direction, the width direction perpendicular to the z-direction is referred to as the x-direction, and the height direction perpendicular to both the x- and z-directions is referred to as the y-direction.

[0012] The contact section 32 is composed of a fixed contact member 42 and a movable contact spring member 44 (see FIG. 3 described later). The fixed contact member 42 has a substantially L-shaped fixed contact support section 46, a first fixed contact 48 provided at one end of the fixed contact support section 46, a terminal section 50 extending from the other end of the fixed contact support section 46, and a second fixed contact 52 provided at the middle portion of the substantially L-shape. The terminal section 50 is inserted into and fixed in an insertion hole 54 formed in the base section 34 of the base unit 12. The relay 10 is configured to fit into the base unit 12 and may have a cover (not shown) that cooperates with the base unit 12 to house the above-mentioned components.

[0013] The movable contact spring member 44 is composed of a contact spring element 56 and a terminal 58. The contact spring element 56 has a generally C-shape or U-shape and includes an intermediate portion 60, a first end portion 62 extending from one end of the intermediate portion 60, a first movable contact 64 provided at the first end portion 62, a second end portion 68 extending from the other end of the intermediate portion 60 and having a through hole 66 formed therein, and a second movable contact 70 provided at the intermediate portion 60. The second end portion 68 may be bent slightly along an angled bend line 71 with respect to the x or y direction to generate a twisting action during elastic deformation of the contact spring element 56 and improve contact between the contacts.

[0014] The contact spring element 56 has a through hole 72 formed by burring or the like, and by engaging the rod-shaped protrusion 74 of the card 38 within the through hole 72, the displacement direction of the movable contact accompanying the displacement of the card 38 is restricted to be roughly along the z direction, thereby stabilizing operation as a relay.

[0015] The terminal 58 has a tab-shaped portion 78 having a through hole 76 formed by burring or the like, and a terminal portion 80 extending downward from the tab-shaped portion 78, and the tab-shaped portion 78 is inserted into and fixed in an insertion hole 81 formed in the base portion 34 of the base unit 12. By aligning the through hole 66 with the through hole 76 and crimping them, the movable contact spring member 44 is formed in which the contact spring element 56 and the terminal 58 are substantially integrally joined. Note that although the movable contact spring member 44 in the illustrated example is formed by assembling the contact spring element 56 and the terminal 58 together, it may also be formed by processing a material that is substantially a single member.

[0016] The first fixed contact 48 of the fixed contact member 42 and the first movable contact 64 of the movable contact spring member 44 face each other to form a first contact set, and the second fixed contact 52 of the fixed contact member 42 and the second movable contact 70 of the movable contact spring member 44 face each other to form a second contact set. The behavior of each contact set will be explained below.

[0017] Fig. 4 is a partially enlarged view showing a state in which both the first and second contact sets are open, and Fig. 5 is a view of the state shown in Fig. 4 from a different angle. The movable contact spring member 44 is configured to elastically deform when the electromagnet 14 is activated. Specifically, when the card 38 is displaced in the direction of arrow 84 as the electromagnet 14 is energized or deenergized, a protrusion 82 formed on the z-direction end of the card 38 presses the first end 62 of the movable contact spring member 44 in approximately the z-direction toward the fixed contact member 42. Accordingly, the contact spring element 56 elastically deforms, and the first movable contact 64 and the second movable contact 70 elastically displace toward the first fixed contact 48 and the second fixed contact 52, respectively.

[0018] 6 is a partially enlarged view showing a state in which the first contact set is closed and the second contact set is open. As shown in FIG. 3, the contact spring element 56 is connected at its second end 68 to a terminal 58 fixed to the base 34. Therefore, when pressed by the card 38, the movable contact spring member 44 elastically deforms with the second end 68 as a fulcrum. Here, the second movable contact 70 is formed on the intermediate portion 60, one end of which is connected to the second end 68, and the first movable contact 64 is formed on the first end 62, the other end of which is connected to the intermediate portion 60. Therefore, the distance (without a space) of the first movable contact 64 along the C-shape or U-shape from the portion (here, the second end 68) that serves as the fulcrum for the elastic deformation of the contact spring element 56 is longer than the distance of the second movable contact 70 along the C-shape or U-shape from the same portion. Therefore, when a specific portion (here, the first end portion 62) of the movable spring element 56 is pressed, the amount of elastic displacement of the first movable contact 64 is greater than that of the second movable contact 70. As a result, as shown in Fig. 6, the first movable contact 64 first comes into contact with the first fixed contact 48 to close the first contact set, while the second contact set is still open.

[0019] Figure 7 is a partially enlarged view showing a state in which both the first and second contact sets are closed. When the card 38 is further displaced in the direction of arrow 84 from the state in Figure 6, the second movable contact 70 comes into contact with the second fixed contact 52 while the first contact set remains closed, and the second contact set is closed. When the card 38 is displaced in the direction opposite to the arrow 84 from the state in Figure 7, the second contact set first opens, resulting in the state shown in Figure 6. When the card 38 is further displaced in the direction opposite to the arrow 84, the first contact set also opens, resulting in the state shown in Figure 5.

[0020] In this manner, in this embodiment, the timing at which the two contact sets make and break can be shifted by pressing one point on the movable contact spring member 44. Therefore, it is preferable to use a material that emphasizes inrush resistance for the first contact set that makes first, and a material that emphasizes electrical conductivity for the second contact set that makes last.

[0021] Specifically, the material forming the first movable contact 64 and first fixed contact 48 that make up the first contact set preferably contains a silver-tin-based material (such as AgSnO2) that has excellent inrush resistance. Because an inrush current flows through the first contact set when it is closed, by using a silver-tin-based material with a relatively high melting point to prevent welding even when the contact points become hot, welding is less likely to occur and the load can be suitably interrupted when contact is made.

[0022] On the other hand, the material forming the second movable contact 70 and second fixed contact 52 constituting the second contact set preferably includes a silver-nickel-based material (such as AgNi), which has excellent reliability in electrical conduction and contact. Silver-nickel-based materials have a lower melting point than silver-tin-based materials, but also have lower hardness, resulting in high reliability in electrical conduction and contact between the contacts. Furthermore, silver-tin-based materials have high electrical conductivity, which is advantageous in terms of heat generation. As described above, according to this embodiment, the load interruption and electrical conduction functions are assigned to separate contact sets, and the optimal material can be selected for each contact set, making it possible to provide a relay with excellent inrush resistance and electrical conduction / contact reliability.

[0023] Furthermore, by arranging the second contact set closer to the second end 68, which serves as the fulcrum for elastic displacement, than the first contact set, the conductor resistance is reduced, which is advantageous in terms of heat dissipation from the terminal 58 to the circuit board (not shown), and it is possible to suppress heat generation in the movable contact spring member 44. Furthermore, it becomes possible to arrange the first contact set and the second contact set relatively far apart within essentially the same circuit, which makes the first contact set less susceptible to the effects of heat generated by current flow, which is expected to improve inrush resistance and suppress wear, further improving the life of the relay. [Explanation of symbols]

[0024] 10 relay, 12 base unit, 14 electromagnet, 16 armature, 18 bobbin, 20 coil, 22 iron core, 24 yoke, 28 hinge spring, 34 base, 36 case portion, 38 card, 42 fixed contact member, 44 movable contact spring member, 46 fixed contact support part, 48 first fixed contact, 52 second fixed contact, 56 contact spring element, 60 intermediate portion, 62 first end portion, 64 first movable contact, 68 second end, 70 second movable contact, 74 convex portion, 78 tab-shaped portion, 82 protrusion

Claims

1. An electromagnet and a base on which the electromagnet is disposed; a fixed contact member fixed to the base; a movable contact spring member supported on the base and elastically deformed by operation of the electromagnet, the fixed contact member has a first fixed contact and a second fixed contact, the movable contact spring member has a first movable contact facing the first fixed contact and a second movable contact facing the second fixed contact, A relay in which a distance of the first movable contact from a portion that serves as a fulcrum for elastic deformation of the movable contact spring member along the shape of the movable contact spring member is longer than a distance of the second movable contact from the same portion along the shape of the movable contact spring member.

2. the movable contact spring member includes a contact spring element having a substantially C-shape or a substantially U-shape, and a terminal fixed to the base; 2. The relay of claim 1, wherein the contact spring element has an intermediate portion having the second movable contact, a first end extending from one end of the intermediate portion and having the first movable contact, and a second end extending from the other end of the intermediate portion and connected to the terminal.

3. 3. The relay of claim 2, further comprising a card configured to be displaced by actuation of the electromagnet and to press against the first end of the movable contact spring member.

4. The relay according to any one of claims 1 to 3, wherein a material forming the first movable contact and the first fixed contact has a higher melting point and a higher hardness than a material forming the second movable contact and the second fixed contact.

5. 5. The relay according to claim 4, wherein a material forming the first movable contact and the first fixed contact includes a silver-tin based material, and a material forming the second movable contact and the second fixed contact includes a silver-nickel based material.

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