Electromagnetic relay

Abstract

To provide an electromagnetic relay capable of suppressing a large size of an increase of the number of components in minimum, and having a high insulation quality.SOLUTION: An electromagnetic relay 10 comprises: a coil 16; a bobbin 14 to which the coil 16 is wound; an iron core 18 that is inserted into the bobbin 14; an electric magnet 20 that is cooperated with the iron core 18, and includes a yoke 22 for forming a magnetic circuit; a movable terminal 26 that includes a movable contact 24 that is operated in accordance with an operation of the electric magnet 20; fixed terminals 32 and 36 that include fixed contacts 30 and 34 that are arranged oppositely to the movable contact 24; a coil terminal 28 that is connected to the coil 16 while being attached to the bobbin 14; an insulation member 40 that is arranged between the coil 16 and the yoke 22; and a base 12 that includes a wall part 98 for insulating a gap between the coil terminal 28 and the fixed terminals 32 and 36.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an electromagnetic relay.

Background Art

[0002] An electromagnetic relay (relay) is configured to open and close contacts by passing an electric current through a coil, and there is a hinge-shaped electromagnetic relay having an armature (yoke) connected to an iron core and a contact pole (armature) configured to be movable with respect to the armature.

[0003] In an electromagnetic relay having a coil and an armature, a technique is known in which an insulating material is disposed between the coil and the armature to insulate between the two members. Further, a technique is known in which a flange portion is provided on a bobbin around which a coil is wound to increase the insulation distance between the coil and an electronic component.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Summary of the Invention

Problems to be Solved by the Invention

[0005] In electromagnetic relays for low-voltage applications, the requirements for the electrical insulation performance between components are not relatively high. However, for electromagnetic relays that can handle high voltages and high currents, such as those used in on-vehicle chargers for electric vehicles and the like, high insulation performance is required. As means for improving the insulation performance, there are methods of increasing the physical distance between components or arranging an insulating material between components. However, the former method has the problem that the electromagnetic relay becomes larger in size, and the latter method has the problem that the number of components increases.

[0006] Therefore, an electromagnetic relay that minimizes the increase in size and the increase in the number of components and realizes high insulation is desired.

Means for Solving the Problem

[0007] One aspect of the present disclosure is an electromagnetic relay including a coil, a bobbin around which the coil is wound, an iron core inserted into the bobbin, an armature that cooperates with the iron core to form a magnetic circuit, a movable terminal having a movable contact that operates in accordance with the operation of the electromagnetic magnet, a fixed terminal having a fixed contact disposed opposite to the movable contact, a coil terminal attached to the bobbin and connected to the coil, an insulating member disposed between the coil and the armature, and a base having a wall portion that insulates between the coil terminal and the fixed terminal.

Effect of the Invention

[0008] According to the present disclosure, there is provided an electromagnetic relay that suppresses an increase in the number of components, reduces the size of the electromagnetic relay, and can insulate each part.

Brief Description of the Drawings

[0009]

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Embodiments for Carrying Out 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 FIG. 1. The relay 10 is, for example, a relay used in an in-vehicle charger, and includes a base 12 and an electromagnet 20 assembled to the base 12. The electromagnet 20 includes a bobbin (winding frame) 14, a coil 16 wound around the bobbin 14, an iron core 18 disposed within the bobbin 14, and a substantially L-shaped armature (yoke) 22 coupled to one end of the iron core 18 and cooperating with the iron core 18 to form a magnetic circuit. The relay 10 also includes an armature 25 that is attracted to the head, which is the other end of the iron core 18, as the electromagnet 20 operates, and a movable terminal 26 having two movable contacts 24 that operate in a direction of approaching and separating from the head of the iron core 18 corresponding to the operation of the armature 25, and two coil terminals 28 connected to both ends of the coil winding 16. In the illustrated example, the coil terminals 28 are attached to the bobbin 14. Also, the movable contacts 24 are attached near the tip of a movable spring.

[0011] The relay 10 has a fixed terminal including fixed contacts disposed to face the movable contacts 24. The relay 10 is a so-called 1c contact configuration relay, and as the fixed terminals, it has a first fixed terminal (break terminal) 32 having two fixed normally closed contacts (break contacts) 30 and a second fixed terminal (make terminal) 36 having two fixed normally open contacts (make contacts) 34. In the illustrated example, the first fixed terminal 32 and the second fixed terminal 34 are each attached to the bobbin 14. The movable contacts 24 contact the fixed normally closed contacts 30 when the electromagnet 20 is OFF, and contact the fixed normally open contacts 34 when the electromagnet 20 is ON. Since each of the movable terminal 26, the break terminal 32, and the make terminal 36 has two contacts, a relay 10 with high current-carrying performance can be obtained. The assembly of the relay 10 can be automatically performed using an assembly machine or the like, but it can also be performed manually.

[0012] Relay 10 is configured to fit into base 12 and has a cover 38 that cooperates with base 12 to accommodate the above-described components, and an insulating member 40 configured and arranged to electrically insulate between coil 16 and armature 22. For clarity of the components of relay 10, cover 38 is omitted in FIG. 1. Among the above components, base 12, bobbin 14, cover 38, and insulating member 40 are made of an electrically insulating resin material and can be formed, for example, by injection molding.

[0013] In this embodiment, for convenience, the direction parallel to the axial direction of core 18 is referred to as the z-direction (height direction), the direction perpendicular to the z-direction and in the arrangement direction of the two movable contacts 24 or the two fixed contacts 30 or 34 is referred to as the y-direction (width direction), and the direction perpendicular to both the y-direction and the z-direction is referred to as the x-direction (front-rear direction).

[0014] FIG. 3 is a perspective view showing a structural example of insulating member 40, FIG. 4 is a perspective view of insulating member 40 viewed from a direction different from that of FIG. 3, and FIG. 5 is a cross-sectional view taken along line A-A in FIG. 3. Further, FIG. 6 is a cross-sectional view taken along line A'-A' parallel to the z-direction in FIG. 1, and FIG. 7 is a cross-sectional view taken along line A''-A'' perpendicular to the z-direction in FIG. 6.

[0015] Insulating member 40 is disposed between coil 16 and armature 22 and has a wall portion 42 extending substantially in the z-direction, a fitting portion 44 provided at the lower portion of wall portion 42 (opposite side to the contacts) into which the lower flange portion 48 of bobbin 14 (see FIGS. 9 etc. described later) fits, and a shielding portion 46 provided at the upper portion of wall portion 42 to cover the upper flange portion 50 of bobbin 14 (see FIGS. 9 etc. described later). Insulating member 40 further has an overhanging portion 52 extending from wall portion 42 in a substantially tangential direction of coil 16.

[0016] By inserting the lower flange portion 48 into the fitting portion 44 by press-fitting or the like, the insulating member 40 is fixed to the bobbin 14. The fitting portion 44 is defined by the lower surface of the overhanging portion 52 and the bottom portion 54 spaced apart below the overhanging portion 52. At this time, in order to smoothly fit the lower flange portion 48 into the fitting portion 44, as shown in FIG. 5, the lower end 53 of the overhanging portion 52 preferably has a tapered shape that narrows in width from the right side to the left side in the direction perpendicular to the z direction. Further, the bottom portion 54 and the lower end 53 of the overhanging portion 52 preferably each have a rib 56 for guiding the lower flange portion 48 when it is inserted. As shown in FIG. 8, since the lower flange portion 48 inserted into the fitting portion 44 is sandwiched by the ribs 56 arranged above and below it, it is possible to more reliably fix the fitting portion 44 and the lower flange portion 48 with the ribs 56.

[0017] By arranging the insulating member 40 according to the present embodiment between the coil 16 and the yoke 22, as shown in FIGS. 6 and 7, the insulation distances d1 and d2 between the coil 16 and the yoke 22 or the contact pole 25 can be made significantly longer than the insulation distance d3 when it is assumed that there is no insulating member 40. Further, since the insulating member 40 has the overhanging portion 52, as shown in FIG. 7, the insulation distance d7 between the coil 16 and the movable terminal 26 can be made significantly longer than the insulation distance d8 when it is assumed that there is no overhanging portion 52.

[0018] As shown in FIG. 8, in order to make the fitting between the insulating member 40 and the bobbin 14 stronger, a concave fitting portion 71 may be formed on the bobbin 14 side, and a tapered portion 58 shown in FIGS. 3 and 4 may be formed on the bottom portion 54 of the insulating member 40.

[0019] The insulating member 40 contacts the bobbin 14 only at the fitting portion 44 and does not contact the upper flange portion 50 of the bobbin 14. Therefore, the flange portion 46 of the insulating member 40 has the effect of covering the upper flange portion 50 and increasing the insulation distance between the coil 16 and the yoke 22, but does not contact the upper flange portion 50. For example, as shown in FIG. 5, the flange portion 46 may have a tapered shape that tapers as it moves away from the wall portion 42 in order to more surely prevent contact with the upper flange portion 50.

[0020] Since the insulating member 40 does not contact the bobbin 14 except at the fitting portion 44, during the assembly of the relay 10, it does not slide with other members except the fitting portion 44 and the lower flange portion 48. Generally, in a relay, chips and the like are generated due to press-fitting and sliding between members during assembly, and the opening and closing operation of the contacts may be hindered by the chips. However, in this embodiment, by limiting the portions where chips and the like can be generated due to sliding to positions away from the contacts, the amount of chips generated is suppressed, and the generated chips do not adversely affect the operation of the relay. In this way, since the insulating member 40 contacts the bobbin 14 only at the lower part of the relay 10, and on the other hand, the movable contact and the fixed contact are provided at the upper part of the relay 10, even if chips are generated at the lower part of the relay, factors that can cause malfunction of the relay, such as chips getting into the space between the movable contact and the fixed contact provided at the upper part of the relay, can be reduced.

[0021] When winding the winding for forming the coil 16 around the bobbin 14, the lower flange portion 48 or the upper flange portion 50 may warp. Therefore, if both the lower flange portion 48 and the upper flange portion 50 are fixed to other members, the bobbin may interfere with other members during assembly, making assembly difficult. However, in this embodiment, since the upper flange portion 50 has a structure with a gap without contacting other members, interference between the upper flange portion 50 and other members can be prevented even if there is warping.

[0022] As described above, since the insulating member 40 fits with the bobbin 14 at the fitting portion 44, it is desirable that the lower part of the insulating member 40 does not get distorted during molding. Therefore, the portion constituting the fitting portion 44 of the insulating member 40 preferably has a constant wall thickness. By making the wall thickness constant, for example, distortion during injection molding can be suppressed.

[0023] When the armature 22 is formed by bending a metal plate, there is a possibility that the bent armature 22 may contact the insulating member 40. Therefore, as shown in FIG. 5, the insulating member 40 preferably has a relief portion 60 in order to avoid contact with the portion corresponding to the inner R of the bend of the armature 22.

[0024] As illustrated in FIG. 9, when caulking the movable spring 62 that constitutes the movable terminal 26 to the armature 22 at position 27 during the assembly of the relay 10, it may be necessary to insert a jig on the back side of the armature 22 corresponding to position 27. However, depending on the shape of the insulating member, it may be difficult or impossible to insert the jig. Therefore, in order to secure a space for inserting the jig, as shown in FIGS. 3 and 4, it is preferable that the insulating member 40 has a concave portion 64 on the side facing the armature 22 of the overhanging portion 52. In this way, as shown in FIG. 7, the insulating member 40 forms a substantially U-shaped in top view, and a space for inserting a jig can be secured between the insulating member 40 and the armature 22.

[0025] As shown in FIG. 6, the eaves portion 46 of the insulating member 40 has a shape that projects in the x direction and toward the contact side (right side in FIG. 6) so as to increase the insulation distance between the coil 16 and the armature 22. Here, further, as shown in part B of FIG. 10, the eaves portion 46 may have an extension portion 66 that projects in the y direction from the upper flange portion 50 of the bobbin 14 and does not contact the cover 38. With the extension portion 66, the insulation distance between the coil 16 and the armature 22 can be further increased.

[0026] The insulating member 40 preferably has a structure that prevents malfunction of the relay 10 and facilitates assembly. For example, as shown in FIG. 8, it is preferable that the upper end surface 68 of the eaves portion 46 of the insulating member 40 is at a position slightly lower than the upper end 70 of the bobbin 14 (located on the non-contact side in the z direction). If the upper end surface 68 extends above the upper end 70, the contact terminal 25 may contact the upper end surface 68 during operation, resulting in malfunction of the relay 10. However, by configuring as shown in FIG. 8, this can be prevented. Also, it is preferable that the lower end surface 72 of the bottom portion 54 of the insulating member 40 is at a position slightly higher than the lower end 74 of the bobbin 14 (located on the contact side in the z direction). In this way, it is possible to prevent the armature 22 from contacting the lower end surface 72 during the assembly of the relay 10, facilitating the assembly.

[0027] FIG. 11 is a perspective view showing a structural example of the bobbin 14, and FIG. 12 is a perspective view of the bobbin 14 viewed from a direction different from that of FIG. 11. FIGS. 13 to 15 are a front view seen along a direction C parallel to the x direction, a side view seen along a direction D parallel to the y direction, and a bottom view of the bobbin 14 seen along a direction E parallel to the z direction in FIG. 11, respectively.

[0028] The bobbin 14 has a hollow cylindrical body portion 47 around which the coil 16 is wound, and a lower flange portion 48 and an upper flange portion 50 provided at both longitudinal ends of the body portion 47. In a state where the relay 10 is assembled, the lower flange portion 48 is received in the base 12, the body portion 47 extends in the vertical direction (z direction) with respect to the base 12, and the upper flange portion 50 is disposed above the base 12 and substantially parallel to the lower flange portion 48. Each of the lower flange portion 48 and the upper flange portion 50 is a substantially rectangular plate-like element that projects from the body portion 47 in a direction substantially perpendicular to its longitudinal direction (a direction parallel to the xy plane).

[0029] As described above, the lower flange portion 48 of the bobbin 14 is fitted into the fitting portion 44 of the insulating member 40 by press-fitting or the like. Therefore, the lower flange portion 48 preferably has a tapered portion 76 that facilitates insertion into the fitting portion 44. Further, as shown in FIGS. 12 and 15, the lower flange portion 48 of the bobbin 14 preferably has a tapered portion 78 that abuts against and guides the tapered portion 58 of the insulating member 40 to facilitate insertion of the tapered portion 58 into the fitting portion 71.

[0030] The lower flange portion 48 of the bobbin 14 has functions such as preventing the winding of the winding forming the coil 16, fixing the insulating member 40, and securing an insulating distance between the coil 16 and the armature 22. Here, in order to further extend the insulating distance between the coil 16 and the armature 22 and between the coil 16 and the contact terminal 25, the lower flange portion 48 may have a stepped portion 80 that extends forward in the x direction toward the armature 22. Similarly, the upper flange portion 50 may have a stepped portion 82 that extends forward in the x direction toward the armature 22. The stepped portions 80 and 82 extending in the x direction can further extend the insulating distances d1 and d2 shown in FIG. 6.

[0031] Also, as shown in FIGS. 13-14, the lower flange portion 48 may have a wall portion 84 for ensuring an insulation distance between the coil 16 and the armature 22. The wall portion 84 can ensure a relatively long insulation distance d4 between the coil 16 and the armature 22 as compared with the case where there is no wall portion 84 as shown in FIG. 6.

[0032] FIG. 16 is a perspective view showing a structural example of the base 12, FIG. 17 is a perspective view of the base 12 viewed from above in the z direction, and FIG. 18 is a cross-sectional view taken along the line F-F in FIG. 17. The base 12 has a frame portion 86 extending in a substantially rectangular outline when viewed from above, and a bottom portion 90 that partially closes an opening 88 defined by the lower end of the frame portion 86, and is configured to receive the components of the relay 10 described above and fix them in predetermined positions.

[0033] In the bottom portion 90 of the base 12, a first hole 92 through which the movable terminal 26 described in FIG. 2 and the like is inserted, a second hole 94 through which the coil terminal 28 is inserted, and a third hole 96 through which the fixed terminals 32 and 36 are inserted are formed. The base 12 also has a wall portion 98 for ensuring an insulation distance between the coil terminal 28 and the fixed terminals 32 and 36. The wall portion 98 extends upward in the z direction from the bottom surface 90 of the base 12 and has a substantially U-shaped shape when viewed from above, and is arranged adjacent to the third hole 96 so as not to interfere with the assembly of other members.

[0034] As shown in FIG. 6, the wall portion 98 can ensure an insulation distance d5 longer than the insulation distance d6 in the case where it is assumed that there is no wall portion 98 between the coil terminal 28 and the fixed terminal 36. Also, since the wall portion 98 has a substantially U-shaped shape when viewed from above, as shown in FIG. 7, a relatively long insulation distance d9 can be ensured between the coil terminal 28 and the fixed terminal 36.

[0035] Since the wall portion 98 can be integrally formed by injection molding or the like of resin as a part of the base 12, providing the wall portion 98 does not increase the number of parts of the electromagnetic relay 10. Also, there is no need to increase the size of the base 12 to form the wall portion 98. Therefore, according to the present embodiment, a relay 10 can be provided that can secure a relatively long insulation distance between the coil terminal 28 and the fixed terminal 36 without increasing the size or the number of parts.

[0036] As shown in FIG. 18, the wall portion 98 may have a tapered guide portion 100 that facilitates the insertion of the fixed terminal 36 during the assembly of the relay 10. The guide portion 100 also has a function of improving the positioning accuracy of the fixed terminal 36.

[0037] In the above description, the relay 10 having a so-called 1c contact structure with a break terminal 32 having a fixed contact has been described, but the application target of the present disclosure is not limited to this. For example, the present disclosure can be similarly applied to a relay having a so-called 1a contact structure having a backstop 104 without a fixed contact instead of a break terminal, such as the relay 10' shown in FIG. 19.

Explanation of Reference Numerals

[0038] 10, 10' Relay, 12 Base, 14 Bobbin, 16 Coil, 18 Core, 20 Electromagnet, 22 Armature, 24 Movable Contact, 25 Pole Piece, 26 Movable Terminal, 28 Coil Terminal, 38 Cover, 40 Insulating Member, 42 Wall Portion, 44 Fitting Portion, 46 Flange Portion, 47 Barrel Portion, 48 Lower Flange Portion, 50 Upper Flange Portion, 52 Overhanging Portion, 54 Bottom Portion, 56 Rib, 58 Tapered Portion, 60 Relief Portion, 62 Movable Spring, 64 Recess, 66 Extension Portion, 76, 78 Tapered Portions, 80, 82 Step Portions, 84 Wall Portion, 86 Frame Portion, 88 Opening, 90 Bottom Portion, 92, 94, 96 Holes, 98 Wall Portion, 100 Guide Portion, 104 Backstop

Claims

1. An electromagnetic relay having a coil, a bobbin around which the coil is wound, an iron core inserted into the bobbin, an armature that cooperates with the iron core to form a magnetic circuit, a movable terminal having a movable contact that operates with the operation of the electromagnetic relay, a fixed terminal having a fixed contact disposed opposite to the movable contact, a coil terminal attached to the bobbin and connected to the coil, an insulating member disposed between the coil and the armature, a base having a wall portion that insulates between the coil terminal and the fixed terminal, and comprising.

2. The electromagnetic relay according to claim 1, wherein the insulating member has a fitting portion that fits with a lower flange portion of the bobbin, and the insulating member contacts the bobbin only at the fitting portion.

3. The electromagnetic relay according to claim 2, wherein at least one of an upper flange portion and a lower flange portion of the bobbin has a stepped portion extending toward the armature.

4. The electromagnetic relay according to claim 2, wherein a portion constituting the fitting portion of the insulating member has a constant wall thickness.

5. The electromagnetic relay according to claim 1, wherein the insulating member has an overhanging portion extending in a substantially tangential direction of the coil, and a side of the overhanging portion facing the armature has a concave portion.

6. The electromagnetic relay according to claim 1, wherein an upper end surface of the insulating member in the axial direction of the iron core is located on the side opposite to the contact side in the axial direction of the iron core, relative to an upper end of the bobbin.

7. The electromagnetic relay according to claim 1, wherein a lower end surface of the insulating member in the axial direction of the iron core is located on the contact side in the axial direction of the iron core, relative to a lower end of the bobbin.

8. The electromagnetic relay according to claim 1, wherein the insulating member has an overhanging portion extending in a substantially tangential direction of the coil, and a lower end of the overhanging portion has a tapered shape that narrows toward the iron core in a direction perpendicular to the axial direction of the iron core.

9. The electromagnetic relay according to claim 1, wherein the insulating member has a eaves portion that covers an upper flange portion of the bobbin and does not contact the upper flange portion.

10. The electromagnetic relay according to claim 9, wherein the eaves portion has a tapered shape that tapers toward the iron core.

11. The electromagnetic relay according to claim 1, wherein the wall portion of the base is formed adjacent to a hole for the fixed terminal formed in the base.

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