relay

Abstract

To provide a relay with shock resistance and easy to assemble.SOLUTION: A base 48 has a leg 80 extending a contact direction, and the leg 80 is configured to come into contact with a yoke 72 when the base 48 is assembled within a case 22. The leg 80 is arranged with a spaced above an armature 60. The space is set to a value such that, in the normal operation of armature 60, the top surface of armature 60 does not come into contact with the leg 80, but when a vehicle equipped with a relay 10 receives a strong impact and when armature 60 jumps beyond its range of motion, the upper surface of the armature 60 comes into contact with the lower surface of leg 80.SELECTED DRAWING: Figure 11

Description

Technical Field

[0001] The present invention relates to a relay.

Background Art

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

[0003] In recent years, the use of relays in applications that are likely to be subjected to impacts and vibrations such as being mounted on electric vehicles has been increasing. In order to prevent displacement of the armature with respect to the yoke when a large impact or vibration is applied to the relay, a technique is known in which a shaft portion is provided on one of the yoke or the armature, and a bearing for rotatably receiving the shaft portion is provided on the other, making the armature rotatable with respect to the yoke.

[0004] An assembly structure of a relay is known in which a contact holder groove opened on the side surface of an insulating substrate is formed, a fixed contact and a movable contact are inserted into the holding groove and locked and held, and then the periphery of the lead-out portion of an external terminal is sealed with an adhesive. A relay terminal block is known in which a groove for mounting parts with an open side surface is provided in a body, parts such as terminal parts are inserted through the opening and attached to the body, and a cover plate covering the opening is attached to the body.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

[0006] Many relays use leaf springs or coil springs to generate the appropriate contact and release forces for opening and closing the contacts. When such relays are used in applications that are susceptible to shock and vibration, the springs may plastically deform due to the shock, potentially resulting in an inability to obtain the appropriate contact and release forces. On the other hand, if additional reinforcing members are added to withstand the shock, the assembly process of the relay becomes more complicated, which can lead to increased costs.

[0007] Therefore, the present invention aims to provide a relay that is resistant to shocks and vibrations and easy to assemble. [Means for solving the problem]

[0008] One aspect of the present disclosure comprises an electromagnet, a movable contact portion having a movable contact that operates in conjunction with the operation of the electromagnet, and a fixed contact portion having a base to which a fixed contact is mounted, the base comprising a permanent magnet, a yoke and Stretch out the generated arc Arc extinguishing plate is attached. The arc-extinguishing plate is mounted on the base so as to extend toward the fixed contact. It's a relay race. [Effects of the Invention]

[0009] According to this disclosure, by configuring the legs of the base to which the fixed terminals are attached to extend in the direction of contact and separation between the fixed contact and the movable contact, abut against the yoke, and be positioned above the armature at a predetermined distance, it is possible to improve the positioning accuracy between the fixed contact and the electromagnet, as well as prevent damage or plastic deformation of each part due to impact or the like. [Brief explanation of the drawing]

[0010] [Figure 1] This is an assembly diagram of the relay according to the embodiment. [Figure 2] Figure 1 is an exploded perspective view of the relay. [Figure 3] This is a perspective view of the case. [Figure 4]It is a view of the case of FIG. 3 seen from the front. [Figure 5] It is a cross-sectional view showing the positional relationship of the ribs, yoke, and amateur in the case. [Figure 6] It is a rear view of the case. [Figure 7] It is a view showing the state where the opening of the case of FIG. 6 is blocked with resin. [Figure 8] It is an exploded perspective view of the fixed contact portion and the movable contact portion. [Figure 9] It is a view showing the exploded perspective view of the electromagnet together with the case. [Figure 10] [[ID= eighteen]]It is a top view of the fixed contact portion and the movable contact portion. [Figure 11] It is a side view of the fixed contact portion and the movable contact portion. [Figure 12] It is a perspective view of the base of the fixed contact portion. [Figure 13] It is a cross-sectional view taken along the line B-B′ of FIG. 10. [Figure 14] It is a side cross-sectional view of the movable contact portion and the electromagnet, showing the state where the contacts are open. [Figure 15] It is a perspective view of the return spring post. [Figure 16] It is a perspective view of the movable spring. [Figure 17] It is a side cross-sectional view of the movable contact portion and the electromagnet, showing the state where the contacts are closed. [Figure 18] It is a perspective view of the base of the fixed contact portion. [Figure 19] It is a view showing a permanent magnet and an arc extinguishing plate attached to the base of FIG. 18. [Figure 20] It is a view showing the configuration of FIG, 19 with the base removed. [Figure 21] It is a view showing how the arc is extended by the arc extinguishing plate. [Figure 22] As a comparative example of FIG. 21, it is a view showing the case where there is no arc extinguishing plate. <00​​​This figure is similar to Figure 20, but shows the case where a magnetic shield is provided. [Figure 25] This diagram illustrates the magnetic flux when a magnetic shield is installed. [Figure 26] Figure 25 illustrates the case without magnetic shielding as a comparative example. [Modes for carrying out the invention]

[0011] Figures 1 and 2 are an assembly drawing and an exploded perspective view of a relay (electromagnetic relay) 10 according to an embodiment, respectively. The relay 10 is a relay for on-board electrical equipment used, for example, in an electric vehicle. The relay 10 is a hinged relay having a fixed contact section 14 with a fixed contact 12 (see Figure 8), a movable contact section 18 with a movable contact 16, an electromagnet 20 that displaces the movable contact 16 so that it can move toward and away from the fixed contact 12, and a case 22 that houses the movable contact section 18 and the electromagnet 20. The relay 10 is mounted on a printed circuit board or the like (not shown) using a metal collar 24 attached to the outside of the case 22 by crimping or the like.

[0012] As shown in Figure 2, the movable contact portion 18 and the electromagnet 20 (collectively referred to as the "body 21" of the relay) are inserted into the case 22 by moving them along the direction of contact and separation between the fixed contact 12 and the movable contact 16 (approximately left-right direction in Figure 2). Therefore, the case 22 can have a structure that opens only in the contact and separation direction, and does not need to have a structure that combines parts divided into two in the vertical direction, for example. The fixed contact portion 14 includes a base 48 and a fixed contact 12 provided on the base 48. By inserting the fixed contact portion 14 into the case 22, the back of the fixed contact portion 14 forms the cover of the relay 10. The relay 10 is sealed by filling the boundary between the fixed contact portion 14 and the case 22 with resin or adhesive. The case 22 can be manufactured, for example, from resin molding. By forming the case 22 as described above, the number of parts can be reduced and manufacturing costs can be lowered.

[0013] Figures 3 and 4 are a perspective view and a front view, respectively, showing the interior of the case 22. The case 22 has ribs 26 and 28 for guiding and positioning the movable contact portion 18 and the electromagnet 20 to predetermined positions within the case 22. Each rib extends in the direction of contact and separation of the contacts, and in the direction of mounting the main body 21 to the case 22.

[0014] Figure 5 is a schematic cross-sectional view showing the positional relationship of the components of the electromagnet 20, namely the armature 60, yoke 72, and each rib, when the electromagnet 20 is placed in the case 22. The rib 26 formed on the inner bottom surface of the case 22 abuts against the lower surface of the yoke 72, supporting the movable contact portion 18 and contributing to the vertical positioning of the movable contact portion 18. The rib 28 formed on the inner surface of the case 22 has an inclined surface 29 that slopes in the direction of insertion of the main body 21, and the inclined surface 29 functions as a guide in the width direction of the yoke 72 when the main body 21 is inserted into the case 22. After the insertion of the main body 21, the rib 28 abuts against the side surface of the yoke 72, contributing to the precise positioning of the electromagnet 20 in the width direction relative to the case 22.

[0015] The rib 30 formed on the upper surface inside the case 22 is positioned at a vertical distance from the armature 60 and does not come into contact with the armature 60 during normal operation. However, even if the armature 60 jumps up significantly beyond its range of motion due to a strong impact on the vehicle on which the relay 10 is mounted, the movement of the armature 60 is restrained by the rib 30, preventing large forces from acting on the contacts and the return spring described later. Therefore, by providing the rib 30, damage to various parts and plastic deformation of the spring can be prevented.

[0016] Figure 6 shows the rear side of the case 22, that is, the side opposite to the opening into which the main body 21 is inserted. As shown in Figures 2 and 9, the electromagnet 20 has two coil terminals 78 for supplying power to the coil 68. The coil terminals 78 are inserted into a vertically elongated opening 41 (see Figures 3 and 4) formed inside the case 22 and are exposed to the outside of the case 22 through an opening 32 formed on the rear side of the case 22. The opening 32 has space for routing electric wires 34 and 36 connected to the two coil terminals 78, respectively. The electric wires 34 and 36 are introduced into a pocket 38 formed on the outside of the case 22, then pulled out through an opening 40 of the pocket 38 that opens upwards, and electrically connected to a printed circuit board (not shown) on which the relay 10 is mounted.

[0017] Figure 7 shows the state after the wires 34 and 36 have been pulled out from the opening 40 and the opening 32 has been filled and sealed with resin or adhesive 42. In this way, the back of the case 22 does not have the wires 34 and 36 or related components protruding, and therefore a compact relay can be constructed in terms of the contact direction. It is preferable to provide an air hole 44 in the case 22 to release the air that has expanded inside the case 22 when thermosetting resin or adhesive is used. It is preferable that the air hole 44 be sealed with resin or the like after the opening 32 has been sealed.

[0018] Figure 8 is an exploded perspective view of the fixed contact section 14 and the movable contact section 18. The fixed contact section 14 has at least one (two in the illustrated example) fixed terminals 46, each equipped with a fixed contact 12, and a frame-shaped or box-shaped base 48 to which the fixed terminals 46 are attached. Resin or adhesive is filled between the fixed terminals 46 and the base 48 to seal the gap. The base 48 is manufactured, for example, by resin molding. A permanent magnet 50 and a permanent magnet yoke 54 are attached to the outer surface of the base 48, and an arc extinguishing plate 52 for extinguishing arcs is inserted into the base 48, but these will be described later.

[0019] The movable contact portion 18 includes a conductive plate 56 to which the movable contact 16 is attached by crimping or the like, a movable spring 58 to which the conductive plate 56 is attached, and an armature 60 to which the movable spring 58 is attached by rivets 62 or the like.

[0020] Figure 9 shows an exploded perspective view of the electromagnet 20 along with the case 22. The electromagnet 20 includes a bobbin 70, an iron core 66 placed inside the bobbin 70, a coil 68 wound around the bobbin 70, a roughly L-shaped yoke 72 to which the lower end of the iron core 66 is connected, and a spring post 74 attached to the yoke 72. The bobbin 70 has a terminal opening 76 into which the coil terminal 78 is inserted, and current flows to the coil 68 via the electric wires 34, 36 and the coil terminal 78. The armature 60 is pivotably supported relative to the yoke 72. As will be described later, the movable spring 58 and the spring post 74 are elastically displaceable from each other via a return spring 64 (see Figure 8).

[0021] Figures 10 and 11 are top and side views of the fixed contact portion 14 and the movable contact portion 18, respectively, and Figure 12 is a perspective view of the base 48. The base 48 has legs 80 that extend in the direction in which the main body is mounted to the case 22. As shown in part A of Figures 10 and 11, the end faces of the legs 80 are configured to abut the yoke 72 when the base 48 is assembled into the case 22. Thus, the positional relationship of the contacts between the fixed contact portion 14 and the electromagnet 20 in the direction of contact and separation is uniquely determined, and accurate positioning between each component in the case 22 is possible.

[0022] As can be seen from Figure 13, which shows the BB' cross-section of Figure 10, the leg portion 80 is positioned above the armature 60, spaced apart from the armature 60. This spacing is set such that under normal operation, the upper surface of the armature 60 does not contact the lower surface of the leg portion 80, but when the vehicle on which the relay 10 is mounted is subjected to a strong impact, causing the armature 60 to spring up beyond its range of motion, the upper surface of the armature 60 will contact the lower surface of the leg portion 80. Conventional relays do not have a member to suppress large displacements caused by the lifting of the armature 60, so the displacement of the armature 60 can exert a large force in the direction that stretches the return spring 64, which may cause the return spring 64 to undergo plastic deformation. In this embodiment, the leg portion 80 suppresses movement of the armature 60 beyond its normal range of motion, reducing the force on the contacts and the return spring 64, and preventing plastic deformation of the return spring 64. In other words, the leg portion 80 not only improves the positioning accuracy between the fixed contact portion 14 and the electromagnet 20, but also has the function of preventing damage and plastic deformation of various parts due to impact, etc. The leg portion 80 can be integrally molded with the base 48 by resin molding, etc., and in such a case, there is no increase in the number of parts.

[0023] Figure 14 is a side cross-sectional view of the movable contact portion 18 and the electromagnet 20, Figure 15 is a perspective view showing an example of the structure of the spring post 74, and Figure 16 is a perspective view showing an example of the structure of the movable spring 58. The return spring 64 shown in Figure 14 is a coil spring, but it may be made of a leaf spring or the like. One end of the return spring 64 is held by engaging with a recess 86 formed at the base of a tip portion 84 formed approximately in the widthwise center of the spring post 74, which is fixed to the yoke 72. The other end of the return spring 64 is held by engaging with a recess 94 formed at the base of a projection 92 formed on the movable spring 58. When the electromagnet 20 is off, the biasing force of the return spring 64 causes the armature 60 to tilt away from the iron core 66, and the movable contact 16 is separated from the fixed contact 12 (Figure 14). On the other hand, as shown in Figure 17, when the electromagnet 20 is on, the armature 60 is displaced toward the iron core 66 by magnetic force against the biasing force of the return spring 64, and the movable contact 16 comes into contact with the fixed contact 12.

[0024] If a strong impact or external force acts on the relay 10 in the direction of separation of the movable contact 16 (left-right direction in Figure 14), the movable contact 16 and conductive plate 56 will be displaced significantly toward the yoke 72, and as a result, the movable spring 58 may undergo plastic deformation. In this embodiment, this problem can be prevented by extending the tip portion 84 of the spring post 74 toward the movable contact side in the direction of contact separation beyond the yoke 72. Even if the movable contact 16 is displaced toward the yoke 72 side due to impact or the like, the movable spring 58 or conductive plate 56 will abut against the tip portion 84, suppressing further displacement of the movable spring 58 and preventing damage or plastic deformation of the movable spring 58. Furthermore, since the tip portion 84 is provided on the return spring post for attaching the return spring, there is no need to provide a separate member to suppress the displacement of the movable spring, and the number of parts can be reduced.

[0025] In the case of a relay in which one end of the return spring is directly engaged with the yoke 72, there is no member interposed between the conductive plate and the yoke, so it is not possible to prevent the conductive plate from being displaced significantly toward the yoke. However, the spring post 74 in this embodiment has a tip portion 84 that suppresses the lateral displacement of the conductive plate 56 in addition to the function of holding the return spring 64, and thus has the function of preventing plastic deformation of the movable spring 58 due to large external forces in the contact separation direction.

[0026] When miniaturization of the relay is required, it is preferable that the distance between the yoke 72 and the conductive plate 56 be short. In this embodiment, as shown in Figure 9 or Figure 14, a recess or opening 96 is formed in the yoke 72, and a part of the spring post 74 is positioned within the opening 96. As shown in Figure 15, the spring post 74 has a base 87 fixed to the yoke 72, a first bent portion 88 that bends in a direction extending from the base 87 into the opening 96, and a second bent portion 90 that bends from the first bent portion 88 in the opposite direction to the bending direction of the first bent portion 88, with the tip portion 84 provided on the second bent portion 90. By configuring the spring post 74 so that a part of it is positioned within the opening 96, the distance that the spring post 74 extends from the yoke 72 towards the movable contact 16 can be minimized, thereby enabling miniaturization of the relay. Furthermore, since the spring post 74 has two bent portions 88 and 90 that bend in opposite directions, it is possible to elastically deform it in the direction of contact and separation of the contact points, thereby preventing damage and plastic deformation of the spring post 74.

[0027] If vibrations with a frequency equal to the natural frequency of the movable part of a hinged relay are applied to the relay, resonance may occur in the movable part. For example, if vibrations with a frequency equal to the natural frequency of the movable contact part 18 are applied to the relay 10, resonance will occur in the movable contact 16 in the direction of contacting and separating from the fixed contact 12, which may lead to malfunction of the relay 10, such as the movable contact 16 coming into contact with the fixed contact 12 in an unintended situation.

[0028] Therefore, in this embodiment, when the movable contact 16 is in the neutral position as shown in Figure 14 (when the relay 10 is not operating), the distance d1 in the contact-to-separation direction between the tip portion 84 and the movable spring 58 or conductive plate 56 is set to be smaller than the distance d2 between the fixed contact 12 and the movable contact 16 (see Figure 14). Because d1 is smaller than d2, even if the movable contact portion 18 vibrates due to resonance, the movable spring contacts the return spring post before the amplitude becomes large, thereby preventing the amplitude from increasing further. As a result, it is possible to prevent the fixed contact 12 and the movable contact 16 from unintentionally coming into contact due to resonance. Thus, the spring post 74 having the above-described dimensional relationship can prevent malfunction of the relay when the movable part resonates.

[0029] In relays, especially DC relays that handle high voltages such as 400-800V, means of extending or extinguishing the arc to protect the contacts are provided, specifically permanent magnets or arc extinguishing plates. Because these means were attached to components separate from the arc extinguishing chamber, which has the arc extinguishing function, they increased component costs and assembly man-hours.

[0030] Therefore, in this embodiment, as shown in Figures 8 and 18, the base 48 is formed in a frame or box shape by resin molding or the like, and the base 48 has a recess 100 on the side into which the permanent magnet 50 is fitted, a slot 102 into which the arc extinguishing plate 52 is inserted, and an outer surface 104 to which the permanent magnet yoke 54 is attached. The base 48 shown in Figure 8 and the like is integrally molded.

[0031] Figure 19 shows the permanent magnet 50, arc extinguishing plate 52, and yoke 54 attached to the base 48, while Figure 20 shows the same configuration as in Figure 19 but with the base 48 omitted for clarity. In this way, the yoke 54, permanent magnet 50, and arc extinguishing plate 52 can all be attached to the base 48 to which the fixed contact 12 is mounted. Therefore, the base 48 also functions as an arc extinguishing chamber with high arc interruption performance, having the permanent magnet 50, yoke 54, and arc extinguishing plate 52 surrounding the fixed contact 12.

[0032] Figure 21 is a side cross-sectional view of the base 48, illustrating how the arc is stretched and extinguished by the permanent magnet 50, arc extinguishing plate 52, and yoke 54. The magnetic flux from the permanent magnet 50 and yoke 54 stretches the arc 106 generated between the fixed contact 12 and the movable contact 16 into the arc extinguishing chamber of the base 48. Preferably, the two permanent magnets 50 have the same polarity on their opposing surfaces, and this same-polarity opposing arrangement allows the arcs generated between each contact to be stretched in the same direction.

[0033] Figure 22 shows the state of the arc without the arc extinguishing plate 52 as a comparative example. As can be seen from Figure 21, the arc 106 is stretched by the arc extinguishing plate 52 inserted into the base 48. On the other hand, in Figure 22, where the arc extinguishing plate 52 is not provided, the arc spreads within the base 48 without being stretched. In this way, by mounting all the components related to arc extinguishing on the base 48, which has space reserved for arc extinguishing, a relay with high arc interruption capability is provided without increasing the number of parts.

[0034] This embodiment is a so-called double-break relay, and since two fixed contacts 12 are attached to the base 48, it is preferable to place permanent magnets and arc-extinguishing plates as close as possible to each fixed contact. In this embodiment, two permanent magnets 50 are attached to both sides of the base 48, and two arc-extinguishing plates 52 are inserted and positioned in the base 48 so that they extend as close as possible to the two fixed contacts 12. The yoke 54 is configured to be divided into two parts vertically for ease of assembly and so that it can be attached to the base 48 from the top and bottom directions, but it is not limited to this configuration. For example, it may be divided into two parts horizontally so that it can be attached to the base 48 from the left and right directions.

[0035] Figure 23 is an exploded perspective view of the fixed contact section 14'. The fixed contact section 14' differs from Figure 8 in that a magnetic shield 110 made of a highly permeable material such as iron is positioned between the two fixed contacts 12 at a fixed location (the base 109 of the base 48 in the illustrated example). The other components are the same as in Figure 8, and the same reference numerals are used, so detailed explanations are omitted.

[0036] Figure 24 shows the configuration without the base 48. Figure 24 shows the permanent magnet 50, the arc extinguishing plate 52, the yoke 54, and the magnetic shield 110 positioned between the two fixed contacts 12. In this embodiment, in addition to the arc extinguishing function, the magnetic flux absorption function described below is also obtained.

[0037] Figure 25 illustrates the relationship between the current flowing through the fixed contact 12 and the magnetic flux, while Figure 26 shows the relationship between the current and magnetic flux in the absence of the magnetic shield 110 as a comparative example. For example, when the relay is used as a DC relay, the current input to one fixed terminal 46 in the direction of arrow 112 flows through the fixed contact 12, the movable contact 16, the conductive plate 56, and the other fixed contact 12, and then flows from the other fixed terminal 46 in the direction of arrow 114. This current creates a magnetic flux 116 between the two fixed contacts 12 and fixed terminals 46, perpendicular to the plane of the paper and directed from back to front. When a large current is passed through the closed contacts of the relay, an electromagnetic repulsive force is generated between the movable contact and the fixed contact, which may cause the contacts to separate or even weld together.

[0038] If the magnetic shield 110 is not provided as shown in Figure 26, the influence of the magnetic flux 116 extends to the area indicated by the dashed line 120, for example. Therefore, a Lorentz force acts on the conductive plate 56 within the area 120 in the direction indicated by the arrow 122. Consequently, in the example of Figure 26, a force in the direction of contact separation is applied to the conductive plate 56, and there is a risk that the fixed contact 12 and the movable contact 16 will separate due to the Lorentz force.

[0039] In contrast, when a magnetic shield 110 is provided as shown in Figure 25, the magnetic flux is absorbed by the magnetic shield 110, thus preventing a force from being generated on the conductive plate 56 in the direction of contact separation due to the influence of the magnetic flux. Therefore, according to this embodiment, a relay that is less prone to malfunction is provided, especially when a large current is flowing.

[0040] The magnetic shield 110 is placed on a fixed part of the relay 10, such as the base 48, rather than on the movable part. While it is possible to place the magnetic shield on the movable part, generally, an increase in the weight of the movable part tends to make the relay more prone to malfunction when subjected to shock or other impacts. Therefore, it is preferable to avoid placing the magnetic shield on the movable part. In this embodiment, since the magnetic shield is placed on a fixed part, the weight of the movable part does not increase due to the magnetic shield, and such problems can be prevented. [Explanation of Symbols]

[0041] 10 Relay, 12 Fixed contact, 14 Fixed contact section, 16 Movable contact, 18 Movable contact part, 20 Electromagnet, 22 Case, 26, 28, 30 Ribs, 32 openings, 34, 36 wires, 38 pockets, 40 openings, 42 Adhesive, 46 Fixing terminal, 48 Base, 50 Permanent magnet, 52 Arc extinguishing plate, 54 Permanent magnet yoke, 56 Conductive plate, 58 Movable spring, 60 Armor, 64 return spring, 72 yoke, 74 spring post, 78 coil terminal, 80 legs, 84 tips, 88,90 bends, 92 protrusions, 96 openings, 106,108 Arc, 109 Base, 110 Magnetic Shield

Claims

1. Electromagnets and, A movable contact section having a movable contact that operates in conjunction with the operation of the electromagnet, A fixed contact portion having a base to which a fixed contact is attached, which is positioned opposite the movable contact, A relay comprising a base on which a permanent magnet, a yoke, and an arc-extinguishing plate for extending the generated arc are mounted, the arc-extinguishing plate being mounted on the base so as to extend toward the fixed contact.

2. The relay according to claim 1, wherein a magnetic shield is attached to the base.

3. The relay according to claim 1, wherein the yoke is attached to the base so as to surround the base and the arc extinguishing plate.

4. The relay according to claim 3, wherein the yoke is divided and attached to the base.

5. The relay according to claim 3, wherein the base has an annular outer surface to which the yoke is attached.

6. The relay according to claim 1 or 2, wherein the base has a slot into which the arc extinguishing plate is inserted.

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