The present invention relates to an electromagnetic relay.
In an electromagnetic relay, an arc may occur between contacts. In that case, the arc shortens the mechanical life of the electromagnetic relay. Therefore, for example, the electromagnetic relay disclosed in Japan Laid-open Patent Application Publication No. 2012-256451 includes an arc guide (arc runner). The arc guide is connected to a movable contact piece and extends away from the fixed terminal. The arc generated between the contacts is quickly extinguished by extending along the arc guide.
In the above electromagnetic relay, the arc guide is used only for arc extension. On the other hand, in an electromagnetic relay, when a high-capacity current is applied, the terminal may generate heat and become hot. In that case, the substrate or the electromagnetic relay itself may be damaged by the heat from the terminal. An object of the present disclosure is to quickly extinguish an arc and reduce heat generation at a terminal in an electromagnetic relay.
An electromagnetic relay according to one aspect of the present disclosure includes a housing, a fixed contact, a fixed terminal, and a movable contact. The fixed contact is disposed in the housing. The movable contact is disposed in the housing and faces the fixed contact. The fixed contact is connected to the fixed terminal. The fixed terminal includes a contact support portion, a first arc guide, and a second arc guide. The contact support portion supports the fixed contact. The first arc guide extends from the contact support portion. The first arc guide includes a tip that projects outward of the housing. The first arc guide is disposed in the housing to extend an arc generated at the fixed contact. The second arc guide extends from the contact support portion. The second arc guide includes a tip that projects outward of the housing. The second arc guide is disposed in the housing to extend the arc generated at the fixed contact.
In the electromagnetic relay according to the present embodiment, the arc generated at the contact is extended along the first arc guide or the second arc guide. Thereby, the arc can be extinguished quickly. Further, the tips of the first arc guide and the second arc guide project outward from the housing and are used as external terminals. Therefore, the current flows separately in the first arc guide and the second arc guide. Thereby, heat generation in each of the first arc guide and the second arc guide can be reduced. Further, the heat generated at the contact can be transmitted to the outside of the electromagnetic relay via a plurality of paths.
The electromagnetic relay may further include a magnet. The magnet may be disposed so that a starting point of the arc generated at the fixed contact is moved at least in a predetermined direction by a magnetic force. The first arc guide may be connected to the contact support portion at a position in the predetermined direction with respect to the fixed contact. The second arc guide may be connected to the contact support portion at a position in an opposite direction to the predetermined direction with respect to the fixed contact. In this case, the arc can be effectively extended by the first arc guide or the second arc guide.
The starting point of the arc generated at the fixed contact may be moved at least in a predetermined direction by a self-magnetic field generated from the current flowing through the fixed contact. The first arc guide may be connected to the contact support portion at a position in the predetermined direction with respect to the fixed contact. The second arc guide may be connected to the contact support portion at a position in an opposite direction to the predetermined direction with respect to the fixed contact. In this case, the arc can be effectively extended by the first arc guide or the second arc guide.
The fixed terminal may have a bent shape between the first arc guide and the contact support portion. The fixed terminal may have a bent shape between the second arc guide and the contact support portion.
The fixed contact may be joined to the contact support portion by fused bonding. In this case, even if the first arc guide and the second arc guide are disposed near the contacts, the fixed contact can be easily joined to the contact support portion. Alternatively, the fixed contact may be joined to the contact support portion by caulking.
The first arc guide and the second arc guide may be joined to each other at least outside of the housing. In this case, the first arc guide and the second arc guide can be easily attached to an external electronic circuit such as a substrate.
The first arc guide and the second arc guide may be disposed to be inclined so that a distance between the first arc guide and the second arc guide increases toward a direction away from the fixed contact. In this case, the movement of the starting point of the arc can be controlled by the inclination of the first arc guide and the second arc guide.
The first arc guide and the second arc guide may be disposed to be inclined so that a distance between the first arc guide and the second arc guide becomes smaller toward a direction away from the fixed contact. In this case, the movement of the starting point of the arc can be controlled by the inclination of the first arc guide and the second arc guide.
The first arc guide may include a step portion disposed in the housing. In this case, the movement of the starting point of the arc can be restricted by the step portion. Thereby, it is possible to prevent the arc from leaking to the outside of the housing along the first arc guide.
Hereinafter, an embodiment of an electromagnetic relay 1 according to one aspect of the present invention will be described with reference to the drawings.
When referring to the drawings, the upper side in
The housing 2 is made of an insulating material such as resin. However, the housing 2 may be made of another material such as ceramic. The contact device 3 is housed in the housing 2.
The contact device 3 includes a first fixed terminal 6, a second fixed terminal 7, a movable contact piece 8, and a movable mechanism 9. The first fixed terminal 6 and the second fixed terminal 7 extend in the moving direction of the movable contact piece 8. The first fixed terminal 6 and the second fixed terminal 7 are disposed so as to be spaced apart from each other in the left-right direction. A first fixed contact 10 is connected to the first fixed terminal 6. A second fixed contact 11 is connected to the second fixed terminal 7. The first fixed contact 10 and the second fixed contact 11 are disposed in the housing 2.
The movable contact piece 8 extends in the left-right direction. The movable contact piece 8 is disposed in the housing 2. A first movable contact 12 and a second movable contact 13 are connected to the movable contact piece 8. The first movable contact 12 faces the first fixed contact 10. The second movable contact 13 faces the second fixed contact 11. The first movable contact 12 is disposed at a distance from the second movable contact 13 in the left-right direction.
The movable contact piece 8 is movable in a contact direction and an opening direction. The contact direction is a direction in which the movable contacts 12 and 13 approach the fixed contacts 10 and 11. The opening direction is a direction in which the movable contacts 12 and 13 are separated from the fixed contacts 10 and 11. In the present embodiment, the movable contact piece 8 is movable in the vertical direction.
The movable mechanism 9 supports the movable contact piece 8. The movable mechanism 9 is configured to move between a closed position and an open position. When the movable mechanism 9 is in the closed position, the fixed contacts 10 and 11 and the movable contacts 12 and 13 contact each other. When the movable mechanism 9 is in the open position, the fixed contacts 10 and 11 and the movable contacts 12 and 13 are separated from each other. The movable mechanism 9 includes a drive shaft 15 and a contact spring 16. The drive shaft 15 is connected to the movable contact piece 8. The drive shaft 15 extends in the vertical direction and extends through the movable contact piece 8 in the vertical direction. The drive shaft 15 is configured to move in the vertical direction. The contact spring 16 urges the movable contact piece 8 in the contact direction.
The drive device 4 includes a coil 21, a spool 22, a movable iron core 23, a fixed iron core 24, a yoke 25, and a return spring 26. The drive device 4 moves the movable contact piece 8 in the contact direction and the opening direction via the movable mechanism 9 by an electromagnetic force. The coil 21 is wound around the spool 22. The movable iron core 23 and the fixed iron core 24 are disposed in the spool 22. The movable iron core 23 is connected to the drive shaft 15. The movable iron core 23 is movable in the vertical direction. The fixed iron core 24 is disposed so as to face the movable iron core 23. The return spring 26 urges the movable iron core 23 in the opening direction.
In the electromagnetic relay 1 according to the present embodiment, when the coil 21 is energized, the movable iron core 23 is attracted to the fixed iron core 24 by the magnetic force generated by the magnetic field generated from the coil 21. As a result, the movable iron core 23 and the drive shaft 15 move in the contact direction against the urging force of the return spring 26. As a result, the movable contact piece 8 and the movable contacts 12 and 13 move in the contact direction, and the movable contacts 12 and 13 contact the fixed contacts 10 and 11. After the movable contacts 12 and 13 contact the fixed contacts 10 and 11, the drive shaft 15 further moves in the contact direction, so that the contact spring 16 is compressed.
When the energization to the coil 21 is turned off, the movable iron core 23 and the drive shaft 15 move in the opening direction by the urging force of the return spring 26. As a result, the movable contact piece 8 and the movable contacts 12 and 13 move in the opening direction, and the movable contacts 12 and 13 are separated from the fixed contacts 10 and 11.
As shown in
As shown in
In
The first arc guide 32 has a plate-like shape. The first arc guide 32 extends upward from the first contact support portion 31. The first arc guide 32 is connected to the contact support portion 31 at a position disposed in the direction of the first Lorentz force F1 with respect to the first fixed contact 10. As shown in
The second arc guide 33 has a plate-like shape. The second arc guide 33 extends upward from the contact support portion 31. The second arc guide 33 is connected to the contact support portion 31 at a position disposed in the direction of the second Lorentz force F2 with respect to the first fixed contact 10. As shown in
The first fixed terminal 6 has a bent shape between the first arc guide 32 and the contact support portion 31. The first fixed terminal 6 has a bent shape between the second arc guide 33 and the contact support portion 31. Therefore, the first fixed terminal 6 has a U-shaped bent shape.
The tip 34 of the first arc guide 32 projects outward of the housing 2. The tip 35 of the second arc guide 33 projects outward of the housing 2. The tip 34 of the first arc guide 32 and the tip 35 of the second arc guide 33 are used as external terminals. That is, the tip 34 of the first arc guide 32 and the tip 35 of the second arc guide 33 are electrically connected to an external electronic circuit. For example, the tip 34 of the first arc guide 32 and the tip 35 of the second arc guide 33 are connected to a substrate. Alternatively, the tip 34 of the first arc guide 32 and the tip 35 of the second arc guide 33 may be connected to an electric wire or a bus bar.
The second fixed terminal 7 has the same shape as the first fixed terminal 6. As shown in
In the electromagnetic relay 1 according to the present embodiment described above, the arcs generated at the fixed contact 10 are extended along the first arc guide 32 or the second arc guide 33. Thereby, the arc can be extinguished quickly. Further, the tip 34 of the first arc guide 32 and the tip 35 of the second arc guide 33 project to the outside from the housing 2 and are used as external terminals. Therefore, the current flows separately in the first arc guide 32 and the second arc guide 33. Thereby, heat generation in each of the first arc guide 32 and the second arc guide 33 can be reduced. Further, the heat generated by the fixed contact 10 can be transmitted to the outside of the electromagnetic relay via a plurality of paths.
Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the invention. The configuration of the contact device is not limited to that of the above embodiment, and may be changed.
For example, the shape of the movable contact piece 8 may be changed. The first movable contact 12 and the second movable contact 13 may be integrated with the movable contact piece 8. The first fixed contact 10 may be integrated with the first fixed terminal 6. The second fixed contact 11 may be integrated with the second fixed terminal 7. The number of movable contacts is not limited to two, and may be more than two. The number of fixed contacts is not limited to two, and may be more than two. The configuration of the movable mechanism 9 is not limited to that of the above embodiment, and may be changed. The configuration of the drive device 4 is not limited to that of the above embodiment, and may be changed.
The arrangement of the magnets 27 and 28 or the arrangement of the magnetic field by the magnets 27 and 28 may be changed. For example,
Alternatively, the arrangement of the first arc guide 32 and the second arc guide 33 may be changed. For example,
The shapes of the first arc guide 32 and the second arc guide 33 may be changed. The first arc guide 32 and the second arc guide 33 may include a step portion disposed in the housing 2. For example,
The first arc guide 32 and the second arc guide 33 may be disposed so as to be inclined with respect to the vertical direction. For example,
The first arc guide 32 and the second arc guide 33 may include a bent portion. For example,
The first arc guide 32 and the second arc guide 33 may be joined to each other at least outside of the housing 2.
The number of arc guides of the first fixed terminal 6 is not limited to two. The number of arc guides of the first fixed terminal 6 may be one or more than two. For example,
The width of the arc guide may be different from the width of the contact support portion 31. The width means a dimension in the direction perpendicular to the direction in which the starting point of the arc moves in the first fixed terminal 6. For example,
The electromagnetic relay 1 according to the above embodiment is a so-called plunger type electromagnetic relay. However, the electromagnetic relay 1 may be of another type. For example,
The magnets 27 and 28 described above may be omitted. In that case, the starting point of the arc generated at the first fixed contact 10 is moved by the self-magnetic field generated from the current flowing through the first fixed contact 10. For example,
In the fifteenth modification, the first arc guide 32 is connected to the contact support portion 31 at a position outward of the first fixed contact 10 in the left-right direction. The second arc guide 33 is connected to the contact support portion 31 at a position inward of the first fixed contact 10 in the left-right direction. Therefore, the first arc guide 32 has both a function of extending an arc and a function of energizing. The second arc guide 33 has a function of energizing.
In the sixteenth modification, the first arc guide 32 is connected to the contact support portion 31 at a position above the fixed contact 10. The second arc guide 33 is connected to the contact support portion 31 at a position below the fixed contact 10. Therefore, the first arc guide 32 has both a function of extending an arc and a function of energizing. The second arc guide 33 has a function of energizing.
In the above embodiment, the magnets 27 and 28 are disposed in the left-right direction with respect to the contacts 10 to 13. However, as in the seventeenth modification shown in
2 Housing
6 First fixed terminal
10 First fixed contact
12 First movable contact
28 magnet
31 Contact support portion
32 First arc guide
33 Second arc guide
44 First step portion
Number | Date | Country | Kind |
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2020-042427 | Mar 2020 | JP | national |
This application is the U.S. National Phase of International Application No. PCT/JP2021/001411, filed on Jan. 18, 2021. This application claims priority to Japanese Patent Application No. 2020-042427, filed Mar. 11, 2020. The contents of those applications are incorporated by reference herein in their entireties.
Filing Document | Filing Date | Country | Kind |
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PCT/JP2021/001411 | 1/18/2021 | WO |