The present invention relates to an electromagnetic relay.
Conventionally, electromagnetic relays that open and close an electric circuit are known. For example, an electromagnetic relay of Japanese Patent No. 6281301 includes a fixed terminal including a fixed contact and a movable contact piece including a movable contact. The movable contact can contact the fixed contact, and the electric circuit is opened and closed when the movable contact contacts the fixed contact or separates from the fixed contact. Further, the electromagnetic relay is provided with a permanent magnet for extending an arc generated when the movable contact separates from the fixed contact (see Japanese Patent No. 6281301). The fixed terminal is formed with a chamfered portion at the end facing the movable contact piece, whereby the arc moves smoothly in a direction away from the fixed contact and the arc is extended.
In Japanese Patent No. 6281301, since the end of the fixed terminal on the side facing the movable contact piece has an edge shape, so the arc stays at this end. Therefore, it is difficult to smoothly move the arc to the surface of the fixed terminal opposite to the movable contact piece. That is, it is difficult to extend the arc smoothly because a smooth movement of the arc is hindered. Similarly, in Japanese Patent No. 6281301, since the end on the side opposite to the fixed terminal of the movable contact piece has an edge shape, it is difficult to smoothly move the arc to the surface opposite to the fixed terminal of the movable contact piece.
An object of the present invention is to smoothly extend the arc in the electromagnetic relay.
An electromagnetic relay according to one aspect of the present invention includes a pair of fixed terminals, a movable contact piece, and a magnet portion. The pair of fixed terminals includes fixed contact. The movable contact piece includes a movable contact disposed facing the fixed contact. The movable contact piece is movable in a first direction in which the movable contact contacts the fixed contact and in a second direction in which the movable contact separates from the fixed contact. The magnet portion generates a magnetic field for extending an arc generated between the fixed contact and the movable contact. At least one of a corner portion in the first direction side of the fixed terminal located in an arc extension direction in which the arc is extended or a corner portion in the second direction side of the movable contact piece located in the arc extension direction has a chamfered shape in a range where the arc passes through.
In this electromagnetic relay, at least one of the corner portion in the first direction side of the fixed terminal located in an arc extension direction or the corner portion in the second direction side of the movable contact piece located in the arc extension direction is chamfered. Therefore, if the corner portion in the first direction side of the fixed terminal located in the arc extension direction is chamfered, the end of the arc can be moved smoothly to the surface in the first direction side of the fixed terminal when the arc is extended by the magnet portion. Also, if the corner portion in the second direction side of the movable contact piece located in the arc extension direction is chamfered, the end of the arc can be moved smoothly to the surface in the second direction side of the movable contact piece when the arc is extended by the magnet portion. As a result, the arc can be smoothly extended.
Preferably, at least one of a corner portion in the second direction side of the fixed terminal located in the arc extension direction or a corner portion in the first direction side of the movable contact piece located in the arc extension direction has a chamfered shape in the range where the arc passes through. In this case, when the arc is extended by the magnet portion, the end portion of the arc can be smoothly moved to the surface in the first direction side of the fixed terminal or the surface in the second direction side of the movable contact piece. As a result, the arc can be further extended smoothly.
Preferably, the arc can be smoothly moved by forming the chamfer shape into a C-chamfered shape or an R-chamfered shape.
Preferably, at least one of a surface of the fixed terminal located in the arc extending direction or a surface of the movable contact piece located in the arc extending direction has an R shape as a whole in the range where the arc passes through. In this case, the arc can be moved more smoothly.
Preferably, at least one of the fixed terminal or the movable contact piece includes a stop portion that stops the movement of the end of the arc. The stop portion is disposed on the first direction side of the fixed terminal or on the second direction side of the movable contact piece. In this case, the stop portion can intentionally stop the movement of the end portion of the arc. Further, since the stop portion is disposed on the opposite side of the contact, there is little possibility that the extension of the arc is greatly hindered.
Preferably, the fixed terminal includes a first fixed terminal including a first fixed contact which is an anode contact, and a second fixed terminal including a second fixed contact. The movable contact piece includes a first movable contact which is a cathode contact disposed facing the first fixed contact, and a second movable contact disposed facing the second fixed contact. The chamfered shapes of the corner portions in the first direction side and second direction side of the movable contact piece located in the arc extension direction with respect to the first movable contact is formed larger than the chamfered shapes of the corner portions in the first direction side and second direction side of the first fixed terminal located in the arc extension direction with respect to the first fixed contact. In this case, by forming a large chamfer shape on the corner of the movable contact piece where the contact on the cathode side, where the arc is less likely to extend than on the anode side, is located, the end portion of the arc can be smoothly moved to the surface in the first direction side of the movable contact piece.
Hereinafter, embodiments of an electromagnetic relay according to one aspect of the present invention will be described with reference to the drawings.
When referring to the drawings, an upper side in
The housing 2 has a substantially quadrangular box shape and is made of an insulating material. The contact device 3, the drive shaft 4, the electromagnetic drive device 5, and the magnet portion 6 are housed inside the housing 2.
The housing 2 includes a housing portion 11. The housing portion 11 is composed of, for example, a substantially rectangular parallelepiped case member arranged in the housing 2. The housing portion 11 is made of an insulating material.
The housing portion 11 includes a housing space 12 for housing the contact device 3. In the present embodiment, the housing space 12 is composed of a substantially rectangular parallelepiped space that is shielded from the outside. The sides of the housing space 12 are surrounded by the first to fourth inner wall surfaces 11a to 11d.
The contact device 3 includes a first fixed terminal 14, a second fixed terminal 15, a movable contact piece 16, and a contact piece holding portion 17. The first fixed terminal 14, the second fixed terminal 15, and the movable contact piece 16 are made of a conductive material.
The first fixed terminal 14 and the second fixed terminal 15 are plate-shaped terminals and extend in the left-right direction. The first fixed terminal 14 and the second fixed terminal 15 are disposed at a distance from each other in the left-right direction. The first fixed terminal 14 and the second fixed terminal 15 are examples of a pair of fixed terminals.
The first fixed terminal 14 includes a first fixed contact 14a and a first external connection portion 14b. The first fixed contact 14a is disposed in the housing space 12. The first external connection portion 14b protrudes leftward from the housing 2 and is exposed to the outside. The second fixed terminal 15 includes a second fixed contact 15a and a second external connection portion 15b. The second fixed contact 15a is disposed in the housing space 12. The second external connection portion 15b protrudes rightward from the housing 2 and is exposed to the outside.
As illustrated in
The movable contact piece 16 is disposed in the housing space 12 at a distance in the left-right direction from the third inner wall surface 11c and the fourth inner wall surface 11d. The movable contact piece 16 is disposed below the first fixed terminal 14 and the second fixed terminal 15. In the present embodiment, a longitudinal direction of the movable contact piece 16 coincides with the left-right direction. Further, a lateral direction of the movable contact piece 16 coincides with the front-back direction.
The movable contact piece 16 includes a first movable contact 16a and a second movable contact 16b. The first movable contact 16a is disposed to face the first fixed contact 14a and can contact the first fixed contact 14a. The second movable contact 16b is disposed at a distance from the first movable contact 16a in the left-right direction. The second movable contact 16b is disposed to face the second fixed contact 15a and can contact the second fixed contact 15a.
The movable contact piece 16 can move in the contact direction Z1 that contacts the first fixed contact 14a and the second fixed contact 15a and the separation direction Z2 that separates from the first fixed contact 14a and the second fixed contact 15a. The contact direction Z1 is an example of the first direction, and the separation direction Z2 is an example of the second direction.
The contact direction Z1 is the direction in which the first movable contact 16a and the second movable contact 16b contact the first fixed contact 14a and the second fixed contact 15a (upward in
As illustrated in
The drive shaft 4 extends along the contact direction Z1 and the separation direction Z2. The drive shaft 4 can move together with the movable contact piece 16 in the contact direction Z1 and the separation direction Z2.
The electromagnetic drive device 5 drives the contact device 3. The electromagnetic drive device 5 moves the movable contact piece 16 together with the drive shaft 4 in the contact direction Z1 and the separation direction Z2 by an electromagnetic force. The electromagnetic drive device 5 is disposed below the housing portion 11 in the housing 2.
The electromagnetic drive device 5 includes a movable iron core 31, a fixed iron core 32, and a yoke 33. Further, the electromagnetic drive device 5 includes a coil, a spool, and a coil spring (not illustrated). Since the electromagnetic drive device 5 has the same configuration as the conventional one, detailed description thereof will be omitted.
The magnet portion 6 generates a magnetic field in the housing to extend an arc generated between the first fixed contact 14a and the first movable contact 16a, and between the second fixed contact 15a and the second movable contact 16b. Specifically, as illustrated in
The first magnet 6a and the second magnet 6b extend in the front-back direction and the up-down direction. The first magnet 6a and the second magnet 6b are fixed to an outer periphery of the housing portion 11 in the present embodiment. The first magnet 6a and the second magnet 6b are disposed around the housing portion 11 so that different poles face each other in the longitudinal direction of the movable contact piece 16. The N pole of the first magnet 6a is disposed facing the housing portion 11. The S pole of the second magnet 6b is disposed facing the housing portion 11. The first magnet 6a and the second magnet 6b disposed in this manner cause a magnetic flux to flow in the housing portion 11 in a direction substantially parallel to the lateral direction of the movable contact piece 16.
Next, the operation of the electromagnetic relay 100 will be described. The operation of the electromagnetic relay 100 is the same as that of the conventional one, it will be briefly described.
Here, as illustrated in
The first fixed terminal 14 includes a first surface 20a, a second surface 20b, a third surface 20c, and a fourth surface 20d. The first surface 20a is a surface of the first fixed terminal 14 on the Z2 side in the separation direction. The second surface 20b is a surface opposite to the first surface 20a, and is a surface on the contact direction Z1 side of the first fixed terminal 14. The first surface 20a and the second surface 20b extend in the front-back direction and the left-right direction. In the present embodiment, the first surface 20a and the second surface 20b have a flat shape. The third surface 20c is a back side surface of the first fixed terminal 14. The fourth surface 20d is a surface opposite to the third surface 20c, and is the front side surface of the first fixed terminal 14. The third surface 20c and the fourth surface 20d extend in the up-down direction and the left-right direction.
The first fixed terminal 14 further includes a first corner portion C1, a second corner portion C2, a third corner portion C3, and a fourth corner portion C4. The first corner portion C1 is located between the second surface 20b and the third surface 20c. The second corner portion C2 is located between the first surface 20a and the third surface 20c. The third corner portion C3 is located between the first surface 20a and the fourth surface 20d. The fourth corner portion C4 is located between the second surface 20b and the fourth surface 20d.
The first corner portion C1 is an example of a corner portion on the contact direction Z1 side of the first fixed terminal 14 located in the arc extension direction. The second corner portion C2 is an example of a corner portion on the separation direction Z2 side of the first fixed terminal 14 located in the arc extension direction. The arc extension direction means the same direction as the Lorentz force F1 acting on the arc.
The first to fourth corner portions C1 to C4 have a chamfered shape. In the present embodiment, each of the first to fourth corner portions C1 to C4 is R-chamfered, and the first surface 20a and the second surface 20b are smoothly connected to the third surface 20c and the fourth surface 20d.
The movable contact piece 16 includes a first surface 30a, a second surface 30b, a third surface 30c, and a fourth surface 30d. The first surface 30a is a surface of the movable contact piece 16 on the contact direction Z1 side, and faces the first surface 20a of the first fixed terminal 14. The second surface 3b is a surface opposite to the first surface 30a, and is a surface of the movable contact piece 16 on the separation direction Z2 side. The first surface 30a and the second surface 30b extend in the front-back direction and the left-right direction. In the present embodiment, the first surface 30a and the second surface 30b have a flat shape. The third surface 30c is a back surface of the movable contact piece 16. The fourth surface 20d is a surface opposite to the third surface 30c, and is a front side surface of the movable contact piece 16. The third surface 30c and the fourth surface 30d extend in the up-down direction and the left-right direction.
The movable contact piece 16 further includes a fifth corner portion C5, a sixth corner portion C6, a seventh corner portion C7, and an eighth corner portion C8. The fifth corner portion C1 is located between the second surface 30b and the third surface 30c. The sixth corner portion C5 is located between the first surface 30a and the third surface 30c. The seventh corner portion C7 is located between the first surface 30a and the fourth surface 30d. The eighth corner portion C8 is located between the second surface 30b and the fourth surface 30d. The fifth corner portion C5 is an example of a corner portion on the separation direction Z2 side of the movable contact piece 16 located in the arc extension direction. The sixth corner portion C6 is an example of a corner portion on the contact direction Z1 side of the movable contact piece 16 located in the arc extension direction.
The fifth to eighth corner portions C5 to C8 have a chamfered shape. In the present embodiment, each of the fifth to eighth corner portions C5 to C8 is R-chamfered, and the first surface 30a and the second surface 30b are smoothly connected to the third surface 30c and the fourth surface 30d.
The distance from the first fixed contact 14a to the second corner portion C2 is about the same as the distance from the first movable contact 16a to the sixth corner portion C6. The distance from the first fixed contact 14a to the third corner portion C3 is about the same as the distance from the first movable contact 16a to the seventh corner portion C7.
As illustrated in
Here, since the first corner portion C1 and the fifth corner portion C5 have a chamfered shape, when the arc is extended by the Lorentz force F1, the ends A1 and A2 of the arc move smoothly from the first surfaces 20a and 30a to the second surfaces 20b and 30b. That is, it is possible to prevent the ends A1 and A2 of the arc from staying at the first corner C1 and the fifth corner C5 and hindering the extension of the arc. As a result, the arc can be extinguished quickly. Further, in the present embodiment, since the second corner portion C2 and the sixth corner portion C6 have a chamfered shape, the ends A1 and A2 of the arc move more smoothly from the first surfaces 20a and 30a to the second surfaces 20b and 30b, and the arc can be extinguished quickly.
The second fixed terminal 15 has a symmetrical shape with the first fixed terminal 14 across the drive shaft 4, and the movable contact piece 16 has a symmetrical shape with the drive shaft 4 across the drive shaft 4. Therefore, even in the arc generated between the second fixed contact 15a and the second movable contact 16b, the same effect as described above can be obtained when the arc is extended by the Lorentz force F2.
Although an embodiment of the electromagnetic relay according to one aspect of the present invention has been described so far, the present invention is not limited to the above embodiment and various modifications can be made without departing from the gist of the invention. For example, the shape or arrangement of the housing 2, the contact device 3, the drive shaft 4, the electromagnetic drive device 5, or the housing portion 11 may be changed.
For example, the first fixed terminal 14 and the second fixed terminal 15 may be bent in a substantially L shape in the housing 2. Further, the first fixed terminal 14 and the second fixed terminal 15 may be disposed below the movable contact piece 16, the electromagnetic drive device 5 may operate to pull the movable contact piece 16 toward the first fixed terminal 14 and the second fixed terminal 15.
In the above embodiment, the magnet portion 6 generates the magnetic field in which the Lorentz forces F1 and F2 act in the direction parallel to the lateral direction of the movable contact piece 16, but the magnet portion 6 generates the magnetic field in which the Lorentz forces F1 and F2 act in the direction parallel to the longitudinal direction of the magnet. In this case, the corners located at both ends of the movable contact piece 16 in the longitudinal direction may have a chamfered shape.
The chamfered shapes of the first to eighth corner portions C1 to C8 may be formed only at the corner portions located in the arc extension direction. Further, as illustrated in
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Number | Date | Country | Kind |
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2018-246970 | Dec 2018 | JP | national |
This application is the U.S. National Phase of International Application No. PCT/JP2019/040810, filed on Oct. 17, 2019. This application claims priority to Japanese Patent Application No. 2018-246970, filed Dec. 28, 2018. The contents of those applications are incorporated by reference herein in their entireties.
Filing Document | Filing Date | Country | Kind |
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PCT/JP2019/040810 | 10/17/2019 | WO | 00 |