Relay

A relay has a case, a first fixed terminal including a first fixed contact, a second fixed terminal including a second fixed contact, a movable touch piece including a first movable contact that is disposed facing the first fixed contact and a second movable contact that is disposed facing the second fixed contact, the movable touch piece being disposed in the case and disposed so as to be movable in a contact direction in which the first movable contact and the second movable contact come into contact with the first fixed contact and the second fixed contact and a separation direction in which the first movable contact and the second movable contact separate from the first fixed contact and the second fixed contact. The first fixed terminal includes a first contact support configured to support the first fixed contact.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Japanese Patent Application No. 2018-068869 filed with the Japan Patent Office on Mar. 30, 2018, the entire contents of which are incorporated herein by reference.

BACKGROUND

Field

The present invention relates to a relay.

Related Art

A relay is provided with a movable touch piece including a movable contact, and a fixed touch piece including a fixed contact. The movable touch piece operates and the movable contact comes in contact with or separates from the fixed contact so that the contacts are opened and closed. Here, an electromagnetic repulsive force due to the Lorentz force is generated in the movable contact and the fixed contact by a current flowing through the movable contact and the fixed contact. This electromagnetic repulsive force acts in a direction to separate the movable contact and the fixed contact. Thus, when an overcurrent is applied, the electromagnetic repulsive force becomes strong, so that contact pressure between the contacts may decrease.

Hence there has hitherto been a relay in which an electromagnetic repulsive force is generated in the direction of pushing the movable contact toward a fixed terminal by providing a portion where currents flow in mutually opposite directions in the movable touch piece and the fixed touch piece. This enables prevention of a decrease in contact pressure between the movable contact and the fixed contact even when an overcurrent is applied.

For example, as illustrated inFIG. 13, an electromagnetic contactor described in Japanese Unexamined Patent Publication No. 2012-243584 includes a movable touch piece101, a first fixed touch piece102, and a second fixed touch piece103. The movable touch piece101includes a first movable contact104and a second movable contact105. The first fixed touch piece102includes a first fixed contact106. The second fixed touch piece103includes a second fixed contact107. When the movable touch piece101operates, the first movable contact104comes into contact with the first fixed contact106and the second movable contact105comes into contact with the second fixed contact107, so that a current I flows through the first fixed touch piece102, the movable touch piece101, and the second fixed touch piece103.

In addition, the first fixed touch piece102has a C-shaped portion108. Hence the first fixed touch piece102and the movable touch piece101have a section in which the directions of the current I are reversed. In this section, electromagnetic repulsive forces in directions repelling each other are generated by the Lorentz force in the first fixed touch piece102and the movable touch piece101. The electromagnetic repulsive force thus acts in a direction in which the first movable contact104is pressed against the first fixed contact106, thereby increasing the contact pressure between the first movable contact104and the first fixed contact106.

Similarly, the second fixed touch piece103has a C-shaped portion109. The electromagnetic repulsive force is thus generated also in the second fixed touch piece103and the movable touch piece101in a direction in which the second movable contact105is pressed against the second fixed contact107, thereby increasing the contact pressure between the second movable contact105and the second fixed contact107.

However, a current has the property of flowing through the shortest path. Therefore, in the electromagnetic contactor described in Japanese Unexamined Patent Publication No. 2012-243584, as illustrated inFIG. 13, the current I does not flow to the end portions110,111of the C-shaped portions108,109, but only partially flows through the C-shaped portions108,109. The electromagnetic repulsive force due to the Lorentz force is thus generated only at both end peripheral portions of the movable touch piece101. Hence the contact pressure between the contacts might decrease.

SUMMARY

One or more embodiments of the present invention prevents a decrease in contact pressure between contacts in a relay.

A relay according to one aspect is provided with a case, a first fixed terminal, a second fixed terminal, and a movable touch piece. The first fixed terminal includes a first fixed contact. The second fixed terminal includes a second fixed contact. The movable touch piece includes a first movable contact and a second movable contact. The first movable contact is disposed facing the first fixed contact. The second movable contact is disposed facing the second fixed contact. The movable touch piece is disposed in the case and disposed so as to be movable in a contact direction in which the first movable contact and the second movable contact come into contact with the first fixed contact and the second fixed contact and in a separation direction in which the first movable contact and the second movable contact separate from the first fixed contact and the second fixed contact.

The first fixed terminal includes a first contact support, a first extension, and a first external connection. The first contact support supports the first fixed contact. The first extension extends in a first direction from the first movable contact to the second movable contact. The first external connection is connected to the first extension and protrudes in the first direction from the case.

The second fixed terminal includes a second contact support, a second extension, and a second external connection. The second contact support supports the second fixed contact. The second extension extends in a second direction from the second movable contact to the first movable contact. The second external connection is connected to the second extension and protrudes in the second direction from the case. At least a part of the first extension overlaps with the movable touch piece as viewed in the movement direction of the movable touch piece.

In the relay according to the present aspect, the first extension extends in the first direction from the first movable contact to the second movable contact, and the first external connection connected to the first extension protrudes in the first direction from the case. Hence in the first fixed terminal, it is possible to ensure a large section in which a current flows in a direction opposite to that of the movable touch piece. This enables an increase in electromagnetic repulsive force acting on the movable touch piece. At least a part of the first extension overlaps with the movable touch piece as viewed in the movement direction of the movable touch piece. It is thus possible to further increase the electromagnetic repulsive force acting on the movable touch piece.

The second extension extends in the second direction from the second movable contact to the first movable contact, and the second external connection connected to the second extension extends in the second direction from the case. Hence in the second fixed terminal, it is possible to ensure a large section in which a current flows in a direction opposite to that of the movable touch piece. Accordingly, the electromagnetic repulsive force acting on the movable touch piece can be further increased by the electromagnetic repulsive force generated between the second extension and the movable touch piece. This can increase the contact pressure between the first movable contact and the first fixed contact and the contact pressure between the second movable contact and the second fixed contact.

Further, the first external connection and the second external connection protrude in mutually opposite directions from the case. This facilitates connecting the first external connection and the second external connection to an external circuit, as compared with a configuration where the first external connection and the second external connection protrude in the same direction.

At least a part of the second extension may overlap with the movable touch piece as viewed in the movement direction of the movable touch piece. In this instance, it is possible to further increase the electromagnetic repulsive force generated between the second extension and the movable touch piece. This can further increase the contact pressure between the first movable contact and the first fixed contact and the contact pressure between the second movable contact and the second fixed contact.

The first extension and the second extension may be arranged symmetrically with respect to a center line of the movable touch piece extending in the movement direction of the movable touch piece. In this instance, the electromagnetic repulsive force by the first extension and the electromagnetic repulsive force by the second extension can equally act on the movable touch piece. Hence it is possible to improve contact stability between the contacts.

The first external connection and the second external connection may be disposed to be flush with each other. In this instance, connecting the first external connection and the second external connection to the external circuit is further facilitated

The first fixed terminal may include an intermediate portion having a shape folded back from the first contact support toward the first extension The case may include a partition disposed between the intermediate portion and the second external connection. The partition may be formed of an insulating material. In this instance, even when the intermediate portion and the second external connection are disposed close to each other, the partition can improve the insulation between the intermediate portion and the second external connection.

The partition may include a division wall and a support. The division wall may be disposed between the intermediate portion and the second external connection. The support may be disposed facing the intermediate portion and support the intermediate portion. In this instance, the partition can serve as a holding structure of the intermediate portion as well as the insulating structure between the intermediate portion and the second external connection.

The first extension and the second extension may be disposed outside the case along the outer surface of the case. In this instance, the first extension and the second extension can be easily attached to the case.

The case may include a protrusion disposed between the first extension and the second extension and protruding from the outer surface. The protrusion may be formed of an insulating material. In this instance, the insulation between the first extension and the second extension can be improved.

The first extension and the second extension may be embedded in the case. In this instance, the first extension and the second extension are protected easily. In addition, the insulation between the first extension and the second extension can be improved.

The first extension and the second extension may be disposed in a housing space in the case. In this instance, the first extension and the second extension are protected easily.

According to the present invention, by increasing the electromagnetic repulsive force in a direction to press the movable contact against the fixed contact, it is possible to prevent a decrease in contact pressure between the contacts.

DETAILED DESCRIPTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In embodiments of the invention, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to one of ordinary skill in the art that the invention may be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid obscuring the invention.FIGS. 1 and 2are perspective views illustrating a relay1according to one or more embodiments of the present invention.FIG. 3is a sectional view of the relay1. As illustrated inFIG. 3, the relay1includes a case2, a contact device3, and a drive device4.

The case2accommodates the contact device3and the drive device4. The case2is formed of a resin having insulation. The case2includes a case body2aand a lid portion2b. The contact device3and the drive device4are disposed in the case body2a. The lid portion2bis separate from the case body2a. The lid portion2bis attached to the case body2a.

The contact device3includes a first fixed terminal5, a second fixed terminal6, a movable touch piece7, and a touch piece holding portion8. The first fixed terminal5, the second fixed terminal6, and the movable touch piece7are formed of a material having conductivity. The first fixed terminal5includes a first fixed contact11. The second fixed terminal6includes a second fixed contact12. The first fixed contact11and the second fixed contact12are spaced apart from each other in a longitudinal direction of the movable touch piece7(a right-left direction inFIG. 3).

The movable touch piece7includes a first movable contact13and a second movable contact14. The first movable contact13is disposed facing the first fixed contact11. The second movable contact14is disposed facing the second fixed contact12. The movable touch piece7is disposed movably in a contact direction (Z1) and a separation direction (Z2).

The contact direction (Z1) is a direction (downward inFIG. 3) in which the first movable contact13and the second movable contact14come into contact with the first fixed contact11and the second fixed contact12. The separation direction (Z2) is a direction (upward inFIG. 3) in which the first movable contact13and the second movable contact14separate from the first fixed contact11and the second fixed contact12. In the following description, a direction from the first movable contact13to the second movable contact14(rightward inFIG. 3) is referred to as a “first direction (X1).” A direction from the second movable contact14to the first movable contact13(leftward inFIG. 3) is referred to as a “second direction (X2).”

The touch piece holding portion8holds the movable touch piece7. The touch piece holding portion8includes a drive shaft15, a holder16, and a contact spring17. The drive shaft15extends in a movement direction (Z1, Z2) of the movable touch piece7. The drive shaft15is disposed movably in the contact direction (Z1) and the separation direction (Z2). The holder16is connected to the movable touch piece7and holds the movable touch piece7. The contact spring17is disposed between the drive shaft15and the holder16.

The first fixed terminal5includes a first contact support21, a first intermediate portion22, a first extension23, and a first external connection24. The first contact support21supports the first fixed contact11. The first contact support21extends in the second direction (X2) from the first fixed contact11in the case2.

The first intermediate portion22connects the first contact support21and the first extension23. At least a part of the first intermediate portion22is disposed so as to be exposed to the outside of the case2. The case2includes a first outer side surface25and a second outer side surface26. The first outer side surface25and the second outer side surface26extend in the movement direction (Z1, Z2) of the movable touch piece7. The first intermediate portion22protrudes in the second direction (X2) from the first outer side surface25of the case2. That is, the first intermediate portion22is exposed to the outside from the first outer side surface25of the case2.

The first intermediate portion22has a shape folded from the first contact support21toward the first extension23. The first intermediate portion22includes a first flat surface27. The first flat surface27is disposed so as to be exposed to the outside of the case2. The first flat surface27is disposed parallel to the first external connection24. The first flat surface27extends in the second direction (X2) from the first outer side surface25of the case2.

The first extension23is disposed apart from the movable touch piece7in the separation direction (Z2). The first extension23has a flat plate shape. The first extension23extends in the first direction (X1). The first extension23extends in the first direction (X1) from the first intermediate portion22to a position beyond the first fixed contact11and the second fixed contact12. The first extension23extends over the entire width of the case2in the first direction (X1).

The first external connection24is connected to the first extension23and protrudes in the first direction (X1) from the second outer side surface26of the case2. The first external connection24is a portion to be connected to an external circuit to which the relay1is attached. The first external connection24is formed integrally with the first extension23. However, the first external connection24may be separate from the first extension23. The first external connection24has a flat plate shape.

In the present embodiment, the first fixed terminal5includes a first fixed touch piece28and a first bus bar29. The first bus bar29and the first fixed touch piece28are separate from each other. The first bus bar29is connected to the first fixed touch piece28. The first fixed touch piece28extends in the second direction (X2) from the first fixed contact11. An end portion of the first fixed touch piece28protrudes outward of the case2. The end portion of the first fixed touch piece28is connected to the first bus bar29outside the case2.

The first fixed touch piece28is connected to the first bus bar29by welding, for example. However, the first fixed touch piece28may be connected to the first bus bar29by another fixing method. For example, the first fixed touch piece28may be connected to the first bus bar29by screws. Alternatively, the first fixed touch piece28may be formed integrally with the first bus bar29.

The first fixed touch piece28includes the first contact support21described above. The first bus bar29includes the first extension23and the first external connection24described above. The first intermediate portion22includes a first attachment portion22aincluded in the first fixed touch piece28and a second attachment portion22bincluded in the first bus bar29. The first attachment portion22ais formed integrally with the first contact support21in the first fixed touch piece28. The second attachment portion22bis formed integrally with the first extension23in the first bus bar29. However, the first attachment portion22amay be separate from the first contact support21. The second attachment portion22bmay be separate from the first extension23. The first attachment portion22aand the second attachment portion22bare disposed so as to be exposed to the outside of the case2.

As illustrated inFIG. 2, the first attachment portion22ahas a shape bent toward the first bus bar29. The second attachment portion22bhas a shape bent from the first attachment portion22atoward the first extension23. The second attachment portion22bis connected to the first attachment portion22a. For example, the second attachment portion22bis connected to the first attachment portion22aby welding. However, the second attachment portion22bmay be connected to the first attachment portion22aby another fixing method. For example, the second attachment portion22bmay be connected to the first attachment portion22aby screws.

The second fixed terminal6has a shape symmetrical with the first fixed terminal5. The second fixed terminal6includes a second contact support31, a second intermediate portion32, a second extension33, and a second external connection34. The second contact support31supports the second fixed contact12. The second contact support31extends in the first direction (X1) from the second fixed contact12in the case2.

The second intermediate portion32connects the second contact support31and the second extension33. At least a part of the second intermediate portion32is disposed so as to be exposed to the outside of the case2. The second intermediate portion32protrudes in the first direction (X1) from the second outer side surface26of the case2. That is, the second intermediate portion32is exposed to the outside from the second outer side surface26of the case2.

The second intermediate portion32has a shape folded back from the second contact support31toward the second extension33. The second intermediate portion32includes a second flat surface37. The second flat surface37is disposed so as to be exposed to the outside of the case2. The second flat surface37is disposed parallel to the second external connection34. The second flat surface37extends in the first direction (X1) from the second outer side surface26of the case2.

The second extension33is disposed apart from the movable touch piece7in the separation direction (Z2). The second extension33has a flat plate shape. The second extension33extends in the second direction (X2). The second extension33extends in a second direction (X2) from the second intermediate portion32to a position beyond the second fixed contact12and the first fixed contact11. The second extension33extends over the entire width of the case2in the second direction (X2).

The second external connection34is connected to the second extension33and protrudes in the second direction (X2) from the first outer side surface25of the case2. The second external connection34is a portion connected to the external circuit. The second external connection34is formed integrally with the second extension33. However, the second external connection34may be separate from the second extension33. The second external connection34has a flat plate shape.

In the present embodiment, the second fixed terminal6includes a second fixed touch piece38and a second bus bar39. The second bus bar39is separate from the second fixed touch piece38. The second bus bar39is connected to the second fixed touch piece38. The second fixed touch piece38extends in the first direction (X1) from the second fixed contact12. An end portion of the second fixed touch piece38protrudes outward of the case2. The end portion of the second fixed touch piece38is connected to the second bus bar39outside the case2.

The second fixed touch piece38is connected to the second bus bar39by welding, for example. However, the second fixed touch piece38may be connected to the second bus bar39by another fixing method. For example, the second fixed touch piece38may be connected to the second bus bar39by screws. Alternatively, the second fixed touch piece38may be formed integrally with the second bus bar39.

The second fixed touch piece38includes the second contact support31described above. The second bus bar39includes the second extension33and the second external connection34. The second intermediate portion32includes a first attachment portion32aincluded in the second fixed touch piece38and a second attachment portion32bincluded in the second bus bar39. The first attachment portion32ais formed integrally with the second contact support31in the second fixed touch piece38. The second attachment portion32bis formed integrally with the second extension33in the second bus bar39. However, the first attachment portion32amay be separate from the second contact support31. The second attachment portion32bmay be separate from the second extension33. The first attachment portion32aand the second attachment portion32bare disposed so as to be exposed to the outside of the case2.

The first attachment portion32ahas a shape bent toward the second bus bar39. The first attachment portion32ais connected to the second attachment portion32b. The second attachment portion32bhas a shape bent from the first attachment portion32atoward the second extension33. For example, the first attachment portion32ais connected to the second attachment portion32bby welding. However, the first attachment portion32amay be connected to the second attachment portion32bby another fixing method. For example, the first attachment portion32amay be connected to the second attachment portion32bby screws.

FIG. 6is a sectional view taken along a line VI-VI inFIG. 5. As illustrated inFIG. 6, the first extension23and the second extension33are embedded in the case2. Specifically, the first extension23and the second extension33are embedded in the lid portion2b. The first extension23and the second extension33are arranged symmetrically with respect to a center line C1of the movable touch piece7extending in the movement direction (Z1, Z2) of the movable touch piece7.

As illustrated inFIG. 4, the first extension23and the second extension33are arranged symmetrically with respect to a center line C2of the movable touch piece7extending in the longitudinal direction of the movable touch piece7. A part of the first extension23overlaps with the movable touch piece7as viewed in the movement direction (Z1, Z2) of the movable touch piece7. A part of the second extension33overlaps with the movable touch piece7as viewed in the movement direction (Z1, Z2) of the movable touch piece7. As viewed in the movement direction (Z1, Z2) of the movable touch piece7, the range where the first extension23overlaps with the movable touch piece7has the same size as the range where the second extension33overlaps with the movable touch piece7.

The first extension23and the second extension33are disposed at the same height with the movement direction (Z1, Z2) of the movable touch piece7as a height direction. The first extension23and the second extension33are disposed to be flush with each other. The first external connection24and the second external connection34are disposed at the same height with the movement direction (Z1, Z2) of the movable touch piece7as the height direction. The first external connection24and the second external connection34are disposed to be flush with each other. The first flat surface27and the second flat surface37are disposed at the same height with the movement direction (Z1, Z2) of the movable touch piece7as the height direction. The first flat surface27and the second flat surface37are disposed to be flush with each other.

Next, the drive device4will be described. The drive device4generates a driving force for operating the movable touch piece7. The drive device4operates the movable touch piece7by an electromagnetic force. The drive device4includes a coil41, a spool42, a core43, a return spring44, and a yoke45.

The coil41is wound around the spool42. The coil41and the spool42are disposed coaxially with the drive shaft15. The coil41is connected to the coil terminal46illustrated inFIG. 6. As illustrated inFIG. 6, the leading end of the coil terminal46is disposed in a connector47.

The spool42includes a hole42apenetrating in an axial direction of the spool42. The iron core43and the return spring44are inserted into a hole42aof the spool42. The iron core43includes a fixed iron core43aand a movable iron core43b. The fixed iron core43ais fixed to a second yoke45b, the spool42, or the case2. The yoke45is connected to the iron core43.

The yoke45includes a first yoke45aand a second yoke45b. The first yoke45ais disposed between the contact device3and the spool42. The second yoke45bis connected to the first yoke45a. The second yoke45bhas a U-shape. The second yoke45bis disposed on each side of the coil41and on the side opposite to the first yoke45awith respect to the coil41. The first yoke45ais connected to one end of the iron core43. The second yoke45bis connected to the other end of the iron core43.

The iron core43includes a fixed iron core43aand a movable iron core43b. The fixed iron core43ais fixed to the second yoke45b. The movable iron core43bis separate from the fixed iron core43a. The movable iron core43bis disposed movably in the contact direction (Z1) and the separation direction (Z2). The movable iron core43bis connected to the drive shaft15. The return spring44is disposed between the movable iron core43band the fixed iron core43a. The return spring44urges the movable iron core43bin the separation direction (Z2).

Next, the operation of the relay1will be described. When no voltage is applied to the coil41, the drive shaft15is pressed, together with the movable iron core43b, in the separation direction (Z2) by an elastic force of the return spring44. Therefore, the movable touch piece7is also pressed in the separation direction (Z2), and the first movable contact13and the second movable contact14are in an open state, being separated from the first fixed contact11and the second fixed contact12.

When a voltage is applied to the coil41and excited, the movable iron core43bmoves in the contact direction (Z1) against the elastic force of the return spring44. Thus, by movement of the drive shaft15and the movable touch piece7in the contact direction (Z1), the first movable contact13and the second movable contact14are brought into a closed state, being in contact with the first fixed contact11and the second fixed contact12. In this closed state, a current flows from the first fixed terminal5to the second fixed terminal6through the movable touch piece7.

FIG. 7is a diagram illustrating the flow of the current I in the closed state. As illustrated inFIG. 7, the current I flows from the first external connection24to the movable touch piece7through the first extension23, the first intermediate portion22, the first contact support21, the first fixed contact11, and the first movable contact13. The current I passes from the movable touch piece7through the second movable contact14, the second fixed contact12, the second contact support31, the second intermediate portion32, and the second extension33, and the second external connection34.

In the relay1according to the present embodiment, the first extension23extends in a first direction (X1) from the first movable contact13to the second movable contact14, and the first external connection24connected to the first extension23protrudes in the first direction (X1) from the case2. The current I flows in the first extension23in a direction opposite to that of the movable touch piece7. Hence in the first fixed terminal5, it is possible to ensure a large section in which the current I flows in the opposite direction to the movable touch piece7. This enables an increase in electromagnetic repulsive force acting on the movable touch piece7.

Further, the second extension33extends in the second direction (X2) from the second movable contact14to the first movable contact13, and the second external connection34connected to the second extension33protrudes in the second direction (X2) from the case2. A current I flows in the second extension33in a direction opposite to that of the movable touch piece7. Therefore, in the second fixed terminal6, it is possible to ensure a large section in which the current I flows in the opposite direction to the movable touch piece7. Thereby, the electromagnetic repulsive force acting on the movable touch piece7can be further increased.

As described above, in the relay according to the present embodiment, a current flows in the first extension23and the second extension33in a direction opposite to that of the movable touch piece7, thereby acting on the movable touch piece7The electromagnetic repulsive force can be increased. This can increase the contact pressure between the first movable contact13and the first fixed contact11and the contact pressure between the second movable contact14and the second fixed contact12.

Since the electromagnetic repulsive force can be sufficiently increased by the first extension23and the second extension33, even when the space between the first bus bar29and the second bus bar39and the movable touch piece is widened, sufficient contact pressure between the contacts can be ensured. Therefore, it is easy to ensure a space for the arc to extend when the load is cut off.

In addition, the first external connection24protrudes in the first direction (X1) from the case2, and the second external connection34protrudes in the second direction (X2) from the case2. Hence the first external connection24and the second external connection34protrude in mutually opposite directions from the case2. This facilitates connecting the first external connection24and the second external connection34to the external circuit, as compared with a configuration where the first external connection24and the second external connection34protrude in the same direction.

At least a part of the first extension23overlaps with the movable touch piece7as viewed in the movement direction (Z1, Z2) of the movable touch piece7. At least a part of the second extension33overlaps with the movable touch piece7as viewed in the movement direction (Z1, Z2) of the movable touch piece7. Therefore, the electromagnetic repulsive force acting on the movable touch piece7can be further increased. This can further increase the contact pressure between the first movable contact13and the first fixed contact11and the contact pressure between the second movable contact14and the second fixed contact12.

The first extension23and the second extension33are arranged symmetrically with respect to a center line C1of the movable touch piece7extending in the movement direction (Z1, Z2) of the movable touch piece7. Therefore, the electromagnetic repulsive force of the first extension23and the electromagnetic repulsive force of the second extension33can equally act on the movable touch piece7. Hence it is possible to improve contact stability between the contacts.

The first external connection24and the second external connection34are disposed to be flush with each other. This further facilitates connecting the first external connection24and the second external connection34to the external circuit. For example, the first external connection24and the second external connection34can be easily connected to a common substrate of external circuits.

The first extension23and the second extension33are embedded in the case2. This facilitates protecting the first extension23and the second extension33. A part of the case2formed of an insulating resin is disposed between the first extension23and the second extension33. Therefore, even when the first extension23and the second extension33are disposed close to each other, the insulation between the first extension23and the second extension33can be improved.

Although embodiments of the present invention are described the above, the present invention is not limited to the above embodiments, and various changes can be made in the scope not deviating from the gist of the present invention. For example, the configuration of the drive device4may be changed. The shape or placement of the coil41, the spool42, the iron core43, the return spring44, or the yoke45may be changed.

The shape or placement of the first fixed terminal5, the second fixed terminal6, and the movable touch piece7may be changed. For example, the placement of the first fixed terminal5and the second fixed terminal6is not limited to that of the embodiment described above, and may be interchanged.

In the above embodiment, by the drive device4drawing the drive shaft15toward the coil41side, the movable touch piece7moves in the contact direction (Z1). By the drive device4pushing the drive shaft15from the coil41side, the movable touch piece7moves in the separation direction (Z2). However, by the drive device4drawing the drive shaft15toward the coil41side, the movable touch piece7may move in the separation direction (Z2). By the drive device4pushing the drive shaft15from the coil41side, the movable touch piece7may move in the contact direction (Z1).

In the above embodiment, the first extension23and the second extension33are arranged symmetrically with respect to the center line C1of the movable touch piece7. However, the placement of the first extension23and the second extension33may be changed.

FIG. 8is a sectional view of the relay1according to a first modified example. As illustrated inFIG. 8, the first extension23and the second extension33may be arranged asymmetrically with respect to the center line C1of the movable touch piece7. As viewed in the movement direction (Z1, Z2) of the movable touch piece7, of the first extension23and the second extension33, only the first extension23overlaps with the movable touch piece7, and the second extension33may be disposed at a position not overlapping with the movable touch piece7. As viewed in the movement direction (Z1, Z2) of the movable touch piece7, the whole of the first extension23may overlap with the movable touch piece7.

The shape or placement of the case2may be changed.FIG. 9is a side view of the relay1according to a second modified example. As illustrated inFIG. 9, the case2may include a partition48. The partition48is disposed between the first intermediate portion22and the second external connection34. The partition48is formed of an insulating material. Specifically, the partition48includes a division wall48aand a support48b. The division wall48ais disposed between the first intermediate portion22and the second external connection34. The support48bis disposed facing the first intermediate portion22and supports the first intermediate portion22.

In this instance, even when the first intermediate portion22and the second external connection34are disposed close to each other, the partition48improves the insulation between the first intermediate portion22and the second external connection34. Further, the partition48can also serve as the holding structure of the first intermediate portion22as well as the insulating structure between the first intermediate portion22and the second external connection34.

In the partition48, only the division wall48amay be provided, and the support48bmay be omitted. Like the partition48, a partition may be provided between the second intermediate portion32and the first external connection24.

In the above embodiment, the first extension23and the second extension33are embedded in the lid portion2bof the case2. However, the first extension23and the second extension33may be embedded in other portions of the case2. Alternatively, the first extension23and the second extension33may be disposed outside the case2.

FIG. 10Ais a plan view of the relay1according to a third modified example.FIG. 10Bis a front view of the relay1according to the third modified example.FIG. 11is a side view of the relay1according to the third modified example. As illustrated inFIGS. 10A, 10B, and 11, the first extension23and the second extension33may be disposed outside the case2along the outer surface of the case2.

Further, the case2may include the protrusion49. The protrusion49is formed of an insulating material. The protrusion49is disposed between the first extension23and the second extension33and protrudes from the outer surface. The protrusion49extends along the first extension23and the second extension33. Even when the first extension23and the second extension33are disposed close to each other by the protrusion49, it is possible to improve the insulation between the first extension23and the second extension33it can.

FIG. 12is a sectional view of the relay1according to a fourth modified example. As illustrated inFIG. 12, the first extension23and the second extension33may be disposed in the accommodation space inside the case2. A portion of the first fixed terminal5other than the first external connection24and the first intermediate portion22may be disposed in the accommodation space inside the case2. The first external connection24and the first intermediate portion22may be disposed outside the case2. A portion of the second fixed terminal6other than the second external connection34and the second intermediate portion32may be disposed in the accommodation space inside the case2. The second external connection34and the second intermediate portion32may be disposed outside the case2.

Alternatively, only the first external connection24of the first fixed terminal5may be disposed outside the case2, and a portion other than the first external connection24may be disposed in the accommodation space in the case2. Only the second external connection34of the second fixed terminal6may be disposed outside the case2and a portion other than the second external connection34may be disposed in the accommodation space in the case2.

According to one or more embodiments of the present invention, by increasing the electromagnetic repulsive force in a direction to press the movable contact against the fixed contact, it is possible to prevent a decrease in contact pressure between the contacts.