Patent Application
20240145195
The claimed invention relates to electromagnetic relays.
Conventionally, an electromagnetic relay for opening and closing an electric circuit is known. The electromagnetic relay has a fixed terminal configured to be connected to an external terminal. For example, the fixed terminal disclosed in Japanese Patent Application Publication No. 2014-049208 includes a cylindrical terminal and a plate terminal fixed to the cylindrical terminal. The plate terminal is connected to the external terminal by screw fastening.
In the electromagnetic relay of Japanese Patent Application Publication No. 2014-049208, when an external force is applied to the external terminal by screws or an accidental external force is applied to the external terminal, the plate terminal may be deformed and the function of the electromagnetic relay may be impaired.
The claimed invention provides an electromagnetic relay in which the deformation of fixed terminal due to external force is decreased.
An electromagnetic relay according to one aspect of the claimed invention includes a case, a fixed terminal, and a female screw member. The fixed terminal has a plate-like shape. The fixed terminal includes an external connecting portion. The external connecting portion has a screw insertion hole, is exposed to the outside from the case, and configured to be screwed to an external terminal. The female screw member is a member for screwing the external connecting portion to the external terminal. The female screw member is prevented from rotation by the case. The case includes a held portion to be held between the external connecting portion of the fixed terminal and the female screw member in a direction of penetration of the screw insertion hole, the direction of penetration including a first direction from the female screw member toward the external connecting portion and a second direction from the external connecting portion toward the female screw member.
In this electromagnetic relay, the held portion of the case is held between the external connecting portion of the fixed terminal and the female screw member in the direction of penetration of the screw insertion hole. Thus, the external terminal, the fixed terminal, and the case are fastened together when the external terminal is screwed to the external connecting portion of the fixed terminal. With the configuration, the held portion increases the strength of the fixed terminal, and thereby deformation of the fixed terminal due to external force can be decreased. Also, the female screw member becomes less likely to come off from the case.
The female screw member may include a flange portion having an outer diameter larger than an outer diameter of an end surface of the female screw member in the first direction. The held portion of the case may be sandwiched between the external connecting portion of the fixed terminal and the flange portion of the female screw member in the direction of penetration of the screw insertion hole. In this case, the held portion is increased in size, and thereby the strength of the fixed terminal is further improved. Also, when an external terminal is screwed to the external connecting portion, damage to the case due to overtightening of the screw can be reduced.
The female screw member may have an end surface exposed to the outside from the case in the second direction. In this case, for example, the heat generated at the fixed terminal when energized can be released to the outside through the female screw member.
The case may include a case body and an outer support portion located outside the case body to be in contact with the external connecting portion. The female screw member may be positioned on the outer support portion. In this case, the external connecting portion can be supported by the outer support portion.
The external connecting portion of the fixed terminal may include a first surface contacting the held portion, a second surface opposite the first surface, and a side surface between the first surface and the second surface. The sides may be, at least partially, held by the outer support of the case. In this case, the fixed terminal can be held firmly.
The outer support portion of the case may include a retaining groove to retain the female screw member therein. The retaining groove may have an opening to insert to the female screw. The opening may be opened in a direction intersecting the direction of penetration of the screw insertion hole. In this case, the female screw member can be held by the case by a means different from insert molding.
The case may be comprised of resin. In this case, the female screw member can be fixed to the case by insert molding.
An embodiment of an electromagnetic relay 100 according to one aspect of the claimed invention will be described below with reference to the drawings. When referring to the drawings in the description below, the X1 direction is the leftward direction, the X2 direction is the rightward direction, the Y1 direction is the forward direction, the Y2 direction is the rearward direction, the Z1 direction is the upward direction, and the Z2 direction is the downward direction. These directions are defined for convenience of description, and do not limit the directions in which the electromagnetic relay 100 is arranged. In the present embodiment, the Z1 direction is an example of a first direction, and the Z2 direction is an example of a Second direction.
As shown in
The case 2 is a generally rectangular box in shape and is comprised of insulating material such as resin. In the present embodiment, the case 2 is comprised of resin. The case 2 includes a case body 21, a lid 22, inner support portions 23, 24, and outer support portions 25, 26.
The case body 21 has an opening at the front. The case body 21 includes a left wall 21a, a right wall 21b, an upper wall 21c, a lower wall 21d, and a rear wall (not shown). The left wall 21a and right wall 21b extend in the front-rear direction and the up-down direction. The left wall 21a faces the right wall 21b in the left-right direction. The upper wall 21c and the lower wall 21d extend in the front-rear direction and the left-right direction. The upper wall 21c faces the lower wall 21d in the up-down direction. The rear wall extends in the left-right direction and the up-down direction. The rear wall is connected to the left wall 21a, the right wall 21b, the upper wall 21c and the lower wall 21d. The lid 22 is attached to the case body 21 so as to close the opening of the case body 21.
The inner support portion 23 protrudes rightward from an inner surface of the left wall 21a. The inner support portion 24 protrudes leftward from an inner surface of the right wall 21b. The inner support portions 23, 24 each have a flat upper surface. That is, the upper surfaces of the inner support portions 23, 24 include a plane perpendicular to the up-down direction.
The outer support portion 25 is disposed outside the case body 21. The outer support portion 25 protrudes leftward from an outer surface of the left wall 21a. The outer support portion 25 is disposed below the inner support portion 23. The outer support portion 26 protrudes rightward from an outer surface of the right wall 21b. The outer support portion 26 is disposed below the inner support portion 24. The outer support portions 25 and 26 each have a flat upper surface. That is, the upper surfaces of the outer support portions and 26 include a plane perpendicular to the up-down direction.
The contact device 3 includes fixed terminals 6 and 7 and a movable contact piece 8. The fixed terminals 6 and 7 may be plate terminals and are comprised of conductive material. The fixed terminals 6 and 7 extend in the left-right direction and have a bent shape. The fixed terminals 6 and 7 extend across the interior and exterior of the case 2. The fixed terminals 6 and 7 are arranged apart from each other in the left-right direction. The fixed terminals 6 and 7 are held by the case 2.
The fixed terminal 6 includes a fixed contact 6a, a contact support portion 6b, an extension portion 6c, a bent portion 6d, an external connecting portion 6e, and a screw insertion hole 6f. The fixed contact 6a is disposed inside the case 2. The fixed contact 6a is disposed facing the movable contact piece 8 in the up-down direction. The fixed contact 6a is disposed on the lower surface of the contact support portion 6b. The contact support portion 6b supports the fixed contact 6a.
The extension portion 6c extends leftward from the contact support portion 6b. The extension portion 6c is supported on the upper surface of the inner support portion 23. The bent portion 6d is arranged outside the case 2. The bent portion 6d is connected to the extension portion 6c. The bent portion 6d extends in the up-down direction. The bent portion 6d extends in a bending form in the Z2 direction from the left end of the extension portion 6c.
The external connecting portion 6e is exposed to the outside from the case 2. The external connecting portion 6e is connected to the bent portion 6d. The external connecting portion 6e extends leftwards from the bent portion 6d. The external connecting portion 6e is to be in contact with the upper surface of the outer support portion 25. The external connecting portion 6e is to be connected to an external terminal 30 (see
The screw insertion hole 6f is located in the external connecting portion 6e. The screw insertion hole 6f penetrates through the external connecting portion 6e in the up-down direction. In the present embodiment, the direction of penetration of the screw insertion hole 6f coincides with the up-down direction. Thus, the direction of penetration of the screw insertion hole 6f encompasses the Z1 direction from the female screw member 31 to the external connecting portion 6e and the Z2 direction from the external connecting portion 6e to the female screw member 31, which will be described later.
The fixed terminal 7 is bilaterally symmetric with the first fixed terminal 6, so detailed description thereof will be omitted. The fixed terminal 7 includes a fixed contact 7a, a contact support portion 7b, an extending portion 7c, a bent portion 7d, an external connecting portion 7e, and a screw insertion hole 7f. The fixed contact 7a is arranged to face the movable contact piece 8 in the up-down direction at a position spaced from the fixed contact 6a in the left-right direction. The contact support portion 7b supports the fixed contact 7a. The extending portion 7c is supported on the upper surface of the inner support portion 24. The bent portion 7d extends in the up-down direction outside the case 2. The external connecting portion 7e extends in the left-right direction and is supported on the upper surface of the outer support portion 26.
The external connecting portion 7e is to be connected to an external terminal (not shown) such as a busbar by screwing. The screw insertion hole 7f penetrates through the external connecting portion 7e in the up-down direction.
The movable contact piece 8 is a plate terminal elongated in one direction and comprised of conductive material. The movable contact piece 8 is located inside the case 2. The movable contact piece 8 extends in the left-right direction inside the case 2.
The movable contact piece 8 includes movable contacts 8a, 8b. The movable contact 8a is disposed to face the fixed contact 6a. The movable contact 8b is disposed to face the fixed contact 7a.
The movable contact piece 8 is movable in the up-down direction. That is, the movable contact piece 8 is movable in the Z1 direction and the Z2 direction. In the present embodiment, the Z1 direction coincides with the direction from the movable contact 8a toward the fixed contact 6a. The Z2 direction coincides with the direction from the fixed contact 6a toward the movable contact 8a.
The driving device 4 is positioned inside the case 2. The driving device 4 is configured to move the movable contact piece 8 in the Z1 direction and the Z2 direction. The driving device 4 includes a movable mechanism 11, a coil 12, a movable iron core 13, a fixed iron core 14, a yoke 15, and a return spring 16.
The movable mechanism 11 is connected to the movable contact piece 8. As shown in
When a voltage is applied to the coil 12 to excite it, the coil 12 generates an electromagnetic force that causes the movable iron core 13 to move in the Z1 direction. The movable iron core 13 is fixed to the drive shaft 11b so as to be movable integrally therewith. The fixed iron core 14 is disposed above the movable iron core 13 so as to face the movable iron core 13. The yoke 15 is arranged to surround the coil 12. The yoke 15 is connected to the fixed iron core 14. The return spring 16 urges the movable iron core 13 in the Z2 direction.
The electromagnetic relay 100 further includes a female screw member 31. The female screw member 31 is supported by the case 2. The female screw member 31 is a member for screwing the external connecting portion 6e to the external terminal 30. The female screw member 31 in the present embodiment is, for example, a hexagonal nut. The female screw member 31 is prevented from rotating by the case 2. In the present embodiment, the female screw member 31 is fixed to the case 2 by insert molding.
The female screw member 31 is in contact with the external connecting portion 6e via the outer support portion 25 in the direction of penetration of the screw insertion hole 6f. Specifically, the case 2 further includes a held portion 42. The held portion 42 is held between the external connecting portion 6e and the female screw member 31 in the direction of penetration of the screw insertion hole 6f. The held portion 42 extends in the up-down direction. The held portion 42 is constituted by part of the outer support portion 25. The held portion 42 overlaps the external connecting portion 6e and the female screw member 31 in the direction of penetration of the screw insertion hole 6f. The held portion 42 is pressed in the Z1 and Z2 directions when the external connecting portion 6e is screwed to the external terminal 30. The held portion 42 may be pressed in the Z2 direction by the external connecting portion 6e when the external connecting portion 6e is not screwed to the external terminal 30.
The female screw member 31 includes end surfaces 31a and 31b. The end surface 31a is the end surface in the Z1 direction and is in contact with the held portion 42. The end surface 31b is an end surface in the Z2 direction and is exposed to the outside from the external connecting portion 6e of the case 2. The end surface 31b is arranged flush with the lower surface of the external connecting portion 6e.
The external connecting portion 6e includes a first surface 61, a second surface 62 opposite the first surface 61, and a side surface 63 between the first surface 61 and the second surface 62. The first surface 61 is the lower surface of the external connecting portion 6e and is in contact with the outer support portion 25 and the held portion 42. The second surface 62 is the upper surface of the external connecting portion 6e and is in contact with the external terminal 30.
In the electromagnetic relay 100 configured as described above, the held portion 42 of the case 2 is held between the external connecting portion 6e of the fixed terminal 6 and the female screw member 31 in the direction of penetration of the screw insertion hole 6f. Thus, when the external terminal is screwed to the external connecting portion 6e of the fixed terminal 6, the external terminal 30, the fixed terminal 6 and the case 2 are fastened together. With the configuration, the held portion 42 increases the strength of the fixed terminal 6, thereby decreasing the deformation of the fixed terminal 6 due to external force. In addition, the female screw member 31 becomes less likely to come off from the case 2.
Note that the electromagnetic relay 100 further includes a female screw member 32, as shown in
An embodiment of the electromagnetic relay according to one aspect of the claimed invention has been described above, but the claimed invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2021-035747 | Mar 2021 | JP | national |
This application is the U.S. National Phase of International Application No. PCT/JP2022/001497, filed on Jan. 18, 2022. This application claims priority to Japanese Patent Application No. 2021-035747, filed Mar. 5, 2021. The contents of those two applications are incorporated by reference herein in their entireties.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2022/001497 | 1/18/2022 | WO |
