The present invention relates to an electromagnetic relay.
An electromagnetic relay has been conventionally known that opens and closes an electrical circuit. For example, German Utility Model No. 202013006784 discloses an electromagnetic relay that includes a fixed terminal having a fixed contact, a movable contact piece having a movable contact, and a movable member for transmitting the rotation of a movable iron core to the movable contact piece. The movable contact piece slides with respect to the movable member in response to the movement of the movable member.
In the electromagnetic relay of German Utility Model No. 202013006784, the movable contact piece and the movable member slide on each other, and the abrasion powder generated by the sliding is likely to adhere to the fixed contact or the movable contact. Any abrasion powder adhering to the fixed contact or the movable contact increases the contact resistance between the contacts, leading to degradation in performance of electrical conduction.
An object of the present invention is to decrease adhering of abrasion power to the contacts in an electromagnetic relay.
An electromagnetic relay according to one aspect of the present invention includes a base, a first fixed terminal, a second fixed terminal, a movable contact piece, a movable member, and a return spring. The first fixed terminal includes a first fixed contact and is supported by the base. The second fixed terminal includes a second fixed contact and is supported by the base at a position separated from the first fixed terminal. The movable contact piece includes a pair of movable contacts configured to contact the first fixed contact and the second fixed contact. The movable contact piece is fixed to the movable member, and the movable member is movable in a contact direction in which the first fixed contact and the second fixed contact come into contact with the pair of movable contacts and in a separation direction in which the first fixed contact and the second fixed contact are separated from the pair of movable contacts. The return spring is disposed between the base and the movable member and urges the movable member in the separation direction. The base includes a guide portion to guide the movement of the movable member. The movable member includes a sliding portion slidable with respect to the guide portion. The return spring is disposed inside the guide portion. The guide portion is disposed in the contact direction with respect to the first fixed contact and the second fixed contact.
In the electromagnetic relay, the movable contact piece is fixed to the movable member. In other words, the movable contact piece and the movable member do not slide on each other, and thereby no abrasion power is generated by sliding between the movable contact piece and the movable member. As such, it is possible to decrease the adhesion of the abrasion powder to the first fixed contact, the second fixed contact, or the pair of movable contacts. Further, since the guide portion is disposed closer to the contact direction side than the first fixed contact and the second fixed contact, the guide portion is disposed at a position apart from the first fixed contact, the second fixed contact, and the pair of movable contacts. As a result, it is possible to decrease the adhesion of the abrasion powder, which is generated by the sliding of the movable member along the guide portion, to the first fixed contact, the second fixed contact, or the pair of movable contacts. Furthermore, since the return spring is disposed inside the guide portion, it is possible to decrease the adhesion of the abrasion powder generated between the return spring and the base to the first fixed contact, the second fixed contact, or the pair of movable contacts.
The sliding portion may have a first end on the contact direction side. The guide portion may have a second end on the separation direction side. The first end may be positioned in the contact direction with respect to the second end. In this case, the return spring is not exposed in the space where the first fixed contact, the second fixed contact, and the pair of movable contacts are disposed. Thus, it is possible to further decrease the adhesion of the abrasion powder generated by the contact between the movable member and the return spring and the abrasion powder generated by the sliding of the sliding portion along the guide portion to the first fixed contact, the second fixed contact, or the pair of movable contacts.
The base may include a recess recessed in the separation direction. The sliding portion and the return spring may be disposed inside the recess. The guide portion may be constituted by part of the recess. In this case, the movable member can be guided to move by a simple configuration.
The movable member may include a first spring housing portion opposite the recess to house the return spring partially. The return spring may be surrounded by the recess and the first spring housing portion. In this case, it is possible to further decrease the adhesion of the abrasion powder generated by the contact between the movable member and the return spring and the abrasion powder generated by the sliding of the sliding portion along the guide portion to the first fixed contact, the second fixed contact, or the pair of movable contacts.
One of the base or the movable member may include a positioning portion configured to position the return spring. In this case, positioning of the return spring is facilitated.
The sliding portion may have a first end on the contact direction side. The guide portion may have a second end on the separation direction side. At least one of the first end or the second end may have a C-chamfered shape or an R-chamfered shape. In this case, it is possible to decrease the abrasion powder generated by sliding of the sliding portion along the guide portion. Also, the assembly is facilitated.
The electromagnetic relay may further include a contact spring configured to urge the movable member in the contact direction. The movable member may include a second spring housing portion configured to house the contact spring partially. In this case, it is possible to further decrease the adhesion of the abrasion powder generated by contact between the movable member and the contact spring to the first fixed contact, the second fixed contact, or the pair of movable contacts.
The electromagnetic relay may further include a contact spring configured to urge the movable member in the contact direction, and a first spring bearing member disposed between the contact spring and the movable member. The contact spring may urge the movable member in the contact direction via the first spring bearing member. In this case, for example, the first spring bearing member may be formed of a material such as stainless steel, so that less abrasion powder is generated compared to the case where the contact spring is brought into direct contact with the movable member.
The electromagnetic relay may further include a second spring bearing member disposed between the return spring and the movable member. The return spring may urge the movable member in the separation direction via the second spring bearing member. In this case, for example, the second spring bearing member may be formed of a material such as stainless steel, so that less abrasion powder is generated compared to the case where the contact spring is brought into direct contact with the movable member.
The movable contact piece may be fixed to the movable member by insert molding. In this case, the movable contact piece can be easily fixed to the movable member.
The movable member may be composed of at least two components including a first component and a second component. The movable contact piece may be fixed to the movable member in a state in which the movable contact piece is sandwiched between the first component and the second component. In this case as well, the movable contact piece can be easily fixed to the movable member.
The electromagnetic relay may further include an elastic member disposed between the first component and the movable contact piece or between the second component and the movable contact piece. The movable contact piece may be fixed to the movable member via the elastic member. In this case, the movable contact piece can be firmly fixed to the movable member.
The first component and the second component may be formed of different materials. In this case, the degree of freedom in design increases.
The first component may be formed of an insulating material. The second component may be formed of a metal material and may be disposed in the contact direction with respect to the first component. In this case, heat generation of a contact device can be reduced by the second component while ensuring the insulation by the first component.
Hereinafter, an electromagnetic relay of an embodiment according to an aspect of the present invention will be described with reference to the drawings. When referring to the drawings, the up-down direction in
As shown in
The first fixed terminal 6 includes a first contact support portion 6a, a first fixed contact 6b, a supported portion 6c, and an external connection portion 6d. The first contact support portion 6a extends in the X direction and the Y axis direction. The first fixed contact 6b is disposed on the first contact support portion 6a. The first fixed contact 6b protrudes in the Z2 direction from the first contact support portion 6a. In the present embodiment, the first fixed contact 6b is a separate body from the first fixed terminal 6, but may be integrated with the first fixed terminal 6. The supported portion 6c extends in the X direction and the Z direction. The supported portion 6c is supported by the base 2. The supported portion 6c is fixedly press-fitted to the base 2, for example. The external connection portion 6d protrudes from the base 2 in the Z1 direction and is to be electrically connected to an external device (not shown).
The second fixed terminal 7 has the same shape as that of the first fixed terminal 6. The second fixed terminal 7 is supported by the base 2 at a position separated from the first fixed terminal 6 in the X direction. The second fixed terminal 7 includes a second contact support portion 7a, a second fixed contact 7b, a supported portion 7c, and an external connection portion 7d. Since the portions of the second fixed terminal 7 have the same configurations as those of the first fixed terminal 6, description thereof is omitted.
The movable contact piece 8 extends in the X direction. The movable contact piece 8 has a longitudinal direction corresponding to the X direction. The movable contact piece 8 is disposed closer to the Z2 direction side than the first fixed terminal 6 and the second fixed terminal 7. The movable contact piece 8 is disposed at a position to oppose the first contact support portion 6a and the second contact support portion 7a in the Z direction.
The movable contact piece 8 includes a pair of movable contacts 8a, 8b configured to contact the first fixed contact 6b and the second fixed contact 7b. In the following, as for the pair of movable contacts 8a, 8b for opening and closing, the contact to be contacted with the first fixed contact 6b is referred to as the first movable contact 8a, and the contact to be contacted with the second fixed contact 7b is referred to as the second movable contact 8b. The first movable contact 8a is disposed at a position opposite the first fixed contact 6b in the Z direction. The first movable contact 8a protrudes in the Z1 direction from the surface of the movable contact piece 8 directed in the Z1 direction. In the present embodiment, the first movable contact 8a is a separate body from the movable contact piece 8, but may be integrated with the movable contact piece 8.
The second movable contact 8b is disposed apart from the first movable contact 8a in the X direction. The second movable contact 8b is disposed at a position opposite the second fixed contact 7b in the Z direction. The second movable contact 8b protrudes in the Z1 direction from the surface of the movable contact piece 8 directed in the Z1 direction. In the present embodiment, the first movable contact 8a is a separate body from the movable contact piece 8, but may be integrated with the movable contact piece 8.
The movable contact piece 8 is disposed to be movable in a contact direction in which the first fixed contact 6b and the second fixed contact 7b come in contact with the pair of movable contacts 8a and 8b and in a separation direction in which the first fixed contact 6b and the second fixed contact 7b are separated from the pair of movable contacts 8a and 8b. The contact direction in the present embodiment corresponds to the Z1 direction, and the separation direction corresponds to the Z2 direction.
The movable member 9 is disposed movably in the Z1 direction (contact direction) and the Z2 direction (separation direction). The movable member 9 is disposed movably between the open position shown in
The movable member 9 is formed of an insulating material such as resin. The movable contact piece 8 is fixed to the movable member 9. In the present embodiment, the movable contact piece 8 is fixed to the movable member 9 by insert molding. Accordingly, the movable contact piece 8 moves integrally with the movable member 9 as the movable member 9 moves in the Z1 and Z2 directions.
Here, the base 2 includes a guide portion 21 and a recess 22. The guide portion 21 guides the movement of the movable member 9. In the present embodiment, the guide portion 21 is constituted by part of the recess 22 that is recessed in the Z2 direction. Specifically, the guide portion 21 is constituted by the inner surfaces of the recess 22. The guide portion 21 has a non-circular shape when viewed from the Z2 direction. The guide portion 21 is disposed closer to the Z1 direction side than the pair of movable contacts 8a, 8b. The guide portion 21 is disposed closer to the Z1 direction side than the first fixed contact 6b and the second fixed contact 7b. The guide portion 21 is disposed between the first fixed terminal 6 and the second fixed terminal 7 in the X direction. The guide portion 21 is open in the Z2 direction. The guide portion 21 is C-chamfered or R-chamfered at the end 21a in the Z2 direction, as enlarged in
The movable member 9 is guided by the guide portion 21 to move in the Z1 and Z2 directions. The movement of the movable member 9 in the X and Y directions is restricted by the guide portion 21. The sliding portion 9c is restricted by the guide portion 21 from rotating around its axis parallel to the Z direction.
The movable member 9 includes a shaft 9a, a spring mounting portion 9b, a sliding portion 9c, and a first spring housing portion 9d. The shaft 9a is substantially cylindrical and extends in the Z direction. The movable contact piece 8 is fixed to the shaft 9a. The spring mounting portion 9b is formed at the end of the shaft 9a in the Z2 direction. The spring mounting portion 9b is substantially cylindrical and extends in the Z2 direction. The spring mounting portion 9b has an outer diameter smaller than the outer diameter of the shaft 9a. To the spring mounting portion 9b, a contact spring 10 is mounted.
The sliding portion 9c is a part guided by the guide portion 21 and slides along the guide portion 21 in the Z direction. The sliding portion 9c is disposed inside the recess 22. The sliding portion 9c is located at the end of the shaft 9a in the Z1 direction. The sliding portion 9c is non-circular when viewed from the Z2 direction. The sliding portion 9c has a shape that conforms the shape of the guide portion 21. The sliding portion 9c is chamfered or rounded at the end 9f in the Z1 direction, as enlarged in
The first spring housing portion 9d is disposed opposite the recess 22 in the Z direction. The first spring housing portion 9d is recessed in the Z2 direction from the end of the shaft 9a in the Z1 direction. The first spring housing portion 9d is configured to house the return spring 11 partially. In the present embodiment, the first spring housing portion 9d is able to house one end of the return spring 11 in the Z2 direction.
The contact spring 10 is mounted to increase the contact pressure of the pair of movable contacts 8a, 8b against the first fixed contact 6b and the second fixed contact 7b. The contact spring 10 urges the movable member 9 in the Z1 direction. The contact spring 10 is supported by the spring mounting portion 9b. The contact spring 10 is disposed between a movable iron piece 4e and a shaft 9a, which will be described later.
The return spring 11 is disposed between the base 2 and the movable member 9 and urges the movable member 9 in the Z2 direction. The return spring 11 is disposed inside the recess 22. At least part of the return spring 11 is housed in the recess 22. The return spring 11 is surrounded by the recess 22 and the first spring housing portion 9d. The return spring 11 is positioned by the first spring housing portion 9d.
The drive device 4 is disposed apart from the contact device 3 in the Y direction. The drive device 4 is supported by the base 2. The drive device 4 uses electromagnetic force to move the movable member 9. The drive device 4 includes a coil 4a, a spool 4b, a fixed iron core 4c, a yoke 4d, and a movable iron piece 4e. The coil 4a is wound around the outer circumference of the spool 4b. The spool 4b extends in the Z direction. The fixed iron core 4c extends in the Z direction and is disposed inside the spool 4b. The yoke 4d is disposed to surround the coil 4a. The yoke 4d is connected to the fixed iron core 4c. The movable iron piece 4e has one end rotatably supported by the yoke 4d, and the other end connected to the spring mounting portion 9b of the movable member 9 to be in contact with the contact spring 10.
Next, the operations of the electromagnetic relay 100 will be described. While no voltage is applied to the coil 4a, the elastic force of the return spring 11 presses the movable member 9 in the Z2 direction, and the movable member 9 is positioned in the open position shown in
In the electromagnetic relay 100 configured as described above, the movable contact piece 8 is fixed to the movable member 9. In other words, since the movable contact piece 8 and the movable member 9 do not slide on each other, no wear powder is generated due to sliding between the movable contact piece 8 and the movable member 9. Therefore, it is possible to decrease the adhesion of abrasion powder to the first fixed contact 6b, the second fixed contact 7b, or the pair of movable contacts 8a, 8b. Further, since the guide portion 21 is disposed closer to the Z1 direction side than the first fixed contact 6b and the second fixed contact 7b, the guide portion 21 is at a position apart from the first fixed contact 6b, the second fixed contact 7b, and the pair of movable contacts 8a, 8b. As a result, it is possible to decrease the adhesion of the abrasion powder, which is generated by the sliding of the movable member 9 along the guide portion 21, to the first fixed contact 6b, the second fixed contact 7b, or the pair of movable contacts 8a, 8b. Furthermore, since the return spring 11 is disposed inside the guide portion 21, it is possible to decrease the adhesion of the abrasion powder, which is generated between the return spring 11 and the base 2, to the first fixed contact 6b, the second fixed contact 7b, or the pair of movable contacts 8a, 8b.
In the present embodiment, the return spring 11 is surrounded by the recess 22 and the first spring housing portion 9d. When the movable member 9 is in the open position, the end 9f of the sliding portion 9c is positioned closer to the Z1 direction side than the end 21a of the guide portion 21. Thus, the return spring 11 is not exposed to the space where the first fixed contact 6b, the second fixed contact 7b and the pair of movable contacts 8a, 8b are disposed. As such, it is possible to further decrease the adhesion of the abrasion powder generated by the sliding of the movable member 9 along the guide portion 21 to the first fixed contact 6b, the second fixed contact 7b, or the pair of movable contacts 8a, 8b.
One embodiment of the electromagnetic relay according to one aspect of the present invention has been described above, but the present invention is not limited to the above embodiment, and various modifications are possible without departing from the gist of the invention. For example, the configurations of the base 2, the contact device 3, and the drive device 4 may be changed.
The configuration of the movable member 9 may be changed. For example, as shown in
In addition, as shown in
As shown in
In the present embodiment, the movable contact piece 8 is fixed to the movable member 9 by insert molding, but the means for fixing the movable contact piece 8 to the movable member 9 is not limited to the embodiment.
In the example shown in
The movable member 9 may be formed of two or more materials. For example, in the case where the movable member 9 is composed of two components, the first component 36a and the second component 36b, the first component 36a and the second component 36b may be formed of different materials. For example, one of the first component 36a or the second component 36b may be formed of an insulating material such as resin, and the other of the first component 36a and the second component 36b may be formed of a metal material such as aluminum or stainless steel. In this case, it is preferable that the first component 36a disposed in the Z2 direction is formed of an insulating material, and the second component 36b disposed in the Z1 direction is formed of a metal material. As a result, heat generation of the contact device 3 can be reduced by the second component 36b while ensuring the insulation between the contact device 3 and the drive device 4 by the first component 36a.
In the above embodiment, the movable iron piece 4e directly contacts the contact spring 10 and presses the contact spring 10, but another configuration is possible in which the movable iron piece 4e indirectly presses the contact spring 10. For example, as shown in
The electromagnetic relay 100 may further include a permanent magnet for generating a magnetic field that causes a Lorentz force to act on the arcs generated between the pair of movable contacts 8a, 8b and the first fixed contact 6b and the second fixed contact 7b.
Number | Date | Country | Kind |
---|---|---|---|
2020-116254 | Jul 2020 | JP | national |
This application is the U.S. National Phase of International Application No. PCT/JP2021/022855, filed on Jun. 16, 2021. This application claims priority to Japanese Patent Application No. 2020-116254, filed Jul. 6, 2020. The contents of those applications are incorporated by reference herein in their entireties.
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/JP2021/022855 | 6/16/2021 | WO |