ELECTROMAGNETIC RELAY

Abstract

An electromagnetic relay includes a base, a first fixed terminal including a first fixed contact, a second fixed terminal including a second fixed contact, a movable contact piece, a movable member, and a return spring. The movable contact piece includes a pair of movable contacts configured to contact the first fixed contact and the second fixed contact. The movable member is movable with the movable contact piece in a contact direction and in a separation direction. 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 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.

Claims

1. An electromagnetic relay comprising: a base; a first fixed terminal including a first fixed contact, the first fixed terminal being supported by the base; a second fixed terminal including a second fixed contact, the second fixed terminal being supported by the base at a position separated from the first fixed terminal; a movable contact piece including a pair of movable contacts, the pair of movable contacts configured to contact the first fixed contact and the second fixed contact; a movable member to which the movable contact piece is fixed, the movable member being 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; and a return spring disposed between the base and the movable member, the return spring configured to urge the movable member in the separation direction, wherein the base includes a guide portion to guide 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, and the guide portion is disposed in the contact direction with respect to the first fixed contact and the second fixed contact.

2. The electromagnetic relay according to claim 1, wherein the sliding portion has a first end on a contact direction side and the guide portion has a second end on a separation direction side, the first end being positioned in the contact direction with respect to the second end.

3. The electromagnetic relay according to claim 1, wherein the base includes a recess recessed in the separation direction, the sliding portion and the return spring are disposed inside the recess, and the guide portion is constituted by part of the recess.

4. The electromagnetic relay according to claim 3, wherein the movable member includes a first spring housing portion opposite the recess, the first spring housing portion configured to house the return spring partially, and the return spring is surrounded by the recess and the first spring housing portion.

5. The electromagnetic relay according to claim 1, wherein one of the base or the movable member includes a positioning portion configured to position the return spring.

6. The electromagnetic relay according to claim 1, wherein the sliding portion has a first end on a contact direction side, the guide portion has a second end on a separation direction side, and at least one of the first end or the second end has a C-chamfered shape or an R-chamfered shape.

7. The electromagnetic relay according to claim 1, further comprising: a contact spring configured to urge the movable member in the contact direction, wherein the movable member includes a second spring housing portion configured to house the contact spring partially.

8. The electromagnetic relay according to claim 1, further comprising: 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, wherein the contact spring urges the movable member in the contact direction via the first spring bearing member.

9. The electromagnetic relay according to claim 1, further comprising: a second spring bearing member disposed between the return spring and the movable member, wherein the return spring urges the movable member in the separation direction via the second spring bearing member.

10. The electromagnetic relay according to claim 1 wherein the movable contact piece is fixed to the movable member by insert molding.

11. The electromagnetic relay according to claim 1, wherein the movable member is composed of at least two components including a first component and a second component, and the movable contact piece is fixed to the movable member in a state in which the movable contact piece is sandwiched between the first component and the second component.

12. The electromagnetic relay according to claim 11, further comprising: an elastic member disposed between the first component and the movable contact piece or between the second component and the movable contact piece, wherein the movable contact piece is fixed to the movable member via the elastic member.

13. The electromagnetic relay according to claim 11, wherein the first component and the second component are formed of different materials.

14. The electromagnetic relay according to claim 13, wherein the first component is formed of an insulating material, and the second component is formed of a metal material, the second component disposed in the contact direction with respect to the first component.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG. 1 is a schematic cross-sectional diagram of an electromagnetic relay, viewed from the X direction.

[0022] FIG. 2 is a schematic cross-sectional diagram of and around a contact device, viewed from the Y direction.

[0023] FIG. 3 is a partially enlarged diagram of FIG. 2.

[0024] FIG. 4 is a schematic cross-sectional diagram of and around the contact device, viewed from the Y direction.

[0025] FIG. 5 is a schematic cross-sectional diagram of and around a contact device according to a modification, viewed from the Y direction.

[0026] FIG. 6 is a schematic cross-sectional diagram of and around a contact device according to a modification, viewed from the Y direction.

[0027] FIG. 7 is a schematic cross-sectional diagram of and around a contact device according to a modification, viewed from the Y direction.

[0028] FIG. 8 is a partial cross-sectional diagram of a movable member according to a modification, viewed from the X direction.

[0029] FIG. 9 is a partial cross-sectional diagram of the movable member according to a modification, viewed from the Y direction.

[0030] FIG. 10 is a schematic cross-sectional diagram of an electromagnetic relay according to a modification, viewed from the X direction.

[0031] FIG. 11 is a schematic cross-sectional diagram of an electromagnetic relay according to a modification, viewed from the X direction.

DETAILED DESCRIPTION

[0032] 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 FIG. 1 is referred to as “Z direction,” the left-right direction as “Y direction,” the direction orthogonal to the plane of FIG. 1 as “X direction.” The Z direction toward the upper side in FIG. 1 is referred to as “Z2 direction,” and the Z direction toward the lower side as “Z1 direction.” However, these directions are defined for the convenience of description and are not intended to limit the directions of arrangements of an electromagnetic relay.

[0033] FIG. 1 is a schematic cross-sectional diagram of an electromagnetic relay 100, viewed from the X direction. The electromagnetic relay 100 includes a base 2, a contact device 3, and a drive device 4. The base 2 is formed of an insulating material such as resin. The base 2 is substantially rectangular when viewed from the Z direction. The base 2 supports the contact device 3 and the drive device 4. The contact device 3 and the drive device 4 are covered by a case (not shown) that is attached to the base 2.

[0034] FIG. 2 is a schematic cross-sectional diagram of and around the contact device 3, viewed from the Y direction. The contact device 3 is supported by the base 2. The contact device 3 includes a first fixed terminal 6, a second fixed terminal 7, a movable contact piece 8, a movable member 9, a contact spring 10, and a return spring 11. The first fixed terminal 6, the second fixed terminal 7, and the movable contact piece 8 are each a plate-shaped terminal and are formed of a conductive material such as copper.

[0035] As shown in FIG. 2, the first fixed terminal 6 is substantially L-shaped when viewed from the X direction. The first fixed terminal 6 may be substantially U-shaped for example, when viewed from the X direction. The first fixed terminal 6 is supported by the base 2.

[0036] 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).

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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 FIG. 2 and the closed position shown in FIG. 4. At the closed position, the pair of movable contacts 8a, 8b is in contact with the first fixed contact 6b and the second fixed contact. In the open position, the pair of movable contacts 8a, 8b is in separation from the first fixed contact 6b and the second fixed contact 7b.

[0043] 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.

[0044] 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 FIG. 3.

[0045] 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.

[0046] 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.

[0047] 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 FIG. 3. The end 9f is positioned closer to the Z1 direction side than the end 21a of the guide portion 21. Specifically, when the movable member 9 is in the open position and the closed position, the end 9f is positioned closer to the Z1 direction side than the end 21a of the guide portion 21.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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 FIG. 2. When a voltage is applied to the coil 4a to excite the drive device 4, the movable iron piece 4e is attracted to the fixed iron core 4c and rotates, and the movable member 9 is pressed via the contact spring 10 in the Z1 direction. Then, the movable member 9 moves to the closed position shown in FIG. 4 against the elastic force of the return spring 11. As the movable member 9 moves to the closed position, the movable contact piece 8 moves integrally with the movable member 9, and the pair of movable contacts 8a, 8b come into contact with the first fixed contact 6b and the second fixed contact 7b. Note that when the application of voltage to the coil 4a is stopped, the movable member 9 is moved in the Z2 direction to the open position by the elastic force of the return spring 11.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] The configuration of the movable member 9 may be changed. For example, as shown in FIG. 5, the movable member 9 may further include a second spring housing portion 9g. The second spring housing portion 9g is formed at the end of the shaft 9a in the Z2 direction. The second spring housing portion 9g is a recess recessed in the Z1 direction at the end of the shaft 9a located in the Z2 direction. The second spring housing portion 9g is configured to house the contact spring 10 partially. In the present embodiment, the second spring housing portion 9g is configured to house the end of the contact spring 10 in the Z1 direction. The second spring housing portion 9g surrounds at least a part of the contact spring 10 when the movable member 9 is in the open position. In this case, it is possible to decrease the adhesion of the abrasion powder, which is generated between the contact spring 10 and the movable member 9, to the first fixed contact 6b, the second fixed contact 7b, or the pair of movable contacts 8a, 8b.

[0057] In addition, as shown in FIG. 6, the first spring housing portion 9d may be omitted. In this case, one of the base 2 or the movable member 9 may include a positioning portion 30 for positioning the return spring 11. In the example shown in FIG. 6, the positioning portion 30 protrudes from the bottom of the recess 22 in the Z2 direction. Note that the positioning portion 30 may be formed to protrude in the Z1 direction from the shaft 9a of the movable member 9, or the bottom of the recess 22 may be recessed in the Z1 direction to form the positioning portion 30. In this case as well, when the movable member 9 is in the open position, the end 9f of the sliding portion 9c is preferably positioned closer to the Z1 direction side than the end 21a of the guide portion 21.

[0058] As shown in FIG. 7, the electromagnetic relay 100 may further include a first spring bearing member 32 disposed between the contact spring 10 and the movable member 9. In the example shown in FIG. 7, the first spring bearing member 32 is disposed on the end of the shaft 9a in the Z2 direction. The first spring bearing member 32 is formed of a material such as stainless steel, for example. The contact spring 10 may press the movable member 9 in the Z1 direction via the first spring bearing member 32. In this case, the generation of abrasion powder can be decreased as compared with the case where the contact spring 10 is brought into direct contact with the shaft 9a. Similarly, a second spring bearing member 34 may be disposed between the return spring 11 and the movable member 9 to urge the movable member 9 in the Z2 direction via the second spring bearing member 34. The second spring bearing member 34 may be disposed, for example, in the first spring housing portion 9d.

[0059] 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. FIG. 8 is a partial cross-sectional diagram of the movable member 9 according to a modification, viewed from the X direction. FIG. 9 is a partial cross-sectional diagram of the movable member 9 according to the modification, viewed from the Y direction. As shown in FIGS. 8 and 9, the movable member 9 may be composed of two or more components including a first component 36a and a second component 36b.

[0060] In the example shown in FIGS. 8 and 9, the movable member 9 is composed of two components: the first component 36a and the second component 36b. The movable contact piece 8 is fixed to the movable member 9 while being sandwiched between the first component 36a and the second component 36b in the Z direction. Specifically, the movable contact piece 8 may be fixed to the movable member 9 by snap-fitting or crimping between the first component 36a and the second component 36b in a state in which the movable contact piece 8 is sandwiched between the first component 36a and the second component 36b. In the case, in order to firmly fix the movable contact piece 8 to the movable member 9, an elastic member 38 may be disposed between the first component 36a and the movable contact piece 8 or between the second component 36b and the movable contact piece 8. The elastic member 38 is, for example, a highly rigid spring member. In the example shown in FIGS. 8 and 9, the elastic member 38 is disposed between the movable contact piece 8 and the first component 36a in the Z direction.

[0061] 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.

[0062] 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 FIG. 10, the movable iron piece 4e may indirectly press the contact spring 10 via an intervening member 40. Alternatively, as shown in FIG. 11, the contact spring 10 may be indirectly pressed via another separate component 42 that is connected to the movable iron piece 4e. In these cases, for example, the intervening member 40 or the separate component 42 formed of an insulating material facilitates to ensure the insulation between the contact device 3 and the drive device 4. Note that the intervening member 40 may be omitted when the separate component 42 is used.

[0063] 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.

REFERENCE NUMERALS

[0064] 2 Base [0065] 6 First fixed contact [0066] 7 Second fixed contact [0067] 8 Movable contact piece [0068] 8a, 8b A pair of movable contacts [0069] 9 Movable member [0070] 9c Sliding portion [0071] 9d First spring housing portion [0072] 9g Second spring housing portion [0073] 10 Return spring [0074] 11 Contact spring [0075] 21 Guide portion [0076] 22 Recess [0077] 32 Spring bearing member [0078] 34 Spring bearing member [0079] 36a First component [0080] 36b Second component [0081] 100 Electromagnetic relay [0082] Z1 Contact direction [0083] Z2 Separation direction