Patent Grant
11756759
This application is the U.S. National Phase of International Application No. PCT/JP2019/006140, filed on Feb. 19, 2019. This application claims priority to Japanese Patent Application No. 2018-157759, filed Aug. 24, 2018. The contents of that application are incorporated by reference herein in their entireties.
The present invention relates to an electromagnetic relay.
Conventionally, electromagnetic relays that open and close an electric circuit are known. The electromagnetic relay includes a fixed contact, a movable contact, a drive shaft, and an electromagnetic drive device. The electromagnetic drive includes a coil, a movable iron core connected to the drive shaft, and an urging member. The movable iron core is movable between an operating position and a cutoff position, and is urged toward the cutoff position by the urging member.
When a voltage is applied to the coil, the movable iron core moves from the cutoff position to the operating position against the elastic force of the urging member. As a result, the movable contact contacts the fixed contact via the drive shaft. When the application of the voltage to the coil is stopped, the movable iron core moves from the operating position to the cutoff position due to the elastic force of the urging member. As a result, the movable contact is separated from the fixed contact via the drive shaft.
For example, in Japanese Patent No. 5684650, the movable iron core comes into contact with an auxiliary yoke and is positioned at the cutoff position. Therefore, the movable iron core collides with the auxiliary yoke when moving from the operating position to the cutoff position. Since a portion where the movable iron core and the auxiliary yoke come into contact with each other is formed by a flat surface orthogonal to the drive shaft, a large impact force is generated in the axial direction when the movable shaft collides with the auxiliary yoke. If this impact force exceeds the elastic force of the urging member, the movable iron core may move to the operating position, causing a malfunction such as the movable contact contacting the fixed contact.
Further, Japanese Patent No. 5684650 discloses a configuration in which a magnet is disposed around the movable iron core to absorb vibration and impact of the movable iron core by an attractive force of the magnet. In this case, the manufacturing cost increases due to the increase in the number of parts. Similarly, Japanese Laid-Open Patent Application No. 2016-201286 discloses a configuration in which vibration and impact of the movable iron core are absorbed by a cushion rubber. In this case as well, the manufacturing cost increases due to the increase in the number of parts.
An object of the present invention is to improve a cutoff performance between the fixed contact and the movable contact. Another object of the present invention is to improve the cutoff performance between the fixed contact and the movable contact while reducing an increase in manufacturing cost.
(1) An electromagnetic relay according to one aspect of the present invention includes a fixed contact, a movable contact piece, a drive shaft, an electromagnetic drive device, and a positioning portion. The movable contact piece includes a movable contact disposed to face the fixed contact, and is movable in a first direction in contact with the fixed contact and in a second direction separating from the fixed contact. The drive shaft is connected to the movable contact piece and movable in the first direction and second direction together with the movable contact piece. The electromagnetic drive device includes a movable iron core that is integrally movably connected to the drive shaft, and switches between a contact state in which the movable contact comes into contact with the fixed contact and a separate state in which the movable contact is separated from the fixed contact by moving the drive shaft with the movable iron core. The positioning portion positions one of the drive shaft or the movable iron core in the separate state. One of the drive shaft or the movable iron core includes a first inclined portion that comes into contact with the positioning portion in the separate state.
In this electromagnetic relay, one of the drive shaft or the movable iron core includes the first inclined portion that comes into contact with the positioning portion in the separate state. For example, when the movable iron core includes the first inclined portion, when the movable contact is switched from the contact state to the separate state, the movable iron core moves in the second direction and the first inclined portion of the movable iron core collides with the positioning portion. Therefore, for example, the impact force generated in the axial direction can be reduced as compared with the case where the positioning portion and the first inclined portion collide with each other in planes perpendicular to the drive shaft. Therefore, in such case where the movable iron core collides with the positioning portion, the occurrence of malfunction such as the movable iron core moving in the first direction and the movable contact coming into contact with the fixed contact can be reduced. That is, it is possible to improve a cutoff performance between the fixed contact and the movable contact.
(2) Preferably, the first inclined portion is inclined in the first direction side or the second direction side toward the axis of the drive shaft. In this case, the first inclined portion can be realized with a simple configuration.
(3) Preferably, the first inclined portion includes a curved surface portion formed in a curved surface shape. Even in this case, the impact force generated in the axial direction can be reduced as compared with the case where the positioning portion and the first inclined portion collide with each other in planes perpendicular to the drive shaft.
(4) Preferably, the positioning portion includes a second inclined portion that comes into contact with the first inclined portion. The first inclined portion and the second inclined portion are inclined in the first direction side or the second direction side toward the axis of the drive shaft. In this case, since the second inclined portion of the positioning portion comes into contact with the first inclined portion, the impact force generated in the axial direction can be reduced as compared with the case where the positioning portion and the first inclined portion collide with each other in planes perpendicular to the drive shaft.
(5) Preferably, the electromagnetic relay further includes a contact case housing the fixed contact and movable contact. The contact case includes a tubular portion disposed to face the movable iron core. The positioning portion is formed on the tubular portion. The movable iron core includes the first inclined portion. In this case, since the positioning portion can be integrally formed with the contact case, the manufacturing cost can be reduced.
(6) Preferably, the electromagnetic drive device includes a bottomed tubular housing member that houses the movable iron core. The movable iron core includes the first inclined portion and is disposed to face a bottom portion of the housing member. The positioning portion is formed on the bottom of the housing member. In this case, since the positioning portion can be integrally formed with the housing member, the manufacturing cost can be reduced.
(7) Preferably, the electromagnetic relay further includes a contact case housing the fixed contact and movable contact. The drive shaft includes a first inclined portion. The contact case includes a tubular portion disposed to face the first inclined portion. The positioning portion is formed on the tubular portion. In this case, since the positioning portion can be integrally formed with the contact case, the manufacturing cost can be reduced.
(8) Preferably, the electromagnetic relay further includes a cover portion disposed to the second direction side with respect to the drive shaft. The positioning portion is disposed on the cover portion to face one end of the drive shaft. The drive shaft includes a first inclined portion. In this case, since the positioning portion can be integrally formed with the cover portion, the manufacturing cost can be reduced.
Hereinafter, embodiments of an electromagnetic relay according to one aspect of the present invention will be described with reference to the drawings.
In the following description, the direction in which an axis Ax of the drive shaft 4 extends is referred to as “axial direction”. Further, when referring to the drawings, an upper side in
The housing 2 includes a case 2a and a cover 2b. The case 2a has a substantially quadrangular box shape, and an upper part is separate. The cover 2b covers the upper part of the case 2a. The case 2a and the cover 2b are made of an insulating material. The contact device 3, the drive shaft 4, and the electromagnetic drive device 5 are housed inside the housing 2.
In the housing 2, a contact case 11 in which the contact device 3 is housed and a contact cover 12 that covers an upper part of the contact case 11 are disposed. The contact case 11 and the contact cover 12 are made of an insulating material.
The contact case 11 includes a bottom portion 11a, a tubular portion 11b, a first contact support portion 11c, and a second contact support portion 11d. The bottom portion 11a is formed in a rectangular shape and a plate shape. The longitudinal direction of the bottom portion 11a coincides with the left-right direction in
The tubular portion 11b extends in a cylindrical shape in the axial direction. The tubular portion 11b protrudes downward from the center of the bottom portion 11a and protrudes upward from the center of the bottom portion 11a. The tubular portion 11b includes a through hole 18 that axially penetrates the bottom portion 11a. The through hole 18 penetrates the center of the bottom portion 11a in the axial direction. The drive shaft 4 penetrates the through hole 18 in the axial direction. The tubular portion 11b does not necessarily need to be cylindrical.
The first contact support portion 11c is disposed to the left side with respect to the center of the bottom portion 11a in the longitudinal direction. The first contact support portion 11c is formed so as to protrude upward in a rectangular shape from the bottom portion 11a. The second contact support portion 11d is disposed to the right side with respect to the center of the bottom portion 11a in the longitudinal direction. The second contact support portion 11d is formed so as to protrude upward in a rectangular shape from the bottom portion 11a.
The contact cover 12 covers the upper part of the contact case 11. The contact cover 12 includes an arc extension wall 12a extending toward the bottom portion 11a. The arc extension wall 12a is made of, for example, a resin or a ceramic material such as aluminum oxide.
The contact device 3 includes a first fixed terminal 14, a second fixed terminal 15, a movable contact piece 16, and a contact piece holding portion 17. The first fixed terminal 14, the second fixed terminal 15, and the movable contact piece 16 are made of a conductive material.
The first fixed terminal 14 extends in the left-right direction and is supported in the housing 2 by the first contact support portion 11c of the contact case 11. The first fixed terminal 14 includes a first fixed contact 14a and a first external connection portion 14b. The first fixed contact 14a is disposed at an upper part of the first contact support portion 11c in the contact case 11. The first fixed contact 14a is an example of a fixed contact. The first external connection portion 14b protrudes from the case 2a in the left-right direction.
The second fixed terminal 15 extends in the left-right direction and is supported by the second contact support portion 11d of the contact case 11 in the housing 2. The second fixed terminal 15 includes a second fixed contact 15a and a second external connection portion 15b. As illustrated in
The movable contact piece 16 extends in the left-right direction in the contact case 11. The movable contact piece 16 is disposed to face the first fixed terminal 14 and the second fixed terminal 15. The movable contact piece 16 is disposed above the first fixed contact 14a and the second fixed contact 15a. The movable contact piece 16 includes a first movable contact 16a and a second movable contact 16b. The first movable contact 16a is disposed to face the first fixed contact 14a and is contactable with the first fixed contact 14a. The second movable contact 16b is disposed to face the second fixed contact 15a and is contactable with the second fixed contact 15a. The first movable contact 16a and the second movable contact 16b are examples of movable contacts.
The movable contact piece 16 is movable in the contact direction Z1 in contact with the first fixed contact 14a and the second fixed contact 15a, and the separation direction Z2 separating from the first fixed contact 14a and the second fixed contact 15a.
The contact direction Z1 is the direction in which the first movable contact 16a and the second movable contact 16b come into contact with the first fixed contact 14a and the second fixed contact 15a (downward in
The contact piece holding portion 17 holds the movable contact piece 16 via the drive shaft 4. The contact piece holding portion 17 connects the movable contact piece 16 and the drive shaft 4. The contact piece holding portion 17 includes a holder 24 and a contact spring 25. The movable contact piece 16 is sandwiched between an upper portion of the holder 24 and a flange portion 4a of the drive shaft 4 in the axial direction. The contact spring 25 is disposed between a bottom of the holder 24 and the flange portion 4a of the drive shaft 4, and urges the drive shaft 4 and the movable contact piece 16 toward the separation direction Z2.
The drive shaft 4 extends along the contact direction Z1 and the separation direction Z2. The drive shaft 4 is connected to the movable contact piece 16 via the contact piece holding portion 17. The drive shaft 4 movable together with the movable contact piece 16 in the contact direction Z1 and the separation direction Z2.
The electromagnetic drive device 5 moves the drive shaft 4 in the contact direction Z1 and the separation direction Z2. As a result, the electromagnetic drive device 5 switches between a contact state in which the first movable contact 16a and the second movable contact 16b contact the first fixed contact 14a and the second fixed contact 15a (see
The electromagnetic drive device 5 includes a coil 32, a spool 33, a movable iron core 34, a fixed iron core 35, an urging member 36, and a yoke 37.
The coil 32 is mounted on an outer circumference of the spool 33. The spool 33 includes a housing portion 33a. The housing portion 33a is provided on an inner peripheral portion of the spool 33. The housing portion 33a has a cylindrical shape and extends along the axial direction.
The movable iron core 34 is disposed in the housing portion 33a. The movable iron core 34 is disposed to face the tubular portion 11b of the contact case 11. The movable iron core 34 is, for example, cylindrical, and the drive shaft 4 penetrates the center in the axial direction and is integrally movably connected to the drive shaft 4. The movable iron core 34 is movable in the axial direction together with the drive shaft 4 between a cutoff position illustrated in
The movable iron core 34 includes a first inclined portion 34a. The first inclined portion 34a is formed on the surface of the movable iron core 34 in the separation direction Z2 side. The first inclined portion 34a is disposed to face the positioning portion 6 and is contactable with the positioning portion 6. The first inclined portion 34a inclines in the contact direction Z1 side toward the axis Ax of the drive shaft 4.
The fixed iron core 35 is disposed in the housing portion 33a to face the movable iron core 34 on the contact direction Z1 side with respect to the movable iron core 34. The fixed iron core 35 is fixed to the yoke 37.
The urging member 36 is, for example, a coil spring, and is disposed between the movable iron core 34 and the fixed iron core 35. The urging member 36 urges the movable iron core 34 toward the separation direction Z2. Therefore, the urging member 36 is disposed between the movable iron core 34 and the fixed iron core 35 in a compressed state.
The yoke 37 includes a first yoke 37a and a second yoke 37b. The first yoke 37a has a plate shape and is disposed between the bottom portion 11a of the contact case 11 and the spool 33. The first yoke 37a overlaps a lower portion of the tubular portion 11b in the left-right direction. The first yoke 37a is connected to the fixed iron core 35. The second yoke 37b has a substantially U shape, and the bottom portion is disposed below the spool 33. The upper ends of both sides of the second yoke 37b are connected to the first yoke 37a.
The positioning portion 6 is disposed at the end portion of the contact case 11 in the contact direction Z1 side of the tubular portion 11b. In the present embodiment, the positioning portion 6 positions the movable iron core 34 in the separate state. Specifically, as illustrated in
The positioning portion 6 includes a second inclined portion 6a. The second inclined portion 6a is formed on the surface of the tubular portion 11b of the contact case 11 in the contact direction Z1 side. Second inclined section 6a has a shape corresponding to the first inclined portion 34a of the movable iron core 34. Specifically, the second inclined portion 6a inclines in the contact direction Z1 side toward the axis Ax of the drive shaft 4. That is, the second inclined portion 6a has a tapered shape that tapers toward the axis Ax of the drive shaft 4. The second inclined portion 6a comes into contact with the first inclined portion 34a of the movable iron core 34 in the separate state. As a result, the movable iron core 34 is positioned at the cutoff position. As illustrated in
Next, the operation of the electromagnetic relay 100 will be described.
When the application of the voltage to the coil 32 is stopped, the movable iron core 34 moves from the operating position to the cutoff position by the elastic force of the urging member 36, and the first movable contact 16a and the second movable contact 16b separate from the first fixed contact 14a and the second fixed contact 15a. When the movable iron core 34 moves from the operating position to the cutoff position, the movable iron core 34 collides with the positioning portion 6 and an impact force is generated in the axial direction. If this collision force exceeds the elasticity of the urging member 36, the movable iron core 34 may move to the operating position, and the first movable contact 16a and the second movable contact 16b may contact the first fixed contact 14a and the second fixed contact 15a.
In the present embodiment, when the application of the voltage to the coil 32 is stopped and the movable iron core 34 moves from the operating position to the cutoff position, the first inclined portion 34a of the movable iron core 34 and the second inclined portion 6a of the positioning portion 6 collides with each other. As a result, the impact force generated in the axial direction according to the inclination angles of the first inclined portion 34a and the second inclined portion 6a is distributed as vectors, so that the impact force generated in the axial direction can be reduced as compared with the case where the movable iron core 34 and the positioning portion 6 collide with each other in planes perpendicular to the drive shaft 4.
Therefore, in such case where the movable iron core 34 collides with the positioning portion 6, the occurrence of malfunction such as the movable iron core 34 moving to the operating position and the first movable contact 16a and the second movable contact 16b coming into contact with the first fixed contact 14a and the second fixed contact 15a can be reduced. As a result, it is possible to improve the cutoff performance between the contacts at the first fixed contact 14a and the first movable contact 16a, and at the second fixed contact 15a and the second movable contact 16b. Further, since the impact of the movable iron core 34 can be reduced without the use of magnets, cushion rubber, or other components, the manufacturing cost can also be reduced.
Although the embodiment of the electromagnetic relay according to one aspect of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the invention. For example, the configuration of the electromagnetic drive device 5 may be changed. The shape or arrangement of the coil 32, the spool 33, the movable iron core 34, the urging member 36, or the yoke 37 may be changed. The shape or arrangement of the housing 2, the contact device 3, the contact case 11, and the contact cover 12 may be changed.
In particular, the shapes of the positioning portion 6 and the first inclined portion 34a of the movable iron core 34 are not limited to the above-described embodiment. The shape of the first inclined portion 34a of the positioning portion 6 and the movable iron core 34 may be any shape that can reduce the impact force generated in the axial direction when the positioning portion 6 and the first inclined portion 34a collide with each other.
The positioning portion 6 is formed on the bottom portion 40a of the housing member 40. The positioning portion 6 includes a second inclined portion 6a. The second inclined portion 6a is formed on the bottom surface on the contact direction Z1 side. The second inclined portion 6a is formed to be inclined in the separation direction Z2 side toward the axis Ax of the drive shaft 4.
The first inclined portion 34a of the movable iron core 34 is formed on the surface in the separation direction Z2 side, as in the above embodiment. The first inclined portion 34a is disposed to face the positioning portion 6 and is contactable with the positioning portion 6. The first inclined portion 34a has a shape corresponding to the second inclined portion 6a of the positioning portion 6. The first inclined portion 34a is formed to be inclined in the separation direction Z2 side toward the axis Ax of the drive shaft 4. In the third modification, the same effect as that of the above embodiment can be obtained.
The drive shaft 4 includes a first inclined portion 4b that comes into contact with the positioning portion 6. The first inclined portion 4b inclines in the separation direction Z2 side toward the axis Ax of the drive shaft 4. The first inclined portion 4b is disposed to face the tubular portion 111b of the contact case 111.
The positioning portion 6 positions the drive shaft 4 in the separate state. The positioning portion 6 is formed on the tubular portion 111b of the contact case 111. The positioning portion 6 includes a second inclined portion 6a. The second inclined portion 6a is formed on a peripheral edge of the tubular portion 111b of the through hole 118 in the contact direction Z1 side. The second inclined portion 6a inclines in the separation direction Z2 side toward the axis Ax of the drive shaft 4. In the fourth variation, when the positioning portion 6 positions the drive shaft 4, the impact force generated in the axial direction can be reduced as compared with the case where the drive shaft 4 and the positioning portion 6 collide with each other in planes perpendicular to the drive shaft 4.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2018-157759 | Aug 2018 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2019/006140 | 2/19/2019 | WO |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2020/039615 | 2/27/2020 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 7626288 | Protze | Dec 2009 | B2 |
| 8749331 | Kashimura | Jun 2014 | B2 |
| 20070241847 | Yamamoto et al. | Oct 2007 | A1 |
| 20120092098 | Choi | Apr 2012 | A1 |
| 20130228552 | Kashimura et al. | Sep 2013 | A1 |
| 20150054605 | Kubono | Feb 2015 | A1 |
| 20160181038 | Shimizu | Jun 2016 | A1 |
| 20160300676 | Sakai et al. | Oct 2016 | A1 |
| 20180223783 | Bohmann | Aug 2018 | A1 |
| Number | Date | Country |
|---|---|---|
| 2006-310250 | Nov 2006 | JP |
| 2012-089491 | May 2012 | JP |
| 5684650 | Mar 2015 | JP |
| 2016-201286 | Dec 2016 | JP |
| Entry |
|---|
| The International Search Report of International Application No. PCT/JP2019/006140 dated May 28, 2019. |
| The Written Opinion of the International Searching Authority of International Application No. PCT/JP2019/006140 dated May 28, 2019. |
| Number | Date | Country | |
|---|---|---|---|
| 20210327671 A1 | Oct 2021 | US |
