Electromagnetic relays

Abstract

To suppress deterioration in contact pressure between a fixed contact point and a movable contact point by an electromagnetic repulsive force in an electromagnetic relay.SOLUTION: An electromagnetic relay comprises: a case containing a base; a first fixing terminal containing a first fixing contact point; a second fixing terminal containing a second fixing contact point; a movable contact piece; and a driving device. The movable contact piece contains a first movable contact point and a second movable contact point. The driving device makes the movable contact piece move in a movement direction including a first direction and a second direction. The first fixing terminal includes: a first contact support part; a first external part connection part; a first extension part; and a first connection part. The first contact support part is extended in parallel with a third direction to the first movable contact point from the second movable contact point, and the first fixing contact point is arranged. The first external part connection part is extended in a fourth direction orthogonal to the first direction and the third direction over an external part from an internal part of the case, and is overlapped with the first fixing contact point in the movement direction of the movable contact piece. The first extension part is extended in the third direction from the first external part connection part in the internal part of the case. The first connection part connects the first contact support part and the first extension part.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an electromagnetic relay.

Background Art

[0002] When a large current such as a short-circuit current flows in a state where a movable contact contacts a fixed contact, an electromagnetic repulsive force in a direction to separate the contacts is generated in an electromagnetic relay, and there is a problem that the contact pressure of the contacts decreases. For example, the electromagnetic relay disclosed in Patent Document 1 attempts to suppress a decrease in contact pressure due to electromagnetic repulsive force by providing a telescopic member that expands and contracts according to an induced magnetic field generated when a current flows between a fixed contact and a movable contact.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to suppress a decrease in contact pressure between a fixed contact and a movable contact due to electromagnetic repulsive force in an electromagnetic relay.

Means for Solving the Problems

[0005] An electromagnetic relay according to one aspect of the present invention comprises a case, a first fixed terminal, a second fixed terminal, a movable contact piece, and a drive device. The case includes a base. The first fixed terminal includes a first fixed contact. The second fixed terminal is positioned away from the first fixed terminal and supported by the base. The second fixed terminal includes a second fixed contact. The movable contact piece includes a first movable contact facing the first fixed contact and a second movable contact facing the second fixed contact. The drive device moves the movable contact piece in a direction of movement that includes a first direction in which the first movable contact approaches the first fixed contact and a second direction in which the first movable contact moves away from the first fixed contact. The first fixed terminal includes a first contact support portion, a first external connection portion, a first extension portion, and a first connection portion. The first contact support portion extends parallel to a third direction from the second movable contact toward the first movable contact, and the first fixed contact is positioned thereon. The first external connection portion extends from the inside to the outside of the case in a fourth direction perpendicular to the first and third directions, is positioned in a second direction relative to the movable contact piece, and overlaps with the first fixed contact in the direction of movement of the movable contact piece. The first extension portion extends from the first external connection portion in a third direction inside the case. The first connection portion connects the first contact support portion and the first extension portion.

[0006] In this electromagnetic relay, when energized, the direction of the current flowing through the movable contact piece and the direction of the current flowing through the first extension are opposite, so a Lorentz force is generated that presses the first movable contact against the first fixed contact. As a result, in the electromagnetic relay, the decrease in contact pressure between the first fixed contact and the first movable contact due to electromagnetic repulsion can be suppressed.

[0007] The first connection portion may overlap with the base in the fourth direction. In this case, it is possible to suppress the increase in size of the electromagnetic relay in the direction parallel to the first direction.

[0008] The first connection part may be located outside the base. In this case, the first connection part can be prevented from being affected by the arc generated between the first fixed contact and the first movable contact. In addition, the heat generated by the first fixed terminal can be dissipated from the first connection part to the outside of the base.

[0009] The base may include a first support wall that supports the first contact support from a first direction. In this case, when the first movable contact contacts the first fixed contact, the movement of the first contact support in the first direction can be suppressed.

[0010] The base may include a second support wall that supports the first external connection and the first extension from a second direction. In this case, when a Lorentz force is generated that presses the first external connection and the first extension in a second direction due to the direction of the current flowing through the movable contact piece being opposite to the direction of the current flowing through the first extension, it is possible to suppress the movement of the first external connection and the first extension in the second direction.

[0011] The first extension may be located away from the space in which the first fixed contact is housed. In this case, the first extension can be prevented from being affected by the arc generated between the first fixed contact and the first movable contact.

[0012] The second fixed terminal may include a second contact support portion, a second external connection portion, a second extension portion, and a second connection portion. The second contact support portion may extend parallel to the third direction, and the second fixed contact may be positioned on it. The second external connection portion may extend in a fourth direction from the inside to the outside of the case, be positioned in a second direction relative to the movable contact piece, and may overlap with the second fixed contact in the direction of movement of the movable contact piece. The second extension portion may extend inside the case from the second external connection portion in a fifth direction opposite to the third direction. The second connection portion may connect the second contact support portion and the second extension portion. In this case, the direction of the current flowing through the movable contact piece and the direction of the current flowing through the second extension portion are opposite, so a Lorentz force is generated that presses the second movable contact against the second fixed contact. This makes it possible to suppress the decrease in contact pressure between the second fixed contact and the second movable contact due to electromagnetic repulsion in the electromagnetic relay. [Effects of the Invention]

[0013] According to the present invention, in an electromagnetic relay, it is possible to suppress the decrease in contact pressure between the fixed contact and the movable contact due to electromagnetic repulsion. [Brief explanation of the drawing]

[0014] [Figure 1] This is a perspective view of an electromagnetic relay. [Figure 2] This is a perspective view of an electromagnetic relay with the cover removed. [Figure 3] This is a perspective view of a contact device. [Figure 4] This is a view of the contact device from above. [Figure 5] This is a partial cross-sectional view obtained by cutting the area around the first movable contact point with a plane perpendicular to the left-right direction. [Modes for carrying out the invention]

[0015] Hereinafter, an embodiment of an electromagnetic relay 1 according to one aspect of the present invention will be described with reference to the drawings. When referring to the drawings, X1 direction will be described as the left direction, X2 direction as the right direction, Y1 direction as the front direction, Y2 direction as the rear direction, Z1 direction as the up direction, and Z2 direction as the down direction. These directions are defined for the convenience of explanation and do not limit the orientation of the electromagnetic relay 1.

[0016] In this embodiment, the Y2 direction is an example of a first direction, the Y1 direction is an example of a second direction, the X2 direction is an example of a third direction, the Z1 and Z2 directions are examples of a fourth direction, and the X1 direction is an example of a fifth direction.

[0017] As shown in Figures 1 and 2, the electromagnetic relay 1 comprises a case 2, a contact device 3, and a drive device 4.

[0018] Case 2 is formed in a box shape. Case 2 is made of an insulating material such as resin and includes a base 21 and a cover 22. The base 21 supports the contact device 3 and the drive device 4.

[0019] As shown in FIGS. 2 and 5, the base 21 includes a bottom 21a, outer walls 21b to 21e, and an inner wall 21f. The bottom 21a extends in a direction orthogonal to the vertical direction. The outer wall 21b extends upward from the front edge of the bottom 21a. The outer wall 21c extends upward from the rear edge of the bottom 21a. The outer wall 21d extends upward from the left edge of the bottom 21a. The outer wall 21e extends upward from the right edge of the bottom 21a. The inner wall 21f extends upward from the bottom 21a. The inner wall 21f extends in the left-right direction between the outer walls 21d and 21e. The inner wall 21f is disposed between the contact device 3 and the drive device 4 in the front-rear direction. The inner wall 21f is an example of the first support wall, and the outer wall 21b is an example of the second support wall.

[0020] The cover 22 opens downward and is attached to the outer walls 21b to 21e of the base 21 so as to cover the bottom 21a of the base 21 from above. The contact device 3 and the drive device 4 are housed in the case 2.

[0021] As shown in FIGS. 3 and 4, the contact device 3 includes a first fixed terminal 11, a second fixed terminal 12, and a movable contact piece 13. In the following description, the first fixed terminal 11 and the second fixed terminal 12 may be referred to as fixed terminals 11, 12.

[0022] The fixed terminals 11, 12 are formed of a conductive material such as copper. The fixed terminals 11, 12 are plate-shaped terminals and have a bent shape. The fixed terminals 11, 12 have a U shape when viewed from the left-right direction. The fixed terminals 11, 12 are supported by the base 21. The fixed terminals 11, 12 are inserted into the base 21 from below the base 21. The fixed terminals 11, 12 are press-fitted and fixed to the base 21.

[0023] The first fixed terminal 11 includes a first fixed contact 11a, a first contact support portion 11b, a first external connection portion 11c, a first extension portion 11d, and a first connection portion 11e.

[0024] The first fixed contact 11a is crimped and fixed to the first contact support portion 11b. The first fixed contact 11a may be integrated with the first fixed terminal 11.

[0025] The first contact support portion 11b is on which the first fixed contact 11a is positioned. The first contact support portion 11b supports the first fixed contact 11a. The first contact support portion 11b extends in a direction perpendicular to the front-rear direction. As shown in Figure 5, the first contact support portion 11b is supported from the rear by the inner wall 21f of the base 21. In detail, the rear surface of the first contact support portion 11b is positioned in contact with the front surface of the inner wall 21f. The rearward movement of the first contact support portion 11b is restricted by the inner wall 21f.

[0026] The first external connection portion 11c extends vertically from the inside to the outside of the case 2. The lower end of the first external connection portion 11c protrudes downward from the bottom 21a of the base 21 and is electrically connected to an external device (not shown). Within the case 2, the first external connection portion 11c is separated from the space in which the first fixed contact 11a is housed. The first external connection portion 11c is supported from the front by the outer wall 21b of the base 21.

[0027] More specifically, as shown in Figure 5, the first external connection portion 11c is housed in a retaining groove 21g formed in the outer wall 21b, except for the portion that protrudes downward from the bottom 21a of the base 21. The retaining groove 21g opens downward and has a shape that is recessed from bottom to top. The movement of the first external connection portion 11c in the front-rear direction is restricted by the retaining groove 21g. The rear surface of the first external connection portion 11c is covered by the retaining groove 21g in the outer wall 21b of the base 21 inside the case 2.

[0028] The first external connection portion 11c is positioned in front of the movable contact piece 13. Inside the case 2, the first external connection portion 11c faces the first contact support portion 11b in the front-rear direction. The first external connection portion 11c includes an overlapping portion 32 that overlaps with the first fixed contact 11a in the front-rear direction. The overlapping portion 32 is positioned near the upper end of the first external connection portion 11c.

[0029] The first extension portion 11d extends to the right from the first external connection portion 11c inside the case 2. In this embodiment, the first extension portion 11d extends to the right from the overlapping portion 32. The first extension portion 11d is formed on the same plane as the first external connection portion 11c. The first extension portion 11d faces the first contact support portion 11b in the front-rear direction. The first extension portion 11d is supported from the front by the outer wall 21b of the base 21. The first extension portion 11d is housed in the retaining groove 21g. The front surface of the first extension portion 11d is positioned in contact with the retaining groove 21g of the outer wall 21b and is supported by the retaining groove 21g. The movement of the first extension portion 11d in the front-rear direction is restricted by the retaining groove 21g. The rear surface of the first extension portion 11d is covered by the retaining groove 21g of the outer wall 21b of the base 21. The first extension portion 11d is located inside the case 2, away from the space in which the first fixed contact 11a is housed.

[0030] As shown in Figure 3, the first extension 11d includes a first portion 35 and a second portion 36. The first portion 35 extends to the right from the overlapping portion 32. The second portion 36 extends downward from the right end of the first portion 35. The second portion 36 is separated from the first external connection portion 11c in the left-right direction.

[0031] The first connecting portion 11e connects the first contact support portion 11b and the first extension portion 11d. The first connecting portion 11e extends in the front-rear direction. The first connecting portion 11e extends rearward from the lower end of the second portion 36 of the first extension portion 11d and is connected to the lower end of the first contact support portion 11b. The dimensions of the first connecting portion 11e in the left-right direction are the same as the dimensions of the second portion 36 in the left-right direction.

[0032] As shown in Figure 5, the first connecting portion 11e overlaps with the base 21 in the vertical direction. The first connecting portion 11e is located outside the base 21. The first connecting portion 11e is located below the bottom 21a of the base 21. In this embodiment, the first connecting portion 11e is located outside the case 2 and is exposed to the outside from the case 2.

[0033] The second fixed terminal 12 is positioned to the left of the first fixed terminal 11. The second fixed terminal 12 includes a second fixed contact 12a, a second contact support portion 12b, a second external connection portion 12c, a second extension portion 12d, and a second connection portion 12e. Since the second fixed terminal 12 has a left-right symmetrical shape with respect to the first fixed terminal 11, a simplified explanation will suffice.

[0034] The second fixed contact 12a is crimped and fixed to the second contact support portion 12b. The second fixed contact 12a may be integrated with the second fixed terminal 12. The second contact support portion 12b extends in the left-right direction, and the second fixed contact 12a is positioned thereon. The second external connection portion 12c extends vertically from the inside to the outside of the case 2. The second external connection portion 12c is positioned in front of the movable contact piece 13. The second external connection portion 12c overlaps with the second fixed contact 12a in the front-rear direction. The first external connection portion 11c protrudes downward from the bottom portion 21a of the base 21 and is electrically connected to an external device (not shown). The second extension portion 12d extends to the left from the second external connection portion 12c inside the case 2. The second connection portion 12e connects the second contact support portion 12b and the second extension portion 12d.

[0035] The movable contact piece 13 is a plate-shaped terminal made of a conductive material such as copper. The movable contact piece 13 is positioned in front of the fixed terminals 11 and 12. The movable contact piece 13 is approximately T-shaped when viewed from the front-to-back direction. The movable contact piece 13 includes a first movable contact 13a, a second movable contact 13b, an upper and lower extension portion 13c, and a left and right extension portion 13d.

[0036] The first movable contact 13a and the second movable contact 13b are crimped and fixed to the movable contact piece 13. The first movable contact 13a and the second movable contact 13b are located on the rear surface of the left and right extensions 13d. The first movable contact 13a faces the first fixed contact 11a in the front-rear direction. The first movable contact 13a is capable of contacting the first fixed contact 11a. The second movable contact 13b is located to the left of the first movable contact 13a. The second movable contact 13b faces the second fixed contact 12a in the front-rear direction. The second movable contact 13b is capable of contacting the second fixed contact 12a. Note that the first movable contact 13a and the second movable contact 13b may be integrated with the movable contact piece 13.

[0037] The vertical extension portion 13c extends in the vertical direction, and its upper part is connected to the drive device 4. The left and right extension portion 13d extends from the lower part of the vertical extension portion 13c in the left and right directions.

[0038] The drive unit 4 moves the movable contact piece 13 in a direction in which the first movable contact 13a approaches the first fixed contact 11a, and in a direction in which the first movable contact 13a moves away from the first fixed contact 11a. The drive unit 4 also moves the movable contact piece 13 in a direction in which the second movable contact 13b approaches the second fixed contact 12a, and in a direction in which the second movable contact 13b moves away from the second fixed contact 12a. In this embodiment, the drive unit 4 moves the movable contact piece 13 in the front-rear direction. The front-rear direction is an example of the direction in which the movable contact piece 13 moves.

[0039] As shown in Figure 2, the drive unit 4 includes a spool 41, a coil 42, a yoke 43, a movable iron piece 44, a resin member 45, a return spring 46, and a fixed iron core (not shown).

[0040] The spool 41 is cylindrical and extends in the front-rear direction. The coil 42 is wound around the outer circumference of the spool 41. The coil 42 is positioned above the fixed terminals 11 and 12. The yoke 43 has an L-shaped bend. The yoke 43 includes a connecting portion 43a and an extending portion 43b. The connecting portion 43a is positioned behind the spool 41 and is connected to the fixed iron core. The extending portion 43b extends forward from the upper end of the connecting portion 43a so as to cover the top of the coil 42.

[0041] The movable iron piece 44 is positioned in front of the fixed iron core. The movable iron piece 44 is rotatably supported by the yoke 43 at the front end of the extension portion 43b. The resin member 45 insulates the movable iron piece 44 from the movable contact piece 13. The resin member 45 connects the movable iron piece 44 and the movable contact piece 13. In detail, the movable iron piece 44 and the movable contact piece 13 are insert-molded into the resin member 45. As a result, the resin member 45 and the movable contact piece 13 rotate integrally with the movable iron piece 44 in response to the rotation of the movable iron piece 44.

[0042] The return spring 46 is a coil spring and extends in the front-rear direction. The front end of the return spring 46 is connected to the movable iron piece 44, and the rear end is connected to the yoke 43. The return spring 46 biases the movable contact piece 13 in the forward direction via the movable iron piece 44 and the resin member 45. That is, the return spring 46 biases the movable contact piece 13 in the direction in which the first movable contact 13a moves away from the first fixed contact 11a, and the second movable contact 13b moves away from the second fixed contact 12a.

[0043] Next, the operation of the electromagnetic relay 1 will be described. When no voltage is applied to the coil 42, the first movable contact 13a is separated from the first fixed contact 11a and the second movable contact 13b is separated from the second fixed contact 12a due to the elastic force of the return spring 46. When voltage is applied to the coil 42 and it is energized, the movable iron piece 44 is attracted to the fixed iron core by electromagnetic force, causing the movable iron piece 44 to rotate against the elastic force of the return spring 46. As a result, the movable contact piece 13 moves backward, and the first movable contact 13a contacts the first fixed contact 11a and the second movable contact 13b contacts the second fixed contact 12a. When the application of voltage to the coil 42 is stopped, the movable iron piece 44 rotates due to the elastic force of the return spring 46. As a result, the movable contact piece 13 moves forward, causing the first movable contact 13a to separate from the first fixed contact 11a, and the second movable contact 13b to separate from the second fixed contact 12a.

[0044] Figures 3 and 4 schematically show the direction of current flow with arrows. In this embodiment, when energized, current flows from the first fixed contact 11a to the first movable contact 13a. In this case, at the first fixed terminal 11, current flows in the order of the first external connection part 11c, the first extension part 11d, the first connection part 11e, the first contact support part 11b, and the first fixed contact 11a, and at the movable contact piece 13, current flows from the first movable contact 13a to the second movable contact 13b. Also, at the second fixed terminal 12, current flows in the order of the second fixed contact 12a, the second contact support part 12b, the second connection part 12e, the second extension part 12d, and the second external connection part 12c.

[0045] Therefore, when energized, the direction of the current flowing through the overlapping portion 32 of the first external connection portion 11c and the first portion 35 of the first extension portion 11d is opposite to the direction of the current flowing through the movable contact piece 13. As a result, a Lorentz force is generated that presses the first movable contact 13a against the first fixed contact 11a, thereby suppressing the decrease in contact pressure between the first fixed contact 11a and the first movable contact 13a due to electromagnetic repulsion.

[0046] Similarly, since the direction of the current flowing through the movable contact piece 13 and the direction of the current flowing through the second extension portion 12d are opposite, a Lorentz force is generated that presses the second movable contact 13b against the second fixed contact 12a. This makes it possible to suppress the decrease in contact pressure between the second fixed contact 12a and the second movable contact 13b due to electromagnetic repulsion.

[0047] Furthermore, since the first connection portion 11e of the first fixed terminal 11 is exposed to the outside from the case 2, the heat generated by the first fixed terminal 11 can be dissipated to the outside of the case 2 from the first connection portion 11e.

[0048] Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the invention.

[0049] The configurations of the contact device 3 and the drive device 4 may be changed. The drive device 4 may have a plunger-type structure. The configuration of case 2 may be changed.

[0050] The shape of the first fixed terminal 11 may be changed. For example, the first connecting portion 11e may extend rearward from the right end of the first extension portion 11d and be connected to the right end of the first contact support portion 11b. In this case, the second portion 36 of the first extension portion 11d may be omitted. The first connecting portion 11e may extend rearward from the upper end of the first extension portion 11d toward the first contact support portion 11b. A part of the first external connecting portion 11c, the first extension portion 11d, and the first connecting portion 11e may be arranged in the space in which the first fixed contact 11a is housed. [Explanation of symbols]

[0051] 1 Electromagnetic relay 2 cases 4. Drive system 11 1st fixed terminal 11a 1st fixed contact 11b 1st contact support part 11c First external connection 11d 1st extension section 11e First connection 12 2nd fixed terminal 12a 2nd fixed contact 13 Movable contact piece 13a 1st movable contact 13b 2nd movable contact 21 Base

Claims

1. The case includes the bass, A first fixed terminal, which includes a first fixed contact and is supported on the base, A second fixed contact is included, which is positioned away from the first fixed terminal and is supported by the base, A movable contact piece including a first movable contact facing the first fixed contact and a second movable contact facing the second fixed contact, A drive device that moves the movable contact piece in a movement direction including a first direction in which the first movable contact approaches the first fixed contact and a second direction in which the first movable contact moves away from the first fixed contact, Equipped with, The first fixed terminal is, A first contact support portion extends parallel to the third direction from the second movable contact toward the first movable contact, and the first fixed contact is arranged therein. A first external connection portion extends from the inside to the outside of the case in a fourth direction perpendicular to the first and third directions, is positioned in the second direction relative to the movable contact piece, and overlaps with the first fixed contact in the direction of movement of the movable contact piece, Inside the case, a first extension portion extends from the first external connection portion in the third direction, A first connecting portion that connects the first contact support portion and the first extension portion, Includes, The first contact support portion, the first external connection portion, the first extension portion, and the first connection portion are integrally formed as a single terminal. Electromagnetic relay.

2. The first connecting portion overlaps with the base in the fourth direction, The electromagnetic relay according to claim 1.

3. A case including a base, A first fixed terminal, which includes a first fixed contact and is supported on the base, A second fixed contact is included, which is positioned away from the first fixed terminal and is supported by the base, A movable contact piece including a first movable contact facing the first fixed contact and a second movable contact facing the second fixed contact, A drive device that moves the movable contact piece in a movement direction including a first direction in which the first movable contact approaches the first fixed contact and a second direction in which the first movable contact moves away from the first fixed contact, Equipped with, The first fixed terminal is, A first contact support portion extends parallel to the third direction from the second movable contact toward the first movable contact, and the first fixed contact is arranged therein. A first external connection portion extends from the inside to the outside of the case in a fourth direction perpendicular to the first and third directions, is positioned in the second direction relative to the movable contact piece, and overlaps with the first fixed contact in the direction of movement of the movable contact piece, Inside the case, a first extension portion extends from the first external connection portion in the third direction, A first connecting portion that connects the first contact support portion and the first extension portion, Includes, The first connecting portion is located outside the base, Electromagnetic relay.

4. The base includes a first support wall that supports the first contact support portion from the first direction. An electromagnetic relay according to any one of claims 1 to 3.

5. The base includes a second support wall that supports the first external connection portion and the first extension portion from the second direction. An electromagnetic relay according to any one of claims 1 to 4.

6. The first extension is separated from the space in which the first fixed contact is housed. An electromagnetic relay according to any one of claims 1 to 5.

7. The second fixed terminal is, A second contact support portion extending parallel to the third direction, on which the second fixed contact is located, A second external connection portion extends from the inside to the outside of the case in the fourth direction, is positioned in the second direction relative to the movable contact piece, and overlaps with the second fixed contact in the direction of movement of the movable contact piece, Inside the case, a second extension extends from the second external connection portion in a fifth direction opposite to the third direction, A second connecting portion that connects the second contact support portion and the second extension portion, including, An electromagnetic relay according to any one of claims 1 to 6.

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