Electromagnetic relay

Abstract

An electromagnetic relay (1) is provided with a transmission line base (3), a movable contact piece (6A), a coil block (41), and a movable block (42). The transmission line base includes a first conductor layer (11) and a second conductor layer (12). The first conductor layer includes a first transmission line (24A) and a second transmission line (25A). The movable contact piece includes a joint portion (32A) joined to the first transmission line. The movable contact piece is movable between a connection position for connecting the first transmission line and the second transmission line, and a disconnection position for disconnecting the first transmission line and the second transmission line. The coil block includes a coil (43). The movable block is operated by the electromagnetic force of the coil to move the movable contact piece between the connection position and the disconnection position. The first transmission line includes a wide portion (242A). The wide portion has a width larger than the width of the joint portion of the movable contact piece, and the joint portion is joined thereto. The second conductor layer includes an opening portion (121) that is opened facing the wide portion.

Description

electromagnetic relay

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

[0002] Electromagnetic relays are used to switch high-frequency signals. For example, the electromagnetic relay disclosed in Patent Document 1 includes a movable contact piece including a pair of movable contacts, a first transmission line including a first fixed contact, a second transmission line including a second fixed contact, a movable block, and an electromagnet block. The electromagnet block generates an electromagnetic force that operates the movable block. The movable block presses the movable contact piece to bring the pair of movable contacts into contact with the first and second fixed contacts. This connects the first and second transmission lines to each other.

[0003] JP 2011-96410 A

[0004] In the electromagnetic relay described above, for example, one end of the movable contact piece may be a fixed end joined to the first transmission line, and the other end of the movable contact piece may be a free end that contacts the second transmission line in response to the movement of the movable block. In this case, when joining the movable contact piece to the first transmission line, the joining position of the movable contact piece relative to the first transmission line may extend beyond the width of the first transmission line. If the joining position of the movable contact piece extends beyond the width of the first transmission line, the width of the first transmission line at the joint increases, resulting in a lower characteristic impedance and poor high-frequency characteristics.

[0005] An object of the present invention is to provide an electromagnetic relay that can suppress deterioration of the high frequency characteristics of the transmission line to which the movable contact piece is joined.

[0006] An electromagnetic relay according to one aspect of the present invention includes a transmission line base, a movable contact piece, a coil block, and a movable block. The transmission line base includes a first conductor layer and a second conductor layer. The first conductor layer includes a first transmission line and a second transmission line. The second conductor layer is disposed below the first conductor layer. The movable contact piece is disposed above the first conductor layer. The movable contact piece includes a joint portion joined to the first transmission line. The movable contact piece is movable between a connection position connecting the first transmission line and the second transmission line and a disconnection position disconnecting the first transmission line and the second transmission line. The coil block includes a coil. The movable block is actuated by electromagnetic force of the coil to move the movable contact piece between the connection position and the disconnection position. The first transmission line includes a wide portion. The wide portion has a width greater than the width of the joint portion of the movable contact piece, and the joint portion is connected to the wide portion. The second conductor layer includes an opening facing the wide portion.

[0007] In the electromagnetic relay according to this aspect, the joint portion of the movable contact piece is joined to a wide portion of the first transmission line, which is wider than the width of the joint portion of the movable contact piece. Therefore, when joining the movable contact piece to the first transmission line, the joint position of the movable contact piece relative to the first transmission line can be prevented from extending beyond the width of the first transmission line. The characteristic impedance is determined by the inductance value of the first transmission line and the capacitance value between the first transmission line and the second conductor layer. The opening in the second conductor layer faces the wide portion, so the opening can reduce the capacitance between the first transmission line and the second conductor layer at the joint portion. For example, by setting the size of the opening in the first transmission line so that the characteristic impedance of the wide portion and the remaining portion are approximately the same, the high-frequency characteristics of the first transmission line can be stabilized. As a result, deterioration of the high-frequency characteristics of the first transmission line to which the movable contact piece is joined can be prevented.

[0008] The opening of the second conductor layer may have a width smaller than the width of the wide portion of the first transmission line, in which case the characteristic impedance of the wide portion of the first transmission line can be made similar to the characteristic impedance of the portion other than the wide portion, thereby stabilizing the high-frequency characteristics of the first transmission line.

[0009] The opening of the second conductor layer may have a width smaller than that of the joint of the movable contact piece. In this case, the characteristic impedance of the wide portion can be made similar to that of the portion other than the wide portion, thereby stabilizing the high-frequency characteristics of the first transmission line.

[0010] The transmission line base may further include a dielectric layer disposed between the first conductor layer and the second conductor layer. The dielectric layer may have a cavity shape between the opening of the second conductor layer and the joint portion of the movable contact piece. In this case, the characteristic impedance of the wide portion can be adjusted by using the dielectric layer.

[0011] The opening of the second conductor layer may include a corner having an R-shaped or C-shaped corner, in which case reflection can be suppressed in the first transmission line, thereby stabilizing the high-frequency characteristics of the first transmission line.

[0012] The wide portion of the first transmission line may include a corner having an R-shaped or C-shaped surface. In this case, reflection of the first transmission line can be suppressed, and therefore, high frequency characteristics of the first transmission line can be stabilized.

[0013] According to the present invention, it is possible to provide an electromagnetic relay that can suppress deterioration of the high frequency characteristics of the transmission line to which the movable contact piece is joined.

[0014] 1 is a perspective view of an electromagnetic relay; 2 is a perspective view of an electromagnetic relay; 3 is an exploded perspective view of an electromagnetic relay; 4 is a perspective view of a transmission line base; 5 is a top view of the transmission line base; 6 is a perspective view of the base assembly and the stand seen from below; 7 is a perspective view of the base assembly seen from below; 8 is an exploded perspective view of the base assembly; 9 is a cross-sectional view of the electromagnetic relay in an open state; 10 is a perspective view of a movable block; 11 is a cross-sectional view of the electromagnetic relay in a closed state; 12 is a partial cross-sectional view of the electromagnetic relay passing through the first wide portion and the second wide portion; 13 is a view from above of the periphery of the first joint and the second joint; 14 is a partial cross-sectional view of the electromagnetic relay passing through the first wide portion and the second wide portion according to a modified example.

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An electromagnetic relay according to an embodiment will now be described with reference to the drawings. The electromagnetic relay according to the present embodiment is used to switch between a high frequency RF signal and a low frequency DC signal.

[0016] 1 and 2 are perspective views of an electromagnetic relay 1 according to an embodiment. As shown in Fig. 1 and 2, the electromagnetic relay 1 includes a case 2, a transmission line base 3, a base assembly 4, and a stand 5. Note that the case 2 is omitted in Fig. 2. In the following description, the direction in which the base assembly 4 and the stand 5 are arranged relative to the transmission line base 3 is defined as "upward," and the opposite direction is defined as "downward."

[0017] As shown in Fig. 1, the case 2 is attached to the transmission line base 3. The case 2 covers the upper surface of the transmission line base 3, the base assembly 4, and the stand 5. Fig. 3 is an exploded perspective view of the electromagnetic relay 1. As shown in Fig. 3, the electromagnetic relay 1 includes a first movable contact piece 6A, a second movable contact piece 6B, and a shield plate 7. The first movable contact piece 6A, the second movable contact piece 6B, and the shield plate 7 are arranged on the transmission line base 3.

[0018] FIG. 4 is a perspective view of the transmission line base 3. Note that the shield plate 7 is omitted in FIG. 4. The transmission line base 3 is a printed circuit board. However, the transmission line base 3 may also be a ceramic substrate, a resin molded product, a metal molded product, an FPC (flexible printed circuit board), or an MID (molded circuit component). As shown in FIG. 4, the transmission line base 3 includes first to fourth conductor layers 11-14 and first to third dielectric layers 15-17. The first to fourth conductor layers 11-14 are made of an electrically conductive material such as copper. The first to third dielectric layers 15-17 are made of a dielectric material. The first to fourth conductor layers 11-14 and the first to third dielectric layers 15-17 are alternately stacked.

[0019] The first conductor layer 11 is provided on the upper surface of the transmission line base 3. Fig. 5 is a top view of the transmission line base 3. Note that the shield plate 7 and the movable contact pieces 6A and 6B are omitted in Fig. 5. As shown in Figs. 4 and 5, the first conductor layer 11 is provided with a first RF line 21A, a second RF line 21B, a first DC line 22A, a second DC line 22B, and a ground line 23.

[0020] The first RF line 21A and the second RF line 21B are transmission lines for transmitting RF signals. The first RF line 21A and the second RF line 21B are arranged side by side in a predetermined direction. Hereinafter, the direction in which the first RF line 21A and the second RF line 21B are arranged side by side (the up-down direction on the paper surface of FIG. 5 ) is referred to as the width direction. The first RF line 21A and the second RF line 21B are spaced apart in the width direction. The first RF line 21A and the second RF line 21B extend in a predetermined direction. Hereinafter, the direction in which the first RF line 21A and the second RF line 21B extend (the left-right direction on the paper surface of FIG. 5 ) is referred to as the longitudinal direction.

[0021] The first RF line 21A includes a first transmission line 24A and a second transmission line 25A. The first transmission line 24A and the second transmission line 25A are arranged apart from each other. The first transmission line 24A and the second transmission line 25A are electrically isolated from each other. The first transmission line 24A is connected to a first input terminal 26A. The second transmission line 25A is connected to a first RF terminal 27A. The first input terminal 26A and the first RF terminal 27A are each a through-hole terminal provided on an end surface of the transmission line base 3.

[0022] The second RF line 21B is arranged side by side with the first RF line 21A in a predetermined direction. Hereinafter, the direction in which the first RF line 21A and the second RF line 21B are arranged side by side (the up-down direction on the paper surface of FIG. 5) will be referred to as the width direction. The second RF line 21B is separated from the first RF line 21A in the width direction.

[0023] The second RF line 21B includes a third transmission line 24B and a fourth transmission line 25B. The third transmission line 24B and the fourth transmission line 25B are arranged apart from each other. The third transmission line 24B and the fourth transmission line 25B are electrically isolated from each other. The third transmission line 24B is connected to a second input terminal 26B. The fourth transmission line 25B is connected to a second RF terminal 27B. The second input terminal 26B and the second RF terminal 27B are each a through-hole terminal provided on an end surface of the transmission line base 3.

[0024] The first DC line 22A and the second DC line 22B are transmission lines for transmitting DC signals. The first DC line 22A is connected to the first transmission line 24A and the ground line 23. A first inductor 28A and a first capacitor 29A are disposed on the first DC line 22A. Note that in the drawings, only a portion of the first inductor 28A is denoted by the reference numeral 28A, and the reference numerals for the remaining first inductors 28A are omitted.

[0025] The first DC line 22A is connected to a first DC terminal 30A between the first inductor 28A and the first capacitor 29A. The first DC terminal 30A is a through-hole terminal provided on an end surface of the transmission line base 3. The first DC line 22A, the first inductor 28A, and the first capacitor 29A function as a low-pass filter that passes DC signals but blocks RF signals. The first inductor 28A and the first capacitor 29A are configured to block high-frequency signals, for example, of 1 kHz or higher.

[0026] The second DC line 22B is connected to the third transmission line 24B and the ground line 23. A second inductor 28B and a second capacitor 29B are arranged on the second DC line 22B. Note that in the drawing, only a portion of the second inductor 28B is denoted by the reference numeral 28B, and the reference numerals for the remaining second inductors 28B are omitted.

[0027] The second DC line 22B is connected to a second DC terminal 30B between the second inductor 28B and the second capacitor 29B. The second DC terminal 30B is a through-hole terminal provided on an end surface of the transmission line base 3. The second DC line 22B, the second inductor 28B, and the second capacitor 29B function as a low-pass filter that passes DC signals but blocks RF signals. The second inductor 28B and the second capacitor 29B are set to block high-frequency signals, for example, of 1 kHz or higher.

[0028] The second to fourth conductor layers 12-14 are ground layers. The second conductor layer 12 is disposed below the first conductor layer 11. The second conductor layer 12 is stacked on the first conductor layer 11 with a first dielectric layer 15 interposed therebetween. The third conductor layer 13 is stacked on the second conductor layer 12 with a second dielectric layer 16 interposed therebetween. The fourth conductor layer 14 is stacked on the third conductor layer 13 with a third dielectric layer 17 interposed therebetween.

[0029] A plurality of through-hole terminals 31 are provided on an end face of the transmission line base 3. In the drawings, only some of the through-hole terminals 31 are labeled with the reference numeral 31, and the reference numerals of the other through-hole terminals 31 are omitted. The through-hole terminals 31 connect the above-described ground line 23 to the second to fourth conductor layers 12-14.

[0030] The first dielectric layer 15 is disposed between the first conductor layer 11 and the second conductor layer 12. The first dielectric layer 15 is disposed in contact with the lower surface of the first conductor layer 11 and the upper surface of the second conductor layer 12. The second dielectric layer 16 is disposed between the second conductor layer 12 and the third conductor layer 13. The second dielectric layer 16 is disposed in contact with the lower surface of the second conductor layer 12 and the upper surface of the third conductor layer 13. The third dielectric layer 17 is disposed between the third conductor layer 13 and the fourth conductor layer 14. The third dielectric layer 17 is disposed in contact with the lower surface of the third conductor layer 13 and the upper surface of the fourth conductor layer 14.

[0031] 4, the first movable contact piece 6A and the second movable contact piece 6B are disposed on the transmission line base 3. The first movable contact piece 6A and the second movable contact piece 6B are disposed above the first conductor layer 11. The first movable contact piece 6A and the second movable contact piece 6B extend in the longitudinal direction. The first movable contact piece 6A is disposed above the first RF line 21A.

[0032] The first movable contact piece 6A includes a first joint portion 32A, a first contact portion 33A, and a first intermediate portion 34A. The first joint portion 32A is a fixed end. The first joint portion 32A is joined to the first transmission line 24A. The first joint portion 32A is joined to the first transmission line 24A by joining means such as welding or soldering. The first contact portion 33A is a free end. The first contact portion 33A is disposed above the second transmission line 25A. The first intermediate portion 34A is located between the first joint portion 32A and the first contact portion 33A. The first intermediate portion 34A extends in a substantially linear manner parallel to the first transmission line 24A and the second transmission line 25A.

[0033] As described below, the first movable contact piece 6A is movable between a connection position and a disconnection position. When the first movable contact piece 6A is in the connection position, the first contact portion 33A contacts the second transmission line 25A. This causes the first movable contact piece 6A to connect the first transmission line 24A and the second transmission line 25A. When the first movable contact piece 6A is in the disconnection position, the first contact portion 33A separates from the second transmission line 25A. This causes the first movable contact piece 6A to disconnect the first transmission line 24A and the second transmission line 25A.

[0034] The second movable contact piece 6B is disposed above the second RF line 21B. The second movable contact piece 6B includes a second joint portion 32B, a second contact portion 33B, and a second intermediate portion 34B. The second joint portion 32B is joined to the third transmission line 24B by joining means such as welding or soldering. The second contact portion 33B is disposed above the fourth transmission line 25B. The second intermediate portion 34B is located between the second joint portion 32B and the second contact portion 33B. The second intermediate portion 34B extends in a substantially linear manner parallel to the third transmission line 24B and the fourth transmission line 25B.

[0035] Like the first movable contact piece 6A, the second movable contact piece 6B is movable between a connected position and a disconnected position. When the second movable contact piece 6B is in the connected position, the second contact portion 33B contacts the fourth transmission line 25B. This causes the second movable contact piece 6B to connect the third transmission line 24B and the fourth transmission line 25B. When the second movable contact piece 6B is in the disconnected position, the second contact portion 33B separates from the fourth transmission line 25B. This causes the second movable contact piece 6B to disconnect the third transmission line 24B and the fourth transmission line 25B.

[0036] The shield plate 7 is disposed on the transmission line base 3. The shield plate 7 is made of a conductive material. The shield plate 7 is disposed above the first contact portion 33A and the second contact portion 33B. The shield plate 7 is connected to the ground line 23. The shield plate 7 improves the isolation characteristics between the first RF line 21A and the second RF line 21B.

[0037] Fig. 6 is a perspective view of the base assembly 4 and the stand 5 as viewed from below. Fig. 7 is a perspective view of the base assembly 4 as viewed from below. Fig. 8 is an exploded perspective view of the base assembly 4. Fig. 9 is a cross-sectional view of the electromagnetic relay 1. As shown in Figs. 6 to 9, the base assembly 4 includes a coil base 40, a coil block 41, and a movable block 42.

[0038] The coil block 41 includes a coil 43, a spool 44, and an iron core 45. The coil 43 is wound around the spool 44. The iron core 45 is disposed within the coil 43. The iron core 45 includes an intermediate portion 46, a first attraction portion 47, and a second attraction portion 48. The intermediate portion 46 is disposed within the coil 43 and extends in the axial direction of the coil 43. The first attraction portion 47 protrudes from the coil 43 in the axial direction of the coil 43. The first attraction portion 47 is disposed facing downward. The second attraction portion 48 protrudes from the coil 43 in the opposite direction to the first attraction portion 47 in the axial direction of the coil 43. The second attraction portion 48 is disposed facing downward.

[0039] The movable block 42 is operated by the electromagnetic force of the coil 43 to move the first movable contact piece 6A and the second movable contact piece 6B between the connection position and the disconnection position. Fig. 10 is a perspective view of the movable block 42. As shown in Fig. 10, the movable block 42 includes an iron piece 50, a first hinge spring 51, a second hinge spring 52, a permanent magnet 53, a card 54, and a movable insulating base 55.

[0040] The iron piece 50 is supported by a movable insulating base 55. The iron piece 50 includes a first end 56 and a second end 57. The first end 56 protrudes from the movable insulating base 55 in the axial direction of the coil 43. The first end 56 is disposed below the first attraction portion 47 of the iron core 45 and faces the first attraction portion 47. The second end 57 protrudes from the movable insulating base 55 in the opposite direction to the first end 56 in the axial direction of the coil 43. The second end 57 is disposed below the second attraction portion 48 of the iron core 45 and faces the second attraction portion 48.

[0041] The first hinge spring 51 is supported by the movable insulating base 55. The first hinge spring 51 protrudes from the movable insulating base 55 toward one side of the movable insulating base 55. The second hinge spring 52 is supported by the movable insulating base 55. The second hinge spring 52 protrudes from the movable insulating base 55 toward the other side of the movable insulating base 55. The permanent magnet 53 is attached to the upper surface of the movable insulating base 55.

[0042] The card 54 is supported by the movable insulating base 55. The card 54 protrudes downward from the movable insulating base 55. The card 54 is disposed above the first movable contact piece 6A and the second movable contact piece 6B. Specifically, the card 54 is disposed above the first intermediate portion 34A of the first movable contact piece 6A and the second intermediate portion 34B of the second movable contact piece 6B. The card 54 is connected to the underside of the first end portion 56 of the iron piece 50. The card 54 protrudes downward from the underside of the first end portion 56.

[0043] The movable insulating base 55 is supported so as to be able to swing relative to the coil base 40. As shown in FIG. 8 , the coil base 40 includes support protrusions 58 and 59. As shown in FIG. 10 , the movable insulating base 55 includes support holes 60 and 61. The support protrusions 58 and 59 are disposed in the support holes 60 and 61 and support the movable insulating base 55 so as to be able to swing. Also, as shown in FIG. 8 , the coil base 40 includes a first support recess 62 and a second support recess 63. The first hinge spring 51 is disposed in the first support recess 62. The first hinge spring 51 is connected to the coil base 40 at the first support recess 62. The second hinge spring 52 is disposed in the second support recess 63. The second hinge spring 52 is connected to the coil base 40 at the second support recess 63. The movable insulating base 55 is supported by the coil base 40 so as to be swingable around the first hinge spring 51 and the second hinge spring 52 .

[0044] The stand 5 is disposed above the transmission line base 3 and supports the base assembly 4. More specifically, the stand 5 supports the coil base 40. The coil block 41 is supported by the stand 5 via the coil base 40. The movable block 42 is supported by the stand 5 via the coil base 40. The stand 5 includes a frame 70 and a plurality of legs 71-74. As shown in FIG. 6 , the frame 70 has an opening 75 in its center. The movable block 42 is disposed within the opening 75 of the frame 70. The card 54 extends downward through the opening 75.

[0045] A plurality of legs 71-74 protrude downward from the frame 70. The plurality of legs 71-74 each include a flat bottom surface 76-79. Specifically, the plurality of legs 71-74 includes a first leg 71, a second leg 72, a third leg 73, and a fourth leg 74. The first to fourth legs 71-74 are respectively disposed at corners of the frame 70.

[0046] As shown in FIGS. 12 and 13 , the first transmission line 24A includes a first extending portion 241A and a first wide portion 242A. The first extending portion 241A extends in the longitudinal direction. The width of the first extending portion 241A is approximately the same as the width of the first movable contact piece 6A. The first extending portion 241A overlaps the second conductor layer 12 when viewed in the vertical direction. The first wide portion 242A extends in the longitudinal direction from the first extending portion 241A. The first wide portion 242A has a width greater than that of the first extending portion 241A. The first wide portion 242A protrudes in the width direction more than the first extending portion 241A. In the width direction, the dimension of the first wide portion 242A is greater than the dimension of the first extending portion 241A. The first wide portion 242A has a substantially rectangular shape when viewed in the vertical direction. The first wide portion 242A includes corners 243A having a rounded or chamfered shape. In this embodiment, all four corners of the first wide portion 242A have a chamfered shape.

[0047] The first wide portion 242A overlaps with the first joint portion 32A of the first movable contact piece 6A when viewed from the top-bottom direction. The first joint portion 32A is joined to the first wide portion 242A. The first wide portion 242A has a width greater than that of the first joint portion 32A. The first joint portion 32A is disposed within the width of the first wide portion 242A. The width of the first joint portion 32A is approximately the same as the width of the first extending portion 241A. The first joint portion 32A does not overlap with the first extending portion 241A when viewed from the top-bottom direction.

[0048] The third transmission line 24B includes a second extending portion 241B and a second wide portion 242B. The second extending portion 241B extends in the longitudinal direction. The width of the second extending portion 241B is approximately the same as the width of the second movable contact piece 6B. The second extending portion 241B overlaps with the second conductor layer 12 when viewed in the vertical direction. The second wide portion 242B extends in the longitudinal direction from the second extending portion 241B. The second wide portion 242B protrudes in the width direction more than the second extending portion 241B. In other words, the second wide portion 242B has a width greater than that of the second extending portion 241B. The second wide portion 242B is substantially rectangular when viewed in the vertical direction. The second wide portion 242B includes corners 243B having an R-shaped or C-shaped surface.

[0049] The second wide portion 242B overlaps with the second joint portion 32B of the second movable contact piece 6B when viewed from the top-bottom direction. The second joint portion 32B is joined to the second wide portion 242B. The second wide portion 242B has a width greater than that of the second joint portion 32B. The second joint portion 32B is disposed within the width of the second wide portion 242B. The width of the second joint portion 32B is approximately the same as the width of the second extending portion 241B. The second joint portion 32B does not overlap with the second extending portion 241B when viewed from the top-bottom direction.

[0050] The second conductor layer 12 includes a first opening 121 and a second opening 122. The first opening 121 is open facing the first wide portion 242A. The first opening 121 has a substantially rectangular shape when viewed from the top and bottom. The first opening 121 includes corners 121a having an R-shaped or C-shaped configuration. In this embodiment, all four corners of the first opening 121 have a C-shaped configuration.

[0051] The first opening 121 overlaps with the first wide portion 242A and the first joint portion 32A when viewed from the top-bottom direction. The first opening 121 does not overlap with the first extending portion 241A when viewed from the top-bottom direction. The first opening 121 has a width smaller than that of the first wide portion 242A of the first transmission line 24A. The first opening 121 has a width smaller than that of the first joint portion 32A of the first movable contact piece 6A. The first opening 121 is positioned within the width of the first wide portion 242A when viewed from the top-bottom direction. The first opening 121 is positioned within the width of the first joint portion 32A when viewed from the top-bottom direction.

[0052] The second opening 122 is open and faces the second wide portion 242B. The second opening 122 has a substantially rectangular shape when viewed from the top and bottom. The second opening 122 includes corners 122a that are rounded or chamfered.

[0053] The second opening 122 overlaps with the second wide portion 242B and the second joint portion 32B when viewed from the top-bottom direction. The second opening 122 does not overlap with the second extending portion 241B when viewed from the top-bottom direction. The second opening 122 has a width smaller than that of the second wide portion 242B of the third transmission line 24B. The second opening 122 has a width smaller than that of the second joint portion 32B of the second movable contact piece 6B. The second opening 122 is positioned within the width of the second wide portion 242B when viewed from the top-bottom direction. The second opening 122 is positioned within the width of the second joint portion 32B when viewed from the top-bottom direction.

[0054] The third conductor layer 13 has the same shape as the second conductor layer 12. The third conductor layer 13 includes a third opening 131 and a fourth opening 132. The third opening 131 overlaps with the first opening 121 when viewed from the top-bottom direction. The fourth opening 132 overlaps with the second opening 122 when viewed from the top-bottom direction.

[0055] Next, the operation of the electromagnetic relay 1 will be described. FIG. 9 shows the electromagnetic relay 1 in an open state. When no current flows through the coil 43, the coil 43 is not excited, and the iron piece 50 is not attracted to the iron core 45. Due to the magnetic force of the permanent magnet 53, the first end 56 of the iron piece 50 is attracted to and contacts the first attraction portion 47 of the iron core 45. Therefore, the card 54 is separated from the first movable contact piece 6A and the second movable contact piece 6B, and the first movable contact piece 6A and the second movable contact piece 6B are each in the disconnected position. Therefore, in the first RF line 21A, the first transmission line 24A and the second transmission line 25A are disconnected from each other. In addition, in the second RF line 21B, the third transmission line 24B and the fourth transmission line 25B are disconnected from each other. In the breaking position, the first movable contact piece 6A and the second movable contact piece 6B come into contact with the insulating layer 20 arranged on the lower surface of the shield plate 7.

[0056] When current flows through the coil 43, the electromagnetic relay 1 is in the closed state shown in FIG. 11 . When the electromagnetic relay 1 is in the closed state, the electromagnetic force of the coil 43 causes the second end 57 of the iron piece 50 to be attracted to the second attraction portion 48 of the iron core 45 and rise. This causes the iron piece 50 to swing, and the first end 56 to descend. The card 54 descends together with the first end 56 and presses the first movable contact piece 6A and the second movable contact piece 6B, thereby moving the first movable contact piece 6A and the second movable contact piece 6B to their respective connected positions. This connects the first transmission line 24A and the second transmission line 25A to each other in the first RF line 21A. Furthermore, the third transmission line 24B and the fourth transmission line 25B to each other in the second RF line 21B.

[0057] When the current to the coil 43 is interrupted, the spring reaction forces of the first movable contact piece 6A, the second movable contact piece 6B, the first hinge spring 51, and the second hinge spring 52, as well as the magnetic force of the permanent magnet 53, rotate the iron piece 50 in the opposite direction, causing the second end 57 to descend and separate from the second attraction portion 48, and the first end 56 to rise. The card 54 rises together with the first end 56 and separates from the first movable contact piece 6A and the second movable contact piece 6B. As a result, the first movable contact piece 6A and the second movable contact piece 6B return to their respective disconnected positions due to the elastic forces of the first movable contact piece 6A and the second movable contact piece 6B. As a result, the first transmission line 24A and the second transmission line 25A are disconnected from each other in the first RF line 21A. In addition, in the second RF line 21B, the third transmission line 24B and the fourth transmission line 25B are isolated from each other.

[0058] For example, when an RF signal is input to the first input terminal 26A and the second input terminal 26B of the electromagnetic relay 1, the electromagnetic relay 1 is closed. In this case, the first transmission line 24A and the second transmission line 25A are connected to each other, and the third transmission line 24B and the fourth transmission line 25B are connected to each other. Therefore, the RF signal passes from the first input terminal 26A through the first RF line 21A and is output from the first RF terminal 27A. The RF signal passes from the second input terminal 26B through the second RF line 21B and is output from the second RF terminal 27B. Meanwhile, the RF signal is cut by the first DC line 22A and the second DC line 22B, respectively, and is therefore prevented from being output from the first DC terminal 30A and the second DC terminal 30B.

[0059] When a DC signal is input to the first input terminal 26A and the second input terminal 26B of the electromagnetic relay 1, the electromagnetic relay 1 is in an open state. In this state, the first transmission line 24A and the second transmission line 25A are disconnected from each other, and the third transmission line 24B and the fourth transmission line 25B are disconnected from each other. Therefore, the DC signal is output from the first input terminal 26A through the first DC line 22A and the first DC terminal 30A without passing through the first RF line 21A. The DC signal is output from the second input terminal 26B through the second DC line 22B and the second DC terminal 30B without passing through the second RF line 21B. This prevents the DC signal from flowing through the first movable contact 6A and the second movable contact 6B.

[0060] In the above-described electromagnetic relay 1, the first joint portion 32A of the first movable contact piece 6A is joined to the first wide portion 242A of the first transmission line 24A, which is wider than the width of the first joint portion 32A of the first movable contact piece 6A. Therefore, when joining the first movable contact piece 6A to the first transmission line 24A, it is possible to prevent the joining position of the first movable contact piece 6A to the first transmission line 24A from extending beyond the width of the first transmission line 24A.

[0061] Here, the characteristic impedance is determined by the inductance value of the first transmission line 24A and the capacitance value between the first transmission line 24A and the second conductor layer 12. The first opening 121 of the second conductor layer 12 faces the first wide portion 242A, so the first opening 121 can reduce the capacitance between the first transmission line 24A and the second conductor layer 12 at the joint. In this embodiment, the size of the first opening 121 of the first transmission line 24A is set so that the characteristic impedance of the first wide portion 242A is approximately equal to the characteristic impedance of the first extension portion 241A. This stabilizes the high-frequency characteristics of the first transmission line 24A. As a result, deterioration of the high-frequency characteristics of the first transmission line 24A to which the first movable contact piece 6A is joined can be suppressed. Similarly, the second opening 122 can stabilize the high-frequency characteristics of the third transmission line 24B.

[0062] 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 gist of the invention.

[0063] The configuration of the transmission line base 3 is not limited to that of the above embodiment and may be modified. The configuration of the transmission lines of the transmission line base 3 is not limited to that of the above embodiment and may be modified. For example, the second RF line 21B and the second DC line 22B may be omitted. The configuration of the terminals of the transmission line base 3 is not limited to that of the above embodiment and may be modified. For example, the second input terminal 26B, the second RF terminal 27B, and the second DC terminal 30B may be omitted. A signal may flow in the opposite direction to that of the above embodiment. The configuration of the base assembly 4 is not limited to that of the above embodiment and may be modified. For example, the stand 5 is not limited to being separate from the coil base 40 and may be integrated with it.

[0064] As shown in FIG. 14 , the first dielectric layer 15 may have a cavity shape between the first opening 121 of the second conductor layer 12 and the first joint portion 32A of the first movable contact piece 6A. The first dielectric layer 15 may have a shape recessed from bottom to top between the first opening 121 and the first joint portion 32A of the first movable contact piece 6A. Alternatively, the first dielectric layer 15 may have a shape recessed from top to bottom between the first opening 121 and the first joint portion 32A of the first movable contact piece 6A. Alternatively, the characteristic impedance of the first wide portion 242A may be adjusted by the size of the first opening 121 and the shape of the first dielectric layer 15. The first dielectric layer 15 may be omitted between the first opening 121 of the second conductor layer 12 and the first joint portion 32A of the first movable contact piece 6A. The first dielectric layer 15 may include an opening that opens in the vertical direction between the first opening 121 of the second conductor layer 12 and the first joint portion 32A of the first movable contact piece 6A. The first dielectric layer 15 may have a cavity shape between the second opening 122 of the second conductor layer 12 and the second joint portion 32B of the second movable contact piece 6B.

[0065] 3: Transmission line base, 6A: First movable contact piece, 11: First conductor layer, 12: Second conductor layer, 24A: First transmission line, 25A: Second transmission line, 41: Coil block, 42: Movable block, 43: Coil, 121: First opening, 242A: First wide portion

Claims

1. An electromagnetic relay comprising: a transmission line base including a first conductor layer including a first transmission line and a second transmission line, and a second conductor layer arranged below the first conductor layer; a movable contact piece including a junction joined to the first transmission line, arranged above the first conductor layer, and movable between a connection position connecting the first transmission line and the second transmission line and a disconnection position disconnecting the first transmission line and the second transmission line; a coil block including a coil; and a movable block operated by electromagnetic force of the coil to move the movable contact piece between the connection position and the disconnection position, wherein the first transmission line has a width greater than a width of the junction of the movable contact piece, and includes a wide portion to which the junction of the movable contact piece is joined, and the second conductor layer includes an opening facing the wide portion.

2. The electromagnetic relay according to claim 1, wherein the opening in the second conductor layer has a width smaller than a width of the wide portion of the first transmission line.

3. The electromagnetic relay according to claim 1, wherein the opening in the second conductor layer has a width smaller than that of the joint of the movable contact piece.

4. The electromagnetic relay according to claim 1, wherein the transmission line base further includes a dielectric layer disposed between the first conductor layer and the second conductor layer, and the dielectric layer has a cavity shape between the opening of the second conductor layer and the joint of the movable contact piece.

5. The electromagnetic relay according to claim 1, wherein the opening in the second conductor layer includes a corner having an R-shaped or C-shaped surface.

6. The electromagnetic relay according to claim 1, wherein the wide portion of the first transmission line includes a corner having an R-shaped or C-shaped surface.

Images