Electromagnetic device

Abstract

An electromagnet device includes a coil, a pulley, an iron core, a yoke, a movable iron piece, an auxiliary yoke, and a permanent magnet. The coil is wound around the pulley. The iron core is located inside the pulley. The yoke includes a base portion and an extension portion. The base portion extends in a direction intersecting an axial direction of the iron core and is fixed to one end of the iron core. The extension portion is connected to the base portion and arranged laterally relative to the coil. The movable iron piece is rotatably supported by the extension portion of the yoke. The auxiliary yoke is connected to an outer side of the base portion of the yoke. The permanent magnet is positioned on an extension line of the axis of the iron core and is located between the base portion of the yoke and the auxiliary yoke.

Description

AREA

[0001] The claimed invention relates to an electromagnet device. STATE OF THE ART

[0002] Conventionally, a self-holding electromagnet device with a permanent magnet has been disclosed (see Patent Document 1). The permanent magnet is positioned on the extension line of the axis of an iron core and held between an auxiliary yoke and a yoke. The permanent magnet increases the attractive force of the iron core acting on the movable iron piece. PRIOR ART DOCUMENT PATENT DOCUMENT

[0003] [Patent Document 1] Japanese Patent Publication No. 2014-44838 SUMMARYTechnical task

[0004] In the electromagnet device disclosed in Patent Document 1, an auxiliary yoke is located inside the yoke, and the auxiliary yoke is joined to the yoke by laser welding or bonding, with a magnet sandwiched between the auxiliary yoke and the yoke. Accordingly, assembling the electromagnet device is not easy.

[0005] An object of the claimed invention is to improve the assemblability of an electromagnet device. Solution to the task

[0006] An electromagnet device according to one aspect of the claimed invention includes a coil, a pulley, an iron core, a yoke, a movable iron piece, an auxiliary yoke, and a permanent magnet. The coil is wound around the pulley. The iron core is located inside the pulley. The yoke includes a base portion and an extension portion. The base portion extends in a direction intersecting an axial direction of the iron core and is fixed to one end of the iron core. The extension portion is connected to the base portion and arranged laterally relative to the coil. The movable iron piece is rotatably supported by the extension portion of the yoke. The auxiliary yoke is connected to the base portion of the yoke on an outer side of the base portion.The permanent magnet is positioned on an extension line of the axis of the iron core and is located between the base section of the yoke and the auxiliary yoke.

[0007] In this electromagnet device, the auxiliary yoke is connected to the base portion of the yoke on the outside of the base portion, and the permanent magnet is located between the base portion of the yoke and the auxiliary yoke. That is, the auxiliary yoke and the permanent magnet are arranged on the outside of the yoke. With this configuration, the permanent magnet and the auxiliary yoke can be assembled on the outside of the yoke, thereby improving the assemblability of the electromagnet device. In addition, the electromagnet device according to the claimed invention can be easily assembled, for example, by attaching a permanent magnet and an auxiliary yoke to a conventional articulated single-stable electromagnet device from the outside. Furthermore, with the conventional articulated single-stable electromagnet device, conventional components can be used except for the permanent magnet and the auxiliary yoke.

[0008] The base portion of the yoke may include a first contact portion configured to contact the permanent magnet, a second contact portion configured to contact the auxiliary yoke, and a reduced cross-sectional area portion located between the first and second contact portions. The reduced cross-sectional area portion may be spaced apart from the auxiliary yoke in the axial direction and may have a smaller cross-sectional area than a cross-sectional area of ​​the second contact portion. In this case, the magnetic flux of the permanent magnet flows more easily through the magnetic circuit passing through the movable iron piece, thereby increasing the holding force for retaining the movable iron piece in the operating position.

[0009] The section with reduced cross-sectional area may include a through hole that extends the base section in the axial direction. In this case, too, the magnetic flux of the permanent magnet flows more easily through the magnetic circuit passing through the movable iron piece, thereby increasing the holding force for retaining the movable iron piece in the operating position.

[0010] The base portion may further include a caulking hole. The through hole of the reduced-cross-sectional area portion may have a width dimension larger than the inner diameter dimension of the caulking hole. Also in this case, the magnetic flux of the permanent magnet flows more easily through the magnetic circuit passing through the movable iron piece, thereby increasing the holding force for retaining the movable iron piece in the operating position.

[0011] The section with reduced cross-sectional area may include a narrowed section. The narrowed section may have a width dimension smaller than the width dimension of the permanent magnet. In this case, too, the magnetic flux of the permanent magnet flows more easily through the magnetic circuit passing through the movable iron piece, thereby increasing the holding force for retaining the movable iron piece in the operating position.

[0012] The section with reduced cross-sectional area may have a thickness smaller than the thickness of the second contact section. In this case, too, the magnetic flux of the permanent magnet flows more easily through the magnetic circuit passing through the movable iron piece, thereby increasing the holding force for retaining the movable iron piece in the operating position.

[0013] The auxiliary yoke may include a magnetic contact portion configured to contact the permanent magnet, a yoke contact portion configured to contact the yoke, an intermediate portion located between the magnetic contact portion and the yoke contact portion and spaced apart from the yoke in the axial direction, and a first step formed between the intermediate portion and the yoke contact portion. In this case, a magnetic circuit passing through the yoke and the auxiliary yoke can be easily formed.

[0014] The auxiliary yoke may further include a second step formed between the magnetic contact portion and the intermediate portion. The permanent magnet may contact the second step. In this case, the auxiliary yoke may be positioned by the second step.

[0015] The yoke contact portion of the auxiliary yoke may have a curved shape. In this case, the magnetic circuit passing through the yoke and the auxiliary yoke can be formed with a simple structure.

[0016] The second contact portion of the base portion of the yoke may have a shape that protrudes toward the yoke contact portion and may contact the yoke contact portion. In this case, the magnetic circuit passing through the yoke and the auxiliary yoke can also be formed with a simple structure.

[0017] The auxiliary yoke can be integral with the yoke. In this case, the number of components can be reduced.

[0018] The movable iron piece may include an attraction portion designed to be attracted toward the iron core. The attraction portion may include a recess recessed in a direction away from the iron core. In this case, the surface of the attraction portion opposite the iron core is reduced, and the magnetic flux flowing from the iron core to the movable iron piece is concentrated, thereby increasing the holding force for retaining the movable iron piece in the operating position.

[0019] The attraction portion may further include a first projection that can be brought into contact with the iron core. In this case, the surface area of ​​the attraction portion that is opposite to the iron core can be reduced, thereby increasing the holding force for retaining the movable iron piece in the operating position.

[0020] The movable iron piece may include an attraction portion intended to be attracted toward the iron core. The attraction portion may include a through hole penetrating in the axial direction. In this case, the surface area of ​​the attraction portion located opposite the iron core is reduced, thereby increasing the holding force for retaining the movable iron piece in the operating position.

[0021] The roller may include a positioning portion configured to position the auxiliary yoke. The positioning portion may include a first side wall and a second side wall facing the first side wall. The auxiliary yoke may be held between the first and second side walls. In this case, the auxiliary yoke can be easily positioned.

[0022] According to the claimed invention, the assemblability of the electromagnet device can be improved. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a side view of an electromagnetic relay. Fig. 2 is a partial cross-sectional view of an electromagnet device. Fig. 3 is a bottom view of a yoke. Fig. 4 is a diagram showing a positioning section. Fig. 5 is a diagram showing an operating state of the electromagnet device. Fig. Figure 6 is a diagram showing a modification of a section with reduced cross-sectional area. Fig. Figure 7 is a diagram showing a modification of a section with reduced cross-sectional area. Fig. Figure 8 is a diagram showing a modification of a yoke and an auxiliary yoke. Fig. Figure 9 is a diagram showing a modification of a yoke and an auxiliary yoke. Fig. 10 is a diagram showing a modification of an attraction portion of a movable iron piece. Fig. 11 is a diagram showing a modification of an attraction portion of a movable iron piece. Fig. 12 is a diagram showing a modification of an attraction portion of a movable iron piece. DETAILED DESCRIPTION

[0023] An embodiment of an electromagnetic relay according to one aspect of the claimed invention will be described below with reference to the drawings. For convenience of description with reference to the drawings, the upper side is Fig. 1 is called “top”, the bottom side is called “bottom”, the left side is called “left”, the right side is called “right”, the near side of the sheet is called “front” and the far side is called “back”.

[0024] Electromagnetic relay 1 is a joint-type electromagnetic relay. Electromagnetic relay 1 is a self-holding electromagnetic relay. As shown in Fig. 1, the electromagnetic relay 1 includes a base 2, a contact device 3, and an electromagnet device 4. The base 2 is made of an insulating material, such as resin. A box-shaped cover member (not shown) is located above the base 2. The contact device 3 and the electromagnet device 4 are located in an interior space formed by the base 2 and the cover member.

[0025] The contact device 3 includes a fixed terminal 6, a movable contact piece 7, and an actuating mechanism 8. The fixed terminal 6 and the movable contact piece 7 are plate terminals and are made of conductive material. The fixed terminal 6 and the movable contact piece 7 are supported by the base 2 and extend upward from the base 2.

[0026] The fixed terminal 6 includes a fixed contact 6a and an external connection portion 6b. The fixed contact 6a is located above the base 2 and lies on the right surface of the fixed terminal 6.

[0027] The external connection portion 6b protrudes downward from the base 2 and is exposed to the outside. The external connection portion 6b is to be electrically connected to an external device (not shown).

[0028] The movable contact piece 7 is formed of an elastically deformable leaf spring and is arranged opposite the fixed terminal 6 in the left-right direction. In the present embodiment, the movable contact piece 7 is located to the left of the fixed terminal 6.

[0029] The movable contact piece 7 includes a movable contact 7a and an external connection portion 7b. The movable contact 7a is arranged opposite the fixed contact 6a and is designed to come into contact with the fixed contact 6a. The external connection portion 7b is electrically connected to an external device (not shown).

[0030] The actuating mechanism 8 moves the movable contact piece 7 in a direction in which the movable contact 7a approaches the fixed contact 6a and in a direction in which the movable contact 7a separates from the fixed contact 6a. In the present embodiment, the movement directions of the movable contact piece 7 correspond to the left-right direction.

[0031] The actuating mechanism 8 includes a card 10. The card 10 is rotatably supported by the base 2. The card 10 is rotatable in the left-right direction, with the lower end of the card 10 serving as the pivot point. The card 10 is located between the movable contact piece 7 and the electromagnet device 4. The card 10 is connected to both the movable contact piece 7 and the electromagnet device 4.

[0032] The electromagnet device 4 uses electromagnetic force to move the movable contact piece 7 via the actuating mechanism 8. The electromagnet device 4 rotates the card 10 through electromagnetic force, thereby moving the movable contact piece 7 in the left-right direction.

[0033] According to the presentation in the Fig. 1 to 3, the electromagnet device 4 includes a coil 41, a roller 42, an iron core 43, a yoke 44, an auxiliary yoke 45, a permanent magnet 46, a movable iron piece 47, and a hinge spring 48.

[0034] The spool 41 is wound around the outer circumference of the roller 42. The roller 42 extends in the up-down direction. The axial direction of the roller 42 corresponds to the up-down direction. The roller 42 includes a first flange 51, a second flange 52, a body portion 53, a housing portion 54, and a positioning portion 55 (see Fig. 4).

[0035] The first flange 51 is connected to the upper end of the body portion 53. The second flange 52 is connected to the lower end of the body portion 53. The first flange 51 and the second flange 52 extend in a direction intersecting the up-down direction. The first flange 51 and the second flange 52 each have an outer diameter larger than the outer diameter of the body portion 53.

[0036] The body portion 53 has a cylindrical shape, and the coil 41 is wound around its outer circumference. The body portion 53 extends in the up-down direction.

[0037] The housing portion 54 is located within the body portion 53. The housing portion 54 is a circular hole when viewed from the up-down direction. The housing portion 54 is formed by the central portion of the body portion 53 in the up-down direction.

[0038] According to the presentation in Fig. 4, the positioning section 55 is designed to position the auxiliary yoke 45. The positioning section 55 is arranged below the second flange 52. The positioning section 55 extends downward from the outer edge of the second flange 52. The positioning section 55 has a recessed shape extending from left to right. The positioning section 55 is open on the right and bottom sides.

[0039] Specifically, the positioning portion 55 includes a first side wall 55a, a second side wall 55b, and a connecting portion 55c. The first side wall 55a and the second side wall 55b extend in a direction intersecting the front-back direction. The second side wall 55b is disposed opposite to the first side wall 55a in the front-back direction. The second side wall 55b is located rearward of the first side wall 55a. The connecting portion 55c is connected to the left end of the first side wall 55a and the left end of the second side wall 55b. The front portion 55c extends in the front-back direction.

[0040] The iron core 43 is located inside the roller 42. The iron core 43 is housed in the housing portion 54. The upper end of the iron core 43 is exposed from the housing portion 54. The lower end of the iron core 43 is fixed to the yoke 44 by caulking. The axis A of the iron core 43 extends in the up-down direction. In the present embodiment, the axial direction of the iron core 43 corresponds to the up-down direction.

[0041] The yoke 44 is connected to the iron core 43, the auxiliary yoke 45, and the permanent magnet 46. The yoke 44 has a curved L-shaped configuration. The yoke 44 rotatably supports the movable iron piece 47. The yoke 44 includes a base portion 61 and an extension portion 62.

[0042] The base portion 61 extends in a direction intersecting the up-down direction. The base portion 61 is located below the second flange 52. The base portion 61 is fixed to the lower end of the iron core 43 via a caulking hole 63, which will be described later. The base portion 61 is positioned by the positioning portion 55. The base portion 61 is located between the first side wall 55a and the second side wall 55b.

[0043] The base portion 61 includes the caulking hole 63, a first contact portion 64, a second contact portion 65, and a reduced cross-sectional area portion 66.

[0044] The caulking hole 63 penetrates the base portion 61 in the up-down direction. The caulking hole 63 also penetrates the first contact portion 64 in the up-down direction. The caulking hole 63 has a counterbore shape.

[0045] The first contact portion 64 is located above the permanent magnet 46 and contacts the permanent magnet 46. The lower surface of the first contact portion 64 contacts the upper surface of the permanent magnet 46. The first contact portion 64 is located near the caulking hole 63. A part of the first contact portion 64 is located in front of the caulking hole 63.

[0046] The second contact portion 65 is located above the auxiliary yoke 45 and contacts the auxiliary yoke 45. The lower surface of the second contact portion 65 contacts the upper surface of the auxiliary yoke 45. The second contact portion 65 is spaced apart from the first contact portion 64 in the left-right direction. The second contact portion 65 is located to the right of the first contact portion 64 and the caulking hole 63. The second contact portion 65 is closer to the extension portion 62 than to the first contact portion 64.

[0047] The reduced cross-sectional area portion 66 is located between the first contact portion 64 and the second contact portion 65. The cross-sectional area of ​​the reduced cross-sectional area portion 66 is smaller than that of the second contact portion 65. The cross-sectional area refers to the surface area of ​​a cross section along a plane orthogonal to the left-right direction. The reduced cross-sectional area portion 66 is spaced apart from the auxiliary yoke 45 in the up-down direction.

[0048] According to the presentation in Fig. 3, the reduced cross-sectional area portion 66 includes a first connecting portion 66a, a second connecting portion 66b, and a through hole 66c. The first connecting portion 66a and the second connecting portion 66b extend in the left-right direction. The first connecting portion 66a and the second connecting portion 66b are connected to the first contact portion 64 and the second contact portion 65. The first connecting portion 66a is located in front of the caulking hole 63. The second connecting portion 66b is spaced apart from the first connecting portion 66a in the front-back direction. The second connecting portion 66b is located behind the caulking hole 63.

[0049] The through-hole 66c is located between the first connecting portion 66a and the second connecting portion 66b. The through-hole 66c penetrates the base portion 61 in the up-down direction. The through-hole 66c extends in the front-back direction. The through-hole 66c has a width dimension that is larger than the inner diameter dimension of the caulking hole 63. The width dimension of the through-hole 66c refers to its dimension in the front-back direction. The through-hole 66c is located to the right of the permanent magnet 46. It should be noted that in Fig. 3 the position of the permanent magnet 46 is shown schematically.

[0050] The extension portion 62 extends in a direction intersecting the left-right direction. The extension portion 62 is connected to the base portion 61. The extension portion 62 includes a portion that extends upward in a curved manner from the right end of the base portion 61. The extension portion 62 is located on the right side of the coil 41.

[0051] The auxiliary yoke 45 is connected to the base portion 61 of the yoke 44 on the outside of the base portion 61. The auxiliary yoke 45 is located below the base portion 61 of the yoke 44. In the up-down direction, the auxiliary yoke 45 is located between the base portion 61 of the yoke 44 and the base 2. The auxiliary yoke 45 contacts the second contact portion 65 of the base portion 61 of the yoke 44 and the permanent magnet 46. The auxiliary yoke 45 is held between the first side wall 55a and the second side wall 55b.

[0052] The auxiliary yoke 45 includes a magnetic contact portion 71, an intermediate portion 72, and a yoke contact portion 73. The magnetic contact portion 71 is configured to contact the permanent magnet 46. The magnetic contact portion 71 is located below the first connecting portion 66a and the caulking hole 63. When viewed from the up-down direction, the magnetic contact portion 71 overlaps the first connecting portion 66a and the caulking hole 63.

[0053] The intermediate portion 72 is located between the magnetic contact portion 71 and the yoke contact portion 73. The intermediate portion 72 is spaced apart in the up-down direction from the base portion 61 of the yoke 44, and a space is formed between the intermediate portion 72 and the base portion 61. The intermediate portion 72 is located below the reduced cross-sectional area portion 66 of the yoke 44. When viewed from the up-down direction, the intermediate portion 72 overlaps the reduced cross-sectional area portion 66. The intermediate portion 72 is spaced apart in the up-down direction from the reduced cross-sectional area portion 66. The intermediate portion 72 protrudes upward from the magnetic contact portion 71, and a step 74 (an example of the second step) is formed between the intermediate portion 72 and the magnetic contact portion 71.

[0054] The yoke contact portion 73 is located to the right of the intermediate portion 72. The yoke contact portion 73 is configured to contact the yoke 44. The yoke contact portion 73 contacts the second contact portion 65 of the yoke 44. The yoke contact portion 73 protrudes upwardly beyond the intermediate portion 72, and a step 75 (an example of the first step) is formed between the yoke contact portion 73 and the intermediate portion 72.

[0055] The permanent magnet 46 extends in a direction intersecting the up-down direction. The permanent magnet 46 has a width dimension larger than the inner diameter dimension of the caulking hole 63. The permanent magnet 46 is positioned on the extension line of the axis A of the iron core 43. The permanent magnet 46 is located between the base portion 61 of the yoke 44 and the auxiliary yoke 45. Specifically, the permanent magnet 46 is located between the first contact portion 64 of the yoke 44 and the magnetic contact portion 71 of the auxiliary yoke 45. The upper surface of the permanent magnet 46 contacts the first contact portion 64, and the lower surface contacts the magnetic contact portion 71. The permanent magnet 46 is located below the caulking hole 63. The permanent magnet 46 overlaps the caulking hole 63 when viewed from the up-down direction.The permanent magnet 46 is located to the left of the section 66 with reduced cross-sectional area.

[0056] The permanent magnet 46 is spaced apart from the iron core 43 in the up-down direction. The permanent magnet 46 can be arranged such that the center of the cross section of the permanent magnet 46 is aligned with the extension of the axis A of the iron core 43. The permanent magnet 46 is positioned by the step 74; the left side of the permanent magnet 46 is in contact with the step 74. The permanent magnet 46 also protrudes upward beyond the intermediate portion 72 of the auxiliary yoke 45.

[0057] The movable iron piece 47 is rotatably supported on the extension portion 62 of the yoke 44 via a hinge spring 48. The movable iron piece 47 is movable between a first position (illustrated in Fig. 1) and a second position (illustrated in Fig. 5) rotatable. In the first position, the movable iron piece 47 is separated from the iron core 43. In the second position, the movable iron piece 47 is in contact with the iron core 43. The second position corresponds to the operating position of the movable iron piece 47.

[0058] The movable iron piece 47 includes an attraction portion 81, a bent portion 82, and a pressing portion 83. The attraction portion 81 is arranged opposite the upper end of the iron core 43 in the up-down direction. The attraction portion 81 is configured to contact the iron core 43 in the second position.

[0059] The attraction portion 81 includes a first protrusion 81a, a second protrusion 81b, and a recess 81c. The first protrusion 81a contacts the iron core 43 in the second position. The first protrusion 81a is located at the front end (left end) of the attraction portion 81. When viewed from the axial direction of the iron core (up-down direction), the first protrusion 81a overlaps the permanent magnet 46. The second protrusion 81b does not contact the iron core 43 in the second position. The second protrusion 81b does not overlap the permanent magnet 46 when viewed from the axial direction of the iron core (up-down direction). The first and second protrusions are spaced apart from each other in the left-right direction. The recess 81c has a shape recessed in a direction away from the iron core 43. The recess 81c is located between the first projection 81a and the second projection 81b.The recess 81c extends in the front-backward direction. When the movable iron piece 47 is in the second position, the recess 81c overlaps the upper end of the iron core 43 when viewed from the up-down direction. When the movable iron piece 47 is in the second position, the recess 81c lies on an extension line of the axis A of the iron core 43. When the movable iron piece 47 is in the second position, the recess 81c is positioned opposite the upper end of the iron core 43 and spaced from the iron core 43. The recess 81c does not contact the iron core 43 when the movable iron piece 47 is in the second position.

[0060] The bent portion 82 is located at the upper end of the extension portion 62 of the yoke 44. The pressing portion 83 is connected to the card 10 and is configured to press the card 10 from the first position to the second position according to the movement of the movable iron piece 47.

[0061] The hinge spring 48 is fixed to the extension portion 62 of the yoke 44. The hinge spring 48 on the extension portion 62 of the yoke 44 serves to hold the movable iron piece 47.

[0062] The operation of the electromagnetic relay 1 will be described below. Since the operation of the electromagnetic relay 1 is similar to that of a conventional relay, it will be briefly described. While no voltage is applied to the coil 41, the movable iron piece 47 is positioned in the first position by the spring force of the movable contact piece 7, and the movable contact 7a is separated from the fixed contact 6a. In this state, the magnetic flux of the permanent magnet 46 generates a magnetic circuit M1 passing through the auxiliary yoke 45 and the base portion 61 of the yoke 44, and a magnetic circuit M2 passing through the iron core 43, the movable iron piece 47, the yoke 44, and the auxiliary yoke 45.

[0063] When a voltage is applied to the coil 41 to generate a magnetic flux in the same direction as the magnetic flux flowing through the magnetic circuit M2, a magnetic circuit is formed by the iron core 43, the movable iron piece 47, and the yoke 44 by the magnetic flux generated by the voltage applied to the coil 41. As a result, the attractive force of the iron core 43 acting on the movable iron piece 47 increases, causing the movable iron piece 47 to rotate and move from the first position to the second position. When the movable iron piece 47 moves from the first position to the second position, the card 10 is pressed by the movable iron piece 47, and the movable contact 7a comes into contact with the fixed contact 6a.

[0064] Even after the application of voltage to the coil 41 is stopped, the magnetic force of the magnetic circuit M2 is greater than the spring force of the movable contact piece 7, and thereby the movable iron piece 47 is maintained at the second position.

[0065] When a reverse voltage is applied to the coil 41 in the direction opposite to the applied voltage to cancel the magnetic force of the magnetic circuit M2, the movable iron piece 47 moves from the second position to the first position, causing the movable contact 7a to separate from the fixed contact 6a.

[0066] In the electromagnet device 4 of the electromagnetic relay 1 described above, the auxiliary yoke 45 is connected to the base portion 61 of the yoke 44 on the outside of the base portion 61, and the permanent magnet 46 is located between the base portion 61 of the yoke 44 and the auxiliary yoke 45. That is, the auxiliary yoke 45 and the permanent magnet 46 are arranged on the outside of the yoke 44. With this configuration, the permanent magnet 46 and the auxiliary yoke 45 can be assembled on the outside of the yoke 44, thereby improving the assemblability of the electromagnet device 4. Furthermore, the electromagnet device 4 according to the claimed invention can be easily assembled, for example, by attaching the permanent magnet 46 and the auxiliary yoke 45 from the outside to a conventional hinge-type, single-stable electromagnet device 4.Furthermore, the usual components of the conventional articulated, single-stable electromagnet device can be used except for the permanent magnet 46 and the auxiliary yoke 45.

[0067] An embodiment of the electromagnetic relay according to one aspect of the claimed invention has been described above. However, the claimed invention is not limited to this embodiment, and various modifications may be made without departing from the scope of the claimed invention.

[0068] The shape of the yoke 44 may be changed. The reduced cross-sectional area portion 66 of the yoke 44 may include a narrowed portion. In particular, the reduced cross-sectional area portion 66 may include a narrowed portion 66d, as shown in Fig. 6. The narrowed portion 66d may have a width dimension smaller than that of the permanent magnet 46. The narrowed portion 66d may have a width dimension similar to the inner diameter dimension of the caulking hole 63. The reduced cross-sectional area portion 66 may also have a smaller thickness than the second contact portion 65. As shown in Fig. 7, the narrowed portion 66d may have a recessed shape on the lower surface of the base portion 61.

[0069] The shape of the auxiliary yoke 45 can also be changed. The step 74 can be omitted, and the intermediate section 72 can be directly connected to the magnetic contact section 71 without steps. The yoke contact section 73 can have a curved L-shaped design. As shown in Fig. 8, the yoke contact portion 73 may include a part extending from the right end of the intermediate portion 72 in a bent manner to contact the second contact portion 65.

[0070] The auxiliary yoke 45 may have a flat upper surface and the intermediate portion 72 is directly connected to the magnetic contact portion 71 and the yoke contact portion 73 without steps. In this case, as shown in Fig. 9, the second contact portion 65 of the yoke 44 may have a shape that protrudes toward the yoke contact portion 73.

[0071] According to the presentation in Fig. 10, the auxiliary yoke 45 may be integral with the yoke 44. For example, the auxiliary yoke 45 may be formed integrally with the yoke 44 by folding a part of the yoke 44.

[0072] The design of the movable iron piece 47 can also be changed. According to the illustration in Fig. 11, the second projection 81b and the recess 81c of the attraction portion 81 in the movable iron piece 47 may be omitted. That is, the tip of the attraction portion 81 may protrude toward the yoke contact portion 73. As shown in Fig. 12, the attraction portion 81 may also include a through hole 81d extending in the axial direction.

[0073] The design of the contact device 3 can be changed. The claimed invention can be applied to a contact device in which the movable contact 7a rotates integrally with the movable iron piece 47. The orientation of the electromagnet device 4 can also be changed. The electromagnet device 4 can be arranged such that the axial direction of the iron core 43 corresponds to the left-right direction.

[0074] In the embodiment described above, the auxiliary yoke 45 is positioned by the roller 42. However, the auxiliary yoke 45 may instead be positioned by the yoke 44. For example, the auxiliary yoke 45 may be fixed to the yoke 44 by engaging the base portion 61 of the yoke 44 in a concave-convex fit arrangement. REFERENCE SYMBOL

[0075] 1: Electromagnetic relay; 41: Coil, 42: Roller, 43: Iron core, 44: Yoke, 45: Auxiliary yoke, 46: Permanent magnet, 47: Movable iron piece, 61: Base section, 62: Expansion section, 63: Caulking hole, 64: First contact section, 65: Second contact section, 66: Reduced cross-sectional area section, 66c: Through hole, 66d: Narrowed section, 71: Magnetic contact section, 72: Intermediate section, 73: Yoke contact section, 81: Attraction section

Claims

[1] Electromagnetic device comprising: a coil; a roller around which the spool is wound; an iron core located inside the roll; a yoke including a base portion and an extension portion, the base portion extending in a direction intersecting an axial direction of the iron core and fixed to one end of the iron core, the extension portion being connected to the base portion and arranged laterally relative to the coil; a movable iron piece rotatably supported by the extension portion of the yoke; an auxiliary yoke connected to the base portion of the yoke at an outer side of the base portion; and a permanent magnet positioned on an extension line of an axis of the iron core and located between the base portion of the yoke and the auxiliary yoke. [2] Electromagnetic device according to claim 1, wherein the base portion of the yoke includes a first contact portion configured to contact the permanent magnet, a second contact portion configured to contact the auxiliary yoke, and a reduced cross-sectional area portion located between the first contact portion and the second contact portion, and the reduced cross-sectional area portion is spaced apart from the auxiliary yoke in the axial direction and has a smaller cross-sectional area than a cross-sectional area of ​​the second contact portion. [3] The electromagnet device according to claim 2, wherein the reduced cross-sectional area portion includes a through hole penetrating the base portion in the axial direction. [4] Electromagnetic device according to claim 3, wherein the base portion further includes a caulking hole, and the through hole of the reduced cross-sectional area section has a width dimension that is larger than an inside diameter dimension of the caulking hole. [5] Electromagnetic device according to claim 2, wherein the section with reduced cross-sectional area includes a narrowed section, and the narrowed portion has a width dimension that is smaller than a width dimension of the permanent magnet. [6] The electromagnet device according to claim 2, wherein the reduced cross-sectional area portion has a thickness smaller than a thickness of the second contact portion. [7] The electromagnet device according to claim 2, wherein the auxiliary yoke includes a magnetic contact portion configured to contact the permanent magnet, a yoke contact portion configured to contact the yoke, an intermediate portion located between the magnetic contact portion and the yoke contact portion and spaced apart from the yoke in the axial direction, and a first step formed between the intermediate portion and the yoke contact portion. [8] Electromagnetic device according to claim 7, wherein the auxiliary yoke further includes a second step formed between the magnetic contact portion and the intermediate portion, and the permanent magnet touches the second stage. [9] The electromagnet device according to claim 7, wherein the yoke contact portion of the auxiliary yoke has a curved shape. [10] The electromagnet device according to claim 7, wherein the second contact portion of the base portion of the yoke has a shape protruding toward the yoke contact portion and configured to contact the yoke contact portion. [11] The electromagnet device according to claim 1, wherein the auxiliary yoke is integral with the yoke. [12] Electromagnetic device according to claim 1, wherein the movable iron piece includes an attraction portion designed to be attracted toward the iron core, and the attraction portion includes a recess which is recessed in a direction away from the iron core. [13] Electromagnetic device according to claim 1, wherein the movable iron piece includes an attraction portion designed to be attracted toward the iron core, and the attraction portion further includes a first projection that can be brought into contact with the iron core. [14] Electromagnetic device according to claim 1, wherein the movable iron piece includes an attraction portion designed to be attracted toward the iron core, and the attraction portion includes a through hole penetrating in the axial direction. [15] Electromagnetic device according to claim 1, wherein the roller includes a positioning section designed to position the auxiliary yoke, the positioning portion includes a first side wall and a second side wall facing the first side wall, and the auxiliary yoke is held between the first side wall and the second side wall.

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