Electric magnet device and switch provided therewith |
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申请号 | EP13178744.2 | 申请日 | 2013-07-31 | 公开(公告)号 | EP2706551B1 | 公开(公告)日 | 2017-09-06 |
申请人 | OMRON CORPORATION; | 发明人 | Izawa, Kazuhira; Nagata, Kenshi; | ||||
摘要 | |||||||
权利要求 | |||||||
说明书全文 | The present invention relates to an electric magnet device, particularly to an electric magnet device that is used in a reset-function equipped switch used for a copying machine and the like. A conventional electric magnet device, for example, Japanese Unexamined Patent Publication No. However, in the electric magnet device, there has been a problem that when the distance between the centers of the leg parts is excessively less than the distance between the centers of the bobbin holes due to a variation of working accuracy of a component, the leg part has a difficulty in moving in the bobbin hole. The present invention has been devised to solve the problem described above, and an object thereof is to provide an electric magnet device, in which a smooth movement of the armature inside the bobbin is ensured and, even if a vibration or an impact is applied, an attraction state between the yoke and the armature is maintained to prevent a malfunction, and a switch provided with the electric magnet device. In accordance with one aspect of the present invention, in order to solve the problem described above, an electric magnet device according to claim 1 is provided. According to the present invention, because the yoke and the armature come into surface contact with each other, a magnetic resistance decreases, and the yoke and the armature can be attracted to each other with a large attractive force. Therefore, the smooth movement of the armature is ensured and, even if the vibration or the impact is applied, the attraction state between the yoke and the armature can be maintained to prevent the malfunction. According to an embodiment of the present invention, a ratio of the oscillation angle of the yoke to the oscillation angle of the armature may be greater than 1:1 and less than or equal to 3:1. According to the present invention, when the ratio of the oscillation angles of the yoke to the armature is less than or equal to 1:1, that is for example, 1:0.5, the yoke and the armature cannot be come into surface contact with each other, and the desired effect cannot be obtained. When the ratio of the oscillation angles of the yoke to the armature is greater than 3:1, that is for example, 4:1, in attracting the armature and the yoke to each other, a lower end portion of the armature comes into contact with a corner in an upper end portion of the yoke, and the attraction surface on the side of the armature is abraded to degrade the attractive force. Accordingly, the ratio of the oscillation angle of the yoke to the oscillation angle of the armature is preferably greater than 1:1 and less than or equal to 3:1, whereby the armature and the yoke come surely into surface contact with each other, and the abrasions of the attraction surfaces of the armature and the yoke can be controlled to prevent the degradation of the attractive force. According to another embodiment of the present invention, attraction surfaces of the armature and the yoke are having a square shape. Therefore, a degree of design freedom can be enhanced. According to a different embodiment of the present invention, attraction surfaces of the armature and the yoke may are having a circular shape. Therefore, a degree of design freedom can be enhanced. According to still another embodiment of the present invention, an assembly notch may be provided in each of both lateral edge portions of the yoke. According to the present invention, the yoke can easily be gripped through the assembly notch with such as a tool, thereby improving workability. In accordance with another aspect of the present invention, a switch may be provided with the electric magnet device described above.
A reset-function-equipped switch 1 incorporating an electric magnet device according to a first embodiment of the present invention is described with reference to the accompanying drawings of As illustrated in The housing 10 has a box shape with an upper portion being opened, and the housing 10 is configured such that the power switch mechanism 20 is disposed on one side of its inner space while the drive mechanism 40 is disposed on the other side of the inner space. The operation piece 13 has a substantially rectangular box shape with a lower surface being opened, and the operation piece 13 includes an operation surface 14, a support shaft 15, a retention part 16 (see The power switch mechanism 20 includes a first power switch mechanism 20a and a second power switch mechanism 20b, which are disposed in parallel in the housing 10. The first and the second power switch mechanism 20a, 20b includes the coupling body 21, a movable contact piece 23, a first fixed contact piece 31, and a second fixed contact piece 34. The coupling body 21 is composed of a coil spring bent into a chevron shape. As illustrated in As illustrated in first fixed contact piece 31 has a vertically reverse L-shape, and a first fixed contact 32 is formed in the upper surface of the first fixed contact piece 31 by cutting and raising the first fixed contact piece 31. Similarly, a second fixed contact piece 34 has a vertically reverse L-shape, and a second fixed contact 35 is attached to the upper surface of the second fixed contact piece 34. Because the second power switch mechanism 20b is composed of the same components as the first power switch mechanism 20a, the same component is designated by the same numeral, and the description thereof is omitted. As illustrated in The electric magnet device 41 includes a bobbin 43 that includes a vertically piercing through-hole 42, a coil 48 that is wound around the bobbin 43, a yoke 50 that is inserted through the through-hole 42 of the bobbin 43 from below, and the armature 71 that is inserted through the through-hole 42 of the bobbin 43 from above. The bobbin 43 includes two coil-winding parts 44 provided in parallel, an upper end edge part 45, and a lower end edge part 46. The coil winding part 44 is cylindrical having a rectangular shape in section, and the coil 48 is wound around an outer periphery of the coil winding part 44. The upper end edge part 45 is formed at the upper end of the coil winding part 44, and the upper end edge part 45 integrally connects the two coil winding parts 44. The lower end edge part 46 is composed of a rectangular frame body formed at the lower end of each coil winding part 44, a reset signal input terminal 55 to which a bound leads of the coil 48 is connected is press-fitted in and fixed to the lower end edge part 46. The yoke 50 is made of a plate-like magnetic material that enhances magnetic efficiency of a permanent magnet 56 (to be described). The yoke 50 also includes a pair of upwardly extending arm parts 51, a pair of notches 52 that are formed on the lower side of the lateral surface and curved inward into a U-shape, and a linear attaching hole 53 that is formed in the center so as to extend vertically. The rectangular-solid-shape permanent magnet 56 is fitted in and fixed to the he attaching hole 53. The case 60 includes a storage part 61 in which the electric magnet device 41 is stored, a pair of guide plates 62 formed above the storage part 61, and a socket 63 formed below the storage part 61. An upper-side latching protrusion 65 and a lower-side latching protrusion 66, which protrude outward, are formed in both side surfaces of the case 60. An insertion hole 67 (see As illustrated in The cover 77 has a lateral shape that can laterally be fitted in the case 60, and includes a pair of upper-side elastic arm parts 78 extending in parallel from both side edge portions on the upper side and a pair of lower-side elastic arm parts 79 extending in parallel from both side edge portions on the lower side. A horizontally extending upper-side latching hole 81 is made in the upper-side elastic arm part 78. A horizontally extending lower-side latching hole 82 is made in the lower-side elastic arm part 79. A method for assembling the drive mechanism 40 will be described as a preceding process of assembling the switch 1. The lead of the coil 48 wound around the outer peripheral surface of the coil winding part 44 of the bobbin 43 is bound and soldered to the reset signal input terminal 55 fixed to the lower end edge part 46. The permanent magnet 56 is fitted in the attaching hole 53 of the yoke 50, and the arm part 51 is inserted through the through-hole 42 of the bobbin 43 from below, thereby forming the electric magnet device 41 except the armature 71. Because the notch 52 is provided in the yoke 50, the yoke 50 can easily be gripped with a tool through the notch, thereby improving workability. Then the electric magnet device 41 is stored in the storage part 61 of the case 60. At this point, the upper end edge part 45 of the bobbin 43 abuts on the linear protrusion 68, and abuts on the ceiling surface of the storage part 61. Additionally, the lower end edge part 46 abuts on the upper side surface of the plate-like protrusion 69, whereby the electric magnet device 41 is positioned in the storage part 61 (case 60). At this point, the yoke 50 is retained and fitted in the storage part 61 with a play, so that the yoke 50 can oscillate with the arm part 51 being inserted through the through-hole 42. Accordingly, surface contact between the arm part 51 and the leg part 73 of the armature 71 is facilitated. As illustrated in Then the cover 77 is mounted to the case 60 so as to cover the opening lower side of the case 60 and the socket 63. At this point, the upper-side latching hole 81 of the cover 77 is latched in the upper-side latching protrusion 65 of the case 60, and the lower-side latching hole 82 is latched in the lower-side latching protrusion 66, thereby retaining the electric magnet device 41. Finally the armature 71 is inserted through the through-hole 42 of the bobbin 43 through the insertion hole 67 of the case 60 while the return spring 75 disposed above the storage part 61 is interposed between the armature 71 and the through-hole 42, thereby completing the drive mechanism 40. Then, as illustrated in An operation of the switch 1 will be described below. As illustrated in As illustrated in When the switch 1 is turned on, the coupling body 21 of the power switch mechanism 20 is bent into the chevron shape toward the opposite side to the drive mechanism 40. Therefore, the protrusion 25 is pressed onto the right side in As illustrated in In the embodiment of the present invention, a ratio of an oscillation angle of the yoke 50 to an oscillation angle of the armature 71 is preferably greater than 1:1 and less than or equal to 3:1. When the ratio of the oscillation angles of the yoke 50 to the armature 71 is less than or equal to 1:1, that is for example, 1:0.5, the leg part 73 and the arm part 51 cannot be come into surface contact with each other, and the desired effect cannot be obtained. When the ratio of the oscillation angles of the yoke 50 to the armature 71 is greater than 3:1, that is for example, 4:1, in attracting the armature 71 and the yoke 50 to each other, the lower end portion of the leg part 73 comes into contact with an upper-end corner portion of the arm part 51, and an attraction surface on the side of the armature 71 is abraded to degrade the attractive force. Accordingly, when the ratio of the oscillation angle of the yoke 50 to the oscillation angle of the armature 71 is greater than 1:1 and less than or equal to 3:1, the leg part 73 and the arm part 51 come surely into surface contact with each other, and the abrasions of the attraction surfaces of the leg part 73 and the arm part 51 can be controlled to prevent the degradation of the attractive force. In the present embodiment, the attraction surfaces of the leg part 73 and the arm part 51 are formed into the square shape, but are not limited thereto. The same effect is obtained even if the attraction surfaces of the leg part 73 and the arm part 51 are formed into a circular shape. The square shape or the circular shape of the attraction surfaces enhances a degree of design freedom. When a voltage that generates the reverse magnetic force is applied to the coil 48 through the reset signal input terminal 55 in order to turn off the switch 1 in the on state, a magnetic flux of the permanent magnet 56 is canceled to relatively lower the magnetic force between the armature 71 and the yoke 50. Therefore, the armature 71 is pushed upward by the elastic force of the return spring 75, and the upper end surface of the armature 71 pushes up the abutment plate 17. As a result, the operation piece 13 turns about the support shaft 15, and the power switch mechanism 20 returns to the off state illustrated in The present invention is not limited to the above embodiment, but various modifications can be made. In the above embodiment, as to the yoke 50 and the armature 71, the arm part 51 and the leg part 73 are inserted through the through-hole 42 of the bobbin 43, but not limited thereto. Alternatively, for example, in an electric magnet device according to a second embodiment illustrated in As another example, in an electric magnet device according to a third embodiment illustrated in The electric magnet device 41 of the first embodiment includes the pair of coils 48, the yoke 50 including the pair of arm parts 51, and the armature 71 including the pair of leg parts 73, but not limited thereto. Alternatively, for example, a configuration in which the electric magnet device includes the one coil, the yoke includes the one arm part, and the armature includes the one leg part may be employed. The electric magnet device of the present invention can of course be applied not only to the switch but also to other electric instruments. |