Contact point device and electromagnetic relay

Abstract

A contact point device configured to switch an electric current by means of a relative movement between a movable section (6) and a fixed section (5), causing it to flow or not, the contact point device comprising: a first contact device (71) provided on a surface between the movable section (6) and the fixed section (5) as a conductive contact element, having an outer side surface (711) shaped in the form of a column surrounding a central axis along a relative direction of movement of the movable section (6) and the fixed section (5); an oscillation-supporting section (73) that supports the first contact device (71) on the surface between the movable section (6) and the fixed section (5) to enable the central axis to oscillate; and a second contact device (72).which is provided on the other from the movable section (6) and the fixed section (5) as a conductive contact element, which is provided in the relative direction of movement to the first contact device (71) in order to be electrically connected to the first contact device (71) by coming into contact with the first contact device (71), wherein one of the first contact device (71) and the second contact device (72) has a plurality of first contact sections (761) which are provided to surround the central axis on a plane perpendicular to the central axis, the other of the first contact device (71) and the second contact device (72) has a second contact section (762) which is provided to project in the relative direction of movement to a space which is surrounded by the plurality of the first contact sections (761), and the second contact section (762) has a contact surface (763),which is a curved surface exposed to the space surrounding the central axis.

Description

TECHNICAL FIELDThe present disclosure relates to a contact point device and an electromagnetic relay.PRIOR ARTA contact point apparatus described in JP 2012-199 117 A has two fixed contact points and a movable contact device having two movable contact points. A slot is formed in one of the movable contact points. The fixed contact point corresponding to the one of the movable contact points comes into contact with the one of the movable contact points on both sides of the slot. As a result, the contact state between the movable contact device and the fixed contact point is stabilized.Specifically, the contact point device is configured to switch an electric current to flow or not by a relative movement between a movable portion and a fixed portion, the contact point device comprising:a first contact device provided on one of the movable portion and the fixed portion as a conductive contact member having an outer side surface shaped in a column shape surrounding a central axis along a relative moving direction of the movable portion and the fixed portion;a second contact device provided on the other of the movable portion and the fixed portion as a conductive contact member provided opposite to the first contact device in the relative moving direction.The publication JP 2008-84 807 A discloses a further contact point device of the generic type.SUMMARYThis type of apparatus is used, for example, on an electric vehicle such as a hybrid vehicle to turn on or off an electric circuit between a motor drive circuit and a battery. In conventional electric vehicles, the current between the motor drive circuit and the battery tends to increase as the travel performance increases. Therefore, in this type of apparatus, it is necessary to further reduce the contact resistance between the contact points. The present disclosure has been made in consideration of the above-exemplified circumstances, and an object thereof is to provide a contact point device and an electromagnetic relay.The object of the invention is achieved by a contact point device according to claim 1 and by a relay according to claim 8. Advantageous embodiments are the subject of the dependent claims.The contact point device is configured to switch an electric current to flow or not by relative movement between a movable portion and a fixed portion.The contact point device has:a first contact means provided on one of the movable portion and the fixed portion as a conductive contact member, having an outer side surface formed in a column surrounding a central axis along a relative moving direction of the movable portion and the fixed portion;an oscillation supporting portion that supports the first contact device on the one of the movable portion and the fixed portion to allow the central axis to oscillate;A second contact device provided on the other of the movable portion and the fixed portion as a conductive contact member provided opposite to the first contact device in the relative moving direction so as to be electrically connected to the first contact device by abutting against the first contact device.One of the first contact device and the second contact device has a plurality of first contact portions. The plurality of first contact portions are provided to surround the central axis on a plane perpendicular to the central axis.The other of the first contact device and the second contact device, which is different from the one of the first contact device and the second contact device, has a second contact portion. The second contact portion protrudes in the relative movement direction to a space surrounded by the plurality of first contact portions.The second contact portion has a contact surface that is a curved surface exposed to the space to surround the central axis.In another aspect of the present disclosure, an electromagnetic relay is configured to switch an electric current to flow or not by a movement of a movable portion relative to a fixed portion in a coil axis direction from a energization state of a coil.The electromagnetic relay has:a first contact device provided on one of the movable portion and the fixed portion as a conductive contact member having an outer side surface formed in a column shape surrounding a center axis along the coil axis direction;an oscillation supporting portion that supports the first contact device on the one of the movable portion and the fixed portion to allow the central axis to oscillate;a second contact device provided on the other of the movable portion and the fixed portion as a conductive contact member provided opposite to the first contact device in the coil axis direction so as to be electrically connected to the first contact device by abutting against the first contact device.One of the first contact device and the second contact device has a plurality of first contact portions. The plurality of first contact portions are provided to surround the central axis on a plane perpendicular to the central axis.The other of the first contact device and the second contact device, which is different from the one of the first contact device and the second contact device, has a second contact portion. The second contact portion protrudes in the coil axis direction to a space surrounded by the plurality of first contact portions.The second contact portion has a contact surface that is a curved surface exposed to the space to surround the central axis.BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1 is a cross-sectional view illustrating a schematic configuration of an electromagnetic relay and a contact point device according to an embodiment.FIG. 2 is an enlarged perspective view illustrating a part of a contact point device shown in FIG. 1.FIG. 3 is a cross-sectional view of the contact point device shown in FIG. 2.FIG. 4 is an enlarged bottom view illustrating an edge of the first contact portion seen from FIG. 2.FIG. 5 is a perspective view illustrating a schematic configuration of a contact point device according to a modification of the embodiment.FIG. 6 is a bottom view or a top view illustrating a second contact device shown in FIG. 5.FIG. 7 is a perspective view illustrating a schematic configuration of a contact point device of another modification of the embodiment.FIG. 8 is a side view illustrating a first contact device and an oscillation supporting portion shown in FIG. 7.FIG. 9 is a plan view and a bottom view of the first contact device and the oscillation supporting portion shown in FIG. 8.FIG. 10 is a cross-sectional view illustrating a schematic configuration of an electromagnetic relay and a contact point device according to another modification of the embodiment.DETAILED DESCRIPTIONHereinafter, an embodiment of the present disclosure will be described with reference to the drawings. Various modifications applicable to the embodiment will be collectively described as modifications after the description of the embodiment.(Schematic configuration of electromagnetic relay)The schematic configuration of the electromagnetic relay 1 according to the embodiment will be described with reference to FIG. 1. The electromagnetic relay 1 includes a housing 2, a frame 3, a coil 4, a fixed portion 5, and a movable portion 6. FIG. 1 shows a state in which the coil 4 is not energized.The electromagnetic relay 1 has a so-called plunger structure suitably applied to a power transmission path between a battery and a drive circuit for an electric motor in an electric vehicle. In the electromagnetic relay 1, the movable portion 6 moves relative to the fixed portion 5 along the coil axis direction according to the energization state of the coil 4, namely, linearly, thereby switching the electric current to allow the electric current to flow or not. The coil axis direction is a direction parallel to the coil axis L, which is the central axis of the coil 4.In FIG. 1, the Y-axis direction is taken as the coil axis direction in the XYZ three-dimensional coordinate system with the base right hand. Also, a direction parallel to the X axis is referred to as a "widthwise direction", and a direction parallel to the Z axis is referred to as a "height direction". A positive direction in the Y axis is referred to as a "return direction", and a negative direction in the Y axis is referred to as a "suction direction". The "coil axis direction" refers to a direction parallel to the Y axis and is used not to determine the return direction or the suction direction.The housing 2 is a bathtub-shaped member having an opening on one side in the height direction, and is integrally formed of an insulating material such as a synthetic resin. The frame 3 includes a disc-like portion (not shown) configured to close the opening of the housing 2, and a protruding portion protruding from the disc-like portion in the height direction. In Fig. 1, a part of the protruding portion of the frame 3 is shown. A shaft insertion hole 31, which is a through hole, is formed in the illustrated protruding portion along the coil axis direction.The coil 4, the fixed portion 5 and the movable portion 6 are supported by the frame 3. The coil 4, the fixed portion 5, and the movable portion 6 are accommodated inside the housing space HS. The housing space HS is a space surrounded by the housing 2 and the disc-like portion of the frame 3.The coil 4 is provided in an end portion (namely, an end portion in the suction direction) of the housing space HS. The coil 4 is configured to move relative to the movable portion 6 in the suction direction with respect to the fixed portion 5 by generating a magnetic field by energizing.The fixed portion 5 is fixed to the frame 3. A fixed core 51 of the fixed portion 5 is a cylindrically fixed magnetic path forming member formed of a ferromagnetic metal material and accommodated inside the coil 4. Namely, the fixed core 51 is disposed coaxially with the coil 4. A guide hole 52 is formed in the fixed core 51. The guide hole 52 penetrates the core 51 in the coil axis direction and is provided on the coil axis LA overlapping with the axial center of the fixed core 51.The movable portion 6 is configured to move in the suction direction by the magnetic field when the coil 4 is energized, and to move in the return direction when the energy of the coil 4 is decreased. Namely, the movable portion 6 is supported by the frame 3 and the fixed portion 5 to reciprocate along the coil axis direction.A movable core 61 of the movable portion 6 is a substantially disk-shaped member made of a ferromagnetic metal material and is provided opposite to the fixed core 51 in the return direction with respect to the fixed core 51. Namely, the movable core 61 is provided to move in the suction direction by being attracted to the fixed core 51 by the magnetic field when the coil 4 is energized. The movable core 61 is fixed to an intermediate portion of the movable shaft 62 in the longitudinal direction.The movable shaft 62 is a rod-like member having a longitudinal direction parallel to the coil axis LA, and is accommodated in the guide hole 52 of the fixed core 51 so as to be reciprocally movable along the coil axis direction. An end portion of the movable shaft 62 in the return direction is covered with a movable insulator 63 made of an insulating material such as a synthetic resin. The movable insulator 63 and an end portion of the movable shaft 62 covered with the movable insulator 63 are capable of reciprocating within the shaft insertion bore 31 along the coil axis direction.A return spring 64 is provided to surround the fixed core 51 in the suction direction of the movable core 61. The return spring 64, which is a compression coil spring, is provided so as to bias the movable core 61 away from the fixed core 51 in the return direction.(Configuration of Contact Point Device)The electromagnetic relay 1 has a contact point device 70. Next, with reference to FIGS. 1, 2, 3 to 4, the configuration of the contact point device 70 of the present embodiment will be described in detail.The contact point device 70 includes a first contact device 71, a second contact device 72, an oscillation supporting portion 73, a contact pressure spring 74, and a contact cover 75. In the present embodiment, the contact point device 70 is configured to switch the electric current to flow or not between the first contact device 71 and the second contact device 72 provided on the fixed portion 5 by relative movement between the first contact device 71 and the second contact device 72.The first contact device 71 is a conductive contact member formed of a conductive metal, and has an outer side surface 711 shaped in a column shape surrounding a central axis RA along the coil axis direction. In the present embodiment, the first contact device 71 is formed in a cylindrical shape having an axial direction substantially parallel to the coil axis LA. A distal end portion 712 of the first contact device 71 in the return direction is arranged to be directed in the coil axis direction in the second contact device 72.A flange portion 714 is formed in the intermediate portion 713 of the first contact device 71 in the longitudinal direction. The flange portion 714 protrudes outward from the outer side surface 711 (that is, in a direction away from the central axis RA). The flange portion 714 is covered with the oscillation supporting portion 73. The oscillation supporting portion 73 has an insulating elastic member provided in close contact with the outer side surface 711 of the first contact device 71, and is integrally formed of synthetic rubber or the like. The oscillation supporting portion 73 is fixed to the first contactor 71 such that the flange portion 714 restricts the relative movement of the oscillation supporting portion along the central axis RA with respect to the first contactor 71.The first contact device 71 is attached to the protruding portion of the frame 3 through the oscillation supporting portion 73. The first contact device 71 is not supported by the oscillation supporting portion 73 to allow the central axis RA to oscillate.In addition, in the present embodiment, the pair of first contact devices 71 are arranged in the widthwise direction. One and the other of the pair of first contact devices 71 are arranged substantially symmetrically with respect to the coil axis LA. The first contact devices 71 are electrically insulated from each other by the frame 3 and the oscillation supporting portion 73 in a state of being separated from the second contact device 72 in the coil axis direction. In the case where the electromagnetic relay 1 in the above-described application is mounted on an electric vehicle, one of the first contact devices 71 is electrically connected to a drive circuit for an electric motor, and the other is electrically connected to the battery.The second contact device 72 is a conductive contact member made of a conductive metal and is formed substantially in a flat disk shape having a thickness direction parallel to the coil axis direction. The second contact device 72 faces the first contact device 71 in the coil axis direction so as to be in electrical contact with the first contact device 71 that is in contact with the first contact device 71. In addition, the second contact device 72 is provided to be reciprocally movable along the coil axis direction while being guided by the frame 3. In the present embodiment, the second contact device 72 is disposed across the pair of first contact devices 71 in the widthwise direction to be in contact with the pair of first contact devices 71 to electrically connect the pair of first contact devices 71 to each other.An opposing surface 721 that is one of a pair of main surfaces of the second contact device 72 is provided to face the pair of first contact devices 71. A back surface 722, which is the other main surface of the second contact device 72, is provided to be in contact with the contact pressure spring 74.The contact pressure spring 74 is a compression coil spring, and is provided between the second contact device 72 and the contact cover 75 so as to bias the second contact device 72 toward the pair of first contact devices 71 in the suction direction. The contact cover 75 is made of an insulating material such as a synthetic resin, and is formed substantially in a U-shape to cover the pair of the first contact devices 71 and the second contact device 72. Both ends of the substantially U-shaped contact cover 75 are fixed to the frame 3.The contact point device 70 includes a first contact portion 761 and a second contact portion 762. In the present embodiment, the first contact portion 761 is provided on the second contact device 72, and the second contact portion 762 is provided on the first contact device 71.The first contact portion 761 is formed in a protruding shape protruding from the opposing surface 721 of the disk-shaped second contact device 72 toward the first contact device 71. Specifically, in the present embodiment, the outer surface of the first contact portion 761 facing the second contact portion 762 has a cylindrical side surface, a substantially circular shaped top surface, and a curved surface between the side surface and the top surface, such as a spherical surface shape or a conical surface shape.In the present embodiment, a plurality of first contact portions 761 are provided so as to face the corresponding first contact devices 71. Namely, a first group of the first contact portions 761 corresponding to one of the pair of the first contact devices 71 is disposed on one end of the second contact device 72 in the widthwise direction. A second group of the first contact portions 761 corresponding to the other of the pair of the first contact devices 71 is disposed on the other end of the second contact device 72 in the widthwise direction.FIG. 4 is an enlarged view showing a group of first contact portions 761 provided corresponding to one of the pair of first contact devices 71. As shown in FIG. 4, the group of first contact portions 761 is arranged at equal intervals on the periphery CF so as to surround the central axis RA. More specifically, the group of first contact portions 761 is arranged such that the centers are arranged at equal intervals in the circumferential direction on the periphery CF in plan view. In addition, in the present embodiment, three first contact portions 761 are provided on a periphery CF. The periphery CF is a curve substantially perpendicular to the central axis RA on the opposing surface 721 and corresponds to a circle formed around the intersection of the central axis RA and the opposing surface 721.The second contact portion 762 is provided at the distal end portion 712 of each of the pair of first contact devices 71. As can be seen from FIGS. 2, 3 to 4, the second contact portion 762 protrudes in the coil axis direction toward the virtual space VS surrounded by the plurality of first contact portions 761.The second contact portion 762 has a contact surface 763. The contact surface 763 is a convexly curved surface exposed to the virtual space VS and formed to surround the central axis RA. Specifically, in the present embodiment, the entire contact surface 763 is formed in a substantially spherical shape.(Operation and Effect of Embodiment)Hereinafter, with reference to FIGS. 1, 2, 3 to 4, the operation and effect obtained by the present embodiment will be described.When the energization of the coil 4 is interrupted, the movable core 61 is separated from the fixed core 51 by the urging force of the return spring 64 in the return direction. As a result, the movable shaft 62 integrated with the movable core 61 moves in the return direction.When the movable shaft 62 moves in the return direction, the insulator 63 fixed to the tip end of the movable shaft 62 abuts against the second contact device 72 at a position between the first contact portions 761. Then, when the movable shaft 62 further moves in the return direction, the second contact device 72 moves in the return direction against the biasing force of the contact pressure spring 74. As a result, as shown in FIG. 1, the first contact portion 761 and the second contact portion 762 are separated from each other, and energization therebetween is interrupted.When energizing the coil 4, the movable core 61 is attracted to the fixed core 51 by the magnetic field generated by the coil 4. Then, the movable core 61 moves in the suction direction to a position near the fixed core 51 against the urging force of the return spring 64.When the movable core 61 moves in the suction direction, the movable shaft 62 and the movable insulator 63 also move in the suction direction. Then, by the urging force of the contact pressure spring 74 in the suction direction, the second contact device 72 moves in the suction direction to approach the first contact device 71.The second contact portion 762 provided on the distal end portion 712 of the first contact device 71 and the first contact portion 761 provided on the opposing surface 721 of the second contact device 72 abut each other, whereby the first contact device 71 and the second contact device 72 are electrically connected. Namely, a flow path is formed from the one of the pair of first contact devices 71 to the other of the pair of first contact devices 71 via the second contact device 72.In the present embodiment, the second contact portion 762 provided at the distal end portion 712 of the first contact device 71 advances into the virtual space VS. As a result, the contact surface 763, which is a curved surface provided on the second contact portion 762 to surround the central axis RA of the first contact device 71, is in contact with the outer surfaces of the first contact portions 761 facing the virtual space VS.At this time, the first contact device 71 is supported by the oscillation supporting portion 73 so as to be able to oscillate. Therefore, the contact surface 763, which is a curved surface, of the second contact portion 762 provided to the virtual space VS on the distal end portion 712 of the first contact device 71 suitably abuts all the contact portions 761 facing the virtual space VS.Due to manufacturing errors or the like, there is a possibility that the central axis RA of the first contact device 71 does not pass through the center of the periphery CF on which the group of first contact portions 761 is provided when the energy of the coil 4 is lowered. Alternatively, for example, due to manufacturing errors or the like, one of the first contact portions 761 may have a size of protrusion in the coil axis direction or the outer diameter smaller than the others.In this regard, according to the present embodiment, the central axis RA of the first contact device 71 oscillates moderately due to the force applied to the first contact device 71 when the first contact portion 761 and the second compact portion 762 are brought into contact with each other. This oscillation can be a three-dimensional oscillation such as, for example, a gyroscopic movement, in particular a conical gyroscopic movement. Therefore, even in the above-described case, the second contact portion 762 provided at the distal end portion 712 of the first direction 71 can sufficiently abut on all of the corresponding group of the first contact portions 761.As described above, according to the present embodiment, the second contact portion 762 and the plurality of first contact portions 761 are in contact in a stable manner in the region where the first contact device 71 and the second contact device 72 come close to and face each other. Therefore, the contact resistance between the first contact device 71 and the second contact device 72 is satisfactorily reduced. Namely, according to the present embodiment, it is possible to satisfactorily reduce the contact resistance during energization without lowering the reliability which may be caused by the change in the material of the contact member or without an increase in the size of the apparatus which may be caused by the increase in the contact pressure.In addition, since the first contact device 71 is supported to oscillate, accurate parallelism between the normal line of the opposing surface 721 and the central axis RA is not required. The accuracy is also not required in the positional relationship relative to the center of the circumference CF. Therefore, according to the present embodiment, the design can be made flexible for the electromagnetic relay 1 and the contact point device 70.(Modifications)The present disclosure is not limited to the specific examples described in the above-described embodiment. Namely, it is possible to suitably change the above-described embodiment. Representative modifications are described below. In the following description of the variation examples, only the features different from those of the above-described embodiments will be explained. In addition, in the above-described embodiments and the modifications, the same reference numerals are assigned in the same or equivalent parts. Therefore, in the description of the following modifications regarding the components having the same reference numerals as the components of the above-described embodiment, the description in the above-described embodiment can be appropriately recited as long as there is no technical contradiction or a certain additional explanation here.As described above, the electromagnetic relay 1 and the contact point device 70 according to the present disclosure have the plunger structure, and can sufficiently cope with an increase in system output in the electric vehicle. However, the electromagnetic relay 1 and the contact point device 70 according to the present disclosure are not limited to being applied to the power transmission path between the motor drive circuit and the battery in the electric vehicle. Namely, the electromagnetic relay 1 and the contact point device 70 are not limited to being mounted on a vehicle. Moreover, the electromagnetic relay 1 is not limited to the plunger type.The present disclosure is not limited to the specific examples described in the above-described embodiment. For example, the configurations of the fixed portion 5 and the movable portion 6 are not limited to the specific examples described above.For example, the shapes of the fixed core 51, the movable core 61, and the like may be appropriately changed from the shapes shown in FIG. 1. Specifically, for example, the movable core 61 may be fixed to an end portion of the movable shaft 62 in the suction direction. In this case, the fixed core 51 has no function of guiding the reciprocating motion of the movable shaft 62. Namely, in this case, the guide hole 52 is not formed in the fixed core 51.The shape of the first contact device 71 is not limited to the specific example described above. For example, the first contact device 71 may be formed in a shape of a tube having a through hole along the central axis RA. In addition, a groove portion may be formed instead of the flange portion 714. Alternatively, a portion of the first contact device 71 other than the distal end portion 712 may be formed into a polygonal prism shape. In this case, the flange portion 714 or the groove portion for replacing the flange portion 714 may be omitted by providing the oscillation supporting portion 73 to bridge the polygonal prism portion and the pillar portion.The oscillation manner of the oscillation supporting portion 73 supporting the first contact device 71 is not limited to the specific example described above. For example, the oscillation supporting portion 73 may be provided to expose the intermediate portion 713 while the end portion of the first contact device 71 opposite to the distal end portion 712 is covered. Alternatively, the oscillation supporting portion 73 may be provided to cover substantially the entirety (namely, a portion other than the distal end portion 712) of the outer side surface 711 of the first contact device 71.Also, there is no particular limitation on the shape and structure of the oscillation supporting portion 73. namely, the outer shape of the oscillation supporting portion 73 may be substantially a cylindrical shape as shown in FIG. 2, or may be a shape of a polygonal prism. In addition, the oscillation supporting portion 73 may have a member other than the elastic member. For example, the oscillation supporting portion 73 may include an elastic member covering the outer side surface 711 of the first contact device 71 and a tubular rigid member covering the outermost edge surface of the elastic member.The entirety of the outer surface of the first contact portion 761 facing the second contact portion 762 may be formed in a partially spherical shape. Alternatively, a portion of the first contact portion 761 that does not contact the second contact portion 762 may be omitted, as appropriate. Namely, for example, the first contact portion 761 may be formed in a partial columnar shape of a semicircular columnar shape. The contact surface 763 of the second contact portion 762 may have a cylindrical side surface surrounding the central axis RA, a top surface substantially circular shaped, and an annular part spherical surface or a conical curved surface provided to surround the central axis RA, between the cylindrical side surface and the top surface.The first contact portion 761 is not limited to the protrusion protruding from the opposing surface 721 of the second contact device 72 along the coil axis direction. Such modifications will be described below.As can be seen from FIGS. 5 and 6, the first contact portion 761 may be a protrusion protruding to the center of a contact forming hole 771 penetrating the second contact jig 72 in the thickness direction. Such protrusions may be formed in a partial pillar shape (for example, a semicircular pillar shape) having an axial direction parallel to the thickness direction of the second contactor 72.The first contact portions 761 are arranged at equal intervals on the circumference CF. In this case, the periphery CF corresponds to a periphery forming an inner periphery of a circular bore, assuming that the contact forming bore 771 is formed such that the first contact portions 761 protrude from the inner peripheral surface of the circular bore. Also, in this modification, three first contact portions 761 are provided on a periphery CF. The three first contact portions 761 are formed to surround the central axis RA on the opposing surface 721 or the back surface 722 of the second contact device 72.In such a configuration, the second contact portion 762 formed at the distal end portion 712 of the first contact device 71 penetrates the opening formed through the contact forming bore 771. Then, the contact surface 763, which is a curved surface exposed to the contact formation hole 771 at the distal end portion 712 of the first contact piece 71, contacts all of the plurality of first contact portions 761 facing the contact formation hole 771. The same effects as those of the above-described embodiment can be obtained with this structure.As described above, the above-mentioned protrusion forming the first contact portion 761 may have a half-cylindrical shape or may not have a half-cylindrical shape. In the former case, the central axis of the cylindrical surface of the protrusion is disposed on the circumference CF. In the latter case, the central axis of the cylindrical surface of the protrusion is not disposed on the circumference CF.In FIGS. 5 and 6, the contact formation hole 771 may not be a through hole. Namely, the contact forming hole 771 may have a recessed portion closed on the back surface 722. In addition, the inner side of the periphery CF may be formed in a concave shape on the opposing surface 721.As can be seen from FIGS. 7, 8 to 9, a plurality of first contact portions 761 may be provided on the distal end portion 712 of the first contact device 71, while the second contact portion 762 may be provided on the second contact device 72. The same effects as those of the above-described embodiment can be obtained with this structure.In this case, the first contact portion 761 protrudes from the end surface 781 of the first contact device 71 adjacent to the distal end portion 712 along the central axis RA. Namely, the plurality of first contact portions 761 are provided to surround the central axis RA on the end surface 781, which is a plane perpendicular to the central axis RA.The first contact portion 761 is provided as a columnar protrusion formed by connecting two part cylindrical surfaces whose respective generatrixes are parallel to the central axis RA and project in opposite directions. One of the two part-cylindrical surfaces forming the outer side surfaces of the first contact portion 761 is formed to be continuous with the outer side surface 711 of the intermediate portion 713. Namely, the part-cylindrical surface is provided to define a part of the cylindrical outer side surface 711 of the first contact device 71.In this modification, three first contact portions 761 are also provided at equal intervals on a periphery CF. In this case, as shown in FIG. 9, the periphery CF corresponds to the outer shape of the first contact device 71 in a plan view. In addition, the second contact portion 762 protrudes in the coil axis direction from the opposing surface 721 of the second contact device 72 to the virtual space VS surrounded by a pair (i.e., three) of the first contact portions 761.As can be seen from FIG. 10, the first contact device 71 can be provided on the movable portion 6, while the second contact device 72 can be provided on the fixed portion 5. The same effects as those of the above-described embodiment can be obtained with this structure.Specifically, in this modification, the first contact device 71 is attached to a movable plate 791 via the oscillation supporting portion 73. Like the second contact device 72 in the above-described embodiment, the movable plate 791 is a conductive contact member made of a conductive metal and formed substantially in a flat plate shape having a thickness direction parallel to the coil axis direction.In this modification, one and the other of the pair of first contact devices 71 arranged in the widthwise direction are also arranged substantially symmetrically with respect to the coil axis LA. Each of the first contact devices 71 is electrically connected to the movable plate 791 via a wiring portion (not shown).The second contact device 72 is fixed to the protrusion of the frame 3. In this modification, a pair of the second contact devices 72 is provided corresponding to the pair of the first contact devices 71. When the coil 4 is not energized, the pair of second contact devices 72 are electrically insulated from each other by the frame 3 in a state where the first contact device 71 is separated from the second contact device 72.FIG. 10 shows an example in which a plurality of first contact portions 761 are provided on the second contactor 72, and a second contact portion 762 is provided on the first contactor 71, similar to the above-described embodiment. Namely, in FIG. 10, each of the second contact devices 72 has a plurality of first contact portions 761. The detailed structure of the contact point device 70 in FIG. 10 is the same as that shown in FIGS. 2, 3 to 4, except that the second contact device 72 is divided into two.In FIG. 10, the oscillation supporting portion 73 may be formed of a conductive material. Namely, the pair of first contact devices 71 may be electrically connected to each other via the oscillation supporting portion 73 and the movable plate 791. In addition, modifications corresponding to FIGS. 5 and 6 and modifications corresponding to FIGS. 7, 8 to 9 may be applied to the modification shown in FIG. 10.Two first contact portions 761 may be provided on a periphery CF. Alternatively, four or more first contact portions 761 may be provided on a periphery CF. In a case where three or more first contact portions are provided on a periphery CF, the first contact portions 761 may be arranged in equal or non-equal portions on the periphery CF.In the above description, the seamless integrally formed member may be configured to have a seam due to adhesion among plural members or the like. Similarly, the plurality of separately provided members may be integrally and seamlessly joined to each other. There is no particular limitation on the material constituting each member.The modifications are not limited to the description given above. Warmer modifications may be combined with each other. Moreover, some of the configurations in the above-described embodiment and some configurations in each of the above-described modifications may be combined with each other.

Claims

A contact point apparatus configured to switch an electric current to flow or not by relative movement between a movable portion (6) and a fixed portion (5), the contact point apparatus comprising: a first contact device (71) provided on one of the movable portion (6) and the fixed portion (5) as a conductive contact member having an outer side surface (711) shaped in a shape of a column surrounding a center axis along a relative movement direction of the movable portion (6) and the fixed portion (5); an oscillation supporting portion (73) supporting the first contact device (71) on the one of the movable portion (6) and the fixed portion (5) to allow the center axis to oscillate; and a second contact device (72), which is provided on the other of the movable portion (6) and the fixed portion (5) as a conductive contact member provided opposite to the first contact device (71) in the relative moving direction to be electrically connected to the first contact device (71) by abutting against the first contact device (71), one of the first contact device (71) and the second contact device (72) having a plurality of first contact portions (761) provided to surround the central axis on a plane perpendicular to the central axis, the other of the first contact device (71) and the second contact device (72) having a second contact portion (762) provided to project in the relative moving direction to a space surrounded by the plurality of first contact portions (761), and the second contact portion (762) has a contact surface (763) that is a curved surface exposed to the space to surround the central axis.The contact point device according to claim 1, wherein the plurality of first contact portions (761) comprises: three of the first contact portions (761) equally spaced from each other on a circumference surrounding the central axis.The contact point apparatus according to claim 1 or 2, wherein the oscillation supporting portion (73) has an elastic member in close contact with the outer side surface (711) of the first contact device (71).The contact point apparatus according to any one of claims 1 to 3, wherein the first contact device (71) is attached to the fixed portion (5) through the oscillation supporting portion (73), and the second contact device (72) is provided on the movable portion (6).The contact point apparatus according to any one of claims 1 to 4, wherein the plurality of first contact portions (761) are provided on the second contact device (72), and the second contact portion (762) is provided on a tip end portion of the first contact device (71).The contact point apparatus according to claim 5, wherein the second contact device (72) has a shape of a disk, and the first contact portion (761) has a protruding shape protruding from the second contact device (72) toward the first contact device (71).The contact point apparatus according to any one of claims 1 to 4, wherein the plurality of first contact portions (761) are provided at a tip end portion of the first contact device (71), and the second contact portion (762) is provided on the second contact device (72).An electromagnetic relay configured to switch an electric current to flow or not by relative movement in a coil axis direction based on a energization state of a coil, the electromagnetic relay comprising: a first contact device (71) provided on one of the movable portion (6) and the fixed portion (5) as a conductive contact member having an outer side surface (711) shaped in a shape of a column surrounding a center axis along the coil axis direction; an oscillation supporting portion (73) supporting the first contact device (71) on the one of the movable portion (6) and the fixed portion (5) to allow the center axis to oscillate; a second contact device (72), which is provided on the other of the movable portion (6) and the fixed portion (5) as a conductive contact member provided opposite to the first contact device (71) in the coil axis direction to be electrically connected to the first contact device (71) by abutting against the first contact device (71), one of the first contact device (71) and the second contact device (72) having a plurality of first contact portions (761) provided to surround the center axis on a plane perpendicular to the center axis, the other of the first contact device (71) and the second contact device (72) having a second contact portion (762) provided to protrude in the coil axis direction to a space surrounded by the plurality of first contact portions (761), and the second contact portion (762) has a contact surface (763) that is a curved surface exposed to the space to surround the central axis.The electromagnetic relay according to claim 8, wherein the plurality of first contact portions (761) comprises: three of the first contact portions (761) equally spaced from each other on a circumference surrounding the central axis.The electromagnetic relay according to claim 8 or 9, wherein the oscillation assisting portion (73) has an elastic member in close contact with the outer side surface (711) of the first contact device (71).The electromagnetic relay according to any one of claims 8 to 10, wherein the first contact device (71) is attached to the fixed portion (5) through the oscillation supporting portion (73), the second contact device (72) is provided on the movable portion (6).The electromagnetic relay according to any one of claims 8 to 11, wherein the plurality of first contact portions (761) are provided on the second contact device (72), and the second contact portion (762) is provided on a tip end portion of the first contact device (71).The electromagnetic relay according to claim 12, wherein the second contact device (72) has a shape of a disk, and the first contact portion (761) has a protruding shape protruding from the second contact device (72) toward the first contact device (71).The electromagnetic relay according to any one of claims 8 to 11, wherein the plurality of first contact portions (761) are provided at a tip end portion of the first contact device (71), and the second contact portion (762) is provided on the second contact device (72).The electromagnetic relay according to any one of claims 8 to 14, wherein the first contact device (71) is one of a pair of first contact devices (71, 71) arranged in a widthwise direction perpendicular to the coil axis direction to be electrically insulated from each other in a state separated from the second contact device (72), and the second contact device (72) is arranged across the pair of first contact devices (71, 71) in the widthwise direction to electrically connect the pair of first contact devices (71) to each other by making contact with the pair of first contact devices (71, 71).

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