This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2018-225916, filed Nov. 30, 2018, the entire contents of which are incorporated herein by reference.
The present invention relates to a terminal and a relay.
Relays (electromagnetic relays), in which contacts are opened and closed by an electromagnet, comprise an electromagnet, an armature, a movable terminal including a movable contact, and a fixed terminal including a fixed contact. In such relays, the armature is moved by the excitation of the electromagnet, whereby the armature is pressed against the movable terminal, and contact between the movable contact and the fixed contact come is established.
JP 5741679 B discloses a relay comprising a terminal in which a first member including a movable contact and a second member including a leg are affixed thereto by crimping in three locations.
JP 3959894 B discloses a relay in which an insulated pressing member, which presses a movable terminal, is attached to an armature to secure the insulation distance between the movable terminal and the armature.
JP 2008-053152 A discloses a relay in which an electromagnet and an armature are surrounded with an insulating wall, so as to secure the insulation distance for a movable terminal and a fixed terminal.
In relays comprising a terminal in which two members are affixed in a plurality of locations, when outside forces are applied to the terminal, there is a risk that the locations of fixation between the members could become damaged due to non-uniform stress concentration.
An aspect of the present invention provides a terminal of a relay comprising a first member having a leg, and a second member combined with the first member and having a contact, wherein the second member has at least three holes, the first member has at least three protrusions which are individually inserted into and crimped in the at least three holes, and an intermediate hole among the at least three holes is arranged so as to be positioned on the side opposite the contact with respect to a straight line that contacts the edges of the outermost holes on the side close to the contact.
According to the terminal of the aspect, when a force is applied to the pressing location, the difference between the stress concentrated around a single hole and the stress concentrated around the holes adjacent thereto is reduced, and the stress is uniformly distributed to prevent deformation of the second member.
The relays according to the embodiments will be described below with reference to the attached drawings.
The constituent parts assembled in the base 4 include a movable terminal 20, a fixed terminal 26, an electromagnet 7, a hinge spring 8, an armature 10, and a pressing member 12 made of a resin or the like.
The movable terminal 20 comprises a first member 14 including two legs 14a, 14b, and a second member 18 including a movable contact 16. The fixed terminal 26 comprises two legs 22a, 22b, and a fixed contact 24. The electromagnet 7 comprises a coil assembly 27, an iron core 30, and a yoke 32. The coil assembly 27 comprises two coil terminals 28 comprising respective legs 28a, 28b, a coil 34 which is connected to the coil terminals 28, and a bobbin 36 on which the coil 34 is wound.
The electromagnet 7 is excited by applying a voltage to the terminals 28. Due to the excitation of the electromagnet 7, the armature 10 pivots and contacts the iron core 30. The pressing part 12 attached to the armature 10 presses the movable terminal 20 in accordance with the pivoting of the armature 10, and the movable contact 16 comes into contact with the fixed contact 24. The hinge spring 8 is attached to the armature 10 and the yoke 32, and biases the armature 10 in a direction away from the iron core 30.
When the application of voltage to the coil terminal 28 is stopped, the armature 10 returns to a position spaced from the iron core 30 by the biasing of the hinge spring 8. Then, the pressing force from the pressing part 12 to the movable terminal 20 is released as the armature 10 returns, and the movable contact 16 separates from the fixed contact 24.
The movable contact 16 and the fixed contact 24 open and close with the above configuration. The aforementioned configuration is merely exemplary, and any configuration may be used. For example, the fixed terminal 26 may comprise a member including the contact 24, and a member including the legs 22a, 22b.
The first member 14 comprises legs 14a, 14b for electrical connection with external components, and a plurality (three in the drawings) of protrusions 36a, 36b, and 36c (collectively “protrusions 36”). The second member 18 comprises the contact 16, and a plurality (three in the drawings) of holes 38a, 38b, and 38c (collectively “holes 38”). The second member 18 is a plate-like member which is elastically displaceable. The first member 14 and the second member 18 are made of, for example, a metal.
The protrusions 36 are individually inserted into the corresponding holes 38 and the tips thereof are crimped to formed crimped parts 40a, 40b, and 40c (collectively “crimped parts 40”).
The first member 14 and the second member 18 are electrically connected and mutually affixed by the crimped parts 40. Though a voltage drop occurs when current flows through the movable terminal 20, the internal resistance of the movable terminal 20 is reduced by providing crimped parts 40, so as to reduce the voltage drop. If high current of 30 A or more flows, it is preferable that three or more crimped parts 30 be provided.
The three crimped parts 40 shown in
The holes 38 may be circular, elliptical, triangular, or rectangular, and the protrusions may be shaped so as to be capable of being inserted into the respective holes.
A pressed part 42a is an area which is pressed by the pressing member 12. The stress in the vicinity of the holes 38′ will be described using the center point 44a of the pressing part 42a. The center 44a is arranged in the geometrical center of the second member 19, and the force with which the pressing member 12 presses the second member 19 will be assumed as being received at a single point.
The magnitude of the stress occurring around the holes 38′ due to the force applied to the center 44a depends on the distance from the center 44a. As the distance between the center 44a and the holes 38′ decreases, the bending angle in the vicinity of the hole of the second member 19 increases and the stress increases.
In
Conversely, a line L33 connecting the center 44a and the center 39e of the hole 38e is shorter than the lines L11 and L22. In
Under such a positional relationship, the stress around the hole 38e is greater than the stresses around the holes 38d and 38f.
The center hole 38b is arranged lower than the holes 38a and 38c. A line L10 contacts edges 46 and 50 on the contact 16 side of the holes 38a, 38c. When the holes 38a and 38c are circular, the line L10 is tangent to the circles.
The hole 38b is arranged on the side opposite the contact 16b with respect to the line L10.
A line L1 connecting the center 44 and the center 39a of the hole 38a and a line L2 connecting the center 44 and the center 39c of the hole 38c have substantially the same lengths.
The hole 38b is arranged lower than the holes 38a and 38c, and the hole 38b is arranged on the side opposite the contact 16 with respect to the line L10.
In the present embodiment, a line L3 connecting the center 44 and the center 39b of the hole 38b is longer than the line L33 of
By arranging the hole 38b in a position which minimizes the difference between the lengths of the lines L1 and L2 and the length of the line L3, when a force is applied to the pressing location 42, the difference between the stress around one hole and the stresses around the other holes is minimized, and by uniformly distributing the stress, deformation of the second member 18 can be prevented.
The centers 39a, 39b, and 39c of the holes 38a, 38b, and 38c are arranged on the same line, the edge of the hole 38b on the contact 16 side is lower than those of the holes 38a and 38c.
A line L10 contacts edges 46, 50 of the holes 38a, 38c on the contact 16 side. The hole 38b is arranged so as to be positioned on the side opposite the contact 16 with respect to the line L10.
A line L1 connecting the center 44 and the center 39a and a line L2 connecting the center 44 and the center 39c have substantially the same lengths.
When the hole 38b is arranged lower than the holes 38a and 38c, the hole 38b is arranged on the side opposite the contact 16 with respect to the line L10. The length of a line L3 connecting the center 44 and the center 39b is longer than that of the line L33 in
By arranging the hole 38b in a position in which the difference between the lengths of the lines L1 and L2 and the length of the line L3 is minimized, when a force is applied to the pressing location 42, the difference between the stress around a single hole and the stress around the other holes is reduced, and by uniformly distributing the stress, deformation of the second member 18B can be prevented.
The movable terminal 20B is designed so as to minimize the difference between the lengths of the line L3 and the lines L1 and L2 by reducing the diameter of the hole 38b. Thus, since the lower end of the hole 38b is arranged higher as compared with the case shown in
The crimped parts 40 can also be applied to the fixed terminal 26 comprising the first member including the contact 24 and the second member including the legs 22a and 22b.
Though the movable terminals 20 and 20B having three crimped parts 40 have been described, a terminal may have four or more crimped parts as long as the second member has at least three holes, and the edge of an intermediate hole on the contact side is arranged so as to be positioned on the side opposite the contact with respect to a line which contacts the edges of the outermost holes.
When high current is flowed through the terminal, reducing internal resistance may be reduced by increasing the sizes of the legs. When a terminal such as a blade terminal is used in order to increase the size of the legs, it is necessary to form square holes in the substrate to which the legs are connected.
Conversely, when internal resistance is reduced by providing a plurality of comparatively small legs, such as legs 14a and 14b shown in
The first member 14 comprises a support 56 having a flat surface 56a. Three protrusions 36 are formed on the surface 56a. As shown in
By contacting the surface 56a to a surface 18a on which the contact 16 is provided, the surface 56a can absorb the force imparted to the second member 18 which is pressed by the pressing member 12.
If the first member is arranged on a side opposite the position shown in
Conversely, in the present embodiment, the first member 14 is arranged on the side of the second member 18 that is pressed by the pressing part 12, and the lower part of the second member 18 is supported by the straight upper end 56b of the surface 56a. Therefore, the range across which the second member 18 is supported is widened. Further, as the upper end 56b supporting the second member 18 is separated from the crimped parts 40 by a certain distance, the stresses generated in the second member 18 in the vicinity of the crimped parts 40 can be distributed, and concentration of stress in the crimped parts 40 can be prevented. Thus, the stresses around the holes 38 when the second member 18 is pressed toward the first member 14 are reduced as compared to the case in which the support 56 is not provided.
The legs 14a and 14b will be described using
The leg 14a comprises an end 60a which is bent away from the base 58a. The end 60a is formed so that the bottom thereof extends in a direction away from the second member 18. The base 58a is bent so that the portion thereof which connects with the end 60a is arranged above the portion thereof which connects with the support 56. The leg 14b is configured in the same manner as the leg 14a, and comprises a base 58b and an end 60b.
The base 4 houses the movable terminal 20 and the fixed terminal 26, and comprises a bottom 61 to which an adhesive 71 such as an epoxy resin is applied. The bottom 61 comprises a first adhesion part 62 having a hole 64 from which the end 60a of the leg 14a protrudes outside.
By applying the adhesive 71 to the surface 62a outside the first adhesion part 62 and occluding the hole 64, the intrusion of foreign matter such as solder or flux into the interior of the relay 2 can be prevented.
The bottom 61 comprises a second adhesion part 70 including a hole 72 from which the leg 22a protrudes outside. The adhesive 71 is applied to the surface 70a of the second adhesion part 70 to occlude the hole 72. The surface 62a and the surface 70a are arranged on the same plane. In order to ensure space for applying the adhesive 71, the surface 62a and the surface 70a are arranged above the lower end 6a of the cover 6.
The bottom 61 includes a raised part 66. The raised part 66 includes a recess 68 and bulges downward in
The base 58a is housed within the recess 68. The end 60b is arranged outside the recess 68, and protrudes from the hole 64. The end 60b does not protrude to the outside of the relay 2 from below the crimped part 40b. Regarding the unillustrated leg 14b, the base 58b thereof is also housed within the recess 60, and the first adhesion part 62 has an unillustrated hole from which the end 60b of the leg 14b protrudes. The adhesive 71 is applied to the hole.
By housing the bases 58a, 58b in the recess 68, and arranging the ends 60a, 60b so as to protrude to the outside of the relay 2 at positions separated from the crimped parts 40, it is not necessary to ensure space below the crimped parts 40 for applying the adhesive 71, whereby the accommodation space of the second member 18 can be expanded by the height of the recess 68. Thus, the second member 18 can be lengthened to increase the allowable current while maintaining the low profile of the relay 2.
The iron core 30 is arranged below the first portion 74 as shown in
The armature 10 pivots about an axis 80, correspond to the position of the bent part 78, while deforming the hinge spring 8. When the first portion 74 moves in direction B, the second portion 76 moves in direction A, whereby the pressing part 12 presses the movable terminal 20. The movable terminal 20 is displaced in accordance with the movement of the armature 10.
The pressing member 12 comprises a receiving part 88 which receives the insertion 82 in an enclosure 90 one end of which is open. The receiving part 88 has four inner surfaces 88a, 88b, 88c, and 88d, a bottom surface 88e, and an aperture 91 positioned on the side opposite the bottom surface 88e.
When the pressing member 12 is attached to the armature 10, the insertion 82 is inserted into the receiving part 88. By guiding the insertion 92 along the groove 84, the pressing member 12 is attached to the armature 10 along direction C which is parallel to the axis 80.
In order to facilitate insertion of the insertion 82 into the receiving part 88, tapered guide surfaces 93, 95 are formed on the portion of the surface 88d close to the aperture 91, and on the tip of the insertion part 82, respectively. When the insertion 82 is fully received in the receiving part 88, the receiving part 88 covers the insertion 82 with the enclosure 90.
By inserting the insertion 82 into the receiving part 88 in direction C and attaching the pressing member 12 to the armature 10 by inserting the insertion 92 into the groove 84, the pressing member is not misaligned in the vertical directions relative to the armature 10. Thus, even if misalignment of the armature 10 and the pressing member 12 occurs, the direction thereof is limited to the direction parallel to the axis 80 along the groove 84.
Thus, in the relay 2, even if the position of the pressing member 12 is displaced relative to the armature 10 due to impact or the like, the distance L21 does not change since the direction of displacement is limited to the direction parallel to the axis 80. As long as the distance L21 does not change, the position in the vertical direction at which the pressing member 12 presses the movable terminal 20 does not change, and thus, the moment of the pressing force imparted to the movable terminal 20 from the pressing member 12 does not change. Thus, it is not necessary to change the voltage applied to the coil 34 to bring the first portion 74 of the armature 10 into contact with the iron core 30, and changes in the characteristics of the relay 2 such as operating voltage can be prevented.
The enclosure 90 covers the insertion 82 to insulate the armature 10 and the movable terminal 20 from each other. Further, a pressing part 86 protruding toward the movable terminal 20 is provided outside the enclosure 90. Therefore, the armature 10 and the movable terminal 20 are arranged in positions which are spaced from the left and right directions of
As shown in
The first protrusion 94 has a shape which protrudes in a straight line extending in the direction parallel to the inner surfaces 88a, 88c from the vicinity of the aperture 91 to the bottom surface 88e. When the pressing member 12 is attached to the armature 10, the first protrusion 94 is arranged parallel to the axis 80.
The first protrusion 94 includes a high part 94a and a low part 94b which differ in height from the inner surface 88b. The high part 94a is formed on the side close to the bottom surface 88e, and the low part 94b, which is shorter in height from the inner surface 88b than the high part 94a, is formed on the side close to the aperture 91.
When the insertion 82 is inserted into the receiving part 88 in direction C to attach the pressing member 12 to the armature 10, the end surface 98 slides on the first protrusion 94. As the insertion 82 is pushed into the receiving part 88, the end surface 98a engages so as to be wedged into the high part 94a after passing through the low back part 94b, and the end surface 98b engages so as to be wedged into the low part 94b.
The first protrusion 94 positions the pressing member 12 relative to the longitudinal direction of the armature 10. By engaging the end surface 98 with the first protrusion 94, the other edge 99 of the insertion 82 is pressed against the inner surface 88d. As a result, the insertion 82 is inserted into and press-fit in the receiving part 88, whereby misalignment of the armature 10 and the pressing member 12 in the vertical direction is prevented.
Furthermore, the end surfaces 98a, 98b engage with the high part 94a and the low part 94b at two points. Therefore, inclination of the insertion 82 relative to the pressing member 12 toward the direction in which the degree of parallel alignment between the end surface 98 and the inner surface 88b is deteriorated can be prevented. As a result, a high level of parallel alignment between the tip 86a and the axis 80 can be secured.
The pressing member 12 comprises a second protrusion 96 which engages with a surface 100 of the insertion 82.
The second protrusion 96 has a shape which extends from the vicinity of the aperture 91 to the bottom surface 88e in a straight line extending in the direction parallel to the inner surfaces 88b, 88d. When the pressing member 12 is attached to the armature 10, the second protrusion 96 is arranged parallel to the axis 80.
The second protrusion 96 has a high part 96a and a low part 96b which differ in height from the inner surface 88c. The high part 96a is formed on the side close to the bottom surface 88e, and the low part 96b, which is shorter than the high part 94a, is formed on the side close to the aperture 91.
The armature 10 has a surface 100 and an end surface 106. The surface 100 has a back-side 100a distant from the end surface 106, and a front side 100b close to the end surface 106. The back-side 100a has a recess 102 which is parallel to the axis 80, and a stepped shape is formed on the surface 100 by the recess 102. The surface 100 engages with the high part 96a in the recess 102, and engages with the low part 96b on the front side 100b.
When the insertion 82 is inserted into the receiving part 88 in direction C to attach the pressing member 12 to the armature 10, the surface 100 slides on the protrusion 96. As the insertion 82 is pressed into the receiving part 88, the recess 102 passes the low part 96b and then engages with the high part 96a, and the front side 100b engages with the low part 96b.
The second protrusion 96 positions the pressing member 12 relative to the direction in which the second portion 76 moves. By engaging the surface 100 with the second protrusion 96, the surface 100 is pressed against the inner surface 88a. As a result, the insertion 82 is inserted into and press-fit in the receiving part 88, whereby misalignment of the armature 10 and the pressing member 12 in direction A is prevented.
Since the surface 100 of the insertion 82 engages with the high part 96a and the low part 96b at two points, the recess 102 and the front side 100b, inclination of the insertion 82 relative to the pressing member 12 toward the direction in which the degree of parallel alignment between the surface 100 and the inner surface 88c is deteriorated can be prevented. As a result, a high level of parallel alignment between the tip 86a and the axis 80 can be secured.
The end surface 98 and the surface 100 may not have a stepped shape. The first protrusion 94 may be shaped so as to have a constant height without forming the high part 94a and the low part 94b. Likewise, the second protrusion 96 may be formed so as to have a constant height without forming the high part 96a and the low part 96b.
In this case, by engaging the end surface 98 with the first protrusion 94, the other edge 99 is pressed against the inner surface 88d. As a result, the insertion 82 can be inserted into and press-fit in the receiving part 88, and misalignment between the armature 10 and the pressing member 12 in the vertical directions is prevented.
Further, by engaging the surface 100 with the second protrusion 96, the surface 101 is pressed against the inner surface 88a. As a result, the insertion 82 can be inserted into and press-fit in the receiving part 88, and misalignment between the armature 10 and the pressing member 12 in direction A is prevented.
The crimped part 104 is deformed by applying heat.
The deformed crimped part 104 shown in
The insulation structure of the relay 2 will be described with reference to
The relay 2 comprises a first area 110 in which the coil 34 and the iron core 30 are arranged, and a second area 112 in which the movable terminal 20, the fixed terminal 26, and the pressing member 12 are arranged. The base 4 includes a wall 108 which is positioned between the first area 110 and the second area 112 and which extends in the upwards and downwards directions.
The wall 108 is formed from, for example, a resin, and insulates the coil 34 from the movable terminal 20 and the fixed terminal 26. Since the wall 108 is formed so as to separate the first area 110 and the second area 112 and so as to cover the portion of the coil 34 in the vicinity of the second area 112, the insulation distance between the coil 34 and the movable terminal 20 and the fixed terminal 26 can be maintained.
The first portion 74 is arranged in the first area 110 above the coil 34 and the iron core 30. The second portion 76 is arranged in the second area 112 extending from the first portion 74.
Since the pressing member 12 is attached to the second portion 76, the insulation distance between the armature 10 and the movable terminal 20 can be maintained by the pressing member 12.
The bobbin 36 has a first flange 118, a second flange 120, and a cavity 121 into which the iron core 30 is inserted. The bobbin 36 is formed from, for example, a resin. The first flange 118 and the second flange 120 insulate the iron core 30 and the coil 34. Since the first flange 118 and the second flange 120 cover the upper surface 34a and the lower surface 34b of the coil 34, the insulation distance between the iron core 30 and the coil 34 can be maintained.
The base 4 includes a first extending part 114 and a second extending part 116 arranged in the first area 110 which extend from the wall 108. The first extending part 114 is connected to the wall 108, and protrudes toward the first area 110. The second extending part 116 is connected to the wall 108, and protrudes toward the first area 110. The first extending part 114 is opposed to an upper portion of the first flange 118. The second extending part 116 is opposed to a lower portion of the second flange 120. The first extending part 114 and the second extending part 116 insulate the coil 34, the armature 10, and the yoke 32. Since the upper surface 34a is covered by the first extending part 114 and the first flange 118, the insulation distance between the coil 34 and the first portion 74 can be maintained. Likewise, since the lower surface 34b is covered by the second extending part 116 and the second flange 120, the insulation distance between the coil 34 and the first portion 122 can be maintained.
The yoke 32 comprises a first portion 122 arranged in the first area 110, and a second portion 124 arranged in the second area 112 which extends so as to bend away from the first portion 122. The second portion 124 is present along the wall 108, and supports the bend part 78 along the end 126. The wall 108 insulates the second portion 124 and the coil 34. Since the wall 108 covers the coil 34, the insulation distance between the coil 34 and the second portion 124 can be maintained.
By using the bobbin 36 and the base 4 of the present embodiment, the insulation distance between the coil 34 and the other parts can be maintained. Since it is not necessary to provide additional elements for maintaining insulation, an increase of the space within the relay can be prevented, and the insulation properties between the components can be maintained while maintaining the small size of the relay.
The yoke 32 includes an aperture 128 in the first portion 122. The iron core 30 includes a protrusion 130 on an end thereof. By inserting and crimping the protrusion 130 in the aperture 128, the iron core 30 and the yoke 32 are connected to form a magnetic path.
The iron core 30 comprises a shaft 132 which is inserted into the cavity 121, and a head 124 which is arranged outside of the first flange 118. A head 134 includes a surface 134a which extends outwardly from the tip of the shaft 132 on the outside of the coil 34 and which faces outside in the axial direction of the iron core 30. The attractable surface 74a is attracted to the surface 134a by the excitation of the coil 34.
The head 134 includes a surface 134b which projects outwardly from the outer circumference of the shaft 132 on the side opposite the surface 134a. The first extending part 114 extending from the wall 108 has a thin portion 114a at the tip thereof which is inserted between the head 134 and the coil 34, and more specifically, between the surface 134b of the head 134 and the first flange 118.
The assembly of the relay 2 will be described with reference to
An aperture 148 through which the second extending part 116 is exposed is provided in the bottom 61 of the base 4. The second portion 124 is inserted from the aperture 148, and the first portion 122 is arranged outside the second extending part 116. Thereafter, the protrusion 130 protruding from the bobbin 36 is inserted into and crimped in the aperture 128.
As a result, the thin portion 114a is interposed between the surface 134b and the first flange 118, and the second extending part 116 is interposed between the first portion 122 and the second flange 120. Thus, the electromagnet 7 and the base 4 are firmly secured without looseness.
As shown in
By inserting the yoke 32 from the aperture 148, assembly of the relay 2 is simplified, and by covering the bottom 61 with adhesive 71, the relay 2 is sealed so that the intrusion of foreign matter into the interior of the relay 2 can be prevented. Further, the insulation between the relay 2 and external devices is maintained.
The metal part 138 comprises an iron core 140 which is inserted into the cavity 121, and a yoke 142 which extends so as to bend away from the iron core 140. The iron core 140 has a surface 140a outside and above the coil 34. The surface 140a attracts the contact surface 74a by the excitation of the coil 34.
The yoke 142 comprises a first portion 144 arranged in the first area 110 which extends so as to bend away from the iron core 140, and a second portion 146 arranged in the second area 112 which extends away from the first portion 144. The second portion 146 extends along the wall 108, and supports the bent part 78 on the end 147. The wall 108 insulates the second portion 146 and the coil 34.
The embodiments described above can be appropriately combined. Furthermore, in the drawings described above, identical or corresponding portions are assigned the same reference signs. Note that the embodiments described above are merely exemplary and do not limit the invention.
Number | Date | Country | Kind |
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2018-225916 | Nov 2018 | JP | national |