JP2014120398A - Relay - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a relay excellent in heat dissipation performance.SOLUTION: A relay 1 includes: a housing 2; a ceramic base 10 fixed to the housing 2; a fixed terminal 15 having a fixed contact 17 and fixed to the ceramic base 10 to be stored within the housing 2; and a movable terminal 35 having a movable contact 36 forward and backward movable relative to the fixed contact 17 and electrically conducted with the fixed contact 17 by bringing the movable contact 36 into contact with the fixed contact 17. The ceramic base 10 is disposed so that at least a part thereof is exposed from the housing 2.

Description

  The present invention relates to a relay, and more particularly to a relay through which a relatively large current flows.

  Conventionally, various attempts have been made to release heat generated by the current flowing through the relay to the outside of the relay. For example, Patent Document 1 discloses an electromagnetic relay including an electromagnetic relay main body in which the periphery of a coil is covered with a thermally conductive resin layer and a cover that covers the electromagnetic relay main body. According to this electromagnetic relay, heat generated in the coil or the movable contact spring is radiated through the resin layer, so that the heat radiation performance is improved.

JP-A-10-172407

  By the way, this inventor experimented in which part in a relay the heat_generation | fever becomes large. As a result, it was confirmed that heat generation increased at the contact portion between the fixed terminal and the movable terminal.

  In the relay disclosed in Patent Document 1, the make side fixed contact is fixed to the coil bobbin. And the coil wound around the coil bobbin is covered with the cover through the resin layer. However, with this configuration, heat conduction may be insufficient between the coil bobbin and the coil, between the coil and the resin layer, and at the boundary surface between the resin layer and the cover. Then, as described above, the heat at the contact portion between the fixed terminal and the movable terminal that generate a large amount of heat becomes difficult to be released to the outside. As a result, the metal contact portion is likely to be oxidized, and there is a possibility that further heat generation is caused in the oxidized portion.

  A relay with a fixed contact fixed to a plastic substrate is also generally known. In this case, heat generated at the fixed contact is released to the outside through a plastic having a relatively low thermal conductivity. The Accordingly, in this case as well, as in the case of Patent Document 1, sufficient heat dissipation may not be performed.

  This invention is made | formed in view of the said situation, The objective is to provide the relay excellent in the thermal radiation performance.

  (1) In order to solve the above problem, a relay according to an aspect of the present invention includes a housing, a ceramic base fixed to the housing, a fixed contact, and fixed to the ceramic base. And a movable terminal that has a movable contact that can move forward and backward with respect to the fixed contact and that is energized between the fixed contact and the movable contact when the movable contact comes into contact with the fixed contact, The ceramic base is disposed so that at least a part thereof is exposed from the housing.

  According to this configuration, the heat of the fixed contact and the heat of a part of the movable contact generated by energizing the movable contact with the fixed contact are passed through the ceramic base having a relatively high thermal conductivity. It is discharged from the portion of the base that is exposed from the housing. Thereby, the heat generated at the fixed contact can be efficiently released to the outside.

  (2) Preferably, the ceramic base is arranged such that the fixed terminal is fixed to one surface and the other surface is exposed from the housing over the entire surface.

  According to this configuration, the heat generated at the fixed contact is released to the outside from the other surface of the ceramic base. This surface is exposed from the housing throughout. Therefore, the heat generated at the fixed contact can be released to the outside more efficiently.

  (3) Preferably, the fixed terminal is fixed to the ceramic base at a back side of a portion in contact with the movable contact in a portion where the fixed contact is provided.

  In the fixed terminal, the portion in contact with the movable contact in the portion where the fixed contact is provided is likely to be relatively hot. Therefore, by fixing the back side of the portion to the ceramic base, the heat generated at the fixed contact can be released to the ceramic base more quickly.

  (4) Preferably, the said fixed terminal is being fixed to the said ceramic base through the junction part comprised with the brazing | wax material by brazing.

  With this configuration, the fixed terminal can be firmly fixed to the ceramic base, and the heat generated at the fixed contact can be efficiently transferred to the ceramic base via the joint made of the brazing material having a relatively high thermal conductivity. I can escape.

  (5) More preferably, the fixed terminal and the joint, and the joint and the ceramic base are both in surface contact.

  With this configuration, since the contact area between the fixed terminal and the joint and the contact area between the joint and the ceramic base can be increased, the heat of the fixed terminal can be more efficiently released to the ceramic base.

  (6) Preferably, at least one of a concave portion and a convex portion is formed in a portion of the ceramic base that is exposed from the housing.

  With this configuration, since the surface area of the portion exposed from the housing in the ceramic base can be increased, the heat of the ceramic base can be efficiently released to the outside.

  According to the present invention, it is possible to provide a relay having excellent heat dissipation performance.

It is a perspective view of the relay which concerns on embodiment of this invention. It is AA sectional drawing in FIG. 1, Comprising: It is a figure which shows the state which the fixed terminal and the movable terminal are not contacting. It is a perspective view which shows a ceramic base and a fixed terminal. It is sectional drawing which shows the state which the fixed terminal and the movable terminal are contacting in a relay, Comprising: It is a figure shown corresponding to FIG. It is a side view which shows a part of ceramic base of the relay which concerns on a modification. It is a side view which shows a part of ceramic base of the relay which concerns on a modification. It is sectional drawing of the relay which concerns on a modification.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The embodiment of the present invention can be widely applied as a relay.

[Constitution]
FIG.1 and FIG.2 is the perspective view and sectional drawing which respectively show the relay 1 which concerns on this embodiment. 2 is a cross-sectional view taken along the line AA in FIG. 1 and shows a state where the fixed terminal and the movable terminal are not in contact with each other. The relay 1 according to the present embodiment is used, for example, for switching power in an aircraft, and is provided in an aircraft power distribution system (not shown).

  As shown in FIGS. 1 and 2, the relay 1 according to the present embodiment includes a housing 2, a ceramic base 10, and a relay body 20 having a fixed terminal 15 and a movable terminal 35. In the relay 1 according to the present embodiment, the movable contact 36 of the movable terminal 35 advances and retreats with respect to the fixed contact 17 of the fixed terminal 15 fixed on the ceramic base 10. Touch or separate. Thereby, the relay 1 switches between energization and non-energization.

  In the following, for convenience of explanation, the direction indicated by the arrow described above in FIG. 2 is the upper side or the upper side of the ceramic base 10 on which the relay main body 20 is disposed. In addition, the direction indicated by the arrow described as “lower” in FIG.

  The housing 2 has a rectangular bottom portion 3 and four wall portions 4 formed so as to extend upward from the respective sides of the bottom portion 3, and is formed in a substantially box shape in which these are integrally formed. ing. A rectangular hole 3 a into which the ceramic base 10 is fitted is formed at the center of the bottom 3. In addition, screw holes 2 a for fixing the relay 1 to a panel (not shown) of the aircraft power distribution system are formed at the four corners of the bottom 3. Two ribs 5 and 5 extending from the wall portion 4 into the housing 2 are formed on each of the pair of opposing wall portions 4 and 4 among the four wall portions 4. That is, four ribs 5 are formed in the housing 2. The rib 5 is formed from the bottom 3 to the upper end of the wall 4.

  In FIG. 3, the ceramic base 10 and the fixed terminal 15 of the relay 1 which concern on this embodiment are shown. As shown in FIG. 3, the ceramic base 10 is composed of a block-like member formed in a substantially rectangular parallelepiped shape. The ceramic base 10 is made of a ceramic material that is a material having relatively high thermal conductivity and high electrical insulation. In the present embodiment, aluminum nitride is used as the ceramic material constituting the ceramic base 10.

  The ceramic base 10 is formed in a rectangular shape in plan view. A plurality of (six in this embodiment) fixed terminals 15 are fixed to the upper surface 11 (the upper surface in FIGS. 2 and 3) which is one surface of the ceramic base 10. Further, as shown in FIG. 2, the ceramic base 10 has a rectangular hole in a state where the lower surface 12 (the lower surface in FIGS. 2 and 3) which is the other surface is exposed from the housing 2 over the entire surface. It fits in 3a and is fixed. The lower surface 12 is a flat surface.

  Each fixed terminal 15 is formed in a rectangular plate shape in plan view. As shown in FIG. 3, a fixed contact 17 is provided on one end side of the fixed terminal 15 in the longitudinal direction, and a bolt hole 15a is formed on the other end side. The fixed terminal 15 and the fixed contact 17 are made of a metal material having a relatively high conductivity.

  The fixed terminal 15 is fixed to the ceramic base 10 by brazing the back side portion of the portion where the fixed contact 17 is provided to the upper surface 11 of the ceramic base 10. As a result, a joint 16 made of a brazing material is formed between the back side of the fixed contact 17 and the upper surface 11 of the ceramic base 10. That is, the fixed terminal 15 is fixed to the ceramic base 10 through the joint portion 16 made of a brazing material. The junction 16 fixes a relatively wide range on the back side of the fixed contact 17 to the upper surface 11. That is, the back surface side of the fixed contact 17 and the upper surface of the joint portion 16 are in surface contact. Similarly, the lower surface of the joint portion 16 and the upper surface of the ceramic base 10 are in surface contact.

  The six fixed terminals 15 are arranged on the ceramic base 10 as described below. Specifically, three of the six fixed terminals 15 are respectively a part on one end side, a center part, and a part on the other end side of one long side of the upper surface 11 of the ceramic base 10. Is arranged. On the other hand, the remaining three of the six fixed terminals 15 are respectively connected to the one end side portion, the central portion, and the other end side portion of the other long side of the upper surface 11 of the ceramic base 10. Has been placed. Thereby, on the ceramic base 10, as shown in FIG. 3, three sets of a pair of fixed terminals 18 arranged so that the fixed contacts 17 face each other are arranged at equal intervals.

  As shown in FIG. 2, each fixed terminal 15 has a portion on the opposite side to the fixed contact 17 in the longitudinal direction of each fixed terminal 15 (portion where the bolt hole 15a is formed) protruding from the ceramic base 10. It is arranged on the ceramic base 10. Bolts 19 are inserted through portions of the fixed terminals 15 where the bolt holes 15a are formed. The bolt 19 is for fixing the fixed terminal 15 to a terminal block (not shown).

  As shown in FIG. 3, two grooves 11 a are formed on the upper surface 11 of the ceramic base 10. Each groove portion 11a is formed so as to extend between the long sides of the upper surface 11. Each groove 11 a is formed between a pair of adjacent fixed terminals 18. The groove 11a is for increasing the creeping distance between the pair of adjacent fixed terminals 18.

  The relay main body 20 has a fixed part 21 and a movable part 30. The relay main body 20 is configured such that the movable part 30 is displaced by a magnetic field generated in the fixed part 21.

  The fixed part 21 includes a case part 22, a support part 23, a coil part 24, and a fixed iron core 28. The fixed portion 21 is fixed to the housing 2.

  The case portion 22 is formed in a cylindrical shape from an insulating material (for example, plastic). Inside the case portion 22, a coil portion 24, a fixed iron core 28 and the like are accommodated.

  The support portion 23 is for fixing the case portion 22 to the housing 2. The support portion 23 is formed by bending a single sheet metal. The support portion 23 includes a flat portion 25 and a pair of leg portions 26.

  The flat portion 25 is formed in a square shape having a size capable of installing the case portion 22. At the four corners of the flat portion 25, shaft holes 25a are formed through which four connecting members 33 described later are slidably inserted in the vertical direction. Two screw hole portions 26 a are formed in each of the pair of leg portions 26. In the state where the bottom surface of the case portion 22 is installed and fixed to the flat portion 25, the support portion 23 is fastened to the ribs 5 of the housing 2 by bolts 27 with the screw hole portions 26 a. 22 is fixed to the housing 2.

  The coil part 24 is formed to be substantially cylindrical by winding a coil wire (not shown). The coil portion 24 is accommodated in the case portion 22 so that the central axis thereof is coaxial with the central axis of the case portion 22. The coil part 24 is configured such that a magnetic field is generated inside the coil part 24 so that the movable iron core 37 of the movable part 30 is attracted to the fixed iron core 28 side when a current flows through the coil wire.

  The fixed iron core 28 is composed of a metal member formed in a columnar shape. The fixed iron core 28 is disposed in a lower space in the coil portion 24 so that the central axis thereof is coaxial with the central axis of the coil portion 24.

  The movable portion 30 includes an upper plate 31 and a lower plate 32, four connecting members 33, three shaft portions 34, a movable terminal 35 fixed to the lower end portion of each shaft portion 34, and a movable iron core 37. And have. The movable portion 30 is formed by fixing these members with respect to each other, and is configured to slide in the vertical direction with respect to the fixed portion 21.

  The upper plate 31 is disposed above the case portion 22. The upper plate 31 is formed in a plate shape that is substantially rectangular in plan view. The lower plate 32 is disposed below the flat portion 25 of the support portion 23. The lower plate 32 is formed in a size substantially corresponding to the upper plate 31 when viewed from above, and is formed to be slightly thicker in the vertical direction than the upper plate 31.

  The connecting member 33 is an elongated rod-shaped member. Each connecting member 33 connects the upper plate 31 and the lower plate 32. Specifically, each connecting member 33 has one end fixed to a corner of the upper plate 31 and the other end fixed to a corner corresponding to the corner of the upper plate 31 in the lower plate 32. Yes. Each connecting member 33 is inserted into each shaft hole 25 a formed in the flat portion 25.

  The shaft portion 34 is formed so that one end thereof is fixed to the lower plate 32 and extends downward. Each shaft portion 34 is disposed between the two fixed contacts 17 in the pair of fixed terminals 18 as viewed from above. At the other end (lower end) of the shaft portion 34, a protruding portion 34 a that protrudes radially outward from the outer periphery of the shaft portion 34 is formed.

  The movable terminal 35 is formed in a rectangular plate shape in plan view. A through hole 35 a through which the shaft portion 34 is inserted is formed in the central portion of the movable terminal 35. The movable terminal 35 is supported by the protruding portion 34a in a state where the shaft portion 34 is inserted into the through hole 35a. A coil spring 39 is arranged between the upper surface of the movable terminal 35 and the lower surface of the lower plate 32 so as to surround the outer periphery of the shaft portion 34. The coil spring 39 biases the movable terminal 35 downward with respect to the lower plate 32.

  A movable contact 36 is provided at each end of the movable terminal 35. The movable terminal 35 and the movable contact 36 are made of a metal material having a relatively high conductivity, like the fixed terminal 15 and the fixed contact 17. The movable terminal 35 is arranged so that the two movable contacts 36 overlap the two fixed contacts 17 in the pair of fixed terminals 18 as viewed from above.

  The movable iron core 37 is composed of a metal member formed in a columnar shape. The movable iron core 37 is fixed to the upper plate 31 by bolts 38. The movable iron core 37 is accommodated in an upper space in the coil portion 24 such that its central axis is coaxial with the central axis of the coil portion 24 and its lower surface is spaced from the upper surface of the fixed iron core 28. The

  The movable iron core 37 is urged toward a direction away from the ceramic base 10 (upper side in FIG. 2) by a spring (not shown). Thereby, the movable part 30 including the movable iron core 37 is biased upward by the spring in a state where no current flows through the coil part 24. As a result, the movable part 30 is held in a state where the fixed contact 17 and the movable contact 36 are separated as shown in FIG.

[Relay operation]
In the relay 1 configured as described above, when a current flows through the coil portion 24, a magnetic field is formed around the coil portion 24. Then, the movable iron core 37 disposed in the magnetic field moves in a direction in which the magnetic resistance decreases. That is, the movable iron core 37 moves to the fixed iron core 28 side (lower side in FIG. 2) so as to reduce the magnetic resistance. Thereby, the movable portion 30 moves downward as a whole against the biasing force of the spring acting on the movable iron core 37. And the movable terminal 35 advances to the fixed terminal 15 side, the movable contact 36 and the fixed contact 17 contact, and an electric current flows between both. Thereby, the relay 1 will be in an ON state (refer FIG. 4).

  On the other hand, when no current flows through the coil part 24, the magnetic field generated around the coil part 24 disappears, so that the movable part 30 is pushed upward by the spring. As a result, the fixed contact 17 moves backward from the movable contact 36, so that no current flows between them, and the relay 1 is turned off (see FIG. 2).

[Heat flow generated at fixed contacts]
When the relay 1 is turned on as described above, a current flows in a current path including the fixed terminal 15 and the movable terminal 35, and Joule heat is generated in the path. Here, since a contact resistance is generated between the fixed contact 17 and the movable contact 36, the amount of heat generated at the fixed contact 17 is particularly large.

  The heat of the fixed contact 17 generated as described above is released into the air in the housing 2, while contacting the fixed terminal 15 through the joint portion 16 and the ceramic base 10 having a relatively high thermal conductivity. Is also transmitted by heat conduction. The heat from the fixed terminal 15 is transmitted through the ceramic base 10 and is released from the lower surface 12 of the ceramic base 10 to the outside. In the present embodiment, the ceramic base 10 is configured such that, for example, cooling air generated by a fan (not shown) provided in the aircraft power distribution system comes into contact with the lower surface 12 and heat is radiated from the lower surface 12 by the cooling air. It is cooled by being performed. Thereby, the heat of the ceramic base 10 can be efficiently discharged to the outside. The ceramic base 10 may be cooled by a fan provided separately from the aircraft power distribution system. Further, the ceramic base 10 may be naturally cooled by the outside air around the ceramic base 10 without providing a fan as described above.

  By the way, when the relay 1 is turned on and a current flows, the amount of heat generated at the fixed contact 17 becomes particularly large as described above. If the heat generated in this portion is not sufficiently released to the outside of the relay 1, the oxidation of the fixed contact 17 proceeds, and there is a possibility that further heat generation is caused in the oxidized portion.

  On the other hand, according to the relay 1 according to the present embodiment, the heat of the fixed contact 17 generated when the movable contact 36 contacts the fixed contact 17 and is energized has a relatively high thermal conductivity. Through the portion of the ceramic base 10 exposed from the housing 2. Thereby, the heat generated at the fixed contact 17 can be efficiently released to the outside.

  Further, according to the relay 1, the heat generated at the fixed contact 17 is released to the outside from the lower surface 12 of the ceramic base 10. The lower surface 12 is exposed from the housing 2 throughout. Therefore, the heat generated at the fixed contact 17 can be released to the outside more efficiently.

  Moreover, in the relay 1, the part which contacts the movable contact 36 in the fixed contact 17 tends to become comparatively high temperature. On the other hand, in the relay 1 according to the present embodiment, the back side of the portion is fixed to the ceramic base 10. Thereby, the heat generated at the fixed contact 17 can be released to the ceramic base 10 more quickly.

  Moreover, in the relay 1, the fixed terminal 15 is being fixed to the ceramic base 10 via the junction part 16 comprised with the brazing material by brazing. Thereby, the fixed terminal 15 can be firmly fixed to the ceramic base 10, and the heat generated at the fixed contact 17 can be efficiently released to the ceramic base 10 through the brazing material having a relatively high thermal conductivity. it can.

  In the relay 1, the back side of the fixed contact 17 and the upper surface of the joint portion 16 are in surface contact, and similarly, the lower surface of the joint portion 16 and the upper surface of the ceramic base 10 are in surface contact. As a result, the contact area between the fixed contact 17 and the joint 16 and the contact area between the joint and the ceramic base can be increased, so that the heat of the fixed contact 17 can be released to the ceramic base 10 more efficiently. it can.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. For example, you may implement the following modifications.

  (1) In the above-described embodiment, the surface 12 opposite to the surface on which the fixed terminal of the ceramic base 10 is fixed is configured as a flat surface, but this is not restrictive. FIG. 5 is a side view showing a portion near the lower surface 12 of the ceramic base 10 of the relay 1 according to the modification. As shown in FIG. 5, a plurality of recesses 12 a may be formed on the lower surface 12 of the ceramic base 10. FIG. 6 is a side view showing a portion near the lower surface 12 of the ceramic base 10 of the relay 1 according to another modification. As shown in FIG. 6, a plurality of convex portions 12 b may be formed on the lower surface 12 of the ceramic base 10.

  As a result, the surface area of the ceramic base 10 exposed to the outside of the housing 2 is increased, so that the heat generated at the fixed contact 17 can be released to the outside more quickly.

  (2) In the above-described embodiment, the fixed terminal 15 is brazed directly to the ceramic base 10. However, the present invention is not limited to this, and the fixed terminal 15 may be brazed to the plating portion formed on the ceramic base 10. Good.

  (3) FIG. 7 shows a cross-sectional view of the relay 1 according to a modification. In FIG. 7, the lower surface 12 of the ceramic base 10 of the relay 1 is in contact with one surface of the metal plate member 40 over the entire surface. In this way, after the heat of the ceramic base 10 is transmitted to the plate member 40, the heat is released to the outside from the lower surface of the plate member 40 and the portion of the upper surface of the plate member 40 where the ceramic base 10 is not in contact. Is done. In this way, by bringing a wide part of the ceramic base 10 (in the present modification, the entire lower surface 12) into contact with another member 40 having a large surface area and high thermal conductivity, the heat of the ceramic base 10 is increased. It can be discharged efficiently to the outside. In addition, the shape of the member 40 to be brought into contact with the ceramic base 10 is not limited to a plate shape, and may be another shape such as a block shape.

  (4) In the above embodiment, the relay 1 has a structure in which the movable terminal 35 is pressed against the fixed terminal 15 by the four connecting members 33. However, the present invention is not limited to this. For example, the structure of the relay may be a structure in which a movable terminal is provided at the lower end portion of the shaft provided coaxially with the central axis of the movable iron core, and the movable terminal is pressed against the fixed terminal. The structure of the relay may be a structure in which the movable terminal is in contact with the fixed terminal when no current is flowing through the coil part, and the movable terminal is separated from the fixed terminal when the current is flowing through the coil part. Even in these cases, the same effects as in the case of the above-described embodiment can be obtained.

  The present invention can be widely applied as a relay.

DESCRIPTION OF SYMBOLS 1 Relay 2 Housing 10 Ceramic base 15 Fixed terminal 16 Joint part 17 Fixed contact 35 Movable terminal 36 Movable contact

Claims (6)

A housing;
A ceramic base fixed to the housing;
A fixed terminal having a fixed contact, fixed to the ceramic base and housed in the housing;
A movable contact that is movable relative to the fixed contact; and a movable terminal that is energized with the fixed contact by contacting the fixed contact with the movable contact;
The relay according to claim 1, wherein at least a part of the ceramic base is exposed from the housing. The relay according to claim 1,
The relay is characterized in that the ceramic base is arranged such that the fixed terminal is fixed to one surface and the other surface is exposed from the housing over the entire surface. In the relay according to claim 1 or 2,
The relay, wherein the fixed terminal is fixed to the ceramic base on the back side of the portion that contacts the movable contact in the portion where the fixed contact is provided. The relay according to any one of claims 1 to 3,
The relay, wherein the fixed terminal is fixed to the ceramic base through a joint composed of a brazing material by brazing. The relay according to claim 4,
The relay, wherein the fixed terminal and the joint, and the joint and the ceramic base are both in surface contact. The relay according to any one of claims 1 to 5,
At least one of a recessed part and a convex part is formed in the part exposed from the said housing in the said ceramic base, The relay characterized by the above-mentioned.

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