JP7233247B2 - electromagnetic relay - Google Patents

Description

The present invention relates to electromagnetic relays.

In the electromagnetic relay, a relay main body portion including an electromagnetic drive portion, an electric contact portion, and a base is covered with a cover, and a fitting portion between the relay main body portion and the cover and between a terminal hole formed in the base and the terminal is provided. A common configuration is to seal the gap between them with a sealing resin. A thermosetting resin is often used for sealing, and since the electromagnetic relay needs to be heated in the sealing process, the cover is provided with a vent hole for adjusting the internal pressure of the electromagnetic relay. Sealed electromagnetic relays are shipped with air holes sealed to protect the relay body from the external environment. As a method of sealing the vent hole, the chimney-shaped vent hole is melted with a heated trowel, then recured (this process is called heat caulking), and the heat caulked part is protected with a cured resin. A common method is to Patent Literature 1 describes a sealing method for thermally caulking a ventilation hole formed in a cover of an electromagnetic relay.

In addition to heat crimping, a method for sealing the case of an electromagnetic relay has been proposed. In Patent Document 2, a protrusion that forms a vent hole is provided in a case that accommodates a relay body, a protrusion is formed at the tip of the protrusion, and a seal that engages with the protrusion and is detachably attachable to the protrusion is provided. An electromagnetic relay is described which can be sealed or opened by attaching a plug and can maintain a sealed structure with excellent airtightness.

JP-A-8-321239 Japanese Utility Model Laid-Open No. 58-2840

In recent years, there has been an increasing demand for the mounting of electromagnetic relays from the solder dip method to the reflow method, which is highly mountable. Reflow mounting exposes the electromagnetic relay to even higher temperatures. When the electromagnetic relay is exposed to high temperatures, the pressure inside the cover increases. Further, there is a demand for an electromagnetic relay that can prevent foreign objects, water droplets, and the like from entering the cover through the ventilation holes, and can prevent pressure increases inside the cover with a simple structure.

One aspect of the present disclosure includes an electromagnetic drive section, an electrical contact section, and a housing having an internal space that accommodates the electromagnetic drive section and the electrical contact section, wherein the housing communicates with the internal space. An electromagnetic relay comprising a ventilation hole and a sealing body that closes the ventilation hole, wherein a spiral groove is formed on the inner surface of the ventilation hole, and at least a portion of the sealing body moves according to pressure fluctuations in the internal space. is. Another aspect of the present disclosure comprises an electromagnetic drive section, an electrical contact section, and a housing having an internal space accommodating the electromagnetic drive section and the electrical contact section, wherein the housing includes the internal space and a sealing body that closes the ventilation hole, at least a portion of the sealing body moves according to pressure fluctuations in the internal space, and the housing further has the ventilation hole. A protrusion is provided, and the sealing body is formed of an elastic material, is attached to the tip of the protrusion, closes the vent hole, and is elastically deformed in accordance with pressure fluctuations in the internal space, thereby closing the protrusion. The electromagnetic relay has a flange at its tip with which the sealing body engages.

According to the above configuration, there is provided an electromagnetic relay that can prevent foreign objects, water droplets, etc. from entering the cover through the ventilation hole and can prevent the pressure inside the cover from increasing with a simple structure.

1 is a perspective view of an electromagnetic relay according to an embodiment; FIG. It is a side view of an electromagnetic relay. It is a perspective view showing the example of a structure of a relay main-body part. FIG. 3 is a vertical cross-sectional view of a vent hole of the electromagnetic relay according to the first embodiment; FIG. 3 is a vertical cross-sectional view showing a vent hole and a sealing body of the electromagnetic relay according to the first embodiment; FIG. 4 is a vertical cross-sectional view of the air vent when the internal pressure of the housing is increased; FIG. 10 is a vertical cross-sectional view of the vent when the internal pressure of the housing is lowered; FIG. 10 is a diagram showing a sealing body having a helical protrusion formed on the shaft; FIG. 11 is a plan view of a vent portion according to a first example of the second embodiment; FIG. 10 is a cross-sectional view of a vent portion according to a first example of the second embodiment; FIG. 4 is a cross-sectional view of a vent with a sealing body attached; FIG. 11 is a plan view of a ventilation hole portion according to a second example of the second embodiment; FIG. 10 is a cross-sectional view of a vent portion according to a second example of the second embodiment; FIG. 4 is a cross-sectional view of a vent with a sealing body attached; FIG. 11 is a plan view of a vent portion according to a third example of the second embodiment; FIG. 11 is a cross-sectional view of a vent according to a third example of the second embodiment; FIG. 4 is a cross-sectional view of a vent with a sealing body attached;

Next, embodiments of the present disclosure will be described with reference to the drawings. In the referenced drawings, similar components or functional parts are provided with similar reference numerals. In order to facilitate understanding, the scales of these drawings are appropriately changed. Moreover, the form shown in drawing is one example for implementing this invention, and this invention is not limited to the illustrated form.

Each embodiment described below relates to the configuration of a vent hole formed in a resin housing of an electromagnetic relay and a sealing body that seals the vent hole. As will be described in detail below, according to each embodiment, at least a portion of the sealing body moves as the pressure in the internal space of the housing changes, and the volume of the housing changes, thereby causing the internal pressure of the housing to change. to adjust.

First Embodiment FIGS. 1A and 1B show the appearance of an electromagnetic relay 50 according to a first embodiment. 1 is a perspective view of the electromagnetic relay 50, and FIG. 1B is a side view of the electromagnetic relay 50 on the front side in FIG. 1A. An electromagnetic relay 50 shown in FIGS. 1A and 1B has a configuration in which a main body of the relay is covered with a cover 11 that is a box-shaped resin molded product. In the electromagnetic relay 50, the fitting portion between the base 9 and the cover 11, which are molded resin products, and the gap between the terminal holes formed in the base 9 and the terminals 18 are sealed with a thermosetting resin. Thereby, the airtightness of the bottom surface 9b side of the electromagnetic relay 50 is ensured. A housing 20 of the electromagnetic relay 50 is composed of the base 9 and the cover 11 . The base 9 constitutes the bottom wall of the housing 20 , and the cover 11 constitutes the peripheral wall of the housing 20 .

A vent hole 90 is formed in the wall portion 111 on the upper side of the cover 11 to prevent the internal pressure of the housing 20 from increasing during the sealing process. In the case of conventional sealed electromagnetic relays, the ventilation holes are sealed by heat caulking. On the other hand, in the case of the electromagnetic relay 50 according to the present embodiment, by sealing the ventilation hole 90 with a sealing body to be described later, intrusion of foreign matter, water droplets, etc. from the ventilation hole 90 is prevented, and the inside of the housing is prevented. To prevent the pressure rise of , with a simple configuration.

FIG. 2 is a perspective view showing a configuration example of the main body of the electromagnetic relay 50. As shown in FIG. In FIG. 2, the cover 11 is shown transparently to show the internal configuration, and the sealing member 120 that closes the vent hole 90 is omitted. In FIG. 2, as an example, the electromagnetic relay 50 is a hinge-type electromagnetic relay, but it may be another type of electromagnetic relay. For convenience of explanation, the longitudinal direction of the base 9 is defined as the front-rear direction shown in FIG. 2, and the left-right direction and the vertical direction are defined as shown in FIG.

As shown in FIG. 2, the electromagnetic relay 50 includes an electromagnetic drive unit 30 including a coil 4, an iron core (not shown), a yoke 12, an armature 3, a hinge spring 10 and a card 6, and movable contacts each of which is an elastic member. and a contact portion 40 including an electrode 7 of a fixed contact and an electrode 8 of a fixed contact. An electrode 7 made of a conductive plate member is fixed at its lower end to a base 9 and has a movable contact 1 at its free end. The electrode 8 is fixed at its lower end to the base 9 and has a fixed contact 2 at its free end. Protrusions 15 supporting the electrodes provided on the inner surface of the rear wall of the cover 11 support the fixed contacts 2 from the rear side by coming into contact with the fixed contacts 2 . When the coil 4 is not energized and the contact portion 40 is open, the restoring force of the hinge spring 10 holds the armature 3 at the contact open position. When the coil 4 is energized from this state, the armature 3 is attracted to the iron core 5 and oscillates. Accordingly, the card 6 is pushed rearward and moves, pushing the electrode 7 toward the electrode 8 side. As a result, the movable contact 1 comes into contact with the fixed contact 2, and the contact portion 40 is closed. Terminals 18 are drawn out from the bottom surface 9b of the base 9 for connecting electrical parts such as the coil 4, the electrodes 7, and the electrodes 8 to the outside.

FIGS. 3 to 7 show the configurations of the vents and the seals that seal the vents 90. FIG. 3 to 6 are vertical cross-sectional views of the cover 11 near the ventilation hole 90 taken along a plane perpendicular to the front-rear direction. In FIG. 3, the sealing body 120 is omitted for convenience of explanation. As shown in FIGS. 1A and 3, a concave portion 91 recessed downward is formed on the upper surface 11b of the cover 11 at the corner between the upper surface 11b and the right side surface 11a. A columnar projection 93 is formed upwardly projecting from the bottom surface of the recess 91 . Ventilation hole 90 is formed to communicate with the internal space of housing 20 along the central axis of projecting portion 93 .

As shown in FIGS. 3 and 4, a spiral groove 94 is formed on the inner peripheral surface 93a of the projecting portion 93. As shown in FIGS. As shown in FIG. 4, the vent hole 90 is sealed with a sealing body 120 of cured resin. The sealing body 120 has a head portion 121 and a columnar shaft portion 122 fitted in the vent hole 90 . The shaft portion 122 has an outer diameter substantially equal to the inner diameter of the inner peripheral surface 93a, and does not come off from the ventilation hole 90 due to the frictional force with the inner peripheral surface 93a due to vibrations that are normally assumed. Furthermore, in a situation where the electromagnetic relay 50 is exposed to high temperatures such as solder reflow, the shaft portion 122 shifts upward inside the ventilation hole 90 as the internal pressure of the housing 20 rises, and as the internal pressure of the housing 20 decreases, downwards inside the vent hole 90. The outer diameter of the head portion 121 is larger than the outer diameter of the shaft portion 122 . This configuration makes it possible to adjust the internal pressure of the housing 20 by changing the volume of the housing 20 as the internal pressure of the housing 20 fluctuates.

FIG. 5 shows a state in which the internal pressure of the housing 20 has increased. As shown in FIG. 5, when the internal pressure of the housing 20 increases, the sealing member 120 is pushed by the air inside the housing 20 and is displaced upward. At this time, a gap is formed between the bottom surface 121a of the head portion 121 and the tip end surface 93c of the projecting portion 93 . As a result, the air inside the housing 20 can flow out mainly through the grooves 94 as indicated by the arrow E in FIG.

After that, when the internal pressure of the housing 20 decreases, as shown in FIG. 6, air from the outside flows into the housing 20 through the grooves 94, and the sealing member 120 is drawn downward into the housing 20. It shifts back to its original position shown in FIG. In the state shown in FIG. 4, the bottom surface 121a is in close contact with the tip surface 93c, and the housing 20 is hermetically sealed by the sealing body 120. As shown in FIG. Therefore, in the state of FIG. 4, foreign matter, water droplets, etc. are prevented from entering the housing 20 .

As a modification of the first embodiment described above, a helical protrusion that is screwed into the groove 94 may be formed on the outer peripheral surface of the shaft portion 122 . FIG. 7 shows a sealing body 120A in which a spiral projection 125 is formed on the outer peripheral surface of the shaft portion 122. As shown in FIG. In such a configuration, when the internal pressure of housing 20 rises, the air inside housing 20 flows out through a slight gap between groove 94 and the outer peripheral surface of sealing body 120A. At this time, the sealing member 120A moves upward while being rotated by being pushed by the air due to the engagement between the projection 125 and the groove 94. As shown in FIG. Further, when the internal pressure of the housing 20 decreases, the sealing body 120A moves downward while rotating in the opposite direction to when the pressure rises, together with the flow of air drawn into the housing 20 .

Also in the case of the modified example, it is possible to avoid an increase in the internal pressure of the housing 20 . Further, in the state where the sealing body 120A is at the position shown in FIG. 4, the housing 20 can be hermetically sealed.

The sealing member 120 is preferably made of a member such as an elastic resin so as to function as an elastic plug that closes the ventilation hole 90 . On the other hand, it is preferable that the sealing body 120A be a member with relatively high hardness. This is so that the protrusion 125 and the groove 94 are engaged with each other and the sealing body 125A rotates and moves up and down smoothly.

The sealing bodies 120 and 120A may be produced as resin molded products, or may be produced by applying resin to the vent hole 90 portion. When the sealing body is formed by applying resin, an appropriate amount of resin is applied to the vent hole 90 portion so that the shaft portion 122 that enters the vent hole 90 and the head portion 121 are formed on the tip side of the shaft portion 122 . apply.

When the sealing bodies 120 and 120A are formed by applying the resin to the vent holes, it is preferable to select a resin whose viscosity before curing is not too low. This is to prevent uncured adhesive from entering the housing 20 through the vent hole 90 . By appropriately selecting the viscosity and wettability of the resin before curing, the resin does not enter up to the grooves 94 to form a shape without projections 125 like the sealing body 120 , or the resin extends up to the grooves 94 . It is possible to create a shape like the encapsulant 120A in such a way that it is recessed.

When the sealing body 120 without spiral projections is made by coating, the sealing body 120 has low hardness and elasticity after curing so that it functions as an elastic plug that closes the ventilation hole 90 . The choice of resin is preferred. Also, in this case, it is preferable to select a resin that does not have too high adhesive strength. This is to allow the sealing body 120 to shift and move inside the vent hole 90 according to fluctuations in the internal pressure of the housing 20 .

On the other hand, when the sealing body 120A having spiral protrusions is formed by coating, it is preferable to select a resin having a high hardness. This is because it is possible to smoothly move up and down while the sealing body 120A rotates while the protrusion 125 and the groove 94 are engaged with each other. Also in this case, it is possible to select a resin whose adhesive strength is not too high, in order to allow the sealing body 120A to move so as to be displaced inside the vent hole 90 according to fluctuations in the internal pressure of the housing 20. preferable.

In the first embodiment described above, the ventilation holes 90 are formed in the columnar protrusions, but there is also a configuration example in which the ventilation holes 90 are formed in the planar wall of the housing 20 . Also, the ventilation hole 90 may be formed in a peripheral wall other than the wall portion 111 of the housing 20 .

2nd Embodiment Next, 2nd Embodiment is described. The second embodiment relates to a configuration in which an elastic sealing member for closing the air vent is attached to the tip of the protrusion forming the air vent. In this embodiment, as the internal pressure of the housing 20 rises, the sealing member elastically deforms to change the volume of the housing 20 , thereby adjusting the internal pressure of the housing 20 . The "elastic deformation" of the sealing body accompanying pressure fluctuations in the housing 20 in the second embodiment is one aspect of the "movement of the sealing body" accompanying pressure fluctuations in the housing 20 in the first embodiment. be. The configuration of the electromagnetic relay according to the second embodiment is the same as that of the first embodiment described with reference to FIGS. 1A-1B and FIG. 1A-1B and each component illustrated in FIG. 2 will be described as appropriate. Three examples according to the second embodiment will be described below.

First Embodiment FIGS. 8A-8C show a sealing structure with a vent hole and a sealing body according to a first embodiment. 8A is a plan view of the vicinity of the air hole 90 viewed from above, and FIGS. 8B and 8C are vertical cross-sectional views of the vicinity of the air hole 90 of the cover 11 taken along the line AA' in FIG. 8A. Note that the sealing body 220 is omitted in FIGS. 8A and 8B for convenience of explanation. As shown in FIGS. 8A-8C, in this embodiment, a recess 191 is formed at the corner between the top surface 11b and the right side surface 11a of the cover 11. As shown in FIGS. A columnar projection 193 that projects upward is formed on the bottom surface of the recess 191 . Ventilation hole 90 communicates with the internal space of housing 20 along protrusion 193 .

A flange 194 that protrudes radially outward from the protrusion 19 is formed at the tip of the protrusion 193 . The flange 194 is formed in an annular shape when viewed from above. At the tip of the protruding portion 193, a lid portion 220a having an inner surface shape substantially equal to the outer surface shape of the flange 194, and a projection 220b that protrudes inward from the lower end of the lid portion 220a and engages with the flange 194 is provided. 220 is attached (FIG. 8C). The inner diameter size of the inner tip of the projection 220 b is smaller than the outer diameter size of the flange 194 . With this configuration, the sealing body 220 airtightly seals the ventilation hole 90 when the internal pressure of the housing 20 shown in FIG. 4 is not increased. The sealing body 220 is made of an elastic body obtained by curing an elastic resin, for example. The encapsulant 220 can be removably attached to the protrusion 193 .

Since the sealing body 220 has elasticity, when the pressure inside the housing 20 increases from the state shown in FIG. 8C, in which the flange 194 and the inner surface of the lid portion 220a are in close contact with each other, the sealing body 220 shrinks when the pressure in the housing 20 decreases. Therefore, the sealing body 220 can prevent the pressure inside the housing 20 from increasing, and the sealing body 220 can adjust the internal pressure of the housing 20 . Incidentally, as the internal pressure of the housing 20 rises or falls, air can also flow through a small gap between the inner surface of the sealing body 220 and the outer surfaces of the protrusions 193 and 194 . In a state in which the sealing body 220 is attached to the vent hole 90 , foreign matter, water droplets, and the like are prevented from entering the housing 20 .

Second Embodiment FIGS. 9A-9C show a sealing structure with a vent and a sealing body according to a second embodiment. The second embodiment corresponds to the configuration in which the flange 194 in the first embodiment has an inclined surface on the upper surface side. 9A is a top plan view of the vicinity of the ventilation hole 90, and FIGS. 9B-9C are vertical cross-sectional views of the vicinity of the ventilation hole 90 of the cover 11 taken along line BB' of FIG. 9A. Note that the sealing body 320 is omitted in FIGS. 9A and 9B for convenience of explanation. As shown in FIGS. 9A-9C, the bottom surface of the recess 191 is formed with a protrusion 293 that protrudes upward. Ventilation hole 90 communicates with the internal space of housing 20 along protrusion 293 .

A flange 294 that protrudes radially outward is formed at the tip of the projecting portion 293 . The flange 294 is formed in an annular shape when viewed from above, and an annular inclined surface 294a is formed on the outer edge portion of the upper surface of the flange 294, which is inclined downward toward the radially outer side. At the tip of the protrusion 293 is a cylindrical portion 320a having an inner diameter approximately equal to the outer diameter of the flange 294, and an open lower end of the cylindrical portion 320a extending inwardly so as to engage the bottom surface of the flange 294. A sealing body 320 having a projection 320b projecting toward is attached. In the state shown in FIG. 9C in which the internal pressure of the housing 20 is not increased, the sealing body 320 hermetically seals the ventilation hole 90 . The sealing body 320 is formed of an elastic body obtained by curing an elastic resin, for example. The encapsulant 320 can be removably attached to the protrusion 293 . In the case of this embodiment, since the flange 294 is formed with an inclined surface 294a, the lower end of the sealing body 320 is slid along the inclined surface 294a when the sealing body 320 is attached to the projecting portion 293. The seal 320 can be fitted to the flange 294 in this way. With this configuration, the sealing body 320 can be easily fitted to the projecting portion 293 . Incidentally, as the internal pressure of the housing 20 rises or falls, air can also flow through a small gap between the inner surface of the sealing body 320 and the outer surfaces of the projections 293 and 294 .

Further, according to this embodiment, in the state shown in FIG. 9C in which the sealing body 320 is attached to the projecting portion 293, a gap S is formed between the inclined surface 294a and the inner surface of the upper wall portion 321 of the sealing body 320. be done. In the case of this embodiment as well, when the internal pressure of the housing 20 rises, the sealing body 320 is elastically deformed so as to expand and receives the air from inside the housing 20, thereby increasing the pressure inside the housing 20. to prevent In particular, in the case of the present embodiment, the air flowing out from the inside of the housing 20 can be received by the gap S, so the ability to adjust the internal pressure of the housing 20 can be enhanced.

Third Embodiment FIGS. 10A-10C show a sealing structure with a vent hole and a sealing body according to a third embodiment. The third embodiment corresponds to a configuration in which the flange 194 is grooved. 10A is a top plan view of the vicinity of the ventilation hole 90, and FIGS. 10B-10C are longitudinal sectional views of the vicinity of the ventilation hole 90 of the cover 11 taken along line CC' in FIG. 10A. Note that the sealing body 220 is omitted in FIGS. 10A and 10B for convenience of explanation. As shown in FIGS. 10A-10C, the bottom surface of the recess 191 is formed with a protrusion 393 that protrudes upward. The vent hole 90 communicates with the internal space of the housing 20 along the central axis of the projecting portion 393 .

A flange 394 that protrudes radially outward from the projection 393 is formed at the tip of the projection 393 . The flange 394 is formed in an annular shape when viewed from above, and two grooves 394b extending in the vertical direction are formed in opposite left and right portions of the flange 394 . At the tip of the projecting portion 393, a lid portion 220a having an inner surface shape approximately equal to the outer diameter shape of the flange 394, and a projecting portion 220b projecting inward from the lower end of the lid portion 220a and engaging with the bottom surface of the flange 394 are provided. An encapsulant 220 is attached. The sealing body 220 closes the ventilation holes 90 .

When the internal pressure of the housing 20 rises, the sealing body 220 is elastically deformed so as to expand. At this time, the groove 394b communicates with the ventilation hole 90 by deforming the lid portion 220a so as to bulge upward. With this configuration, it is possible to adjust the internal pressure of the housing 20 by changing the volume of the housing 20 as the internal pressure of the housing 20 fluctuates. Note that when the internal pressure of the housing 20 increases, an air flow is formed through the grooves 394b as indicated by the arrow in FIG. 10C to prevent the internal pressure of the housing 20 from increasing. When the internal pressure of the housing 20 is reduced, external air can be drawn into the housing 20 through the grooves 394b.

As described above, even in the case of the electromagnetic relay according to the second embodiment, it is possible to prevent foreign matter, water droplets, etc. from entering the cover through the ventilation holes, and to prevent an increase in pressure inside the cover with a simple structure. .

In the second embodiment described above, the flange is annularly formed at the tip of the protruding portion, but this configuration may be modified as appropriate. For example, the planar shape of the flange can be modified as appropriate, and the shape of the sealing body can be modified accordingly.

Although the present invention has been described using exemplary embodiments, those skilled in the art can make modifications to the above-described embodiments and various other modifications, omissions, and modifications without departing from the scope of the present invention. It will be appreciated that additions can be made.

The shapes of the cover, base, terminals, and the like shown in the above-described embodiments are examples, and the present invention can be applied to various shapes of electromagnetic relays having housings in which ventilation holes are formed.

9 base 11 cover 18 terminal 20 housing 50 electromagnetic relay 90 vent 91, 191 recess 93, 193, 293, 393 protrusion 94 groove 120, 120A, 220, 320 sealing body 121 head 122 shaft 194, 294, 394 Flange 220a Lid 220b, 320b Projection 294a Inclined surface 320a Cylindrical portion 394b Groove S Gap

Claims (2)

An electromagnetic drive unit, an electrical contact unit, and a housing having an internal space that accommodates the electromagnetic drive unit and the electrical contact unit,
The housing includes a vent leading to the internal space and a sealing body that closes the vent,
A spiral groove is formed on the inner surface of the vent,
An electromagnetic relay in which at least a portion of the sealing body moves with pressure fluctuations in the internal space. An electromagnetic drive unit, an electrical contact unit, and a housing having an internal space that accommodates the electromagnetic drive unit and the electrical contact unit,
The housing includes a vent communicating with the internal space and a sealing body that closes the vent, and at least a portion of the sealing body moves with pressure fluctuations in the internal space,
The housing further comprises a protrusion having the air hole,
The sealing body is formed of an elastic material, is attached to the tip of the projecting part, closes the air hole, and is elastically deformed according to pressure fluctuations in the internal space,
The tip of the protrusion has a flange with which the sealing body engages,
electromagnetic relay.

Images