JP2008004374A - Electromagnetic relay - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnetic relay capable of securing stable fluid-tightness after a heating process in high temperatures and preventing water, a coating material, and contaminated gas from penetrating into the inside of the electromagnetic relay while causing no operation fault and contact fault. <P>SOLUTION: In this sealed electromagnetic relay composed of an electric contact part, an electromagnetic driving part, a molded resin base, and a molded resin cover 21, an internal pressure adjusting mechanism part 2 is provided in the molded resin cover 21, the internal pressure adjusting mechanism part 2 is equipped with a through hole 5 for air vent, a recessed part 20 provided in the periphery part of the through hole 5, an internal pressure adjusting lid 3 of magnetic metal covering the through hole 5 and an elastic body ring 4 mounted to the internal pressure adjusting lid 3, and the bottom faces of the internal pressure adjusting lid 3 and the recessed part 20 are pressure-bonded to the elastic body ring 4 by suction force by a magnet ring 6 provided on the inside of the molded resin cover 21. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electromagnetic relay, and more particularly to an electromagnetic relay suitable as an on-vehicle electrical component capable of preventing a failure due to a heat treatment process during board mounting.

  An electromagnetic relay that has an electromagnetic contact open / close function and is widely used for in-vehicle use has an electric contact, an electromagnetic drive portion, and a main body portion made of a molded resin base for mounting the same, covered with a molded resin cover. In order to ensure reliability, it is generally hermetically sealed with a thermosetting sealing resin or the like. In this way, when the electromagnetic relay is completely sealed from the outside, the escape route of the gas inside the relay is closed, and in the reflow heating process such as when the relay terminal is soldered to the circuit board, particularly due to thermal stress, Airtight breakage is likely to occur at the interface between a metal and a resin having different coefficients of thermal expansion, or at the bonding portion between the molding resin and the sealing resin. The electromagnetic relay that caused hermetic failure allowed water and solvents to enter from the outside, causing operation failure and contact failure.

  6 is an exploded perspective view of a conventional general electromagnetic relay, and FIG. 7 is a longitudinal sectional view for explaining the structure of a through hole portion of a molded resin cover of the electromagnetic relay shown in FIG. Is an unsealed (non-sealed) type through-hole structure, and FIG. 7B shows a sealed (sealed) type through-hole structure. In FIG. 6, the electromagnetic drive part 14 holding the electrical contact part is mounted on the molded resin base 12 to constitute a main body part, and the whole main body part is covered with the molded resin cover 1 molded. The gap between the molded resin base 12 and the inserted terminal and the gap between the main body and the molded resin cover 1 are sealed with a sealing resin 15.

  As shown in FIGS. 6 and 7, the conventional electromagnetic relay is provided with a through hole 5 projecting outward on the top surface of the molded resin cover 1 by molding, and a concave portion is formed on the outer periphery of the through hole 5. 16 is provided. Conventionally, an unsealed electromagnetic relay having a through hole 5a that remains in a penetrating state, and a sealed electromagnetic relay that has a through hole 5b in which a portion of the through hole 5 is melted and closed by heat caulking are sealed. Two types of electromagnetic relays were provided.

  Conventionally, when the thermal stress in the reflow heating process is assumed, the former unsealed electromagnetic relay is mainly used. In general, since the molded resin cover 1 is commonly used for a seal-type electromagnetic relay, the top through-hole 5 has a shape and a hole required in consideration of moldability and heat caulking workability. The diameter condition must be met, which requires a certain size opening. Therefore, it is in a state where all contaminants easily enter from the outside of the electromagnetic relay through this opening. In particular, as an in-vehicle application, a coating agent may be applied to the entire surface of the printed circuit board after the electromagnetic relay is mounted on the printed circuit board by a reflow heating process. At this time, it is desirable to avoid application to the through-hole 5, but if a coating agent is applied to the through-hole 5, there is a possibility that the coating agent may enter the inside of the electromagnetic relay, causing an operation failure or contact contact. Direct cause of failure. Furthermore, in order to remove the residue of the flux at the time of solder connection, the mounted electromagnetic relay may be immersed and washed with the printed circuit board, and such a process cannot be applied to an unsealed electromagnetic relay. As described above, the unsealed electromagnetic relay in which the electromagnetic relay is not sealed has a significantly high risk, and is severely limited in its usage.

  On the other hand, in a conventional seal-type electromagnetic relay, a sealing structure is strengthened so that an airtight breakdown does not occur even by thermal stress in a reflow heating process. For example, in FIG. 6, there is a method in which the sealing resin 15 is changed to a sealing resin having higher heat resistance and stronger adhesive properties with the molded resin cover 1 and the molded resin base 12 to increase the airtightness. .

  Further, in Patent Document 1, a reinforcing rib is provided on the inner wall of the molded resin cover, and the joint strength of the reinforcing rib is increased so that the sealing resin can easily flow in, so that the bonding strength is increased. A technique to raise the limit point for expansion failure is shown, and in Patent Document 2, a filter having a minute porous air hole is installed in a part of a molded resin base to prevent expansion failure at high temperatures. Technology to do is shown.

JP 2002-367498 A JP-A-5-242784

  Since the conditions for the actual reflow heating process are diverse, the technology for enhancing the heat resistance and adhesive strength of the sealing resin as described above should maintain its airtightness against all of them. I can't. This is because the inside of the electromagnetic relay becomes high pressure due to high temperature, and there is a limit point that causes hermetic failure due to excessive thermal expansion. Under various reflow heating conditions, it may be assumed that the limit point causing the hermetic failure is exceeded. Furthermore, since the sealing resin is susceptible to changes depending on application conditions, thermosetting conditions, or external conditions such as ambient temperature and humidity, its adhesive properties are likely to change, and its adhesive strength is completely constant during the manufacturing process. Control is difficult. Further, the limit of hermetic failure is determined by the weakest portion of the adhesive sealing portion. The limit point that results in hermetic failure due to various factors as described above varies depending on the product.

  For example, the technique of providing reinforcing ribs on the inner wall of the molded resin cover and promoting the inflow of the sealing resin as in Patent Document 1, the molded resin cover itself has a more rigid structure, and the limit point against expansion failure is increased. However, stress concentrates on other joints such as the sealing resin and metal terminal interface.

  On the other hand, in the technology applying the porous filter shown in Patent Document 2, it is generally assumed that the heat resistance limit of the filter itself is lower than that of the molded resin base. For example, more severe reflow heating conditions such as lead-free solder conditions Then, a stable porous state may not be maintained. In addition, there are many technical problems such as the structure of fixing the filter to the molded resin base and the fixing method, and the application is not easy at present and there is a problem in productivity. Furthermore, there is a problem that the material cost is greatly increased due to the use of a special polymer material.

  Therefore, in view of the above-mentioned problems, the object of the present invention is to ensure stable airtightness even after the high-temperature heating process, and to prevent water and coating materials, and further, contamination gas from entering the electromagnetic relay. It is an object of the present invention to provide an electromagnetic relay that can be operated and has no contact failure.

  By solving the above problems, it is possible to clean and apply a coating agent after mounting the substrate by reflow heating.In addition, even in a gas atmosphere that generally affects the contact point and may cause contact failure even after reflow heating. An electromagnetic relay that can operate stably is obtained.

  In order to solve the above problems, an electromagnetic relay according to the present invention includes a main body portion including an electrical contact portion, an electromagnetic drive portion, and a molded resin base, and a molded resin cover that covers the main body portion, and the molded resin base. In the electromagnetic relay in which the gap between the electrical contact portion or the terminals constituting a part of the electromagnetic drive portion and the gap between the main body portion and the molded resin cover are sealed with a sealing resin, An internal pressure adjusting mechanism is provided on at least one of the molded resin cover or the molded resin base, and the internal pressure adjusting mechanism is installed on the air vent through hole, the internal pressure adjusting lid covering the through hole, and the outer periphery of the through hole. An elastic ring is provided, and the inner pressure adjusting lid and the outer peripheral portion of the through hole are pressed against the elastic ring by an attractive force of a magnet or an elastic force of a spring.

  The through hole is a hole provided in a protruding portion of the molded resin cover that extends toward the outside of the molded resin cover. The through hole has a recess in the outer peripheral portion of the through hole, and the internal pressure adjustment lid is in the recess. It is made of a magnetic metal having an outer shape to be fitted, and the elastic ring is attached to a portion of the internal pressure adjusting lid that faces the bottom surface of the concave portion, and a portion that faces the concave portion inside the molded resin cover. A magnet ring that is fitted, covers the through-hole by pushing and inserting the internal pressure adjustment lid into the recess, and the internal pressure adjustment lid and the magnetic pressure adjustment force by the magnetic pressure force between the internal pressure adjustment lid and the magnet ring; The bottom surface of the recess may be crimped to the elastic ring.

  In addition, the through hole is a hole provided in a protruding portion that is formed on the molded resin base and faces the outside of the molded resin base, and has a concave portion on the outer periphery of the through hole. It is made of a magnetic metal having an outer shape that fits into the recess, and the elastic ring is attached to a portion of the internal pressure adjustment lid that faces the bottom surface of the recess, and faces the recess inside the molded resin base. A magnet ring fitted to the part, covering the through-hole by inserting and inserting the internal pressure adjustment lid into the recess, and adjusting the internal pressure by a magnetic attractive force between the internal pressure adjustment lid and the magnet ring The lid and the bottom surface of the recess may be pressure-bonded to the elastic ring.

  In addition, a protrusion is provided on each of the side surface of the recess in the outer peripheral portion of the through hole and the side surface of the internal pressure adjustment lid, and the protrusion on the side surface of the internal pressure adjustment lid is located inside the protrusion on the side surface of the recess. As described above, the internal pressure adjustment lid may be inserted into the concave portion, and the displacement amount of the internal pressure adjustment lid may be limited by the two protrusions.

  In addition, the through hole is a hole provided in a protruding portion that is formed on the molded resin cover and faces the outside of the molded resin cover. The through hole has a concave portion on an outer peripheral portion of the through hole. The elastic ring is attached to a portion of the internal pressure adjusting lid facing the bottom surface of the concave portion, a return spring is fixed to a side surface of the internal pressure adjusting lid, and an outer periphery of the through hole Protruding portions are provided on the side surfaces of the concave portions of the concave portions, and the internal pressure adjusting lid is pushed into and inserted into the concave portions so that the front ends of the return springs are located inside the protruding portions on the side surfaces of the concave portions to cover the through holes. In addition, the inner pressure adjustment lid and the bottom surface of the recess may be pressed against the elastic ring by the elastic force of the return spring.

  In addition, the through hole is a hole provided in a protruding portion that is formed on the molded resin base and faces the outside of the molded resin base, and has a concave portion on the outer periphery of the through hole. The elastic ring is attached to a portion of the internal pressure adjusting lid facing the bottom surface of the concave portion, a return spring is fixed to a side surface of the internal pressure adjusting lid, and an outer periphery of the through hole Protruding portions are provided on the side surfaces of the concave portions of the concave portions, and the internal pressure adjusting lid is pushed into and inserted into the concave portions so that the front ends of the return springs are located inside the protruding portions on the side surfaces of the concave portions to cover the through holes. In addition, the inner pressure adjustment lid and the bottom surface of the recess may be pressed against the elastic ring by the elastic force of the return spring.

  As described above, the electromagnetic relay of the present invention has a mechanism for adjusting the internal pressure. That is, during high temperature overheating, air flow is secured so as to prevent an increase in internal pressure, and expansion failure of the adhesive interface and molding resin is prevented. When it returns to room temperature, it keeps airtight again to maintain water resistance, and it can also prevent the invasion of coating agent and gas from the outside of the electromagnetic relay, avoiding operation trouble and contact trouble .

  As described above, according to the present invention, it is possible to ensure stable airtightness even after the high-temperature heating process, and to prevent water and coating materials, and further, contamination gas from entering the electromagnetic relay, , An electromagnetic relay without contact obstruction is obtained.

  More specifically, it enables cleaning after substrate mounting by reflow heating and application of a coating agent, and even in a gas atmosphere that generally affects contacts and may cause contact failure even after reflow heating. An electromagnetic relay that can operate stably is obtained.

  The present invention also utilizes an internal pressure adjusting mechanism formed by a combination of an internal pressure adjusting lid and a molded resin cover or molded resin base having a through hole similar to a conventional through hole, and is used in the present invention. The molded resin cover and the molded resin base can be used in common for the unsealed electromagnetic relay, and a conventional unsealed electromagnetic relay can be obtained if the internal pressure adjustment lid is not used.

  Embodiments of an electromagnetic relay according to the present invention will be described below with reference to the drawings.

  FIG. 1 is a view for explaining a first embodiment of an electromagnetic relay according to the present invention. FIG. 1 (a) is an exploded perspective view of the entire molded resin cover 21 used in this embodiment. FIG. 1B is an exploded perspective view of the internal pressure adjusting mechanism 2 formed on the molded resin cover 21, and FIG. 1C is a cross-sectional view of the internal pressure adjusting mechanism 2.

  The electromagnetic relay of the present embodiment is the same as the conventional electromagnetic relay shown in FIG. 6 except for the internal pressure adjusting mechanism 2 provided on the molded resin cover 21, and an electromagnetic driving unit holding an electric contact part. 14 and a molded resin base 12 and a molded resin cover 21 covering the main body. The gap between the molded resin base and the component and the gap between the main body and the molded resin cover 21 are sealed. Sealed with a stop resin 15.

  In this embodiment, as shown in FIG. 1, the molded resin cover 21 has an internal pressure adjusting mechanism 2, and the internal pressure adjusting mechanism 2 includes an air vent through hole 5 and an internal pressure adjusting lid 3 that covers the through hole 5. And the elastic ring 4 installed on the outer peripheral portion of the through hole 5, and the through hole 5 is provided in a projecting portion toward the outside of the molded resin cover 21 formed in the molded resin cover 21, and the concave portion 20 is provided in the outer peripheral portion thereof. The inner pressure adjustment lid 3 is made of a magnetic metal having an outer shape that fits into the recess 20, the elastic ring 4 is attached to a portion of the inner pressure adjustment lid 3 that faces the bottom surface of the recess 20, and The magnet ring 6 is fitted in a portion of the molded resin cover 21 facing the recess 20, covers the through hole 5 by pushing the internal pressure adjustment lid 3 into the recess 20, and the internal pressure adjustment lid 3 and magnet ring 6 The bottom surface of the inner pressure control lid 3 and the recessed portion 20 is crimped to the elastic ring 4 by the magnetic attraction force of.

  Further, in the present embodiment, a stopper 8 as a projection is provided on the circumference of the side surface of the recess 20 and a return stopper 7 as a projection is provided on the circumference of the side surface of the internal pressure adjusting lid 3, and the return stopper 7 is a stopper. The inner pressure adjustment lid 3 is inserted into the recess 20 so as to be located inside the lower limit 8, and the inner pressure adjustment lid 3 is pushed up by both stoppers so as not to be detached from the recess 20.

  Further, in this embodiment, the ring-shaped magnet ring 6 is fitted from the opening side (inside side) of the molded resin cover 21 according to the position of the magnet ring fitting claw 9. The internal pressure adjusting lid 3 is made of nickel-plated iron having a high magnetic attraction force characteristic. In the internal pressure adjusting lid 3, the elastic ring 4 is fitted in the elastic ring mounting groove 10 on the lower surface in the insertion direction. Next, the internal pressure adjustment lid 3 is pushed into the recess 20, and at this time, the return stopper 7 is inserted over the stopper 8, and the bottom surface of the recess 20, the elastic ring 4, and the bottom surface of the internal pressure adjustment lid 3 are formed. Adhere to each other.

  FIG. 1C shows a state where the internal pressure adjusting lid 3 closes the through hole 5. The internal pressure adjusting lid 3 is attracted by the magnetic attractive force of the magnet ring 6, and the elastic ring 4 is in close contact with the bottom surface of the concave portion 20 of the molded resin cover 21, and airtightness is maintained at this portion. At this time, clearance is provided between the side surface of the recess 20 and the side surface of the internal pressure adjustment lid 3 so that the portions other than the return stopper 7 and the stopper 8 do not come into contact with each other. It is prevented from occurring. Furthermore, a trap stage 11 that is further depressed is provided on a part of the bottom surface of the recess 20, and serves as a trap that suppresses intrusion into the electromagnetic relay against inflow of debris generated from the stopper 8 and coating agent from the outside. is doing.

  In the present embodiment, the diameter of the outlet from which the through hole 5 protrudes is preferably 0.5 mm or more. The internal pressure adjusting lid 3 that closes the through-hole 5 can be made of a magnetic metal or the like that has been subjected to a weather resistance or corrosion resistance plating process. The elastic ring 4 is made of a material that has adhesiveness with the molding resin of the electromagnetic relay and has a function of blocking water and gas from entering from the outside. For example, it is possible to select a polymer elastic body that is generally a material that does not generate a gas that affects metal contacts, and that has weather resistance, corrosion resistance, and solvent resistance. The material is not limited to this as long as the material can obtain the function. In this embodiment, the return stopper 7 is formed integrally with the internal pressure adjusting lid 3 or is fixed to the internal pressure adjusting lid 3 by a method such as welding. The shapes of the through holes 5 and the like formed in the molded resin cover 21 are all formed by resin molding.

  The internal pressure adjusting lid 3 is pushed up by an increase in the internal pressure of the electromagnetic relay at a high temperature to ensure release of gas from the through hole. However, excessive push-up is restricted by the stopper 8 and the return stopper 7. At this time, it is preferable to adjust so that the gap in which the internal pressure adjusting lid 3 is separated from the bottom surface of the recess 20 is limited to 0.5 mm or less.

  FIG. 2 is a cross-sectional view showing the operating principle of the internal pressure adjusting mechanism 2. When the electromagnetic relay is heated in a reflow process or the like, the internal pressure of the electromagnetic relay increases and at the same time the magnetic attractive force of the magnet ring 6 decreases. At a certain temperature, the internal pressure force overcomes the magnetic attractive force, and the internal pressure adjustment lid 3 is pushed up by the internal pressure. At this time, the stopper 7 collides with the stopper 8 and excessive push-up is restricted, and the internal pressure adjusting lid 3 is prevented from being detached from the molded resin cover 21. Therefore, the gas inside the electromagnetic relay that has expanded from the through hole 5 passes and flows out. When the temperature decreases again, the magnetic attractive force is restored, and the internal pressure adjusting lid 3 is brought into close contact with the molded resin cover 21 so that the airtightness is maintained as it was.

In order to achieve the operation of FIG. 2, it is necessary to adjust the relationship between the internal pressure of the electromagnetic relay applied during heating and the magnetic attractive force of the magnet ring 6. Assuming that the normal temperature is 23 ° C. and the internal pressure of the electromagnetic relay is exactly 101325 Pa (= 1 atm), the relay internal pressure P (N / m ² ) per unit area at the heating temperature T (° C.) is expressed by the formula ( 1).

P (N / m ² ) = 101325 · (273 + T) / (273 + 23) (1)

At this time, if the area where the internal gas of the electromagnetic relay is in contact with the internal pressure adjustment lid 3 is S (m ² ), the force F ₁ (N) applied to the internal pressure adjustment lid 3 is expressed by Equation (2).

F ₁ (N) = 101325 · (273 + T) · S / (273 + 23) (2)

On the other hand, if the magnet ring 6 to be used has a magnetic flux density B ₀ (Wb / m ² ) at normal temperature and a temperature coefficient Br (% / ° C.), the magnetic flux density B _T (Wb / m ² ) at the heating temperature T (° C.). ) Becomes equation (3).

B _T (Wb / m ² ) = B ₀ + B ₀ · B _r · (T−23) (3)
However, it is assumed that B _T includes an element of a gap distance from the internal pressure adjusting lid to be used. The magnetic flux Φ (Wb) at this time is defined as S _M (m ² ) where the cross-sectional area of the magnet ring 6 is S _M (m ² ).
Φ (Wb) = B _T · S _M
It becomes.

Here, when the magnet ring 6 forms a gap cross-sectional area of S _L (m ² ) with the opposing internal pressure adjustment lid through a member having a magnetic permeability μ, the magnetic attractive force F ₂ (N )
^{_{F 2 (N) = Φ 2}} /2 · μ · S L
It becomes.

Therefore, F ₂ (N) is expressed by equation (4).

F ₂ (N) = [{B ₀ + B ₀ · _Br · (T−23)} · S _M ] ² · μ · S _L / 2 (4)

When the electromagnetic relay is heated, F ₁ (N)> F ₂ (N) for the internal pressure adjusting lid 3 to operate at the temperature T (° C.) or higher due to the internal pressure. Since the temperature T (° C.) at this time varies depending on the specifications required for the electromagnetic relay, the magnet ring 6 having physical properties that can be operated at the temperature T (° C.) is selected. However, since the weight of the internal pressure adjustment lid 3 is not considered in this calculation process, it is necessary to incorporate its own weight into the calculation formula depending on the installation direction of the internal pressure adjustment lid 3.

  FIG. 3 is a view for explaining a second embodiment of the electromagnetic relay according to the present invention. FIG. 3 (a) is an exploded perspective view of the entire molded resin base 32 constituting this embodiment. 3B is an exploded perspective view of the internal pressure adjusting mechanism portion 42 formed on the molded resin base 32. FIG.

  The basic configuration of the electromagnetic relay of this embodiment is the same as that of the conventional electromagnetic relay shown in FIG. 6 except for the internal pressure adjusting mechanism portion 42 provided on the molded resin base 32. However, the through hole 5 of the molded resin cover 1 is a seal type shown in FIG.

  In the present embodiment, as shown in FIG. 3, the molded resin base 32 has an internal pressure adjusting mechanism portion 42. The basic structure of the internal pressure adjusting mechanism 2 is the same as that of the first embodiment. However, the through hole 5 is provided in a portion protruding outward from the bottom opposite to the mounting side of the electromagnetic drive unit of the molded resin base 32, and is molded in a portion where the sealing resin is not applied. The shape of the through hole 5, the shape of the recess 20 formed on the outer periphery thereof, the shape of the stopper, and the like are the same as in the first embodiment. The ring-shaped magnet ring 6 is fitted in accordance with the position of the magnet ring fitting claw 39 from the electromagnetic drive part mounting side of the molded resin base 32. The internal pressure adjusting lid 3 and the stopper are made of the same shape and material as in the first embodiment, and the internal pressure adjusting mechanism 42 is formed on the molded resin base 32 by following the same method for inserting the internal pressure adjusting lid 3 and the stopper into the recess 20. Thereby, the internal pressure adjusting mechanism 42 having the same function as that of the first embodiment and the same operation principle as that of FIG. 2 is obtained.

  FIG. 4 is a view for explaining a third embodiment of the electromagnetic relay according to the present invention, and FIG. 4 (a) shows an internal pressure adjusting mechanism 52 formed on the molded resin cover 31 constituting this embodiment. An exploded perspective view is shown, and FIG. 4B is a cross-sectional view of the internal pressure adjusting mechanism 52. The basic configuration of the electromagnetic relay of this embodiment is the same as that of the first embodiment except for the internal pressure adjustment mechanism 52 provided on the molded resin cover 31. In this embodiment, the return spring 13 is fixed to the side surface of the internal pressure adjustment lid 3, and the bottom surfaces of the internal pressure adjustment lid 3 and the recess 20 are pressed against the elastic ring 4 by the elastic force of the return spring 13.

  The molded resin cover 31 has the same shape as that of the first embodiment except that there is no magnet ring mounting portion. The internal pressure adjusting lid 3 uses a metal subjected to weathering and corrosion resistance plating. An elastic body provided on the lower surface in the insertion direction is welded to the internal pressure adjusting lid 3 with two or more metal plate return springs 13 that are hooked on a stopper 8 provided on the side surface of the recess 20 after insertion, at equal intervals around the circumference. The elastic ring 4 is fitted into the ring mounting groove 10. For the assembly, the inner pressure adjustment lid 3 is pushed into the recess 20, and at this time, the return spring 13 is inserted over the stopper 8, and after the insertion is completed, the bottom surface of the recess 20 of the molded resin cover 31 by the pressing force of the return spring 13, The elastic body ring 4 and the bottom surface of the internal pressure adjusting lid 3 are in close contact with each other.

  FIG. 4C is a cross-sectional view showing the shape of the return spring 13 welded to the internal pressure adjusting lid 3 and the positional relationship with the stopper 8 before and after assembly. The return spring 13 is attached at an acute angle with respect to the insertion direction, and an angle is also given to a portion that contacts the stopper 8. Therefore, it can be easily inserted, but once inserted, the structure is difficult to come off. The material of the return spring 13 is not limited as long as the function of the present invention can be obtained.

  FIG. 5 is a cross-sectional view showing the operating principle of the internal pressure adjusting mechanism 52 of this embodiment. When the electromagnetic relay is heated in a reflow process or the like, the internal pressure of the electromagnetic relay rises, the force overcomes the force of the return spring 13 at a certain temperature, and the internal pressure adjusting lid 3 is pushed up. Therefore, the gas inside the electromagnetic relay that has expanded from the through hole 5 passes and flows out. At this time, the internal pressure adjusting lid 3 is once pushed up, but when the internal pressure inside the electromagnetic relay decreases, the close contact with the molded resin cover 31 is instantaneously restored by the force of the return spring 13. When the temperature decreases, not only the pressing force of the return spring 13 but also the internal pressure of the electromagnetic relay decreases, so that the internal pressure adjusting lid 3 is pressed more firmly against the molded resin cover 31 and the airtight state is maintained.

In order to obtain the operating principle of FIG. 5, the relationship between the internal pressure of the electromagnetic relay applied during heating and the pressing force of the return spring 13 is controlled. When the area where the internal gas of the electromagnetic relay is in contact with the internal pressure adjusting lid 3 is S (m ² ) at the heating temperature T (° C.), the force F ₁ (N) applied to the internal pressure adjusting lid 3 is It can be obtained by the equation (2) shown. The return spring force F ₃ (N) is infinitely close to and not exceeding the internal pressure force F ₁ (N). However, since the weight of the internal pressure adjustment lid 3 is not considered in this calculation, it is necessary to incorporate its own weight into the calculation formula depending on the installation direction of the internal pressure adjustment lid 3.

  The basic configuration of the electromagnetic relay of the present embodiment is the same as that of the second embodiment except for the internal pressure adjusting mechanism provided on the molded resin base. However, in this embodiment, the return spring is fixed to the side surface of the internal pressure adjustment lid, and the bottom surface of the internal pressure adjustment lid and the recess is pressed against the elastic ring by the elastic force of the return spring.

  Also, the internal pressure adjusting mechanism part of this embodiment is molded in a portion where the molding resin-based sealing resin is not applied, and the through hole of the internal pressure adjusting mechanism part is from the bottom opposite to the mounting side of the electromagnetic driving part of the molded resin base. Although it is provided at a portion protruding outward, the basic structure of the internal pressure adjusting mechanism is the same as that of the third embodiment. The shape, material, shape of the internal pressure adjusting lid, the shape of the through hole, the concave portion formed in the outer peripheral portion thereof, and the stopper are the same as those in the third embodiment shown in FIG. By following the same method for inserting the internal pressure adjustment lid into the recess, the bottom surface of the recess of the molded resin base, the elastic ring, and the bottom surface of the internal pressure adjustment lid are brought into close contact with each other. Also in the present embodiment, an internal pressure adjusting mechanism having the same function as that of the third embodiment and the same operation principle as that of FIG. 5 is obtained.

  As described above, according to the present invention, it is possible to ensure stable airtightness even after a high-temperature heating process, and to prevent water and coating materials, and further, contamination gas from entering the inside of the electromagnetic relay. An electromagnetic relay with no obstacles is obtained.

  It goes without saying that the structure and installation position of the internal pressure adjusting mechanism used in the present invention are not limited to the above-described embodiments. The shape and material of the through hole, the internal pressure adjustment lid, the recess, the stopper, the magnet, and the like are only required to achieve the operation principle of the present invention, and various changes are possible. Further, in the above embodiment, in order to eliminate or reduce the portion protruding from the molded resin cover or the molded resin base after assembly, a recess is provided around the through hole, and the internal pressure adjustment lid can be accommodated therein. If there is little, the structure which does not provide a recessed part is also possible.

  By using the electromagnetic relay of the present invention, it becomes possible to mainly improve the reliability of automobile parts and electrical parts, but in other industrial fields, by using the present invention for electromagnetic relays for measuring instruments, It is also possible to improve the reliability of contact.

FIG. 1A is an exploded perspective view of the entire molded resin cover, and FIG. 1B is an internal pressure adjusting mechanism formed on the molded resin cover. FIG. 1C is a sectional view of the internal pressure adjusting mechanism. Sectional drawing which shows the principle of operation of the internal pressure adjustment mechanism part of a 1st Example. The figure for demonstrating the 2nd Example of the electromagnetic relay by this invention, Fig.3 (a) is a disassembled perspective view of the whole molding resin base which comprises this Example, FIG.3 (b) is a molding resin base The disassembled perspective view of the formed internal pressure adjustment mechanism part. FIG. 4A is an exploded perspective view of an internal pressure adjusting mechanism formed on a molded resin cover constituting this embodiment, and FIG. 4B is a view for explaining a third embodiment of the electromagnetic relay according to the present invention. ) Is an exploded perspective view of the internal pressure adjusting mechanism, and FIG. 4C is a cross-sectional view showing the shape of the return spring welded to the internal pressure adjusting lid and the positional relationship with the stopper before and after assembly. Sectional drawing which shows the principle of operation of the internal pressure adjustment mechanism part of a 3rd Example. The disassembled perspective view of the conventional common electromagnetic relay. FIG. 7A is an unsealed (non-sealed) type through-hole structure, and FIG. 7B is a sealed (sealed) type through-hole structure for explaining the structure of a through-hole portion of a conventional molded resin cover. The figure which shows a hole structure.

Explanation of symbols

1, 21, 31 Molded resin cover 2, 42, 52 Internal pressure adjusting mechanism 20 Recess 3 Internal pressure adjusting lid 4 Elastic ring 5, 5a, 5b Through hole 6 Magnet ring 7 Return stopper 8 Stopper 9, 39 Magnet ring fitting claw DESCRIPTION OF SYMBOLS 10 Elastic body ring installation groove | channel 11 Trap stage 12, 32 Molding resin base 13 Return spring 14 Electromagnetic drive part 15 Sealing resin

Claims (6)

  Consists of a main body portion that includes an electrical contact portion, an electromagnetic drive portion, and a molded resin base, and a molded resin cover that covers the main body portion, and constitutes the molded resin base and the electrical contact portion or part of the electromagnetic drive portion. In an electromagnetic relay in which the gap between the terminal and the gap between the main body and the molded resin cover is sealed with a sealing resin, an internal pressure adjusting mechanism is provided on at least one of the molded resin cover or the molded resin base. The internal pressure adjusting mechanism includes an air vent through hole, an internal pressure adjusting lid that covers the through hole, and an elastic ring installed on an outer periphery of the through hole, and the internal pressure adjusting lid and the through hole The electromagnetic relay is characterized in that an outer peripheral portion of the magnet is crimped to the elastic ring by an attractive force by a magnet or an elastic force by a spring.   The through hole is a hole provided in a protruding portion of the molded resin cover that extends toward the outside of the molded resin cover. The through hole has a recess in the outer peripheral portion of the through hole, and the internal pressure adjustment lid is in the recess. It is made of a magnetic metal having an outer shape to be fitted, and the elastic ring is attached to a portion of the internal pressure adjusting lid that faces the bottom surface of the concave portion, and a portion that faces the concave portion inside the molded resin cover. A magnet ring that is fitted, covers the through-hole by pushing and inserting the internal pressure adjustment lid into the recess, and the internal pressure adjustment lid and the magnetic pressure adjustment force by the magnetic pressure force between the internal pressure adjustment lid and the magnet ring; The electromagnetic relay according to claim 1, wherein a bottom surface of the concave portion is crimped to the elastic ring.   The through hole is a hole provided in a protruding portion formed in the molded resin base and directed toward the outside of the molded resin base. The through hole has a concave portion on an outer peripheral portion of the through hole, and the internal pressure adjusting lid is formed on the concave portion. It is made of a magnetic metal having an outer shape to be fitted, and the elastic ring is attached to a portion facing the bottom surface of the concave portion of the internal pressure adjusting lid, and on a portion facing the concave portion inside the molded resin base A magnet ring that is fitted, covers the through-hole by pushing and inserting the internal pressure adjustment lid into the recess, and the internal pressure adjustment lid and the magnetic pressure adjustment force by the magnetic pressure force between the internal pressure adjustment lid and the magnet ring; The electromagnetic relay according to claim 1, wherein a bottom surface of the concave portion is crimped to the elastic ring.   Protrusions are provided on the side surfaces of the recesses on the outer peripheral portion of the through hole and the side surfaces of the internal pressure adjustment lid, respectively, so that the projections on the side surfaces of the internal pressure adjustment lid are located inside the projections on the side surfaces of the recesses. 4. The electromagnetic relay according to claim 2, wherein the internal pressure adjustment lid is inserted into the recess, and the displacement amount of the internal pressure adjustment lid is limited by the two protrusions. 5.   The through hole is a hole provided in a protruding portion of the molded resin cover that extends toward the outside of the molded resin cover. The through hole has a recess in the outer peripheral portion of the through hole, and the internal pressure adjustment lid is in the recess. The elastic ring is attached to a portion of the internal pressure adjustment lid facing the bottom surface of the recess, a return spring is fixed to a side surface of the internal pressure adjustment lid, and an outer peripheral portion of the through hole is formed. Protruding portions are provided on the side surfaces of the recesses, the inner pressure adjustment lid is pushed into the recesses and inserted so that the tip of the return spring is located inside the protrusions on the side surfaces of the recesses, and the through holes are covered; and The electromagnetic relay according to claim 1, wherein the inner pressure adjusting lid and the bottom surface of the recess are pressed against the elastic ring by an elastic force of the return spring.   The through hole is a hole provided in a protruding portion formed in the molded resin base and directed toward the outside of the molded resin base. The through hole has a concave portion on an outer peripheral portion of the through hole, and the internal pressure adjusting lid is formed on the concave portion. The elastic ring is attached to a portion of the internal pressure adjustment lid facing the bottom surface of the recess, a return spring is fixed to a side surface of the internal pressure adjustment lid, and an outer peripheral portion of the through hole is formed. Protruding portions are provided on the side surfaces of the recesses, the inner pressure adjustment lid is pushed into the recesses and inserted so that the tip of the return spring is located inside the protrusions on the side surfaces of the recesses, and the through holes are covered; and The electromagnetic relay according to claim 1, wherein the inner pressure adjusting lid and the bottom surface of the recess are pressed against the elastic ring by an elastic force of the return spring.

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