JP2009076364A - Electromagnetic relay - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnetic relay having a filter part which can maintain stable breathability even under a severe reflow heating condition. <P>SOLUTION: The electromagnetic relay having a resin cover 11 in which a through hole 12 for deflation is formed is provided with a filter part 6 made of quartz wool which has breathability and water resistance in the middle of the through hole. <P>COPYRIGHT: (C)2009,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.

  FIG. 4 is an exploded perspective view of a conventional general electromagnetic relay. 5 is a longitudinal sectional view for explaining the structure of the through hole of the molded resin cover of the electromagnetic relay shown in FIG. 4. FIG. 5 (a) Unsealed (non-sealed) type through hole structure, FIG. Indicates a seal (sealing) type through-hole structure.

  As shown on the left side of FIG. 4, the conventional electromagnetic relay includes a molded resin cover 1 in which a through hole 2 is formed, an electromagnetic drive unit 3 that holds an electrical contact portion, and a molded resin base 4. The electromagnetic drive unit 3 is mounted on a molded resin base 4 to constitute a main body, and the entire main body is covered with the molded resin cover 1. Further, the gap between the terminal of the electromagnetic drive unit 3 inserted into the hole formed in the molded resin base 4 and the molded resin base 4 and the gap between the main body and the molded resin cover 1 are as shown on the right side of FIG. And sealing with resin 5 for sealing.

  As shown in FIGS. 4 and 5, the top surface of the molded resin cover 1 is provided with a protruding portion that protrudes outward, and a through hole 2 that penetrates the protruding portion is formed. The molded resin cover 1 is commonly used for an unsealed electromagnetic relay and a sealed electromagnetic relay. When used in an unsealed electromagnetic relay, as shown in FIG. 5 (a), the protrusions are not processed and the through holes 2a are left as they are. On the other hand, when used in a seal-type electromagnetic relay, as shown in FIG. 5B, the protrusion is melted by heat caulking to close the through hole 2b. As described above, since the molded resin cover 1 is also commonly used for a seal-type electromagnetic relay, the protrusions and the through holes 2 formed on the top surface are shaped in consideration of moldability and heat caulking workability. The hole diameter is determined.

  Usually, an unseal type electromagnetic relay is used when it is assumed that a large thermal stress is received by a reflow heating process or the like. This is because the seal-type electromagnetic relay is in a state in which the electromagnetic drive unit is completely sealed from the outside and the escape path of the internal gas is closed, and there is a possibility that hermetic failure may occur due to thermal stress such as a reflow heating process. Because there is.

  However, the unsealed electromagnetic relay is not suitable for in-vehicle use. This is because in the case of in-vehicle use, after the electromagnetic relay is mounted on the printed board by the reflow heating process, the coating agent may be applied to the entire printed board. In this case, if the coating agent enters the electromagnetic relay from the through hole 2, there is a risk of causing an operation failure or a contact contact failure. Moreover, in order to remove the residue of the flux at the time of solder connection, the electromagnetic relay may be immersed in a cleaning solution together with the printed circuit board and may be washed. Also in this case, if the cleaning agent enters the electromagnetic relay from the through hole 2, there is a risk of causing an operation failure or a contact contact failure. Therefore, as an in-vehicle electromagnetic relay, a seal type is generally used in order to ensure reliability.

  In a seal-type electromagnetic relay, a sealing structure is strengthened so that airtight destruction does not occur even by thermal stress in the reflow heating process. For example, in the electromagnetic relay of FIG. 4, the sealing resin 5 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 4 to increase the airtightness. Is done.

  On the other hand, as a conventional electromagnetic relay that prevents hermetic breakage due to heating and enables immersion in a cleaning solution, etc., a filter part made of a continuous porous material that has both water resistance and air permeability in part of the outer shell of the housing (For example, refer to Patent Document 1). An example of the continuous porous material is Gore-Tex (registered trademark) (PTFE (polytetrafluoroethylene) having a continuous porous structure) manufactured by Japan Gore-Tex Co., Ltd.

  Moreover, as an electromagnetic relay having a similar structure, there is one in which a porous film having air permeability is formed in an air hole portion formed in a case (see, for example, Patent Document 2).

JP-A-5-242784 JP-A-11-145667

  A seal type electromagnetic relay has a limit point that causes hermetic failure when the internal gas is thermally expanded by heating. This limit can be raised by a technique for improving the heat resistance and adhesive strength of the sealing resin.

  However, the hermetic breakage occurs at a portion where the adhesive strength of the sealing resin is the weakest. Moreover, the adhesive properties of the sealing resin are likely to change depending on the application conditions, thermosetting conditions, or external conditions such as ambient temperature and humidity, and it is difficult to control the adhesive strength to be kept completely constant in the manufacturing process. It is. Therefore, it is difficult to maintain the airtightness of the electromagnetic relay under more severe reflow heating conditions even by a technique for increasing the heat resistance and adhesive strength of the sealing resin.

  On the other hand, in the electromagnetic relay described in Patent Documents 1 and 2, since the housing and the like are provided with a filter part and a film having air permeability, there is no fear of the hermetic breakdown as described above.

  However, the filter part described in the cited document 1 is made of, for example, Gore-Tex, and has a lower heat resistance limit than a liquid crystal polymer usually used as a molded resin base (housing). Therefore, there is a problem that it is difficult to maintain the porosity even within the heat resistance limit of the molded resin base under more severe reflow heating conditions as in the case of using leadless solder or the like. .

  Similarly, the coating described in Reference 2 is soluble in the photopolymerizable monomer, the substance that is incompatible with the photopolymerizable monomer, and both the photopolymerizable monomer and the incompatible substance. A liquid consisting of a solvent and a photopolymerization initiator for curing a photopolymerizable monomer by electromagnetic wave irradiation is cured by ultraviolet irradiation. There is a problem that it is difficult to maintain quality.

  Furthermore, the coating described in the cited document 2 has a problem that it is difficult to realize uniform characteristics, such as that the raw material is a liquid and that it must be applied to the air holes, and the productivity is low. is there.

  In view of the above problems, the present invention provides an easy-to-manufacture electromagnetic relay capable of maintaining stable air permeability even under more severe heating conditions and preventing internal entry of water or a coating agent. The purpose is to provide.

  In order to achieve the above object, an electromagnetic relay according to the present invention is an electromagnetic relay having a resin cover in which a through hole for venting air is formed. The quartz wool has air permeability and water resistance in the middle of the through hole. The filter part which consists of is provided.

  Specifically, in the electromagnetic relay, the resin cover has a hollow protrusion having an inner peripheral surface defining a part of the through hole, the filter portion is accommodated in the protrusion, and the The tip of the protrusion is fixed by caulking the heat.

  According to the present invention, by providing the filter portion made of quartz wool in the middle of the air vent through hole, it is possible to ensure stable air permeability even under more severe reflow conditions, It is possible to provide an electromagnetic relay capable of preventing the cleaning agent or the coating agent from entering the coating agent during application.

  Since the filter part is accommodated in the protruding part and fixed by heat caulking the protruding part, the manufacturing process is simple.

  Embodiments of an electromagnetic relay according to the present invention will be described below with reference to the drawings. In addition, this invention is not limited to a following example. Furthermore, the present invention includes modifications within a range not departing from the gist of the present invention.

  FIG. 1 is a view for explaining a first embodiment of an electromagnetic relay according to the present invention. FIG. 1A is an exploded perspective view of a molded resin cover 11 and a filter unit 6 used in this embodiment. FIG. 1B is a partially enlarged view around the through hole 12 formed in the molded resin cover 11, and FIG. 1C is a partial cross-sectional view of the molded resin cover 11 for explaining the peripheral structure of the through hole 12. is there.

  The electromagnetic relay of this embodiment has the same basic structure as the conventional electromagnetic relay shown in FIG. 4 except for the filter portion 6 provided on the molded resin cover 11. More specifically, the electromagnetic relay according to the present embodiment includes a main body provided with an electromagnetic drive unit (3 in FIG. 4) and a molded resin base (4 in FIG. 4) holding an electric contact part, and a molding that covers the main body unit. The resin cover 11 includes a gap between a terminal or the like inserted into a hole formed in the molded resin base and the molded resin base and a gap between the main body and the molded resin cover 11 (see FIG. 4). 5).

  As shown in FIGS. 1B and 1C, the molded resin cover 11 has a protrusion 22 that protrudes outward in a recess 21 provided on the top surface. Further, the molded resin cover 11 has another protrusion 23 that protrudes inward at a position corresponding to the protrusion 22. And the through-hole 12 is formed so that these protrusion parts 22 and 23 may be penetrated together. In other words, the inner peripheral surfaces of the hollow protrusions 22 and 23 define the through hole 12.

  The inner diameter of the through hole 12 is different between a portion corresponding to the protrusion 22 and a portion corresponding to the protrusion 23. As a result, the through hole 12 has a step near the center. This step is used as a part of the holding part 7 that holds the filter part 6.

  The filter unit 6 is made of quartz wool and is inserted into the protrusion 23 from the inside of the molded resin cover 11. The protruding portion 23 is deformed by the subsequent heat caulking, and the filter portion 6 is fixed to the molded resin cover 11.

  FIG. 1C shows a cross section of the through hole 12 after the filter unit 6 is fixed to the molded resin cover 11. The filter portion 6 made of quartz wool is fixed to the holding portion 7 provided on the molded resin cover 11 by heat caulking from the inside of the molded resin cover 11, so that the penetration is formed in the stepped portion in a compressed state. The opening of the hole 12 is completely covered.

The quartz wool used in this example has a wire diameter of 4 to 6 μm. Since the filter portion 6 fixed to the molded resin cover 11 is compressed by fixing by heat caulking, a porous state having a pore diameter of several μm due to fine fibers is obtained. Specifically, since the specific gravity of quartz glass, which is a raw material of quartz wool, is 2.2 g / cm ³ , in this embodiment, the volume of the filter portion 6 with 10 mg of quartz wool is 9.1 mm ³ after fixing. Therefore, the quartz glass occupies 50% of the entire filter unit 6. Since quartz wool is characterized in that the fiber thickness is constant, the filter unit 6 can realize a porous state having a fine pore diameter of about 5 μm, which is equivalent to the wire diameter of quartz wool. Therefore, the filter unit 6 has high air permeability and can prevent water or a coating agent from entering the electromagnetic relay.

  Next, with reference to FIG. 2, the adhering method of the filter part 6 in a present Example is demonstrated.

  2A is a partial cross-sectional view of the molded resin cover 11 before the filter unit 6 used in this embodiment is fixed, and FIG. 2B is a diagram illustrating the filter unit 6 fixed to the holding unit 7 by heat caulking. FIG.

  As shown in FIG. 2A, the quartz wool that becomes the filter portion 6 from above is placed in the protruding portion 23 of the molded resin cover 11, that is, the holding portion 7 so that the inside of the molded resin cover 11 faces upward. Stuff. Thereafter, the protrusion 23 is deformed by heat caulking, and the filter unit 6 is fixed to the holding unit 7. At this time, as shown in FIG. 2B, the protrusion 23 is melted so as not to completely close the ventilation portion. In this embodiment, in order to prevent complete sealing of the ventilation portion, a heat caulking iron 8 having a pin 9 at the center of its tip is used.

  According to the present embodiment, the through hole 12 of the molded resin cover 11 has high air permeability. Here, the resin used for the molded resin cover 11 is a resin that is generally used for electromagnetic relays, but has high heat resistance, so reflow heating (leading temperature: 250 to 300 ° C.) of about the lead-less solder melting condition. ) Does not change the shape of the through hole due to heat. Moreover, in the filter part 6 using quartz wool, since quartz wool has a very high heat resistance with a shrinkage rate of 0% even at 1000 ° C. for 1 hour, the performance of the filter part is also achieved by reflow heating under lead-less solder melting conditions. Will not change.

  In the electromagnetic relay of the present embodiment, the filter part has both air permeability and water resistance, and also has high heat resistance, so that the cleaning agent and the coating agent do not enter inside due to hermetic failure due to thermal stress. Therefore, the electromagnetic relay of the present embodiment does not have an operation failure or a contact failure due to foreign matter entry.

  Further, since the quartz wool is simply inserted into the protrusion 23 of the molded resin cover 11 and the protrusion 23 is caulked by heat, the manufacturing process is simple.

  Further, the molded resin cover 11 of this embodiment can be used for a seal type electromagnetic relay because the vent portion can be easily completely closed by heat caulking the protrusion 22.

  Next, a second embodiment of the present invention will be described with reference to FIG.

  3A is an exploded perspective view of the molded resin cover 31 and the filter unit 6 used in this embodiment, and FIG. 3B is a partially enlarged perspective view around the through hole 32 formed in the molded resin cover 31. is there.

  The electromagnetic relay of this embodiment is the same as that of the first embodiment except for the protrusions 33 and 34 provided on the molded resin cover 31, and the basic fixing method of the filter portion 6 is also the same as that of the first embodiment. .

  In this embodiment, the inner diameter of the protrusion 33 protruding outward is larger than the inner diameter of the protrusion 34 protruding inward. Therefore, the holding part 7 that uses the step in the center of the through hole 32 formed so as to penetrate the protrusions 33 and 34 opens toward the outside of the molded resin cover 31. Therefore, the quartz wool that becomes the filter portion 6 is packed into the holding portion 7 from the outside of the molded resin cover 31. Thereafter, when the protruding portion 33 is deformed by heat caulking, the filter portion 6 is fixed to the holding portion 7.

  Also according to the present embodiment, the filter unit 6 having the same performance as that of the first embodiment can be obtained. In this embodiment, since the quartz wool can be packed from the outside of the molded resin cover 31 and the protrusion 33 can be heat-caulked, the gap between the molded resin cover 31 and the molded resin base (4 in FIG. 4) is sealed. After sealing with the resin for use (5 in FIG. 4), the filter unit 6 can be fixed.

  In the electromagnetic relay of this embodiment, the filter part has both air permeability and water resistance, and also has high heat resistance, so that the cleaning agent and the coating agent do not enter the inside due to the hermetic breakage due to thermal stress. Therefore, the electromagnetic relay according to the present embodiment also has no operation failure or contact failure due to the entry of foreign matter. Moreover, the manufacturing process is simple.

  As mentioned above, although this invention was demonstrated according to two Examples, this invention is not limited to the said Example. For example, it goes without saying that the structure, shape, size, and installation position of the protrusion (or the through hole) are not limited to the above-described embodiments. Further, the shape and material of the through hole, the filter part, and the holding part are only required to achieve the principle of the present invention, and various changes can be made.

  By using the electromagnetic relay of the present invention, it is possible to mainly improve the reliability of automobile parts and electrical parts. Furthermore, in other industrial fields, the contact contact reliability can be improved by using the electromagnetic relay for measuring instruments.

(A) is an exploded perspective view of a molded resin cover and a filter portion used in the electromagnetic relay according to the first embodiment of the present invention, (b) is a partially enlarged perspective view around the through hole of the molded resin cover, and ( c) is a partial cross-sectional view of a molded resin cover for explaining a structure around a through hole. FIG. 2A is a partial cross-sectional view of the molded resin cover 11 showing a state before the filter unit 6 used in the first embodiment is fixed, and FIG. It is a fragmentary sectional view of the molding resin cover 11 which shows the state after the part 6 was fixed. (A) is a disassembled perspective view of the molded resin cover and filter part used in the electromagnetic relay according to the second embodiment of the present invention, and (b) is a partially enlarged perspective view of the periphery of the through hole of the molded resin cover. . It is a disassembled perspective view of a general electromagnetic relay. (A) is sectional drawing which shows the through-hole structure of an unsealed (non-sealing) type molded resin cover, (b) is sectional drawing which shows the through-hole structure of a sealing (sealing) type molded resin cover.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,11,31 Molded resin cover 2,12,32 Through-hole 3 Electromagnetic drive part 4 Molded resin base 5 Sealing resin 6 Filter part 7 Holding part 8 Heat caulking iron 21 Recess 22, 23, 33, 34 protrusion

Claims (6)

In an electromagnetic relay having a resin cover in which a through hole for venting air is formed,
An electromagnetic relay comprising a filter portion made of quartz wool having air permeability and water resistance in the middle of the through hole. The resin cover has a hollow protrusion having an inner peripheral surface defining a part of the through hole;
2. The electromagnetic relay according to claim 1, wherein the filter part is accommodated in the protrusion part and fixed by heat caulking the tip part of the protrusion part.   The electromagnetic relay according to claim 2, wherein the protrusion protrudes toward the inside of the resin cover.   4. The resin cover according to claim 3, wherein the resin cover has an inner peripheral surface that defines the remaining portion of the through hole and another protrusion protruding toward the outside of the resin cover. The electromagnetic relay described.   The electromagnetic relay according to claim 2, wherein the protrusion protrudes toward the outside of the resin cover.   A main body portion including an electrical contact portion, an electromagnetic drive portion, and a molded resin base is provided, and a gap between the molded resin base and a terminal constituting a part of the electrical contact portion or the electromagnetic drive portion is a sealing resin. The electromagnetic relay according to any one of claims 1 to 5, wherein the electromagnetic relay is sealed.

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