Electromagnetic relay

Abstract

A housing (10) has a flame-extinguishing opening (50) that connects a storage compartment (104) to an outside and extinguishes a flame. A sealing element (60) covers the flame-extinguishing opening to make the storage compartment a sealed space and prevent the ingress of gas from the outside into the interior of the storage compartment. A moisture-absorbing element (70) is provided in the storage compartment and absorbs water vapor within the storage compartment.

Description

Cross-Reference to Related ApplicationThis application is based on Japanese Patent Application No. 2023-030225 filed on Feb. 28, 2023, the contents of which are incorporated herein by reference.Technical FieldThe present disclosure relates to an electromagnetic relay for opening and closing an electric circuit.BackgroundConventional electromagnetic relays as shown in Patent Literature 1 have a structure including a housing having a receiving space that is open to the outside through an opening, and a base that fits into the housing and closes the opening. The accommodating space is connected to the outside through a ventilation hole formed in the housing or at the part between the housing and the base. By the presence of this vent, any flame generated in the receiving space is extinguished when passing through the vent, because the flame loses heat to the base and the ports.In addition, as shown in Patent Literature 2, in order to prevent siloxane gas from entering the inside of a microswitch, a rubber cap is mounted on the sliding part of the push button fixed to the housing, the surface of which is coated with a gas barrier layer.Literature in the Prior ArtPatent LiteraturePatent Literature 1: JP 2017-084613 APatent Literature 2: JP 2009-059523 ASummary of the InventionHowever, as shown in Patent Literature 1, in the construction in which the inside and the outside of the housing are connected through the ventilation opening, the siloxane gas may enter the accommodation space through the ventilation opening, although flame extinguishing is possible when an electromagnetic relay is used in an environment in which siloxane gas may be generated. Therefore, there is a possibility that the contact conductivity is deteriorated by the influence of the siloxane gas.On the other hand, by the coating with a gas barrier layer making the accommodation space inside the housing a sealed space, it is conceivable to suppress the introduction of siloxane gas from the outside into the accommodation space as shown in Patent Literature 2. However, if the accommodation space is made a sealed space, the escape of water vapor evaporated from internal components and the like inside the accommodation space to the outside of the housing is obstructed. Therefore, the water vapor may freeze in environments with minus degrees on the contact surfaces, which may result in poor contact conductivity.An object of the present disclosure is to provide an electromagnetic relay capable of extinguishing flames inside a housing space and suppressing poor contact conductivity caused by the influence of siloxane gas and water vapor inside the housing space.An electromagnetic relay according to a first aspect of the present disclosure includes a housing, a base, a coil, a pair of fixed contact devices, a movable contact device, a sealing member, and a moisture absorbing member. The housing has a receiving space which is open to the outside through an opening. The base is inserted into the housing and closes the opening. The coil is disposed in the accommodation space and configured to generate an electromagnetic force upon energization. The pair of fixed contact means each has an end disposed in the accommodating space and fixed to the base. The movable contact device is disposed in the accommodating space and is configured to be driven by the electromagnetic force generated by the coil to make or break contact with the pair of fixed contact devices. The housing or base has a flame extinguishing opening configured to extinguish a flame. The receiving space is connected to the outside world through the flame extinguishing opening. The sealing member covers the flame extinguishing hole to make the accommodation space a sealed space and prevent gas from entering the interior of the accommodation space from the outside. The moisture absorbing member is disposed in the accommodation space to absorb water vapor inside the accommodation space.In this way, by covering the flame extinguishing hole with the sealing member, the invasion of siloxane gas or flammable gas can be suppressed even in environments where siloxane gas or flammable gas is present around the electromagnetic relay. Therefore, it is possible to suppress poor contact caused by the influence of siloxane gas and reduce the possibility of ignition of combustible gas. Since the flame extinguishing hole is provided, the flames can be extinguished even if flammable gas is present in the accommodating space and the flammable gas ignites and generates flames because they lose heat when entering the flame extinguishing hole, thereby preventing flame propagation. Therefore, the flames can be prevented from spreading to the outside of the electromagnetic relay.Since the accommodation space is sealed by the sealing member as a closed space, the water vapor, if generated inside the accommodation space, cannot leak to the outside. However, since the moisture absorbing member is provided inside the accommodating space, the moisture absorbing member can absorb the water vapor. Therefore, even in environments with temperatures below freezing, the moisture absorbing member prevents the freezing of water vapor and hence poor contact conductivity.According to a second aspect of the present disclosure, the sealing member is a gas barrier layer that is attached to the housing or the base having the flame extinguishing opening and covers the flame extinguishing opening.In this way, the sealing element can be formed by the gas barrier layer and can cover the flame extinguishing opening by attachment to the housing or to the base where the flame extinguishing opening is formed.According to a third aspect of the present disclosure, the sealing member has a bottomed cylindrical shape having a hollow portion, and has an internal thread formed on an inner wall surface defining the hollow portion. The housing or base having the flame extinguishing opening has a support wall around the flame extinguishing opening, and the support wall has an external thread corresponding to the internal thread. The sealing member is fixed to the support wall via the male thread and the female thread, and the flame extinguishing hole is covered by the sealing member.In this way, the sealing member has a cylindrical bottom shape with internal threads, and the support wall with external threads is formed around the flame extinguishing opening. Thus, the sealing element can be fastened to the carrier wall by screwing in, whereby the flame extinguishing opening is covered with the sealing element.According to a fourth aspect of the present disclosure, the moisture absorbing member is a moisture absorbing material applied to the wall surfaces of the housing and the base defining the accommodation space.In this way, the moisture absorbing member can be provided by applying the moisture absorbing material to the wall surfaces of the housing and the base defining the accommodation space. Accordingly, it becomes unnecessary to ensure additional space that would be required if the moisture absorbing member were a separate component.According to a fifth aspect of the present disclosure, the moisture absorbing member is a moisture absorbing material applied to the inner wall surfaces of the housing and the base defining the accommodation space. The moisture absorbing material is not contained in a portion of the inner wall surfaces surrounding a contact portion including a fixed contact of the fixed contact means and a movable contact of the movable contact means. The moisture absorbing material is provided in a portion of the inner wall surfaces that surrounds the coil and is different from the portion surrounding the contact portion [Thus, in the accommodating space, a region in which the moisture absorption member is disposed and a region in which the moisture absorption member is not disposed may be provided. When water vapor is generated inside the accommodation space, it is possible to generate a high water vapor concentration region and a low water vapor concentration region. As a result, a water vapor concentration gradient forms within the receiving space, which enables the water vapor to diffuse from the region with higher concentration to the region with lower concentration. Therefore, the retention of water vapor in the vicinity of the contact portion can be prevented. Consequently, even in environments with temperatures below freezing, formation of ice of water vapor is prevented, thereby suppressing poor contact conduction. [A reference sign in parentheses assigned to each component, etc., indicates an example of the correspondence between each component and a specific component described in the embodiments mentioned later.Brief Description of the DrawingsFIG. 1 is a cross-sectional view illustrating an electromagnetic relay according to a first embodiment. FIG. 2 is a view taken in the direction of arrow II of FIG. 1. FIG. 3 is a cross-sectional view taken along line III-III of FIG. 1. FIG. 4 is a perspective view of the electromagnetic relay illustrated in FIGS. 1, 2 to 3. FIG. 5 is a partial cross-sectional view of a portion of the housing taken along line V-V of FIG. 4. FIG. 6 is a cross-sectional view illustrating an electromagnetic relay according to a second embodiment. FIG. 7 is a cross-sectional view taken along line VII-VII of FIG. 6. FIG. 8 is a partial cross-sectional view of a portion of a housing in an electromagnetic relay according to a third embodiment.Embodiments for Realizing the InventionThe embodiments of the present disclosure will be described below with reference to the drawings. In the following embodiments, parts identical or equivalent to those described in the preceding embodiments are denoted by the same reference numerals, and descriptions thereof may be omitted. In addition, in each embodiment, when only a part of the components is described, the components described in the foregoing embodiments may be applied to the other parts of the components.First EmbodimentAn electromagnetic relay according to the present embodiment is used in, for example, an electric vehicle equipped with a fuel cell. The fuel cell is an electric generator that uses hydrogen gas, which is a combustible gas.As shown in FIGS. 1, 2, 3, 4 to 5, the electromagnetic relay according to the present embodiment includes a housing 10 made of resin. The housing 10 has four side walls 101 and a housing bottom 102, and a housing opening 103 forming a bottomed quadrangular tubular shape is provided on a surface opposite to the housing bottom 102. An accommodation space 104 is formed inside the housing 10, and this accommodation space 104 is open to the outside through the opening 103 of the housing.A base 12 made of resin includes a base bottom 121 that fits into the housing 10 and closes the opening 103 of the housing, a base body 122 that protrudes from the base bottom 121 toward the housing bottom 102, and a base spring seat 123 that holds a contact pressure spring 38 to be described later. The accommodation space 104 is defined by the housing 10 and the base bottom 121. The base 12 is formed by injection molding using a pair of stators 14 described later as inserts.As shown in FIG. 2, the bottom of the base 121 has two insertion holes 124 into which a pair of coil terminals 20 described later are inserted.In assembling the base 12 to the housing 10, the base 12 is inserted into the housing 10 by moving the base 12 relative to the housing 10 from the right side to the left side in FIG. 1, as indicated by the arrow X. Hereinafter, the insertion direction of the base 12 when assembling the base 12 to the housing 10 will be referred to as a base insertion direction X.As shown in FIG. 3, the two stators 14 made of conductive metal plates are fixed to the base 12. Each stator 14 has one end fixed to the base body 122 and located inside the accommodation space 104, while the other end of each stator 14 protrudes outward. A fixed contact 16 made of conductive metal is riveted and fixed to the end of a stator 14 protruding into the accommodation space 104. The other end of the stator 14 protruding outward is connected to an external electric circuit (not shown). The stator 14 and the fixed contact 16 together constitute a fixed contact means.In the accommodation space 104, a cylindrical coil 18 that generates an electromagnetic force when energized is disposed. The pair of conductive metal coil terminals 20 are connected to this coil 18.The coil terminals 20 are inserted into the insertion holes 124 with their ends protruding from the electromagnetic relay. More specifically, the coil terminals 20 are press-fitted into the terminal insertion holes 124, thereby ensuring that there is no gap between the coil terminals 20 and the inner wall surfaces defining the terminal insertion holes 124. The coil terminals 20 are connected to a controller (not shown) via an external terminal, and the coil 18 is energized via this external terminal and the coil terminals 20.Between the coil 18 and the base body 122, a disk-shaped plate 22 made of ferromagnetic metal material is disposed. A yoke 24 made of ferromagnetic metal material is arranged next to the side of the coil 18 facing away from the base body 122 and along the outer periphery of the coil 18. The plate 22 and the yoke 24 are fixed to the base 12.In the inner circumferential space of the coil 18 is disposed a cylindrical fixed core 26 of ferromagnetic metal material held by the yoke 24.A disc-shaped movable core 28 made of ferromagnetic metal material is disposed between the base body 122 and the plate 22. In addition, a return spring 30 is disposed between the coil 18 and the movable core 28 to bias the movable core 28 in a direction away from the fixed core 26.When the coil 18 is energized, the electromagnetic force generated by the coil 18 causes the movable core 28 to be attracted toward the fixed core 26 against the return spring 30. The plate 22, the yoke 24, the fixed core 26, and the movable core 28 form the magnetic path for the magnetic flux induced from the coil 18.A metal shaft 32 passes through and is fixed to the movable core 28. One end of the shaft 32 extends in a direction away from the fixed core 26, and the end of this one end of the shaft 32 is fitted and fixed in an insulating bush 34 made of resin having excellent electrical insulating properties. The other end of the shaft 32 is slidably inserted into the fixed core 26.In the accommodation space 104, a mover 36 made of a conductive metal plate is disposed. Between the moving device 36 and the base spring seat 123, the contact pressure spring 38 is arranged to bias the moving device 36 toward the insulating bush 34. Two movable contacts 40 made of conductive metal are riveted and fixed to the moving device 36 at positions opposing the two fixed contacts 16. The moving means 36 and the movable contacts 40 constitute a movable contact means.In the recess of the base body 122, a pair of permanent magnets 42 are disposed to form a magnetic field in the contact separation regions where the fixed contacts 16 and the movable contacts 40 make and break contact, thereby expanding the arc generated between the fixed contacts 16 and the movable contacts 40. These permanent magnets 42 are disposed opposite to each other along the alignment direction of the pair of contact separation regions (the left-right direction in FIG. 3 ).In addition, as shown in FIGS. 4 and 5, a flame extinguishing hole 50 is formed in the housing 10, and a sealing member 60 is disposed to cover the flame extinguishing hole 50. Although it is possible to provide a structure in which the accommodation space 104 is sealed only by the housing 10 and the base 12 without forming a flame extinguishing opening 50 in the housing 10, this would require the housing 10 and the base 12 to be made of metal or ceramic and welded, thereby reducing flexibility in material selection and manufacturing processes. Therefore, a construction is adopted here in which the flame extinguishing hole 50 is provided in the housing 10. By covering the flame extinguishing hole 50 with the sealing member 60, the accommodation space 104 is sealed.The flame extinguishing hole 50 connects the accommodation space 104 (see FIG. 1 ) to the outside, and in this embodiment, the flame extinguishing hole 50 is provided in the housing 10. More specifically, the flame extinguishing hole 50 is an elongated rectangular slit penetrating through the side wall 101 of the housing 10. The short-side dimension S of the flame extinguishing hole 50 is set so that the flame entering the flame extinguishing hole 50 can be extinguished. For example, the width of the slit forming the flame extinguishing hole 50 may be set to 0.3 mm or less.The flame extinguishing opening 50 may also be formed in the base 12 or provided as a groove at the contact surface between the housing 10 and the base 12. However, when the flame extinguishing hole 50 is formed in the housing 10 as in the present embodiment, the position of the flame extinguishing hole 50 can be set without being restricted by the position of the insertion holes of the terminal 124 as shown in FIG. 2, thereby improving the flexibility of the construction. In addition, since the dimensions of the flame extinguishing hole 50 can be adjusted independently of the width dimensions of the coil terminals 20, it is easy to ensure the function of extinguishing the flame and secure the predetermined passage area.Moreover, the sealing member 60 is provided on the outer wall surface of the housing 10, and seals the flame extinguishing opening 50 by covering the flame extinguishing opening 50, whereby the accommodation space 104 becomes a sealed space. By making the accommodation space 104 be a sealed space, the entrance of siloxane gas or combustible gas from outside the housing 10 into the accommodation space 104 can be prevented. However, on the inner wall surface of the housing 10, the flame extinguishing hole 50 is maintained as a recess. Therefore, even if combustible gas is contained in the accommodation space 104 and the combustible gas is ignited by arc, the heat is absorbed by the housing 10 when the flame enters the flame extinguishing hole 50 which remains as a recess, whereby the flame is extinguished because it cannot be maintained.Specifically, in this embodiment, the sealing member 60 includes a gas barrier layer 61 that prevents gas existing outside the housing 10 from entering the accommodation space 104. As the gas barrier layer 61, for example, an EVAL film or a nylon film may be used. "EVAL" is a registered trademark.Around the flame extinguishing hole 50 of the housing 10, a recessed portion 105 is formed which is more recessed from the outer wall surface of the housing 10 than the surrounding outer part of the outer wall surface. The gas barrier layer 61 is fixed in this recessed portion 105 using, for example, an adhesive. The depth of the recessed portion 105 and the thickness of the gas barrier layer 61 are arbitrary. However, if the depth of the recessed portion 105 is equal to or greater than the thickness of the gas barrier layer 61, the gas barrier layer 61 can be positioned on the case 10 without protruding outward.In this manner, the structure includes the sealing member 60 defining the flame extinguishing opening 50, while the sealing member 60 seals the flame extinguishing opening 50. Therefore, external siloxane gas or flammable gas outside the housing 10 can be prevented from entering the accommodation space 104 through the flame extinguishing opening 50. Even if flammable gas is present in the accommodation space 104 and ignites to generate a flame, the structure can quench the flame.However, since the gas barrier layer 61 seals the accommodation space 104, it is not possible to discharge the water vapor generated in the accommodation space 104 through the flame extinguishing opening 50. Therefore, a moisture absorbing member 70 is provided in the accommodation space 104.The moisture absorbing member 70 only needs to be inserted into the accommodation space 104. In this embodiment, the moisture absorbing member 70 is formed by applying moisture absorbing materials 71 and 72 to the inner wall surfaces of the housing 10 and the base 12. Specifically, a moisture absorbing material 71 is applied to the entire surface of the case bottom 102 and the four side walls 101 exposed to the accommodation space 104, i.e., the inner portion behind which the base 12 is disposed. In addition, on the entire surface of the base floor 121 exposed to the accommodation space 104, a moisture absorbing material 72 is applied. Here, the moisture absorbing material 72 is not applied to the base body 122 of the base 12, but the moisture absorbing material 72 may be applied to the base body 122 of the base 12.The moisture absorbing materials 71 and 72 are made of, for example, a material in which a desiccant is mixed with resin. As the moisture absorbing material 71 and 72, for example, Dry Keep manufactured by Sasaki Chemical Co., Ltd. can be used. Since the moisture absorbent member 70 is formed by applying the moisture absorbent materials 71 and 72, it is not necessary to provide the space required for a single moisture absorbent member 70. For example, it is sufficient to apply the moisture absorbing materials 71 and 72 to the surface of the existing case 10 or the base 12 exposed to the accommodation space 104.Since the moisture absorbing member 70 is provided inside the accommodation space 104, sealing the flame extinguishing hole 50 with the gas blocking layer 61 can suppress the entrance of siloxane gas and combustible gas. Even if a flame from the flammable gas occurs, it can be extinguished. If water vapor is generated in the accommodation space 104, it may be absorbed by the moisture absorbent 70. This prevents the water vapor from freezing even in environments with minus degrees at the contact surfaces. Therefore, the occurrence of poor contact conductivity due to the influence of siloxane gas or the influence of water vapor inside the accommodation space 104 can be suppressed.Next, the operation of the electromagnetic relay according to this embodiment will be explained. First, when current is applied to the coil 18, the electromagnetic force overcomes the return spring 30, thereby attracting the movable core 28 toward the fixed core 26. As a result, the moving device 36 is pressed by the contact pressure spring 38 and moves by following the movable core 28. As a result, the two movable contacts 40 come into contact with the two fixed contacts 16 and establish the conductivity between the two stators 14.On the other hand, when the energization of the coil 18 is stopped, the return spring 30 presses the movable core 28 and the moving device 36 against the contact pressure spring 38 and urges them away from the fixed core 26. As a result, the two movable contacts 40 are separated from the two fixed contacts 16, thereby interrupting the conduction between the two stators 14.In an environment in which siloxane gas or flammable gas is present in the vicinity of the electromagnetic relay, if the sealing member 60 is not provided, the siloxane gas or flammable gas may enter the accommodation space 104 through the flame extinguishing opening 50. If siloxane gas enters the accommodation space 104, it may cause poor contact. In addition, if combustible gas flows into the accommodation space 104, it may be ignited by the arc generated between the fixed contacts 16 and the movable contacts 40.However, by covering the flame extinguishing hole 50 with the sealing member 60, the entrance of siloxane gas or combustible gas into the accommodation space 104 through the flame extinguishing hole 50 can be prevented. This not only reduces poor contact due to the effects of siloxane gas, but also reduces the risk of ignition of flammable gas. In addition, even if the combustible gas present in the accommodation space 104 is ignited by the arc, the heat of the flames is absorbed by the housing 10 as they enter the flame extinguishing opening 50. As a result, the flames cannot be maintained and extinguished. Therefore, the flame propagation from the flammable gas ignited by the arc to the outside of the electromagnetic relay can be prevented, thereby preventing the ignition of a flammable gas present around the electromagnetic relay.Since the accommodation space 104 is sealed by the sealing member 60 as a closed space, the water vapor, if generated in the accommodation space 104, cannot escape to the outside of the accommodation space 104. However, since the accommodation space 104 is provided with the moisture absorbent 70, the moisture absorbent 70 can absorb the water vapor. The absorption of the water vapor therefore prevents the water vapor from freezing on the contact surfaces even in environments with temperatures below freezing point and thus prevents poor contact conductivity.Second EmbodimentA second embodiment will be described with reference to FIGS. 6 and 7. In the present embodiment, explanations on parts similar or equivalent to those of the first embodiment are omitted or simplified.As shown in FIGS. 6 and 7, in this embodiment, the location of the moisture absorbing member 70 is changed as compared with the first embodiment.[0In the first embodiment, the moisture absorbing material 71 is applied to the entire surface of the case bottom 102 and the four side walls 101 exposed to the accommodation space 104 that is the inner portion behind which the base 12 is positioned. In addition, the moisture absorbing material 72 is applied to the entire surface of the base floor 121 exposed to the accommodation space 104. Therefore, the area around the contact portion consisting of the movable contacts 40 and the fixed contacts 16 is also surrounded by the moisture absorbing member 70.In contrast, in the present embodiment, as shown in FIGS. 6 and 7, the moisture absorbing member 70 is not disposed around the contact portion. Instead, the moisture absorbing member 70 is disposed on the inner wall surfaces of the housing 10 and the base 12 in the vicinity of the coil 18 that faces the contact portion with respect to the central axis of the electromagnetic relay. Specifically, the moisture absorbing member 70 is disposed on the wall surfaces of the housing bottom 102, the side walls 101, and the base bottom 121 defining the accommodation space 104. The moisture absorbing member 70 is disposed in the vicinity of the coil 18 relative to the plate 22, thus surrounding the coil 18, the yoke 24, and the fixed core 26.Thus, in the accommodation space 104, a region where the moisture absorbent member 70 is disposed and a region where the moisture absorbent member 70 is not disposed can be provided. When water vapor is generated inside the accommodation space 104, it is possible to generate a high hydrogen concentration region and a low hydrogen concentration region as shown in FIGS. 6 and 7. Thereby, a water vapor concentration gradient is formed in the accommodation space 104, which allows the water vapor to diffuse from the higher concentration region to the lower concentration region. Therefore, the retention of water vapor in the vicinity of the contact portion can be prevented. In this way, even in environments with temperatures below freezing, water vapor can be prevented from freezing at the contact surfaces, thereby preventing poor contact conduction. [By limiting the locations of the moisture absorbent member 70, it is also possible to reduce the amount of the moisture absorbent member 70 used.Third EmbodimentA third embodiment will be described with reference to FIG. 8. In the present embodiment, explanations on parts similar or equivalent to those of the first embodiment are omitted or simplified.As shown in FIG. 8, in the present embodiment, the structures of the flame extinguishing hole 50 and the sealing member 60 have been changed as compared with the first embodiment.For example, the flame extinguishing hole 50 is a cylindrical or polygonal hole, and the sealing member 60 has a screw structure such that the flame extinguishing hole 50 is disposed inside the screw structure of the sealing member 60.The radial dimension and the depth of the hole of the flame extinguishing hole 50 are set to be capable of extinguishing the flame that has entered the flame extinguishing hole 50. In addition, the sealing member 60 has a cylindrical bottom shape having a hollow cylindrical portion, such as a circular cylindrical bottom shape or a polygonal bottom shape. Moreover, in the portion of the housing 10 surrounding the flame extinguishing opening 50, a recess 105 and a support wall 106 are provided, and an external thread 107 is formed on the outer peripheral wall of the support wall 106. An internal thread 62 corresponding to the external thread 107 is formed on the inner wall surface of the sealing member 60 constituting the hollow portion.The sealing member 60 only needs to be capable of suppressing the penetration of siloxane gas or combustible gas. In other words, the entire sealing member 60 may be made of the same material that can suppress the penetration of siloxane gas or flammable gas, or may have a structure in which the surface is covered with a gas barrier layer to suppress the penetration of siloxane gas or flammable gas. When the sealing member 60 is made entirely of the same material, the sealing member 60 may be made of resin such as PBT (polybutylene terephthalate), ceramic, metal such as iron, or other materials. When the sealing member 60 has a structure in which the surface is covered with a gas barrier layer, the sealing member 60 may be made of, for example, a resin as a base material on the surface of which the gas barrier layer is deposited. In this structure, it is preferable that the entire surface of the sealing member 60 exposed to the outside of the housing 10 is covered. However, it is sufficient if at least the outer wall surface of the bottom of the sealing member 60 is covered with a gas barrier layer.According to such a configuration, by fixing the seal member 60 to the support wall 108 using the internal thread 62 and the external thread 107, the flame extinguishing opening 50 can be sealed by the seal member 60. With such a structure, the sealing member 60 can not only be more securely fixed to the housing 10, but also enables easier fixing of the sealing member 60 to the housing 10.Other EmbodimentsAlthough the present disclosure has been described with reference to embodiments thereof, the disclosure is not limited to these embodiments and constructions. On the contrary, the present disclosure is intended to cover various modifications and equivalent arrangements. Moreover, while the various elements are shown in various combinations and configurations that are exemplary, other combinations and configurations, including more, less, or only a single element, are also within the spirit and scope of the present disclosure.In the above embodiments, the case 10 is made of, for example, resin, but the case 10 may be made of metal. Moreover, in the above embodiments, the base 12 is exemplified as being made of resin, but the base 12 may be made of ceramic.As for the shape of the flame extinguishing hole 50, it is slit-shaped in the first embodiment and cylindrical or polygonal in the third embodiment, but the flame extinguishing hole 50 is not limited to these shapes. As for the location of the flame extinguishing hole 50, in the above embodiments, an example is given in which the flame extinguishing hole 50 is formed in one of the side walls 101 of the housing 10. However, it can also be formed at other locations, such as in the housing bottom 102 or in the bottom of the base 121. In addition, the number of flame extinguishing holes 50 is not limited to one, but may be two or more.The above-described embodiments are not independent of each other and can be combined with each other as appropriate unless the combination is obviously impossible.In the above embodiments, the elements constituting the individual embodiments are not necessarily essential unless expressly stated to be essential or clearly regarded as essential in principle.In addition, in the above embodiments, when the number, value, amount, range, etc. of the elements of the embodiment are mentioned, they are not limited to these specific numbers unless expressly stated to be essential or fundamentally clearly limited to specific numbers.In addition, in the above embodiments, when the shape, positional relationship, etc. of the elements are referred to, they are not limited to these specific shapes or positional relationships unless expressly stated to be essential or clearly limited to specific shapes or positional relationships in principle.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedJP 2023-030225

[0001] JP 2017-084613 A

[0004] JP 2009-059523 A

[0004]

Claims

An electromagnetic relay comprising: a housing (10) having an accommodation space (104) open to the outside through an opening (103); a base (12) fitted into the housing and closing the opening; a coil (18) disposed in the accommodation space and configured to generate an electromagnetic force upon energization; a pair of fixed contactors (14, 16) each having one end disposed in the accommodation space and fixed to the base; a movable contact device (36, 40) disposed in the accommodation space and configured to be driven by the electromagnetic force generated by the coil to make or break contact with the pair of fixed contact devices, wherein the housing or the base has a flame extinguishing opening (50) configured to extinguish a flame, the accommodation space being connected to the outside through the flame extinguishing opening; a sealing member (60) covering the flame extinguishing opening to make the accommodation space a sealed space and prevent gas from entering the inside of the accommodation space from the outside; and a moisture absorbing member (70) disposed in the accommodation space to absorb water vapor in the accommodation space.The electromagnetic relay according to claim 1, wherein the sealing member is a gas barrier layer that is attached to the housing or the base having the flame extinguishing opening and covers the flame extinguishing opening.The electromagnetic relay according to claim 1, wherein the sealing member has a bottomed cylindrical shape having a hollow portion and has an internal thread (62) formed on an inner wall surface defining the hollow portion, the housing or the base having the flame extinguishing opening has a support wall (106) around the flame extinguishing opening, the support wall has an external thread (107) corresponding to the internal thread, the sealing member is fixed to the support wall via the external thread and the internal thread, and the flame extinguishing opening is covered by the sealing member.The electromagnetic relay according to any one of claims 1 to 3, wherein the moisture absorbing member is a moisture absorbing material (71, 72) applied to wall surfaces (101, 102, 121) of the housing and the base defining the accommodation space.The electromagnetic relay according to any one of claims 1 to 3, wherein the moisture absorbing member is a moisture absorbing material (71, 72) applied to the inner wall surfaces (101, 102, 121) of the housing and the base defining the accommodation space, and the moisture absorbing material is not provided in a portion of the inner wall surfaces surrounding a contact portion including a fixed contact (16) of the fixed contact means and a movable contact (40) of the movable contact means, and the moisture absorbing material is provided in a portion of the inner wall surfaces surrounding the coil and different from the portion surrounding the contact portion.

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