Electromagnetic relay

Abstract

The present invention is provided with: a housing (10) that forms an accommodation space (104); the base (12) and the shell form an accommodating space together; a coil (18) that is disposed in the accommodation space and generates an electromagnetic force when energized; a pair of fixed contacts, one end side of which is disposed in the accommodation space and fixed to the base, and the other end side of which protrudes to the outside of the accommodation space, the fixed contacts having fixed contact points (16); and a movable contact disposed in the housing space, the movable contact having a movable contact point (40) that is driven by the electromagnetic force generated by the coil and is brought into contact with and separated from the fixed contact point. In addition, at least one of the fixed contact and the movable contact is provided with an adsorption material (50) at a position different from a position where the fixed contact point and the movable contact point are in contact in the accommodating space.

Description

[0001] Cross Reference to Related Applications

[0002] This application is based on Japanese Patent Application No. 2023-045528 filed on March 22, 2023, the contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present disclosure relates to an electromagnetic relay of a switching circuit. BACKGROUND

[0004] In the past, in an electromagnetic relay, in order to suppress conduction failure caused by water adhering to contacts, a wall surface of a contact cover that constitutes a contact chamber in which a contact portion is housed is provided with a moisture absorbing material, and by adsorbing moisture in the contact chamber, water adhering to the contacts is suppressed (see Patent Literature 1).

[0005] Prior Art Documents

[0006] Patent Literature

[0007] Patent Literature 1: Japanese Patent Application Publication No. 2015-115295 SUMMARY

[0008] In the case where the electromagnetic relay is of an open type, it is structured so that the inside and outside of a housing chamber that houses electrical components constituting the electromagnetic relay are connected, and external air can intrude into the housing chamber. In the case of such an open type electromagnetic relay, if it is used in a cold region or the like, sometimes water vapor is generated from the coil, and the contacts dew. At this time, the following problem occurs: the electromagnetic relay left in an off state, i.e., a state in which the contacts are open, can cause the moisture on the contacts to freeze, causing conduction failure of the contacts.

[0009] On the contrary, if the housing of the electromagnetic relay is structured so as to be airtight, the coil and the contact chamber are completely partitioned, and are structured to be airtight, the above problem can be solved. Further, as shown in Patent Literature 1, by providing an adsorbing material that adsorbs moisture to the housing, water adhering to the contacts can be suppressed.

[0010] However, in the structure in which the coil and the contact chamber are completely partitioned as an airtight type, the following problems occur: the number of components for making the airtight structure increases, and the component processing process such as welding increases due to making the airtight structure. Further, if the adsorbing material is disposed only on the wall surface constituting the contact chamber, the effect of suppressing water adhering to the contacts is not sufficient, and once the adsorbing material adsorbs moisture, it can not be able to adsorb further.

[0011] Note that, here, as the contact failure due to the attachment of water to the contact, an open-type electromagnetic relay is exemplified, but even in a sealed-type electromagnetic relay, the same problem occurs when water vapor is contained in the contact chamber.

[0012] An object of the present disclosure is to provide an electromagnetic relay capable of suppressing contact failure due to dew condensation.

[0013] The electromagnetic relay according to the first aspect of the present disclosure includes: a housing that forms an accommodation space; a base that forms the accommodation space together with the housing; a coil that is disposed in the accommodation space and generates an electromagnetic force when energized; a pair of fixed contacts that are disposed in the accommodation space on an end side and fixed to the base, and protrude to the outside of the accommodation space on the other end side, the fixed contacts having fixed contacts; and a movable contact that is disposed in the accommodation space, has a movable contact that is driven by the electromagnetic force generated by the coil and contacts and separates from the fixed contacts. Further, an adsorbing material is disposed at a position different from a position at which the fixed contact and the movable contact contact the fixed contact and the movable contact in at least one of the fixed contact and the movable contact.

[0014] Thus, even in a state where water vapor is generated from the coil due to energization and water vapor exists in the accommodation space, since the adsorbing material is disposed in the vicinity of the fixed contact, the moisture of the contact portion can be adsorbed. Therefore, dew condensation of the fixed contact or the movable contact can be suppressed. Further, since the temperature of the fixed contact or the movable contact can be increased by the adsorption heat generated due to the adsorption of moisture, dew condensation of the contact can be suppressed, and even if water is attached to the fixed contact, the freezing of the water can be suppressed.

[0015] Further, since the fixed contact or the movable contact that becomes a current path is provided with the adsorbing material, by the heat generation at the time of energization, the water adsorbed on the adsorbing material can be desorbed. Therefore, even if the adsorbing material temporarily adsorbs moisture, since the moisture can be desorbed at the time of energization, the adsorption effect of the adsorbing material is restored. Therefore, the adsorption effect of the adsorbing material can be maintained at a high level, and the moisture can be repeatedly adsorbed.

[0016] Therefore, the contact failure due to the influence of water vapor existing in the accommodation space can be further suppressed.

[0017] In the second aspect of the present disclosure, in a case where the pair of fixed contacts are respectively provided with a structure having a fixed contact at one end and a fixed member that serves as an external connection terminal at the other end, the adsorbing material is disposed at a position where the fixed member becomes a current path.

[0018] In this way, if the adsorbent is also arranged in the portion constituting the current path in the fixing member, the temperature can be further increased, and the desorption of water from the adsorbent can be accelerated.

[0019] As described in the third aspect of the present disclosure, preferably, on one of the pair of fixed contacts, an adsorbent material is provided extending toward the other end while in contact with the fixed contact. Thus, by extending the adsorbent material over the portion of the fixed member that forms the current path and contacting the fixed contact, moisture near the fixed contact can be further adsorbed. Furthermore, by transferring adsorption heat to the fixed contact, the contact temperature is increased, thereby suppressing condensation on the contact.

[0020] Furthermore, as described in the fourth aspect of the present disclosure, preferably, in a configuration where two fixed contacts are arranged side by side on the other side of a pair of fixed contacts, and two movable contacts are also arranged side by side on the side of the movable contact that contacts the two fixed contacts arranged side by side, the adsorbent material is arranged between the two fixed contacts, contacting the two fixed contacts. In this manner, by extending the adsorbent material over the portion of the fixed member that constitutes the current path and contacting the fixed contacts, moisture near the fixed contacts can be further adsorbed. Furthermore, by transferring adsorption heat to the fixed contacts, the contact temperature is increased, thereby suppressing condensation on the contacts.

[0021] Note that the parenthesized reference numerals attached to the respective components and the like are provided to show an example of a correspondence relationship between the components and the like and specific components and the like described in the embodiments to be described later. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a diagram showing a cross-sectional structure of an electromagnetic relay according to the first embodiment of the present disclosure.

[0023] Figure 2 yes Figure 1 Sectional view II-II in .

[0024] Figure 3 It is from Figure 1 The diagram showing a portion extracted from the electromagnetic relay is a perspective view of the base and the components assembled on the base, shown from a perspective allowing the movable contact to be visually recognized.

[0025] Figure 4 yes Figure 3 Magnified view of region R in FIG.

[0026] Figure 5 It shows Figure 2 The cross-sectional view of the electromagnetic relay shown is in the turned-on state. DETAILED DESCRIPTION

[0027] Hereinafter, embodiments of the present disclosure will be described based on the accompanying drawings. It should be noted that, in the following embodiments, identical or equivalent parts are denoted by the same reference numerals.

[0028] The following describes the embodiments of the present disclosure with reference to the accompanying drawings. It should be noted that, in the following embodiments, portions that are identical or equivalent to those described in the preceding embodiments may be denoted by the same reference numerals, and their descriptions may be omitted. Furthermore, in each embodiment, when only a portion of the components is described, the components described in the preceding embodiments may be applied to the remaining components.

[0029] (First embodiment)

[0030] The electromagnetic relay according to the present embodiment is used to turn on and off the power supply to electrical equipment used in vehicles and the like, and is used in, for example, electric vehicles equipped with fuel cells.

[0031] like Figure 1 、 Figure 2 As shown, the electromagnetic relay according to this embodiment includes a resin housing 10. Housing 10 has four sidewalls 101 and a housing bottom 102, forming a bottomed rectangular tube. A housing space 104 is formed within housing 10. This housing space 104 is open to the outside via a breathing hole 105 formed in base 12 near coil terminal 20.

[0032] The resin base 12 is fitted into the housing 10 and includes a base bottom portion 121, a base body portion 122 that protrudes from the base bottom portion 121 toward the housing bottom 102, and a base spring receiving portion 123 that holds a pressure contact spring 38, described later. Furthermore, the housing 10 and the base bottom portion 121 define a housing space 104. The base 12 is insert-molded with a pair of fixing members 14, described later, as inserts.

[0033] Two terminal insertion holes (not shown) are formed in the base bottom portion 121 , into which a pair of coil terminals 20 described later are inserted.

[0034] When the base 12 is assembled to the housing 10, as shown by arrow X, the base 12 is moved relative to the housing 10. Figure 1 The base 12 is relatively moved from the right side of the paper toward the left side to insert the base 12 into the housing 10. Hereinafter, the insertion direction of the base 12 when assembling the base 12 into the housing 10 is referred to as the base insertion direction X. It should be noted that the housing 10 and the base 12 are bonded together by applying an adhesive at the fitting portion.

[0035] like Figure 2 、 Figure 3As shown, a pair of fixed members 14 made of a plate of an electrically conductive metal is fixed to the base 12. As shown Figure 2 and Figure 3 As shown, one end side of the fixed member 14 is fixed to the base body portion 122, inside the housing space 104, and as shown Figure 1 the other end side protrudes to the outside, constituting an external connection terminal. A fixed contact 16 made of an electrically conductive metal is riveted and fixed to the end portion of the fixed member 14 on the side of the housing space 104. The end portion of the fixed member 14 on the side of the external space becomes an external connection terminal that connects to an external circuit not shown. Note that the fixed member 14 and the fixed contact 16 constitute a fixed contact.

[0036] As for the fixed contact 16, one is formed for each fixed member 14, but in the case of the present embodiment, only one fixed contact 16a is provided for one fixed member 14a, and two fixed contacts 16b are provided for the other fixed member 14b. As shown Figure 3 the fixed member 14a is set wide in the portion constituting the external connection terminal, and is set narrower than the portion constituting the external connection terminal on the side of the housing space 104, and the fixed contact 16a is arranged on the portion of the fixed member 14a that is set narrow. The fixed member 14b is also set wide in the portion constituting the external connection terminal, and is set narrower than the portion constituting the external connection terminal on the side of the housing space 104, and two fixed contacts 16b are arranged side by side at a prescribed distance apart in the length direction of the fixed member 14b on the portion of the fixed member 14a that is set narrow.

[0037] Therefore, the fixed member 14a makes one-point contact with the movable contact described later through the one fixed contact 16a. Also, the fixed member 14b is set so as to be able to make two-point contact with the movable contact described later through the two fixed contacts 16b.

[0038] A cylindrical coil 18 that generates an electromagnetic force when energized is arranged in the housing space 104, and a pair of coil terminals 20 made of an electrically conductive metal is connected to the coil 18.

[0039] The coil terminals 20 are inserted into a terminal insertion hole not shown formed in the base bottom portion 121, and the end portions protrude to the outside of the electromagnetic relay, constituting external connection terminals. Also, the coil terminals 20 are connected to an ECU not shown via an external wire harness, and the coil 18 is energized via the external wire harness and the coil terminals 20.

[0040] A disc-shaped plate 22 made of a ferromagnetic metal material is arranged on the base body portion 122 side of the coil 18. A yoke 24 made of a ferromagnetic metal material is arranged on the side opposite the base body portion and the outer periphery side of the coil 18. Note that the plate 22 and the yoke 24 are fixed to the base 12.

[0041] A cylindrical stationary core 26 made of a ferromagnetic metal material is arranged in the inner peripheral side space of the coil 18, and is held on the yoke 24.

[0042] A disc-shaped movable core 28 made of a ferromagnetic metal material is arranged between the base body portion 122 and the plate 22. Further, a return spring 30 that exerts a force on the movable core 28 to the side opposite to the stationary core is arranged between the coil 18 and the movable core 28.

[0043] Further, when the coil 18 is energized, the movable core 28 is attracted to the stationary core 26 side against the return spring 30 by the electromagnetic force generated by the coil 18. Note that the plate 22, the yoke 24, the stationary core 26, and the movable core 28 constitute a magnetic path of the magnetic flux induced by the coil 18.

[0044] A metal shaft 32 is fixedly inserted through the movable core 28. One end of the shaft 32 extends toward the side opposite to the stationary core, and a bushing 34 made of a resin having good electrical insulation is fitted and fixed to the end portion of the one end side of the shaft 32. The other end side of the shaft 32 is slidably inserted into the stationary core 26.

[0045] A movable member 36 made of a conductive metal plate is arranged in the accommodation space 104. A press contact spring 38 that exerts a force on the movable member 36 to the bushing 34 side is arranged between the movable member 36 and the base spring receiving portion 123. A pair of movable contacts 40 made of a conductive metal are rivet-fixed to the movable member 36 at positions opposite to the pair of stationary contacts 16. Note that the movable member 36 and the movable contacts 40 constitute a movable contact.

[0046] The movable contacts 40 are formed one by one in correspondence with the number of the stationary members 14, but in the present embodiment, the number is set to be the same as that of the stationary contacts 16a and 16b. That is, only one movable contact 40a is provided at one end of the movable member 36 at a position corresponding to the stationary contact 16a, and although only one is shown in Figure 2 , two movable contacts 40b are provided at the other end of the movable member 36 at a position corresponding to the stationary contact 16b. The movable member 36 is made of a plate as described above, but at the side where the movable contacts 40b are arranged, the other end of the movable member 36 is bifurcated in a T shape, and one movable contact 40b is arranged at the front end of each of the bifurcations. That is, the left-right direction in Figure 2 , in other words, the direction in which the movable contacts 40a and 40b are arranged, is taken as the length direction of the movable member 36, and the two movable contacts 40b are arranged side by side at a predetermined distance in a direction intersecting, for example, orthogonal to the length direction of the movable member 36.

[0047] Therefore, the movable contact 40a makes one-point contact with one fixed contact 16a. Further, two movable contacts 40b are arranged to make two-point contact with two fixed contacts 16b.

[0048] A pair of permanent magnets 42 is arranged in the recess of the base body portion 122, and generates a magnetic field at the contact separation portions where the fixed contacts 16 and the movable contacts 40 make contact and separation, thereby elongating the electric arc generated between the fixed contacts 16 and the movable contacts 40. These permanent magnets 42 are arranged opposite to each other in the arrangement direction of the pair of contact separation portions (the lateral direction of the paper). Figure 2

[0049] Note that the structure in which the sealed accommodation space 104 is sealed only by the case 10 and the base 12 can also be provided. However, the case 10 and the base 12 need to be made of metal or ceramic to be welded or the like, and the degree of freedom of material selection and manufacturing process is reduced. Therefore, in the present embodiment, the electromagnetic relay is provided as an open type, and is not provided as a closed type in which the case 10 and the base 12 are sealed and the coil 18 and the contact portion are completely separated. Of course, the problem of conduction failure due to water adhering to the contact portion is particularly concerning in the open type, but even in the electromagnetic relay of the closed type, the same problem occurs when water vapor is contained in the contact chamber. Therefore, the electromagnetic relay can also be provided as a closed type.

[0050] Further, in the present embodiment, as shown in Figs. 1 and 2, the fixed contacts 16 of the fixed members 14 are arranged in the vicinity of the movable contacts 40 of the movable member 20. Figure 3 Figure 4 Specifically, in the case of the fixed member 14a, the adsorbing material 50a is arranged to extend from the fixed contact 16a toward the other end side of the fixed member 14a constituting the external connection terminal while making contact with the fixed contact 16a. Further, in the case of the fixed member 14b, the adsorbing material 50b is arranged to extend between the two fixed contacts 16b of the fixed member 14b while making contact with the two fixed contacts 16b.

[0051] The adsorbing material 50 can be arranged in the vicinity of the fixed contact 16 of the fixed member 14 made of metal, but in the present embodiment, the adsorbing material 50 is arranged at the position of the current path in the fixed member 14. Further, as a more preferable mode, the adsorbing material 50 is arranged to make contact with the fixed contact 16.

[0052] ​​The adsorbing material 50 is a material having an adsorbing effect, and can be any material as long as it is a material that can release adsorbed moisture using heat, such as a material in which a desiccant is mixed in activated carbon or a resin. In the present embodiment, activated carbon is used as the adsorbing material 50, and, for example, the activated carbon is applied in a liquid or paste state and then cured to be disposed on the fixed member 14. Since the adsorbing material 50 is formed by application, it can also not require a space that is required when the adsorbing material 50 is provided as a separate component.

[0053] As described above, the electromagnetic relay according to the present embodiment is constructed. Next, the operation of the electromagnetic relay according to the present embodiment will be described.

[0054] First, when the coil 18 is energized, the movable iron core 28 is attracted to the fixed iron core 26 side against the return spring 30 by the electromagnetic force thereof, and the movable member 36 is moved following the movable iron core 28 by the urging force of the press contact spring 38. Thus, as shown in FIG. 2, the two movable contacts 40 are brought into contact with the two fixed contacts 16, and conduction is established between the pair of fixed members 14. Figure 5

[0055] On the other hand, when energization to the coil 18 is cut off, the movable iron core 28 and the movable member 36 are urged to the side opposite to the fixed iron core 26 by the return spring 30 against the press contact spring 38. Thus, as shown in FIG. 3, the two movable contacts 40 are separated from the two fixed contacts 16, and conduction between the pair of fixed members 14 is cut off. Figure 2

[0056] Here, in the case where the electromagnetic relay is provided as an open type like the present embodiment, water vapor is generated from the coil 18 due to energization, and the fixed contacts 16 and the movable contacts 40 can be dewed in a state where the water vapor exists in the housing space 104. However, in the electromagnetic relay of the present embodiment, since the adsorbing material 50 is disposed in the vicinity of the fixed contacts 16, moisture can be adsorbed. In particular, by disposing the adsorbing material 50 in contact with the fixed contacts 16, moisture in the vicinity of the fixed contacts 16 can be further adsorbed.

[0057] Thus, dewing of the fixed contacts 16 and the movable contacts 40 can be suppressed. Furthermore, since the temperature of the fixed contacts 16 can be increased by adsorption heat generated by adsorption of moisture, dewing of the fixed contacts 16 can be suppressed, and even if water adheres to the fixed contacts 16, freezing of the water can be suppressed.

[0058] ​​Further, since the fixing member 14 that becomes the current path is provided with the adsorbing material 50, water adsorbed on the adsorbing material 50 can be desorbed by heat generated at the time of energization. In particular, if the portion of the fixing member 14 that constitutes the current path is also provided with the adsorbing material 50, the temperature becomes higher, and desorption of water from the adsorbing material 50 can be promoted. Therefore, even if the adsorbing material 50 temporarily adsorbs moisture, since the moisture can be desorbed at the time of energization, the adsorbing effect of the adsorbing material 50 is restored. Therefore, the adsorbing effect of the adsorbing material 50 can be maintained at a high level, and moisture can be repeatedly adsorbed.

[0059] Therefore, contact conduction failure due to the influence of water vapor present in the accommodation space 104 can be suppressed.

[0060] (Other Embodiments)

[0061] The present disclosure is not limited to the above-described embodiments, and can be changed as appropriate within the scope recited in the claims.

[0062] For example, in the above-described embodiments, the adsorbing material 50 is provided to the fixing member 14, but the adsorbing material 50 can also be provided to the movable member 36. As long as the adsorbing material 50 is provided to at least one of the fixing member 14 and the movable member 36, it can also be provided to both. In the case of being provided to the movable member 36, the adsorbing material 50 can be provided between one movable contact 40a and the other movable contact 40b or between two movable contacts 40b. In this case, if the adsorbing material 50 is provided in a manner that contacts the movable contact 40a between the movable contact 40a and the movable contact 40b or contacts both movable contacts 40b between the two movable contacts 40b, since water adhering to each movable contact 40a, 40b can be better adsorbed, this is preferable.

[0063] Further, in each of the above-described embodiments, the case in which the housing 10 is made of resin is exemplified, but the housing 10 can also be made of metal. Further, in each of the above-described embodiments, the case in which the base 12 is made of resin is exemplified, but the base 12 can also be made of ceramic. Depending on the material of the housing 10 and the base 12, the electromagnetic relay can also be provided as airtight, but even if it is provided as airtight, by providing the adsorbing material 50 to the metal that constitutes the current path in the case in which water vapor is present in the accommodation space 104, the above-described effects can be obtained.

[0064] Of course, the structure of the electromagnetic relay and the like are merely an example, and other structures can be provided. Even in this case, by providing the adsorbing material 50 at a position different from the position at which the fixed contact 16 and the movable contact 40 in the housing space 104 are in contact, in at least one of the metal portions that constitute the current path in the electromagnetic relay, i.e., the fixed contact and the movable contact, the above-described effects can be obtained.

[0065] Note that in each of the above-described embodiments, elements constituting the embodiments are not necessarily essential except in cases where it is explicitly stated that they are essential, and in cases where they are obviously essential in principle, and the like.

[0066] Further, in each of the above-described embodiments, in cases where a number of elements constituting the embodiments, numerical values, amounts, ranges, and the like are mentioned, they are not limited to a specific number except in cases where it is explicitly stated that they are essential, and in cases where they are obviously limited to a specific number in principle, and the like.

[0067] Further, in each of the above-described embodiments, in cases where a shape, positional relationship, and the like of an element constituting the embodiments are mentioned, they are not limited to a specific shape, positional relationship, and the like except in cases where it is explicitly stated that they are essential, and in cases where they are obviously limited to a specific shape, positional relationship, and the like in principle, and the like.

Claims

1. An electromagnetic relay comprising: a housing (10) that forms an accommodation space (104); a base (12) that forms the accommodation space together with the housing; a coil (18) that is disposed in the accommodation space and generates an electromagnetic force when energized; a pair of fixed contacts (14, 16) that are disposed in the accommodation space on one end side thereof and fixed to the base on the other end side thereof, the fixed contacts having fixed contact points (16); and a movable contact (36, 40) that is disposed in the accommodation space and has movable contact points (40) that are driven by the electromagnetic force generated by the coil and come into contact with and separate from the fixed contact points, wherein an adsorbing material (50) is disposed at a position of at least one of the fixed contacts and the movable contact that is different from a position at which the fixed contact points and the movable contact points in the accommodation space come into contact.

2. The electromagnetic relay according to claim 1, wherein the adsorbing material is provided to the fixed contacts, the pair of fixed contacts each has a fixed piece (14) that has the fixed contact point on the one end side thereof and is used as an external connection terminal on the other end side thereof, and the adsorbing material is disposed at a position of the fixed piece that becomes a current path.

3. The electromagnetic relay according to claim 2, wherein in one of the pair of fixed contacts, the adsorbing material is disposed so as to extend toward the other end side thereof while coming into contact with the fixed contact point (16a).

4. The electromagnetic relay according to claim 2 or 3, wherein in the other of the pair of fixed contacts, two fixed contact points (16b) are disposed side by side, two movable contact points are disposed side by side on a side of the movable contact that comes into contact with the two fixed contact points disposed side by side, and the adsorbing material is disposed so as to come into contact with the two fixed contact points between the two fixed contact points disposed side by side. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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