JP7119680B2 - closed relay - Google Patents

Description

TECHNICAL FIELD The present disclosure relates to a closed relay, and more particularly to a closed relay using silver tungsten or silver tungsten carbide as a contact material.

In a relay that mechanically opens and closes an electric circuit, a fixed contact is provided on the fixed terminal, and a movable contact is provided on the movable terminal. By moving the movable terminal, the fixed contact and the movable contact are in contact/non-contact state. , to open and close electrical circuits. As a material for the fixed contact and the movable contact, a tin oxide-based material such as AgSnO ₂ and AgSnO ₂ In ₂ O ₃ is used as a material that contains an oxide and is resistant to welding. In addition, when fixed contacts and movable contacts are exposed to the atmosphere, failures due to contamination and corrosion of the contacts, especially welding failures, occur. See Patent Document 1).

WO01/004368

However, in relays enclosed in a container, welding failure may occur even though contact contamination and corrosion can be prevented.

Accordingly, an object of the present disclosure is to provide a closed-type relay that has a closed-type structure in which fixed terminals and movable terminals are covered with a container, and that prevents welding failures between contacts.

An example of this disclosure is:
a base to which a movable terminal having a movable contact, a fixed terminal having a fixed contact, and a coil are attached;
a case attached to the base, the case enclosing the movable terminal, the fixed terminal, and the coil in a space defined by the base;
A closed-type relay in which the movable terminal is moved by a magnetic force generated by supplying a current to the coil to bring the movable contact and the fixed contact into contact or non-contact,
at least one of the movable contact and the fixed contact;
A closed relay characterized by containing 40% by weight or more of silver and 1% by weight or more of tungsten and/or tungsten carbide.

In the closed relay according to the present disclosure, it is possible to prevent welding between the movable terminal and the fixed contact during opening/closing operation (relay/switching), thereby extending the life of the closed relay.

1 shows a perspective view of a closed relay according to the present disclosure; FIG. 1 shows a schematic diagram of the internal structure of a closed relay according to the present disclosure; FIG. 1 shows a schematic diagram of the internal structure of a closed relay according to the present disclosure; FIG. 2 shows the relationship between the number of times the contact is opened and closed and the oxygen concentration in the closed space when the contact is made of an AgSnO-based material. Evaluation results for Examples and Comparative Examples are shown.

An example of the present disclosure will now be described with reference to the accompanying drawings. In the following description, terms indicating specific directions or positions (for example, terms including “upper”, “lower”, “right”, and “left”) are used as necessary, but the use of these terms is are intended to facilitate understanding of the present disclosure with reference to the drawings, and the technical scope of the present disclosure is not limited by the meanings of these terms. Also, the following description is merely exemplary in nature and is not intended to limit the present disclosure, its applications, or its uses. Furthermore, the drawings are schematic, and the ratio of each dimension does not necessarily match the actual one.

FIG. 1 is a perspective view of a closed relay (relay) in accordance with the present disclosure, generally designated 100, shown prior to closure. 2A and 2B are schematic diagrams of the internal structure of the closed relay of FIG. 1, showing states before and after switching of the relay.

As shown in FIG. 1, closed relay 100 includes base 10 and case 20 . The base 10 and the case 20 are made of a resin material such as polybutylene terephthalate (PBT) or liquid crystal polymer (LDP). A coil 30 is mounted on the base 10 . A movable terminal 40 and a fixed terminal 50 are provided on the base 10 . The movable terminal 40 is provided with a movable contact 45 , and the fixed terminal 50 is provided with a fixed contact 55 . Both the movable terminal 40 and the fixed terminal 50 are made of a conductive material, and the movable terminal 40 uses a conductive spring material. As shown in FIGS. 2A and 2B, the case 20 is fixed on the base 10 with an adhesive to close the inside.

The closed relay 100 is in a state in which the case 20 is adhered to the base 10 and air (atmosphere) is contained inside. The closed-type relay 100 can completely prevent foreign objects and liquids from entering the relay (for example, pass a bubble leak test of A50 or higher), but allows air to enter and exit, and blocks the entry and exit of air. Unlike sealed relays. However, as will be described later, when an arc discharge occurs inside, oxygen inside is consumed and the oxygen concentration decreases.

In the closed relay 100, the movable contact 45 of the movable terminal 40 and the fixed contact 55 of the fixed terminal 50 are made of silver tungsten (AgW) or silver tungsten carbide (AgWC). Here, silver tungsten (AgW) contains 40% by weight or more of silver and 1% by weight or more of tungsten, preferably 40% by weight or more and 99% by weight or less of silver and 1% by weight or more of tungsten. 60 wt% or less, more preferably 40 wt% or more and 97 wt% or less of silver, 3 wt% or more and 60 wt% or less of tungsten, or 85 wt% or more and 99 wt% or less of silver, and 1 wt% of tungsten % or more and 15 wt % or less, particularly preferably 85 wt % or more and 97 wt % or less of silver, and 3 wt % or more and 15 wt % or less of tungsten.

Also, silver tungsten carbide (AgWC) contains 40 wt% or more silver and 1 wt% or more tungsten carbide, preferably 40 wt% or more and 99 wt% or less of silver and 1 wt% of tungsten carbide. 60 wt% or less, more preferably 40 wt% or more and 97 wt% or less of silver, 3 wt% or more and 60 wt% or less of tungsten carbide, or 85 wt% or more and 99 wt% or less of silver, tungsten 1% to 15% by weight of carbide, particularly preferably 85% to 97% by weight of silver, and 3% to 15% by weight of tungsten carbide.

Silver tungsten (AgW) and tungsten carbide (AgWC) may contain unavoidable impurities. Furthermore, trace additives include carbon (C), iron (Fe), nickel (Ni), cobalt (Co), chromium (Cr), molybdenum (Mo), copper (Cu), tantalum (Ta), vanadium (V ), magnesium (Mg), zinc (Zn), tin (Sn), indium (In), bismuth (Bi), palladium (Pd), lanthanum (La), cerium (Ce), thorium (Th), yttrium (Y ) and zirconium (Zr). By including these elements, a longer-life closed-type relay can be obtained.

Both the movable contact 45 and the fixed contact 55 are preferably made of tungsten (AgW) or tungsten carbide (AgWC). For example, AgSn may be used.

Next, the relay/switching operation of the closed relay 100 will be described with reference to FIGS. 2A and 2B.
FIG. 2A shows a state in which no current is applied to the coil 30, the movable contact 45 of the movable terminal 40 and the fixed contact 55 of the fixed terminal 50 are in contact, and the two terminals are in a conducting state. .

FIG. 2B shows a state in which current is applied to the coil 30, and the iron core 60 is magnetized to attract the movable terminal 40. FIG. As a result, the movable contact 45 of the movable terminal 40 is separated from the fixed contact 55 of the fixed terminal 50, and the conduction state between the two terminals is released.

In the closed relay 100, the relay/switching action is performed by turning on/off the current to the coil 30. FIG. The coil 30 has a magnetomotive force greater than or equal to 1 ampere-turn and less than or equal to 750,000 ampere-turns, preferably greater than or equal to 1 ampere-turn and less than or equal to 300,000 ampere-turns. In the closed relay 100, the external volume is 1 cc or more and 100 cc or less, preferably 1 cc or more and 20 cc or less. Here, the outer volume is the volume of the closed relay 100 excluding the terminals, and is substantially equal to the outer volume of the case 20 .

Here, an example in which the coil 30 is turned on when a current is supplied has been described, but a structure in which the coil 30 is turned off when a current is supplied may be employed. Alternatively, it may have a structure in which two fixed terminals and a movable terminal sandwiched therebetween are provided, and the movable terminals are alternately connected to the two fixed terminals. In this case, at least one of the contacting movable contact 45 and fixed contact 55 may be made of the above material.

Next, the principle by which welding failure can be suppressed in the closed relay 100 according to the present embodiment will be described.
Conventionally, in relays, AgSnO-based materials, for example, have been used as materials for movable contacts and fixed contacts as materials that have high conductivity and can prevent welding. In the AgSnO-based material, highly conductive Ag is the main component, and SnO ₂ , which is an oxide, is added therein, so that both high conductivity and prevention of welding are possible. In other words, even if an arc is generated between the movable contact and the fixed contact and _SnO2 is decomposed, Sn is reoxidized by oxygen in the atmosphere and returns to oxide _SnO2 , thereby preventing welding.

Here, if dust or corrosive gas adheres to the contact surface and the contact surface is contaminated or corroded, the stable operation of the relay/switch is hindered. In the closed relay 100, the inside surrounded by the base 10 and the case 20 is a closed space, so when the Ag is oxidized by the arc discharge that occurs at the moment the contacts come into contact, the oxygen concentration inside gradually decreases. do.

FIG. 3 shows the relationship between the number of times the contacts are opened and closed (relay/switch times) and the oxygen concentration in the closed space when the movable and fixed contacts are made of AgSnO-based materials. As can be seen from FIG. 3, the oxygen concentration in the closed space decreases as the number of times of opening and closing increases. That is, the arc discharge oxidizes Ag in the AgSnO-based material,
4Ag _{+ O2} →2Ag2O
Oxygen in the closed space is consumed by the oxidation reaction of .

On the other hand, the oxide SnO2 in the AgSnO _- based material is decomposed by arc discharge,
SnO2→Sn _{+ O2}
However, since the oxygen concentration is low in the closed container, Sn is not reoxidized, and the amount of oxide SnO ₂ in the AgSnO-based material decreases.

Table 1 lists the melting points of typical materials used in relay terminals.

Table 1

As shown in Table 1, the melting point of SnO ₂ is 1625°C, but when it becomes Sn, the melting point drops to 232°C. Along with this, the softening temperature of Sn is also significantly _lower than that of SnO2.

For this reason, in conventional closed-type relays using AgSnO-based materials for contacts, when the number of switching times increases, the amount of SnO ₂ in the contacts decreases and the amount of Sn increases, the contacts soften and become more susceptible to welding.

In contrast, in the present disclosure, tungsten (AgW) or tungsten carbide (AgWC) is used as the material of the movable contact 45 and the fixed contact 55 . In these materials, even if Ag is oxidized by arc generation and the oxygen concentration in the closed space is reduced, W or WC is not decomposed by the arc, and reoxidation is not required.

Therefore, even if the number of opening/closing times (relay/switching times) of the closed relay 100 increases, the terminal material does not soften and welding failures between the terminals can be prevented.

In a low-oxygen atmosphere such as the inside of the closed relay 100, such a welding failure is particularly problematic in the AC voltage range of 50 to 300 V and the rated current range of 5 A to 30 A. That is, in a low-oxygen atmosphere, the thermal pinch effect increases the arc density and shortens the arc duration time.

For example, when the DC load voltage between terminals is DC 12 to 30 V, although the arc density increases in a low-oxygen atmosphere, the duration of the arc is shortened, so the total amount of damage received by the contact terminals is relatively small. On the other hand, when the AC load voltage between the terminals is 50 V to 300 V, the arc duration time depends only on the zero cross time peculiar to AC. Therefore, in a low-oxygen atmosphere, the arc density increases and the duration does not change, resulting in greater damage to the contact terminals.

Next, closed-type relays (Examples 1 and 2) having terminals formed from a material according to the present disclosure and closed-type relays having terminals formed from other materials (Comparative Examples 1 and 2) were subjected to opening and closing operations. The results of (relay/switching operation) are shown.

Table 2 shows the compositions of the terminals of the relays used in Examples 1 and 2 and Comparative Examples 1 and 2. As shown in the conditions, all relays were closed type relays.

Table 2

Table 3 shows the conditions used for evaluation. The voltage/current applied between the movable terminal and the fixed terminal was AC 250 V/16 A, and the opening and closing of the terminal was repeated for 1.0 seconds ON (contact)/9.0 seconds OFF (non-contact). . The test atmosphere temperature is 23° C. (room temperature).

Table 3

The evaluation was made based on the number of opening/closing operations until welding failure occurred between the terminals under these evaluation conditions. Five samples were evaluated for each of the comparative examples and examples. Figure 4 shows the evaluation results.

As is clear from FIG. 4, in Comparative Example 1 (Ag-SnO ₂ 12 wt%), welding failure occurred after opening and closing 20,000 times or less, and in Comparative Example 2 (Ag-Ni 10 wt%), about 60,000 times. A welding failure occurred. On the other hand, in Example 1 (Ag-W 10 wt%) and Example 2 (Ag-W 60 wt%), opening and closing of 100,000 times or more became possible.

In this way, by using AgW-based material (Ag-W10wt%Ag-W60wt%) as the terminal material, softening of the terminal material occurs in the switching operation (relay/switching operation) of the closed relay as in the comparative example. It was found that it is possible to prevent welding failure and extend the life of the product.

The embodiments according to the present disclosure have been described above with reference to the drawings. Finally, various aspects of the present disclosure will be described. In addition, in the following description, as an example, reference numerals are attached.

The closed relay 100 of the first aspect of the present disclosure includes:
a base 10 to which a movable terminal 40 having a movable contact 45, a fixed terminal 50 having a fixed contact 55, and a coil 30 are attached;
a case 20 attached to the base 10, the case 20 enclosing the movable terminal 40, the fixed terminal 50, and the coil 30 in a space formed by the base 10;
A closed-type relay 100 that moves the movable terminal 40 by a magnetic force generated by supplying a current to the coil 30 to make contact or non-contact between the movable contact 45 and the fixed contact 55,
At least one of the movable contact 45 and the fixed contact 55 is
40% by weight or more of silver and 1% by weight or more of tungsten and/or tungsten carbide.

According to the closed relay 100 of the first aspect of the present disclosure, welding between the movable terminal 40 and the fixed terminal 50 is prevented during opening/closing operation (relay/switching), and the life of the closed relay 100 is extended. becomes possible. In particular, in closed-type relays, welding can be prevented even in an environment where the oxygen concentration is low.

The closed relay 100 of the second aspect of the present invention is
a base 10 to which a movable terminal 40 having a movable contact 45, a pair of fixed terminals 50 having a fixed contact 55 arranged opposite to each other with the movable terminal 40 interposed therebetween, and a coil 30;
a case 20 attached to the base 10, the case 20 enclosing the movable terminal 40, the fixed terminal 50, and the coil 30 in a space formed by the base 10;
A closed type relay 100 in which the movable contact 45 of the movable terminal 40 is brought into contact with the fixed contact 55 of one of the fixed terminals 50 by moving the movable terminal 40 by the magnetic force generated by supplying the current to the coil 30. There is
At least one of the movable contact 45 and the fixed contact 55 is
40% by weight or more of silver and 1% by weight or more of tungsten and/or tungsten carbide.

According to the closed relay 100 of the second aspect of the present disclosure, welding between the two movable terminals 40 and the fixed terminal 50 is prevented during opening/closing operation (relay/switching), and the closed relay 100 Long life is possible. In particular, in closed-type relays, welding can be prevented even in an environment where the oxygen concentration is low.

In the closed relay 100 of the third aspect of the present disclosure,
At least one of the movable contact 45 and the fixed contact 55 is
40% to 99% by weight of silver and 1% to 60% by weight of tungsten and/or tungsten carbide.

According to the closed relay 100 of the third aspect of the present disclosure, it is possible to prevent welding between the movable terminal 40 and the fixed terminal 50 during opening and closing operations, thereby extending the life of the closed relay.

In the closed relay 100 of the fourth aspect of the present disclosure,
At least one of the movable contact 45 and the fixed contact 55 is
85% to 97% by weight of silver and 3% to 15% by weight of tungsten and/or tungsten carbide.

According to the closed relay 100 of the fourth aspect of the present disclosure, it is possible to prevent welding between the movable terminal 40 and the fixed terminal 50 during opening and closing operations, thereby extending the life of the closed relay.

In the closed relay 100 of the fifth aspect of the present disclosure,
At least one of said movable contact 45 and said fixed contact 55 may further comprise carbon, iron, nickel, cobalt, chromium, molybdenum, copper, tantalum, vanadium, magnesium, zinc, tin, indium, bismuth, palladium, lanthanum, cerium. , thorium, yttrium and zirconium as an additive.

According to the closed relay 100 of the fifth aspect of the present disclosure, a closed relay with a longer life is obtained.

In a sixth aspect of the present disclosure,
An alternating current is supplied between the movable terminal 40 and the fixed terminal 50 .

In the closed relay 100 of the sixth aspect of the present disclosure, welding between the movable terminal 40 and the fixed terminal 50 during opening and closing operations is prevented even against an alternating current that greatly damages the contact terminals, It is possible to extend the life of the closed type relay.

In a seventh aspect of the present disclosure,
The alternating current has an alternating voltage of 50 V or more and 300 V or less and a rated current of 5 A or more and 30 A or less.

According to the closed relay 100 of the seventh aspect of the present disclosure, generally in a low-oxygen atmosphere, the arc density increases and the duration does not change. It is possible to prevent the welding of the closed type relay and extend the life of the closed type relay.

In an eighth aspect of the present disclosure,
The coil has a magnetomotive force greater than or equal to 1 ampere-turn and less than or equal to 750,000 ampere-turn.

According to the closed relay 100 of the eighth aspect of the present disclosure, it is possible to extend the life of the closed relay using such a coil.

In a ninth aspect of the present disclosure,
The coil has a magnetomotive force greater than or equal to 1 ampere-turn and less than or equal to 300,000 ampere-turn.

According to the closed relay 100 of the ninth aspect of the present disclosure, it is possible to extend the life of the closed relay using such a coil.

In the closed relay 100 of the tenth aspect of the present invention,
The external volume is 1 cc or more and 100 cc or less.

According to the closed relay 100 of the tenth aspect of the present disclosure, it is possible to extend the life of the closed relay using such a coil.

In the closed relay 100 of the eleventh aspect of the present invention,
The external volume is 1 cc or more and 20 cc or less.

According to the closed relay 100 of the eleventh aspect of the present disclosure, it is possible to extend the life of the closed relay using such a coil.

In the closed relay 100 of the twelfth aspect of the present disclosure, one fixed terminal and one fixed contact may be used instead of the pair of fixed terminals 50 and the pair of fixed contacts 55 shown in FIG. .

The closed-type relay of the present disclosure is used, for example, as an in-vehicle relay.

REFERENCE SIGNS LIST 10 base 20 case 30 coil 40 movable terminal 45 movable contact 50 fixed terminal 55 fixed contact 60 iron core 100 closed relay

Claims (10)

a base to which a movable terminal having a movable contact, a fixed terminal having a fixed contact, and a coil are attached;
a case attached to the base, the case enclosing the movable terminal, the fixed terminal, and the coil in a space defined by the base;
A closed-type relay in which the movable terminal is moved by a magnetic force generated by supplying a current to the coil to bring the movable contact and the fixed contact into contact or non-contact,
at least one of the movable contact and the fixed contact;
40% by weight or more of silver and 1% by weight or more of tungsten and/or tungsten carbide ;
an alternating current is supplied between the movable terminal and the fixed terminal;
A closed type relay characterized by having an external volume of 1 cc or more and 100 cc or less . a base to which a movable terminal having a movable contact, at least one fixed terminal having a fixed contact arranged oppositely across the movable terminal, and a coil are mounted;
a case attached to the base, the case enclosing the movable terminal, the fixed terminal, and the coil in a space defined by the base;
A closed relay in which the movable terminal is moved by a magnetic force generated by supplying a current to the coil, and the movable contact of the movable terminal is brought into contact with the fixed contact of one of the fixed terminals,
at least one of the movable contact and the fixed contact;
40% by weight or more of silver and 1% by weight or more of tungsten and/or tungsten carbide ;
A closed type relay characterized by having an external volume of 1 cc or more and 100 cc or less . at least one of the movable contact and the fixed contact;
3. The closed relay according to claim 1 or 2, comprising 40% by weight or more and 99% by weight or less of silver and 1% by weight or more and 60% by weight or less of tungsten and/or tungsten carbide. at least one of the movable contact and the fixed contact;
3. The closed type relay according to claim 1 or 2, comprising 85% by weight or more and 97% by weight or less of silver and 3% by weight or more and 15% by weight or less of tungsten and/or tungsten carbide. at least one of the movable contact and the fixed contact;
Furthermore, at least one selected from the group consisting of carbon, iron, nickel, cobalt, chromium, molybdenum, copper, tantalum, vanadium, magnesium, zinc, tin, indium, bismuth, palladium, lanthanum, cerium, thorium, yttrium and zirconium 5. The closed type relay according to any one of claims 1 to 4, characterized in that it contains one element as an additive. 3. The closed relay according to claim 2, wherein alternating current is supplied between said movable terminal and said fixed terminal. 7. The closed relay according to claim 1 , wherein the alternating current has an alternating voltage of 50 V or more and 300 V or less and a rated current of 5 A or more and 30 A or less. 8. The closed relay according to claim 1, wherein said coil has a magnetomotive force of 1 ampere-turn or more and 750000 ampere-turn or less. 8. The closed relay according to claim 1, wherein said coil has a magnetomotive force of 1 ampere-turn or more and 300000 ampere-turn or less. The closed type relay according to any one of claims 1 to 9, characterized in that the external volume is 1 cc or more and 20 cc or less.

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