JPH08138511A - Electromagnetic relay - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to secure high contact reliability for a long time in a wide range from a medium / light load region to a minute load region. [Configuration] First fixed contact 15a and second fixed contact 15b
A twin fixed contact consisting of a first movable contact 13a and a second movable contact 13a.
A twin movable contact composed of the movable contact 13b, the first fixed contact 15a and the first corresponding contact 13a of the first movable contact 13a, 15a, and the second fixed contact 15b and the second corresponding contact of the second movable contact 13b. Arc resistance with the contacts 13b, 15b,
The first corresponding contact 13 is made of contact materials having different characteristics including welding resistance and corrosion resistance, and is opened and closed.
One of a, 15a and the second corresponding contact 13b, 15b is closed first and then opened later, and the other one is closed later and opened first.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic relay having a fixed contact and a movable contact, each of which is a twin contact.

[0002]

2. Description of the Related Art As a conventional electromagnetic relay, for example, FIG.
There is one shown in FIG. 1 in these figures
Is a frame, 2 is an electromagnet fixed to the frame 1,
3 is a plunger, 4 is a mover connected to the plunger, 5 is a fixed contact base metal fixed to the frame 1, 6 is a fixed contact fixed to the fixed contact base metal 5, and 7 is a mover 4 The movable contact base metal arranged in the support hole 4a, the movable contact base 8 fixed to the movable contact base metal 7, and the spring 9 provided to bias the movable contact 8 toward the fixed contact 6. . The movable contact 8 is formed in a conical shape or an arc shape.
In the electromagnetic relay having the above structure, when the electromagnet 2 is energized, the movable contact 4 of the movable contact base 7 comes into contact with the fixed contact 6 as shown in FIG. In this case, since the movable contact base metal 7 floats from the support hole 4a, the movable contact 8
Contacts the fixed contact 6 by the biasing force of the spring 9.

By the way, the electrical contacts used in such electromagnetic relays and auxiliary relays are generally point contacts, and are easily affected by dust and the like adhering to the contact contact surfaces,
Further, there is a problem that the contact resistance increases due to the formation of an insulating film due to corrosive gas in the environment. For this reason, these have been cited as problems that should be solved in the past,
It is desirable to maintain high contact reliability for a long period of time. Considering this point, when looking at the electrical contacts of the above-mentioned conventional example, it is effective to use twin contacts, and they are often used under a minute load condition. Micro load condition is DC12V,
Since it is considered that the main component is about 24 mA or less,
The electrical contact material used for the twin contacts includes gold (Au),
Noble metal alloys mainly containing noble metals such as platinum (Pt) and palladium (Pd) are used. By making the electrical contacts twin, the number of contact points is generally two, and an increase in contact resistance due to adhesion of dust and the like is improved. Also,
By changing the electrical contact material to a noble metal, it is possible to suppress the formation of insulating coatings due to corrosive gas,
It is possible to maintain high contact reliability for a long period of time. However, since the size of one electrical contact is reduced by making the contactor twin, discharge occurs between the electrical contacts when the electrical contacts are opened and closed depending on the load circuit conditions, and the electrical contacts are consumed. Life becomes shorter,
It becomes difficult to maintain high contact reliability in the long term.
As a measure for extending the life of the electrical contact, it is desirable to use a silver alloy mainly containing silver (Ag) as the electrical contact material. However, when a silver alloy is used for the electrical contacts, an insulating coating film is generated by hydrogen sulfide gas in the atmosphere under a slight load condition where electric discharge does not occur when the electrical contacts are opened and closed, and due to this effect, long-term contact reliability is high. Will be difficult to maintain. As a countermeasure against this, it is conceivable to use a precious metal alloy as the material for the electrical contacts used under micro-load conditions, and use a silver alloy as the material for the electrical contacts used under medium / light load conditions, but this is complicated in practice. Therefore, there is a problem and it cannot be an essential measure.

[0004]

SUMMARY OF THE INVENTION Electromagnetic relays, auxiliary relays, etc. are required to ensure high contact reliability for a long period of time under load conditions at voltages and currents exceeding the rated capacity of built-in electrical contacts. Conventionally, in order to prevent dust and the like from adhering to the electrical contact surface, the dustproof property of the housing of relays, etc. has been improved.Even if dust or the like adheres to the electrical contact surface, the shape and shape of the electrical contact that removes the adhering dust Improvements in the contact method (Japanese Patent Application No. 60-026809) and twinning of electrical contacts have been investigated. However, in recent years, the use load range of electromagnetic relays, auxiliary relays, etc. has been expanding toward the minute load direction, and from the rated load voltage / current region of the electrical contacts (load voltage 200V or 100V, load current number A), It is necessary to ensure high contact reliability for a long period of time under each use condition up to a minute load region (DC 5V, several mA). However, the current electrical contacts such as electromagnetic relays and auxiliary relays have limited applications due to the characteristics of the contact material.If the characteristics of the contact material and the load conditions do not match, high contact reliability is ensured for a long time. It was difficult to do. For example, when the load condition is small and DC 5V and several mA, high contact reliability is secured for a long period of time by using an alloy mainly composed of a noble metal such as gold for the electric contacts and further twinning the electric contacts. It However, when a silver alloy containing silver as a main component is used for an electrical contact, it is difficult to secure high contact reliability for a long time even if the electrical contact is made twin. On the other hand, the load condition is medium / light load (for example, AC100V, 5
In the case of A), when using the above-mentioned gold alloy containing gold as a main component, the electrical contacts are abnormally consumed due to the electric discharge during opening and closing, which causes failure such as inability to open the electrical contacts, and the twinning of the electrical contacts. This tendency becomes more remarkable because the contact points become smaller due to. However, when a silver alloy containing silver as a main component is used for an electrical contact, the occurrence of defects due to abnormal wear as described above is extremely reduced, and long-term contact reliability is secured.

As described above, by using the electromagnetic relay or auxiliary relay currently used, it is used in a wide range of load conditions from the medium / light load region to the minute load region, and high contact reliability is ensured for a long time. Is difficult.

The present invention has been made by paying attention to such a conventional problem, and provides an electromagnetic relay capable of ensuring high contact reliability for a long period in a wide range from a medium / light load region to a minute load region. The purpose is to do.

[0007]

In order to solve the above-mentioned problems, a first aspect of the present invention is to provide a fixed contact composed of twin contacts consisting of a first fixed contact and a second fixed contact, and the first fixed contact. A first movable contact corresponding to the contact and a second movable contact corresponding to the second fixed contact, and a movable contact configured to contact and separate from the fixed contact,
The fixed contact and the first corresponding contact of the first movable contact and the second
The fixed contact and the second corresponding contact of the second movable contact are made of a contact material having different characteristics including arc resistance, welding resistance and corrosion resistance, and the first corresponding contact or the first corresponding contact at the time of opening and closing. The gist is that one of the two corresponding contacts is first closed and then opened later, and the other one is later closed and first opened.

According to a second aspect of the present invention, in the electromagnetic relay according to the first aspect, the first corresponding contact is made of a contact material having at least either arc resistance or welding resistance. The gist of the corresponding contact is that it is made of a contact material having corrosion resistance.

According to a third aspect of the present invention, in the electromagnetic relay according to the second aspect, at the time of opening and closing, the first corresponding contact is first closed and then opened, and the second corresponding contact is later. The gist is that it is configured to be closed and opened first.

The invention according to claim 4 is the same as claims 1 and 2 above.
Alternatively, in the electromagnetic relay according to 3, the arc-resistant contact material is Ag 30 to 70 wt% as a conductive material,
The contact material having at least one of the balance W or WC, the contact resistance material having welding resistance contains at least 85% by weight of Ag as a conductive material, and the balance Ni, CdO, SuO ₂ , Zn.
The contact material made of at least one of O, La ₂ O ₃ and Sb ₂ O ₃ and having corrosion resistance is Pd, P.
A noble metal of any one of t, Au, Ir, Ru, and Ag, a noble metal alloy composed of one of these noble metals as a main component and at least one of the remaining metals, or the noble metal or a base metal containing Cu or Ni in the noble metal alloy. The gist is that it is made of any one of alloys in which at most 15% by weight is added alone or in total.

[0011]

In the invention of claim 1, for example, the first corresponding contact consisting of the first fixed contact and the first movable contact is made of a contact material having arc resistance or welding resistance, and the second fixed contact and When the second corresponding contact made of the second movable contact is made of a contact material having corrosion resistance, the first corresponding contact is first closed and then opened at the time of opening / closing, and the second corresponding contact is opened. By operating it so that it will be closed later and opened first, under the condition of medium and light load where arc discharge etc. occurs at the time of opening and closing, the contact damage prevention due to the arc discharge etc. will be prevented. It is possible to share the contact reliability under the condition of a minute load with the second corresponding contact side, and to make a high contact for a long time in a wide load condition range from the medium / light load region to the minute load region. It becomes possible to secure reliability.

In the invention according to claim 2, the first corresponding contact is made of a contact material having at least either arc resistance or welding resistance, and the second corresponding contact is made of a contact material having corrosion resistance. By making it, when used under medium and light load conditions, the electrical life of the first corresponding contact side is sufficiently long, and it becomes possible to maintain high contact reliability for a long time.
When used under a slight load condition, the contact resistance on the second corresponding contact side is small for a long period of time, and stable and high contact reliability can be maintained.

In the invention according to claim 3, when opening and closing,
A first corresponding contact made of a contact material having at least one of arc resistance and welding resistance is first closed and then opened, and a second corresponding contact made of a contact material having corrosion resistance is left behind. By closing and opening first, the first corresponding contact takes charge of preventing damage to the electric contact due to arc discharge that occurs when opening / closing medium / light loads, and contact reliability during current energization and minute load conditions. The second corresponding contact is shared by the second contact, and it is possible to reliably maintain high contact reliability for a long period in a wide range from the medium / light load region to the minute load region.

In the invention of claim 4, the contact material having arc resistance is Ag 30 to 70% by weight, and the balance W or WC.
At least one of the above, the contact material having welding resistance contains at least 85% by weight of Ag, and the balance Ni, CdO, Su.
At least one of O ₂ , ZnO, La ₂ O ₃ and Sb ₂ O ₃ and a corrosion-resistant contact material is Pd, P
A noble metal of any one of t, Au, Ir, Ru, and Ag, a noble metal alloy composed of one of these noble metals as a main component and at least one of the remaining metals, or the noble metal or a base metal containing Cu or Ni in the noble metal alloy. It is possible to reliably maintain high contact reliability for a long period of time in a wide range from the medium / light load region to the minute load region by using any of the above alloys alone or at most 15% by weight in total.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In FIGS. 1 to 4, the same or equivalent members and parts as those in FIGS. 9 to 12 are designated by the same reference numerals as those described above, and a duplicate description will be omitted. In FIGS. 1 and 2, 14 is a fixed contact, 12 is a movable contact, 11 is a support hole in the mover 4, and as shown in FIG. 4, the bottom portion 11a of the support hole 11 is formed into a predetermined inclined surface. ing. The fixed contact 15 provided on the fixed contact 14 includes a first fixed contact 15a and a second fixed contact 15b.
The first and second fixed contacts 1 are composed of twin contacts consisting of
Each of 5a and 15b is formed in a quadrangle. The movable contact 13 provided on the movable contact 12 is a twin contact composed of a first movable contact 13a corresponding to the first fixed contact 15a and a second movable contact 13b corresponding to the second fixed contact 15b. 1, 2nd movable contact 13a, 13
Each b is formed in a circular shape. 1st fixed contact 1
5a and the first corresponding contact 1 composed of the first movable contact 13a
3a and 15a are made of a contact material excellent in at least one of arc resistance and welding resistance.
b and the second corresponding contact 13 composed of the second movable contact 13b
b and 15b are made of a contact material such as a precious metal having excellent corrosion resistance. The movable contact 12 is, as shown in FIG.
Since the bottom portion 11a of the support hole 11 of the mover 4 is an inclined surface, it is inclined as shown in FIG. 2, and therefore the first and second movable contacts 13a, 13b are also inclined. The first and second movable contacts 13a and 13b are the first and second movable contacts 13a and 13b.
The fixed contacts 15a and 15b are set so as to come into contact with each other substantially at the center.

The opening / closing operation of the electromagnetic relay configured as described above will be described. When the moving element 4 is pulled downward by energizing the electromagnet (see FIG. 9), the movable contact element 12 is also moved downward and displaced, and the first movable contact 13a is first moved.
Comes into contact with the first fixed contact 15a, and then the second movable contact 1
3b contacts the second fixed contact 15b. In this way, the movable contact 13 and the fixed contact 15 are closed. At the time of separation, when the energization of the electromagnet is stopped, the mover 4 returns upward due to the spring force, so that the movable contact 12 also moves upward and is displaced, so that the second movable contact 13b first causes the second fixed contact 1 to move.
5b, and then the first movable contact 13a is separated from the first fixed contact 15a. In this way, the movable contact 13
The fixed contact 15 and the fixed contact 15 are separated from each other.

As described above, the first corresponding contacts 13a and 15a made of the contact material excellent in arc resistance or welding resistance and the second corresponding contact 13 made of the contact material excellent in corrosion resistance.
b and 15b operate with a time lag when closing and opening to prevent damage to the electrical contacts due to arc discharge that occurs during opening and closing under medium and light load conditions, and a contact material with excellent arc resistance or welding resistance. Corresponding first contact 13a, 15
It is shared by a and the life of the electrical contacts is made sufficiently long. On the other hand, the contact reliability under the condition of minute load with small energy such as opening and closing of electric contact without arc discharge and current application to the electric contact is made up of the second contact material made of precious metal or the like which has excellent corrosion resistance. By sharing the corresponding contact points 13b and 15b,
It is possible to secure high contact reliability for a long time in a wide range from the medium / light load region to the minute load region.

Next, the evaluation results will be described by using concrete examples of Table 1 and comparative examples of Table 2. For the evaluation, a load opening / closing operation test (opening / closing of 500,000 times) was performed, and the contact resistance, the number of contact weldings and the contact wear amount under each load condition were performed.

[0019]

[Table 1]

[0020]

[Table 2]

Examples 1 to 3 Ag-CdO was used as a contact material having arc resistance or welding resistance.
(12 wt%) is used, and Au (69 wt%)-Ag (25 wt
%)-Pt, Au (78 wt%)-Ag or Pd (50
wt%)-Ag, as a result, compared to Comparative Example 3 using a single contact of Ag, each characteristic is improved under a load condition of a large current, and the contact resistance is greatly improved under a load condition of a small current. . Also, Au (69 wt%)-Ag (25 wt
%)-Pt only in Comparative Example 4 using a twin contact, under a large current load condition, the welding resistance and contact wear are greatly improved, and the voltage of the load condition targeted in this example is improved. High contact reliability is satisfied in a wide range from high voltage and high current to low voltage and low current. At least 85 wt% of Ag is used as a contact material having welding resistance, the balance is cadmium oxide (CdO), tin oxide (SuO ₂ ), zinc oxide (ZnO), lanthanum oxide (La ₂ O ₃ ) and antimony oxide (Sb _2). O ₃ ) is used as an alloy, and palladium (Pd), platinum (Pt), gold (Au), iridium (Ir), ruthenium (Ru) or Ag is used as a contact material having corrosion resistance. Any one of these noble metals, a noble metal alloy consisting of one of these noble metals as a main component and at least one of the remaining metals, or the noble metal or a noble metal containing Cu or Ni in the noble metal alloy alone or in total at most 15 wt% With any of the added alloys, results similar to the above can be obtained. The above contact material having corrosion resistance can be similarly applied to Examples 4 to 6 and Examples 7 to 8 described below.

Examples 4 to 6 Ag-WC (4) was used as a contact material having arc resistance or welding resistance.
0 wt%) and the same contact material having corrosion resistance as in the case of Examples 1 to 3 above was used. As a result, the contact resistance and welding resistance of Comparative Example 2, Comparative Example 3 and Comparative Example 4 were compared. And the wear resistance were improved, and the object of this example was satisfied. In addition, as a contact material having arc resistance, Ag30 to 70 wt
%, The balance tungsten (W) and / or tungsten carbide (WC) can be used to obtain substantially the same results as above.

Examples 7 to 8 Ag-Ni (1) was used as a contact material having arc resistance or welding resistance.
0 wt%) and the same contact material having corrosion resistance as in Examples 1 and 2 was used, and as a result, each characteristic was improved as compared with Comparative Examples 3 and 4, and the purpose of this Example was to Satisfied.

[0024]

As described above, according to the first aspect of the present invention, the fixed contact constituted by the twin contact composed of the first fixed contact and the second fixed contact and the first fixed contact are provided. A first movable contact and a second movable contact corresponding to the second fixed contact, and the movable contact is configured to contact and separate from the fixed contact, and the first fixed contact and the first movable contact And the second corresponding contact of the second fixed contact and the second movable contact are made of contact materials having different characteristics including arc resistance, welding resistance and corrosion resistance, Since either one of the first corresponding contact or the second corresponding contact is closed first and opened later, the other one is closed later and opened first,
Under conditions such as medium or light load where arc discharge is generated during opening and closing, either the first corresponding contact or the second corresponding contact is responsible for preventing damage to the contact due to the arc discharge, etc. The contact reliability at the time of 1st corresponding contact or 2nd
It is possible to share one of the corresponding contacts with the other contact, and it is possible to secure high contact reliability for a long time in a wide load condition range from a medium / light load region to a minute load region.

According to the second aspect of the invention, the first corresponding contact is made of a contact material having at least either arc resistance or welding resistance, and the second corresponding contact is corrosion resistant. Since it is made of the contact material, it has a sufficiently long electrical life on the first compatible contact side when used under medium and light load conditions, and can maintain high contact reliability for a long period of time. In this case, the contact resistance on the side of the second corresponding contact is small for a long period of time, and stable and high contact reliability can be maintained.

According to the invention of claim 3, at the time of opening and closing, the first corresponding contact is first closed and then opened.
Since the second corresponding contact is configured to be closed later and to be opened first, the first corresponding contact shares the damage prevention of the electric contact due to the arc discharge generated at the time of opening / closing the medium / light load,
The contact reliability under current application and under minute load conditions is shared by the second corresponding contact, and high contact reliability can be reliably maintained for a long period in a wide range from the medium / light load region to the minute load region.

According to the fourth aspect of the invention, the arc-resistant contact material is Ag30-70 as a conductive material.
%, And the balance W and / or WC,
The contact material having the welding resistance is A as a conductive material.
g is at least 85% by weight, balance Ni, CdO, SuO
_2, ZnO, comprising at least one of a La ₂ O ₃ and Sb ₂ O _3, the contact material having the corrosion resistance P
a noble metal of d, Pt, Au, Ir, Ru or Ag, a noble metal alloy containing one of these noble metals as a main component and at least one of the other metals, or Cu, Ni in the noble metal or the noble metal alloy. It is possible to reliably maintain high contact reliability for a long period of time in a wide range of medium / light load region to minute load region, because the base metal containing is used alone or as an alloy containing at most 15% by weight in total. it can.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of an electric contact portion in an embodiment of an electromagnetic relay according to the present invention.

2 is a vertical side view of FIG.

3 is a vertical cross-sectional side view in the closed state of FIG.

FIG. 4 is a side view of a mover portion in the above embodiment.

FIG. 5 is a diagram showing a movable contactor portion in the above embodiment.

FIG. 6 is a view showing a fixed contact portion in the above embodiment.

FIG. 7 is a vertical sectional front view of a conventional electromagnetic relay.

FIG. 8 is a vertical sectional front view of an electric contact portion in the above conventional example.

9 is a vertical side view of FIG.

10 is a vertical cross-sectional side view in the closed state of FIG.

[Explanation of symbols]

 12 movable contact 13 movable contact 13a, 13b 1st, 2nd movable contact 14 fixed contact 15 fixed contact 15a, 15b 1st, 2nd fixed contact

Claims (4)

[Claims] 1. A fixed contact composed of twin contacts composed of a first fixed contact and a second fixed contact, a first movable contact corresponding to the first fixed contact and a second movable contact corresponding to the second fixed contact. A movable contact configured to be a twin contact made of a contact, the movable contact being in contact with and separated from the fixed contact, the first corresponding contact of the first fixed contact and the first movable contact, and the second fixed contact and the second movable contact. The second corresponding contact is made of a contact material having different characteristics including arc resistance, welding resistance and corrosion resistance, and either the first corresponding contact or the second corresponding contact is opened or closed. An electromagnetic relay characterized in that the electromagnetic relay is configured such that it is first closed and subsequently opened, and the other one is later closed and first opened. 2. The first corresponding contact is made of a contact material having at least either arc resistance or welding resistance, and the second corresponding contact is made of a contact material having corrosion resistance. The electromagnetic relay according to claim 1, wherein: 3. When opening and closing, the first corresponding contact is first closed and then opened later, and the second corresponding contact is later closed and opened first. The electromagnetic relay according to claim 2, wherein: 4. The contact material having arc resistance is composed of 30 to 70% by weight of Ag as a conductive material and at least one of the balance W or WC, and the contact material having welding resistance serves as a conductive material. At least 85 wt% Ag,
Balance _{Ni, CdO, SuO 2, ZnO} , comprising at least one of a La ₂ O ₃ and Sb ₂ O _3, the contact material having the corrosion resistance Pd, Pt, Au, Ir, Ru
Or a noble metal of Ag, a noble metal alloy composed of one of these noble metals as a main component and at least one of the remaining metals, or the noble metal or the noble metal alloy with C
u or Ni base metal alone or in total at most 1
The electromagnetic relay according to claim 1, wherein the electromagnetic relay is made of any one of alloys added with 5% by weight.