JPH0249615Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Application Field] This invention relates to contact components used in circuit breakers, switches, etc. for electrical equipment, and in particular to composite electrical contact components. [Prior art] Contact parts normally used for circuit breakers, switches, etc. are made by brazing the contacts to the base metal.
The main material of the contacts is silver. However, as it is well known, the price of silver has skyrocketed recently, so expensive
There is an urgent need to reduce the volume of contacts that use Ag as much as possible. [Problems to be solved by the invention] However, simply reducing the volume of the contact points causes the following problems. That is, in contact parts used for circuit breakers, switches, etc., the volume of the base metal is usually considerably larger than the volume of the contact. Therefore, in order to ensure sufficient strength of the joint, it is necessary to maintain the temperature of the base metal high during brazing and to heat it for a long period of time. In addition, due to poor heat balance due to the difference in volume between the contact and the base metal, a stable joint surface cannot be obtained unless a low melting point brazing filler metal (brazing filler metal with a silver content of 40% or more) with a wide heating tolerance is used. becomes difficult to obtain. Furthermore, when heated for a long time, the solid solution layer of silver and brazing material at the contact portion becomes thick. As mentioned above, if contact parts are made of a low melting point brazing filler metal and have a thick solid solution layer, the temperature of the contact will rise due to the arc generated when the equipment is opened/closed, causing the brazing of the contact and base metal. The contact may become misaligned or the contact may fall off. Therefore, it has conventionally been considered impossible to reduce the thickness of the contact point to a certain value or less. Therefore, the present inventor first developed a composite electrical contact component as described below with the aim of providing a contact component that has a reduced thickness and reduced the amount of silver used without deteriorating the contact performance. (Utility Model Application Publication No. 169320/1983). That is, a contact material whose main component is silver, a main metal,
It is a composite electrical contact component characterized by comprising three parts: a metal piece between the main metal base, and joining the three parts with a brazing filler metal to integrate the three members. This is carried out by forming a brazing layer in advance on both sides of the metal piece, for example, by thermal spraying a brazing material, applying a brazing material, or using a tape-shaped brazing material by a soldering method or a placing brazing method. Although the composite electrical contact component obtained by such a method satisfied the above objectives to a certain extent, it was also revealed that it still had the following problems. ○B Quality problems When brazing filler metal is thermally sprayed or coated, it is difficult to control the thickness of the filler metal, and as a result, defects such as wax cracks and blowholes are likely to occur at the bonding interface. In addition, in the case of these methods, including the brazing and placing brazing methods, in order to form the brazing material as a pretreatment layer on both sides of the metal piece, it is necessary to heat and melt it with a burner, etc., and at this time, the metal piece and It was found that a solid solution layer was formed between the filler metals, which had a negative effect on contact performance. B. Problems as a manufacturing method It was found that the above method is difficult to automate, resulting in high manufacturing costs and poor quality stability. In view of the above, the present invention has been developed to solve these problems. [Means for Solving the Problems] The composite electrical contact component of the present invention includes three members: a contact material containing silver as a main component, a main metal, a contact material, and a metal piece between the main metal. In electrical contact parts that integrate three components by joining them with a brazing material, the contact material is a metal piece made of Cu or Cu alloy with copper solder hot-pressed on both sides. It is characterized by being joined to the base metal and integrating three members. Note that the above embodiments include the following. The above-mentioned composite electrical contact component is made by integrating the three components by preliminarily bonding the contact material and a metal piece made of Cu or Cu alloy on both sides of which copper solder is hot-pressed. The above-mentioned composite electrical contact component is made by simultaneously joining the contact material, a metal piece made of Cu or Cu alloy on both sides of which copper solder is hot-pressed in advance, and the main metal to integrate the three components. As mentioned above, in the present invention, a metal piece made of Cu or Cu alloy is used, to which copper solder is hot-pressed on both sides in advance. This brings about the following remarkable effects. A metal piece having a solder layer can be mass-produced by hot pressing such as hot rolling, and it is also possible to automate the manufacturing of contact parts, which can significantly reduce manufacturing costs. Metal pieces with a solder layer are manufactured by hot pressing such as hot rolling, so there is little variation in the thickness of the solder layer, and the surface unevenness is small, so defects such as wax cracks and blowholes in the joining solder layer of contact parts are extremely rare. There are few. Therefore, the quality is stable, and the heat resistance strength, durable short circuit switching performance, etc. as an electrical contact are improved. Although hot press bonding itself is conventionally well known as a means of joining metals, it is possible to apply it to a pre-formed solder layer on both sides of a metal piece as a technology for composite electrical contact parts as in the present invention, and the above-mentioned remarkable effects can be achieved by application. , was not previously known to be effective. Hereinafter, embodiments of this invention will be described based on the accompanying drawings. The contact parts of this invention are as shown in Fig. 1.
It comprises three members: a contact material 1, a metal piece 2, and a main metal 3, the contact material 1 being an alloy containing silver as a main component, and the metal piece 2 being electrolytic copper or an alloy containing copper as a main component. , copper solder 4, 4' is pre-bonded on both sides by hot rolling. These contact material 1, metal piece 2, and main base metal 3 are joined and integrated via copper solder 4, 4', but at this time, contact material 1 and metal piece 2 are preliminarily joined, and these 1, 2 is placed on the main base metal 3 and joined, 1,
2 and 3, or place the contact material 1 and the metal piece 2 on the main metal 3 without pre-bonding them,
Join and integrate 1, 2, and 3. Note that the above bonding is performed, for example, by electric resistance heating. If the thickness of the pre-pressed copper solder layer 4 that joins the contact material 1 and the metal piece 2 exceeds 0.15 mm, the heat diffusivity will decrease and the shear strength of the joint will also decrease. A thickness of mm or less is desirable. Specific examples of the contact material 1, metal piece 2, and brazing filler metal described above are as follows. (Contact material) Ag-CdO-SnO ₂
Cd: 10~25%, _SnO2 : 0.5~5% Ag- _{SnO2 - In2O3}
SnO ₂ : 0.5-10%, In ₂ O ₃ 0.5-15% Ag-graphite Graphite: 0.5-10% (metal piece) Electrolytic copper Cu-Zn Zn: 20-60% Cu-Sn-P
Sn: 2-15%, P: 0.03-0.75% Cu-Ni-Zn Ni: 5-35%, Zn: 5-35% (brazing metal) Cu-P P: 3-8% Cu-P-Ag P :3 to 8%, Ag: 2 to 20% (However, both have a melting point of 700°C or higher) To manufacture the above contact parts, as shown in Fig. 2, the above-mentioned A hoop material pretreated with brazing filler metal by hot pressing is punched out to the same size as the contact using a punching press, and the metal piece 2 and the contact material 1 are cut out to the same size as the contact.
They are overlapped and preliminarily bonded using electrical resistance heating, etc. After a composite is produced by bonding the contact material 1 to the metal piece 2, this is stacked on the main metal 3 and bonded by electrical resistance heating, hot pressure welding, or the like. The composite of the contact material 1 and the metal piece 2 has a sufficient heat capacity, and the heat balance when bonded to the stirrer 3 is good. Next, more detailed examples will be shown. (Example) 1 on both sides of a 50 x 1 x 1000 long electrolytic copper
The surface is Cu-p (P: 7%, melting point 707℃) and other 1
A pretreatment layer is formed on the surface by hot welding of Cu-Ag-P (Ag: 15%, P: 5%), cut into specified dimensions with a slitter, and then cut into 6 x 5 x 1 dimensions. Punch out. After that, contact material Ag− of size 6×5×0.7
CdO- _SnO2 (CdO: 17%, _SnO2 : 2%) was bonded to the pre-treated layer (Cu-P) of the metal piece by electrical resistance heating. Thereafter, another pre-treated layer of the metal piece was layered on the main metal and bonded by electrical resistance heating. Each bonding layer of the contacts thus obtained is 0.05
mm and had good heat resistance. Further, the time required for heating was within 3 seconds, the hardness of the main metal near the contact was 75HRB, and the size of the composite of the contact material and the metal piece was 6 x 5 x 1.7. According to the above embodiments, the bonding layer is extremely thin;
In addition, it was found that the main base metal was hardly dull because it was heat resistant and the heating time was short. (Comparison of heat resistance strength of joints) The shear strength of the joints heated at 900℃ for 5 minutes in a _N2 atmosphere furnace and cooled in a _N2 atmosphere was measured, and the conventional method was compared with that of this invention. . The contact made by the conventional method is made of contact material Ag-CdO-SnO ₂ (CdO: 17%, SnO ₂ : 2) with a size of 6 x 5 x 1.7.
%), and electrolytic copper with a size of 60 x 10 x 2.5 was used as the main metal, and silver solder was used as the joining brazing material. The device based on this invention is made of contact material Ag-CdO-SnO ₂ (CdO: 17%, SnO ₂ :
2%), electrolytic copper with a size of 6 x 5 x 1 was used as the metal piece, and B-CuP was used as the joining brazing material.
The size of the composite obtained by joining is 6×5×
It was 1.7. The main base metal used was the same as that used in the conventional method. The heat resistance strength test results are shown in Table 1.

[Table] From the above results, it was found that the contact according to this invention was superior to the conventional one in terms of heat resistance strength. (Electrical test results) (1) Test target contact A: Contact according to this invention, as listed in (Example). Brazing filler metal for base metal - Cu-Ag-P
(Ag: 15%, P: 5%) Electric resistance heating B: Metal piece - size 6 x 5 x 1, electrolytic copper Contact material - size 6 x 5 x 0.7, Ag-CdO-
SnO ₂ (CdO: 17%, SnO ₂ : 2%) Ag-Cu-Zn-Cd (Cu: 15.5
%, Zn: 16.5%, Cd: 18% - BAG1a) Joining method - Burner heating between metal piece and contact material, electrical resistance heating between metal piece and main metal C: Contact material - Size 6 x 5 x 1.7 ,Ag−CdO−
SnO ₂ (CdO: 17%, SnO ₂ : 2%) Brazing metal - BAG1a Joining method - Electric resistance heating D: Method disclosed in Utility Model Application Publication No. 169320/1983 Contact material: Ag-CdO-SnO ₂ (CdO: 17%,
SnO ₂ : 2%) Size 6 x 5 x 0.7 Metal piece: Size 6 x 5 x 1, electrolytic copper Brazing metal: Cu-P (P: 7%) Between contact and metal piece: Cu-Ag-P ( P: 5%, Ag: 15%) Between metal piece and base metal Brazing metal installation method: Thermal spraying on both sides of the metal piece Joining method with contacts and base metal: Electric resistance heating (same method as the invention of this application) (2) Equipment Wiring sheath breaker (30AF) (3) Test conditions According to product standards. (a to d) In order to make the difference in performance of each contact more clear, e) short circuit test (remaining force) was added. a Overload test Current: 6 times the rated current (180A) Voltage: rated voltage (220V) Number of switching: 50 times <Judgment criteria> No significant contact damage, burnout, welding, or other electrical or mechanical problems should occur. No b Endurance test Current: Rated current (30A) Voltage: Rated voltage (220V) Number of switching: 5000 times <Judgment criteria> Same as overload testc Temperature test Current: Rated current (30A) Voltage: Rated voltage (220V) Energizing Time: Until the temperature becomes constant <Judgment criteria> The temperature rise limit of the contact part must not exceed 100° d Short circuit test (standard) Current: Rated short-circuit current (2500A) Voltage: Rated voltage (220V) Number of switching : O-CO x 2 times <Judgment criteria> - After the test, the rated current can be switched at the rated voltage without any practical problems - The insulation resistance between each terminal and between the conductive part and the earth
Measured with a 500V insulation resistance meter, each 0.5M
Must be Ω or more e Short circuit test (surplus power) Current: Rated short circuit current (2500A) Voltage: Rated voltage (220V) Until short circuit test criteria are not met
Repeat the CO test and measure the number of times. (4) Test effects Table 2 shows the test results.

【table】

[Table] As is clear from these results, the composite contact A of the present invention has improved contact performance such as temperature rise and durability compared to the conventional methods (B, C) and the previously developed method (D). It was found to be excellent and highly reliable (small variation in performance) (Table 2). As shown in Table 3, in the case of the present invention,
Because the brazing filler metal can be formed uniformly and thinly on the surface of the metal piece by hot pressing, the final bonding conditions between the contact and the metal piece, and between the metal piece and the base metal are extremely good (the bonding layer This is thought to be because the film is thin and does not inhibit thermal diffusion.

[Table] [Effects of the invention] As mentioned above, this invention combines the contact material with a metal piece and joins it to the main metal, so the contact material can be saved by the volume of the metal piece. Of course you can. At the same time, the three components, the contact material, the metal piece, and the main metal, are bonded together using a copper solder layer that is hot-pressed on both sides of the metal piece in advance, so that the bonding layer is thin and uniform, and the connection parts are bonded. Since there are no wax cracks or blowholes in the solder layer, it has good thermal diffusivity and high shear strength, making it possible to obtain contacts with excellent performance. Moreover, since the solder layer on the metal piece is formed by hot pressing, manual labor can be omitted, and the manufacturing cost of the contact parts as well as the members is low, and the manufacturing process can be automated.

[Brief explanation of drawings]

FIG. 1 is a sectional view, and FIG. 2 is an explanatory diagram of the manufacturing process. 1...Contact material, 2...Metal piece, 3...Main metal, 4, 4'...Copper brazing layer.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A metal piece made of copper or copper alloy having a contact material mainly composed of silver, a main metal, and a copper solder layer formed by hot pressing on both sides. A composite electrical contact component formed by integrating three components using the copper brazing material. (2) Utility model registration claim No. 1 in which the thickness of the copper solder layer hot-pressed onto the metal piece is 0.15 mm or less.
Composite electrical contact parts described in (1).