KR100473425B1 - An electromechanical relay and method of manufacturing same - Google Patents

Abstract

The present invention relates to a movable contact arm for an electromechanical relay, in particular for a relay. The contact arm is produced by brazing a pair of contact pieces with metal blades from both sides. The metal blade has through-holes so that extra brazing material does not contaminate the contact surfaces, and the contact pieces are centered from both sides on these through-holes. The through-hole serves as a braze reservoir. Therefore, the brazing material that enters the extra brazing material into the hole restricts the flow of the braze over the contact edge, which causes contamination of the contact surface.

Description

Electromechanical relay and manufacturing method thereof {AN ELECTROMECHANICAL RELAY AND METHOD OF MANUFACTURING SAME}

The present invention relates to an electromechanical switching device such as a relay. In particular, the present invention relates to an electromechanical switching device having contact pieces on both sides thereof and having, for example, an electrical contact arm used as a movable contact arm.

In relays and other electromechanical switching devices that switch high currents, riveted contacts are typically used in the manufacture of electrical contact arms. For example, for a contact configuration (eg SPDT, Break-Make, Form C) with a central contact arm requiring contact on both sides, rivet contact for this arm is performed and then laminated through holes in the arm. And must be deformed again to achieve a mating contact surface on both sides of the contact arm. This known method of making contact arms is expensive to produce contact rivets. Moreover, the final contact arm structure does not pass the rather stringent application life requirements for a particular switching application.

GB-A-1,158,119 describes a spring blade assembly having a plurality of overlapping spring blades clamped together through a connected contact piece located on one side of a plurality of spring blades and a method of manufacturing the same. will be. In particular, the spring blade has an aligned opening formed therethrough, a head contact overlying the opening on one side of the plurality of spring blades and a backing member overlying the opening on the other side. The head contact and the reinforcing member are connected to each other by soldering or welding. Due to the plurality of overlapping spring blades, the contact pieces must be well connected in the aligned openings. Because of this, each contact piece needs to have a connecting member extending from the head contact and / or reinforcing member into each opening for joining to the other contact piece. As a result, the contact pieces have a rivet form and are expensive to manufacture, as with the rivet contacts described above.

It is known to bond the contact piece to the surface of the electrical contact arm by metallurgical bonding, such as resistance brazing, as desired, such as cutting the contact piece from the contact tape. Holes need not be formed in the surface of the contact arm. Such contact pieces typically have a braze alloy backing layer on one side, which layer is used to braze the contact piece on the flat surface of the contact arm or spring blade. Contact arms made from brazed contact tape pieces typically pass stringent application life requirements.

However, during the bonding / brazing process, the dissolved extra brazing material flows on the side of the contact piece and in some cases flows onto the surface of the contact piece. This is due, in part, to the electrodes used in the brazing process that force the contact piece to hold it in place to ensure satisfactory electrical contact with the contact arm. This condition can result in not only welding of the contact during operation of the contact arm, but also shortening the resistance brazing process electrode life. Not beneficially, the thickness or amount of the braze alloy coating cannot be sufficiently reduced due to restrictions in the manufacturing process of the contact tape. That is, such braze alloy coatings can be achieved with only a certain minimum thickness on the tape.

1 is a schematic illustration of the method of the present invention using different scales in which the contact piece is cut from the tape and placed in the center of both sides of the metal blade;

2 is an enlarged cross sectional view of the electrical contact arm of the present invention with a contact piece at the beginning of the brazing process;

3 is a cross sectional view of the contact arm of FIG. 2 with the contact piece after brazing;

4 is an exploded view of the relay of the present invention.

5 shows a movable contact arm of the relay of FIG.

Therefore, it is an object of the present invention to overcome the disadvantages of the prior art.

In particular, it is an object of the present invention to provide an electromechanical switch having an electrical contact arm using an inexpensive contact piece having a simple shape and a flat bottom surface, the contact piece being a metal blade without extra brazing material affecting the contact surface. It can be brazed on both sides of.

It is a further object of the present invention to provide an electromechanical switch having an electrical contact arm in which a pair of contact pieces are cut from a contact tape having a brazing alloy reinforcement.

Another additional object of the invention is that a pair of contact pieces are brazed on each side of the metal blade and the contact is pressed against the metal blade to achieve a predetermined overall thickness between the contact surfaces without having to remove the extra brazing material. An electromechanical switch having an electrical contact arm is provided.

The above-mentioned problems are eliminated by the present invention, and the present invention,

A coil assembly having a magnetic core, a coil wound around the core, and a frame holding the coil and the core;

(a) a pair of stationary contact arms arranged opposite to each other and having respective contacts facing each other; And (b) a contact assembly having a metal blade having a through-hole formed therethrough and a pair of contact pieces each having a flat bottom surface and having a movable contact arm arranged between the pair of stationary contact arms, A contact assembly, wherein the contact piece is brazed to the bottom surface of the metal blade to cover the through-hole from both sides and the through-hole is at least partially filled with extra braze material; And

Provided is an electromechanical switch comprising means for actuating a movable contact arm upon energizing the coil and upon disconnection of the power.

The present invention also provides an electrical contact arm comprising a metal blade having through-holes formed therethrough, and a pair of contact pieces each having a flat bottom surface, the contact piece receiving the through-holes from both sides. A bottom surface is bonded to the metal blade to cover it and the through-hole is at least partially filled with extra bonding material.

Moreover, the present invention provides a method of making an electrical contact arm, the method comprising:

Providing a metal blade having a through-hole formed therein;

Providing a pair of contact pieces each having a flat bottom surface that is larger than a through-hole in the metal blade, each of the bottom surfaces being coated with a layer of bonding material;

Positioning one of the contact pieces on one side of the blade to cover the through-hole from one side;

Bonding the contact piece to the blade by applying heat to dissolve the layer of bonding material while pressing the contact piece from one side against the blade, wherein the through-holes are The bonding step serving as an incoming reservoir; And

Solidifying the bonding material.

In order to better understand the present invention, reference is made to the following detailed description of exemplary embodiments of the present invention and the accompanying drawings.

Referring now to FIG. 1, a contact tape 1 is shown which is typically wound on a spool 2. The contact tape 1 has a certain thickness and width. In order to produce the electrical contact arm, the tape 1 is cut into a single contact piece 3. The cutting mechanism 4 is shown schematically only and can be any type of known or conventional cutting mechanism. The contact tape 1 is made of a contact material and coated on one side with a braze alloy reinforcement. For example, as shown in the figure, the contact tape 1 and the contact piece 3 have three bonded layers: a paired precious metal surface layer 31, a silver intermediate layer 32 and a braze alloy reinforcement layer. 33, these layers are shown in enlarged cross section.

For example, to produce an electrical contact arm that can be used as a movable contact arm for a relay and having contacts on both sides, the metal blade 5 has a through-hole 6 in the desired contact position. The metal blade 5 can be made of any material suitable for the desired application, for example copper alloy. Then, a pair of cut contact pieces 3A, 3B having a braze stiffener layer 33 positioned against the blade 5 is centered on both sides of the through-hole 6. Each contact piece 3A, 3B has a larger cross-sectional area than the through-hole 6 so that the through-hole 6 is completely covered on both sides of the metal blade 5 and the contact pieces 3A, 3B are made of metal blades ( 5) Contact each peripheral surface.

As shown in FIG. 2, the pair of electrodes 7, 8 leads to the paired surface layer 31 of the contact pieces 3A, 3B. Electrodes 7 and 8 exert a force on contact pieces 3A and 3B to keep the pieces in place so that they are in satisfactory electrical contact with metal blade 5. Then, for a sufficient amount of time, a current is passed through the first electrode 7, the metal blades and the contact assemblies 3A, 5 and 3B to the other electrode 8 on the two contact pieces 3A, 3B. The braze alloy reinforcement 33 is dissolved. The amount of current applied depends on the components and other physical properties of the various elements.

After the current is interrupted, the electrodes 7, 8 can remain in place for a sufficient time so that the braze alloy can solidify. This method allows each of the contact pieces 3A, 3B to be brazed directly to the blade 5 and any extra braze material 34 is introduced into the through-hole 6 which serves as a "braze reservoir". . Once the braze has solidified, the electrodes 7, 8 are removed as shown in FIG.

If desired, the method may also allow the contact pieces 3A, 3B to be joined together. This can be accomplished by completely filling the through-holes 6 with the extra braze material 34 (as shown in FIG. 3) or by allowing the extra braze material 34 from each contact piece to pass through each other in the through-holes 6. It can be achieved by fully bonding.

As an example, a movable contact arm for a relay has been manufactured using the method of the present invention having the following size:

Contact pieces 3A, 3B: length and width 3.5 mm;

The thickness of the paired precious metal surface layer 31: 0.46 mm (min);

Thickness of intermediate layer 32 of silver: 0.12 mm (max);

The thickness of the braze alloy reinforcement layer 33: 0.02 mm to 0.04 mm;

Thickness of the contact arm blade 5: 0.127 mm;

Diameter of the through-hole (6): 2.39 mm

The braze alloy stiffener layer 33 is made of conventional braze alloy components, such as 15% Ag, 80% Cu and 5% P.

4 shows a relay 40 of the present invention. The relay 40 contacts the base 41, the coil assembly 42 connecting to the base 41, the armature 43, the stationary contact members 44 and 45 and the stationary contact members 44 and 45. In order to be movable by the armature 43. The movable contact arm 46 is shown in more detail in FIG. 5. The moving contact arm 46 includes a metal blade 46a having a through-hole 46b formed therethrough and a pair of contact pieces 46c and 46d joined to the metal blade 46a. The through-hole 46b serves as a reservoir containing any extra bonding material used to join the contact pieces 46c and 46d to the blade 46a. The relay 40 and the movable contact arm 46 can be configured by the method of the present invention.

The embodiments described herein are merely illustrative of the principles of the present invention. Various changes may be made by those skilled in the art without departing from the scope and spirit of the invention.

For example, the contact tape 1 may be in the form of a single strip rather than the spool 2. In addition, the contact pieces 3A, 3B can be cut from the tape 1 in various forms, for example rectangular or circular. In addition, the braze alloy stiffener layer 33 may be made of any known or conventional brazing material.

Moreover, the braze alloy reinforcement layer 33 can be dissolved using a mechanism other than using the electrodes 7, 8 and applying a current therebetween, for example, a heat chamber. Moreover, the electrodes 7, 8 can be replaced or supplemented by other mechanisms for pressing and holding the contact pieces 3A, 3B against the metal blade 5.

Moreover, the contact pieces may also be bonded to the blade via any known or conventional metallurgical joining process, such as soldering or welding, in addition to brazing, using suitable soldering or joining materials.

Claims (19)

In the manufacturing method of the electrical contact arm, Providing a metal blade (3; 46a) having a through-hole (6; 46b) formed therein; Providing a pair of contact pieces (3; 46c; 46d) each having a flat bottom surface larger than the through-holes (6; 46b) in the metal blades (3; 46a), each of the bottom surfaces being a bonding material Providing a contact piece, coated with a layer (33) of; Positioning one of the contact pieces (3; 46c; 46d) on one side of the metal blade (3; 46a) to cover the through-hole (6; 46b) from one side; The metal blades 3; 46a by applying heat to dissolve the layer of the bonding material 33 while pressing the contact pieces 3; 46c; 46d from one side against the metal blades 3; 46a. Bonding the contact piece (3; 46c; 46d) to the contact piece (6; 46b), wherein the through-hole (6; 46b) serves as a reservoir into which the dissolved extra bonding material (34) is introduced; And Solidifying the bonding material. The method of claim 1, The bonding material comprises a brazing material 33 and the contacting piece (3; 46c; 46d) bonding step comprises brazing the contact piece (3; 46c; 46d). Way. The method of claim 2, Making the contact piece 3; 46c; 46d from the tape 1 made of the contact material 31 coated with the brazing material 33 on one side. Way. The method of claim 2, The brazing step comprises the step of providing resistive heating by providing a pair of electrodes (7,8) to the pair of contact pieces (3; 46c; 46d) and passing a current therebetween. Cancer manufacturing method. The method of claim 4, wherein The electrodes 7, 8 are arranged to press and hold the contact pieces 3; 46c; 46d against the metal blades 3; 46a until the brazing material 33 solidifies. Electrical contact arm manufacturing method. The method of claim 1, And said solidifying step comprises cooling said contact piece (3; 46c; 46d). The method of claim 2, The brazing step is performed by the brazing material 33 until there is sufficient excess brazing material 34 dissolved in the through-holes 6; 46b to braze the contact pieces 3; 46c; 46d. And dissolving the layer. delete delete delete delete delete delete delete delete delete delete delete delete