EP1025573B1 - Method for producing a relay - Google Patents

Abstract

A coil form (1) is injection moulded to form the base body of the relay. At least one fixed contact carrier (3,4), one contact-spring contact pin (5) and coil contact pins (9,10) embodied as wire sections in the form of drawn semi-finished products are introduced into the mould and extrusion-coated. The core (16) can also be embedded into the material of the coil form (1) if so desired. This dispenses with assembly processes involving the abrasion of plastic particles which can later become deposited on the contacts. All connector pieces can be mounted in a cost-effective manner in the injection mould, requiring as little material as possible by virtue of the fact that there is no wastage when the semi-finished wires are separated.

Description

The invention relates to a method for producing a Relay, which has a coil body with a coil tube, two Coil flanges and a winding, a core with an L-shaped Yoke, an anchor connected to a contact spring and a connector pin for the contact spring and at least has a first fixed contact carrier with a fixed contact.

Such a relay is constructed, for example, from the US 4,596,972. The contact spring encloses it in an arc the anchor bearing and is with its connecting section attached to the yoke, the yoke in turn one down integrally formed connector pin. With such relays, at which the load current is led over the yoke is the Current path in the relay for connection relatively long; Moreover is the ferromagnetic yoke material in its conductivity limited. This affects the switching capacity higher Flows then unfavorable, even if the pin with its relatively small cross section made of the same material is made. In addition, a molded on yoke is required Connector pin an extra hassle when the relay housing to be sealed.

With relays of similar design, designed for high load currents are, it is also known to load current from one in a connector pin attached via a copper wire directly to the contact spring and to the attached to it Lead contact piece (DE 34 28 595 C2). In this way the yoke does not need to carry the load current. The stake however, the strand requires additional material and assembly effort.

In these known relays, the fixed contact carriers and if necessary, the contact spring connector pin each manufactured as stamped parts and by plugging in preformed shafts and openings of the coil body or a base and then by a notching process or determined by self-pressure. This structure has the disadvantage that the parts either for tolerance reasons not stuck positively in the plastic part or that at during assembly due to overlapping of parts, particles are rubbed off become. These particles can later in the relay, for example on the contacts, in the anchor bearing or in the working air gap, lead to problems. A high level must then be used in production Effort to be driven through the resulting particles To eliminate blowing or suction devices.

With other relays, it is known to use individual parts, such as contact carriers, stamped from sheet metal and either individually or in To overmold strips in a mold. This The type of production has the disadvantage that the parts in the Injection mold must be inserted; also required the strip production a high material consumption. In both Cases require a lot of effort to get the injection mold to adapt to the punching tools to ensure a good seal the shape in the area of the punch burrs.

The aim of the present invention is a method with which a relay of the type mentioned particularly simple and can be produced with few parts. In particular, this should Process the use of particularly cheap semi-finished materials can be carried out in a material-saving and waste-free manner, which makes the relay particularly economical and still with high quality is produced.

a)der Kontaktfeder-Anschlußstift, der mindestens eine Festkontaktträger und die Spulenanschlußstifte werden als Abschnitte jeweils eines Draht-Halbzeugs in eine Spritzgießform vorgeschoben und dort fixiert;

b)durch Einspritzen von Kunststoff in die Spritzgießform wird der Spulenkörper derart ausgeformt, daß in einem ersten Spulenflansch ein Schaltraum gebildet wird, wobei der mindestens eine Festkontaktträger im Bereich des Schaltraums in den ersten Spulenflansch und der Kontaktfeder-Anschlußstift ebenfalls in einen der Flansche eingebettet wird;

c)die Draht-Abschnitte werden vor oder nach dem Einspritzvorgang von ihrem jeweiligen Halbzeug abgetrennt;

d)auf den mindestens einen Festkontaktträger wird ein Festkontakt aufgeschweißt oder hartgelötet;

e)der Spulenkörper wird mit der Wicklung, dem Kern und dem Joch derart versehen, daß ein freies Jochende eine Lagerkante für den Anker bildet;

f)der plattenförmigen Anker wird an der Lagerkante derart gelagert, daß die Kontaktfeder mit einem abgewinkelten Abschnitt die Lagerstelle umschließt und mit ihrem kontaktgebenden freien Ende dem mindestens einen Festkontakt gegenübersteht, und

g)ein Anschlußabschnitt der Kontaktfeder wird mit dem Kontaktfeder-Anschlußstift verbunden.

According to the invention, this goal is achieved with the following process steps:

a) the contact spring connector pin, the at least one fixed contact carrier and the coil connector pins are advanced as sections of a wire semi-finished product in an injection mold and fixed there;

b) by injecting plastic into the injection mold, the coil body is shaped such that a switching space is formed in a first coil flange, the at least one fixed contact carrier in the area of the switching space being also embedded in one of the flanges in the first coil flange and the contact spring connecting pin ;

c) the wire sections are separated from their respective semi-finished products before or after the injection process;

d) a fixed contact is welded or brazed onto the at least one fixed contact carrier;

e) the coil body is provided with the winding, the core and the yoke such that a free yoke end forms a bearing edge for the armature;

f) the plate-shaped armature is mounted on the bearing edge in such a way that the contact spring encloses the bearing point with an angled section and faces the at least one fixed contact with its contacting free end, and

g) a connection section of the contact spring is connected to the contact spring connection pin.

The inventive use of semi-finished wire for the load circuit connections result in a particularly inexpensive and material-saving manufacture of the relay. Since that Semi-finished wire products directly from the supply roll into the Injection mold is inserted and embedded there no punching or bending tools required. Also the coil connections used in the usual way are on the molded in the same way with the mold. The wire can either before overmolding or immediately after overmolding be separated by the injection mold, whereby none Waste arises. Through the use of drawn wires with a simple, preferably round or rectangular Profile is also easy to seal the injection mold, since no punch burrs or the like are taken into account have to. Since the relay has no punched parts, no plastic particles are scraped off during assembly, which are on the contact surfaces or pole faces deposit and impair the function of the relay. Due to the low tolerances of the drawn semi-finished wires with angular or round cross-section and the unproblematic precisely producible, geometrically simple openings in the Injection mold or spray skin or burr formation is avoided. For a positive tight fit of the straight wires in the thermoplastic molded part, it is useful if a or several sides of the wires with a knurling or with Notches are provided, which are inexpensive in the usual knurling roll pass are producible.

In the simplest configuration, the relay has only one Fixed contact with the contact spring as a make or break contact cooperates and accordingly on one or the other Side of the spring end arranged with the movable contact becomes. In the same way, a changeover contact can also be used are generated, in which case a second fixed contact carrier embedded in the bobbin opposite the first one and is provided with a fixed contact.

In an advantageous embodiment, the contact spring connector pin just like the fixed contact carrier a square wire formed. In this case, the contact spring on the one hand and the fixed contacts on the other large transition area welded or soldered to the carrier become. The fixed contacts themselves are also preferably separated as sections from a semi-finished contact tape, so that there is no waste here either.

In a preferred embodiment of the method according to the invention the two fixed contacts are or soldering device on the two fixed contact carriers attached by an inner electrode between the two Fixed contacts arranged and two outer electrodes on the two Fixed contact carriers are created so that the thickness of the Internal electrode the predetermined distance between the two fixed contacts equivalent. In this way, calibration is achieved of the contact distance, preferably one at the Fixed hard solder layer melted during the soldering process and more for adjusting the contact distance or less displaced.

In a preferred embodiment of the invention, too the contact spring connector pin in the first coil flange, i.e. embedded in the area of the control room, and the connection section the contact spring is directly on one section of the yoke parallel to the bearing edge of the yoke Pin attached. The anchor lies with its end of the bearing in this case between the yoke end and the connecting pin, while the connection section of the contact spring on the Bearing end of the armature passed over to the connecting pin and on attached, preferably welded or brazed, becomes.

The core arranged in the coil tube preferably has one Pole plate with eccentrically enlarged towards the armature bearing Pole face. This means that even with small relay dimensions on the one hand, an adequate isolation distance from the fixed contacts and on the other hand generates a sufficiently large pole area become. In an advantageous embodiment, the Core embedded in the manufacture of the bobbin be, so that a subsequent plugging process is not necessary. In this case the core can be round or round have a rectangular cross section. It is also possible to retrofit a round core into a through opening of the bobbin. In this case it is advantageous, on the core surface near the pole plate stamped warts to be provided for later relaxation of the thermoplastic coil body material a positive connection form and thus a mutual fixation of the core pole surface and the bearing edge of the yoke.

In an advantageous embodiment of the invention is furthermore provided that the contact spring with the anchor bearing angularly enclosing fastening section is attached to the yoke and that one over the attachment portion folded connector section to the connector pin is managed and connected to it. In this way a relay for high load currents ensures that a large spring cross section for guiding the load current until the pin is available.

By embedding all load connections in the area of one Coil flange, the connections are already tight the floor of the control room led down. One on the cap placed on the coil former only needs to be along the outer contour of the coil flange to be sealed. The same applies to the opposite second Flange where an injected coil connector pin also is already tightly embedded. So it only remains Space underneath the coil winding, which is easy to use closed a plate and sealed along the edges can be.

Figur 1 ein erfindungsgemäß hergestelltes Relais in perspektivischer Darstellung (ohne Gehäusekappe),

Figur 2 das Relais von Figur 1 in teilweise montiertem Zustand (mit Gehäuse),

Figur 3 das fertig montierte Relais von Figur 1 in einem Horizontal-Längsschnitt,

Figur 4 einen steckbaren Kern für das Relais gemäß Figur 2,

Figur 5 einen Vertikal-Längsschnitt durch das Relais von Figur 1 mit einem Kern gemäß Figur 4,

Figur 6 eine schematische Darstellung einer Anordnung zur Durchführung des erfindungsgemäßen Herstellungsverfahrens für ein Relais gemäß den Figuren 1 bis 5 und

Figuren 7 und 8 eine schematische Darstellung für das Aufbringen der Festkontakte in zwei verschiedenen Verfahrensstadien bei dem Relais gemäß Figuren 1 bis 5.

The invention is explained in more detail below using exemplary embodiments with reference to the drawing. It shows

FIG. 1 shows a relay produced according to the invention in perspective view (without housing cap),

FIG. 2 shows the relay from FIG. 1 in a partially assembled state (with housing),

FIG. 3 shows the fully assembled relay from FIG. 1 in a horizontal longitudinal section,

FIG. 4 shows a plug-in core for the relay according to FIG. 2,

FIG. 5 shows a vertical longitudinal section through the relay from FIG. 1 with a core according to FIG. 4,

Figure 6 is a schematic representation of an arrangement for performing the manufacturing method according to the invention for a relay according to Figures 1 to 5 and

FIGS. 7 and 8 show a schematic illustration for the application of the fixed contacts in two different process stages in the relay according to FIGS. 1 to 5.

The relay shown in Figures 1 to 5 has as a load-bearing Part of a coil former 1 with a coil tube 11, a first flange 12 and a second flange 13. The first Flange 12 forms an extension into which a control room 14 is molded, which is closed at the bottom with a bottom 15 and thus defines the connection side of the relay. A winding 2 is attached to the coil tube 11.

In the extension of the first flange 12 are two fixed contact carriers 3 and 4 and a contact spring pin 5 embedded by overmoulding, which is made from highly conductive semi-finished products Material, for example copper, as square wire are executed. Instead of the wire shown with square Cross section could also be one with rectangular or with round cross section can be used. The two fixed contact carriers are with each other on the facing surfaces provided a fixed contact, namely a first fixed contact 6, which acts as a make contact, and with one second fixed contact 7, which serves as a break contact. These contacts are each made as contact pieces from a semi-finished contact material band cut off and attached to the fixed contact carrier 3 or 4 welded or (preferably) brazed.

Two other wires, preferably with a smaller cross section are as coil pins 9 and 10 in the second and in first flange arranged diagonally offset and in the same Embedded like the load connections. These coil connector pins are preferably of square cross-section run to better tightening the winding of the Reach winding ends before their material connection. This connection is preferably made by means of a TIG welding or TIG soldering, in which a flux-free and therefore particle-free connection is achieved.

There is a round or rectangular one in the coil tube 11 soft magnetic core 16 with an integrally molded Pole plate 17, one side of whose contour along a segment line 18 is separated. This gives you a big one Pole surface, especially on the one facing the armature bearing Side while on the opposite side a big enough Isolation distance to the fixed contact carrier 3 is guaranteed. The core end 19 opposite the pole plate 17 protrudes the coil tube and is with an arm 20a of an L-shaped Yokes 20 connected. Whose second leg 20b extends laterally parallel to the coil axis and forms at its end a bearing edge 21 for an armature 22.

The core 16 can be formed when the coil former 1 is formed these, that is to say embedded in the coil tube 11, so that the later insertion is not necessary (see Figure 3). In this In this case, the core end protruding over the coil former serves 19 for centering the core in the injection mold.

In order to ensure the burn-off safety (the Overstroke) of the armature for the life of a normally open contact to ensure, the anchor has in the area below a free stamping 22b of the movable contact spring end, so that between the contact spring 23 and the armature 22 a Air gap 28 arises. Through side constrictions 22c also specified a predetermined bending point. It enables one Increasing the overstroke when the armature is under force the coil axis is slightly bent.

However, it is also possible to retrofit the core according to FIG. 2 to insert into the coil tube. In this case it is advantageous close to the circumference of the cylindrical core of the pole plate 17 warts 16a, as shown in the figures 4 and 5 is shown. These protruding warts 16a are in the assembled state with an oversize in the area of the coil flange 12 and result in the later relaxation of the Thermoplastic material a positive connection; this will fix the position the core pole face on the pole plate 17 and the Bearing edge 21 of the yoke in the coil body and thus opposite reached the fixed contact carriers embedded in the coil body. Because the core and the yoke, for example by a Notch connection, so connected in the region of the coil flange 13 that the pole face of the pole plate 17 and the yoke bearing edge 21 are aligned, tolerances of both parts turned off and an optimal magnetic attraction reached for the anchor. The compensation of the tolerances and thus the adjustment of the overstroke is realized in such a way that the notched yoke-core unit in the coil tube so is pushed far in the axial direction until the overstroke the armature reaches its setpoint. Here, the change optimizes aligned surfaces in the working and anchor bearing air gap not in their mutual assignment; only the magnet system the position of the contact set is adjusted. By the additional action of forces F on opposite Sides of the coil flange 12 (see Figure 5) vertically the relaxation of the thermoplastic to the coil axis Bobbin material are accelerated, making the tight fit of the core in the region of the flange 12 after the adjustment becomes.

With the armature 22 is a contact spring 23 via a rivet point 24 connected, which at their protruding above the anchor End 23a carries a movable contact 25, which acts as a center contact cooperates with the two fixed contacts 6 and 7. As in the example shown, it can be a riveted contact or by two welded together or soldered contact pieces separated from a precious metal strip be formed. Has in the area of the anchor bearing the contact spring 23 has an attachment portion 23b which is shown in FIG Form a curl or loop over the stored end of the anchor bent and lying flat on the yoke leg 20b Rivet warts 26 or by resistance or laser welding is attached. Due to its pretension, this creates Attachment portion 23b of the contact spring, the armature restoring force. In addition, the contact spring 23 has a Fastening section 23b extending connecting section 23c which extends 180 ° over the fastening section 23b is folded and with its end on the pin 5 through Welding or brazing is attached. This connection section the spring is only used to conduct electricity and has none Influence on the restoring force of the armature. He is in the area the rivet warts 26 or welding spots are provided with openings 27, so that it is not riveted or welded. The armature 22 has a securing lug for shock protection 22a, which is punched into the fastening portion 23b Rectangular hole 23d protrudes and the armature in the axial direction Coil secures.

The previously described open circuit board relay according to FIG 1 can be provided with a protective cap 29 according to FIG. 2 become. In addition, in the area of the bottom side between a bottom plate 30 is used for the two flanges 12 and 13 that covers the coil winding space downwards. Subsequently can the gap between the cap 29, the bottom plate 30 and the bobbin 1 by a potting compound be sealed. The base plate covering only the coil space 30 does not cause particle abrasion since the wire-like Connections, namely the fixed contact carrier 3 and 4, the Contact spring connector pin 5 and the coil connector pins 9 and 10, are embedded in the flanges and no breakthroughs need in the base plate. The bottom plate 30 can also in one piece with the cap 29 by means of a film hinge 31 be connected. In this case, it is installed after the cap pivoted over the coil space and sealed.

The inventive manufacture of a coil former 1 for the relay described above is in the arrangement according to FIG 6 shown schematically. A die 100 with two Mold halves 101 and 102 have a mold cavity for the coil former 1, which in the form with the coil tube 11 and the flanges 12 and 13 is formed. Before injecting of the thermoplastic material in the mold become the fixed contact carrier 3 and 4, the invisible contact spring connector pin 5 and the coil pins 9 and 10, respectively as a wire section with the length X of corresponding semi-finished wires 103, 104, 105 (not visible) or 109 and 110 deducted from corresponding supply rolls 111 and into the Form advanced. The feed takes place via clamping jaws 112 and 113, which are opposite to each other according to the arrows 114 and 115 are moved perpendicular to the longitudinal direction of the wire, to clamp the wires and in the direction of the double arrow 116 to advance the dimension X. In the example shown the wires are clamped through the jaws during injection molding 112 and 113 still held and only after Spraying process separated. The separation is done by a Separating tool 117, which together with the jaws 112 and 113 is moved in the direction of arrow 119 and the Shears wires on the outside of the molded part 102. After that becomes the clamping of the jaws 112 and 113 on the wires loosened, and the jaws are in again by the dimension X Figure 6 moved right to position 112 'and 113' again clamp the wires and use a new section to advance the length X into the form. But it would be too conceivable to cut the wires before injection molding; in In this case, however, they would have to be shaped differently be fixed. In the example shown in FIG. 6, too the core 16 is injected into the bobbin. The form 100 in this case it has corresponding recordings for positioning of the core. The cylindrical end portion 19 is used for Centering in the injection mold; at the other end is the Pole plate 17 sealed in the injection mold in a suitable manner.

In the further manufacturing process, the finished coil former 1 removed from the injection mold; the mold opening direction is indicated by arrow 120. Then be on the fixed contact carrier 3 and 4 the fixed contacts 6 and 7 soldered, as shown in Figures 7 and 8. The one Semi-finished strip of contact pieces (fixed contacts 6 and 7) to form the normally closed and normally open counter contacts are in Recesses of an inner electrode 121 held, for example by negative pressure via a channel, not shown, inside the inner electrode 121. With the electrode 121 the two fixed contacts 6 and 7 between the two fixed contact carriers 3 and 4 pushed, which with the distance dimension d in the previously injected into the bobbin were. The two fixed contacts 6 and 7 are on the outside 6a or 7a each with a brazing layer (e.g. Silphos) Mistake. With this solder layer, the width dimension exceeds d1 of the inner electrode with the two fixed contacts according to Figure 7 somewhat the internal dimension d between the two fixed contact carriers 3 and 4. These fixed contact carriers are therefore at Insert the inner electrode 121 with the fixed contacts somewhat widened. Then, according to FIG. 8, two from the outside Outer electrodes 122 and 123 in the direction of the arrow shown opposite to each other against the fixed contact carrier 3 and 4 pressed. With that from a welding power source 124 between the inner electrode and the two outer electrodes Welding current becomes the solder layer on the surfaces 6a and 7a of the two fixed contacts 6 and 7 liquefied. There will be so much Lot displaces that the two fixed contact carriers 3 and 4 return to their previous position with the distance d and the contact distance between the two fixed contacts takes a predetermined measure. This is done the calibration of the contact distance.

The coil is wound in the usual way, with the winding ends be connected to the pins 9 and 10. Since the coil pins 9 and 10 are preferably square Have cross-section, the winding ends stick when Wrapping up better. They are preferably followed by a flux-free connection process, such as TIG welding, connected to the connector pins.

The magnet system is completed by pressing on and notching the L-shaped soft magnetic yoke 20 the protruding core end 19 in the region of the flange 13. Der Armature 22 with the contact spring 23 is used, and the Contact spring is with its mounting portion 23b on the Yoke riveted or resistance or laser welded as well contacted with its connecting portion 23c on the pin 5. After putting on the housing cap 29 and inserting it the bottom plate 30, which is only the winding space of the bobbin covers the relay with a sealing compound the circuit board side sealed. The connector pins, namely the fixed contact carrier 3, 4, the contact spring connector pin 5 and the coil pins 9 and 10, must not be guided through this base plate 30, so that no Particle abrasion occurs. Step in the manufacture of the relay no joining processes in the metallic relay parts with excess in the thermoplastic injection molded part of the Coil body 1 are added so that no scraped or abraded plastic particles occur on the electrical Contacts of the relay could interfere. The usual one complex assembly of the five connection parts for the coil and the load circuit is done in a single inexpensive Step in the injection mold with the least possible use of material, namely through the use of waste-free Semi-finished wires.

Claims (10)

1. Process for manufacturing a relay, which comprises a reel body with a reel tube, two reel flanges and a coil, a core with an L-shaped yoke, an armature connected to a spring contact as well as a connection pin for the spring contact and at least one first fixed contact carrier with a fixed contact, consisting of the following steps:

   a) the spring contact-connection pin (5), the at least one fixed contact carrier (3, 4) and the reel connection pins (9, 10) are fed and fixed into an injection moulding form (100) as respective sections of a semi-finished wire product;

   b) due to the injection of synthetic material into the injection moulding form (100), the reel body (1) is formed in such a way that in its first reel flange (12) a switch space (14) is created, whereby the at least one fixed contact carrier (3, 4) is embedded in the first reel flange (12) in the region of the switch space, and the spring contact-connection pin is also embedded in one of the flanges;

   c) the wire sections are separated from their respective semi-finished products (103, 104, 109, 110) before or after the injection process;

   d) on the at least one fixed contact carrier (3, 4) a fixed contact (6, 7) is welded or hard-soldered;

   e) the reel body (1) is foreseen with the coil (2), the core (16) and the yoke (20) in such a manner that a free yoke end forms a bearing edge (21) for the armature (22);

   f) the plate-shaped armature (22) is supported on the bearing edge (21) in such a manner that the spring contact (23) encloses the bearing point with a section offset at a right angle (23b) and is positioned opposite the at least one fixed contact (3, 4) with its contact-making free end (23a), and

   g) a connection section (23c) of the spring contact (23) is connected to the spring contact-connection pin (5).
2. Process according to claim 1, whereby a further fixed contact carrier (3, 4) is embedded alongside the first one in the reel body (1) and foreseen with a fixed contact (6, 7).
3. Process according to claim 2, whereby the two fixed contacts (6, 7) are fastened by means of an electric welding or soldering device (121, 122, 123, 124), an inner electrode (121) being arranged between the two fixed contacts, and two outer electrodes (122, 123) are positioned against the two fixed contact carriers (3, 4), so that the thickness of the inner electrode corresponds to the prescribed distance between the two fixed contacts (6, 7).
4. Process according to claim 3, whereby the fixed contacts (6, 7) are foreseen with a hard solder layer and through the melting and restabilisation of the hard solder layer the contact distance between the two fixed contacts (6, 7) is calibrated.
5. Process according to one of claims 1 to 4, whereby at least for the fixed contact carriers (3, 4) a wire (103, 104) with a square cross section is used.
6. Process according to one of claims 1 to 5, whereby the part of the wire sections which is to be embedded into the reel body (1) is foreseen with notches.
7. Process according to one of claims 1 to 6, whereby each fixed contact (6, 7) is in each case separated from a contact strip-semi-finished product and fastened to the corresponding fixed contact carrier (3, 4).
8. Process according to one of claims 1 to 7, whereby the spring contact-connection pin (5) is embedded in the first reel flange opposite the fixed contact carrier or carriers and the spring contact (23) is fastened to the yoke with a fastening section (23b) which is offset at a right angle over the bearing point of the armature (22), while a connection section (23c) folded over the fastening section (23b) is connected to the connection pin (5).
9. Process according to one of claims 1 to 8, whereby the core (16) is embedded in the reel body (1) during the forming of the latter.
10. Process according to one of claims 1 to 8, whereby the core is inserted in an axial recess of the reel body (1) and guarded against longitudinal displacement by means of embossed projections (16a).

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