Patent Grant
7633363
The invention relates to a forcibly guided relay with an electromagnetic drive.
Forcibly guided relays are known in a multitude of embodiments. As a result of the constant development in the direction of miniaturisation of circuits, the developers of relays are under some pressure to provide relays with as small as possible dimensions. For the installation into a 17.5 mm standard housing of safety circuits for apparatus controls, e.g. the height of the relay may be 12 mm at the most. Furthermore, as the case may be, SMD-components should be able to be accommodated between the relay and the printed circuit board, onto which the relay is stuck. This miniaturisation causes the tolerance ranges in the inside of the relay to be reduced. This, amongst other things, leads to the fact that the distances between current-conducting parts in the inside of the relay are reduced, and therefore the creepage distances and sparking distances between these parts must be extended by way of intermediate constructions, that the dimensions of contact springs and the flash strengths of contact heads are reduced, and that the adjustment of the contact springs becomes more of a problem. Indeed, not only are the tolerances for the circuit paths low, but also the force conditions between the contact springs and the drive do not leave much of a tolerance margin.
It is therefore the object of the invention to suggest a relay, which has very small dimensions.
According to the invention, this object is achieved by the subject matter of claim 1.
A further object of the invention is to prepare a basis for being able to provide a relay series, said relays being equipped with 3, 4, 6 and, as the case may be, 8 contact pairs, which may be loaded in each case with at least 6, preferably 8 or even 10 Amps, whose heights project maximally by 12 mm beyond the connection pins, which are maximally 35 mm wide and 56 mm long, and which fulfil the Euro standard EN 50205 for forcibly guided relays. As many components as possible, in particular the contact pairs, are to be designed identically with the relays of this series. A further object is for the relays to be adjusted in a manner which is as simple as possible.
A forcibly guided relay according to the invention has a housing determining the outer dimensions, whose height is smaller than its width, and whose width is smaller than its length.
The relay comprises an electromagnetic drive filling the length or width of the relay, with a clapper-type contactor, which comprises a drive arm extending in the direction of the core. The drive arm at its free end cooperates with a drive cam. The relay furthermore comprises several contact pairs which are formed in each case by a contact spring and a fixed or spring-like counter-contact. The contact springs extend in the direction of the core, and with their drive ends are in forcibly guided engagement with the drive cam.
With this relay, the contact pair which is arranged directly next to the contactor, is a break-contact, whose contact spring in each position of the contactor, runs at least approximately parallel to the drive arm of the clapper-type contactor. In the activated position of the drive arm of the clapper-type contactor, which is spread away from the coil, a separating wall present between the clapper-type contactor and the break-contact, runs approximately parallel to the drive arm, at least in the region between the contact head of the break-contact and the drive cam.
The drive usefully comprises a coil with an elongate core of magnetic soft iron, and a winding present around the core. The winding has a diameter which practically fills the height of the housing.
The contact springs usefully comprise a foot and a free drive end, as well as a contact head between the foot and the drive end. They are each anchored in the housing with the foot at locations along a side of the housing lying perpendicular to the direction of the core, said locations being distanced to one another. They extend in the direction of the core and with their drive ends are in forcibly guided engagement with the drive cam.
The contact pins for the contact pairs and for the drive, project out of the housing perpendicular to a surface of the housing defined by width and length.
Such a forcibly guided relay in one embodiment comprises an electromagnetic drive filling the length of the relay, and six contact pairs, as well as the necessary contact pins for the six contact pairs and for the drive. The six contact pairs are in each case formed by a contact spring and a fixed counter-contact. The contact springs with the foot are anchored in the housing along the width of the housing at locations which are distanced to one another. The drive ends of the contact springs of three contact pairs arranged in a row are directed counter to the drive ends of the contact springs of three contact pairs arranged in a second row.
Other embodiments comprise an electromagnetic drive filling the width of the relay, and three or four contact pairs, as well as the necessary contact pins for the contact pairs and for the drive. With these embodiment examples, the contact pairs are only arranged in one row.
With such a relay, one may not only achieve very small dimensions, but also EN 50205 and a current-carrying capacity of 6 to 10 A, in particular one of 8 A, per contact pair. The height of the relay advantageously measures maximal 12 mm, preferably maximally 11 mm. The embodiment examples described in more detail by way of the Figures measure 10.5 mm. The diameter of the coil measures 8 to 10 mm, preferably 8.5 to 9.5 mm. The coil diameter with the embodiment examples measures approx. 9 mm.
The length of the two-row relay usefully measures maximally 56 mm, preferably maximally 54.5 mm, and the length of the coil at least 40 and at the most 46 mm, preferably at least 42, and at the most 44 mm. With the two-rowed embodiment example, the housing length measures 53.8 and the coil length 42.7 mm.
The coil is practically half as long with the relays with only one row of contact pairs. The outer dimensions in the direction of the coil, and the core and the coil length are 24.2 mm smaller than with a relay with two rows of contact pairs.
The coil is designed as long as possible, so that the height of the relay may be as small as possible. It has been found that a coil with the dimensions specified above has a relatively low power consumption of approx. 0.5 to 0.8 Watts (0.75 Watts with the embodiment example), with a maximal current conduction of the contacts of 6 to 10 Amps (with the embodiment example 8 A). One may actuate six contact springs (four make-contacts and two break-contacts) with this power. With the smaller relays, the reduced dimensions are likewise sufficient for a correspondingly reduced number of contact pairs, wherein the power consumption may only be slightly reduced.
So that the drive has the suitable characteristics, the core is manufactured of a high-grade material with a small coercive field strength of roughly 40 A/M. The winding space is maximally utilised. The housing and a core cladding consist of a liquid crystal polymer and have a wall thickness of maximal 0.7 mm, at least in the region of the drive. In particular, walls in the inside of the housing which are relevant to the dimensions of the relay, have a wall thickness of maximal 0.5 mm. The relay base is 0.7 mm thick in the region of the contacts. The core cladding has a wall thickness of 0.4 mm.
The width of the six-contact relay, or the length of the three-contact relay, measure preferably at the most 35 mm, particularly preferably at the most 34 mm. This just about permits the feet of the contact springs, or the pins of the contact springs formed at the feet, to be arranged at a minimal raster distance to one another in the direction of the width of the housing. This distance in each case measures between 7.3 and 7.7 mm, preferably between 7.4 and 7.6 mm, and 7.5 mm in the embodiment example. This distance ensures that the prescribed 5.5 mm distance between the connection locations in the printed circuit board in which the pins are soldered or inserted, may be adhered to. The four-contact relay is longer than the three-contact relay by such a raster distance.
Advantageously, the pins for the contact pairs are arranged in a rectangular raster. The pins at the feet of the contact pairings are arranged on the housing edge. With the six-contact relay, the pins of the fixed counter-contacts are arranged symmetrically to a middle axis running in the direction of the width of the housing. In the direction of the length of the housing, the latter have a raster distance of at least 12 and at the most 18 mm to one another. Preferably, the distance between the pins of the fixed counter-contacts is equally large as the distance between the pins of the counter-contact and the contacts springs of a contact, and this is also achieved.
With a single-row relay, the pins of the fixed counter-contacts are arranged at the same distance to the pins of the contact spring as with the two-row relay. They therefore lie about 10 mm or about 19 mm from the edge of the housing.
Usefully, the contact pair lying closest to the drive pair or both contact pairs lying closest to the drive are break-contacts. They open away from the drive. The other two to four contact pairs are make-contacts and close away from the drive. The fixed counter-contact of the break-contact may be aligned slightly rotated with respect to an alignment orthogonal to the housing, so that the contact head of the loaded contact spring, which cooperates with it, rests on in an almost parallel manner. Amongst others, this arrangement has the advantage that thanks to the arrangement of this rotated-away, fixed counter-contact adjacent to the drive, this rotating-away of the fixed counter-contact leads to the fact that the distance between the drive and the first contact pair may be reduced, since the space required by the drive arm of the clapper-type contactor, and the separating wall between this space and the break-contact, run roughly in the same inclination as the counter-contact of the break-contact. The closer the fixed counter-contact approaches towards the foot of the contact spring, the larger does this reduction become. The separating wall may run in the desired direction from its end at the drive cam side, to beyond the contact head of the counter-contact. This serves for shortening the dimension of the housing directed perpendicular to the direction of the core (width with the two-row, length with a single-row relay).
In order for the distances of the pins to be minimal, the contact springs of the two make-contact pairs situated closest to the drive, and the contact springs of the make-contact pairs adjacent to these, converge from their foot to their head. The sparking distances and creepage distances between adjacent contact pairs may be extended to the necessary lengths in the inside, by way of separating walls on the base part and cover part, and by way of further obstacles on the drive cam.
With the two-row relay, the contacts springs situated closest the drive are usefully arranged in a symmetrical manner. That contact spring which is arranged on the side of the contactor, runs at least approximately parallel to the drive arm of the clapper-type contactor, or even diverging from the foot to the contact head end. This serves the shortening of the width of the housing. This is at least the case when a separating wall between the clapper-type contactor and the contacts is directed approximately parallel to the maximally folded-out drive arm of the clapper-type contactor. The drive arm is folded out maximally when the clapper-type contactor is attracted by the magnet.
Generally, with such a relay, at least one of the extended contact springs is not aligned orthogonally to the housing. The deviation of an alignment of the relaxed contact spring orthogonally to the housing outer surfaces having the housing height is predefined by an alignment of a foot receiver for the foot of the contact spring, which is formed on the housing. The adjustment of the foot receiver, which is the adjustment of the direction of the slot in a block formed in the housing, in combination with the unbent, extended contact spring, permits a very inexpensive general adjustment of the contact pairs on the housing, and specifically before the assembly of the relay. The adjustment is effected on the casting mould of the housing.
In order to be able to optimise the drive force of the relay, the pressing force of the make-contacts and the length of the overtravel, the contact spring in the region of the free drive end has a smaller cross section than between the foot and the contact head, and this tapered drive end projecting beyond the contact head has a length of 4 to 7 mm. This length and the tapered cross section permit a springing of this drive end beyond a contact point. The drive end preferably has a length of 5 to 6 mm. An overtravel which this permits is for example 0.3 to 0.7 mm.
The invention thus rises beyond the perception that each contact spring of each relay needs to be adjusted after the assembly and suggests a solution, which permits such an adjustment after the assembly to be able to be done away with. It thus permits the tolerance regions of the contact springs, of the distances between the contact head, of the biases of the contact springs, of the overtravels, of the force equilibriums between the drive and the contact spring assembly etc., to be reduced, and thus permits the size of the relay to be minimised.
Such a relay in the known manner has a housing and at least one adjusted contact pair therein. The contact pair advantageously comprises at least one contact spring, which for anchoring in the housing is inserted with a foot in a slot, which is formed in a block in the housing. The contact spring is equipped with a contact head, which cooperates with a contact head of the counter-contact.
The relay is advantageously characterised in that the contact spring of an adjusted contact pair is formed extended in the relaxed condition. A contact spring which is formed extended in this document is to be understood in that a straight line from a contact head end up to a foot end of the contact spring may be arranged within the contact spring. Usefully, contact springs are plane-surfaced parts, without any form of bending or curvature, with the exception of the doubling of the thickness of the foot by way of a folding of the spring material at the foot end. A further exception may be a hook formation at the drive end of the contact spring, which is to prevent a broken contact spring from falling out of the drive cam. Such contact springs which are formed extended from their anchoring, up to the contact head or even beyond the contact head, may be manufactured with very low tolerances.
The relay is further advantageously characterised in that the direction of the slots is predefined in a manner such that in an idle condition of the relay, the contact head of the contact spring is arranged within a selected distance range to the contact head of the counter-contact, when the contact spring is part of a make-contact. The relay may comprise make-contacts or break-contacts and preferably has both. For this reason, with the relay alternatively or additionally with a break-contact, the direction of the slot is defined in a manner such that a pressing pressure of the contact head of the loaded contact spring, with which this contact head is pressed against the contact head of the counter-contact in the idle condition of the relay, lies within a selected pressure range. Thereby, what is essential with regard to the invention is that the adjustment of the contact springs is not effected by kneeing or bending, but the contact spring of an adjusted contact pair is extended in the relaxed condition, however the direction of the slot in which its foot is anchored, is adjusted. Such an adjustment may be carried out on the housing or on the cast mould of the housing. Since the injection moulded parts and the extended contact springs may be manufactured with very tight tolerances, an adjustment of the contact springs after the assembly of the relay is no longer necessary. For the manufacture of such a relay therefore, the direction of the slots is to be adjusted with the injection mould, before the relay goes into production. In exchange, the work of a later adjustment of the individual contact springs is largely done away with. Despite this however, it may make sense and be necessary to control the adjustment, and individual contact springs nevertheless may be adjusted afterwards, as the case may be. If it is also desired for none of the contact spring to have to be adjusted at a later stage, then a relay according to the invention merely comprises a single contact spring, which is adjusted according to the invention. Preferably all contact springs are adjusted in this manner.
The counter-contact is preferably a fixed contact and is not also a contact spring. A fixed counter-contact may be applied into the housing with very small tolerances. One however does not also rule out designing the counter-contact as a spring. Such a contact spring of a counter-contact is also designed extended in the relaxed condition. It is anchored in a slot in a block formed in the housing. In contrast to the first contact spring it presses against an abutment formed on the housing. The slot is aligned with respect to the abutment, in a manner such that the pressing force of the contact spring against the abutment lies within a selected pressure range.
The users of relays desire the pins of the contact pairs to be arranged in an orthogonal raster. This not only has aesthetic aspects, but also simplifies the adherence to sparking and creepage distances on a printed circuit board.
In order for the orthogonal alignment of a pin arrangement and the adjustment of the contact pairs to be able to be simultaneously achieved by way of the adaptation of the direction of the slot, where appropriate, the slot must be aligned with regard to the housing differing from an orthogonal alignment.
Thereby, one accepts the fact that the planes of the pins are not directed orthogonally, but only the axes of the pins are arranged in an orthogonal raster. The planes of the pins are usefully parallel to the plane of the extended contact spring. This is because the pin of the contact spring is advantageously designed as one piece with the contact spring. The single-piece design of the contact spring, and the pin of a piece of highly conductive spring material reduces the effort on assembly of the relay, reduces the tolerances with the contact spring, and ensures a first-class conductivity at the transition from the pin to the contact spring. The pin is usefully formed on the foot of the contact spring.
This deviation from the orthogonal alignment, as the case may be, may be a sign that the contact springs have been adjusted by the adaptation of the direction of the slot. This slot direction differing from the orthogonal alignment, may therefore considered as an independent invention, independently of whether the contacts springs have been adjusted after their installation by way of bending or not.
A transition between a contact region of the contact spring and the foot of the contact spring is advantageously designed extended, in order to avoid the deviations between the individual contacts springs occurring on bending.
With a method for adjusting the alignment of a contacts spring of a contact pair, which is anchored with a foot in a slot in a housing of a relay, one is to succeed in a distance between the contact heads of the contact pair lying within a selected distance range or a pressing force between the contact heads of the contact pair lying within a selected pressure range. With such a method, according to the invention, the direction of the slot is adjusted in an exact manner, and a contact spring designed in an extended manner is inserted into the adjusted slot. The block in which the slot is formed may be designed rotatable relative to the housing, for adjusting the slot. In this case, the adjustment of the direction of the slot includes a rotation of the block and the fixation of the block with respect to the housing in the adjusted direction. In order however for this adjustment to only have to be carried out once, it is preferable for the injection mould which defines the direction of the slot, to be adapted. Part moulds may be provided with the injection mould, which comprise the slots or the blocks with slots. Thus only these part moulds need to be adapted. Should a later delivery of contact springs for example have different parameters than an earlier delivery, then these part moulds are replaced by those which are adjusted for the new delivery of contact springs.
The slots thereby mostly fall out of an orthogonal alignment with respect to the housing and/or an orthogonal pin raster. Despite this, it may occur that a slot, despite this, is orthogonal to the housing, or the pin raster. The slot therefore as a rule, is aligned at an angle to the housing which differs by 0, 90, 180 and 270 degrees.
In order for the adjustment of the contact pairs to be able to be carried out by way of the direction of the slots, advantageously the precision of the contact springs must be checked before the insertion into the slot. With this, one checks whether the adjustment to the contact pins to be inserted is correct, or whether they need to be adapted.
In order for the contacts pins at least of one delivery to be identical within very tight tolerances, the foot at the contact pin is advantageously formed by folding the spring material. Folding, which is to say bending by 180 degrees, may be carried out with a very constant result, whereas a bending by a lesser angle, be it obtuse or oblique, leads to larger scatters. With folding, the extended formation of the contact springs remains untouched. A transition between the foot and a spring region of the contact spring should be designed in an extended manner, so that the contact spring may be manufactured with a high precision.
The relay 11 represented in
The relay 11 furthermore has an electromagnetic drive 15 with a coil 17, a yoke 19, a clapper-type contactor 21 and a core 23 represent dashed. It further comprises a drive cam 27 cooperating with the drive arm 25 of the clapper-type contactor 21.
The coils 17 are wound in an as space-filling as possible manner. Depending on the desired coil voltage, the winding number and the wire diameter, and thus the coil resistance may be adapted. Thereby however, the AW-number (Ampere*windings), which corresponds to the coil force, remains practically the same. The AW-number with the present embodiment is at least 310 AW. Depending on the wire thickness, the AW-number may exceed this 310 AW, since the coil is filled. An adequate force of the coil to actuate the six contact pairs 13 results with a coil ratio of 4.6-5 to 1, in particular 4.7-4.8 to 1, and with an contactor transmission ratio of 1 to 3.5-3.7, in particular of 1 to 3.6. The subsequent list shows a small selection of possible coil designs:
Each contact pair 13 comprises a contact spring 29 and a counter-contact 31. The contact springs 29 are anchored in a housing 35 with a foot 33, in which housing 35 the drive 15 is also accommodated. For anchoring the foot 33, a block 37 is formed in the housing 35 for each foot, and in each case a slot 39 in the block 37.
The counter-contacts 31 and the contact springs 29 are in each case equipped with a pin 41 (see
The raster distances between the pins of the contact pairs 13 are in each case 7.5 mm in the direction of the width of the housing, and in each case 15.8 mm in the direction of the length of the housing 35. The connection pins of the drive are in the two corners of the housing base 43 which are not equipped with the foot pins of the contact springs, and at a distance of 15.5 mm to the next pin of the contact pairs 13.
The contact springs 29, as represented in
The counter-contacts 31 are stationary contact parts which are fastened in the housing in an exactly defined position. The counter-contacts 31 are parts punched from relatively thick sheet-metal, on which a pin 41 is formed as one piece (
The relay represented in
The following parts are therefore represented in
the base part 51 with a base 43 and a division into chambers for the contact parts and the drive, which is formed by walls 63 as well as with blocks 37, 53 for the anchoring of the contacts 29, 31 of the contact pairs 13;
the drive 15 applied into the base part 51, of which the coil 17, the yoke 19 and the clapper-type contactor 21 may be recognised;
four break-contact pairs 13 each with a relaxed, extended contact spring 29 and a fixed counter-contact 31;
two break-contact pairs 13 each with a loaded contact spring 29 and a fixed counter-contact 31;
a drive cam 27 which is in abutment with the drive arm 25 of the clapper-type contactor 25, and in which the drive ends of the contact springs 29 are accommodated. An individual chamber is formed for each contact spring in the drive cam.
The drive cam 27 is furthermore provided with wings 28. The wings 28 extend the creepage and above all the sparking distances between the adjacent contact pairs 13.
The relay 11 according to
The cover 59 indicated in
The relay according to the invention, as in
The dimensions of the relay are as follows:
The dimension perpendicular to the core of the coil is composed of 7.5 mm between in each case two contact pairs of a row, and 18.5 mm for the drive, the housing and the distance between the drive and the break-contact. 16.9 mm is required from the one outer side of the relay which runs along the drive, up to the first pin (of the break-contact). 1.6 mm is yet required from the last pin to the opposite outer side.
In the other direction, the pins of one contact pair have a distance of 15.8 mm, the pin of the contact spring up to the close edge of the relay 3.1 mm. The pin of the fixed contact has a distance to the opposite edge of 10.5 mm. With a two-row relay, the pins of the fixed contacts of the two rows have a distance of 15.8 mm to one another.
These dimensions include the cover, which on the five sides which it covers, is in each case 0.6 mm.
With the single-row relay, the coil data may be specified for example as follows. Further designs of the coils are of course possible. The coil is 18.5 mm long, has a diameter of 9 mm and with four contact pairs, one strives for an AW-number of 200 or more.
Relay with four contact pairs
| Number | Date | Country | Kind |
|---|---|---|---|
| 00426/06 | Mar 2006 | CH | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 4405911 | Hasegawa et al. | Sep 1983 | A |
| 5053756 | Wehrle et al. | Oct 1991 | A |
| 5111171 | von Bonin et al. | May 1992 | A |
| 5568108 | Kirsch | Oct 1996 | A |
| 5831502 | Kirsch | Nov 1998 | A |
| 6034582 | Fausch | Mar 2000 | A |
| 6081177 | Fausch | Jun 2000 | A |
| 6559744 | Kirsch | May 2003 | B1 |
| 6906604 | Mader et al. | Jun 2005 | B1 |
| 20010045878 | Fausch | Nov 2001 | A1 |
| 20020050885 | Gruner | May 2002 | A1 |
| 20030085784 | Weber | May 2003 | A1 |
| 20050200439 | Kawahara et al. | Sep 2005 | A1 |
| Number | Date | Country |
|---|---|---|
| 1 143 474 | Oct 2001 | EP |
| 1 308 976 | May 2003 | EP |
| 2 423 855 | Nov 1979 | FR |
| Number | Date | Country | |
|---|---|---|---|
| 20070216502 A1 | Sep 2007 | US |
