EP1026717B1 - Relay with an L-shaped yoke and an armature that pivots on the edge of an arm of said yoke - Google Patents

Description

The invention relates to a relay of the type described in the preamble of claim 1.

A relay of this type is known from Belgian Patent No. 677,360.

This known relay has the disadvantage of not providing means for preventing the phenomenon of vibration and transfer of the pivot axis of the mobile armature due to the inertia of the latter at the end of the return movement of the frame in its removed position.

The object of the invention is to propose a relay of the type defined in the preamble of claim 1, which overcomes this drawback.

To achieve this goal, the relay according to the invention comprises the characteristics which are set forth in the characterizing part of claim 1.

Other features of the invention are the objects of the dependent claims.

• La figure 1 est une vue en perspective d'un relais selon la présente invention.
• La figure 2 est une vue, avec arrachement et à plus grande échelle, en direction de la flèche II de la figure 1, l'armature occupant sa position de repos.
• La figure 3 est une vue similaire à la figure 2, à l'échelle réduite, mais montrant l'armature dans sa position de travail.
• La figure 4 est une vue en perspective simplifiée montrant la culasse et les plaquettes d'antirémanent du relais selon l'invention à l'état de travail du relais, l'armature étant transparente pour illustrer la configuration du flux magnétique à l'intérieur du relais à l'état excité.
• La figure 5 est une vue de dessus de la figure 4, avec représentation également de la palette de l'armature mobile du relais.
• La figure 6 est une vue en perspective de l'armature mobile du relais selon l'invention, et des plaquettes d'antirémanent montées sur la palette.
• Les figure 7a et 7b sont respectivement des vues latérale et frontale d'une plaquette d'antirémanent à l'état de détente.
• Les figures 8a et 8b illustrent schématiquement respectivement le circuit d'alimentation des bobines du relais selon l'invention et la courbe caractéristique du courant d'alimentation en fonction du temps t.
• La figure 9 est une vue en perspective de la face arrière de l'armature du relais selon l'invention.
• La figure 10 illustrent le réglage des équerres de l'armature du relais selon l'invention pour un contact de travail et de repos.
• La figure 11 est une vue en coupe le long de la ligne XI-XI de la figure 1, du capot du relais selon l'invention.
• La figure 12 est une vue de dessus de la plaquette perforée du capot selon l'invention.

The invention will be better understood and other objects, features, details and advantages thereof will appear more clearly in the explanatory description which follows, with reference to the appended diagrammatic drawings given solely by way of example, illustrating a method of embodiment of the invention and in which:

• Figure 1 is a perspective view of a relay according to the present invention.
• Figure 2 is a view, cut away and on a larger scale, in the direction of the arrow II of Figure 1, the armature occupying its rest position.
• Figure 3 is a view similar to Figure 2, on a reduced scale, but showing the frame in its working position.
• FIG. 4 is a simplified perspective view showing the yoke and the antiremanent plates of the relay according to the invention in the working state of the relay, the armature being transparent to illustrate the configuration of the magnetic flux inside the relay in the excited state.
• Figure 5 is a top view of Figure 4, with representation also of the pallet of the mobile armature of the relay.
• Figure 6 is a perspective view of the mobile armature of the relay according to the invention, and antiremanent plates mounted on the pallet.
• FIGS. 7a and 7b are respectively lateral and front views of an antiremandent plate in the relaxed state.
• FIGS. 8a and 8b schematically illustrate respectively the supply circuit of the coils of the relay according to the invention and the characteristic curve of the supply current as a function of time t.
• Figure 9 is a perspective view of the rear face of the relay frame according to the invention.
• Figure 10 illustrate the setting of the brackets of the relay frame according to the invention for a working contact and rest.
• Figure 11 is a sectional view along the line XI-XI of Figure 1, the relay cover according to the invention.
• Figure 12 is a top view of the perforated plate of the hood according to the invention.

As an example of the implementation of the invention, an electromagnetic relay with a fast response and six contacts, as represented in FIG. 1, will be described below.

This relay enclosed in a transparent plastic cover 1 essentially comprises a yoke 2 in the shape of an L of which one leg 3 carries two cores 6, as can be clearly seen in FIG. 4 each carrying a coil 7, and a mobile armature 9 pivotally mounted around the end 10 of the other leg 11 of the yoke 2, between a rest position spaced from the free end faces 12 of the cores 6 and a working position in which the armature is applied against these front faces, with the interposition of antiremandent expansion plates 13 of an elastically deformable material, an insulating base 15 supporting the two terminals 16 and 17 for connection to the external supply voltage source of the relay and a device 19 of electrical contacts configured to be actuated by the movable armature 9.

The two coils 7 are connected in series, necessarily connected by their winding outputs. This assembly aims to create two main gaps of opposite polarities in series by the mobile armature common. The addition of a common yoke creates additional flow flow that optimizes performance over the single coil relay.

The movable armature 9 comprises a pallet portion 21 and three brackets 22a, 22b and 22c which have the shape of an L whose branch is intended to bear against the pallet 21 and can be secured thereto by a fixing screw 24 while the other end is formed by two arms 25 each carrying at its free end an insulating actuating pin 26 of an electrical contact of the device 19 and stop 27. Each pin is overmolded on the end of the arm and has the shape of a small cylinder extending on either side of the arm and has upper 27 and lower 26 portions respectively forming the abutment and actuating member of the associated electrical contact.

To allow adjustment of the position of the brackets in the direction perpendicular to the pivot axis of the pallet, the passage hole of the fastening screw 24 is formed by an oblong hole extending in the direction of adjustment. Thus a bracket 22a, b, c can be used for actuating a normally open or normally closed contact according to its more or less lowered position on the pallet 21. Between the fastening screw heads 24 and the brackets is interposed a blocking element 30, at least one of which is configured as a play-catch and vibration damping tab 31, as will be explained below. One end of this tongue is traversed by the fixing screw 24 while the free end 32 is pierced with a hole 33 for immobilizing the bracket during adjustment. The tongue is made of a material having a modulus of elasticity low enough to conform to the first closure of the pallet while taking support on a rear abutment face 33 of the base, as can be seen in FIG. 2. It then channels the vibrations generated by the moving armature when the relay is released, towards the thermoplastic base 15.

The pallet 21 comprises, at its lower edge, articulation means on the end 10 of the breech leg 11. As can be seen in particular in FIG. 6, these articulation means comprise at each bracket 22a , b, c at the top of a projection 35 a short rib 36 which extends parallel to the end of the breech leg and, on either side of this rib 36, at a distance from above the latter, which is slightly greater than the thickness of this end 10, lugs 37. Above the level of these lugs 38 is recognized at the end of the fixing screw 24. The pallet 21 and so the movable armature as a whole are mounted on the end 10 of the breech leg 11 by engagement of this end between the ribs 36 and the lugs 37.

The mobile armature 9 further comprises the two plates forming antiremanents 13, which are made of an elastically deformable material and each have a substantially rectangular shape being folded at a predetermined angle α along a fold line 40 which extends parallel to the axis of pivoting of the pallet 21 and at the end 10 of the cylinder head 11, the lower part of each plate 13 has two holes 41 of a diameter slightly greater than that of the pins 37 and a hole 42 with a diameter slightly greater than the end 38 of the fixing screw. The holes are arranged so that the plate 13 can be mounted on the inner face 43 of the pallet being solely retained by the lugs 37 passing through the holes 41 and 42. Each plate is dimensioned so that its lower and upper edges are respectively slightly above the rib 36 and below the upper edge of the pallet, the width corresponding to that of the adjusting brackets 22. It is also noted that the fold line 40 passes through the diameter of the hole 38.

An anti-remanent plate of relaxation and damping 13 is associated with each core 6 but is disposed eccentrically laterally outwardly. Thus, when the pallet is drawn against the front faces 12 of its core when the relay is energized, the portion between the pallet 13 and the front face 12 of the cores is flattened while the free lateral part tends to retain its original arched shape. , as can be seen clearly in FIGS. 4 and 5. The modulus of elasticity of the parts 13 is adapted to the amperes for maintaining the relay and to the main air gap, that is to say at the angle β of pivoting of the pallet between its rest and work positions.

The insulating base 15 on which is fixed the free bolt branch 11 consists of three modules 44a, 44b, 44c selectively removable.

Each base module has a pair of electrical contacts, which can be normally closed (normally closed) or normally open (work contact) contacts. Each contact comprises a movable blade 46 which is held fixed at one end 47 in the base 44 and carries at its other end a movable contact element 48 or 48 'intended to cooperate with a fixed contact element 49, 49' depending on whether it is a contact of rest or work. The external connection terminals of the movable contacts 48, 48 'and fixed 49, 49 'are respectively indicated at 51 and 52, 52'.

The excitation device of the fast response relay according to the invention comprises, in accordance with FIG. 8a, connected in series with the two coils 7 which are polarized in an inverse manner, a series connection of a diode D1 and a mounting in parallel of a resistor R1 and a capacitor C1. In Figure 1, the resistor R1 is divided into two resistors R1 'connected in series on a printed circuit board 54, the capacitor C1 being below the plate.

The device for generating excitation current produces, as a function of time, a current i as represented in FIG. 8b, which comprises a brief first phase in which the coils are supercharged by the flow of a current of an intensity high, because of the capacitor C1 in parallel with the resistor R1 and a second phase of flow of a lower current. The high current of the first phase ensures the rapid excitation of the relay while the current of the second phase is the current of maintaining the relay.

The hood 1 of parallelepipedal general shape is made of thermoplastic material. The upper wall of the hood is recessed and comprises a plate 56 of epoxy glass whose inner face 57 is covered with a copper layer in the manner of a printed circuit. The plate 56 is pierced with a large number of holes 58 of small diameters which are arranged in a pattern of rows and columns at a relatively small pitch. These holes 58 constitute ventilation holes and degassing, as is symbolized by small arrows. By way of example, the holes could be 0.9 mm at a pitch of 2.54 mm. Reference Numbers 59 to 61 refer to respectively the injection core, stiffeners and four vents. These chimney-shaped vents are at the base of the hood and are formed by grooves in the inner wall face.

The wafer 56 thus perforated could be replaced by a metal strip obtained by electrodeposition or wire mesh. The electroplating could be made of nickel / cobalt with microbeads with a diameter of, for example, 3 to 5 μm and a pitch of 50 μm.

The inner face of the perforated plate 56 constitutes the place where the condensation of the nitric acid vapors produced in the presence of moisture arches between the contact elements with high charge and which condense in an air confined to the inside of the hood on the coldest surfaces. These surfaces, in the known relays, are those contacts with low load that are practically not heated, or by the micro-arcs they generate nor by the coil.

In the relay according to the invention, the perforated plate 56 in the upper wall of the cover behaves like a radiator with respect to the external environment. The plate 56 constitutes an aerator, the hot air escaping through the holes of the plate and the four vents at the base of the hood allow the call for fresh air. Depending on the diameter of the holes, the perforated plate may be impermeable.

On the other hand, it is necessary, inside the relay, a degassing of plastics, slow but continuous, which can be accelerated by the heating of the coil. The same process of degradation with possible polymerization of friction polymers occurs under the action of the mechanical beats of the movable blades and in the absence of sufficient arcs on the low level contacts to destroy such surface films.

The gases caused by the degassing of plastics can be evacuated through the holes or micro-holes which, in the case of a nickel / cobalt plate with a diameter of 3 to 5 μm, are still 30 times greater than the molecules unwanted gases.

The general operation of the relay according to the invention and certain specific fundamental operating characteristics of the relay according to the invention will be described below briefly.

The rapid excitation of the relay, that is to say the transition from the state of rest to the working state for example in a time as short as 6 msec, rebounds included, is due to the capacitor C1 which runs The resistance R1 is circulated at the beginning of the process and thus creates the steep rise slope of the current i seen in FIG. 8b. Indeed, the coils are supercharged for a very short time, namely the charging current of the excitation capacitor. The instantaneous consumption of the relays is doubled during this time, then stabilizes at its nominal value determined by the series resistor R1 for maintaining the relay at work. The voltage pulse thus obtained is necessary to excite the relay, that is to say ensure the transition from the state of rest to the working state. The excitation of the coils causes the pivoting of the pallet which is attracted by the cores traversed by induction fluxes of opposite direction. The arms 25 secured to the pallet 21 will then, through the insulating pins 26 drive the movable blades 46 to cause the opening of the contacts at rest, then the closing of the working contact. pinches between the pallet 21 and the cylinder head 2 and placed in front of each core 6, the two antiremannent plates and detent 13 serve as dampers. They avoid the pallet 21 all risks of rebounds to percussion and choke the vibrations.

At the release of the relay, that is to say the transition from the working state to the idle state, when the control voltage is cut off, the forces of the six movable working and resting blades 46, to which the forces of the two anti-remanent expansion plates 13, which are elastically deformed, ensure the opening of the working contacts by the return of the mobile armature. In the continuity of its displacement are then established closure of the contacts at rest, that is to say, normally closed. At this time the action of the movable blades of the rest contacts ceases, as well as the forces of the antiremannous plates 13 now relaxed. The displacement of the movable armature, it persists being maintained by the movable blades 46 of the working contacts until the insulating pins 27 of the arms 25 corresponding to the movable blades of the rest contacts abut on the underside of the branch of the cylinder head 11, which thus constitutes a common reference. It is therefore the height of these insulating pins of the only movable blades with rest contact, which defines by the construction a constant clearance h between the actuating portion of the pin 26 and the rest contact blade 46, as it is see Figure 2. The interval of the height h is called resting accompaniment and is a reserve of wear. The action of the forces of the mobile working blades persists on the moving armature and defines the opening angle β of the pallet.

However, the return movement of the moving armature is not completed. We must still absorb the energy kinetics stored. The catch-up tab 31 absorbs a part of it. By inertia, the moving armature mass leaves the end 10 of the bolt branch 11. The axis of rotation is transferred from the stamping elements of the pallet, that is to say the hinge rib 36 and lugs 37 to pins 27 of the rest contacts. Following the return torques of the play catch tab 31 and the movable working blades 46, the pallet bounces and finds its pivot axis and its starting angle during this reverse pivoting. The rebound is stifled by the two relaxed antiremannents 13 and the moving blades of work.

It follows from the description of the structure of the fast response relay according to the invention and the description of the operating characteristics, which has just been made, that the relay according to the invention has many advantages. Thanks to the invention, the response time could be 6 msec to the action as to the release over a range of operating voltages ranging from 0.8 to 1.1 times the nominal voltage and in the entire range temperatures from -10 ° C to 55 ° C defined in the standards. This response time is virtually independent of the relay position and performance is maintained in all types of contact combinations. The separate contact combinations save 50% of the fixed and auxiliary contacts compared to the standard relay with changeover contacts. The volume of the relay, especially its base area is reduced. The relay has excellent resistance to shocks and vibrations. Regarding maintenance, a change of base to clean or replace the contacts in pairs is easy to perform and can be accomplished without adjustment. The service life and the stability are improved by the cover which, by its perforated plate, makes that the condensation of the harmful vapors takes place on the lower surface of this plate and thus preserving the resistances of the electrical contacts, and ensures the evacuation of heat and gases released by the plastics. Another advantage lies in the simplicity of the adjustment without sophisticated tools by spacers 63 of the accompaniments indicated in FIG. 10 and contact spacings. The simultaneity of the contacts is ensured thanks to the common and internal reference to the relay, which constitutes the bolt branch 11.

It is understood that the movable frame the insulating base and the hood contribute to provide these benefits.

As regards the mobile armature, it can be seen that the two antiremannents 13 have the quadruple function of acting as antiremans to stabilize the fall-back tension by their thickness, to serve as a shock absorber for action and relaxation, to fill the role of "launcher" of the pallet at release to overcome the inertia of the mobile armature and to define, by the double extra thickness at the ends of the pallet perfectly pivoting axis of the mobile armature. Antiremannents are significant because of their non-magnetic material, their thickness, their curve oriented towards the nucleus, their assembly in semi-freedom, that is to say without rigid fixation, their "flattening" with the action, circumscribed in the only diameter of the corresponding core and where the side "spared" keeps the "memory" elastic assembly. The modulus of elasticity of these antiremanents is adapted to ampèrestours maintenance and the main air gap, that is to say to the starting angle β of the pallet.

The catch-up tongues 31 of which at least one must be provided have the triple function of limiting the moving at rest of the movable armature, to play the role of washers whose hole 33 at the free end can immobilize them in rotation at the time of attachment of the adjustment brackets 22 on the pallet, which is essential to ensure the simultaneity of the contacts, and to comply with the first closure of the pallet by resting on the abutment of the base and then channeling the vibrations generated by the movable armature relaxation to the thermoplastic base. The modulus of elasticity of the pallet must be chosen rather low, correspondingly.

The adjustment brackets, rigid with the pair of overmoulded thermoplastic pins, are fundamental for damping, kinematics of contacts and combinations of contacts. They have the peculiarities of allowing a height adjustment in pairs of contacts, to accomplish the dual function of driving the movable blades and adjustment stop on a common plane formed by the cylinder head. The invention allows a blocking during the fixing of each bracket, which preserves the simultaneity of the contacts. The setting allows you to clear tolerance dispersions and all combinations of bracket-off contacts in a minimum non-overlap range. The brackets fix the constant opening angle of the pallet and define the work and rest accompaniments. They guarantee the distances between the fixed and mobile contacts, that is to say normally open and normally closed. They allow simple control of the relays terminated by the introduction of a pair of appropriate shims between the breech leg 11 and the pins 27 of all the contacts to ensure the rest and work accompaniments and the intergrains.

Regarding the base and the contact device, it is found that the movable blades belong to the base and it is the working blades that ensure the constant recall of the pallet, without the addition of a parasitic spring and its mobile armature game . The separate contact solution also saves 50% of the fixed contacts. This advantage is accompanied by the recovery of the corresponding accompaniments, thus a reduction of the angle β of movement of the pallet. Indeed, this angle is reduced to about half and the accompaniments and adjacent grain are reduced while maintaining the same maneuvering powers. This makes it possible to increase the force of the idle contacts by 40% and to reduce the stroke by 50%, which contributes to increasing the speed of the response of the relay according to the invention.

Claims (20)

1. Relay of the type comprising an L-shaped yoke (2), one branch (3) of which bears at least one core carrying a coil (7) which generates a magnetic flux when an electric excitation current passes through it, an armature (9) which is mounted on the end of the other branch of the yoke so as to pivot between a position in which said armature is applied to the front face of the core, with interposition of an anti-remanent element (13), and a resting position in which it is at a distance from said front face of the core, said armature advantageously bearing a plurality of arms (25) for operating movable strips (46) which are fixed at one end in a base (15), their other ends bearing movable contact elements (48, 48') designed to cooperate with fixed contact elements (49, 49'), and the anti-remanent element (13) taking the form of a plate made of a material which is elastically deformable upon application of the armature (2) to the front face (12) of the core (6) so as to form means for returning the armature (9) into its drawn-back position, said anti-remanent plate (13) being fixed at one end to the armature whilst its other end is at a distance from the armature level with the end of the armature opposite the pivoting end, characterized in that the yoke (2) is fixed on to the insulating base (15), and in that it has at least one tongue (31) for taking up play which is made of a non-magnetic material with low modulus of elasticity and is interposed between the movable armature (9) and the base (15), and in that the tongue (31) for taking up play together with the anti-remanent element (13) form means for damping and muffling vibrations occurring upon excitation and release of the relay.
2. Relay according to Claim 1, characterized in that the yoke (2) bears two parallel cores (6) which cooperate with a single movable armature (9) and of which the coils (7) are connected in series so that the free front faces (12) of the cores can form different magnetic poles.
3. Relay according to one of Claims 1 or 2, characterized in that the device for generating current for excitation of the relay includes means (C1) ensuring a brief response time to excitation and release of the relay by overfeeding of the relay for an initial period by means of a high current, followed by a lower current for maintaining the relay.
4. Relay according to Claim 3, characterized in that the device for generating the excitation current includes, in series with the coils (7), a parallel connection of a resistance (R1), for determining the rising current, and of a capacitor (C1).
5. Relay according to one of the preceding claims, its movable armature consisting of a portion forming a pivoting vane which cooperates with the cores, and a certain number of the aforementioned arms for controlling electric contacts of the relay, characterized in that the anti-remanent element (13), interposed between the free front face (12) of a core (6) and the vane (21), is formed by a plate which is folded along a fold line (40) extending parallel to the pivoting axis of the vane and is disposed on the inside face of the latter in such a way that the portion located between the core's front face (12) and the vane is bent towards said face when the vane occupies its drawn-back position, whilst the portion below the fold line (40) is retained on the inside face of the vane.
6. Relay according to Claim 5, characterized in that the portion located below the fold line (40) is retained on the inside face of the vane by retaining means which permit a certain play perpendicular to said face.
7. Relay according to Claim 6, characterized in that the retaining means are formed by elements (37) projecting from the inside face of the vane (21) and holes (41) drilled through the plate, the projecting elements passing through said holes, with a certain play.
8. Relay according to Claim 7, characterized in that each anti-remanent plate (13) is disposed between the corresponding core (6) and the pivoting vane (21) so as to be laterally off-centre towards the outside so that, upon application of the vane (21) to the front face (12) of the core (6), a lateral portion of the plate (13) remains substantially undeformed.
9. Relay according to Claim 8, characterized in that an arm (25) for electric-contact control forms one branch of an angle-iron (22) which is mounted so as to be displaceable perpendicular to the pivoting axis (10) of the vane (21) on the outside face of the latter and in that the tongue (31) for taking up play forms a means of locking the fixing screw (24) of the angle-iron on to the vane, one end of the tongue being passed through by the screw (24) whilst the other free end (32) rests on the base and is provided with a drilled hole (33) for immobilizing the angle-iron upon adjustment.
10. Relay according to one of Claims 1 to 9, characterized in that a control arm (25) bears at its free end a stud-bolt comprising a control stud portion (26) and an abutment stud portion (27) which rests underneath the yoke when the arm is controlling a resting contact.
11. Relay according to Claim 10, characterized in that each arm (25) causes pivoting of a movable strip (46) carrying a movable contact element (48, 48') which cooperates with a fixed contact element (49, 49') mounted in the base (15).
12. Relay according to Claim 11, characterized in that the flexible strips (46) form means for returning the movable armature (2) into its drawn-back resting position.
13. Relay according to one of the preceding claims, characterized in that it includes a cover (1), of which the upper wall is made in the form of a plate (56) which is permeable to air and to the gas produced by degassing of the plastic materials of the relay, and of which the inside face (57) forms a surface for condensation of the nitric acid vapours produced inside the cover in the presence of humidity by the electric arcs between the contact elements.
14. Relay according to Claim 13, characterized in that the plate (56) is formed by a perforated plate, the lower face of which is covered with a layer of copper in the manner of a printed circuit.
15. Relay according to Claim 14, characterized in that a perforation hole (58) has a maximum diameter of 0.9 mm and a pitch of 2.54 mm.
16. Relay according to Claim 13, characterized in that the aforementioned plate is made of a metal strip obtained by electrodeposition or is made of metal cloth.
17. Relay according to Claim 15, characterized in that the electrodeposition is carried out using a material such as nickel/cobalt, the holes having a diameter of several µm and a pitch of 50 µm.
18. Relay according to one of Claims 13 to 17, characterized in that the cover (1) has ventilation holes (63) at its base.
19. Relay according to one of Claims 1 to 18, characterized in that the tongue (31) for taking up play is fixed by one end to the armature at a point above the pivoting axis of the armature, whilst the other end of the armature rests on a stop (33) on the base at a point located below the pivoting axis.
20. Relay according to Claim 19, characterized in that the anti-remanent plate (13) is fixed at one end to the armature whilst its other end is a distance apart from the latter when the armature is in its drawn-back position and in that the end of the anti-remanent plate (13) which is a distance apart is disposed level with the free end of the armature away from the end pivot-mounted on the branch (11) of the yoke.

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