EP2704174B1 - Relay with modified force-distance characteristic curve - Google Patents

Description

The invention relates to a relay with modified force-displacement characteristic according to the preamble of claim 1. Such a relay is, for example, with the subject of EP 1 121 700 B2 known. This relay discloses an adaptation of the force-displacement characteristic to the drive characteristic such that the actuator operates in two different levels of actuation, that is, the actuator for the normally closed contacts is in a different horizontal plane than the actuator for the normally open contacts. When the actuator is moved, the normally closed contact opens first, before the normally-closed contact closes. This means that the required by the actuation of the closer power must be applied wegverzögert from the drive. This achieves a modification of the force-displacement characteristic of the contact set. This results in the advantage that the drive characteristic and the contact set characteristic are adapted to each other.

From the cited document shows that in the idle state of the actuator, for example, at a certain point s1 (or right of it) FIG. 7 this document is located, the point s1 is dependent on contact erosion. When tightening the armature, the actuator moves to the left, the force m of the magnet system initially increases only slowly. In this area up to a point s2 but also to overcome the Öffnerkraft (on the active contact spring or the spring arm adapted to this) necessary actuation force due to the large leverage is still relatively low.

From a point s2 to s3 results from the addition of active work contact springs, a stronger rising spring force by a in In this area also stronger increasing magnetic force m of the drive system is overcome. From a point s3 to the mutual stop of the contacts, both the spring force f and the magnetic force rise sharply. This is the range of the overstroke that extends to point s4. The mentioned representations refer to the FIG. 7 of the EP 1 121 700 B2 and on the FIG. 8 the present invention, in which the FIG. 7 the cited document was drawn as prior art.

Subject of this document is accordingly that the force-displacement characteristic or - as hereinafter referred to better as a contact set characteristic in the following description - to be adapted to the non-constant working travel (drive characteristic) of the magnet system.

It should be avoided, in particular, that the contact set characteristic curve intersects with the drive characteristic of the magnet system, because in this way an unstable actuation path is provided and a smooth, jerk-free and continuous actuation of the contact set is no longer guaranteed.

The cited document solves this problem of modifying or modeling the contact set characteristic compared to a constant constant drive characteristic in that the actuator acts on the contact set in two different levels.

In this document, the contact application points of the actuator are assigned to the associated contacts and remain fixed during the actuation path in a fixed, unchangeable distance from each other. Thus, the gear ratio is fixed. Hereby meant the distance of the clamping point of the respective spring to the plane of actuation of this spring. A change in the levels of the force application points during the operation does not take place. The height difference of the two levels of actuation, which mentioned document EP1 121 700 B2 defined does not change.

Characteristic of the EP1 121 700 B2 is that the actuation of the normally closed contacts and the normally open contacts is assigned in each case only a single actuation plane of the actuator, so that the respective actuation level, a contact (opener or closer) is assigned. The one distance between the operating plane 1 and the clamping point of the spring is associated with the closer, and the other distance between the operating plane 2 and the clamping point of the spring is associated with the opener.

In the two publications DE 20 2004 011 488 U1 and EP 1 681 699 A1 is an electromechanical relay described according to the preamble of claim 1, wherein, however, does not take place during the displacement of the actuator, a displacement of the force application point in the direction of the longitudinal extension of the actuated contact spring. Consequently, it is not possible to adapt the force-displacement characteristic of the contact spring to the non-constant working travel (drive characteristic) of the magnet system.
The invention is therefore the object of developing a relay with modified force-displacement curve of the type mentioned so that a better and also changeable adaptation of the contact set characteristic to a drive characteristic of a drive system of a relay is possible.

To solve the problem, the invention is characterized by the technical teaching of claim 1.

A feature of the invention is that during the stroke of the actuator, a transition of the actuation of the active contact springs from a first operating level to a second operating level takes place. Due to the design of the surface between the two levels of actuation of the actuator, the discontinuous (sudden) transition from the level 1 to the level 2 can be fixed.

With the given technical teaching also results in the advantage that a steady transition from one operating level to another level of actuation can be achieved because the invention provides that each of the active springs associated cams of the actuator each have an actuating surface in the direction of actuation of Actuator not only form an angle to the direction of movement of the actuator, but are additionally provided with a curvature.

This ensures that the actuator rests with an obliquely to the point of application of the spring to be actuated actuating surface on the contact spring to be actuated, so with progressive actuating travel of the actuator first, the spring to be actuated at its upper end (level 1) - far away from her Einspannungspunkt - is detected and actuated, and that during this actuation path of the force application point due to the inclined actuating surface down - towards the clamping point of the spring (level 2) - wanders.

With increasing deflection of the actuated spring of the actuator engages with its inclined cam now further down to the spring to be actuated. Thus, the force application point is displaced from an upper point (level 1) to a lower point (level 2) during the movement of the actuator and during the attack on the active spring to be actuated, whereby this displacement of the force application point preferably takes place continuously.

The transition from level 1 to level 2, depending on the design of the surfaces on the cam between the two levels of actuation abruptly (unsteady) or steady.

It comes with a curved surface on the respective cam not to a sudden change from an upper to a lower force application point on the active spring, but the force application points migrate during the Movement of the actuator approximately steadily from an upper force application point (level 1) towards a lower force application point (level 2) on the contact spring along.

The term "approximately continuous" means that the longitudinal movement of the actuating surface on the actuator takes place (as far as possible) uninterrupted along the longitudinal extension of the contact spring. In the prior art, such a transition from one to the other operating plane along the longitudinal extent of the contact spring is not given. The prior art does not change the operating level.

This creates the advantage over the EP1 121 700 B2 in that a choppy contact set characteristic is not generated, but a continuous contact set characteristic is achieved, which in a first embodiment can be formed from continuously extending, relatively straight curve branches, and in a second embodiment from curve branches which are bent approximately, to allow an even better rounded course of the contact set characteristic.

All the above definitions apply to the in FIG. 8 illustrated embodiment, in which the drive characteristic and a contact set characteristic are compared according to the prior art of a contact set characteristic according to the invention.

In a preferred embodiment of the invention, it is provided that the cams forming the actuating surfaces of the actuator occupy an angle to the vertical, provided that it is assumed that the actuator operates in a horizontal direction.

The size of the angle of the actuating surface in the direction of the vertical decides on the waypoint of the transition from the upper force application point to the lower force application point.

In a first embodiment of the invention, it is provided that this angularly inclined actuating surface is formed straight in itself.

In another embodiment of the invention, it is provided that this actuating surface is convex. This means that the contact set characteristic caused thereby is not formed from continuously continuing straight curved branches - as in a straight actuating surface - but that such a contact set characteristic additionally has rounded curve branches.

The achievement of rounded contact set characteristic curves branches still a more steady transition from one state of the contact springs is achieved in the other state, without the risk that unstable switching states in the intermediate path between these two contact states may be possible.

• Figur 1: schematisierter Schnitt durch ein Relais nach der Erfindung im Ruhezustand
• Figur 2: das Relais nach Figur 1 in Ruhestellung mit Darstellung weiterer Einzelheiten
• Figur 3: das Relais nach Figur 1 und 2 in einer Mittelstellung
• Figur 4: das Relais nach Figur 1 bis 3 in der Arbeitsstellung
• Figur 5: das Relais nach Figur 1 in der Ruhestellung unter Weglassung der Kontaktfedern
• Figur 6: eine vergrößerte Ansicht einer Betätigungsfläche an dem Betätiger in zwei verschiedenen Ausführungsformen
• Figur 7: eine dritte Ausgestaltung der Ausbildung der Betätigungsfläche an einem Betätiger
• Figur 8: die Kraft-Weg-Kennlinie eines Antriebssystems nach dem Stand der Technik in Gegenüberstellung zu einer Kontaktsatz-Kennlinie nach der Erfindung

In the following, the invention will be explained in more detail with reference to drawings illustrating several execution paths.
Show it:

• FIG. 1 : Schematic section through a relay according to the invention in the idle state
• FIG. 2 : the relay after FIG. 1 at rest with further details
• FIG. 3 : the relay after FIGS. 1 and 2 in a middle position
• FIG. 4 : the relay after Figure 1 to 3 in the working position
• FIG. 5 : the relay after FIG. 1 at rest, omitting the contact springs
• FIG. 6 : An enlarged view of an actuating surface on the actuator in two different embodiments
• FIG. 7 a third embodiment of the training of the actuating surface on an actuator
• FIG. 8 The force-displacement characteristic of a drive system according to the prior art in comparison to a contact set characteristic according to the invention

In the FIGS. 1 to 4 In general, an electromagnetically actuated relay is shown, wherein the individual contacts may be present in pairs or individually. According to FIG. 2 For example, there is a normally open contact 22, a further normally open contact 23 and a normally closed contact 24, which are all actuated jointly by an actuator 7. The actuator 7 is moved in the direction of arrow 5 in its working position and withdrawn by acting on its rear end spring 3 in the direction of arrow 6 in its rest position.

The drive of the actuator 7 is effected by an armature 2 which is pivotally received in a pivot bearing 4 in the region of a contact set carrier 1. The armature 2 is driven by a drive coil 21 in the direction of arrow 5.

In the illustrated embodiment, the actuator 7 consists of a flat insulating material and forms cams lying behind one another, 8, 10, 12, 14, wherein between the cams in each case a slot 9, 11, 13 is arranged.

In the slot 9 in front of the cam 8, the active contact spring 15 is arranged, which rests under its residual stress on the associated passive contact spring 18 and forms the NC contact 24 in the rest position.

Conversely, the active contact spring 16 forms a normally open contact 23 with the passive contact spring 19, the displacement of the active contact spring 16 by the cam 12 and an actuating surface 26 to be described later.

Finally, the make contact 22 is formed by the active contact spring 17, which is arranged in the rest position shown at a distance from the passive contact spring 20. The FIG. 3 shows a middle position of the movement of the actuator 7 in the direction of arrow 5, while the FIG. 4 represents the completely closed working position of the relay.

From the comparison of FIG. 3 with the FIGS. 1 and 2 It is clear that due to the inclined trained actuating surface 26 on the cams 8, 10, 12, 14 initially an upper force application point 25 of the actuator is defined, which engages the upper free end of the respective active contact spring 15, 16, 17.

With increasing displacement of the actuator 7 in the direction of arrow 5, the working position after FIG. 4 reached, and it can be seen that the force application point 25 has moved down into the force application point 27.

According to the invention is thus shown that by an obliquely to the vertical 35 directed actuating surface 26 of the actuator, which occupies an angle 36 with the vertical 35 (see FIG. 6 ), a displacement of the force application point 25 to the vertically underlying force application point 27 along the contact spring takes place.

Upon actuation of the contact spring in the upper force application point 25, a relatively low actuation force of the drive system is required, while in the operation of the respective contact spring 15-17 wandering towards the clamping point force application points 27 make a higher actuation force of the drive system required.

The FIG. 5 shows accordingly an actuator according to the invention, the obliquely inclined to the vertical actuating surfaces 26 shows. Incidentally, it is not necessary for the solution that the actuating surfaces 26 are formed at the active contact springs 15-17 actuating cam 8, 10, 12 inclined equal. They may also have a different inclination or shape.

In the embodiment according to FIG. 6 It is shown that instead of a straight trained and inclined at an angle 36 to the vertical 35 actuating surface 26 and a cambered actuating surface 26 'can be used, which is formed, for example, convex.

By the use of such a convex actuating surface 26 'rounded curve branches in the force-displacement diagram after FIG. 8 achieved, as explained below.

The FIG. 7 shows that instead of a convex actuating surface 26 'a concave actuating surface 26 "can be used, which means that the surfaces 26" do not come into engagement with the respective spring, but that only the intervention at the upper force application point 25 immediately with the Displacement of the actuator 7 in the direction of arrow 5 jumps to the attack on the lower force application point 27, without there being a transition here.

The FIG. 8 shows the advantages of the invention over the prior art.

It is a force-displacement diagram drawn, the numerical values are only to be understood as an example. They are in no way limiting to the present invention.

It is essential that in a relay with a coil drive system always an approximately curved drive characteristic 28 is reached, which is designated by the letter f and belongs to the prior art.

Furthermore, the shows FIG. 8 in that it belongs to the state of the art that discontinuously extending curve branches 31, 29, 37 form a contact set characteristic according to the prior art. Disadvantage of such a contact set characteristic with discontinuously continuing straight curve branches, however, is that a sudden transition in the operation of the individual active contact springs 15-17 must be taken into account, which is undesirable.

This is where the invention begins, which, due to the specially designed actuating surface 26 on the cams 8, 10, 12 of the actuator 7, instead proposes steadily continuing curve branches.

Upon initial actuation of the actuator 7, the prior art cam follower 31 results. Here, actuation of the active contact spring 15-17 begins at the upper force application point 25 at point s4. As a result, a straight or slightly inclined Kurvenast 32 is achieved, which is referred to collectively as a contact set characteristic curve 30 according to the invention.

It is characteristic that between the points s5 and s6 now a straight or - in convex actuating surface - a curved curved branch 32 is reached, which has a much greater distance from the existing drive characteristic 28 and thereby ensures a stable switching of the contact springs.

At the point s6, the upper force application point 27 becomes effective, and as the movement along the contact set characteristic 30 progresses, branching takes place at the point s6 in the steeper curve branch 33.

From the comparison of the contact set characteristic curve 29, which belongs to the prior art, in comparison with the contact set characteristic 30, which belongs to the invention, it will be seen that with much less effort, namely only by changing the actuating surfaces on the cam 8, 10, 12 of the actuator 7 a simple modulation or influencing the contact set characteristic is achievable. This was not possible with the prior art.

drawing Legend

1

Contact set carrier

2

anchor

3

feather

4

pivot bearing

5

arrow

6

arrow

7

actuator

8th

cam

9

slot

10

cam

11

slot

12

cam

13

slot

14

cam

15

active contact spring

16

active contact spring

17

active contact spring

18

passive contact spring

19

passive contact spring

20

passive contact spring

21

drive coil

22

NO contact

23

NO contact

24

NC

25

Force application point (upper)

26

Actuating surface (cam 10, 12, 14)

27

Force application point (lower)

28

Actuator characteristic

29

Contact set characteristic (St. d. T.)

30

Contact set characteristic (invention)

31

Curve branch (from 30)

32

curve branch

33

curve branch

34

arrow

35

vertical

36

angle

37

curve branch

Claims (8)

1. Electromagnetic relay comprising at least one contact set carrier (1) in which a number of contact springs (15, 16, 17, 18, 19, 20) are clamped on the foot side and in each case form paired make (normally open) and break (normally closed) contacts (22, 23, 24),

   - wherein at least one actuator (7) actuates the in each case active contact springs (15, 16, 17), the actuator being driven displaceably in the direction of its longitudinal extension by a magnet system (2, 3, 4),

   - wherein the actuator (7) forms cams (8, 10, 12, 14) lying one behind another,

   - wherein in each case a slot (9, 11, 13) is arranged between the cams (8, 10, 12, 14),

   - wherein the active contact springs (15, 16, 17) are arranged,

   - wherein the cams (8, 10, 12, 14) have formed actuating faces (26, 26', 26") for actuating the active contact spring (15, 16, 17) to be actuated in each case and which are inclined obliquely in relation to the vertical (35) of the actuator (7) with an angle (36),

   characterised in that the actuating faces (26, 26', 26") define an upper force application point (25) on the cams (8, 10, 12, 14) which acts on the upper free end of the respective active contract spring (15, 16, 17) on initial actuation of the actuator (7),
   and in that during the displacement of the actuator (7) in its working position on the active contact springs (15, 16, 17) the upper force application point (25) is displaced along the contact spring (15, 16, 17) to a lower force application point (27) lying vertically underneath it in the direction of the clamping location of the contact spring (15, 16, 17).
2. Relay according to claim 1, characterised in that the displacement from the first force application point (25) to the second force application point (27) by the actuating faces (26, 26', 26") on the cams (8, 10, 12, 14) of the actuator (7) is effected abruptly or steadily.
3. Relay according to one of claims 1 or 2, characterised in that the respective actuating faces (26) of the actuator (7) are embodied in the form of cams (8, 10, 12, 14).
4. Relay according to one of claims 1 to 3, characterised in that the actuating face (26) of the actuator (7) which is in each case inclined at the angle is in itself formed straight.
5. Relay according to one of claims 1 to 3, characterised in that some or all of the actuating faces (26') of the actuator (7) which are inclined at the angle are formed convex.
6. Relay according to one of claims 1 to 3, characterised in that some or all of the actuating faces (26") of the actuator (7) which are inclined at the angle are formed concave.
7. Relay according to one or more of claims 1 to 6, characterised in that some or all of the actuating faces (26) on the cams (8, 10, 12, 14) of the actuator (7) which actuate the active contact springs (15-17) are formed equally inclined.
8. Relay according to one or more of claims 1 to 7, characterised in that some or all of the actuating faces (26) on the cams (8, 10, 12, 14) of the actuator (7) which actuate the active contact springs (15-17) are formed unequally inclined.

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