DE102014117702A1 - Electric actuator - Google Patents

Abstract

The actuator (20) of the actuator device according to the invention comprises two electromagnets (1a, b) and yet can accelerate relatively large masses, ie apply high switching forces by being supported by springs (9), for example by compression springs (9), and optionally additionally by permanent magnets (6a, b).

Description

I. Field of application

The invention relates to an actuator, also called actuator whose moving part is to perform a linear or curved, preferably arcuate, movement.

II. Technical background

Such actuators are needed in the art for a variety of purposes to adjust a moving part, for example, between two end positions back and forth to adjust.

A typical application for this are ejector or ejector on a conveyor belt for products to secrete individual, for example, recognized as defective, products of this.

So far compressed air nozzles are often used for this, if the products to be removed are small and light, or mechanical ejectors, if they are larger.

The ejector is often biased by a spring in, for example, the ejection direction. However, the tensioning of the spring back into the starting position usually takes a relatively long time.

In this as well as other conceivable applications it is often important that the moving element, for example the ejector, can act very fast - in both directions -, which means a high acceleration of the inertial mass of the ejection from the rest position to the active position requires

The lower the masses to be moved, the lower the force required for this, or the faster the ejector can be accelerated.

A against the force of a spring, which holds the actuator, for example, in the activated position acting actuator such as an actuator must be designed to be strong enough to overcome the force of the spring can.

In other applications in which the applied force of the actuator can be much lower, an electromagnet is often used as the actuator, which acts in a direction and against the force of an opposing spring or alternately between two opposing electromagnets to be adjusted element ,

Although short switching times are achieved here, the achievable actuating forces are low, so that only objects with low mass that can be moved can be moved.

However, there are many other applications in which an actuator is needed, on the one hand short switching times, ie a high acceleration, allows and on the other hand, a high actuation force, either a high acceleration because of short switching times is necessary and / or the mass to be moved relatively large is.

The advantage of an electrically actuated actuator is, inter alia, that the structural complexity is relatively low and because of the electrical control of each individual actuator separately controlled in a simple manner and its switching time can be set.

Mechanically driven actuators, on the other hand, are far less flexible:
If, for example, an internal combustion engine attempts to change the opening or closing time of a valve as a function of certain operating parameters of the internal combustion engine during operation, this requires a great deal of mechanical effort, such as adjustment of the cam on the camshaft or the like.

III. Presentation of the invention

a) Technical task

It is therefore the object of the invention to provide an actuator device with at least one actuator which, despite its simple construction, offers high acceleration and / or high actuation force.

b) Solution of the task

This object is solved by the features of claims 1 and 24. Advantageous embodiments will be apparent from the dependent claims.

The actuator of the actuator device according to the invention consists of two relatively movable parts.

One part are the two electromagnets preferably mechanically fixedly connected to each other, each with a coil, the other part is the relatively movable yoke.

The yoke consists of a magnetizable material, in which preferably the relative permeability μr is at least 1000.

Preferably, the two electromagnets are fixedly arranged, that is attached to a component of the environment, while the yoke is movable.

The yoke is arranged in the distance between the two arranged in the longitudinal direction of each other and oppositely directed electromagnets and can move axially, so approach to one or the other electromagnets, in particular contact this contact, depending on which of the two electromagnets by means of current application currently is activated and attracts the yoke of magnetizable material to itself, which is independent of the current flow direction through the coil in particular without a permanent magnet present on the electromagnet.

Of course, the two electromagnets are only so far apart that their magnetic effect with activated electromagnet sufficient to reach the yoke, so that the yoke is still at least in its middle position in the middle between the two electromagnets in the effective range of both electromagnets, if this are energized.

The yoke is viewed in the longitudinal direction in the radial region of the respective coil, wherein the radial regions of the two coil are preferably aligned with each other. The yoke is preferably plate-shaped, in particular annular, with a transverse to the plate plane, in particular in a direction perpendicular to the longitudinal direction transverse direction, arranged.

In this way, the yoke can have a much lower mass than the two electromagnets, and thus the yoke can be accelerated out of a starting position very quickly by means of the magnetic field developed by one of the electromagnets in the axial direction.

In addition, between the movable part of the actuator, usually the yoke, and a fixed counter-holder - which may also be the immovable part of the actuator, for example, the two electromagnets, arranged two acting in opposite axial directions springs.

These springs are preferably compression springs.

The springs are dimensioned and arranged so that at one in the maximum approximated, in particular contacting, position of the yoke on one of the electromagnets and switching off the current through this electromagnet one of the springs - by means of tensile force or compressive force - the yoke of this electromagnet in the axial direction accelerated away and in particular moved at least to the middle between the two electromagnets and thereby very quickly far into the effective range of the other, now energized and thereby activated electromagnet brings the yoke now active and with increasing force to itself in the maximum approximated, especially contacting, situation, this being additionally supported by the genetic energy of the yoke.

In this way, a relatively large travel of the yoke can be realized with relatively weak electromagnets. Should this movement path still be insufficient for the desired application, then the movement path of the yoke can of course be converted by means of a transmission operatively connected thereto into an even larger working path of a desired working element, which is coupled to the transmission.

In which rest position with electroless electromagnets the yoke remains, depends on the choice of the spring forces of the two springs:
In most cases, the two springs are equally strong and with the same travel, so preferably identical, are selected. Then, when both electromagnets are de-energized, the yoke is held in the center between the two electromagnets by means of the forces of the two mutually opposing springs, at least when the longitudinal direction of the actuator is horizontal or substantially horizontal.

If the longitudinal direction of the actuator is upright or even vertical, the force of gravity of the yoke additionally acts in the rest position, so that, depending on its mass, the rest position of the yoke will be slightly below the center between the two electromagnets measured in the longitudinal direction.

A concern of the yoke on the underlying electromagnet can only be achieved if the concern of the force of the electromagnet is greater than the opposing force of the spring.

However, the force of the springs, in particular the lower spring when the longitudinal direction of the actuator is upright, is preferably even selected so that the spring is able to hold the yoke in a position raised from the lower, activated electromagnet. Because if this were not the case, could the lower spring when switching off the approaching magnetic field of the lower electromagnet repel this only slightly upwards.

In addition, the purpose of the invention is precisely to equip the yoke with the least possible mass in order to accelerate it quickly from one end position to the other end position and thus to be able to move it.

By means of such an actuator, therefore, relatively large masses which are fastened to the yoke can be accelerated rapidly and, with short switching times, the yoke and an attached mass, for example a working element, can be moved rapidly back and forth.

Viewed in the longitudinal direction, the coil is of course a ring closed in the circumferential direction, but its shape, viewed in the longitudinal direction, must be circular only preferably, but by no means compelling. Also in the form of a rectangle or other polygon wound coils are possible, but more expensive to manufacture.

The same applies to a possibly the coil on the radially outer side and / or the radially inner surrounding Flußleitkörper, with the aid of which the torroidal magnetic field generated by such a coil can be kept close to the coil and concentrated in the radial direction.

Preferably, the coil is also on the side facing away from the opposite coil, ie back, front side also surrounded by a Flussleitkörper, which preferably contacts the radially surrounding Flußleitkörper and in particular integrally formed therewith.

To guide the yoke can protrude from the yoke of each of its end faces at least one extending in the axial direction Jochschaft, which is then guided in a stationary part of the actuator via z. B. plain bearings.

A solution is that in the longitudinally viewed center each electromagnet has a through hole and the two through holes lie in the longitudinal direction and thus are aligned with respect to the two electromagnets to each other.

The yoke can now also in the center of each end face have a projecting Jochschaft which extends through the central passage opening in each one of the two electromagnets and can be guided therein or in a surrounding stationary housing. In this case, of course, the flux-conducting body possibly arranged on the front side of the electromagnet must likewise have a sufficiently large passage opening.

Another solution is that viewed in the longitudinal direction away from the cross-sectional area of the electromagnet, the yoke has one or more such axially projecting Jochschäfte on its end faces, and the or the Jochschäfte then not in the electromagnet, but in a stationary outside of the electromagnet stationary component , For example, a housing of the actuator, are guided.

However, the guide of the yoke can also be done in other ways, for example by the yoke protrudes in the radial direction over the cross-sectional area of the electromagnets and is guided there with its circumference in a stationary housing, but this causes a relatively large cross-sectional area of the yoke.

Another possibility is to provide from the yoke one or more in the radial direction abstrebenden Jochfortsatz, and to guide this Jochfortsatz in a stationary component, such as a housing of the actuator.

To the yoke starting from its rest position, so if both electromagnets were de-energized, very quickly by energizing one of the coils to pull up to this and then in the result also a very fast back and forth movement of the yoke between the two electromagnets by appropriate alternating current application To achieve the coils, when put into motion of the actuator which is a coil to which the yoke is to be used, subjected to a surge of very high voltage, in particular is very short, for example, much higher than the continuous load capacity of the corresponding coil , but only a maximum of 50 ms lasts.

This can for example be achieved with a circuit in which each of the individual coils is connected via a transistor to ground, while the other end of both coils is connected via a diode to the supply voltage and at the same time to a capacitor which is connected to that when the coils are switched off occurring induction voltage beyond the operating voltage can be charged. For this purpose, corresponding freewheeling diodes are provided, which are each connected with their anodes to the transistor-side end of each coil and with two cathodes on the plus-side terminal of the capacitor. Then connects another freewheeling diode, the operating voltage side terminals of the coil to ground. In this way, the induction voltage of the coils can be used when switching off via the freewheeling diode bridge to charge the capacitor beyond the operating voltage UC addition. A discharge of the charge of the capacitor to UC is prevented by the diode provided at the input of the circuit.

In a preferred embodiment, at least one permanent magnet in the active region of the electromagnet is arranged on the front, facing the other electromagnet, front end of one, in particular both, electromagnets, said permanent magnet having at least one, preferably exclusively, radial magnetic pole axes in the presence of a Permanent magnets on each of the two electromagnets in both permanent magnets is directed either radially inward or radially outward.

Preferably, therefore, the electromagnet is annular. The permanent magnet, in particular if it is of annular design, lies-in the axial direction-in the radial region of the coil, and / or also in the radial region of the possibly present flux guide body radially surrounding the coil inside and / or outside. In this case, the permanent magnet is not movable relative to the electromagnet, but arranged fixed thereto.

Preferably, the two permanent magnets are equally strong, have over the same magnetizable object an equal adhesive force.

The two permanent magnets can also be magnetically different in strength, namely in particular when the two springs are of different strengths, that is, have different degrees of spring force, which may be useful in particular for an upright actuator, in that case the upper permanent magnet can be stronger than the lower, or when the force of the actuator should be greater in one of the two axial directions than in the other.

The flow direction of the current can be chosen so that add the magnetic attraction of the electromagnet with that of the permanent magnet, so that the electromagnet and the permanent magnet together and thus particularly strong draw the yoke

By means of these permanent magnets is achieved that particularly high switching forces of the actuator can be achieved because z. As the tensile force or adhesive force of an activated electromagnet, the magnetic force of the permanent magnet is added or subtracted from it, depending on the direction in which the coil of the electromagnet is traversed by the current. For drawing the yoke, of course, the direction of current flow in the corresponding electromagnet is chosen so that it adds to the force of the permanent magnet. The reverse flow direction of the current in the coil is chosen so that the force of the permanent magnet is reduced or even canceled, so that the associated spring can accelerate the yoke away from this electromagnet into the effective range of the other electromagnet, which is then activated.

A further solution according to the invention is that of forming the yoke as a permanent magnet or of accommodating a permanent magnet in the yoke with respect to the polar direction of this permanent magnet as described above in the embodiment.

The advantage of this embodiment is that here by choosing the appropriate flow direction of the current through the coil, the yoke can be actively repelled by the activated electromagnet, while subsequently or simultaneously attracted by targeted choice of the flow direction of the current in the other coil of this can.

By this active repelling - preferably in addition by the force of one of the two optionally present springs - particularly short switching times of the actuator according to the invention can be achieved.

For the control of - usually alternating - current flow through the coils of the two electromagnets in the two prescribed solutions therefore an electrical control is used, which also controls the flow direction of the current through the respective coil.

The advantage of the circuit according to the invention is that with each switching operation, the charge of a capacitor is available in the circuit to build up in the coil at the next switching operation particularly quickly the necessary voltage in the coil and thus to reduce the switching time of the actuator.

For this purpose, the circuit comprises four transistors and two freewheeling diodes, as well as a capacitor and an additional diode. These are connected so that the coil is traversed by turning on a first pair of these transistors in one direction and by turning on the other pair of these transistors in the other direction, and when turned off, the coil via the freewheeling diodes charges the capacitor to induction voltage. The additional diode is used so that the current from the coil after their shutdown can only flow into the capacitor and not into the voltage source of the circuit.

An actuator device may comprise one or more interacting or single acting actuators.

The movable part of the actuator, usually the yoke, yes - usually mechanically - connected to a working element, which is to be moved by the actuator, such as an ejector or ejector.

As a rule, the working element is to be moved linearly back and forth, and can then be directly connected to the actuator, ie the movable part of the actuator, when the working path of the working element should not be greater than the path of movement of the actuator. Otherwise, a gear increasing the working distance must be interposed.

On the other hand, the working distance can be reduced in relation to the movement path of the actuator, and thereby the force which can be applied by the working element can be increased if particularly high forces are to be effected by means of the working element.

If, however, for example, a rotational movement of a working element to be effected, the movable part of the actuator by means of a connecting rod can cause the rotational movement of a rotary element by the connecting rod is articulated on the one hand with the rotary member away from the axis of rotation and on the other hand with the movable part of the actuator.

In this way, it is also possible to arrange a plurality of such rotary elements with mutually aligned axes of rotation in the direction of the axis of rotation one behind the other short distance, and to connect each of the rotary elements on the one hand with an actuator and on the other hand, of course, with a working element.

The rotary elements can be arranged at such a small distance from each other, which is significantly smaller than the extension of lying in the plane of rotation of the respective rotary member actuator measured in the direction of the axis of rotation of the rotary member.

This can be achieved by the actuators for the individual rotary elements are arranged offset from each other both in the circumferential direction with respect to the rotary member and in the direction of the axis of rotation of the rotary elements, so that they do not collide. As a result, actuator devices which are very short in construction can be constructed in the direction of the axis of rotation, so that prevailing cramped space conditions prevailing at the place of use of the respective working element can be mastered.

• – jeweils das mit diesem Aktuator wirkverbundene Pleuel an seinem Befestigungspunkt am Drehelement unter dem gleichen Winkel zur durch die Drehachse verlaufenden radialen Richtung stehen,
• – jeweils das Pleuel unter dem gleichen Winkel zu dem beweglichen, ihn antreibenden Teil des Aktuators, in der Regel dem Joch, stehen

denn nur dann ist sichergestellt, dass die Aktuatoren, die beispielsweise alle den gleichen Bewegungsweg besitzen, auch einen jeweils gleichen Drehwinkel des mit ihnen verbundenen Drehelements und damit einen gleichen Bewegungsweg des daran befestigten Arbeitselementes bewirken. It must be in the same functional position of the activators actuators, ie z. B. in the direction of the axis of rotation maximum approximate position of the movable part of the actuator, z. B. the yoke,

• In each case the connecting rods operatively connected to this actuator are at the same angle to the radial direction passing through the axis of rotation at its point of attachment to the rotary element,
• - Each of the connecting rod at the same angle to the movable, driving part of the actuator, usually the yoke, stand

because only then it is ensured that the actuators, for example, all have the same path of movement, also cause a respective same angle of rotation of their associated rotary member and thus a same path of movement of the attached work element.

With regard to the procedure for operating an actuator according to the invention, the object is achieved in different ways, depending on whether at no, only one or both electromagnets of the actuator, a permanent magnet is present:
If a permanent magnet is not present on either of the two electromagnets, the yoke remains in the rest position, ie in the case of electroless electromagnets, approximately in the middle of the distance in the axial direction between the electromagnets, and preferably also centered by the two counteracting springs. Whether this is the exact center of the distance, depends on the more or less upright position of the longitudinal direction of the actuator and thus the additional effect of the weight of the yoke.

From this position of rest, first that electromagnet whose front, the other electromagnet facing, face is deeper (in the horizontal direction of the actuator so one of the two electromagnets of your choice) energized, at the beginning with a very short surge with very high voltage supplied from the capacitor of the circuit of the actuator and the current stored therein, the yoke is attracted by this electromagnet.

Thus, for the first time, the yoke reaches the maximum position approximated to this first activated electromagnet, and the yoke can now be moved back and forth between the two end positions by alternately energizing the two electromagnets depending on the desired direction of movement of the yoke, so that So always one of the electric magnets to which the yoke is to move, is energized.

If, on the other hand, a permanent magnet is arranged only on one of the electromagnets, the electromagnet is normally close to the yoke at the magnet having the permanent magnets, held by the magnetic force of the permanent magnet, if this magnetic holding force with respect to the yoke is greater than the force of the opposite directed at least one spring.

If the latter is not the case, the yoke is approximated by the force of the permanent magnet, at least against the force of the spring slightly to the permanent magnets having electromagnet.

Now, first of all, the electromagnet lying closer to the yoke is supplied with current in such a flow direction that it first draws the yoke a maximum towards itself.

Subsequently, the flow direction of the current in this electromagnet is reversed, so that the holding force of the permanent magnet is reduced to this electromagnet, if necessary, is canceled, and thereby the associated spring is able to accelerate the yoke away from this electromagnet. At the same time or at the latest thereafter, the opposite electromagnet is energized to draw the yoke towards itself

Subsequently, the two electromagnets are then alternately switched so that the desired reciprocating motion of the yoke is effected.

The procedure, when both electromagnets each have a permanent magnet, differs in that the initial position, ie the rest position of the yoke, when both electromagnets are de-energized, can not be predicted, because after the current is disconnected, the yoke of that permanent magnet on the At the moment it was closer to the electroless circuit of both electromagnets, used and remains there by the force of the permanent magnet so long approximated, in particular adhere until the re-commissioning of the actuator.

Then, the commissioning with current application of that electromagnet to which the maximum approximates the yoke is started, and this causes a repulsion of the yoke, as described by way of example with only one equipped with permanent magnet electromagnet.

If, on the other hand, at least one permanent magnet is arranged in or on the yoke instead of the electromagnet, as described above, it can not be predicted in this starting position, in which initial position, that is to say rest position, the yoke is when both electromagnets are de-energized. For as a rule, the magnetic yoke then remains approximately at those electromagnets on which it was further approximated in Stromlosschalten.

Then, the commissioning with current application of that electromagnet, to which the maximum approximates the magnetic yoke is started, and this causes a repulsion of the yoke by appropriate selection of the flow direction of the current through the coil.

Subsequently, in this coil, the direction of the current flow is changed, whereby the magnetic yoke is repelled, and subsequently or simultaneously, in the other coil, a current flow in such a flow direction is switched on, that the magnetic yoke is used on this other electromagnet.

c) embodiments

Embodiments according to the invention are described in more detail below by way of example. Show it:

1a C: different functional positions of a first type of actuator,

2a , b: cross-sectional views through this design of the actuator,

3a FIG. 4: a longitudinal section through a second basic design of the actuator in a first physical variant, FIG.

3b : the second fundamental physical form in another physical variant,

4 a longitudinal section through a third basic design of the actuator,

5a FIG. 2: a section through an actuator device with a plurality of actuators, FIG.

5b a side view of the actuator of the 5a .

6 an electronic circuit for driving one of the aforementioned actuators without reversing the direction of the current,

7 an electronic circuit for driving one of the aforementioned actuators with reverse current direction.

The first basic design of the actuator according to the invention 20 according to 1a consists of two aligned electrical coils 2a , b, each concentric about a common axial direction 10 , the direction of movement 10 of the actuator 20 , run, in this axial direction 10 however, are spaced from each other.

The current flow through these two coils 2a , b can be independently switched on and off, for example, by an electrical circuit, as in 6 is shown and explained.

The two coils 2a , b thus each act as an electromagnet 1a , b, and are for this purpose preferably on the radial inside and outside as well as the opposite of the coil, for example 2a opposite rear side of a Flussleitkörper 16 surrounded, in this case in the longitudinal direction 10 considered channel-shaped circumferentially formed, and in the middle of each one central, ie on the coil axis 10 ' lying, passage opening 17 having. The flux conducting bodies 16 in this case are slightly in the direction of the opposite electromagnet 1a , b over the coil 2a , b ago, but can flush with these ends.

In the axial distance 12 between the two facing front end faces of the electromagnets 1a , b is in a transverse plane 11 , preferably one perpendicular to the longitudinal direction 10 lying transverse plane 11 , a plate-shaped yoke 4 made of a magnetizable material.

The plate-shaped yoke 4 is in the axial distance 12 in the axial direction 10 moved back and forth, which by activating each one of the two electromagnets 1a , B is done by the coil 2a , b is energized, and thereby by the electromagnet 1a , b magnetic field formed the magnetizable yoke 4 towards itself, preferably until contacting the corresponding front end side of the corresponding electromagnet 1a , b.

From the yoke 4 protrude in the longitudinal direction 10 on both sides in each case a yoke shaft 14a . 14b from which the respective passage opening 17 in the electromagnet 1a , p penetrates and beyond. Each supernatant possesses in the supernatant 14a , b a radially outwardly projecting stop 13 for supporting a yoke shaft 14a or 14b surrounding helical compression spring 9 that are on the outside of this stop 13 supported and on the other side on the inside of a counter-holder 15 as well as the electromagnets 1 is formed stationary and in this case part of the electromagnets 1 surrounding housing 18 is.

Both yoke shafts 14a , b are formed so long that they are the respective end face of the housing 18 So the counterpart 15 , Pass through a corresponding passage opening and thus are additionally stored in this counter-holder, and not only in the through hole 17 the two electromagnets 1a , b, which is not mandatory, such as 1c shows.

The plate-shaped yoke 4 runs in the transverse direction over the entire front end face of the mutually aligned electromagnets 1a , b, and thus over the entire surface to the outer periphery of the electromagnets 1 , which in this case at the same time the inside of the case 18 is to which the yoke 4 course, is slightly spaced to avoid frictional forces.

The housing 18 surrounds the two electromagnets 1a , b and is in the radial direction preferably close to this, in any case, is fixed to the electromagnet 1a , B connected, and leaves in the two axial directions on the back of the two electromagnets sufficient space for the respectively accommodated there compression spring 9 and the stop 13 of the yoke shaft 14a , b.

In 1a is the lower electromagnet 1b current flowing through it, so the yoke 4 at the front, in 1 upper, front side of the electromagnet 1b is applied.

The lower electromagnet 1b must in this case the lower compression spring 9 with the help of the stop 13 against the lower counterholder 15 squeeze together, so develop a sufficiently large magnetic force for this purpose.

In 1a is the direction of flow through the coil 2 B of the lower electromagnet 1b in this case chosen so that forms a torroidales magnetic field, which is inside the coil 2 B from below, ie the back of the electromagnet, upwards, ie to the front and in the direction of the yoke 4 , runs.

Also with reverse current flow direction in the coil 2a However, b would make the electromagnet the yoke 4 use.

In 1b the reverse case is shown, namely that the coil 2a of the upper electromagnet 1a is traversed by electricity and therefore the yoke 4 up to the contact with the front, in this case lower end of the upper electromagnet 1a has used and holds, as long as the current flow through this coil 2a of the upper electromagnet 1a stops.

1c shows the de-energized state of the actuator 20 in which none of the two electromagnets 1a , b is activated, so its coils 2a , b are not traversed by electricity.

In this rest position is - especially if the actuator 20 with its direction of movement 10 located in the horizontal - the yoke 4 by means of the oppositely directed, in this case equally strong, compression springs 9 in the middle of the distance 12 between the two electromagnets 1a , b held, centered by the force of the two equally strong against each other acting compression springs 9 ,

In this rest position, the two attacks have 13 in each case such an axial distance to the back of the adjacent electromagnet 1a , b, that from this position of rest the approach of the yoke 4 , in particular the contacting, on the end face of each of the two electromagnets 1a , b is possible.

It lies in the nature of an electric coil 2 in that the turns thereof are of annular design and in this case the coil axis 10 ' surrounded concentrically. Accordingly, this also applies to the coil 2 each surrounding flux collector 16 and preferably also for the housing 18 ,

Whether the entire arrangement, however, in the longitudinal direction 10 , the direction of movement of the actuator 20 , considered as in the 2a , b shown in cross-section, is circular in shape, as in 2a represented, or has another shape, such as the square shape, as in 2 B shown, is irrelevant to the function and has only influence on the production of the electromagnets and thus the actuator 20 :
In 2a So, on the one hand, has the yoke shaft 14a a round cross-section, and likewise the central passage opening 17 in this yoke shaft 14a is guided.

Also the coil 2 has a round, so circular, cross-section, and also this coil 2 on its radially outer side and inner circumferential walls of the enclosing Flußleitkörpers 16 ,

On the outside is this entire electromagnet 1 from a likewise annular in this direction in cross-section housing 18 added.

In the rectangular design according to 2 B is only the yoke shaft 14a equipped with a round cross-section and the leading him central passage opening 17 , The sink 2a on the other hand has both an outer cross-sectional contour and an inner cross-sectional contour in the form of a square, which are concentric with each other, and the same applies to the outer and inner wall of the surrounding Flußleitkörpers 16 as well as the housing 18 ,

The 3a , b show a second basic design of the actuator according to the invention 20 mainly characterized by the first basic design of the 1a -C distinguishes that on the front, so the other electromagnet 1 facing side of each of the two coils 2a , b in each case a disc-shaped annular permanent magnet in this case 6a , B is arranged, both permanent magnets 6a , B have a radial magnetic pole direction, in this case with the north pole N radially outboard and the south pole S radially inwardly.

This is superimposed when activating one of the coils 2a , b that of this current-carrying coil 2a , b generated magnetic field with the magnetic field of close to this coil 2a , b, namely in the magnetic effective range of this coil 2a or b arranged, permanent magnets 6a or 6b ,

By selecting the flow direction of the current in the respective coil 2a , b can be determined whether the magnetic fields of the activated coil and the associated permanent magnet 6a or add or subtract b.

In the 3a and b is the coil 2 B of the respective lower electromagnet 1b Flowed through by current in such a direction that in the center, so on the coil axis 10 ' that of the activated electromagnet 1b generated torroidal magnetic field from the back of this lower electromagnet 1b that is, from below, to its front and in the direction of the yoke 4 runs, which also consists of a magnetizable material in this design.

This adds up the magnetic fields of the activated electromagnet 1b and the associated permanent magnet 6b , and pull the yoke 4 especially strong, so down.

The upper electromagnet 1a is not activated, but is only activated - at about simultaneous de-energizing circuit and deactivation of the lower electromagnet 1b - if the yoke 4 to be moved upward, attracted by the magnetic field of the upper activated electromagnet 1a , Also in this case, preferably, the current flow through the coil 2a when activated so chosen that the magnetic force of the coil 2a , the activated electromagnet 1a and the upper permanent magnet 6a add.

The respective electromagnet 1 in terms of current flow direction through its coil 2 To switch so that the magnetic force of the activated coil 1 and the associated electromagnet 6a , b subtract from each other, in this case makes sense only if the attraction of the respective permanent magnet on the yoke 4 should be reduced or canceled, in order to detach the yoke and accelerate in the direction of the other electromagnet 1 by means of the force of the spring 9 to enable.

For the operation of this design, however, an electrical circuit for controlling the current flow through the coils is still for the reasons mentioned 2 necessary, the one defined flow direction through the respective coil 2 causes in the sense of adding magnetic forces of activated electromagnet 1 and the associated, adjacent permanent magnet 6a , b.

One way of such a circuit shows 7 and will be explained below.

In addition, next to the other structure of the electromagnets 1a , b and the other function - the actuator differs 20 also in its physical shape, as seen in this longitudinal section:
So own in 3a the electromagnets 1a , b no central passage opening 17 , and accordingly stand by the yoke 4 on both sides in each direction at least two Jochschäfte 14a . 14b before, however, are arranged radially far enough outside that they are laterally to the electromagnet 1a , B pass by, and in turn at the corresponding axial position in each case a stop 13 have, in each case a compression spring 9 rests on the other side on the inside of the counter-holder 15 , the respective front panel of the housing 18 , supports.

In the longitudinal section of the 3a are on each end of the yoke 4 , which is also in this case over the entire cross-sectional area of the two mutually aligned electromagnets 1a , b is located, two Jochschäfte 14a , b, longitudinally viewed, however, can be over the circumference of the electromagnets 1a , b on each side of the yoke 4 definitely more, for example, three or four, Jochschäfte be arranged.

However, it must not be forgotten that the goal is to move the mass of the yoke to be moved 4 including any existing Jochschäfte 14a To keep b as low as possible in order to accelerate this as quickly as possible when switching the actuator.

The yoke 4 is so in this design by means of Jochschäfte 14a , b no longer in the passage opening through the electromagnets 1a , b stored, but only by means of the end portions of his Jochschäfte 14a , b in the front sides of the housing 18 ,

3b shows a design that is different from that of 3a differs in that of the plate-shaped yoke 4 from in this longitudinal section two facing away Jochfortsätze 19 out through the side wall of the housing 18 extend through and in corresponding slots in this housing 26 are guided.

About the circumference of the actuator 20 are preferably not only two opposite, but over the circumference more than two, for example three or four, slots 26 and yoke processes guided in it 19 present to the yoke 19 safe and without jamming in the case 18 respectively.

The likewise over the circumference several times, preferably three or four times, existing compression springs 9 in this case, they lean on the yoke 4 radially outside the electromagnets 1a , b off and on their opposite side at a stop 13 coming from the inside of the case 18 radially in the direction of the electromagnet 1 protrudes inwards.

The rest position of the yoke, not shown 4 - So if both electromagnets 1a , b are de-energized and therefore inactive - is in this case, however, another, because the yoke 4 remains at that electromagnet 1a or b, which was last activated, adhere due to the magnetic holding force of this electromagnet 1b arranged permanent magnets, in 3b the permanent magnet 6b , there 3b this de-energized state of both electromagnets 1 represents.

The in 4 illustrated actuator 20 is physically structured as in the 1a presented to c, with the difference that in the design of the 4 the yoke 4 , so preferably only in a transverse plane 11 lying, plate-shaped part of the yoke 4 , consists of one or more permanent magnets.

The polar direction of this one or more permanent magnets of the yoke is 4 extends radially at all points of the circumference in the same radial direction, in the case shown from the inside out, so at any point of the circumference always with the same pole on the inner circumference or in the center and the same pole on the outer circumference.

In the present case, therefore, the south pole S and the inner circumference or the center of the north pole N are arranged on the outer circumference. If it is around several, for example, distributed radially distributed over the circumference, bar magnets, this is true for the individual bar magnets.

This embodiment makes it possible by appropriate choice of the flow direction of the current through the coil 2a , b this permanent magnetic yoke 4 through the electromagnet 1 attracted or repelled magnetic force developed.

In the in 4 In the case illustrated, the current flow is chosen so that the polar axis of the electromagnet 1b formed magnetic field in the center in the axial direction from north to south to the yoke 4 runs, which has formed in the center or on the inner circumference of the north pole N.

By this flow direction of the current through the coil 2 B becomes the yoke 4 to the activated lower coil 2 B and the speaking electromagnet 1 used.

By reversing the flow direction of the current in this coil 2 B can the yoke 4 be repelled magnetically and thereby - preferably at the same time corresponding current flow direction in the other, in this case the upper coil 2a - be used on these.

If for the control and Stromeaufschlaung the electromagnets 1a , b and their coils 2a , b, for example, the circuit according to 7 is used, ie a circuit which can cause a reversal of the direction of the current and additionally causes a current surge fed from the capacitor K of this circuit when switching the current direction, can with such an actuator 20 and the associated circuit very fast accelerations of the yoke 4 and thus very short switching times of the actuator 20 be achieved.

In the 5a , b is an actuator device shown, the several, in this case three, actuators 20 includes.

In this case, each one of three ejectors by means of one actuator 24 , which are to perform a pivoting movement, in the direction of the pivot axis 22 in quick succession in a z. B. production or packaging system can be used.

The distance of the ejector 24 is smaller than the diameter, ie the width B in the direction of this desired distance, the actuators to be used 20 ,

In the direction of the axis of rotation 22 should the ejector 24 However, be arranged lying one behind the other, so their pivoting paths coincide in this line of sight.

This can be achieved by the respective actuator 20 not directly on the working element, in this case the ejector 24 , but affects each of the ejector 24 on a rotary element 23 which is pivotable about the axis of rotation 22 , is rotationally fixed and projects radially from this, as in 5a shown.

To now this successive ejector 24 yet individually and independently of each other, but to be able to move the same pivoting range, engages each of the rotating elements 23 eccentrically and on the same radius in each case a connecting rod 21 hinged, which with its other end also hinged to the yoke shaft 14a each of an actuator 20 connected is.

• – zum einen der Winkel α1, in dem der Jochschaft 14b zum Pleuel 21 steht – betrachtet in Richtung der Drehachse 22 – wenn sich auch das Drehelement 23 und damit der Auswerfer 24 in seiner einen Endlage befindet, bei allen Aktuatoren 20 gleich ist und
• – andererseits muss der Pleuel 21 in dieser Lage in einem Winkel α2 zur axialen Richtung durch den Befestigungspunkt des Pleuels 21 am Drehelement 23 angeordnet sein, und für die analoge Stellung auch dieser Winkel α2 für alle drei Einheiten, also Aktuatoren 20 mit Pleuel 21 und Drehelement 23, übereinstimmen.

It is essential that this arrangement is such that in the same starting position, so in this case with fully extended Jochschaft 14a

• - On the one hand, the angle α1, in which the yoke shaft 14b to the connecting rod 21 stands - considered in the direction of the axis of rotation 22 - If also the rotating element 23 and thus the ejector 24 in its one end position, with all actuators 20 is the same and
• - On the other hand, the connecting rod 21 in this position at an angle α2 to the axial direction through the attachment point of the connecting rod 21 on the rotary element 23 be arranged, and for the analog position also this angle α2 for all three units, ie actuators 20 with connecting rod 21 and rotary element 23 , to match.

The goal is that by a stroke of an actuator always the same pivot angle of the effector associated with it is effected.

Under certain circumstances, this can be achieved without the above conditions by the angle and the lengths, for example, the connecting rod 21 to be changed.

In 6 is a suitable driver circuit shown for driving the coils 2 . 2 ' in those embodiments of the present invention in which no permanent magnets are used.

If no permanent magnets are used, it is not necessary to reverse the current direction in the coils. Rather, it is required, each of the coils 2a to be able to control b separately.

Nevertheless, should be achieved according to the invention that when switching off the coils 2a , B occurring induction voltage can be used in this case for charging a capacitor K on the operating voltage UC addition. In this case, in each case one transistor T2, T2 'is sufficient for driving one coil each 2a , b, since no complex bridge circuit must be provided to reverse the current direction.

In the present embodiment of the 6 the transistors T2, T2 'are designed as NPN transistors whose emitters are connected to ground, and which each have one end of the coils 2a , b in each case through to ground, if in the coil current is to flow. The other connections of the coils 2a , b are connected via a diode ZD (anode to UC) to the supply voltage UC.

With the elements described so far, one of the coils 2a , b are supplied with power when the transistors T2, T2 'are driven in accordance with a control ST. Would you like to advantageously also in this case, the induction voltage when switching off the coils 2a , b, use a between ground and operating voltage side terminals of the coils 2a It is absolutely necessary to use the additional diode ZD already described, which prevents the discharge of the charge K of the capacitor K beyond the UC into the voltage source. In addition, one needs in each case a freewheeling diode D1, D1 'to each transistor T2, T2', which connects the collector of the respective transistor with a terminal of the capacitor to be charged (anode at the collector). The other terminal of the capacitor K to be charged is connected to ground.

The spools 2a , b, if appropriate via a further transistor T1 with protective diode D3, which can additionally be provided to regulate the current via a corresponding pulse width modulation, in order to overload the coils 2a , b and still have sufficient power reserves in the event that the first time in commissioning the circuit from the de-energized state of the anchor is in the middle position.

Furthermore, a further free-wheeling diode D2 is provided which, with its cathode, is connected to the other terminal of the coils 2a , b and its anode connected to ground. The arrangement of the freewheeling diodes D1, D1 'and D2 is achieved according to the invention, that in the coils 2a , B resulting induction voltage charges the capacitor K beyond UC, so that the obtained in this way higher voltage for re-driving the coils 2a , b is available.

In 7 the circuit is shown, with the admission, ie wiring of a coil 2a or b in either one of the two possible directions of current flow through the coil 2a or b is enabled:
The circuit shown is connected to a voltage source which supplies the circuit with a DC voltage UC. The power supply of the circuit preferably has a supply voltage of 24 volts.

The circuit has four transistors T1 to T4 in a bridge circuit, which may be bipolar transistors, field-effect transistors or metal-oxide-semiconductor field-effect transistors. In this case, the transistors T1 and T3 form a first half-bridge and the transistors T2 and T4 form a second half-bridge.

The circuit also has the coil 2 of the actuator, which has already been shown in the previous figures. The transistors T1 and T3 are connected in series with respect to the power supply of the circuit. The transistors T2 and T4 are also connected in series with respect to the power supply of the circuit and connected in parallel with the transistors T1 and T3.

The sink 2 is connected on one side with the electrical connection between the transistors T1 and T3, ie with the emitter of the transistor T1 and the collector of the transistor T3. The other side of the coil 2 is electrically connected to the electrical connection between the transistors T2 and T4, ie with the emitter of the transistor T2 and the collector of the transistor T4.

The sink 2 preferably has an inductance of 0.1 to 0.2 Henry, preferably 0.15 Henry.

The circuit also has three diodes D1, D2 and ZD. The additional diode ZD is located at the connection of the circuit to the power supply, with its anode is connected to the power supply and its cathode to the line leading to the other components of the circuit.

The diode D1 is connected in anti-parallel to the transistor T1. The diode D2 is connected in anti-parallel to the transistor T2. The diodes D1 and D2 serve as freewheeling diodes for the transistors T1 and T2, ie with a passage direction opposite to the passage direction of the associated transistors, wherein in each case their anodes corresponding to the electrical line between the transistors T1 and T3 of the first half-bridge and the electrical Line between the transistors T2 and T4 of the second half-bridge are connected.

The diodes D1 and D2 may have a slip voltage, ie a threshold voltage U _S of 0.3 V and a blocking voltage U _R of 400 V. The diode Z _D may have a slip voltage U _S of 0.3 V and a reverse voltage U _R of 400 V.

Finally, the circuit still has a capacitor K on. This is connected in parallel to the first half-bridge with the transistors T1 and T3 and parallel to the second half-bridge with the transistors T2 and T4. The capacitor is preferably according to the inductance of the coil 2 designed. It therefore preferably has a capacity in the range from 1 μF to 22 μF, preferably 4.7 μF.

The following explains the functional principle of the circuit shown:
By turning on the transistors T1 and T4 is in the presence of the supply voltage UC, the winding of the coil 2 excited with positive current direction. In this case, the transistors T2 and T3 are turned off.

When turning on the transistors T2 and T3, when the transistors T1 and T4 are turned off, on the other hand, the windings of the coils 2 energized with negative current direction. Thus, the coils can 2 be energized in both current directions, which - as has already been explained to the previous figures - through the coils 2 Magnetic fields can be built in opposite directions.

When turning off the current through the winding of the coil 2 That is, when, for example, the transistors T4 and T1 are turned off, with the transistors T3 and T2 turned off, the capacitor K is charged via the flywheel diodes D1 and the transistor T4 also acting by means of the induction voltage.

This effect is due to the inductance of the coil 2 due to which the coil 2 initially shuts off the current flow when it is switched off. The further current flow, caused by the coil 2 , is in the magnetic field of the coil 2 attributed stored magnetic energy. Depending on the current flow direction, this current can flow back in the circuit via one of the diodes D1 or D2 and one of the transistors T3 or T4 and charge the capacitor Kover Uc.

Diode ZD prevents this current from flowing through the power supply of the circuit and possibly damaging it.

By charging the capacitor K is for a renewed switching operation, a much higher voltage, for example, more than 150 V, than that of the normal power supply, d. H. the voltage UC, available.

Thus, the flow of current through the coils 2 , which is first slowed down by the inductance, are increased when they are turned on in a shorter time and thus the excitation of the windings of the coils 2 done in less time. As a result, therefore, in a shorter time required for the switching speed of the actuator magnetic field of the coil 2 built up.

For example, the actuator, and preferably its circuitry, is designed to switch within 2-3ms.

LIST OF REFERENCE NUMBERS

1

electromagnet

2a, b

Kitchen sink

3

circuit

4

yoke

5a, b

front

6a, b

permanent magnet

7

Pol-axis

8th

radial area

9

compression spring

10

Longitudinal direction, axial direction, direction of movement

10 '

coil plane

11

transverse plane

12

distance

13

attack

14a, b

yoke shaft

15

backstop

16

flux conductors

17

Through opening

18

casing

19

Yoke extension

20

actuator

21

pleuel

22

axis of rotation

23

rotating member

23 '

plane of rotation

24

ejector

25

attachment point

26

slot

α

angle

b

width

B

width

T1-T4

transistor

D1-D4

Freewheeling diode

K

capacitor

ZD

additional diode

Claims (26)

(Without permanent magnets) Actuator device with at least one actuator ( 20 ), which - at least one electromagnet ( 1a ) with a coil ( 2a ) in the longitudinal direction ( 10 ) lying coil axis ( 10 ' ), - an electrical circuit ( 3 ) for controlling the current flow in the coil ( 2 ), - a relative to the at least one electromagnet ( 1 ) longitudinal ( 10 ) movable yoke ( 4 ) of magnetizable material in the effective range of the electromagnet ( 1 ), characterized in that - two electromagnets ( 1a , b) each with a coil ( 2a , b) in the longitudinal direction ( 10 ) with a distance ( 12 ) one behind the other and with respect to a transverse plane ( 11 ) to the longitudinal direction ( 10 ) are axially opposite each other, - the yoke ( 4 ) in the distance ( 12 ) is arranged and - between the movable part of the actuator, the electromagnet ( 1a , b) or the yoke ( 4 ), and a fixed counter-holder ( 15 ) two springs acting in opposite axial directions ( 9a , b) are arranged. Actuator device according to claim 1, characterized in that the springs ( 9a , b) compression springs ( 9a , b) and / or one spring each ( 9a , b) on each end face ( 5a , b) of the movable part of the actuator is arranged. Actuator device according to one of the preceding claims, characterized in that from both end faces of the yoke ( 4 ) longitudinal ( 10 ) at least one yoke each ( 14a , b) protruding, in particular the movable part of the actuator, in particular one of the electromagnets ( 1 ) and its coil ( 2 ), through whose central passage opening ( 17 ) longitudinal ( 10 ) penetrates. Actuator device according to one of the preceding claims, characterized in that the two electromagnets ( 1a , b) are stationary and the yoke ( 4 ) is arranged to be movable. Actuator according to one of the preceding claims, characterized in that the actuator device ( 4 ) in the radial area of the coil ( 2 ) is arranged. Actuator device according to one of the preceding claims, characterized in that the yoke ( 4 ) plate-shaped in the transverse plane ( 11 ) lying, and in particular is annular. Actuator device according to one of the preceding claims, characterized in that the coil ( 2 ) on the radial outside and / or the radial inside of a flux guide body ( 16 ) is surrounded. Actuator device according to one of the preceding claims, characterized in that the coil ( 2 ) also at the opposite of the coil ( 2 ) facing away from a flux guide ( 16 ) is surrounded. Actuator device according to one of the preceding claims, characterized in that the end-side flux guide body ( 16 ) also has a central passage ( 17 ), which is large enough, the yoke shaft ( 14a , b) pass through and this particular in the axial direction ( 10 ) respectively. Actuator device according to one of the preceding claims, characterized in that the two springs ( 9a , b) are equally strong. Actuator device according to one of the preceding claims, characterized in that the two springs ( 9a , b) have a lower spring force than the adhesive force of the yoke ( 4 ) on which the yoke ( 4 ) attracting, activated electromagnets ( 1a , b) Actuator device according to one of the preceding claims, characterized in that each of the springs ( 9a , b) is sufficiently strong to reduce the weight of the yoke ( 4 ) where appropriate, including the Jochschäfte ( 14a , b) to wear (with permanent magnets in the electromagnet) Actuator device according to one of the preceding claims, characterized in that - at that end face ( 5a , b) the electromagnet ( 1a , b), in particular its coil ( 2 ), and in particular on each of the two electromagnets ( 1a , b), the opposite electromagnet ( 1a , b) is adjacent, at least one permanent magnet ( 6a , b) is arranged, - wherein the permanent magnet ( 6a , b) a radial polar axis ( 7 ), which in all permanent magnets ( 6a , b) has either radially inward or radially outward - and in particular the circuit ( 3 ) is also capable of determining the direction of current flow through each of the two coils ( 2 ) to control. Actuator device according to one of the preceding claims, characterized that the at least one permanent magnet ( 6a , b) is annular. Actuator device according to one of the preceding claims, characterized in that the at least one permanent magnet ( 6a , b) in the radial area ( 8th ) of the coil ( 2 ) is arranged. Actuator device according to one of the preceding claims, characterized in that the at least one permanent magnet ( 6a , b) fixed to the electromagnet ( 1a , b), in particular its flux guide body ( 16 ), connected is. Actuator device according to one of the preceding claims, characterized in that the two permanent magnets ( 6a , b) are equally strong. Actuator device according to one of the preceding claims, characterized in that the two springs ( 9a , b) have different strengths and the associated permanent magnets ( 6a , b) are of different strength, in particular in that the stronger permanent magnet ( 6a ) of the stronger spring ( 9a ) is arranged adjacent and / or in an upright actuator or upper permanent magnet ( 6a ) is stronger than the lower one. (With permanent magnet in the yoke) Actuator device according to one of the preceding claims, characterized in that - the yoke ( 4 ) at least one permanent magnet ( 6a , b) whose pole axis radially either from the outside to the inside at all points of the circumference at which a permanent magnet is located, radially from inside to outside or at all points where a permanent magnet is located, and - the electrical circuit ( 3 ) comprises a capacitor (K) capable of rapidly transferring the current stored in it to one of the coils ( 2 ) (Actuator device) Actuator device according to one of the preceding claims, characterized in that the actuator ( 20 ) by means of a connecting rod ( 21 ) with one about a rotation axis ( 22 ) rotatable rotary element ( 23 ) is operatively connected, wherein the actuator ( 20 ) in the plane of rotation ( 23 ' ), in which the rotary element ( 23 ) turns. Actuator device according to one of the preceding claims, characterized in that on the rotary element ( 23 ) rotatably a working element, in particular an ejector ( 24 ) is arranged. Actuator device according to one of the preceding claims, characterized in that a plurality of independently rotatable rotary elements ( 23 ) in the direction of the axis of rotation ( 22 ) are arranged one behind the other, in particular in the direction of the axis of rotation ( 22 ) each have a smaller width (b) than the width (B) of the actuator ( 20 ) viewed in the same direction, and the respective rotary elements ( 23 ) operatively connected actuators ( 20 ) viewed in the direction of the axis of rotation ( 22 ) offset from one another and in the circumferential direction to the axis of rotation ( 22 ) are offset from one another. Actuator device according to one of the preceding claims, characterized in that in the respective same functional position, for example in the direction of the axis of rotation ( 22 ) maximum approximated position of the yoke ( 4 ), with this actuator ( 20 ) operatively connected connecting rods ( 21 ) at its attachment point ( 25 ) at the same angle (α) to the radial direction extending therefrom, starting from the axis of rotation ( 22 ) runs Method for starting the actuator of the actuator device, which is not used in any electromagnet ( 1a , b) a permanent magnet ( 6a , b), so that the yoke ( 4 ) with electroless electromagnets ( 1a , b) in the middle of the distance ( 12 ) through the springs ( 9a , b) remains centered in a rest position, by - first the electromagnet ( 1b ) with the deeper end face ( 5b is subjected to a very short current surge with very high voltage that the yoke ( 4 ) is used by him as much as possible, - then this electromagnet ( 1b ) de-energized and the other electromagnet ( 1a ) is energized so that the yoke ( 4 ) from the other electromagnet ( 1a ) is attracted, - alternately the two electromagnets ( 1a , b) be energized depending on the desired movement of the yoke ( 4 ). Method for starting up the actuator of the actuator device, which is in both electromagnets ( 1a , b) at least one permanent magnet ( 6a , b), so that the yoke ( 4 ) with electroless electromagnets ( 1a , b) on one of the two preferably equally strong permanent magnets ( 6a , b) one of the two electromagnets ( 1a , b) is applied, depending on which of the two permanent magnets ( 6a , B) the yoke ( 4 ) was more closely approximated when the actuator was de-energized by first - the electromagnet ( 1b ), from which the yoke ( 4 ) is maximally removed in the rest position, is acted upon in such a flow direction with current that the yoke ( 4 ) is attracted to it, - thereafter this electromagnet ( 1b ) de-energized and the other electromagnet ( 1a ) is energized in such a flow direction, that the yoke ( 4 ) is attracted by him, - in alternation, the two electromagnets ( 1a , b) be energized depending on the desired movement of the yoke ( 4 ). Method for starting up the actuator of the actuator device, which is in the movable part, in particular in the yoke ( 4 ), at least one permanent magnet ( 6a , b), so that the yoke ( 4 ) with electroless electromagnets ( 1a , b) on one of the two electromagnets ( 1a , b) is applied, depending on which of the two permanent magnets ( 6a , b) the yoke ( 4 ) was more closely approximated when the actuator was switched off by - first the electromagnet ( 1b ), where the yoke ( 4 ) is in the rest position or maximum approximated, is applied in such a flow direction with power that the yoke ( 4 ) is repelled by him, - thereafter this electromagnet ( 1b ) de-energized and the other electromagnet ( 1a ) is energized in such a flow direction, that the yoke ( 4 ) is attracted by him, - in alternation, the two electromagnets ( 1a , b) be energized depending on the desired movement of the yoke ( 4 ).

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