EP3918619A1

EP3918619A1 - Electromagnetic actuator

Info

Publication number: EP3918619A1
Application number: EP19739854.8A
Authority: EP
Inventors: Daniel THEUSSL; Gerhard Schöner; Ewald Lampl
Original assignee: MSG Mechatronic Systems GmbH
Current assignee: MSG Mechatronic Systems GmbH
Priority date: 2019-01-28
Filing date: 2019-06-27
Publication date: 2021-12-08
Anticipated expiration: 2039-06-27
Also published as: AT16974U1; MX2021008664A; HUE060760T2; EP3918619B1; WO2020154749A1; CN113348525B; US20220082036A1; US11649743B2; CN113348525A

Abstract

The invention relates to an electromagnetic actuator (1) having at least one electromagnetic actuator unit, the actuator unit comprising a coil (2) and a plunger (3), which plunger (3) is axially movable relative to the coil (2) via energization of the coil (2), and the actuator unit being arranged in a housing (4). In order to achieve a particularly simple design, the plunger (3) is arranged approximately coaxially with the coil (2) according to the invention.

Description

Electromagnetic actuator

The invention relates to an electromagnetic actuating device with at least one electromagnetic actuator unit, the actuator unit having a coil and a plunger, which plunger can be moved axially relative to the coil by energizing the coil, the actuator unit being arranged in a housing.

Various actuator units of the type mentioned at the outset have become known from the prior art. Such actuator units are used in particular for one

Camshaft adjustment device used. To enable camshaft adjustment in different directions, for example to be able to operate an engine with two or more different cam geometries

Adjustment devices with at least one actuator unit, preferably a plurality of actuator units which can be controlled independently of one another, are required, the actuator units being only a few millimeters apart. For this purpose, for example, a corresponding device has become known from DE 10 2007 028 600 B4, with which several plungers can be actuated in a limited space. The disadvantage of this device is that it can only be produced with great effort and therefore very expensive.

This is where the invention comes in. The object of the invention is to provide an actuating device of the type mentioned at the outset, which can be produced in a simpler and more cost-effective manner and yet meets requirements with regard to a required service life.

This object is achieved according to the invention by an actuating device of the type mentioned at the beginning, in which the plunger is arranged approximately coaxially with the coil.

In the context of the invention it was recognized that the production of the in the document

The device described in DE 10 2007 028 600 B4 is so complex because the tappets are arranged eccentrically to the coils, so that when the tappets are actuated, an eccentric force is applied to the tappets, which exerts a moment about a transverse axis of the usually approximately parallel tappets, which is perpendicular to a longitudinal axis of the plunger. This moment must go through a special elaborate guidance of the plunger must be taken into account to prevent the plunger from tipping over.

After the actuator unit is arranged approximately centrally to the coil in the actuating device according to the invention, so that a longitudinal or central axis of the coil coincides approximately with a longitudinal axis of the plunger assigned to the coil and the plunger is approximately coaxial with the coil, a corresponding moment becomes here around a transverse axis, that is to say around an axis perpendicular to the longitudinal axis, avoided in a simple manner, so that an expensive ram guide can be dispensed with. A lower load is thus achieved with the construction according to the invention, which is why a long service life can be ensured despite the simpler storage. Although the

Actuating device according to the invention can basically be designed with a single or any number of actuator units, it is particularly advantageous if exactly two actuator units are arranged in one actuating device in order to achieve a compact design. It goes without saying that in the case of an embodiment with a plurality of actuator units, each actuator unit is generally designed according to the invention.

For use of the actuator for cam adjustment in one

It is particularly favorable for an internal combustion engine if at least two actuator units are provided, the tappets in all the actuator units being arranged approximately coaxially with the coils, all actuator units preferably being in one

common housing are arranged. This allows a sleeve on a

Axial camshaft can be easily moved. Because of this construction, a particularly small distance between the tappets is possible with a simple and inexpensive construction.

It is favorable if, in the case of an actuating device with a plurality of actuator units, preferably each, plunger from an end position close to the core into a distance from the core

End position is movable, with the plunger abutting stops in the end positions. As a result, movements of the plungers are easily predefined with high accuracy. Usually the stops are made of metallic components,

in particular made of a magnetizable material. Normally, the setting device is designed as a bistable setting device, so that the plunger or plungers remain stable in the end positions when the coils are de-energized.

It is preferably provided that, in the case of an actuating device with several

Actuator units are preferably arranged on each, plunger a permanent magnet. This ensures that the plunger sticks independently in the end positions and thus provides a bistable device in a simple manner.

A particularly simple construction results if the coil, preferably in the case of an actuating device with several actuator units, is arranged around a core, the permanent magnet being magnetically separated from the core in the axial direction only by an air gap. No further device, in particular no metallic or magnetizable device such as an anchor element, is thus provided between the permanent magnet and the core. The core is usually made of a magnetically very good flux-conducting material, for example a leaded soft automatic steel.

It is preferably provided that, in the case of an actuating device with several

Actuator units, preferably an anchor element, in particular an anchor plate, are arranged on each tappet. The anchor element, which is usually made of a magnetizable metal, is usually rigidly connected to the plunger,

For example, by means of a laser weld seam and by energizing the coil via the resulting magnetic field, so that a force can be applied to the plunger by energizing the coil to electromagnetically move the plunger. As a rule, the plunger and the coil are arranged in a metallic jacket, via which a magnetic circuit can be closed, so that a magnetic flux starting from the coil via the core, the armature plate and the jacket is possible with low magnetic resistance.

This is usually the case with an actuating device with a plurality of actuator units

preferably each, plunger freely rotatable about the longitudinal axis in the adjusting device. This minimizes wear on the tappets, especially since they can roll on sleeves with which the tappets interact when the camshaft is adjusted. It has proven useful that a permanent magnet and an armature element are arranged on the tappet, preferably on each tappet in the case of an actuating device with a plurality of actuator units, the armature element projecting beyond the permanent magnet in a plane perpendicular to a longitudinal axis of the actuator unit. A magnetic circuit can then close with a particularly low magnetic resistance from the coil via the armature element and a jacket, so that the plungers can be actuated efficiently via the coils.

Advantageously, the tappet, in the case of an actuating device with a plurality of actuator units, preferably each, is connected indirectly or directly via a spring to the coil assigned to the tappet. This can be used in conjunction with the permanent magnet

Equilibrium of forces from magnetic force and spring force can be achieved, a resulting force or total force can be influenced with little effort by additional energization of the coil or a direction of the total force can be reversed by energizing the coil in order to actuate the actuator unit. The coil can, for example, be designed so that when a predefined one is applied

Voltage, in particular a voltage of an actuation voltage available in a motor vehicle, for example 12 volts, results in a corresponding magnetic field. The spring can be supported, for example, on the core or a yoke disk arranged behind the core. Furthermore, a spring can reduce the speed of the tappet during a movement against the stroke direction before the tappet strikes a stop on the core side. This reduces wear on the stop. This is particularly advantageous when the stop is formed by a core consisting of a soft, easily magnetizable material and a contact area between the plunger and the core is small in order to avoid sticking of the plunger to the core, in particular due to an oil film on the contact surface . Thus, by using the spring between the plunger and the core, a stop device made of a hard material can be dispensed with, which ensures a particularly simple construction.

Furthermore, when using a spring between the plunger and the coil, a particularly favorable course of a force acting on the plunger can be achieved over a stroke, so that an anchor element, in particular one arranged on the plunger magnetically conductive anchor plate, is not required to achieve a movement of the plunger between the end positions with a low energy input.

It is advantageous if the spring, the armature element, the permanent magnet and the coil are designed and matched to one another in such a way that when the coil is de-energized, a total force of spring force and magnetic force results, which the plunger from a predefined minimum distance from a core position close to the core, especially when the plunger is at a distance of less than 1 mm from the end position near the core, into the end position near the core. This ensures a stable position of the plunger in the end position close to the core in a simple manner when the coil is de-energized.

It is preferably provided that the spring, the armature element, the permanent magnet and the coil are designed and matched to one another in such a way that when the coil is energized, a total force of spring force and magnetic force results, which moves the plunger in an end position close to the core into an end position remote from the core . By energizing the coil, a total force acting on the armature element or the plunger from spring force, force of the permanent magnet and the magnetic force resulting from the magnetic flux when the coil is energized can be reached on the plunger, which pushes the plunger away from the end position close to the core to operate the actuator or actuator. As a rule, the spring force acts on the plunger located in the end position near the core in a stroke direction which points from the end position near the core to the end position remote from the core, while the force of the permanent magnet usually pulls the plunger near the end position close to the core and thus against the end position close to the core Stroke direction is aligned. The magnetic force on the armature element resulting from the magnetic flow through the coil when the coil is energized is generally also oriented in the stroke direction.

Usually, the adjusting device is designed in such a way that the plunger is moved away from the end position close to the core by the spring and the force caused by the magnetic flooding on the anchor element until the plunger passes through the

Permanent magnet is pulled into an end position remote from the core. As a rule, the plunger can be pulled by the permanent magnet from a distance less than 1 mm from the end position remote from the core to the end position remote from the core. Are preferred both in the end position close to the core and in the end position remote from the core

magnetizable or interacting with the permanent magnet arranged devices so that the plunger is pulled into the respective end position by the permanent magnet located in a proximity of the respective end position.

It is advantageously provided that the spring, the armature element, the permanent magnet and the coil are designed and matched to one another in such a way that a plunger located in an end position remote from the core remains in the end position remote from the core regardless of energization of the coil and only by an additional, in particular force applied to the plunger, force is movable from the end position remote from the core.

The plunger preferably adheres by means of the permanent magnet in the end position remote from the core, usually to a metallic component, in particular a plate. Moving the plunger back from the end position remote from the core is therefore only possible by actively moving the plunger, for example by a

Sleeve with cam track can be done on a camshaft. As a result, a bistable actuating device is achieved in a simple manner, which is stable when the coil is de-energized both in the end position near the core and in the end position remote from the core. Usually, the sleeves with which the tappets cooperate in camshaft adjustment devices have a groove following a curved path with a depth that can be varied over a circumference, so that the tappet can be moved back from the end position remote from the core by rotation of the sleeve or rotation of the camshaft.

It has proven useful that on the at least one, in the case of an actuating device with a plurality of actuator units, preferably on each actuator unit, a stop device,

in particular, an approximately hemispherical stop device at the end, preferably a ball or a pin, is provided, so that the plunger associated with the respective actuator unit rests against the stop device in an end position close to the core. By means of a stop close to the core, a end position of the plunger close to the core can be determined in a simple manner with high accuracy. The plunger is usually designed at a core-side end in such a way that a point-like contact surface is obtained when it comes into contact with the stop device.

For example, the plunger can have a flat point at a core-side end or a contact surface can run perpendicular to a longitudinal axis of the plunger, so that the contact surface is designed as a circular disk, for example, in the case of a cylindrical shape of the plunger. Through a punctiform contact surface, which is then approximately hemispherical in contact with a ball or at the end

trained pin results, an end position of the plunger can be defined particularly easily and at the same time with high accuracy. Corresponding balls and pens are mass products and therefore available in high quality at low cost.

The stop device can in principle be connected to the core in any way, in particular rigidly, for example pressed into the core or fixed in a component rigidly connected to the core, in particular a yoke disk. In order to minimize wear, however, the stop device can also be connected directly or indirectly to the coil of the respective actuator unit via a spring. An indirect connection can be made, for example, by the stop device via the spring with an end of the core on a plunger side

Opposite end of the core arranged yoke plate is connected, which is rigidly connected to the core and thus also to the coil. Furthermore, the spring can be connected to a core assigned to the respective actuator unit or to a component rigidly connected to the core, such as the yoke disk. In this embodiment, the tappet initially contacts the end connected to the core via the spring when moving from the end position remote from the core opposite to the stroke direction

Stop device, after which the stop device is moved with the plunger until the stop device hits the core or a component connected to the core, in particular a component rigidly connected to the core, preferably on a stop plate arranged in the core or a yoke disk connected to the core.

It is expedient if the stop device rests on a yoke disk connected to a core of the actuator unit, in particular is fixed in the yoke disk. Mechanical stress on the core can thus be minimized in a simple manner. Usually, the yoke disk on which the stop device rests is arranged on a rear side of the core, which is a front side of the core, on which the The plunger is positioned and which can also be referred to as the plunger-side end of the core.

It is preferably provided that the stop device is arranged in a through hole arranged in the core and preferably projects beyond the core on both sides along a longitudinal axis. If the stop device is supported on a component rigidly connected to the core and the coil, such as the yoke disk, which is arranged on a side of the core opposite the plunger in the direction of the longitudinal axis, a mechanical load on the core when the plunger stops on the Stop device be avoided entirely, so that a particularly long service life is achieved. In order to enable the plunger to come into contact with the stop device, the core then usually has a through hole into which the

The stop device and / or the plunger protrude when the plunger is in an end position close to the core. To minimize the moving masses, it is advantageous if the stop device, which is usually rigidly connected to the coil, is arranged entirely in the through hole in the core and projects through the core, but without the core being connected to the stop device in such a way that forces are transmitted in the direction of the longitudinal axis between the stop device and the core, so that the stop device projects beyond the core on both sides in the direction of the longitudinal axis. It has thus surprisingly been found that when a

Through hole in the core, a service life of the device can be increased because the stop device is no longer supported on the core, which is usually made of a soft material, but on one behind the core

arranged component can support, whereby the core is not stressed.

To ensure a highly precise end position of the ram even after a long period of use

To be able to ensure, it is preferably provided that the stop device has a higher hardness than a core assigned to the actuator unit. The core generally has favorable magnetic properties in order to obtain the lowest possible resistance of a magnetic circuit, by means of which the plunger is held by a

Current supply to the coil can be actuated. The stop device, however, can

for example made of a material such as 100Cr6. A predefined tappet movement can be achieved in a simple manner if a tappet guide, in which the tappet is slidably mounted, is provided for the tappet associated with an actuator with a plurality of actuator units, preferably each. A total force on the tappet resulting from spring force and magnetic force thus causes a movement along the tappet guide, depending on the direction of the total force. The plunger guide is preferably made of a metal. In the case of an actuating device with a plurality of actuator units, it can be provided that a plurality of tappet guides are arranged in a common component and are formed, for example, by cylindrical bores in a guide body.

If at least two actuator units are provided, however, it is particularly advantageous if each tappet is slidably mounted in a separate tappet guide, the tappet guides being movable relative to one another. This enables a particularly simple connection to a device on which the adjusting device acts, in particular to a motor, especially since positional tolerances at a mechanical interface to the device, in particular at mounting bores on the motor, in which the tappets engage, are compensated for by the movability of the tappet guides relative to one another can be. The plunger guides are preferably also movable relative to the coils or the housing in which housing the coils are arranged. It goes without saying that a minimum mobility of a few degrees or a few millimeters can be sufficient to compensate for positional tolerances.

In terms of design, this can be achieved, for example, if a tappet guide is provided for each tappet in the case of a plurality of tappets and the tappet guides are arranged in separate guide bodies, the guide bodies being movable relative to one another. This can be implemented, for example, in that the separate guide bodies are movably connected to the housing or a component of the actuating device that is rigidly connected to the coil. A correspondingly movable connection of the tappet guides to the housing can be achieved in a simple manner, for example, by means of a guide body connected to the housing by means of a clearance fit or to a component rigidly connected to the housing.

The ram guide can be in the guide body, for example, by a

Through hole are formed. This makes it particularly easy to install Adjustment device to an engine or a cylinder head cover of an engine possible, especially since then deviations on the engine and / or on the adjustment device can be easily compensated for by the small mobility of the guide bodies relative to the housing due to the clearance fit. The guide bodies can then be designed, for example, as turned parts, which are simple and inexpensive to produce. With such a design, the actuating device is also easily scalable. Thus, with corresponding guide bodies, actuating devices with any number of actuator units can also be produced in a simple manner, wherein positional deviations from mounting bores on a motor can be compensated for at the same time.

Usually, the adjusting device on a cylinder head cover

Internal combustion engine attached and engage the plunger accordingly

provided recesses or bores in the cylinder head cover or in the engine, through which recesses or bores the plunger with the on the

Camshaft arranged sleeves interact. By in separate

Tappet guides arranged in guide bodies are thus a simple way of compensating for tolerances between the recesses or bores.

The plungers are usually designed with an approximately cylindrical outer contour. Corresponding to this outer contour, the guides are preferably also approximately cylindrical and the guides have a diameter which corresponds to a maximum diameter of the tappets.

In order to achieve particularly low wear, it is favorable if the tappets have a central taper, which is positioned in the tappet guide in every possible tappet position between an end position of the tappet close to the core and an end position of the tappet remote from the core. The actuator is usually on one

Camshaft arranged in an engine, and thus in an oil mist. To the

Taper can then collect oil, which provides good lubrication of a contact surface between the plunger and the guide.

A particularly cost-effective construction can be achieved if a core arranged in the coil has an approximately cylindrical outer contour, with a maximum Outer diameter of the core is less than or equal to an inner diameter of the coil. The core thus preferably has no outside shoulder or the like, so that it is easy to manufacture, for example from a cylindrical primary material.

To achieve a high degree of efficiency, it is expedient if a preferably plate-shaped component made of a magnetically conductive material, in particular a yoke disk, is arranged and connected to the core at a plunger end of the core and / or at an end of the core opposite the plunger end. which component projects beyond the core in a direction radial to the longitudinal axis. As a result, a low magnetic resistance between the core and the jacket can be achieved in spite of an inexpensive to produce core with a cylindrical outer contour which does not exceed an inner diameter of the coil. The magnetic circuit can then, for example, consist of the core, which is arranged on both ends of the core

Yoke disks and the jacket and the magnetically conductive parts of the plunger are formed in a cost-effective manner. The yoke disks are usually

annular and made of an easily magnetizable plate material, a material of the yoke plates usually being made of one material

distinguishes from which the core is formed. With such an embodiment, in which the core and the two yoke disks are formed by separate components, compared to an embodiment in which the core and the yoke disks are formed by a single component, manufacturing costs can be reduced.

The actuating device according to the invention can in principle be used for any purpose. The advantages of the invention are particularly good

Actuating device can be used if this in a camshaft adjusting device for adjusting an axially movable sleeve on a camshaft in one

Internal combustion engine is used with an electromagnetic actuator.

Further features, advantages and expressions of the invention result from the exemplary embodiment shown below. In the drawings, to which reference is made, show:

Figure 1 shows an actuating device according to the invention in a sectional view. FIG. 2 shows a diagram from which forces acting on a plunger can be extracted over a stroke;

3 and 4 further embodiments of an actuating device according to the invention in a sectional view.

1 shows a sectional illustration of an actuating device 1 according to the invention. As can be seen, two actuator units are provided in a common housing 4 in the exemplary embodiment shown, each actuator unit having a coil 2, a core 7, around which the coil 2 is arranged, one along a longitudinal axis 17 extending plunger 3, a spring 10 which connects the plunger 3 to the core 7, a permanent magnet 6 and an anchor element formed by an anchor plate 9.

A magnetic circuit, via which the plunger 3 can be actuated by means of the coil 2, is closed via a jacket 15 in which the coil 2 is arranged and via which the coil 2 is magnetically connected to the armature element on the plunger 3.

As shown, to ensure a small distance between the plungers 3, it is expedient if the casing 15 is arranged to enclose both cores 7, but no casing 15 is positioned between the cores 7.

As can also be seen, the plungers 3 are each arranged coaxially to the longitudinal axes 17 of the coils 2 or centrally to the coils 2. The longitudinal axis 17 of the plunger 3 thus coincide with the longitudinal axis 17 of the plunger 3. As a result, the tappet 3 does not have a moment about an axis transverse to the longitudinal axis 17 when it is actuated by means of a magnetic force caused by the coils 2, which is why the tappet guide 12 can be of particularly simple design.

In order to be able to manufacture the adjusting device 1 particularly cost-effectively, the core 7 arranged in the coil 2 here has an essentially cylindrical outer contour, with a maximum outer diameter 28 of the core 7 being approximately a minimum

Corresponds to the inner diameter of the coil 2. It goes without saying that the coil 2 here is understood not only to be the windings themselves, but also a component which carries the windings and is located between the core 7 and the windings themselves. In order to nevertheless achieve a low magnetic resistance between the core 7 and the jacket 15, there are both at a plunger-side end of the core 7 and at an end of the core 7 opposite the plunger-side end

Yoke disks 27 are arranged, which protrude the core 7 radially to the longitudinal axis 17 and thus establish a magnetic connection between the core 7 and the jacket 15. The yoke disks 27 are made of an easily magnetizable plate material and have a circular cross section in a section perpendicular to the longitudinal axis 17.

The anchor plate 9 protrudes on each plunger 3 in a plane perpendicular to the longitudinal axis 17 or perpendicular to the image plane beyond the permanent magnets 6 of the respective plunger 3, so that a magnetic circuit can close via the anchor plate 9. The permanent magnets 6 are separated from the core 7 only by an air gap 8. An approximately hollow cylindrical protective sleeve 13 is arranged around each permanent magnet 6. A magnetic flux caused by the coil 2 and the magnetic circuit thus essentially runs through the core 7, the plunger 3, the armature plate 9 and the jacket 15.

As a result, a current can be applied to the armature element or the respective plunger 3 by energizing the coil 2, which forces the plunger 3 away from the core

End position 23 moved away.

Of the two actuator units shown in FIG. 1, the plunger 3 of the actuator unit shown on the left is in an end position 23 close to the core and the plunger 3 of the actuator unit shown on the right in FIG. 1 is in an end position 24 remote from the core. In the end position 23 close to the core, the plunger 3 is located on a stop device designed as a ball 5, which ball 5 is in turn positioned in the core 7, so that the core

End position 23 of the plunger 3 is defined in a simple and at the same time highly precise manner. The plunger 3 contact the ball 5 on an approximately circular, substantially flat, contact surface 16, so that there is a point-like contact.

In order to be able to ensure the exact position of the end position 23 close to the core over a long period of time or a desired service life of a motor in which the adjusting device 1 is used, the stop device is made of a material with a high hardness or a higher hardness than the core 7 . The tappets 3 are guided in tappet guides 12, which tappet guides 12 are formed by cylindrical bores in a guide body 18. The tappets 3 also have a cylindrical outer contour in some areas, which cooperates with the tappet guides 12, so that the tappet 3 only in the direction of the

Longitudinal axis 17 are translationally and rotatably movable about the longitudinal axis 17, but beyond that no movement of the plunger 3 relative to the housing 4 or the guide body 18 is possible.

As can also be seen, the tappets 3 in the tappet guides 12 have tapered portions 14 in which oil can collect in order to lubricate a movement of the tappets 3 in the guides and thus to minimize wear.

The plungers 3 are connected to the core 7 via the spring 10 and the permanent magnet 6 in such a way that the spring 10 acts on the plunger 3 in a lifting direction 25, that is to say from the end position 23 near the core in the direction of the end position 24 remote from the core parallel to the end position 24 Longitudinal axes 17, is exercised when the plunger 3 in the core

End position 23 are. The permanent magnets 6 close to the core

End position 23 a force counteracting the spring force 20 on the plunger 3

applied, which is greater in magnitude than the spring force 20, so that the plunger 3 are held in a currentless state of the coil 2 in the end position 23 close to the core by a total force of magnetic force and spring force 20. The total force thus acts against the stroke direction 25 when the coil 2 is de-energized.

In order to actuate an actuator unit and to move the corresponding plunger 3 from the end position 23 close to the core, an electrical voltage is applied to the coil 2 of this actuator unit, as a result of which a magnetic flux in the magnetic formed by the core 7, jacket 15, plunger 3 and armature plate 9 Circle causes a force on the plunger 3 in the stroke direction 25, so that the total force acting on the plunger 3 in

Direction of stroke 25 and the plunger 3 is moved from the end position 23 close to the core.

With the corresponding actuation, the plunger 3 is moved into the end position 24 remote from the core, in which the plunger 3 bears against a stop formed by a metallic plate 11. As shown, the longitudinal axes 17 of the two plungers 3 are approximately parallel and, when the adjusting device 1 is used, are usually spaced apart by less than 25 mm, in particular 6 mm to 15 mm. With the design of the adjusting device 1 according to the invention, a sufficient force for a camshaft adjustment can be provided despite the small distance.

2 schematically shows the forces acting on a tappet 3 of an actuator unit as a function of a stroke of the tappet 3 starting from the end position 23 close to the core in the stroke direction 25 up to an end position 24 of the tappet 3 remote from the core.

Shown are both a magnetic force, that is a force of the

Permanent magnet 6 and a magnetic force caused by energizing the coil 2 on the plunger 3, as well as a spring force 20 resulting from the spring 10, the magnetic force being shown in a solid line for a situation in which the coil 2 is not energized and in a broken line for a situation in which the coils 2 are energized. The solid line thus represents an electroless magnetic force 21, which is caused by the permanent magnet 6 alone, and the broken line represents the energized magnetic force 22, which is a total force from the force of the permanent magnet 6 and the magnetic force caused by the energization of the coil 2 on the Ram 3 forms. In the case of the spring force 20, a force in the stroke direction 25 is shown as a positive force, while the electroless magnetic force 21 and the energized one

Magnetic force 22 positive forces are aligned counter to the stroke direction 25. Values in the stroke direction 25 are shown on the ordinate of the diagram with respect to the spring force 20 and values against the stroke direction 25 in relation to the magnetic forces.

As can be seen, an electroless magnetic force 21 holding the plunger 3 in the end position 23 close to the core, that is to say with a stroke of 0 mm, is greater than the spring force 20 during this stroke. The plunger 3 is therefore when the coil 2 is de-energized by the

Permanent magnet e held in the end position 23 close to the core. As shown, the spring force 20 decreases over the stroke and approaches zero in the end position 24 of the plunger 3 remote from the core. This ensures that the spring 10 when the

Tappet 3 is never without a defined position between core 7 and tappet 3 or loose, which could lead to noise and wear. If the coil 2 is energized, the magnetic force holding the plunger 3 in the end position 23 close to the core is reduced below the amount of the spring force 20, so that the electroless magnetic force 21 acts, whereby the plunger 3 when the coil 2 is energized by the spring force 20 from the end position close to the core 23 is moved.

As can also be seen, the plunger 3 is pulled near the end position 24 remote from the core to the end position 24 remote from the core. This is done by a magnetic force caused by the permanent magnet 6, by which the plunger 3 is pulled to a plate 11 forming a stop in the end position 24 remote from the core.

The plunger 3 is thus position-stable both in the end position 23 close to the core and in the end position 24 remote from the core in a currentless state of the coil 2. In order to move the tappet 3 from the end position 24 remote from the core back into the end position 23 close to the core, the tappet 3 is, for example, at least to a minimum by means of a sleeve into which the tappet 3 engages in a camshaft adjusting device

Return position 19 moves against the stroke direction 25. From this minimal

Return position 19 is the tappet 3 pulling into the end position 23 near the core

Magnetic force of the permanent magnet 6 when the coil 2 is de-energized, i.e. the de-energized magnetic force 21 against the stroke direction 25, greater than the spring force 20 in the stroke direction 25, so that a resultant force acts against the stroke direction 25 on the plunger 3 and the plunger 3 from the minimum Return position 19 is pulled into the end position 23 close to the core when the coil 2 is de-energized.

3 shows a further actuating device 1 according to the invention, which is basically similar to the actuating device 1 shown in FIG. 1, but in contrast to the actuating device 1 shown in FIG. 1 has a pin 26 as a stop device. As shown, the stop device designed as a pin 26 is supported here on a yoke disk 27 arranged behind the core 7 or on a rear side of the core 7 opposite to a ram-side end of the core 7, so that the core 7 is not mechanically stressed when the ram 3 stops becomes. In order to be able to transmit a force from the tappet 3 to the yoke plate 27 when the tappet 3 stops, without mechanically stressing the core 7, a through hole is provided in the core 7 in this embodiment. In the embodiment shown, the pin 26 is positioned in the through hole and protrudes from the core 7 on both sides without however, to touch the core 7 or a yoke disk 27 arranged on a tappet-side end of the core 7 in a manner suitable for transmitting forces in the direction of the longitudinal axis 17. Furthermore, a spring 10 is also provided in this embodiment, which is also supported here on the yoke plate 27 and

Through hole penetrated in the core. Alternatively, the spring 10 could, of course, also be supported on the core 7, for example on a shoulder in the through hole in the core 7. This embodiment results in an increased service life because the core 7 is not mechanically loaded each time the plunger 3 strikes. The through hole can lead to a magnetic weakening 7 of the core 7 or to an increased magnetic resistance of the core 7, which are accepted in order to minimize the mechanical load.

FIG. 4 shows another actuating device 1 according to the invention, which is largely constructed analogously to that shown in FIG. In a departure from the adjusting device 1 shown in FIG. 3, the tappet guides 12 are here arranged in separate guide bodies 18 which are connected to the housing 4 via the plate 11. The

Guide bodies 18 are connected to the plate 11 with little mobility or with play, so that the actuating device 1 can be connected in a simple manner to a connection component of an engine, as a rule a cylinder head cover, even if manufacturing tolerances apply to both the engine and also with the

Actuating device 1 can be used in the most unfavorable manner or a mechanical interface on the motor has position and / or position deviations. Thus, the guide body 18 and thus an alignment of the longitudinal axes 17 of the plunger 3 by the movable connection of the guide body 18 to the housing 4 or to

Plate 11 can be easily adapted to the relevant circumstances. It is understood that the guide bodies 18 can then also be moved relative to one another

Longitudinal axes 17 of the plunger 3 may no longer be exactly parallel.

With an adjusting device 1 according to the invention, a bistable adjusting device 1 for camshaft adjustment is achieved in a particularly simple manner, which ensures particularly simple and therefore inexpensive guiding of the tappets 3.

Claims

Expectations

1. Electromagnetic actuator (1) with at least one electromagnetic actuator unit, the actuator unit having a coil (2) and a plunger (3), which plunger (3) by energizing the coil (2) relative to the coil (2) axially is movable, the actuator unit being arranged in a housing (4), characterized in that the plunger (3) is arranged approximately coaxially with the coil (2).

2. Electromagnetic actuator (1) according to claim 1, characterized

characterized in that at least two actuator units are provided, the tappets (3) being arranged approximately coaxially with the coils (2) in all the actuator units, all actuator units preferably being arranged in a common housing (4).

3. Electromagnetic actuator (1) according to claim 1 or 2, characterized in that the plunger (3) from an end position close to the core (23) in an end position remote from the core (24) is movable, the plunger (3) in the

End positions (23, 24) each abut stops.

4. Electromagnetic actuator (1) according to claim 1 or 3, characterized in that a permanent magnet (6) is arranged on the plunger (3).

5. Electromagnetic actuator (1) according to claim 4, characterized

characterized in that the coil (2) is arranged around a core (7), the

Permanent magnet (6) is magnetically separated from the core (7) in the axial direction only via an air gap (8).

6. Electromagnetic adjusting device (1) according to one of claims 1 to 5, characterized in that an anchor element, in particular an anchor plate (9), is arranged on the plunger (3).

7. Electromagnetic actuator (1) according to one of claims 1 to 6, characterized in that on the plunger (3) a permanent magnet (6) and a Anchor element are arranged, the anchor element projecting beyond the permanent magnet (6) in a plane perpendicular to a longitudinal axis (17) of the actuator unit.

8. Electromagnetic actuator (1) according to claim 7, characterized

characterized in that the plunger (3) is connected via a spring (10) directly or indirectly to the coil (2) assigned to the plunger (3).

9. Electromagnetic actuator (1) according to claim 8, characterized

characterized in that the spring (10), the armature element, the permanent magnet (6) and the coil (2) are designed and matched to one another in such a way that when the coil (2) is de-energized, a total force of spring force (20) and magnetic force results which pulls the plunger (3) from a predefined minimum distance from an end position (23) close to the core, in particular at a distance of the plunger (3) from the end position (23) close to the core of less than 1 mm, into the end position (23) close to the core.

10. Electromagnetic adjusting device (1) according to claim 8 or 9, characterized in that the spring (10), the armature element, the permanent magnet (6) and the coil (2) are designed and matched to one another such that at

Current supply to the coil (2) results in a total force of spring force (20) and magnetic force, which moves the plunger (3) located in an end position (23) close to the core into an end position (24) remote from the core.

11. Electromagnetic actuator (1) according to one of claims 8 to 10, characterized in that the spring (10), the anchor element, the

Permanent magnet (6) and the coil (2) are designed and matched to one another in such a way that a plunger (3) located in an end position (24) remote from the core remains in the end position (24) remote from the core regardless of energization of the coil (2) can only be moved from the end position (24) remote from the core by an additional, in particular form-fittingly applied to the tappet (3).

12. Electromagnetic adjusting device (1) according to one of claims 1 to 11, characterized in that on the at least one actuator unit

Stop device, in particular an approximately hemispherical end

Stop device, preferably a ball (5) or a pin (26), is provided, so that the tappet (3) assigned to the actuator unit rests against the stop device in an end position (23) close to the core.

13. Electromagnetic actuator (1) according to claim 11, characterized

characterized in that the stop device is connected directly or indirectly to the coil (2) of the respective actuator unit via a spring (10).

14. Electromagnetic actuator (1) according to claim 12 or 13, characterized in that the stop device on a with a core (7)

Actuator unit connected yoke plate (27), in particular is fixed in the yoke plate (27).

15. Electromagnetic actuator (1) according to claim 14, characterized

characterized in that the stop device is arranged in a core (7)

Through hole is arranged and preferably the core (7) along a

Longitudinal axis (17) protrudes on both sides.

16. Electromagnetic adjusting device (1) according to one of claims 1 to 15, characterized in that a plunger guide (12) is provided in association with the plunger (3), in which the plunger (3) is slidably mounted.

17. Electromagnetic actuator (1) according to claim 16, characterized

characterized in that at least two actuator units are provided, each plunger (3) being slidably mounted in a separate plunger guide (12), the

Ram guides (12) are movable relative to each other.

18. Electromagnetic actuator (1) according to claim 16 or 17, characterized in that the tappet guides (12) in separate guide bodies

are arranged, the guide bodies being movable relative to one another.

19. Electromagnetic actuator (1) according to claim 18, characterized

characterized in that the plungers (3) have a central taper (14) which, in each possible plunger position, between an end position (23) close to the core Tappet (3) and an end position (24) of the tappet (3) remote from the core is positioned in the tappet guide (12).

20. Electromagnetic adjusting device (1) according to one of claims 1 to 19, characterized in that a core (7) arranged in the coil (2) is a

having a cylindrical outer contour, a maximum outer diameter (28) of the core (7) being smaller than or equal to an inner diameter of the coil (2).

21. Electromagnetic actuator (1) according to claim 20, characterized

characterized in that a preferably plate-shaped component made of a magnetically conductive material, in particular a yoke washer (27), is arranged on a plunger-side end of the core (7) and / or on an end of the core (7) opposite the plunger-side end and connected to the core ( 7), which component projects beyond the core (7) in a direction radially to the longitudinal axis (17).

22. Camshaft adjusting device for adjusting an axially movable sleeve on a camshaft in an internal combustion engine with an electromagnetic

Actuating device (1), characterized in that the electromagnetic

Actuating device (1) is designed according to one of claims 1 to 21.