DE10044789A1 - Gas exchange valve control for valve-controlled internal combustion engine has rotor with concentric permanently magnetic rings and stator of magnetically soft material - Google Patents

Abstract

The valve control has a hollow cylindrical rotor (16) and a stator (18). The rotor has permanently magnetic rings (30) one above the other. The stator consists at least partly of a magnetically soft material and has at least one tooth (22) facing the rotor. The stator has interior and exterior magnetically conductive regions, with the rotor rings between them.

Description

Background of the Invention

The present invention relates to a drive device a gas exchange valve for a valve-controlled Ver brennungsmotor. In particular, the invention relates to a Gas exchange valve, in which the reciprocating movement of the Ven tilliedes not caused and controlled by a camshaft is heard. Rather, in the gas exchange according to the invention selventil the valve member actuated electrically.

Background of the Invention

Such electrically operated valve arrangements are in the most diverse configurations in the state of the tech not known.

DE 195 18 056 A1 describes a gas valve control a gas exchange valve known by an Elektroma gnetanordnung is operated. Here is a special re configuration of the pole leg of the electromagnet arrangement a signal related to the movement of the armature in the drive line of the electromagnet assembly. This signal can be evaluated to any anchor positions without recognizing additional sensors. A big one ßes problem when using an electromagnet assembly Operation of the valve is the high level of noise when reaching the respective end positions, the abrupt Braking when reaching the end positions and the requ such high holding currents.

The same applies to variously proposed differences tial-electromagnet arrangements that are necessary to achieve the requ thrust of about 300-400 N for car burning targeted motors with increasing currents  become. This leads to the loading of a spring arrangement Valve first oscillates before one on the Valve stem arranged iron plate on the anchor of the elec Tromagnetanordnung is applied, so that a much smaller Holding current is required. However, the ma Maximum engine speed significantly limited. The startup time at the start is relatively high, because it is necessary takes a long time before the venti l arrangement has swung into its desired position.

From JP-A-3-92518 is a drive device for a Valve arrangement in internal combustion engines is known, in which the Stator made up of two approximately semi-cylindrical shells is that both in the circumferential direction and in the longitudinal direction teeth of each shell split teeth facing the rotor exhibit. The individual teeth of each shell are each surrounded by a winding, the central longitudinal axis in radi all direction. This results in a radial Directional magnetic flux that starts from each one of the variety of teeth through the air gap between stand and runner, into which runner flows.

A matching design of the stand, the stator coils and the rotor of a drive device for a valve arrangement in internal combustion engines is in the US 5,129,369. Here too are in radial and teeth of the stand divided in tangential direction Weil surrounded by a winding, the central longitudinal axis in radial direction.

EP 0 485 231 A1 also shows a similar type of Ge design of the stator, the stator coils and the rotor a drive device for a valve arrangement in Ver combustion engines. Again are in radial and tangentia Teeth of the stand divided in the direction of each egg Surround radially oriented winding.  

These arrangements are very complex to manufacture, because the assembly of the windings around the individual teeth is difficult to do. In addition, it is with the Sem structure achievable pole pitch relatively large.

From WO 98/55741 a valve arrangement for a ven valve-controlled internal combustion engine known, with an elek trical traveling field motor as an actuator for a valve member, one runner coupled to a valve member and egg has a stand. The stand is made of sheet metal builds, the area perpendicular to the direction of movement of the Läu he is oriented. The stand has the synchronous or Asynchronous runners trained runners facing teeth each a closed cylinder facing the rotor have surface area. Between two neighboring counts NEN of the stator winding chambers are formed in which one each oriented parallel to the surface of the sheets Winding is arranged.

Further documents without any claim to completeness, which show the technical background for the invention, are:
DE 33 07 070 A1, DE 35 00 530 A1, EP 244 878 B1, WO 90/07635, US 4,829,947, EP 377 244 B1, EP 347 211 B1, EP 390 519 B1, EP 328 194 B1, EP 377 251 B1, EP 312 216 B1, US 4,967,702, US 3,853,102, US 4,829,947, US 4,915,015, WO 90/07637, EP 244 878 B1, EP 328 195 A2.

Problem underlying the invention

All concepts in the documents mentioned above have in common that with those in the prior art Known technology arrangements also for gas exchange valves le stroke, thrust and dy required in internal combustion engines namik with a sufficiently compact structure and reliability not achieved for large-scale use in automotive engines become. In addition, there are known arrangements in the manufacture very expensive. In addition, these arrangements also not for use in high-speed (high-speed)  Internal combustion engines optimized because none of this arrangement is optimized with regard to the moving masses.

Solution according to the invention

To overcome these disadvantages, the invention teaches an Driving device of a gas exchange valve for a valve controlled internal combustion engine, with an electric line armotor as an actuator for a valve member, which by the Features of claim 1 is defined.

Structure and developments of the solution according to the invention

According to the stand is made of a soft magnetic Material built up and has teeth facing the runner. There is one between two adjacent teeth of the stand Winding chamber is formed in which a winding is arranged is not. The runner has rings made of permanent magnetic mate rial on. These magnetic rings are concentric about arranged one another and their magnetic orientation is designed so that in a predetermined position of the Läu fers two teeth of the stator, which has a winding between record each other with a magnetic ring aligned magnetic orientation.

The stator is required to form an external rotor motor at least partly from the runner - from each other by one Separated air gap - surrounded. In an analogous manner Formation of an internal rotor motor at least partially wisely surrounded by the stand. It is according to the invention also possible, the stand by stacked Permanent magnet disks form while the rotor is one Has winding chamber, which by appropriate Weichma magnetic ring discs is limited.

These arrangements according to the invention allow a very small pole pitch of the linear motor. So that's a very ho he force density can be realized.  

A major advantage of the gas exchange according to the invention valve is that practically only the magnetic effective components (the permanent magnets) to the inert mass of the runner, while all other parts of Mo. tors (coils, magnetic yoke, etc.) to the stator are ordered. This can be a particularly high ratio from inertia exerted by the engine to inert mass aims to be. In addition, the gas exchange according to the invention valve excellently suited, in fast running ver internal combustion engine to be used. In particular, the closer the valve member to the end positions (Open or closed position of the gas exchange valve) the speed of the runner with high acceleration Changes are made so that the impact of the valve member which takes place in the valve seat at minimum speed, while the valve member with very high speed is moved. This allows a very noisy and low-wear operation of the gas exchange valves.

Since it is the gas exchange valve according to the invention single-phase, individually controllable series connections Motors can do that by the linear motor as a whole generated force exactly along the stroke of the valve member can be adjusted to the required force. because with it is not necessary to lift the valve member kinetic energy so that this takes its final position. This means that considerably less energy is required to actuate the valve member Lich than in those known from the prior art Arrangements. This also means a significantly lower Ge noise and less wear.

By arranging the stator winding, it is possible to to keep vibrations acting on the winding low, causing vibration of the winding or friction of the winding are small on the wall of the winding chamber. So that is it is possible with minimal insulation material or stripping material of the winding chamber. This too  contributes to the compactness and reliability of the overall arrangement at. This also results in a high power density even with small gas exchange valves because the fill factor of the Winding chamber (winding volume in the winding chamber based on the total volume of the winding chamber) high is.

The invention enables the construction of a drive device device of a gas exchange valve, in which the at least one Winding over its entire extension for effective Force generation in the linear motor contributes. This means, that the winding has no end windings, as is the case with conventional motors is the case. The reason for this is, that the winding is completely between the end faces of the Stand is included in the winding chambers and the wick tion neither in the axial direction nor in the radial direction protrudes beyond the teeth of the stand.

So that the valve assembly according to the invention has an Ak tuator, which is considerable compared to a conventional motor less copper (winding mass) to produce a ver has the same force / displacement profile.

The stand preferably has a tape wrap made of soft magnetic sheet metal tape, with on the end faces of the Tape wraps each have a soft magnetic molded body preferably made of pressed and / or sintered metal powder is arranged to form the teeth.

The tape roll and the shaped bodies have at least one Recess in which a sensor for path detection, for Example in the form of an interferometer or one with the Valve member connected iron rod with elevations and ver wells that are scanned by a Hall probe. This is particularly advantageous because with the inventions actuator according to the invention also partial strokes (i.e. intermediate position between open and closed) of the valve arrangement  possible are. This partial stroke can be detected by the sensor or controlled.

Realized with the embodiments according to the invention This is one of the reasons for the high power density available that the teeth or those opposite them Chen permanent magnets in relation to the axial extension the winding chamber are so short that at least two more permanent magnets (each with different magnetic orientation).

According to the invention is in a preferred embodiment the runner at least partially by a magnetic Inference body surrounded. Especially when using more It is the side-by-side gas exchange valves advantageous, on the one hand little with each gas exchange valve At least two winding chambers with teeth, windings in the stand to provide the and corresponding permanent magnets in the rotor, with the windings in the adjacent gas exchange valves are driven in opposite directions so that the magnetic Flows through the magnetic yoke body as possible have little stray flux. So that the volume - and the weight - the magnetic yoke body low being held. In addition, the ver loss services. An important aspect is that the magnetic yoke body has the shape of an im Cross section has approximately rectangular profile tube, at on which two opposite walls have openings through which the inner part of the stator (coil arrangement openings) and the runner protrude. This arrangement mini lubricates the stray fluxes and in particular also allows one very efficient assembly of several side by side such gas exchange valves, wherein - corresponding elec trical control required - adjacent gas changes valve drives the magnetic inference at least to Can use part alternately. The mass (and the volume) of the magnetic yoke body is minimized become.  

Finally, the invention relates to internal combustion voltage engine with at least one combustion cylinder, with at least one drive device for inlet or outlet valves with one or more of the above features.

The following properties result from the configuration of the gas exchange valve according to the invention:

• - high drive dynamics with low power consumption.
• - A spring arrangement to compensate for moving Mas The forces created are not required to a mass of the valve member of about 30-70 grams, one Valve stroke of about 5-10 mm and a speed of a four cylinder internal combustion engine of at least about 6000 rpm an end position change (from open to closed or vice versa) of the valve member of less than 1.5 millise customers with an average power consumption of more than two complete crankshaft revolutions of less than 100 To realize watts.
• - Are in the respective end positions of the valve member only small holding currents are required around the valve member si cher in the respective position.
• - Since there is no spring arrangement (see above) there is no need for the valve to settle otherwise member. This reduces the duration of the adjustment process.
• - By the actuator according to the invention, the valve member practically from any current position precisely in any position. This applies in particular to the end positions that are very precise from the valve member can be driven. So that can match - with one the electronic control of the winding (s) on hit the valve member in its valve seat with less than 40 mm / sec. This keeps the ver wear and the noise of the valve arrangement in the Operation very low.
• - The valve member can with respect to its valve seat Axis of movement can be rotatably added, so that a selective  Wear of the valve member or the valve seat is prevented.
• - Due to the high power density of the invention can order the transverse dimensions (diameter) of the gas shuttle valve with the necessary performance data very much be kept small. This allows the use in compact car engines.

Other features, characteristics, advantages and possible ab Changes will be made for a specialist using the following the description clearly, in the on the attached drawing reference is made.

Brief description of the drawings

In Fig. 1, a drive device of a Gaswechselven valve for a valve-controlled internal combustion engine is schematically illustrated in longitudinal section.

In Fig. 2, a second embodiment of a drive device of a gas exchange valve for a valve-controlled internal combustion engine is schematically partially illustrated in longitudinal section.

In Fig. 3, a third embodiment of a drive device of a gas exchange valve for a valve-controlled internal combustion engine is schematically partially illustrated in longitudinal section.

Description of preferred embodiments of the invention

Identify corresponding reference numerals in the three figures draw the same or equivalent parts and are not explained several times.

An electric linear motor 10 is used in the valve arrangement according to the invention as an actuator for a valve member 12 , the associated valve seat of which is not further illustrated. The linear motor 10 has a rotor 16 coupled to the valve member 12 via a rod 14 and a stator 18 .

The stand 18 has as a core a hollow cylindrical band winding 18 a made of a soft magnetic sheet metal strip, preferably made of iron-cobalt sheet metal, the surface of which is oriented parallel to the axis of movement B of the rotor 16 . At the end faces of the tape roll 18 a, a soft magnetic molded body 18 b, 18 c made of sintered egg sen metal powder is arranged, which protrude beyond the tape roll 18 a in a radial extent. The shaped bodies 18 b, 18 c of the stand 18 form teeth 22 facing the rotor 16 with a closed lateral surface on their circumference. In the vorlie example with circular form bodies 18 b, 18 c in plan view, the individual teeth 22 have a circular cylindrical outer surface. However, it is also possible to use oval shaped bodies 18 b, 18 c or shaped bodies 18 b, 18 c with a polygonal shape to construct the stand 18 .

The hollow cylindrical tape roll 18 a and the two circular shaped bodies 18 b, 18 c in plan view form a winding chamber 26 which is open to the outside and in which a stator winding 24 is arranged which is concentric with the central longitudinal axis of the stator 18 . The stator winding 24 is designed to achieve the highest possible fill factor as a copper coil. The type of connection of the individual windings 24 or their time-controlled application of electrical current is dependent on the desired type of motor (single or multi-phase motor).

In the middle, the stand 18 has a recess 30 in which a rod 34 with a tooth profile etched on its peripheral surface, which is scanned with a Hall probe 36 . The lower end (in the figure) of the rod 34 is rigidly coupled to the valve member 12 or the rod 14 , so that the Hall probe 36 can detect a movement of the rod 34 in the direction of movement B.

Since each winding 24 is arranged over its entire extent in the winding chamber 26 , it also contributes over its entire length to the effective generation of force in the linear motor.

In the arrangement shown, the rotor 16 is a hollow cylinder which has rings 20 made of permanent magnetic material (for example samarium-cobalt). The individual rings 20 are arranged concentrically one above the other, the magnetic orientation of the rings (indicated by the center of the stator or away from it arrows in each ring) is radially oriented and designed so that in a predetermined position of the rotor 16 two teeth 22 of a stand 18 , each aligned with a ring 20 with opposite magnetic orientation. In this case, in particular sondere in the embodiment shown in FIG. 1 with three or more superposed stator coils, a magnet ring with a tooth of a first stator (for a game is the mean) are in alignment, while the second Magne tring with a tooth of a second stand (for example, of the lower) is aligned. However, it is also possible for the two magnetic rings to be aligned with the two teeth of a stand.

In the embodiments shown in all three figures, the rotor 16 is constructed from permanent magnet rings, with a magnetically ineffective spacer in the form of hollow cylinders 16 a, for example made of carbon fiber reinforced, between two permanent magnet rings of opposite magnetic orientation, which belong to a stator coil Plastic is arranged. The adjacent permanent magnet rings and the magnetically ineffective hollow cylinders are firmly connected. In other words, there are no magnetic flux-conducting parts in the moving part of the motor (the rotor), but only permanent magnets, which are always optimally arranged in the magnetic field. This arrangement also has the advantage of saving weight. Unless radially oriented ring discs made of permanent magnetic material cannot produce the sufficient magnetic field strength, it is also possible according to the invention to assemble ring disc segments from permanent magnets so that a radial (from the inside out or vice versa) directed magnetic field is created.

As a magnetic yoke as part of the stator, a magnetically conductive tube 32 with a rectangular cross section is seen, which has recesses 32 a, 32 b in two opposite walls through which the rotor 16 and the stator protrude. The walls of the tube 32 have such a material thickness and such a distance from one another that they are aligned with two teeth 22 of a stand 18 .

Two adjacent stands 18 of a Gaswechselven valve are firmly connected to one another by an aluminum rail 40 acting as a spacer and eddy current shielding. At the end facing away from the valve member 12 , the rotor 16 is coupled to a sensor 36 for detecting the path of the rotor 16 in the direction of movement B.

In the embodiment shown in Fig. 1 three stands are arranged one above the other. Here, in the lightest embodiment of the rotor two magnetic rings can be arranged in the Ab from each other. However, at least four magnetic rings are preferably provided, with two magnetic rings (ie one magnetic ring pair) with opposite magnetic orientation either lying directly against one another or only having a small (axial) distance from one another. By defining the distance between the magnetic rings to each other or the distance between the magnetic ring pairs to each other, the stroke profile can be influenced who.

In the embodiment shown in FIG. 2, the stands are basically unchanged, but the axial distance between the tubes 32 is reduced in that the spacer 40 has a smaller height. Furthermore, the number of magnetic rings 20 is significantly reduced compared to the embodiment of FIG. 1, which means a significantly reduced moving mass. It should be mentioned that the only one magnetic ring per magnetic coil or stator pole pair represents the minimum number. In this arrangement, the direction of the magnetic flux is no longer relevant as long as the magnetic flux is oriented in the radial direction.

Another embodiment is shown in Fig. 3, in which the spacers 16 a are dimensioned so that the middle coil are assigned two magnets, while the upper and lower coil is assigned only one magnet.

Claims (10)

1. Drive device of a gas exchange valve for a valve-controlled internal combustion engine, with an electric linear motor ( 10 ) as an actuator for a valve member, the egg NEN with a valve member ( 12 ) to be coupled rotor ( 16 ) and a stator ( 18 ), wherein
the stator ( 18 ) is constructed from a soft magnetic material and has teeth ( 22 ) facing the rotor ( 18 ), and a winding chamber ( 26 ) is formed between two adjacent teeth ( 22 ) of the stator ( 18 ), in which a winding ( 24 ) is arranged, and
the rotor ( 16 ) has rings ( 20 ) made of permanent magnetic material, which are arranged concentrically one above the other, the magnetic orientation of the rings ( 20 ) being such that in a predetermined position of the rotor ( 16 ) at least one of the teeth ( 22 ) of a stand ( 18 ) aligned with a ring ( 20 ) made of permanent magnetic material, and wherein a magnetically ineffective spacer ( 16 a) is arranged between two rings made of permanent magnetic material. 2. Drive device of a gas exchange valve for a valve-controlled internal combustion engine according to claim 1, wherein the stator ( 18 ) has a tape roll ( 18 a) made of soft magnetic sheet metal strip. 3. Drive device of a gas exchange valve for a valve-controlled internal combustion engine according to claim 2, wherein a soft magnetic molded body ( 18 b, 18 c), preferably made of pressed and / or sintered metal powder, is arranged on the end faces of the tape roll ( 18 a). 4. Drive device of a gas exchange valve for a valve-controlled internal combustion engine according to claim 2 or 3, wherein the tape winding and the molded body have at least one recess ( 30 ) in which a displacement sensor ( 34 , 36 ) for detecting the stroke of the valve member ( 12 ) is received. 5. Drive device of a gas exchange valve for a valve-controlled internal combustion engine according to claim 1, wherein at least one winding ( 24 ) contributes over its entire extent to the effective force formation in the linear motor ( 10 ). 6. Drive device of a gas exchange valve for a valve-controlled internal combustion engine according to claim 1, wherein the teeth ( 22 ) or the permanent magnets opposite them ( 20 ) in relation to the axial extent of the winding chamber ( 26 ) are dimensioned such that at least two further permanent magnets ( 20 ) Find a place. 7. Drive device of a gas exchange valve for a valve-controlled internal combustion engine according to claim 1, wherein the rotor is at least partially surrounded by a magnetic yoke body ( 32 ). 8. Drive device of a gas exchange valve for a valve-controlled internal combustion engine according to claim 7, wherein the magnetic yoke body ( 32 ) is formed by a vorzugwei se rectangular in cross-section magnetically conductive tube, in which recesses ( 32 a, 32 b) are provided in two opposite walls , through which the rotor and the stand protrude, the walls having such a material thickness and such a distance from one another that they are in alignment with two teeth ( 22 ) of a stand ( 18 ). 9. Drive device of a gas exchange valve for one A valve-controlled internal combustion engine according to claim 1, wherein each magnetically ineffective spacer has two duration magnet rings at a predetermined distance from each other holds.   10. Internal combustion engine with at least one ver combustion cylinder with at least one valve arrangement the features of one or more of the preceding claims che.