WO2014095144A1 - Electromagnetic actuating apparatus - Google Patents

Abstract

The invention relates to an electromagnetic actuating apparatus having armature means (10, 12, 14, 16, 22) which can be driven relative to stationary coil means (34, 36; 34, 40) in response to current being applied to said coil means, it being possible to detect the movement (U_Switch) and/or actuating position of said armature means relative to stationary core means (29), which interact with the coil means, using detection means which are associated with the coil means, wherein the coil means have a first coil winding (34), which is designed to magnetically interact with the armature means by means of current being applied, and also have a second coil winding (36; 40), which is designed to generate a detection signal outside the time at which current is applied for the detection means, the first and the second coil winding forming a parallel circuit in order to form a two-terminal circuit, and the two-terminal circuit having associated electronic switching and/or blocking means (D1, D2) such that said switching and/or blocking means prevent shorting of the detection signal (U_Sensor) by means of the first coil winding when current is not applied.

Description

 Electromagnetic actuator

The present invention relates to an electromagnetic actuator according to the preamble of the main claim. Such a device is known from DE 20 2005 01 1 901 U1 of the Applicant.

The purpose of the generic technology is to provide a suitable in particular for adjusting the camshaft on a motor vehicle engine actuator whose anchor (plunger) position or movement is detected in a simple manner. In the generic technology for this purpose, the energized for driving the anchor means coil is additionally used in its de-energized state during this period, a voltage induced by the armature unit or its movement in the coil voltage tapped as a signal from the coil terminal and suitably subsequently by the detection means is evaluated. It is advantageously achieved by this measure that no additional sensors or detector units are required for the armature detection, which, in addition to corresponding component expenditure, would also require more extensive connection and line infrastructure.

However, the technology described in DE 20 2005 01 1 901 U1 proves to be in need of improvement in practical implementation, and in particular in connection with dynamically developed, rapidly switching actuators. For example, fast-rotating engines produce correspondingly short camshaft circulation times, which means that increasingly shorter shift times are required for electromagnetic actuators engaging in them; in particular the period between the beginning of the energization of the coil means and the Extending the anchor means (with its end-side engagement ram) in a stroke end position is to be made correspondingly short. This is achieved, inter alia, structurally in that the coil means provided with the energization for the purpose of the armature movement are increasingly low-resistance (and also have relatively lower inductances), which is made possible by corresponding wire cross-sections and winding or winding numbers of the winding wire used for the coil means. However, a disadvantage of such low-resistance coils is that the signal detected in the non-energized state ("throw-back signal") is significantly smaller and therefore harder to detect than in the conventional technology.

Object of the present invention is therefore to provide a generic electromagnetic actuator, which, for example by low-resistance, provided with low numbers of coils coil means is improved in their dynamic properties and has shortened switching times to improve so that nonetheless in the state of non-energization reliable detection the movement or setting position of the anchor means is detectable from a voltage applied to the coil means detection signal.

The object is achieved by the electromagnetic actuator with the features of the main claim; advantageous developments of the invention are described in the subclaims.

In accordance with the invention advantageously, the coil means are realized in the form of two separate, but to achieve a two-pole parallel coil windings, of which a first in the above, dynamically advantageous manner for driving the armature unit can be provided with the energization and, relative to the second coil winding, by appropriate design of the Spool wire and / or a reduced number of turns, low impedance is realized. In contrast, the second coil winding, designed relative to the first coil winding by appropriate design of the coil wire and / or an increased number of turns high or high resistance, as a sensor or detector winding and is used to generate the detection signal outside the energization (more precisely: the Bestromungszeit) evaluated ,

However, in order not to increase a line and Beschaltungsaufwand for realized in the form of two components or assemblies coil means, the first and the second coil winding is connected in parallel as a two-pole, such that each of the coil windings forms a branch, the respective branch ends together are connected and at these junctions externally (with the power source and the downstream detection means) are connected. The two-pole thus created makes it possible to use a connection or plug infrastructure that is already known for the generic technology, without the need for additional connections or lines; Especially in an automotive environment with corresponding resource constraints, this leads to considerable advantages in the practical realization.

Since the parallel connection according to the invention would generate the problem that in the non-energized state a detection signal of the armature movement generated by the (high-resistance) second coil winding would be short-circuited by the (low-resistance) first coil winding, electronic switching or blocking means are provided according to the invention for the two-pole, which, in particular by selectively blocking or interrupting the path associated with the first coil winding, prevents such a short-circuit effect. In fact, during energization, the first coil winding also generates one of the Ankerbewegung corresponding induction signal, but this is due to the significantly lower number of turns less than the detection signal of the second coil winding, so that corresponding equalizing currents flow, which then no longer give usable signal at the terminals of the two-pole.

In contrast, the parallel connection of the two coil windings during energization is much less problematic because, due to the higher-resistance configuration, only a negligible proportion of current of the energization signal would flow through the second coil winding.

While in the development of the invention, the blocking means may have almost any (electrical) switching means, in particular semiconductor-based implemented, it is favorable according to a preferred embodiment of the invention to realize the further education switching or blocking means as a diode, which in the first (low-resistance) coil winding associated branch of the parallel circuit is looped. This diode becomes effective when the second coil winding generates the detection signal (that is to say the induction voltage) in a polarity which is opposite to the polarity of the current supply. In such an embodiment of the second coil winding, the detection signal generated therein would then be represented by the diode associated with the first coil winding be blocked and can thus be tapped by the detection means on the dipole and subsequently evaluated.

On the one hand, it is advantageous to realize this reverse polarity (opposite current flow direction) in that the first and the second coil windings are wound in opposite directions relative to each other. Alternatively, in the same direction winding, a corresponding opposite contacting of the windings take place. In the constructional realization of the invention, there are numerous possibilities for developing the first and the second coil winding - wound or contacted in opposite directions - it being preferred to provide both coil windings adjacent to one another, more preferably on a common coil support. Again according to further developments, this common coil carrier can advantageously be wound along an axial direction of the adjusting device, ie parallel to a direction of movement of the armature unit, first with a coil or winding section realizing the first coil winding, then with a coil section implementing the second coil winding, or else it can the reverse axial sequence can be selected. It is also possible (in addition or as an alternative) to provide the coil windings adjacent to one another in the radial direction, it being particularly advantageous here to apply the second coil winding to the first coil winding realizing the drive coil so as to be suitable on the shell side; Such a configuration is particularly suitable for radially symmetric embodiments of the electromagnetic actuator, in which the coil means, more preferably cylindrical, enclose the armature unit and the core unit and define the axis of movement of the armature unit by its central axis.

In the electrotechnical realization, it is preferable to design the first coil winding such that an ohmic resistance of <20 ohms is formed, more preferably this may be 6 ohms or less (for inductors in the range between approximately 25 mH for coils <20) Ohms up to 4 mH and down to 0.8 mH for coils <6 ohms). Accordingly, good dynamic properties can be realized. By contrast, it is preferred according to the invention, the second coil winding with an ohmic resistance above 100 ohms, is preferred in particular, a resistor above 400 ohms and <1500 ohms, so that a well evaluable detection signal can be generated and, in cooperation with the first coil winding, no significant current division takes place during energization. Here are typical inductances between about 1 H (400 ohm sensor coil) and about 7 H (500 ohms).

An additional advantage here brings the additionally provided for further training second diode, looped into the second coil winding associated branch: by the first diode (in the branch of the first coil winding) opposite polarity prevents this second diode (realized as a Zener diode) any current flow during energization allows at the same time, in the case of the winding direction or the corresponding contacting which is provided in the opposite way according to the invention, a current flow of the detection signal to the terminals of the dipole.

As a result, the present invention thus achieves a significant improvement in the movement or position detection of anchor means in the context of the generic electromagnetic actuator, with significantly improved dynamic characteristics are achieved and the device is still connected only two poles, in other words, for connection with upstream controllers no additional connections or lines are required.

Thus, the present invention is eminently suitable for use as an actuator for camshaft phasers, but is not limited to this preferred use. Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments and from the drawings; These show in Fig. 1 (a), (b), an equivalent circuit of the coil means according to the invention a first embodiment of the invention with only one, the first coil winding associated diode, in the energized state (a) or in the throw-back state (b) with induced back-off voltage and de-energized main coil;

2 (a), (b) shows an equivalent circuit diagram of the coil means of a second, alternative embodiment of the invention with an additional second diode, associated with the second coil winding, in the energized state (a) or in FIG

Discard condition (b) with induced discard voltage and de-energized main coil;

3 to 5 are schematic longitudinal sectional views of the electromagnetic actuator with possible geometrical-constructive implementation variants of the first and second coil winding.

Thus, Figs. 3 to 5 each as half a longitudinal section through a radially symmetrically realized electromagnetic actuator according to a first preferred embodiment, three variants, as the first and second coil winding may be provided adjacent to each other: one of an elongated anchor tappet 10, a Disc-shaped, axially magnetized permanent magnet 12 and a pair on both sides of the permanent magnet disc 12 provided Flußleitscheiben 14, 16 formed anchor unit is along an axial Direction 18 (as far as the symmetry axis of FIG. 3 to 5) and guided relative to a stationary core unit 20 movable. The armature unit cooperates with an engagement-side plunger 22, which is held by the permanent magnetic adhesive force of the permanent magnet 12 at a front end of the armature plunger 12 releasably adhering. At the opposite end of the permanent magnet 12 engagement end 24 of the engagement ram for cooperation with a (not shown) control partner, in particular a parking cam camshaft adjustment for an internal combustion engine is formed, and for this purpose emerges from a front-side housing surface 26 of a unit surrounding the cylindrical housing 28 out. A bottom plate 30 and a frontal flux guide 32 close magnetic circuits over the housing, wherein in the arrangement shown (and in otherwise known manner) in response to the energization of a first coil winding 34, a repulsive force between the core unit 20 and the permanent magnet assembly 14th , 12, 16, which drives the anchor unit and thus the attaching armature plunger 22 from its rest position shown in FIGS. 3 to 5 into an engagement position (in the figure direction downwards), so that the engagement end 24 can cooperate with the adjusting groove.

The embodiment shown has, adjacent to the first coil winding 34, a second coil winding 36, which in the embodiment of FIG. 3 is axially adjacent to the coil winding 34 in the direction of the permanent magnet unit. Such a form of implementation brings the second coil winding 36, which acts as a detector coil (sensor) for the armature movement in the de-energized state, relatively close to the permanent magnet unit 14, 12, 16, so that high detection quality is ensured. As a variant of the geometrical configuration of FIG. 3, FIG. 4 shows an alternative arrangement of the second coil winding adjacent to the first coil winding (with the same reference numerals for identical or equivalent components and functional groups); Here, the second coil winding 36, in turn axially adjacent, on the permanent magnet unit opposite end of the first coil unit 36; This variant is particularly easy to contact.

The variant of FIG. 5, in turn, with otherwise identical or equivalent realization of the other components or assemblies, the second coil winding 40 radially outwardly lying and wound on the first coil winding 34 and thus advantageously allows additional axial space. Common to all embodiments of FIGS. 3 to 5 shown is that a coil holder (not shown), typically realized from a suitable, magnetically non-conductive plastic injection molding material, carries both coil windings in the respective configurations shown. FIGS. 1 and 2 illustrate the wiring and configuration of the respective coil windings as mutually alternative embodiments. 1 shows in the diagram how the first coil winding (represented by its coil resistor Rhiaupt as well as its inductance L _HaU pt) forms a first branch of a _dipole , to which a first diode D1 is assigned : the intended for supplying current with the purpose of driving the armature unit first winding 34 is energized with a polarity that the voltage drop U _Ha upt along the flow direction of the diode D1 passes, in other words, during energization D1 conducts. The first embodiment of Fig. 1 further illustrates a second, the second coil winding 36 (or 40) corresponding branch in the equivalent circuit diagram shown, said second coil winding is shown as a substitute by their ohmic coil resistance Rsensor or their inductance L _Sen sor- The sense of winding of this coil winding is set up so that one of the lighting current Uhiaupt opposite induction or detector voltage Usensor (induced by the armature movement in the non-energized state) is formed, corresponding to the arrow directions in FIG. Is accessed on the two pole by the two terminals A1, A2, so far comparable to a conventional two-pole connection to a control unit. The current flow through the branch corresponding to the coil winding 36 takes place along the arrow direction l _Sen sor- Fig. 1 (a) shows the Bestromungszustand the main coil 34 (approximately in a constructive implementation of one of the variants of Figures 3 to 5). it conducts the diode D1. In addition, since the windings 34 and 36 are configured relative to one another such that an ohmic resistance of the winding 36 (with about 400 to 1500 ohms) is significantly greater than an ohmic resistance of the first winding 34 (with about 0.1 to 6 Ohms), the current flow in the branch 36 during energization is negligible. In contrast, after completion of the energization by Uschaiten according to Figure 1 (b) and during the discarding or detection operation (when moving the armature unit), the diode D1 by their polarity causes the detection signal U _Se nsor on the terminals of the two-pole A1 , A2 can be tapped off and further processed and does not flow through the branch of the first coil winding 34, as far as the diode D1 blocks. This is symbolized by FIG. 1 (b) in that the current flow I main is blocked by the branch 34; the discard signal is not dissipated over the main coil. The second exemplary embodiment of FIG. 2, insofar as a development of the first exemplary embodiment (again with identical reference symbols for identical or equivalent units), assigns a second diode D2 to the branch of the second coil winding 36, which during the energizing operation (current flow through the first coil winding). blocks, so that no current flow through the serving as a sensor coil second coil winding. During the detector operation, D2 opens, so that in this respect the detection signal (with blocked D1) can flow and in turn can be tapped off via A1, A2. The second diode D2 is implemented as a Zener diode and designed so that it blocks Uschaiten in the Bestromungs- or switching voltage, but has a breakdown voltage which is lower than the induced voltage Usensor- Thus, as symbolized in FIG. 2 (a), blocked in the energization Isensor, so that no opposing field can arise through the coil branch 36. Likewise, the diode D1 prevents analogous to the first embodiment of Figure 1 that the discard signal U _Se nsor on the main coil 34 is reduced; the induced reverse current of the main coil is blocked. Typical implementation variants of the windings with a setting stroke of 3 mm to 6 mm, a typical setting force in the range of 3 N to 15 N and a typical outer diameter of the housing shell of about 20 mm are between 50 and 500 turns for the first coil winding and between approx. 800 and about 8,000 windings for the second winding, resulting in typical inductances of 0.8 mH to 25 mH and 1 H to 70 H, respectively.

The geometrical-constructive implementation forms of FIGS. 3 to 5 show a bistable device; It can be seen that in an extended (engaged) state of the armature unit, the permanent magnet unit 14, 12, 16 at the front end housing end 26, 32 holds (by permanent magnet force), even in a de-energized state of the coil means. A typical provision then takes place in a manner customary for the camshaft adjustment by the action of the adjusting groove cooperating with the engaging ram 22. It is precisely such a bistability preferred for further development that realizes the advantages of the present invention of reliably detecting the movement or setting behavior of the armature unit by means of the second coil winding.

Claims

Electromagnetic actuator with relative to stationary coil means (34, 36; 34, 40) in response to energization of the same drivable anchoring means (10, 12, 14, 16, 22), their movement (vibrators) and / or positioning position relative to stationary, detecting means associated with the coil means (29) cooperating with the coil means, characterized in that the coil means comprise a first coil winding (34) designed to magnetically interact with the armature means by means of the current supply, and a second coil winding (36; 40) designed to generate a detection signal outside the energization of the detection means, the first and second coil windings Forming a two-pole form a parallel connection, and the two-pole electronic switching and / or blocking means (D 1, D2) are assigned so that they prevent short-circuiting of the detection signal (U _Se nsor) on the first coil winding outside the energization. Apparatus according to claim 1, characterized in that the first and the second coil winding have a mutually opposite winding sense and / or an opposite contact and / or a polarity of the energization of a polarity of the detection signal is opposite. 3. Device according to claim 1 or 2, characterized in that the second coil device of the first coil device adjacent, in particular on a common coil carrier, is provided. 4. The device according to claim 3, characterized in that the second coil winding of the first coil winding is provided axially adjacent. Device according to one of claims 1 to 4, characterized in that the second coil winding of the first coil winding radially adjacent, in particular radially outwardly resting, is formed. Device according to one of claims 1 to 5, characterized in that the first coil winding has an ohmic resistance <20 ohms, preferably <10 ohms, more preferably <6 ohms. Device according to one of claims 1 to 6, characterized in that the second coil winding has an ohmic resistance, which is> 100 ohms, in particular> 400 ohms, and <3000 ohms, in particular <1500 ohms. Device according to one of claims 1 to 7, characterized in that a ratio of the ohmic resistances of the second coil winding with respect to the first coil winding> 40, preferably> 100, more preferably> 300, is. Device according to one of Claims 1 to 8, characterized in that the blocking means have a first diode (D1) which is looped into a branch of the bipole associated with the first coil winding. Device according to Claim 9, characterized in that the blocking means have a second diode (D2) inserted into a branch of the bipole associated with the second coil winding. Device according to one of claims 1 to 10, characterized in that the armature means are magnetically associated with the core means cooperating permanent magnet means (12) which generate a repulsive force on the core means in response to the energization. Device according to one of claims 1 to 1 1, characterized in that the plunger-like design anchor means having an engagement end (24) which is designed to cooperate with a camshaft adjustment of an internal combustion engine enabling positioning partner, wherein preferably the adjusting partners designed to realize a return of the anchor means are.