Abstract
A bistable electromagnetic actuator device, a permanent magnet means (12; 12a, 12b), as well as an armature unit (18) with an elongate plunger unit (10) extending along a moving direction, wherein said armature unit can be moved into at least one of two end and/or stop positions that are stable in the deenergized state by means of stationary electromagnetic driving means (22), wherein stationary magnetic field detector means (34; 34a, 34b) are assigned to a housing (20), which at least sectionally encloses the armature unit, for the contactless interaction with the permanent magnet means in at least one of the end or stop positions provided for the armature position detection, wherein the plunger unit features a terminal contact and/or engagement section (28) for interacting with an actuating partner in a contacting and non-positive fashion such that a non-positive contact and/or actuation by the actuating partner causes a motion of the armature unit into one of the end or stop positions, in which the armature unit remains in a stable fashion in the deenergized state, when the electromagnetic driving means are deactivated, and wherein the magnetic field detector means are arranged and wired for generating and outputting a detector signal corresponding to this end or stop position.
Claims
1. A bistable electromagnetic actuator device, a permanent magnet means (12; 12a, 12b), as well as an armature unit (18) with an elongate plunger unit (10) extending along a moving direction, wherein said armature unit can be moved into at least one of two end and/or stop positions that are stable in the deenergized state by means of stationary electromagnetic driving means (22), wherein stationary magnetic field detector means (34; 34a, 34b) are assigned to a housing (20), which at least sectionally encloses the armature unit, for the contactless interaction with the permanent magnet means in at least one of the end or stop positions provided for the armature position detection, wherein the plunger unit features a terminal contact and/or engagement section (28) for interacting with an actuating partner in a contacting and non-positive fashion such that a non-positive contact and/or actuation by the actuating partner causes a motion of the armature unit into one of the end or stop positions, in which the armature unit remains in a stable fashion in the deenergized state, when the electromagnetic driving means are deactivated, and wherein the magnetic field detector means are arranged and wired for generating and outputting a detector signal corresponding to this end or stop position.
2. The device according to claim 1, wherein the driving means are realized in the form of a stationary coil unit that is provided on or in the housing and assigned a stationary core unit, which forms a stopping face (26) for a stopping section of the armature unit, wherein the plunger unit (10) preferably extends into the core unit or through this core unit in a guided fashion.
3. The device according to claim 2, wherein the permanent magnet means are realized in the form of disk-shaped permanent magnet bodies (12; 12a, 12b), which are provided on the plunger unit axially on both ends of the core and/or coil unit and designed in such a way that one of the permanent magnet bodies respectively contacts the core or coil unit while the other permanent magnet body is axially spaced apart from the core or coil unit in the two end or stop positions.
4. The device according to claim 1, wherein the magnetic field detector means are semiconductor-based and/or realized by means of a detector coil and provided on the magnetically conductive housing in such a way that the housing is detection-effectively permeable to the permanent magnetic field of the permanent magnet means in the end or stop positions provided for the armature position detection, wherein the housing features a housing aperture, a housing opening and/or a housing section, which at least sectionally is magnetically non-conductive for this purpose.
5. The device according to claim 3, wherein the magnetic field detector means are provided axially on both ends of the core or coil unit.
6. The device according to claim 1, wherein the magnetic field detector means are provided on one end of the stationary driving means, such that a plurality of positions of the armature unit preferably can be detected by an assigned plurality of detector elements of the magnetic field detector means.
7. The device according to claim 1, wherein the contact and/or engagement section is designed for producing a mechanical contact and/or connection with the actuating partner, which can be effectively subjected to pressure and/or tension in or opposite to the moving direction.
8. The device according to claim 7, wherein the contact and/or engagement section features or forms a mechanical coupling, a thread section, a peripheral groove, an undercut and/or a probe head.
9. The device according to claim 1, wherein energy accumulator means (44) are assigned to the armature unit in order to generate a counterforce that acts opposite to the contact or actuation by the actuating partner, wherein said energy accumulator means are realized in the form of a flat coil spring and/or pressure spring arranged concentric to the plunger unit.
10. A utilization of the bistable electromagnetic actuator device according to claim 1 as a motion and/or position sensor for the actuating partner and/or for detecting a motion or change in position of the actuating partner.
11. The utilization according to claim 10, wherein a position of the armature unit actuated by the actuating partner in the deenergized state is stored.
12. A system consisting of an actuating partner to be evaluated or to be monitored for the position and/or motion detection and the device according to claim 1.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Other advantages, characteristics and details of the invention result from the following description of preferred exemplary embodiments with reference to the figures; in these figures,
[0021] FIG. 1 shows a schematic longitudinal section through the bistable electromagnetic actuator device according to a first exemplary embodiment of the present invention, in which only one permanent magnet body forms the permanent magnet means;
[0022] FIG. 2 and FIG. 3 respectively show a longitudinal section analogous to FIG. 1 through a second and preferred exemplary embodiment of the invention, in which the permanent magnet means are formed by two permanent magnet bodies arranged axially to both sides of the stationary electromagnetic driving means and FIGS. 2, 3 respectively show the end or stop positions;
[0023] FIG. 4 shows a variation of the second exemplary embodiment according to FIGS. 2, 3, in which additional detectors of the magnetic field detector means are furthermore provided;
[0024] FIG. 5 shows a schematic representation with an illustration of different individual or cumulative arrangement options for individual detectors of the inventive magnetic field detector means in the exemplary embodiment according to FIGS. 2, 3;
[0025] FIG. 6 shows a variation of the detection by means of terminally provided detector coils for realizing the magnetic field detector means in the exemplary embodiment according to FIGS. 2, 3;
[0026] FIG. 7 shows another variation of the exemplary embodiment according to FIGS. 2, 3, in which spring means are provided opposite to an actuating direction, and
[0027] FIG. 8 shows a generalization of the inventive idea of the first embodiment in the form of a generic exemplary embodiment, in which a schematically illustrated modular, independent actuator in the form of an assembly is utilized within an actuator device according to the first exemplary embodiment illustrated in FIG. 1.
DETAILED DESCRIPTION
[0028] In the following description of exemplary embodiments, identical or identically acting functional components of the illustrated exemplary embodiments are identified by the same reference symbols.
[0029] The schematic longitudinal section through the bistable electromagnetic actuator device according to the first exemplary embodiment illustrated in FIG. 1 shows an elongate, axially extending plunger unit 10 (with “axial” in the context of the invention referring to an axis that extends along the moving direction and therefore transverse to the plane of projection of FIG. 1), wherein an (axially magnetized) permanent magnet disk 12 is seated on said plunger unit and bordered by (otherwise known) flux-conducting disks 14 and 16 on both ends. The thusly formed armature unit 18 is guided in a housing 20 such that it can be axially moved relative to electromagnetic driving means 22 in the form of a core unit 24 and a (not-shown) coil unit surrounding this core unit, wherein the stator core terminally forms a stationary stopping face 26 (in the form of an otherwise known anti-adhesion spacer disk) in the direction of the permanent magnet means 12.
[0030] The hollow-cylindrical housing 20 made of magnetically conductive sheet metal is respectively closed on its faces (in a magnetically conductive fashion), wherein a disk-shaped housing wall 26 provides an opening for an end of the plunger 10 on one end (the right end in FIG. 1) and a disk-shaped housing wall section 30 likewise provides a stop and a stable deenergized holding position for the armature unit (more precisely: the permanent magnet unit 12 with adjoining flux-conducting disks 14, 16) on the other end in the direction of an engagement end 28 of the plunger 10. FIG. 1 insofar elucidates a first of two stable deenergized end or stop positions of the armature unit relative to the driving means in the housing.
[0031] The device illustrated in FIG. 1 is configured for the detecting interaction with an actuating partner 32, which is merely illustrated schematically and can act upon the plunger unit 10 and therefore the armature unit 18 in order to exert a force of pressure (in the rightward direction in the plane of projection of FIG. 1). Accordingly, the engagement section 28 provided on the end of the plunger 10 consists of a planar, disk-shaped surface.
[0032] A magnetic detector element 34 is provided in the lower surface area of the housing 20 illustrated in FIG. 1, wherein said magnetic detector element is seated in a cutout in the housing shell (which is closed with a magnetically non-conductive material) and thereby can interact with the permanent magnetic field of the permanent magnet disk 12 in a detecting fashion. In this case, the Hall sensor 34 is realized and designed in such a way that a detection signal or position signal is generated in the stop position illustrated on the left side in FIG. 1 whereas a different sensor signal to be evaluated and then electronically processed by (not-shown) evaluation means is generated in the opposite stop position of the armature unit 18 (in this case, the permanent magnet unit 12 would adhere to the core 24 in a deenergized fashion and the disk 14 would accordingly rest on the outer surface 26).
[0033] The device illustrated in FIG. 1 operates as described below: when an actuating partner 32 exerts a force of pressure upon the armature unit 18 by means of the engagement face 28, e.g. due to a rightward motion along the axial direction in FIG. 1, the armature unit moves rightward from the end or stop position illustrated on the left side up to the stop on the core region as soon as the exerted force exceeds the permanent-magnetic adhesive force on the housing end face 30. In addition, a permanent-magnetic force of attraction acts between the permanent magnet disk 12 and the (stationary) core 24 as soon as a magnetic interaction takes place and thereby boosts the motion. The coil in the driving unit 22 is deenergized during this operation; the device acts as a position sensor or motion sensor for the actuating partner 32: as soon as the permanent magnet 12 leaves the effective detection range of the magnetic field sensor 24 as the actuation and therefore the motion of the armature unit continues, the signal of this detector changes such that the change in position caused by the actuating partner 32 is reliably detected and available for being evaluated.
[0034] In a subsequent state, in which the armature position relative to the housing may, if applicable, also be unclear or undefined (e.g., because an intermediate deenergized state does not allow an electronic position storage), an energization of the coil provided in the unit 22 would then conventionally cause the armature unit to once again move back into the extended (starting) position illustrated in FIG. 1 due to the repulsive effect on the permanent magnet unit 12. The actuator system, which is integrated into the housing 20 in this exemplary embodiment, therefore makes it possible to establish a defined armature position at any time, namely in that the position according to FIG. 1 is purposefully established in interaction with the actuating partner 32 by means of energization, if applicable, prior to carrying out the above-described detecting or measuring operation.
[0035] In this case, all processes and components are enclosed by the housing (which in the preferred embodiment is realized cylindrically and therefore configured radially symmetrical) as illustrated in the figure and correspondingly well protected against various types of environmental influences, e.g. moisture, temperatures, vibrations or the like, such that the invention is ideally suitable for correspondingly stressful operating environments.
[0036] FIGS. 2 and 3 show an alternative variation of the exemplary embodiment according to FIG. 1, wherein the permanent magnet means in the exemplary embodiment according to FIGS. 2 and 3 are respectively realized in the form of a left permanent magnet unit 12a and a right permanent magnet unit 12b (referred to the plane of projection), i.e. to both sides of a centric stator unit that is once again realized in the form of a stationary core 26 and a (not-shown) coil means assigned thereto; the core now provides stopping faces 26 for interacting with the respective permanent magnet arrangement 12a, 12b axially on both sides, wherein the elongate plunger unit 10 connecting these permanent magnet disks 12a, 12b (with respectively assigned disks 14, 16) extends axially and centrally through the stationary driving unit 22 and is thusly guided thereby.
[0037] In the exemplary embodiment according to FIGS. 2, 3, FIG. 2 shows a first end or stop position, in which the right permanent magnet section 12b of the armature unit is (insofar deenergized and adhesively) in contact with the stationary core whereas FIG. 3 shows the opposite end or stop position; in this case, the permanent magnet unit 12a is in contact with the core 26 (with adjacent sides 16, 14) whereas the permanent magnet unit 12b maintains an axial clearance from the core. A comparison between FIG. 3 and FIG. 2 shows that this change in position in the form of a change-over of sorts once again takes place in the form of an actuation by the actuating partner 32 due to a horizontal (in the figures rightward) force application upon the planar engagement end 28 on the face of the plunger 10. It should be noted that a cylinder 38, which is open on both ends, is provided for the housing in the exemplary embodiment according to FIGS. 2, 3; in contrast to the first exemplary embodiment according to FIG. 1, a closing wall is neither required in the open housing region on the left side nor in the right open region. In fact, a centric, fixed (stationary) core region 22 exclusively defines both stop positions of the horizontally movable armature unit.
[0038] FIGS. 2, 3 schematically show a pair of Hall sensors 34a, 34b that respectively protrude into the open housing end regions in this case, for example, in order to simplify their mounting or magnetic field coupling to the respective permanent magnet disks 12a, 12b (the configuration according to FIGS. 2, 3 may basically also be realized with non-magnetic or magnetically non-conductive retaining means, which can be suitably provided in this region in order to mount the sensor elements). Sensor elements 34a and 34b are respectively assigned to each of the permanent magnet elements 12a, 12b as shown such that the position detection of the armature unit including plunger 10 and therefore also of the engaging actuating partner 32 can insofar be carried out specific to the respective application and with a high degree of detection reliability.
[0039] In the exemplary embodiment according to FIGS. 2, 3, an energization of the stator coil would then once again lead to the armature being purposefully moved into the stop position of the permanent magnet means on the left side (FIG. 2) or the stop position of the permanent magnet means on the right side (FIG. 3)—depending on the polarity of the energization—such that the flexibility and applicability or adaptability of the detection is additionally increased in this respect and in comparison with the first exemplary embodiment according to FIG. 1. Although not illustrated in FIGS. 2, 3, it is also possible, e.g., to suitably assign a second actuating partner to the plunger 10 in an end region that lies opposite of the end face 28 (wherein this can basically also be realized in the first exemplary embodiment 1).
[0040] FIGS. 4 and 5 show other options for providing the detector functionality on the mechanical design according to FIGS. 2, 3; for example, the reference symbols 34c, 34d designate other options for providing detector elements; in this respect, the exemplary embodiment according to FIG. 4 would double the detection reliability for a position detection because two detector elements would then be assigned to each stop or end position and two detector signals could accordingly be evaluated. The redundancy of such an embodiment would therefore be particularly suitable for sensitive or failure-prone applications. In contrast, FIG. 5 schematically shows basic options for the arrangement of magnetic field sensors, e.g. semiconductor-based sensors of the Hall sensor type, which are respectively identified by the designation “Sensor”: it becomes clear that sensors can not only be arranged along the moving path (and also, e.g., in axial intermediate positions), but sensors in fact can also be arranged in a radially offset fashion, namely starting from a respective end face, as well as with respect to potential installation positions on or in the central stator arrangement.
[0041] In contrast, the exemplary embodiment according to FIG. 6, which is otherwise structurally comparable to the functionality according to FIGS. 2, 3, shows a variation of the arrangement of semiconductor-based Hall magnetic field sensors on the respective faces in the form of the terminal arrangement of a magnet coil detector 40, which generates a correspondingly variable coil signal to be further evaluated and processed in response to a change in position of the free end 42 of the plunger unit 10 (caused by the armature motion).
[0042] The exemplary embodiment according to FIG. 7, which is otherwise structurally comparable to the exemplary embodiment according to FIGS. 2, 3, shows an example of the pressure spring 44 on the right side, which is inserted concentric to the plunger 10, and how a compressive or motive actuation of the detector unit due to a rightward force application by the actuating partner 32 encounters an opposing spring force (corresponding to the required compressive force of the pressure spring 44) and therefore provides the option of thusly or otherwise influencing the detection behavior. Such a spring solution could be particularly suitable for homogenizing a strongly vibrating force signal of the actuating partner 32 or for otherwise achieving an improved mechanical reactivity of the arrangement shown.
[0043] FIG. 8 shows how an actuator unit, which is terminally attached to the housing 20′ in the form of a separate encapsulated plunger unit 50, realizes the electromagnetic motion of the armature unit with its plunger section 52 that can be extended from the housing, namely in the form of a potential alternative embodiment of the basic inventive principle according to FIG. 1, but alternatively also in the form of a potential variation of the exemplary embodiment according to FIGS. 2, 3 and exemplary embodiments derived thereof; in this case, the armature unit (FIG. 1) would be reduced to a significantly shortened plunger unit 10 with contacting permanent magnet body 12 (including two adjacent disks 14, 16); the actuator plunger 52, which can be extended from the end of the actuator housing 50 indicated in the form of a black box, would in this respect exert a leftward actuating force upon the armature 10, 12 (opposite to a rightward force of pressure or thrust of the actuating partner 32 to be detected). This principle, which utilizes an otherwise known actuator in the form of a complete assembly 50 for the further modularization, can be likewise applied to the exemplary embodiment according to FIGS. 2, 3, in which case an actuator plunger would have to be axially extended from both ends of this actuator in order to respectively displace one of the permanent magnet assemblies in an analogous fashion.
