EP3591673A1 - Electromagnetic actuator - Google Patents

Abstract

The present electromagnetic actuator (1) is suitable for locking applications, for example security locks, and has an electrically energizable coil (3) which is at least partially enclosed by a jacket body (4) and a yoke piece (5). An armature (7) which is movably mounted in the axial direction (A) is provided within the coil (3) and cooperates with a restoring element (8) and is movable between a first end position (P1) and a second end position (P2). Transversely to the axial direction (A) of the armature (3) there is at least one locking element (10) which can be at least partially flooded by magnetic field lines (F) and which interacts with the armature (7) in such a way that it moves in at least one of its end positions (P1, P2 ) can be locked or unlocked by the locking element (10). The locking element (10) comprises a permanent magnet (13) firmly connected to it, preferably inside, and is movably mounted within a locking guide (14) provided in a guide ring (11). To lock the locking element (10) engages in a recess (15), respectively. in a circumferential groove (18) of the armature (7). Advantageously, this locking element (10) is not perpendicular to the axial direction (A) of the armature (7), but is inclined to a transverse plane perpendicular to the axial direction, i.e. In a further development, the reset element (8) is designed in the form of a counter coil to generate a reversing stroke and the actuator (1) is therefore also suitable for bistable use of all kinds, for example in driving authorization systems in automotive engineering Sorting switch systems in automation technology, in access control systems in rail technology or in door locking systems in security technology.

Description

The present invention relates to an electromagnetic actuator for locking applications, for example for security locks according to the preamble of main claim 1.

Actuators can be used in a variety of ways and can be used in a wide variety of areas, for example in control and regulation technology, in robotics or mechatronics or in sorting systems in delivery centers. The present actuator should preferably be used in connection with a security lock, as can be found primarily for securing access to living, business and laboratory rooms or detention cells, as well as for theft protection, in particular in weapon or valuables cabinets (bank safes).

Electromagnetic actuators and their mode of operation are, for example, from the DE-10'2014'224'043 known. These essentially comprise a coil, an armature which can be displaced between two positions in this coil, a coil housing which at least partially surrounds the coil, and a locking means for mechanically fixing the armature in one of its positions, the locking means generally by energizing the coil can be unlocked. Actuators of this type differ essentially in their locking means. For example, in the DE-29'903'873 described an electromagnetic actuator, the armature of which can be fixed in one of its positions with the aid of soft magnetic locking elements which can be moved transversely to the direction of movement of the armature. When the coil is energized, these locking elements are penetrated by the generated magnetic field and can thus be moved against a spring force from a first position to a second position in order to lock or unlock the armature in one of these positions. Unfortunately, these soft magnetic locking elements wear out quickly, especially when operated with force, and do not allow long-term stable use in a security lock.

It has therefore already been proposed to use mechanically robust bolts for securing the locking in electromagnetic locking devices, such as from US 5'216'909 known. This device comprises several spring-loaded pins that hold a robust locking bolt for securing the locking bolt in its locking position. Electromagnetic lifting magnets of a known type are used to activate or deactivate the at least two pins that position the securing locking bolt. Unfortunately, such locking devices prove to be undesirably large in volume and complex in their construction.

There is therefore a desire in the above-mentioned areas for the functioning of electromagnetic security locks to save space, i.e. without long-term construction and without sacrificing robustness.

It is therefore an object of the present invention to provide a simple, robust and durable electromagnetic actuator which is suitable for use in a security lock with self-locking.

According to the invention, this object is achieved by an electromagnetic actuator having the features of claim 1 and in particular by an electromagnetic actuator having an armature which has at least one locking element, the locking element comprising a permanent magnet fixedly attached therein.
This locking element is movably supported within a locking guide provided in a guide ring and engages for locking in a recess provided in the armature of the actuator.

This locking element is preferably located radially to the axial direction of the armature. In a preferred embodiment of the actuator according to the invention, the locking element is arranged inclined to a transverse plane perpendicular to the axial direction of the armature. In this embodiment the recess also has an inclined bottom and / or at least one inclined or stepped flank.

It goes without saying that, in accordance with the requirements, several, in particular three, locking elements can be arranged in a spoke-like manner around the armature. It is advisable to design the recess in the form of a circumferential groove and the floor, respectively. the flanks in a suitable manner so that the mechanical locking on the one hand and the electromagnetic unlocking on the other hand are optimally possible. It goes without saying that the person skilled in the art optimizes not only the shape of the mentioned recess but also the position of the permanent magnet attached to the locking element relative to the armature and coil of the electromagnetic actuator, depending on the requirements and dimensions of the same, i.e. this situation is predetermined at least experimentally.

In the present case, the term “radial to the axial direction of the armature” is understood to mean a directional beam radiating from a point lying on the central axis of movement of the armature. This directional beam can either lie in a transverse plane perpendicular to the axial direction or be inclined to it, in particular lie on a conical lateral surface that extends from this point. In contrast, in the present case, the term “spoke-like distributed locking elements” is only to be understood as a uniform distribution of the locking elements around the armature.

In a preferred use of the actuator according to the invention, the armature actuates a bolt, for example for setting the switch in a sorting system of a delivery service or for a door lock, and for this purpose the armature assumes a first end position, in particular a closed position, when the coil is de-energized and takes it when energized the coil a second end position, in particular a release position. In this embodiment, the permanent magnet assumes a position relative to the armature and coil when locked, so that when the coil is energized it is exposed to a magnetic force generated by the stray field of the coil around the locking element to move out of the closed position. This ensures that the lock remains in place even in the event of a power failure.

According to the invention, the locking element is essentially non-magnetic, i.e. has a neutral or only slight para- or diamagnetic permeability of µ ≈ 1 and is made of a material with high strength, in particular with high breaking strength, depending on the use of the actuator.

When the present actuator is in operation, the armature assumes a first end position when the coil is de-energized and with the aid of a spring element, preferably a return spring, in which the locking element engages in a recess in the armature and is also held there by means of the permanent magnet. When the coil is energized, a magnetic field is built up, the field lines of which essentially flow through the ferromagnetic material, ie occur collectively in the armature, in the jacket body and in the yoke. Only a small part of the magnetic field generated by the coil fills the space outside the soft magnetic magnetic frame and forms a magnetic-specific stray field, the field lines of which run outside around the yoke and the jacket body. According to the invention, this stray field serves to repel the permanent magnet from the armature, ie to push the locking element out of the locking position. The armature is thus released and, against the restoring force of the spring element, it can move into the coil interior and into a second end position, ie the release position. This unlocking movement is made possible by an orientation of the permanent magnet which is adapted to the coil winding direction, ie the permanent magnet provided, for example, on the locking side is used in such a way that its magnetic north pole is directed towards the armature when the magnetic north pole of the magnetic field generated is also on the locking side. It goes without saying that when the coil winding direction is opposite, the permanent magnet is used in such a way that its magnetic south pole is directed toward the armature. In any case, the permanent magnet should be oriented such that it pulls the locking element towards the armature when the coil is de-energized and repels the locking element from the armature when the coil is energized.

It goes without saying that the present actuator for a security lock can be integrated directly into any desired flap, door or window frame, but can also be used in other areas, in particular in massive high-security systems or for activating an adjustment element used in another way , such as in a sorting system of a delivery center.

Fig. 1:

schematisch dargestellter Längsschnittes durch einen erfindungsgemässen Aktuator im verriegelten Zustand;

Fig. 2:

schematisch dargestellter Längsschnittes durch einen erfindungsgemässen Aktuator im entriegelten Zustand;

The present invention is to be explained in more detail below using an exemplary embodiment and with the aid of the figures. It shows:

Fig. 1:

schematically illustrated longitudinal section through an actuator according to the invention in the locked state;

Fig. 2:

schematically illustrated longitudinal section through an actuator according to the invention in the unlocked state;

The in Fig. 1 The illustrated electromagnetic actuator 1 comprises an electromagnet with a known structure, ie comprises a coil 3 lying in a winding support 2, which are surrounded in a known manner by a jacket body 4 and a yoke piece 5. In particular, the sheathing body 4 does not need to completely enclose the coil 3, but can, for example, be designed as a frame, in particular in order to facilitate access to contact plugs for energizing the coil 3. A pole piece 6 is firmly connected to the sheath body 4 and closes off the interior of the coil 3 in a known manner. This coil interior is preferably lined with a bearing tube 9 of a known type, in which an armature 7 is movably mounted. A restoring element 8 cooperating with this armature 7, in particular in the form of a spiral spring, is supported on the one hand on a guide ring 11 firmly connected to the yoke piece 5 and on the other hand on a spring plate 12 firmly connected to the armature 7, around the armature 7 when the coil 3 is not energized pull out of the coil interior and bring it into its end position P1 shown here. With an amagnetic, preferably held in the pole piece 6 and engaging in the armature 7, the adjusting screw 17 Limit the stroke of the armature 7 in a simple manner, ie the end position P2 of the armature 7 can be set in the desired manner when the coil 3 is energized.

According to the invention, a locking element 10, which is slidably mounted in a locking guide 14, is provided in the guide ring 11, which is firmly connected to a permanent magnet 13 and locks the armature 7 in its end position P1. The permanent magnet 13 permanently presses the locking element 11 against the armature 7 because of the attractive forces between the permanent magnet 13 and the ferromagnetic armature 7 and allows this locking element 10 to engage in a recess 15, thus preventing any further and undesirable movement of the armature 7. The locking element 10, which is slidably mounted in the locking guide 14 in the guide ring 11, is secured here with a locking ring 16 mounted on the guide ring 11. It is understood that a plurality of locking elements 10 can be provided in this guide ring 11. In a preferred embodiment, these locking elements 10 are arranged radially to the axial direction of movement A of the armature 7 and preferably arranged in a spoke-like manner around the armature 7. For this purpose, the recess 15 is designed in the form of a circumferential groove 18. In order to increase the stability of the locking, the plurality of locking elements 10 can be arranged inclined to a transverse plane perpendicular to the axial direction A of the armature 7 and the circumferential groove 18 has a bottom area 19 that drops off on the coil side. In order to facilitate unlocking, this circumferential groove 18 has a suitably stepped flank area 20 on the coil side.

The in Fig. 2 schematically represented section through the actuator 1 according to the invention shows this when the coil 3 is energized. The construction of the electromagnet shown here corresponds to the arrangement already described, ie comprises a coil 3 lying in a winding support 2, which in a known manner comprises a jacket body 4 and a yoke piece 5 are surrounded. Here, too, the sheathing body 4 does not need to completely enclose the coil 3, but can, for example, be designed as a frame, in particular in order to facilitate access to contact plugs for energizing the coil 3. A pole piece 6 is firmly connected to the jacket body 4 and closes in a known manner Manner of the interior of the coil 3. This coil interior is preferably lined with a bearing tube 9 of a known type, in which an armature 7 is movably mounted. A restoring element 8 cooperating with this armature 7, in particular in the form of a spring-elastic element, for example a spiral spring, is supported on the one hand on a guide ring 11 firmly connected to the yoke piece 5 and on the other hand on a spring plate 12 firmly connected to the armature 7, around the Pull armature 7 out of the coil interior when the coil 3 is not energized. With an amagnetic, preferably held in the pole piece 6 and engaging in the armature 7, adjusting screw 17, the stroke of the armature 7 can be limited in a simple manner, ie the end position P2 of the armature 7 can be adjusted when the coil 3 is energized, as shown here.

The locking element 10 slidably mounted in the guide ring 11 in the locking guide 14 is, according to the invention, firmly connected to a permanent magnet 13 and no longer engages in the cutout 15 or the current when the coil 3 is energized. circumferential groove 18, ie allows the movement of the armature 7 in its second end position P2, respectively. Release position. The permanent magnet 13 pulls the locking element 11 because of the magnetic repulsive forces between the permanent magnet 13 and the magnetic stray field F generated by the coil 3 from the recess 15, respectively. circumferential groove 18 out. It is understood that the pole of the permanent magnet 13 facing the armature 7 has the same polarity as the pole of the coil 3 facing the permanent magnet 13. At the same time, when the coil 3 is energized, the armature 7 is pulled into the coil interior. In order to facilitate this unlocking movement, the flank area 20 of the circumferential groove 18 on the coil side can be designed in steps. As already described, the locking element 10, which is displaceably mounted in the guide ring 11, is secured with a locking ring 16 attached to the guide ring 11. A plurality of locking elements 10 can be provided in this guide ring 11. In a preferred embodiment, these locking elements 10 are arranged radially in relation to the axial direction of movement A of the armature 7 and preferably in a spoke-like manner around the armature 7. It goes without saying that wherever a stray field generated by the coil can be, in particular in front of or behind or inside the coil arrangement, at least a locking element 10 interacting with the armature 7 can be provided.

In a special development of the actuator 1 according to the invention, it is designed in the form of a bistable reversing lifting magnet, i.e. this has a reset element 8 in the form of an oppositely wound or controlled counter-coil and thus enables a reverse stroke. The locking element 10 and the associated recess 15 in the armature 7 can also be arranged in front of or behind each of the coils or between the two coils. An actuator 1 designed in this way can be used in bistable applications of all kinds, for example in automotive technology for driving authorization systems, in automation technology for sorting switches, in railway technology for access control systems and in security technology for door locks, etc.

In a further development of the actuator according to the invention, the essentially non-magnetic locking element, depending on the use of the actuator, is made of a material with high strength, in particular with high breaking strength, such as a brass alloy with a tensile strength of 230 to 610 N / mm ² or from a chromium-molybdenum alloy with a tensile strength of, for example, up to 1,000 N / mm ² or from a technical plastic, such as, for example, from a plastic reinforced with carbon nanotubes with a tensile strength of, for example, up to 630,000 N / mm ² . The locking element primarily has a high shear strength and / or fatigue strength, ie fatigue strength.

Alternatively, the jacket body 4 and / or the yoke piece 5 can be provided with additional components in order to influence the field line course of the stray field and in particular thus to optimize the repulsive forces between the permanent magnet 13 and the armature 7.

The advantages of the present actuator are immediately apparent to the person skilled in the art and can be seen in particular in the component-reduced and therefore surprisingly simple construction, ie in the space-saving and functionally reliable design. In addition, the actuator according to the invention allows this adapt easily to desired requirements, especially for use in a low-wear, ie long-term stable security lock.

reference numeral

1

actuator

2

winding support

3

Kitchen sink

4

covering body

5

yoke piece

6

pole piece

7

anchor

8th

Return element

9

Bearing pipe

10

locking element

11

guide ring

12

spring plate

13

permanent magnet

14

locking guide

15

recess

16

lock ring

17

screw

18

circumferential groove

19

floor area

20

flank area

A

axially

P1

first end position

P2

second end position

F

magnetic field lines

Claims (11)

Electromagnetic actuator (1) for locking applications, for example for security locks, which actuator (1) has an electrically energizable coil (3) which is at least partially enclosed by a jacket body (4) and a yoke piece (5), with inside the coil ( 3) an armature (7) movably mounted in the axial direction (A) is provided, which cooperates with a return element (8), in the form of a spring-elastic element and / or a counter-coil for generating a reversing stroke, and between a first end position (P1) and a second end position (P2) is movable,
At least one locking element (10) which can be at least partially flooded by magnetic field lines (F) is provided transversely to the axial direction (A) of the armature (3) and cooperates with the armature (7) in such a way that it engages in at least one of its end positions (P1, P2) can be locked or unlocked by at least one locking element (10),
characterized in that
the locking element (10) comprises a permanent magnet (13) fixedly connected to the latter, preferably inside, and which locking element (10) is movably mounted within a locking guide (14) provided in a guide ring (11), the locking element (10 ) engages in a recess (15) in the armature (7) for locking. Electromagnetic actuator (1) according to claim 1, characterized in that the armature (7) assumes the first end position (P1) when the coil (3) is not energized and the second end position (P2) when the coil (3) is energized, the first end position (P1) is a closed position and the second end position (P2) is a release position. Electromagnetic actuator (1) according to one of claims 1 or 2,
characterized in that the locking element (10) has a neutral or only slight paramagnetic permeability of µ ≈ 1. Electromagnetic actuator (1) according to claim 3, characterized in that the permanent magnet (13) of the locking element (10) has a predetermined position relative to the armature (7) and coil (3) when locked, such that the permanent magnet (13) of the locking element (10) when the coil (3) is energized is exposed to a magnetic force generated by the stray field of the coil (3) in order to move the locking element (10) out of the predetermined position. Electromagnetic actuator (1) according to claim 4, characterized in that the locking element (10) is arranged radially to the axial direction (A) of the armature (7). Electromagnetic actuator (1) according to claim 4, characterized in that the locking element (10) is arranged inclined to a transverse plane perpendicular to the axial direction (A) of the armature (7). Electromagnetic actuator (1) according to one of the preceding claims 1 to 6, characterized in that several, in particular three, locking elements (10) are arranged in a spoke-like manner around the armature (7). Electromagnetic actuator (1) according to one of the preceding claims 1 to 7, characterized in that the recess (15) is designed in the form of a circumferential groove (18). Electromagnetic actuator (1) according to Claim 8, characterized in that the groove (18) has a bottom region (19) which slopes away on the coil side and preferably a flank region (20) which is stepped on the coil side. Electromagnetic actuator (1) according to one of the preceding claims 1 to 9, characterized in that the locking element (10) is made from a technical material with high strength, in particular with high breaking strength, for example from a brass alloy with a tensile strength of 230 to 610 N / mm ² or made of a chrome-molybdenum alloy with a tensile strength of e.g. up to 1,000 N / mm ² or made of a plastic reinforced with carbon nanotubes with a tensile strength of e.g. to 630,000 N / mm ² , the technical material primarily having a high shear strength and / or fatigue strength, ie fatigue strength. Use of an electromagnetic actuator (1) with the features of claim 1 in bistable applications, in particular in automotive technology in driver authorization systems, in automation technology in sorting switch systems, in rail technology in access control systems or in security technology in door locking systems.

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