EP2732455B1 - Electromagnetic drive - Google Patents

Description

The invention relates to an electromagnetic drive for an electrical switch, in particular an electrical circuit breaker, with at least one movable armature which can perform a lifting movement along a predetermined sliding direction, directly or indirectly connected to a movable switching contact of the switch and in a closed position at a first armature-side abutment surface with a first magnetically conductive yoke part of the drive and at a second armature-side abutment surface with a second magnetically conductive yoke part of the drive includes a magnetic circuit of the drive, at least one permanent magnet, a magnetic field for the magnetic circuit and a holding force to Holding the armature generated in the closed position, and at least one coil which is arranged such that a current flow through the coil, a magnetic flux can be caused, the magneti the magnetic flux is equal or opposite in the magnetic circuit, the electromagnetic drive after assembly allows a Nachjustagezustand by selbstjustage the position of the first and second yoke member relative to each other by the magnetic force of the permanent magnet is possible, and wherein the yoke parts in a fixed mounted state can be brought by the orientation of the yoke parts is fixed regardless of the further positioning of the armature, wherein in the Nachjustagezustand the magnetic circuit is closed by the armature and at least two yoke parts of the drive along the sliding direction of the armature relative to each other are displaceable , So that - driven by the magnetic force of the permanent magnet - the yoke-side abutment surface of the first yoke part is self-aligning brought to a distance to the yoke-side abutment surface of the second yoke part with the distance between the first and the second anchor-side abutment surface along the predetermined sliding direction is identical.

A drive is for example from the published patent application EP 0 321 664 known. This drive has a movable armature, which can perform a lifting movement along a predetermined sliding direction and can be connected to a movable switching contact of a switch. In addition, the drive comprises a permanent magnet which generates a magnetic field and a holding force for holding the armature in a predetermined position. A coil is arranged such that the drive can be actuated by a current flow and the armature can be moved.

An electromagnetic drive of the type mentioned is from the US 2009/072636 A1 known.

The invention has for its object to provide a drive that allows a subsequent adjustment of the components and a subsequent correction of manufacturing tolerances.

This object is achieved in that the at least two displaceable relative to each other along the sliding direction of the armature yoke parts are bolted together, wherein a screw is passed through a hole in one of the two yoke parts and bolted to the other of the two yoke parts, wherein the diameter of Hole along the sliding direction of the armature is greater than the diameter of the screw, wherein in loose screw and closed position of the armature, the yoke parts are in Nachjustagezustand and wherein firmly tightened screw the yoke parts are in the fixed state.

A major advantage of the drive according to the invention is that this due to the subsequent Selbstjustagemöglichkeit also with relatively large manufacturing tolerances manufactured components can be mounted very little effort; because the electromagnetic drive can be readjusted after installation by the invention provided for magnetic self-adjustment with respect to the arrangement of the first and the second yoke part with very little effort. The readjustment takes place by the magnetic force of the permanent magnet automatically such that the first and the second yoke part are aligned with an optimal distance from each other.

The at least one permanent magnet is preferably arranged such that it adjoins at least one of the yoke parts of the drive.

The diameter of the hole along the sliding direction of the anchor is preferably at least 10% larger than the diameter of the screw. The hole may, for example, be a slot whose longitudinal direction is aligned along the sliding direction of the anchor.

The yoke parts and the permanent magnet (s) preferably form a magnetically conductive hollow body with an opening slot through which the armature can dive into the interior region of the hollow body.

In the closed position of the armature, the first armature-side abutment surface preferably lies on the outside of the outside of the hollow body and the second armature-side abutment surface on the inside of the hollow body.

It is also considered advantageous if the hollow body is tubular or channel-shaped and extends along a longitudinal axis which is aligned perpendicular to the predetermined sliding direction of the armature and the opening slot extends parallel to the longitudinal axis and the armature closes the opening slot. Preferably, the hollow body is at least partially closed at its front and rear tube or gutter end each with a metal sheet, preferably of magnetically non-conductive material.

The anchor is preferably a plunger anchor with a T-shaped cross-section.

The armature is preferably connected to a spring device which exerts a spring force in the direction of the open position of the armature in which the magnetic circuit is open.

The invention further relates to a method for mounting an electromagnetic drive for an electrical switch, in particular an electrical circuit breaker. According to the invention is provided with respect to such a method that the drive is pre-assembled and the magnetic circuit is then closed by the armature by the armature is brought into its closed position, the drive is brought into the Nachjustagezustand and self-adjustment of the position of the yoke parts to each other the magnetic force of the permanent magnet takes place and after the Selbstjustage the yoke parts are brought into a fixed state, in which the orientation of the yoke parts remains fixed regardless of the further positioning of the armature.

With regard to the advantages of the method according to the invention, reference is made to the above statements in connection with the electrical switch according to the invention, since the advantages of the method according to the invention essentially correspond to those of the electrical switch.

It is regarded as advantageous if, in the readjusted state, at least two yoke parts - driven by the magnetic force of the permanent magnet - are displaced relative to one another along the sliding direction of the armature until the yoke-side abutment surface of the first yoke part is self-aligned at a distance from the yoke-side abutment surface of the second yoke part which is identical to the distance between the first and the second armature-side abutment surface along the predetermined sliding direction.

According to a particularly preferred embodiment, it is provided that the drive is brought into the Nachjustagezustand by a screw connection between at least two relative to each other along the sliding direction of the armature in a predetermined range displaceable yoke parts is released, and after Selbstjustage the yoke parts are firmly screwed again.

Figur 1

ein Ausführungsbeispiel für eine Anordnung mit einem elektromagnetischen Antrieb sowie einem elektrischen Schalter, der mit dem elektromagnetischen Antrieb in Verbindung steht,

Figur 2

einen Tauchanker des elektromagnetischen Antriebs gemäß Figur 1 in einer geöffneten Position näher im Detail,

Figur 3

den Tauchanker gemäß Figur 2 in einer geschlossenen Position,

Figur 4

ein zweites Ausführungsbeispiel für einen elektromagnetischen Antrieb, bei dem der Tauchanker für den Hohlkörper, in den er eintauchen soll, geringfügig zu groß ist,

Figur 5

den Tauchanker gemäß Figur 4 nach einer Nachjustage des Antriebs,

Figur 6

ein Ausführungsbeispiel für einen erfindungsgemäßen elektromagnetischen Antrieb in einer dreidimensionalen Explosionszeichnung und

Figur 7

den elektromagnetischen Antrieb gemäß Figur 6 im montierten Zustand.

The invention will be explained in more detail with reference to embodiments; thereby show by way of example

FIG. 1

An embodiment of an arrangement with an electromagnetic drive and an electrical switch, which is in communication with the electromagnetic drive,

FIG. 2

a solenoid plunger of the electromagnetic drive according to FIG. 1 in an open position closer in detail,

FIG. 3

the plunger anchor according to FIG. 2 in a closed position,

FIG. 4

A second embodiment of an electromagnetic drive, wherein the plunger armature for the hollow body into which it is to dip, is slightly too large,

FIG. 5

the plunger anchor according to FIG. 4 after a readjustment of the drive,

FIG. 6

an embodiment of an electromagnetic drive according to the invention in a three-dimensional exploded view and

FIG. 7

according to the electromagnetic drive FIG. 6 in the assembled state.

For the sake of clarity, the same reference numbers are always used in the figures for identical or comparable components.

In the FIG. 1 can be seen an electromagnetic drive 10 for an electrical switch 20, which may be, for example, a circuit breaker. The electrical switch 20 comprises a movable switching contact 21 and a stationary switching contact 22.

The movable switching contact 21 is in communication with a drive rod 30 of the electromagnetic drive 10, which cooperates with a spring device 40 of the electromagnetic drive 10. To the spring device 40, a further drive rod 50 is also coupled, which is connected to a plunger armature 60 of the electromagnetic drive 10.

The plunger armature 60 can perform a stroke movement along a predetermined sliding direction P and thereby immerse in a magnetic hollow body 70 of the drive 10. FIG. 1 shows the plunger armature 60 with solid lines in an open position, in which it projects out of the hollow body 70. With dashed lines and with the reference numeral 61, the closed position of the plunger anchor is shown, in which it is completely inserted into the magnetic hollow body 70.

The function of the spring means 40 is the further drive rod 50 in the FIG. 1 to push upward, so that the plunger armature 60 is acted upon by a spring force, which should bring him to the open position. In the open position of the plunger armature 60, the movable switching contact 21 is in an open position, which in the FIG. 1 is shown by solid lines.

As will be explained in more detail below, by feeding a current through a coil 80 of the electromagnetic drive 10, a magnetic force can be generated with which the plunger armature 60 is brought against the spring force of the spring means 40 in its closed position. In this closed position, the plunger armature is held by the magnetic hollow body 70 even when no current is passed through the coil 80. The magnetic force required by the magnetic hollow body 70 to hold the plunger armature 60 in the closed position is generated by two permanent magnets 90 and 95 forming constituents of the magnetic hollow body 70. In addition to the two permanent magnets 90 and 95 includes the magnetic hollow body 70 in the embodiment according to FIG. 1 five yoke parts, namely a first yoke part 100, a second yoke part 105, a third yoke part 110, a fourth yoke part 115 and a fifth yoke part 120. The arrangement of the five yoke parts 100, 105, 110, 115 and 120 is selected such that the magnetic Hollow body 70 forms an opening slot 130 through which the cross-sectionally substantially T-shaped plunger armature 60 can dip into the hollow body. The five yoke parts 100, 105, 110, 115 and 120 are made of a magnetizable material, such as a ferrous material.

Once the plunger armature 60 has reached its closed position, press the two drive rods 30 and 50, the movable switching contact 21 in the FIG. 1 down, so that this also reaches its closed position and closes the electrical switch 20. The movable position of the switching contact 21 is in the FIG. 1 with dashed lines and the reference numeral 21a.

In the FIG. 1 In addition, it can be seen that the plunger armature 60 has a first armature-side abutment surface 62 and a second armature-side abutment surface 63. In the closed position of the plunger armature 60, the first armature-side abutment surface 62 rests on the outside 71 of the magnetic hollow body 70 or on the outside of the first yoke part 100 and the third yoke part 110. The second armature-side abutment surface 63 is in the closed position of the plunger armature 60 on the inside 72 of the hollow body 70, on the inside of the second yoke part 105, on.

At the closed position of the plunger armature 60, two magnetic circuits are closed whose magnetic flux is caused by the two permanent magnets 90 and 95. The magnetic flux of the first magnetic circuit flows back from the permanent magnet 90 via the fourth yoke part 115, the first yoke part 100, the plunger armature 60 and the second yoke part 105 to the permanent magnet 90. The magnetic flux of the second permanent magnet 95 flows through the fifth yoke part 120, the third yoke part 110, the diver anchor 60 and the second yoke part 105.

By the magnetic force of the two magnetic circuits, the plunger armature 60 is held in its closed position, although the spring force of the spring means 40 wants to bring the plunger armature 60 in the open position. The spring force of the spring device 40 is thus dimensioned smaller than the magnetic force of the magnetic circuits of the two permanent magnets 90 and 95th

If the electrical switch 20 is to be opened with the electromagnetic drive 10, so is by the coil 80 a Current is fed, which is opposite to the two magnetic circuits of the two permanent magnets 90 and 95. Characterized the magnetic holding force of the two magnetic circuits of the two permanent magnets 90 and 95 is lowered, so that the spring force of the spring means 40 is sufficient to push the plunger 60 in its open position. In the open position of the plunger armature 60, the distance between the first armature-side abutment surface 62 and the outer side 71 of the hollow body and the distance between the second armature-side abutment surface 63 and the inner side 72 of the hollow body is so large that the magnetic force of the permanent magnets 90 and 95 is no longer is sufficient to close the plunger armature 60 against the spring force of the spring device 40.

The FIG. 2 shows for a better overview the plunger armature 60 again in its open position in a larger view. It can be seen that the distance A2 between the first armature-side abutment surface 62 and the second armature-side abutment surface 63 corresponds to the distance A1 between the outer side of the first yoke part 100 and the inside of the second yoke part 105. For this reason, the two magnetic circuits of the two permanent magnets 90 and 95 gap-free, at least approximately gap-free, closed when the plunger armature 60 is fully inserted into the hollow body 70. This shows the closer FIG. 3 ,

In the FIG. 3 It can be seen that the first armature-side abutment surface 62 rests on the outside of the two yoke parts 100 and 110, and the two magnetic circuits M1 and M2 are closed at this point. In a corresponding manner, the two magnetic circuits M1 and M2 are also closed on the second armature-side abutment surface 63, because it rests completely on the inside of the second yoke part 105.

That in the FIG. 3 shown complete closing of the two magnetic circuits M1 and M2 is in the electromagnetic Drive 10 according to the FIGS. 1 to 3 only possible because the distance A1 between the two armature-side abutment surfaces 62 and 63 with the distance A2 between the outside of the two yoke parts 100 and 110 and the inside of the second yoke part 105 is identical.

In the embodiment according to the FIGS. 1 to 3 is preferably a Nachjustagemöglichkeit present, with which the position of the yoke parts is subsequently automatically relatively readjustable; the operation of such Nachjustagemöglichkeit will be explained below by way of example with reference to embodiments in which the length of the plunger armature 60 is not optimal.

The FIG. 4 shows a case where the distance A1 between the two armature-side abutment surfaces 62 and 63 is slightly larger than the distance A2. As can be seen here: $$\mathrm{A}\mathrm{1}=\mathrm{A}\mathrm{2}+\mathrm{d}\mathrm{x}\mathrm{,}$$

The length difference dx can be based on manufacturing tolerances in the production of the yoke parts, in particular the fourth yoke part 115 and the fifth yoke part 120, or on manufacturing tolerances in the manufacture of the plunger anchor 60.

In order to still ensure that the plunger armature 60 in its closed position, the two magnetic circuits M1 and M2 (see. FIG. 3 ), without having to bridge air gaps, is in the embodiment according to FIG. 4 in the fourth yoke part 115 as well as in the fifth yoke part 120 a Nachjustagemöglichkeit provided with the manufacturing tolerances can be corrected later.

In the FIG. 4 It can be seen that the fourth yoke part 115 and the fifth yoke part 120 each with holes 200 and 205 whose diameter d is slightly larger than the diameter of the associated fastening screws 210 and 215, which are screwed into the first yoke 100 and the third yoke 110 and hold the fourth yoke 115 and the fifth yoke 120 clamped. Due to the oversized size of the bores 200 and 205, it is now possible to subsequently correct the difference in length dx, namely by loosening the two fastening screws 210 and 215 in the closed position of the plunger armature 60. Due to the magnetic force of the two permanent magnets 90 and 95, the first yoke member 100 and the third yoke member 110 are pulled up so that they will abut with their outside on the first armature-side abutment surface 62. This exemplifies the FIG. 5 , The pulling up of the first yoke part 100 and the third yoke part 110 is based on the magnetic force of the two magnetic circuits M1 and M2, which always exert a magnetic force such that the magnetic circuit M1 or M2 is closed gap-free. The Indian FIG. 4 illustrated air gap between the plunger armature 62 and the two yoke parts 105 and 110 is thus thus closed by the magnetic force of the two permanent magnets 90 and 95 by the two yoke parts are pulled by the difference in length dx upwards.

The diameter d of the holes 200 and 205 along the sliding direction of the armature is preferably at least 10% greater than the diameter of the fastening screws 210 and 215. The bores 200 and 205 may be, for example, slots whose longitudinal direction aligned along the sliding direction of the armature is.

As soon as this self-adjustment, which is based on the magnetic force of the permanent magnets 90 and 95, is completed, the two fastening screws 210 and 215 can be tightened again so that the position of the first yoke part 100 and that of the third yoke part 110 relative to the fourth yoke part 115 and the fifth yoke part 120 is fixed again by clamping. After fixing, the distance between the two armature-side abutment surfaces 62 and 63 the distance between the outside of the two yoke parts 100 and 110 and the inside of the second yoke part 105th

In the FIG. 6 By way of example, the mechanical structure of an electromagnetic drive is shown in a three-dimensional exploded view. One recognizes the first yoke part 100, which is screwed to the fourth yoke part 115 by means of screws which are guided by oversized bores 200. Between the fourth yoke part 115 and the second yoke part 105 is the permanent magnet 90, which is fixed by means of two fastening plates 300 and 305 to the yoke parts. The two fixing plates 300 and 305 also fix the other permanent magnet 95, which is positioned between the second yoke part 105 and the fifth yoke part 120. At the fifth yoke part 120, the third yoke part 110 is fixed by means of fastening screws, which are guided by oversized bores 205.

As already explained, the holes 200 and 205 are slightly larger than the fastening screws used, so that it can come to an automatic readjustment when the plunger armature 60 is too large or too small dimensioned and occur in the closed position of the plunger armature unwanted air gaps. The plunger armature 60 is in the embodiment according to FIG. 6 formed by an upper anchor plate 64 and a guide plate 65 which are screwed onto an anchor central portion 66.

In the FIG. 6 can be seen beyond the further drive rod 50 which is passed through a bore 105a in the second yoke 105.

In the presentation according to FIG. 6 It can also be seen that the yoke parts 100, 105, 110, 115 and 120 and the two permanent magnets 90 and 95 form a hollow body which is tubular or channel-shaped and extends along a longitudinal axis L. The longitudinal axis L is perpendicular to the predetermined sliding direction P, with the plunger armature 60 performs its lifting movement. The front and rear Rohroder groove end of the tubular or channel-shaped hollow body is closed in each case with a sheet, of which one example in the FIG. 6 is shown and designated by the reference numeral 310.

The FIG. 7 shows the electromagnetic drive according to Figure 6 in the assembled state. It can be seen two sheets 310 and 320, which complete the tubular or channel-shaped hollow body 70 at the two pipe or gutter ends. In addition, one recognizes the further drive rod 50, which is led out of the hollow body 70 and with the spring means 40 according to FIG. 1 can be connected.

In addition, the fourth yoke member 115 and the second yoke member 105, the two mounting plates 300 and 305 and the coil 80 can be seen, which can protrude through recesses in the two sheets 310 and 320 from the hollow body 70. Also, the fastening screws 210 can be seen, with which the first yoke part is screwed to the fourth yoke part 115 such that an automatic readjustment, as has been described above, is possible.

Although the invention has been illustrated and described in detail by preferred embodiments, the invention is not limited by the disclosed examples.

LIST OF REFERENCE NUMBERS

10

electromagnetic drive

20

electrical switch

21

movable switching contact

21a

movable position

22

fixed switching contact

30

drive rod

40

spring means

50

drive rod

60

plunger

61

closed position of the plunger anchor

62

first anchor-sided stop surface

63

second anchor-side stop surface

64

anchor plate

65

guide plate

66

Anchor midsection

70

hollow body

71

outside

72

inside

80

Kitchen sink

90

permanent magnet

95

permanent magnet

100

first yoke part

105

second yoke part

105a

drilling

110

third yoke part

115

fourth yoke part

120

fifth yoke part

130

opening slot

200

drilling

205

drilling

210

fixing screw

215

fixing screw

300

mounting plate

305

mounting plate

310

sheet

320

sheet

A1

distance

A2

distance

d

diameter

dx

length difference

L

longitudinal axis

M1

magnetic circle

M2

magnetic circle

P

sliding direction

Claims (9)

1. Electromagnetic drive (10) for an electrical switch (20), in particular an electrical circuit breaker, with

   - at least one movable armature (60), which can implement a lifting movement along a predetermined pushing direction (P), can be connected indirectly or directly to a movable switching contact (21) of the switch (20), and, in a closed position (61), closes a magnetic circuit (M1, M2) of the drive (10) at a first armature-side stop face (62) with a first magnetically conductive yoke part (100) of the drive (10) and at a second armature-side stop face (63) with a second magnetically conductive yoke part (105) of the drive (10),

   - at least one permanent magnet (90, 95), which produces a magnetic field for the magnetic circuit (M1, M2) and a holding force for holding the armature (60) in the closed position (61), and

   - at least one coil (80), which is arranged in such a way that a magnetic flux can be brought about by a current flow through the coil (80), which magnetic flux is directed in the same direction as or in opposition to the magnetic flux of the permanent magnet (90, 95) in the magnetic circuit (M1, M2),

   - wherein the electromagnetic drive (10) provides the possibility of a readjustment state after installation by virtue of self-adjustment of the position of the first yoke part (100) and the second yoke part (105) relative to one another being possible as a result of the magnetic force of the permanent magnet (90, 95), and

   - wherein the yoke parts (100, 105) can be brought into a fixedly installed state, in which the alignment of the yoke parts (100, 105) is fixed independently of the further positioning of the armature (60), wherein

   - in the readjustment state, the magnetic circuit (M1, M2) is closed by the armature (60) and at least two yoke parts (100, 105) of the drive (10) can be displaced relative to one another along the pushing direction (P) of the armature (60), so - driven by the magnetic force of the permanent magnet (90, 95) - the yoke-side stop face of the first yoke part (100) is brought in a self-adjusting manner to a spacing (A2) from the yoke-side stop face of the second yoke part (105) which is identical to the spacing (A1) between the first (62) and the second armature-side stop face (63) along the predetermined pushing direction (P),
   characterised in that

   - the at least two yoke parts (100, 105), which can be displaced relative to one another along the pushing direction (P) of the armature (60), are screwed together, wherein one screw (210, 215) is led through a hole in one of the two yoke parts (100, 105) and is screwed to the other of the two yoke parts (100, 105), wherein the diameter (d) of the hole along the pushing direction (P) of the armature (60) is greater than the diameter (d) of the screw (210, 215),

   - wherein, with a loose screw connection and closed position (61) of the armature (60), the yoke parts (100, 105) are in the readjustment state and

   - wherein, with a tight screw connection, the yoke parts (100, 105) are in a fixedly installed state.
2. Electromagnetic drive (10) according to claim 1,
   characterised in that
   the yoke parts (100, 105) and the permanent magnet(s) (90, 95) form a magnetically conductive hollow body (70) with an opening slit (130) through which the armature (60) can plunge into the interior of the hollow body (70).
3. Electromagnetic drive (10) according to claim 2,
   characterised in that
   in the closed position (61) of the armature (60) the first armature-side stop face (62) rests externally on the outer side (71) of the hollow body (70) and the second armature-side stop face (63) rests inwardly on the inner side (72) of the hollow body (70).
4. Electromagnetic drive (10) according to any one of the preceding claims,
   characterised in that

   - the hollow body (70) is tubular or channel-shaped and extends along a longitudinal axis (L) which is oriented perpendicularly to the predetermined pushing direction (P) of the armature (60),

   - at its leading and trailing tubular or channel end the hollow body (70) is in each case closed, at least in certain sections, by a metal sheet (310, 320),

   - the opening slit (130) extends parallel to the longitudinal axis (L) and

   - the armature (60) closes the opening slit (130).
5. Electromagnetic drive (10) according to any one of the preceding claims,
   characterised in that
   the armature (60) is a plunger armature with a T-shaped cross-section.
6. Electromagnetic drive (10) according to any one of the preceding claims,
   characterised in that
   the armature (60) is connected to a spring device (40), which exerts a spring force in the direction of the open position of the armature (60), in which the magnetic circuit (M1, M2) is opened.
7. Method for installing an electromagnetic drive (10) according to any one of the preceding claims for an electrical switch (20), in particular an electrical circuit breaker,
   characterised in that

   - the drive (10) is pre-installed and the magnetic circuit (M1, M2) is then closed by the armature (60) in that the armature (60) is brought into its closed position (61),

   - the drive (10) is brought into the readjustment state and self-adjustment of the position of the yoke parts (100, 105) relative to one another occurs due to the magnetic force of the permanent magnet (90, 95), and

   - after self-adjustment the yoke parts (100, 105) are brought into a fixedly installed state in which the alignment of the yoke parts (100, 105) remains fixed independently of the further positioning of the armature (60).
8. Method according to claim 7,
   characterised in that
   in the readjustment state at least two yoke parts (100, 105)

   - driven by the magnetic force of the permanent magnet (90, 95) are displaced relative to one another along the pushing direction (P) of the armature (60) until the yoke-side stop face of the first yoke part (100) has been brought in a self-adjusting manner to a spacing (A2) from the yoke-side stop face of the second yoke part (105), which spacing is identical to the spacing (A1) between the first (62) and second armature-side stop face (63) along the predetermined pushing direction (P).
9. Method according to claim 8,
   characterised in that

   - the drive (10) is brought into the readjustment state by loosening a screw connection between at least two yoke parts (100, 105) which can be displaced relative to one another, within a predetermined region, along the pushing direction (P) of the armature (60), and

   - after self-adjustment the yoke parts (100, 105) are screwed tight again.

Images