EP2301047B1 - Solenoid arrangement and valve arrangement - Google Patents

Description

The invention relates to a solenoid assembly according to the preamble of claim 1. The invention further relates to a valve assembly.

The generic Hubmagnetanordnung is widely used as a drive for actuating hydraulic or pneumatic valves in fluid technology.

Actuating solenoids for fluid technology are usually modular and have a liquid-tight pole tube, with the exception of a passage opening for the plunger, in which the armature is movably guided. On the pole tube, a bobbin is mounted. The bobbin is fastened with a nut. Between a Polkernabschnitt and a pipe section of the pole tube is usually a separator ring of non-magnetic material welded. As a result, the magnetic field lines in the pole tube pass from the pole core section to the armature. Only in this way can a working air gap filled with field lines be formed.

Especially with switching valves used as simple as possible lifting solenoids. For example, German patent application no. 10 2008 030 748 the Applicant a pole tube, which has a reduced material thickness to produce the required between the pole core and pipe section discontinuity in the region of the transition section. Here, in favor of the simpler production of the pole tube, a magnetic tributary flow through the transition region is accepted. These pile tubes are also referred to as thin-rolled pile tubes, since the reduction of the material thickness is usually achieved by twisting off. However, this requires a - im Compared to the usable magnetic flux guided through the working air gap - considerable tributary. It is believed that a loss of power of the solenoid of about 10% when a thin-twisted pole tube is used instead of a conventional pole tube, assuming identical coil power. In addition, solenoids with thin-rolled pile tubes often have a very unfavorable for the valve actuation force-stroke characteristic, such as the characteristic curve 42 of a conventional lifting magnet in FIG. 3 shows. The actuation force increases only shortly before the attachment of the armature to the pole core significantly. However, a fluidic valve needs a sufficient actuation force over a larger stroke range.

The US 2006/0043326 A1 shows an ABS valve with a spherical anchor. The armature is movably guided in a pipe section, which passes over a section with a very small cross section in a pole core. The pole core has on its inner bottom a cone-shaped elevation, in which a shell is sunken for receiving the spherical anchor. The anchor also serves as a valve member. Due to this contour of the Polkernbodens the lifting force in the pole near the area is greatly increased, since the permeated by magnetic field lines volume with the movement of the armature, especially in the pole near the area quickly reduced.

It is the object of the present invention to provide an improved Hubmagnetanordnung, which has in particular a suitable for the valve actuation characteristic.

This object is achieved by a solenoid arrangement with the features of patent claim 1.

The invention is generally based thereon, in a lifting magnet in which a magnetic discontinuity in the pole tube is formed by reducing the effective material thickness - eg a reduction in the thickness, in particular the wall thickness of the magnetically active material -, the Polkernabschnitt facing the front side of the armature and a in the Interior of the pole tube provided on the pole core portion bottom each having a contour which have a mutual axial overlap. This allows for low production costs an advantageous effect on the force-stroke curve of the solenoid.

The said contours are according to the invention collar-shaped and cone-shaped elevations. The respective counter contour has geometrically corresponding depressions.

Particularly preferred is an embodiment according to claim 2, wherein the transition portion between Polkernabschnitt and pipe section of the pole tube has a reduced wall thickness. In addition, a step is formed at the anchor by means of a projecting collar. The bottom surface at the pole core portion is also stepped by a cylindrical depression. The collar of the anchor is receivable in the recess, in the sense that at least a portion of the collar dips into the depression when the anchor abuts the ground surface.

In this way, the force-stroke characteristic of the Hubmagnetanordnung can be designed so that a sufficient actuation force is available in a larger range of the characteristic. The magnetic field lines focus more on the area between the armature and the bottom surface of the Polkernabschnitts by the construction according to the invention. On the way of the armature from its polkernabseitigen end position to immersion of the collar in the depression is thus a high operating force available. The actuating force increases significantly shortly before the immersion of the collar in the depression. After immersion, the actuation force drops. On the remaining way of the anchor stroke to concerns on the ground surface is a moderate operating force available. Due to the reduced actuation force on the last stroke section, the mechanical load of the pole tube and a possibly existing between anchor and Polkernabschnitt anti-sling disc is reduced. In addition, better shutdown times are achieved.

By means of the solenoid assembly according to the invention can be valves that usually require high actuation forces already at the beginning of an opening operation of the valve slide, safely control or switch through. By already existing on a polkernfernen section of the hub high actuation force, a relatively weakly dimensioned coil can be used. The power requirement for the operation is reduced compared to conventional solenoids. In addition, it is now possible to provide a lifting magnet arrangement which, even when using thin-rolled pile tubes, has a precisely defined characteristic which is largely independent of production-related tolerances. In this application, the term thin-twisted pole tube is used for the sake of simplicity. However, this term should generally refer to Hubmagnetanordnungen with a pole tube, which has a reduced wall thickness in the transition section between pole core and pipe section. The reduced wall thickness can be generated not only by turning but also by other processes. Examples include rolling, swaging, stretching a rod-shaped semi-finished or molding a ring of non-magnetic material, as in the aforementioned German patent application 10 2008 030 748 the applicant described. All these methods for reducing the wall thickness in the transition section should be encompassed by the term "thin-twisted pole tube".

The object is likewise achieved by a valve arrangement which is equipped with such a lifting magnet arrangement. By matching the contours, in particular the length of the collar and possibly the length of a collar on Polkernabschnitt the force-stroke curve of the Hubmagnetanordnung can be optimally adapted to the operating force requirements of the valve assembly.

Advantageous embodiments of the present invention are specified in the subclaims.

The said contours can have a wide variety of shapes. Suitable are e.g. collar-shaped, annular and conical elevations. These need not necessarily be concentric with the axis of movement of the armature, but the concentric shape facilitates manufacture. The respective counter contour has according to the invention geometrically corresponding depressions.

Preferably, as stated, the pole core portion, the transition portion and the pipe portion of the pole tube are integrally formed of a magnetizable material. This allows a particularly cost-effective production of the pole tube. The production is particularly simple if the transition section has a radial groove in an outer surface of the pole tube. The transitions from the radial groove to the pole core section or from the radial groove to the pipe section may be rounded in order to prevent cracking.

The collar can be made slightly shorter than a collar portion of the pole core. As a result, the small force increase caused by the collar section can be utilized in the section of the characteristic that is remote from the pole core.

According to a preferred embodiment of the present invention, a radial gap between the collar and the recess is dimensioned such that a movement of the armature is fluidically damped in an end position associated with the pole core section. As a result, the mechanical load of the pole tube and, if necessary, an inserted between the armature and Polkernabschnitt anti-adhesive is reduced.

According to a particularly preferred embodiment of the present invention, a first position of the armature, wherein the end face of the armature facing a polkernkernseitigen end of the transition section, and / or a second position of the armature, wherein an end face of the collar of the armature of the bottom surface of the Polkernabschnitts facing arranged according to an expected force profile of acting on an opening operation on the valve spool flow forces.

Preferably, the second position of the armature corresponds to a nearly completely open control cross section. At this point, the flow-related restoring forces on the valve spool. The reduced from the immersion of the collar in the depression actuation forces are still sufficient to turn on the valve full.

Figur 1

zeigt eine Hubmagnetanordnung gemäß der vorliegenden Erfindung mit einem an einen Ventilgehäuse befestigten Polrohr, mit einem auf dem Polrohr aufsitzenden Spulenkörper und mit einem den Spulenkörper umschließendes Gehäuse,

Figur 2

zeigt einen Schnitt durch das Polrohr der in Figur 1 dargestellten Hubmagnetanordnung und

Figur 3

zeigt eine Kraft-Hub-Kennlinie der erfindungsgemäßen Hubmagnetanordnung im Vergleich zu einer Kraft-Hub-Kennlinie eines herkömmlichen Hubmagneten.

Hereinafter, the present invention and its advantages will be explained in more detail with reference to the embodiment shown in the figures.

FIG. 1

shows a Hubmagnetanordnung according to the present invention with a pole tube attached to a valve housing, with a seated on the pole tube bobbin and with a coil body surrounding housing,

FIG. 2

shows a section through the pole tube of in FIG. 1 illustrated Hubmagnetanordnung and

FIG. 3

shows a force-stroke characteristic of the Hubmagnetanordnung invention compared to a force-stroke curve of a conventional solenoid.

The FIG. 1 shows the typical structure of a solenoid 1, as it is used for the actuation of switching valves of fluid technology. On a valve housing 3, a pole tube 5 of the solenoid 1 is screwed into the valve bore. On the pole tube 5, a magnetic coil 7 is attached. The solenoid 7 is secured by means of a nut 9 on the pole tube 5. At a transition section 14, the pole tube 5 is constricted in terms of its outer radius.

The structure of the pole tube 5 and the guided therein anchor according to the present invention illustrates the FIG. 2 , A pole tube body 11 is made of a ferromagnetic steel, for example, from a bar stock by machining in the illustrated form.

The pole tube body 11 is divided axially into a pole core 12, a transition section 14 and a pipe section 16. The overall bush-like shape of the pole tube body 11 allows the insertion of an armature 20 in a central bore 18. The bore 18 is at its end remote from the pole section 12 at the opening of the pipe section 16 later with a closure piece - also called stroke limitation - (not shown), which simultaneously carries a thread for fixing the nut 9.

From the pole core 12 is an annular cone-shaped collar 22 before. This goes over a rounding 24 in the transition section 14. In comparison to the pole core 12 and the pipe section 16, the outer peripheral surface of the pole tube 5 is constricted at the transition section 14 by a radial groove. About a further rounding 24 and an inclined eccentric outer surface of the transition section 14 is in the pipe section 16 via.

In the bore 18, the armature 20 is mounted axially displaceable. In the working air gap between the armature 20 and the pole core 12 an anti-stick washer 26 is inserted.

The armature 20 is contoured on its end facing the pole core 12 by a step: From the annular end face 28 is a cylindrical collar 30 before.

In the bottom surface 32 of the bore 18, a recess 34 is present which corresponds geometrically with the collar 30. This means that the collar 30 can dip into the recess 34. The axial extent of the collar 30 and its radial extent is chosen with respect to the desired characteristic shape, as will be explained later. The depth of the recess 34 is chosen so that, taking into account the anti-slump disc 26 is still a gap between the bottom of the recess 34 and the end face of the collar 30 when the armature 20 is in its polkernseitigen end position.

The FIG. 3 shows the force-stroke curve 40 of the solenoid assembly 1 according to the invention in comparison with the force-stroke curve 42 of a conventional Hubmagnetanordnung, although a thin twisted pole tube, but no contouring of the polkernseitigen anchor end face or the bottom of the bore 18 on the pole core 12 has ,

In the lifting magnet arrangement 1 according to the invention, as the characteristic curve 40 shows with respect to the characteristic curve 42, an increased increase in the actuating force could be achieved in an early section 40a of the lifting operation. In this case, the armature 20 still has a large distance from the pole core 12. The contours of anchor end face and bottom surface of the pole core 12, ie collar 30 and recess 34, are not yet in axial overlap.

The characteristic curve 40 increases further as the armature 20 approaches the pole core 12, in order to form a plateau in the section 40b. The portion 40b corresponds to a position of the armature 20, in which the collar 30 is just in front of the bottom surface 32, so not yet immersed in the recess 34.

With the formation of an axial overlap, in this example when immersing the collar 30 in the recess 34, the characteristic curve 40 decreases in section 40c first. When the armature 20 abuts the pole core 12, the characteristic curve 40 finally increases moderately and ends with the holding force 40d, but does not exceed the plateau reached in section 40b.

The influence of the annular cone-shaped collar 22 on the characteristic 40 and also on the characteristic 42 is marginal. In the stroke area 44, at most a minimal bulge in the characteristic 42 can be recognized. The characteristic increase in the characteristic curve 40 achieved by the contouring of the armature 20 and of the bottom on the pole core 12 far exceeds an influence of the annular cone-shaped collar 22.

By adjusting the axial extent of the collar 30, the position of the plateau portion 40b of the characteristic curve 40 can be varied. The radial extent of the collar 30 and the size of the radial gap between collar 30 and recess 34 have an influence on the height of the plateau or on the different degrees of expression of the characteristic curve of the characteristic 40 relative to the Characteristic 42. The air gap remaining at the pole core 12 in the end position of the armature 20 to the bottom of the depression 34 has an influence on the holding force 40d. In particular, the described adjustments of the anchor contour and the bottom contour, the characteristic curve 40 is tuned to the operating force characteristic of a fluidic valve, that an area in which high actuation forces are required - eg from the beginning of the opening of a fluid path in the valve up to its complete opening - approximately coincide with the plateau 40b. Thus, in particular, flow forces which act in the closing direction of the valve can be safely overcome and the valve slide can be switched through from each actuation state.

Particularly in the case of proportional valves, in which the position of the valve slide is controlled by the actuating force provided by the lifting magnet 1 acting against a spring, the characteristic line 40 falling in the region 40c is advantageous. It results in there on the position axis very narrow cutting area between the spring characteristic and the force-stroke curve 40. The desired position of the valve spool can thus be controlled very accurately and with little scatter by the energization of the solenoid 1.

The invention is generally based thereon, in a lifting magnet in which a magnetic discontinuity in the pole tube is formed by reducing the effective material thickness - eg a reduction in the thickness, in particular the wall thickness of the magnetically active material -, the Polkernabschnitt facing the front side of the armature and a in the Interior of the pole tube provided on the pole core portion bottom each having a contour which allow a mutual axial overlap. This allows for low production costs an advantageous effect on the force-stroke curve of the solenoid.

reference numeral

1

solenoid

3

valve housing

5

pole tube

7

solenoid

9

mother

11

Polrohrkörper

12

pole core

14

Transition section

16

pipe section

18

drilling

20

anchor

22

collar

24

curve

26

anti-adhesion disc

28

Annular face

30

Federation

32

floor area

34

depression

40

Force-stroke characteristic

40a

Characteristic section

40b

Characteristic section

40c

Characteristic section

40d

holding force

42

Force-stroke characteristic

44

Stroke range

Claims (10)

1. Solenoid arrangement comprising
   a pole tube (5) which is axially made up of a pole core section (12), a transition section (14) and a tube section (16), with the transition section (14) having a lower effective material strength than the tube section (16) in order to generate a magnetic discontinuity in the pole tube, and
   an armature (20) which is guided in a movable manner in the pole tube, with an end face of the armature (20) which faces the pole core section (12) and a base (32, 34) which is provided in the interior of the pole tube (5) on the pole core section (12) in each case having a contour, these contours overlapping in the axial direction,
   characterized in that
   one of the contours has a single-stage or multi-stage collar (30) or a cone, and in that the respectively other contour has a recess (34) which corresponds to the shape of the collar (30) or the cone.
2. Solenoid arrangement according to Claim 1,
   with the transition section (14) having a lower wall thickness than the tube section (16),
   the armature (20) having a collar (30), which projects axially from an end surface (28), at its end face which faces the pole core section (12),
   there being a cylindrical recess (34) in a base surface of the pole core section (12) which faces the armature (20), and
   it being possible for the collar (30) of the armature (20) to be accommodated in the recess (34).
3. Solenoid arrangement according to Claim 2, characterized in that the pole core section (12), the transition section (14) and the tube section (16) are integrally formed from a magnetized material.
4. Solenoid arrangement according to Claim 2 or 3, characterized in that the pole core section (12) has, starting from the base surface, an annular flange section (22), in particular a flange section in the form of an annular cone, the transition section (14) adjoining said flange section with an equal wall thickness, and in that an axial size of the flange section (22) exceeds an axial size of the collar (30).
5. Solenoid arrangement according to one of the preceding Claims 2 to 4, characterized in that the transition section (14) has a radial groove in an outer surface of the pole tube (5).
6. Solenoid arrangement according to Claim 5, characterized in that the transitions from the radial groove to the pole core section (12) or from the radial groove to the tube section (16) are rounded.
7. Solenoid arrangement according to one of the preceding Claims 2 to 6, characterized in that a radial gap between the collar (30) and the recess (34) is of such a size that a movement of the armature (20) into an end position which is associated with the pole core section (12) is fluidically damped.
8. Valve arrangement having a housing (3), having a valve slide which is guided such that it can move in a valve bore inside the housing (3) and by means of which a control cross section of a fluid connection can be adjusted, and having a solenoid arrangement (1) according to one of Claims 1 to 7 which is intended to operate the valve slide.
9. Valve arrangement according to Claim 8, characterized in that a first position of the armature (20), in which first position the end surface (28) of the armature (20) is situated opposite an end of the transition section (14) which is on the pole core section side, and/or in that a second position of the armature (20), in which second position an end surface of the collar (30) of the armature (20) is situated opposite the base surface (32) of the pole core section (12), are/is arranged in accordance with an expected force profile of flow forces which act on the valve slide in the event of an opening process.
10. Valve arrangement according to Claim 9, characterized in that the second position of the armature (20) corresponds to a virtually completely open control cross section.

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