DE19646446A1 - Electric adjustable valve with valve slide spring-loaded in zero setting - Google Patents

Abstract

The valve has a slider (6), which is spring loaded in its zero setting by springs (12,14), and is movable into the working position using solenoids (8,10). The valve slider can be brought into the working position by the simultaneous control of two solenoids (8, 10) working against the force of spring. Both valve slider sides are acted on by the springs and the solenoid. Each spring acts on the side of an armature (20,21) of the solenoid facing away from the valve slider.

Description

The invention relates to an electrically adjustable Valve arrangement according to the preamble of the claim 1.

In mobile hydraulics in particular, efforts are being made to the valve arrangements for controlling consumers, for example single or double-acting lifting cylinders to be as compact as possible. Often the hydrau lik components in disc design, so that meh rere discs, for example valve discs to a ge common control block are put together. The single ones Valve disks serve as housings to accommodate Wegeven til, switching valve and pilot valve spools etc., each because actuated directly or by means of pilot valves the.

In the construction of the valve assemblies, ver seeks the number of Ka to be incorporated into the slices channels to a minimum so that the ferti engineering expenditure in the manufacture and processing of the cast blank for the disc is reduced. For this For this reason it is often preferred to use the valve spool Actuate valve arrangement directly via electromagnets and not through pilot valves, the control lines of which Incorporation of additional channels in the cast blank request, while with direct actuation only recording holes for fastening the electromagnets and for through guidance of the plunger must be provided.

The valve spools are usually in cross holes of the valve disc, which is in the narrow side surfaces the valve disc open, so that the electromagnets in  these narrow sides have to be screwed in. The elec tromagnets must therefore be chosen so that they still can be screwed into these narrow sides.

In some applications it can happen that Be actuation of the valve accommodated in the valve disk slide comparatively high switching capacities required are, so that electromagnets with corresponding Lei stungen must be used. Such electromagnets with increased performance usually have comparative wise large outer dimensions, so that their attachment frets are too large to fit into the narrow to be screwed in. An increase the switching capacity by increasing the electromagnets is therefore limited by the effective slice thickness.

In contrast, the invention is based on the object to create a valve assembly with minimal Installation space an increased switching capacity can be applied.

This task is accomplished through the features of the patent spell 1 solved.

By taking the valve spool on at least one egg to apply a spring to the end face and deswei tere on each of the two valve spool ends Providing electromagnets can increase the switching capacity be without additional space in the thickness direction of the Valve disc is needed. This is accomplished by both electromagnets are energized simultaneously, so that one compensates the spring force and the force of the white tere electromagnet practically completely different exercise of the valve spool is used.

In valve arrangements, the valve spool from the Zero position is only shifted in one direction, it is usually sufficient if the valve slide over  a spring is biased to its zero position while Both ends can be loaded with the electromagnets are. To create the same direction of action, ei One end of a pulling electromagnet and the other Ren end face an impacting electromagnet provided the. However, it is also possible to use one of the electromagnets to couple via a deflection device so that both elec tromagnets are designed for example as a solenoid can.

It when the spring (s) on the Back of the (assigned) anchor acts so that this anchor ge over the spring against the valve spool is pressed. With appropriate energization of the electroma The spring can be tensioned by the anchor, so that the force of the other electromagnet to the valve slide can be used. Through this further The anchors do not have to be attached to the valve slide as no tensile forces are transmitted to it have to.

In valve arrangements with a valve spool that is off a zero position in the first and second position lungs is displaceable, are advantageous both valve spool end faces each with a spring and charged with a double solenoid, which is both in can be both pushing and pulling. At In this variant for a so-called three-position valve, the acted on two double stroke magnets so that both in Sliding direction of the valve spool act so that the Power of a double solenoid to compensate for the force the spring acting in the opposite direction is used rend the other double solenoid together with the other Spring causes the valve spool to move. This construction allows the switching capacity to be reduced the control of valve arrangements in disc design  with practically the same installation space with minimal increase directional effort.

Instead of a double solenoid, two dimensions gnete with opposite direction of action coaxially behind are switched, the anchor of which via a ver binding, for example a tie rod connected to each other they are.

In principle, the device according to the invention Proportional magnets and switching magnets can be used.

To set an exact zero position, the Valve slide associated with other centering springs the, about the possible deviation of the spring rate or the preload of the two act on the end faces the springs are balanced. The spring rate of the centering feather is much less than that of the two Fe other.

By supporting the spring (s) on one spring part each ler who acts on the valve spool and in the zero rests on the housing, acts upon an axial movement of the Valve spool only one of the springs against the assigned anchor while the other spring on the housing is supported so that the valve spool movement alone caused by the force transmitted through the other anchor becomes.

Other advantageous developments of the invention are the subject of further subclaims.

A preferred embodiment of the invention in the following with reference to schematic drawings tert. Show it:  

Fig. 1 is a schematic diagram of a Venti lanordnung invention in a zero position of the valve slide bers;

Fig. 2 is an illustration of the valve assembly of Fig. 1 with energized electromagnet and

Fig. 3 spring characteristics of springs for acting on the valve spool in FIG. 1.

Fig. 1 shows a schematic view of a Venti lanordnung 1 , which is formed for example in a valve disc egg nes control block. For this purpose, in the space formed by the valve disc valve housing 2 is tion 4 formed on a valve spool 6 is a Aufnahmeboh which is axially displaceably guided in the receiving bore. 4 The Ven tilschieber 6 is biased by two electromagnet assemblies 8 , 10 and two springs 12 , 14 in its zero position shown in Fig. 1.

Each valve arrangement 8 , 10 is designed as a double lifting magnet in the embodiment shown and has two coaxial coils 16 , 18 and 17 , 19 which surround a common armature 20 and 21 , respectively.

The coil formers 16 , 18 ; 17 , 19 can be acted upon with current such that, for example, the inner coil body 18 ( 19 ) acts on the armature in the abutting direction, ie towards the valve slide 6 , while the outer coil body 16 ( 17 ) pulls the armature 20 in a pulling direction, ie applied away from the valve slide 6 . The armature 20 , 21 is arranged between the coil bodies 16 , 18 and 19 , 17 , so that the armature 20 ( 21 ) from the zero position ( FIG. 1) by energizing the coil body 16 ( 19 ) or the coil body 18th ( 17 ) is movable.

Each armature 20, 21 has a plunger 22 which is secured to the spool 6, so that the plunger 22 also can act in zie budding toward the valve spool. 6

In the design principle shown in Fig. 1, the two springs 12 , 14 each act on the back of the armature 20 , 21 facing away from the valve slide 6 , so that their biasing forces are transmitted to the valve slide 6 via the plunger 22 .

As is apparent from Fig. 3, the characteristic of the two springs 12 , 14 is chosen to be relatively flat (low spring rate), so that the spring forces ΔF experience a comparatively small change when the valve slide 6 is displaced. This flat spring characteristic ensures that the spring forces ΔF ₂ acting on them have approximately the same level both in the zero position ( FIG. 1) and in the deflection position (ΔS ₂ in FIG. 3). In the case of a steep spring characteristic line (left in FIG. 3), with the same deflection ΔS _1, a considerably larger force ΔF _{1 would act} on the valve slide 6 .

In valve arrangements with conventional nominal sizes, for example NG6, NG10, the preload of the two springs 12 , 14 can be selected, for example, with 50 N. The electromagnets 8 , 10 then have to bring appropriate forces.

As can further be seen from Fig. 1, the valve slide 6 is in addition to the springs 12 , 14 still biased by two Zen trier springs 24 , 26 in its zero position, which are supported on the one hand on the housing of the electromagnet 8 , 10 and on the other hand via a spring plate 28 or 30 act on the valve slide 6 . In the zero position shown, the spring plates 28 , 30 rest against the valve housing 2 with radial flanges. By these two centering springs 24 , 26 any deviations in the bias or in the spring characteristic of the two springs 12 , 14 Chen Chen, so that the valve spool 6 is always biased exactly to its zero position.

Instead of the centering springs 24 , 26 , an adjusting device (not shown) for adjusting the pretension of the springs 12 , 14 could also be used. Of course, both variants can also be used side by side in parallel.

Depending on the application, the double-stroke magnets 8 , 10 can be proportional magnets or switching magnets.

Instead of the double-stroke magnets 8 , 10 indicated in FIG. 1, two electromagnets can also be connected coaxially one behind the other, the armatures of which are connected to one another. One of these bobbins must then have an effect in the butt direction, while the other bobbin acts on the armature in the pulling direction.

When energizing, for example, the bobbin 17 and 18 , the armature 21 is acted upon by the bobbin 17 in the pulling direction, ie toward the spring 14 and the armature 20 through the bobbin 18 in the abutting direction, ie toward the valve spool 6 , so that the valve spool 6 is shifted to the right (view according to FIG. 2). Here, only the plunger 22 of the armature 20 acts directly on the valve slide 6 , while the armature 21 acts on the spring 14 to compress it. That is, the pulling direction (away from the valve spool 6 ) acting anchor does not transmit tensile forces to the valve spool 6 but relieves it only by compressing the spring 14 , so that no mechanical connection between armature 20 , 21 and valve spool 6 is required.

The forces that can be applied by the electromagnets 8 , 10 and the spring rates and preloads of the springs 12 , 14 are coordinated with one another in such a way that the electromagnet 10, or more precisely the coil body 17 and the armature 21, compensate for the force of the spring 14 acting in the opposite direction (ΣF = 0), so that the actuating force acting on the valve slide 6 is determined by the forces acting on the armature 20 from the spring 12 and the coil former 18 (F _spring + F _{magnet 8} ).

With this new construction, it can practically double switching capacity compared to conventional elec tromagneten be applied without a larger elec tromagnet must be used. It can thus valve Use slices with a comparatively small slice thickness find.

During the displacement of the valve spool as shown in FIG. 2, the spring plate 30 is lifted from its supporting position and the centering spring 26 tensioned, while the other Zen trier spring 24 no effect is exhibited, since the spring plate 28 remains in its supporting position and the tension of the spring 24 remains constant. Since the spring rate of the springs 24 and 26 is comparatively low, the force of the electromagnet can be used almost completely for valve adjustment.

The displacement of the valve spool 6 in the opposite direction (left in Fig. 2) is carried out accordingly by Be flow of the bobbin 16 and 19 of the electromagnets 8 and 10 , so that the double-stroke magnet 8 acts against the force of the spring 12 , while the valve spool 6 by the force of the spring 14 and the double solenoid 10 is applied in the direction of displacement.

In principle, the valve arrangement according to the invention use for secondary functions on work machines,  that do not conduct maximum volume flows and those that do not Auxiliary functions, such as locking the valve position lungs, automatic unlocking, leak oil-free sealing etc. are executed. The preferred application of Valve arrangements according to the invention should be in the Automa Movement sequences using standard valves lie above the small and medium hydraulic fluid volume currents are switched.

As already mentioned at the beginning, the application is not limited to three-position valves, but valve arrangements with a zero position and one or more first working positions can also be used, in which the valve slide is only displaced in one direction from the zero position. In such an application, it is sufficient if a commercially available electric magnet is arranged on both sides, both of which act in the same direction on the valve spool, so that an electromagnet compensates for the Fe and the other causes the axial displacement. One or more springs can be provided to bias the valve spool into its zero stop position. The springs 12 , 14 can act on Federtel ler (dash-dotted lines in Fig. 1 right) on the armature 20 , 21 , so that these (like the spring plate 28 , 30 ) are supported in the zero position on the (magnet) housing. When moving the valve spool one of the spring plates is lifted and the associated spring is compressed, while the other spring plate remains in its support position. The assigned spring does not act on the valve spool in the direction of displacement.

An electrically adjustable valve arrangement is disclosed tion, the valve spool via electromagnets in its ar working position is displaceable. It affects both Face of the valve spool two electromagnets in the same direction, so through one of these electromagnets the force of a bias spring is compensated for  through the other electromagnet the axial movement of the Ven tilschiebers takes place. In this way, ver using conventional magnets, the switching capacity practically ver double, so that in valve arrangements in disc design no increase in slice thickness due to larger Electromagnet is required.

Claims (11)

1. Electrically adjustable valve assembly with a valve spool ( 6 ) which is biased by spring preload in its zero position and by means of egg NES electromagnet ( 8 , 10 ) can be moved into a working position, characterized in that the valve spool ( 6 ) by simultaneous activation of two against the force of a spring ( 12 , 14 ) we kend electromagnets ( 8 , 10 ) can be brought into the working position. 2. Valve arrangement according to claim 1, characterized in that both valve spool sides with a spring ( 12 , 14 ) and an electroma gneten ( 8 , 10 ) are acted upon. 3. Valve arrangement according to claim 1 or 2, characterized in that each spring acts on the side facing away from the valve slide ( 6 ) of an armature ( 16-19 ) of the electromagnets ( 8 , 10 ). 4. Valve arrangement according to one of the claims 1 to 3, characterized in that both electromagnets ( 8 , 10 ) are lifting magnets, an electromagnet acting via a deflection device on the valve slide ( 6 ). 5. Valve arrangement according to one of the claims 1 to 3, characterized in that each valve slide side is assigned an electromagnet arrangement ( 8 , 10 ) via which the valve slide ( 6 ) can be acted upon in two directions. 6. Valve arrangement according to claim 5, characterized in that the electromagnet arrangement with pulling and pushing direction of action is a double stroke magnet ( 8 , 10 ). 7. Valve arrangement according to claim 5, characterized in that the electromagnet arrangement ( 8 , 10 ) is formed by two coaxially connected electromagnets, the armatures of which are connected to one another. 8. Valve arrangement according to one of the preceding Pa claims, characterized in that the electromagnets ( 8 , 10 ) are proportional magnets with displacement transducers. 9. Valve arrangement according to one of claims 2 to 8, characterized in that each spring ( 12 , 14 ) on the associated armature ( 16 to 19 ) is supported by a spring plate, which in turn is supported in the zero position of the armature on a housing shoulder. 10. Valve arrangement according to one of the preceding Pa claims, characterized in that the Ven slide valve ( 6 ) via centering springs ( 24 , 26 ) is biased into its zero position, which is supported on the one hand on the valve housing ( 2 ) and on the other hand on a spring plate ( 28 , 30 ) which can be brought into contact with a valve spool end face and which is pretensioned against the valve housing ( 2 ) in the zero position of the valve spool ( 6 ). 11. Valve arrangement according to claim 10, characterized in that the bias of the two springs ( 12 , 14 ) between 50 and 100 N, the bias of the centering spring about 1/10 thereof and the force to be applied by each magnet approximately corresponds to the spring force.