EP2461045A1 - Valve assembly - Google Patents

Abstract

The valve assembly (1) has a main valve (4) associated with an electrically actuated pilot valve (5), and a valve chamber (12). The valve chamber feeds controllable amount of print medium through the main valve element (13) to the main feed channel (28a) of a branch portion. The main feed channel is partially traversed on the downstream side of a fluid channel (28), while the branch opening (45) feeds the print medium into the main channel at the time of flanking of flow retaining wall (53).

Description

The invention relates to a valve arrangement, comprising at least one main valve and at least one main valve associated, electrically actuated pilot valve, wherein the main valve at least one arranged in a valve chamber, controlled by the pilot valve Fluidbeaufschlagung switchable between different switching positions main valve member, wherein in the valve chamber to a At least one leading to the at least one pilot valve and this supplying with the pressure medium used for the controlled fluid loading of the main valve member supplying pilot feed channel branches off laterally with a branch opening from the main feed channel controllable pressure medium serving main feed channel of the valve assembly ,

One from the EP 0 442 033 A1 known valve arrangement of this type has a means of two pilot valves electropneumatically pilot-controlled main valve, which is mounted on a penetrated by fluid channels connector body. The main valve is equipped with a switchable by the pilot valves valve member, which is housed axially movable in a valve chamber into which, among other things, opens a main feed channel. The pressure medium is introduced via the main feed channel, which is achieved by means of the main valve is controllable to actuate a connected consumer by means of fluid power. The pilot valves are electrically activatable and are capable of imparting to the main valve member a fluidic switching signal provided in a pilot feed channel. To avoid complex subsequent measures, the pilot feed channel is not supplied separately with pressure medium, but from the main feed channel. For this purpose, each pilot feed duct is branched off laterally from the main feed duct in a branch region formed in the connection body.

When operating the known valve arrangement, it has been noticed that the switching operations of the main valve member initiated by the pilot valves are prone to failure when the pressure of the pressure medium supplied to the main feed channel is not particularly high. This is attributed to the fact that when switching the main valve in the branch region, an ejector effect occurs, due to which a pressure drop occurs in the sideways outgoing feed control channel, so that the static pressure present here is no longer sufficient to build up a sufficiently high switching force for the main valve member. The problem of problems occurs in practice, especially when the valve assembly is operated at a working pressure, which is at the lower limit of the switching pressure required for switching the main valve member.

So far, one has resolved to solve the problem so that one in departure from the in the EP 0 442 033 A1 described connection principle has made a separate supply of the pressure medium used for pilot control. The pilot valves are then supplied externally with pressure medium. However, this requires additional connection means to the valve assembly and additional follow-up measures the installation of the valve assembly. Regardless of this additional expense, the external fluid supply of the pilot valves must also take into account the dependence between the working pressure and the pilot pressure which is usually present on the part of the user in order to ensure a safe switching operation.

The invention has for its object to provide measures that ensure a reliable switching of the main valve member in a valve assembly of the type mentioned even at low working pressures.

To achieve this object, it is provided in a valve arrangement of the type mentioned that in the branch region a main feed channel at least partially crossing while the branch opening of the at least one pilot feed channel flanking on the downstream side of the main feed channel flow dam wall is arranged for the fed into the main feed channel pressure medium.

It has been found that it is possible to greatly reduce the suction effect occurring with respect to the pilot feed duct by inserting a flow dam wall into the main feed duct in the region adjoining the branch opening in the downstream direction of the main feed duct. The ejector effect which has hitherto occurred when the pilot feed ducts are branched off from the main feed duct is greatly reduced by the selective generation of a stable static pressure in the region of the branch opening. The dynamic pressure fluctuations in this area are reduced to a minimum. Even with a low working pressure of the fed into the main feed channel pressure medium can thus ensure a safe switching of the main valve member by the diverted from the main feed channel pilot pressure. The pressure medium fed into the main feed duct is prevented by the flow stow wall from flowing past the branch opening of the pilot feed duct which opens laterally into the main feed duct at high speed. The flow damper wall accumulates the fluid flow locally, so that the dynamic pressure component is reduced in favor of the static pressure component and a sufficiently high switching pressure is provided on the pilot control side. Thus, since it is possible to branch the pilot pressure internally in the valve assembly from the main feed channel, the cost of manufacturing and installing the valve assembly can be kept to a low level. Advantageous developments of the invention will become apparent from the dependent claims.

It is advantageous if the flow blocking wall framed the branch opening along part of its circumference. In this case, it may in particular have an arcuate cross-section at least in some areas.

In one possible embodiment, the main feed channel is penetrated by the flow restriction wall in the transverse direction and in particular diametrically completely. The flow dam wall is expediently attached to two opposite wall sections of the channel wall of the main feed channel and preferably formed integrally with this channel wall. It will be understood that the flow restriction wall is to be designed in such a way that the pressure medium fed into the main feed channel still has the possibility of passing through the flow blocking wall and flowing to the valve chamber of the main valve. To realize this is expediently provided that one side or both sides laterally between the flow restriction wall and the channel wall of the main feed channel a Through opening sufficiently large cross section for the valve chamber to be supplied pressure medium is present. A construction in which the flow blocking wall only partially traverses the main feed channel and thus protrudes freely into the main feed channel is considered to be particularly advantageous. In this way, the flow cross section of the main feed channel is minimally narrowed by the flow restriction wall and the flow rate of the valve assembly is not affected relevant.

It is particularly expedient if the flow restriction wall extends maximally to the middle of the channel into the main flow channel. Conveniently, it even ends a little way in front of the middle of the channel of the main feed channel.

The flow blocking wall is in particular arranged such that, starting from a section of the channel wall of the main feed channel framing the branch opening, it extends into the main feed channel transversely to the longitudinal direction of the main feed channel.

If the direction of the flow stagnation wall in which it extends into the main feed channel from the region of the main feed channel adjacent the branch opening is referred to as the longitudinal direction of the flow stow wall, it is advantageous if the flow stow wall has a width such that it completely occupies or fills the cross-section of the main feed channel over its entire length. Consequently, the flow reaching the valve chamber can only flow past the free end face of the flow restriction wall. In contrast, in the region upstream of the flow restriction wall in the upstream direction of the main feed channel, there is a considerable increase Flow congestion and usually also creates turbulence, which means that there is a static pressure in the region of the branch opening, which is only slightly lower than the working pressure of the fed into the main feed channel pressure medium.

There is the advantageous possibility of still supporting the fluid supply of the pilot feed duct by providing the flow stow wall with at least one suitably shaped flow guide surface at its underside oriented in the upstream direction of the main feed duct. This flow guide expediently has an inclined course relative to the axial direction of the branch opening. Particularly advantageous is a pertinent design of at least one flow guide, that selbige starting from one of the branch opening axially opposite free end face of the Strömungsstauwand has a skew, which is oriented in the direction of the branch opening and - superimposed on it - in the downstream direction of the main feed channel.

In particular, when the Strömungsstauwand projects freely ending in the main feed channel, it is advantageous if it has a central, arcuate wall portion, and two adjacent each at a longitudinal side of this arcuate wall section subsequent, wing-like projecting wall sections. In particular, the wing-like wall sections may have at their oriented in the upstream direction of the main feed channel bottom via an inclined flow guide, which deflect the approaching in the main feed channel pressure medium at least partially in the direction of the transverse and in particular at right angles to the longitudinal axis of the main feed channel oriented branch opening.

The branch region for the pilot control feed channel can be located directly in the main valve or in a valve housing of the main valve in a corresponding embodiment of the valve assembly. This is especially the case when the main valve is operated as a single valve.

The valve arrangement may be designed such that it has a connection body which acts as a support for the main valve and to which the main valve is detachably fastened or fastened. Again, the branch area may well be inside the main valve. Alternatively, however, there is also the advantageous possibility of providing the branch region in the connection body. In this case, the pilot feed passage branches in the connector body from the main feed passage, and both feed passages suitably lead to a mounting surface of the connector body to which the main valve is mountable so as to communicate with both the main feed passage and the pilot feed passage.

Regardless of its specific embodiment, it is expedient if the flow restriction wall is formed integrally with the channel wall delimiting the main feed channel. This allows a particularly simple production.

The main valve is expediently combined with at least one pilot valve to form a valve unit. The pilot valve is expediently mounted detachably on the main valve. If the valve arrangement contains a connection body, the valve unit can be detachably mounted as a structural unit on the connection body or be.

Figur 1

eine bevorzugte erste Ausführungsform der erfindungsgemäßen Ventilanordnung in einer perspektivischen Ansicht,

Figur 2

eine Draufsicht auf einen Anschlusskörper der Ventilanordnung aus Figur 1 im abgenommenen Zustand des Hauptventils und des Vorsteuerventils und in einer Blickrichtung gemäß Pfeil II aus Figur 1,

Figur 3

einen Längsschnitt durch die Ventilanordnung aus Figuren 1 und 2 gemäß Schnittlinie III-III,

Figur 4

den in Figur 3 umrahmten Ausschnitt IV, der den Abzweigbereich illustriert, in einer vergrößerten Darstellung,

Figur 5

einen Querschnitt durch die Ventilanordnung gemäß Schnittlinie V-V aus Figuren 2 und 3 ohne Abbildung des Hauptventils,

Figur 6

eine Einzeldarstellung des Anschlusskörpers der aus Figuren 1 bis 5 hervorgehenden Ventilanordnung im Längsschnitt gemäß Schnittlinie V-V,

Figur 7

in einem Längsschnitt gemäß Schnittlinie VII-VII aus Figur 8 den Anschlusskörper einer weiteren vorteilhaften Ausführungsform der erfindungsgemäßen Ventilanordnung,

Figur 8

eine Draufsicht auf den Anschlusskörper der Figur 7 mit Blickrichtung gemäß Pfeil VIII aus Figur 7,

Figur 9

den in Figur 7 strichpunktiert umrahmten Ausschnitt, der den Abzweigbereich illustriert, in einer vergrößerten Darstellung,

Figur 10

einen Querschnitt durch den Anschlusskörper der Figuren 7 und 8 gemäß Schnittlinie X-X darin, und

Figur 11

einen Längenabschnitt des in Figuren 7 bis 10 abgebildeten Anschlusskörpers, wobei die Schnittebene derjenigen der Figur 10 entspricht.

The invention will be explained in more detail with reference to the accompanying drawings. In this show:

FIG. 1

a preferred first embodiment of the valve assembly according to the invention in a perspective view,

FIG. 2

a plan view of a connector body of the valve assembly FIG. 1 in the removed state of the main valve and the pilot valve and in a viewing direction according to arrow II FIG. 1 .

FIG. 3

a longitudinal section through the valve assembly Figures 1 and 2 according to section line III-III,

FIG. 4

the in FIG. 3 framed section IV, which illustrates the branch area, in an enlarged view,

FIG. 5

a cross section through the valve assembly according to section line VV Figures 2 and 3 without illustration of the main valve,

FIG. 6

an individual representation of the connection body of FIGS. 1 to 5 resulting valve assembly in longitudinal section along section line VV,

FIG. 7

in a longitudinal section along section line VII-VII FIG. 8 the connection body of a further advantageous embodiment of the valve arrangement according to the invention,

FIG. 8

a plan view of the connection body of FIG. 7 looking in the direction of arrow VIII FIG. 7 .

FIG. 9

the in FIG. 7 dash-dotted framed section illustrating the branch area, in an enlarged view,

FIG. 10

a cross section through the connecting body of FIGS. 7 and 8 according to section line XX therein, and

FIG. 11

a longitudinal section of in FIGS. 7 to 10 illustrated connecting body, wherein the sectional plane of the FIG. 10 equivalent.

In the embodiment of the FIGS. 7 to 11 corresponds to the structure of the main valve and pilot valve, not shown, that of the embodiment of FIGS. 1 to 6 , Explanations referring to the main valve and pilot valve according to FIGS. 1 to 6 Accordingly, apply accordingly also for the embodiment of FIGS. 7 to 11 ,

The two exemplary illustrated and in their entirety each provided with reference numeral 1 valve assemblies each contain an example block-shaped or plate-shaped connector body 2 and a pilot-controlled valve unit 3. The valve unit 3 is composed of a main valve 4 and attached to the main valve 4 pilot valve 5 together. A modified construction, not shown, of the valve unit 3 has two pilot valves 5.

The union of the main valve 4 and the at least one pilot valve 5 to a valve unit 3 facilitates handling. However, the at least one pilot valve 5 could also be formed and arranged separately from the main valve 4 (not shown).

The connecting body 2 forms a support for the valve unit 3. It has an assembly surface 6, which is designed to be equipped in a particularly releasable manner with the valve unit 3. The FIGS. 1 and 3 Fastening means 7, in the embodiment in the form of hook means 7a and screw fasteners 7b, allow releasable fixing of the valve unit 3 in the attached to the mounting surface 6 state.

In one embodiment, not shown, the valve assembly 1 contains no connector body 2. Here, the valve unit 3 is otherwise mounted at any location. The design with connector body 2 has the advantage that a plurality of valve assemblies 1 can be very easily combined to form an assembly or valve batteries, in which the connector body 2 are in fluid communication with each other to allow a central supply and discharge of pressure medium.

The main valve 4 has a valve housing 8, in which a valve chamber 12 is formed, in which a main valve member 13 is received. The main valve member 13 is in the valve chamber 12 under execution of a switching movement 14 in particular linearly movable. In this way, the main valve member 13 can be switched between a plurality of switching positions.

The main valve member 13 of the embodiment can take two switching positions. Shown is a first switching position, which represents a basic position assumed in the unactuated state in the embodiment and which is due to the fact that the main valve member 13 is constantly from a on the other hand, on the valve housing 8 supported return spring means 15 is acted upon.

In the second switching position, the main valve member 13 can switch over that a motion coupled to him and preferably firmly connected to him drive surface 16 is acted upon by a fluidic pressure medium. The drive surface 16 is expediently located on an end face of the main valve member 13.

The fluid loading of the drive surface 16 is controlled by the pilot valve 5. The same has in the embodiment, the functionality of a 3/2-way valve and is able to connect by appropriate positioning of a pilot valve member 17 a pilot control working channel 18 selectively with a pilot feed 22 or a pilot discharge passage 23 fluidly.

The pilot working channel 18 extends between a pilot chamber 24 of the pilot valve 5 and a drive chamber 25 of the main valve 4, wherein the drive chamber 25 is limited, among other things of the drive surface 16 as a movable wall.

Through the pilot control feed 22 through the pilot valve 5 is supplied with pressure medium, which will be referred to as a pilot control medium for better distinction below. When the pilot valve member 17 assumes a closed position, which is normally in the unactuated state of the pilot valve 5, it separates the Vorsteuerspeisekanal 22 from the pilot chamber 24 by abutment against a valve seat 26 and connects the same simultaneously with the leading to the atmosphere Vorsteuer-Abfuhrkanal 23, so that through them a pressure relief of the drive chamber 25th is possible. Accordingly, the main valve member 13 assumes the already mentioned first switching position.

To spend the main valve member 13 in the second switching position, the electrically actuated and in particular designed as a solenoid valve pilot valve 5 is electrically activated. For this purpose, an actuating voltage is applied to contact means 27 of the pilot valve 5. As a result, the pilot valve member 17 moves to an open position in which it disconnects the pilot discharge passage 23 from the pilot chamber 24 and at the same time, due to its lifting from the valve seat 26, the pilot chamber 24 connected to the drive chamber 25 via the pilot working passage 18 connects to the pilot feed 22.

Now pilot medium can flow into the drive chamber 25 and build pressure therein which acts on the drive surface 16 and causes a switching force which is greater than the restoring force of the return spring means 15. As a result, the main valve member 13 shifts from the first switching position to the second switching position.

To switch back the main valve member 13 in the first switching position, only the pilot valve 5 is to be deactivated again, so that the pressure prevailing in the drive chamber 25 pressure on the pilot discharge channel 23 can degrade.

In the valve chamber 12 open at axially spaced locations, a plurality of fluid channels 28, which pass through the valve housing 8 of the main valve 4 and of which at least one of the connecting body 2 passes through in the case of existing connector body. It is therefore possible that at least one fluid channel 28 extends only in the valve housing 8 of the main valve 4 and that at least one fluid channel 28 has successive lengths, one of which is formed in the connection body 2 and the subsequent in the valve housing 8 of the main valve 4.

Of the existing fluid channels 28 forms one for better distinction hereinafter referred to as the main feed channel 28a feed channel. It is connected during operation of the valve assembly 1 to a pressure source P, which is in particular a compressed gas source and preferably a compressed air source. The pressure source P supplies a fluid pressure medium under a certain working pressure and thus supplies the main valve 4.

At least one further fluid channel 28 acts as a working channel 28b. To him a consumer to be driven can be connected, for example, actuated by fluid force drive device.

Another fluid channel 28 represents a discharge channel 28c, which is connected during operation of the valve assembly 1 with a pressure sink. When the valve assembly 1, as is the case in the embodiment, is operated with compressed air as the pressure medium, the relief channel 28c is a venting channel connected to the atmosphere.

With the fluid channel equipment described so far, the main valve 4 can fulfill the functionality of a 3/2-way valve.

By way of example, the main valve 4 has a higher functionality. It is designed here as a 5/2-way valve and has two further fluid channels 28, one of which forms another working channel 28 e and another another discharge channel 28 f.

To connect the main feed channel 28a to the pressure source P and to connect a respective working channel 28b, 28e with the consumer to be controlled, the valve assembly 1 is expediently equipped with connection units 32, on which away from the valve assembly 1 leading fluid lines 33, for example, compressed air hoses, under seal solvable connect.

The discharge channels 28c, 28f can also be provided with such connection units 32 if required. However, if, as in the embodiment, the pressure relief can take place directly to the atmosphere, it is more expedient to equip the discharge channels 28c, 28f only with mufflers 34.

The functionality of the main valve 4 is in the embodiment now that in the first switching position of the working channel 28b is connected to the main feed channel 28a and at the same time separated from the discharge channel 28c. In the second switching position of the working channel 28b communicates with the discharge channel 28c and is separated from the main feed channel 28a. On this functionality, the main valve 4 would be limited to a 3/2-way valve.

In the illustrated embodiment as a 5/2-way valve is added that in the first switching position additionally the further working channel 28e is connected to the other discharge channel 28f and separated from the main feed channel 28a. In addition, in the second switching position, there is a connection of the further working channel 28e with the main feed channel 28a, while at the same time it is separated from the further discharge channel 28f.

In this way, the two working channels 28b, 28e can be alternately acted upon or relieved of pressure by pressurized medium under the working pressure.

In the case of the valve arrangement 1 of the exemplary embodiment, the two working channels 28b, 28e extend exclusively in the wall of the valve housing 8. The main feed channel 28a, however, in the exemplary embodiment consists of a longitudinal section designated as a valve channel 34, passing through the wall of the valve housing 8 and adjoining it Terminal body channel 35 designated and the terminal body 2 passing through the longitudinal section together. The same also applies to the two relief channels 28c, 28f, in which the length extending in the valve housing 8 for better distinction with reference numeral 34a and extending in the connector body 2 longitudinal sections are designated by reference numeral 35a.

The length sections 35, 35a of the main feed channel 28a and the discharge channels 28c, 28f extending in the connection body 2 open at a distance from each other at the component surface 6. The associated, extending in the valve housing 8 longitudinal portions 34, 34a open to that base 36 of the valve housing 8 out, with the main valve 4 rests in the assembled state of the mounting surface 6, wherein the mouths are distributed so that they mounted in the connection body 2 State of the main valve 4 with the extending in the connection body 2 lengths 35, 35 a of the fluid channels 28 are aligned correctly.

In a non-illustrated embodiment of the main feed channel 28a as well as the other fluid channels 28 expediently runs in its entirety in the wall of the valve housing. 8

The main feed channel 28a extends between a channel inlet 37 and a channel outlet 38. The channel inlet 37 is provided to be connected to the pressure source P, in particular by means of a connection unit 32 and a fluid line 33, wherein the pressure medium to be controlled by the main valve 4 is located on the Channel input 37 is fed into the main feed channel 28a. The channel exit 38 of the main feed channel 28a opens into the valve chamber 12 in order to feed the pressure medium originating from the pressure source P into the valve chamber 12. In the interior of the main feed channel 28a, the pressure medium originating from the pressure source P flows from the channel inlet 37 in the direction of the channel outlet 38. Thus, the main feed channel 28a has a downstream direction 42 directed towards the channel outlet 38 and an oppositely oriented upstream direction 43. These two directions of extension are in FIG the drawing indicated by arrows.

The pilot feed channel 22 is fed from the main feed channel 28a with the pressure medium to be supplied to the pilot valve 5 as a pilot control medium. For this purpose, the pilot feed channel 22 branches off laterally from the main feed channel 28a in a branch region 44. The pilot feed duct 22 has at its the pilot valve 5 and its pilot chamber 24 opposite end via a designated as branch opening 45 channel opening, with which it opens laterally, ie at the main feed channel 28a defining peripheral channel wall 46, in the main feed channel 28a.

The branch opening 45 is aligned in particular at right angles to the channel longitudinal direction of the main feed channel 28a in the branch region 44.

A rectangular opening opening 47 of the branch opening 45, which is perpendicular to the opening cross section of the branch opening 45, extends expediently at right angles to the channel longitudinal axis 48 of the main feed channel 28a in the branch region 44.

If the main feed channel 28a, as in the exemplary embodiment, at least in the branch region 44 has a rectangular channel cross-section - preferably with rounded corner regions - the branch opening 45 is expediently located on one of the four mutually perpendicular wall sections of the channel wall 46, so that the opening cross-section Branch opening 45 preferably extends in a plane.

The branching region 44, in which the pilot feed channel 22 opens into the main feed channel 28a with its branch opening 45, lies upstream of the valve chamber 12. On its way from the channel inlet 37 to the channel outlet 38, the pressure medium consequently flows past the branch opening 45. A certain proportion of the pressure medium branches off into the pilot control feed channel 22 in order to flow as a pilot control medium to the pilot control valve 5. The branch flow is illustrated by an arrow at 52 in the drawing.

In the interior of the main feed channel 28a, located downstream of the branch opening 45 in the downstream direction 42, there is a flow obstacle designated flow stow wall 53, which prevents the pressure medium fed at the channel inlet 37 from flowing unaffected and at high speed past the branch opening 45. The flow blocking wall 53 extends in the interior of the main feed channel 28a transversely to its channel longitudinal axis 48 and counteracts the pressure medium flowing in the downstream direction 42, a flow resistance. In this way, 45 usually occurring dynamic pressure fluctuations are selectively converted into a stable static pressure in the region of the branch opening. This has to

Consequence that the working pressure applied to the channel inlet 37 is derived unrestricted or with at least only a slight pressure drop as a pilot pressure for the pilot valve 5. In this way, high reliability for a reliable pilot function is given even at a low working pressure.

The problem of a pressure drop occurs in the branch region 52 when switching the main valve member 13. At the moment when a previously pressureless working channel 28d or 28e is connected to the main feed channel 28a, a high flow rate is established in the main feed channel 28a, associated with a high flow rate also in the branch region 44. The flow stagnation wall 43 at least partially traversing the main feed channel but hinders now the fluid flow in the branch opening 45 immediately upstream region of the main feed channel 28a, so that the dynamic pressure component is reduced in favor of the static pressure component and the pilot medium remains at a pressure level sufficient to act by applying the drive surface 16 a fast and complete Switch over the main valve member 13 from the first switching position to the second switching position cause.

The flow stagnation wall 53 extends in both embodiments, starting from a portion of the channel wall 46 framing the branch opening 45 in the transverse direction of the main feed channel 28a into the main feed channel 28a. The direction of the entry into the main feed channel 28a of the flow blocking wall 53 is referred to below as the longitudinal direction of the flow blocking wall 53, it extends in the same direction as the opening longitudinal axis 47th

The flow dam walls 53 of the two exemplary embodiments differ, above all, in their length in relation to the diameter of the main feed channel 28a. While the flow dam wall 53 in the embodiment of FIGS. 7 to 11 the main feed channel 28 a completely traverses, that extends between two facing and opposite portions of the channel wall 46, it traverses in the case of the embodiment of FIGS. 1 to 6 the main feed channel 28a only partially and protrudes, with a front facing away from the branch opening 45 front end surface 54, freely ending in the main feed channel 28a into it.

However, in both cases it is in turn common that the branch opening 45 is framed by the flow blocking wall 53 along a part of its circumference. The flow blocking wall 53 in particular does not have a straight cross-section transversely to its longitudinal extension, but at least in some areas has an arcuate section 55 with a curved cross-section, the concave side of which faces the upstream direction 43. In the region of the curved section 55, the flow blocking wall 53 therefore expediently has a groove-shaped structure, with the longitudinal groove opening facing the pressure medium flowing in from the channel inlet 37.

The Strömungsstauwand 53 may be formed arcuate in its entire cross section. This is exemplified in the embodiment of FIGS. 7 to 11 the case. The flow dam wall 53 is formed there by the arc section 55, which is expediently circular arc-shaped.

The Strömungsstauwand 53 may also be profiled so that the arcuate portion 55 occupies only a portion of the cross-sectional profile. To show the FIGS. 1 to 6 an advantageous embodiment, wherein placed on the cross-section centered Arc section 55 on both longitudinal sides in each case a wing-like wegragender, hereinafter referred to as wing section 56 connects wall section which extends transversely and in particular at right angles to the opening longitudinal axis 47 to the outside.

The axial length of the wing sections 56 is chosen in particular such that they are flush with the front end face 54 of the flow blocking wall 53, and therefore define the front end face 54 together with the end face of the arc section 55.

The wall section of the channel wall 46 on which the branch opening 45 is located and from which the flow blocking wall 43 extends into the main feed channel 28a is referred to below as the base wall section 46a. The wall section of the main feed channel 28a opposite the base wall section 46a, transverse to the longitudinal direction of the main feed channel 28a, will hereinafter be referred to as the opposite wall section 46b. The two wall sections of the main feed channel 28a extending between the base wall section 46a and the opposite wall section 46b along both sides of the flow blocking wall 43 will be referred to below as lateral wall sections 46c, 46d.

In the embodiment of FIGS. 7 to 11 The flow restriction wall 43 extends in its longitudinal direction from the base wall portion 46a to the opposite wall portion 46b, uninterrupted. The flow blocking wall 53 is fixed in particular to both of these wall sections 46a, 46b. The fixation is in particular realized in that the flow dam wall 53 is in each case integrally connected to the channel wall 46 of the main feed channel 28a. If the body containing the main feed channel 28a-for example, the connection body 2 by way of example-consists of a plastic material, the flow blocking wall 53 can be formed directly at low cost during its injection molding production.

In the embodiment of FIGS. 1 to 6 ends the Strömungsstauwand 53 at a distance in front of the opposite wall portion 46b. Thus, there is a gap between the opposite wall section 46b and the front end face 54 of the flow blocking wall 53 facing this wall section 46b.

Also, for the main flow passage 28a only partially traversing Strömungsstauwand 53 is that it is preferably integrally attached to the channel wall 46 so that it protrudes quasi only in the manner of a wall projection in the main feed channel 28a.

In both embodiments, it is advantageous to arrange the flow blocking wall 53 so that it extends at least substantially diametrically in the main feed channel 28a. In the embodiment of FIGS. 7 to 11 the main feed channel 28a is penetrated diametrically by the flow blocking wall 53.

In the design of the flow dam wall 53, the aim should be to minimize the impact on the flow medium provided by the main feed channel 28a for the pressure medium as little as possible. In that regard, the free flow into the main feed channel 28a projecting flow blocking wall 53 has the advantage that between its front end surface 54 and the opposite wall portion 46b, a relatively large cross section for the valve chamber 12 to flow Print medium can be provided. The axial length of the flow blocking wall 53 may be relatively short, so that it extends in particular to at most the channel center of the main feed channel 28a. However, the flow stow wall 53 expediently ends with its front end face 54 even before reaching the channel longitudinal axis 48 in the branch region 44.

In order to achieve an optimal accumulation effect for the incoming pressure medium despite a relatively short flow stagnation wall 53, it is expedient to design the flow stagnation wall 53 such that it occupies or fills the cross section of the main feed channel 28a over its entire length measured in the axial direction of the opening longitudinal axis 47 , The pressure medium flowing in from the channel inlet 37 is thus prevented from flowing laterally past the flow blocking wall 53. By way of example, this is realized in that the wing sections 56 extend laterally as far as the channel wall 46. In the specific case of the exemplary embodiment, the two wing sections 56 extend in each case to the adjacent lateral wall section 46c, 46d with which they are expediently connected in one piece.

In the embodiment of FIGS. 7 to 11 This results in a relatively large storage area for the oncoming pressure medium by the relatively large length of the main feed channel 28a completely passing through the flow dam wall 53. This offers the possibility of relatively small in the cross section of the main feed channel 28a width of the flow blocking wall 53 form relatively small, so that between each longitudinal side of the Flow dam wall 53 and the opposite side wall portion 46c, 46d, a particular gap-shaped passage opening 57 remains, which flows through the medium flowing from the channel 37 to the channel 38 output medium can be. The passage openings 57 preferably extend over the entire axial length of the flow blocking wall 53.

In one embodiment, not shown, a passage opening 57 is located only on one of the two longitudinal sides of the flow blocking wall 53. In such a case, however, it is advantageous if the branch opening 45 does not open diametrically but eccentrically laterally into the main feed channel 28a, for example in the immediate vicinity one of the lateral wall portions 46c or 46d. Thus, the flow blocking wall 53 can be provided with a relatively small width transversely to its longitudinal axis, with the result that a relatively wide passage opening 57 for the pressure medium can be provided on the other longitudinal side.

The flow stagnation wall 53 preferably has, at its lower side oriented in the flow direction 43, at least one flow guide surface 58 which at least partially imposes a change in direction, in particular in the direction of the branch opening 45, to the pressure medium flowing in the downstream direction 42.

The embodiment of FIGS. 1 to 6 is equipped with two such flow guide 58. One of each is located at the bottom of each wing section 56 FIG. 4 It can be seen that these flow guide surfaces 58 are inclined relative to the opening longitudinal axis 47.

The flow guide surfaces 58 may in particular run obliquely starting from the free, front end face 54, that they extend in the direction of the branch opening 45 and at the same time, superimposed, in the current direction 42.

The flow guide surface 58 may be a flat surface or a curved surface.

Each flow guide 58 can also, as in particular in FIG. 5 is apparent and in FIG. 10 is indicated by dash-dotted lines as an optional variant, have such a skew, that they - viewed in cross-section perpendicular to the opening longitudinal axis 47 - with respect to the channel longitudinal axis 48 is inclined. The oblique position is chosen in particular such that the flow guide surface 58 extends obliquely inwards in the direction of the center of the main feed channel 28a and at the same time in the current direction 42.

The inclinations of the flow guide surface 58 described can readily be realized superposed.

In all embodiments, the selected geometry of the Strömungsstauwand 53 ensures that almost the full height of the working pressure is available as a pilot pressure for the actuation of the main valve member 13, even if during a switching operation of the main valve member 13 in the branch region 44 high flow velocities occur. By means of a very cost-effective measure can be ensured in this way a high reliability for the main valve 4 and the entire valve unit 3.

When the branch portion 44, as in the embodiments, is formed in a separate connector body 2 supporting the main valve 4, the flow dam wall 53 is thus realized in the connector body 2 is also such main valves 4 benefit from the improved reliability, which have no measures for the internal tap of the pilot medium. It should be noted, however, that the inventive measures readily in a valve housing 8 of the main valve member 13 extending main feed channel 28a or longitudinal section of the main feed channel 28a can be realized when the branch region 44 is located in this valve housing 8.

In particular, if a plurality of pilot valves 5 are to be supplied with pilot medium from one and the same main feed channel 28a, the main feed channel 28a can have a plurality of branch regions 44 which are spaced apart in their longitudinal direction, at each of which a pilot feed channel 22 opens and which are each assigned via one of the branch apertures 45 located there Flow dam wall 53 have.

It is also possible for a plurality of branch openings 45 of one or more pilot feed ducts 22, which are arranged offset to one another in the circumferential direction of the main feed channel 28a, to open into the same branching region 44a. Here, each branch opening 45 can then be assigned its own flow dam wall 53, as is the possibility of assigning one and the same flow dam wall 53 to a plurality of branch openings 45. For example, in the embodiment of the FIGS. 7 to 11 a branch opening 45 may be provided not only on the base wall portion 46a but also on the opposite wall portion 46b, particularly such that the branch openings 45 are opposite to the longitudinal direction of the main feed channel 28a. At both branch openings 45, one and the same, the main feed channel 28a then passes completely through flow stowage wall 53 in the downstream direction 42.

Claims (15)

Valve arrangement, with at least one main valve (4) and at least one electrically actuated pilot valve (5) associated with the main valve (4), wherein the main valve (4) controls at least one valve chamber (12) controlled by the pilot valve (5) Fluid switching between different switching positions switchable main valve member (13), wherein in the valve chamber (12) for supplying a controllable by the main valve member (13) pressure medium serving main feed channel (28a) of the valve assembly (1) opens and wherein of the main feed channel (28a) in a branching region (44) located upstream of the valve chamber (12) branches off laterally with a branch opening (45) leading to the at least one pilot valve (5) and supplying it with the pressure medium used for controlled fluid admission of the main valve member (13) , characterized in that in the branching ch (44) a the main feed channel (28a) at least partially crossing while the branch opening (45) of the at least one pilot feed channel (22) on the downstream side of the main feed channel (28a) flanking Strömungsstauwand (53) for the fed into the main feed channel (28a) pressure medium is arranged. Valve arrangement according to claim 1, characterized in that the flow blocking wall (53) surrounds the branch opening (45) along a part of its circumference. Valve arrangement according to claim 2, characterized in that the Strömungsstauwand (53) at least partially has an arcuate cross-section. Valve arrangement according to one of claims 1 to 3, characterized in that the flow stagnation wall (53) passes completely through the main feed channel (28a), leaving at least one passage opening (57) permitting a passage of the pressure medium, expediently being arranged on opposite wall sections (28). 46a, 46b) of the channel wall (46) of the main feed channel (28a), in particular in one piece, is fixed. Valve arrangement according to claim 4, characterized in that the flow blocking wall (53) passes through the main feed channel (28a) diametrically. Valve arrangement according to claim 4 or 5, characterized in that laterally, in particular on both sides, between the flow blocking wall (53) and the channel wall (46) of the main feed channel (28a) there is a passage opening (57) for the pressure chamber to be supplied to the valve chamber (12). Valve arrangement according to one of claims 1 to 3, characterized in that the flow blocking wall (53) only partially passes through the main feed channel (28a) and projects freely into the main feed channel (28a). Valve arrangement according to claim 7, characterized in that the flow dam wall (53) starting from one of the Branching opening (45) framing portion of the channel wall (46) of the main feed channel (28 a) transversely to the longitudinal direction of the main feed channel (28 a) into the main feed channel (28 a) extends. Valve arrangement according to claim 7 or 8, characterized in that the Strömungsstauwand (53) protruding from the edge region of the branch opening (45) in a longitudinal direction in the main feed channel (28a), wherein the cross section of the main feed channel (28a) expediently over its entire length busy. Valve arrangement according to one of claims 1 to 9, characterized in that the Strömungsstauwand (53) at its in the Stromaufrichtung (43) of the main feed channel (28a) oriented underside at least one flow guide surface (58), which is expediently inclined with respect to the longitudinal direction of the main feed channel , wherein in particular an inclination with respect to an opening cross-section of the branch opening (45) perpendicular opening longitudinal axis (47) is present. Valve arrangement according to one of claims 1 to 10, characterized in that the Strömungsstauwand (53) at its in the upstream direction (43) of the main feed channel (28a) oriented bottom at least one flow guide surface (58) which, starting from one of the branch opening (45) remote free end surface (54) of the Strömungsstauwand (53) has such an oblique course that it extends in the direction of the branch opening (45) and at the same time in the Stromabrichtung (42) of the main feed channel (28a). Valve arrangement according to one of claims 1 to 11, characterized in that the Strömungsstauwand (53) via a central, arcuate wall portion (55) and two each on a longitudinal side laterally to this arcuate wall portion (55) adjoining wing-like projecting wall portions (56) has, wherein the wing-like wall portions (56) expediently at its in the upstream direction (43) of the main feed channel (28a) oriented side each have an inclined flow guide surface (58). Valve arrangement according to one of claims 1 to 12, characterized in that it has a connection body (2) to which the main valve (4) is detachably fastened or fastened, wherein the main feed channel (28a) partly in the connection body (2) and partly in a valve housing (12) containing valve housing (8) of the main valve (4) and wherein the branch region (44) for the pilot feed channel (22) expediently in the connection body (2) extending longitudinal portion of the main feed channel (28a) is arranged. Valve arrangement according to one of claims 1 to 13, characterized in that the flow blocking wall (53) is formed integrally with the main feed channel (28a) defining the channel wall (46). Valve arrangement according to one of claims 1 to 14, characterized in that the main valve (4) and the at least one pilot valve (5) to a valve unit (3) are combined, wherein the branch region (44) in the interior of the main valve (4) or in a connection body (2) belonging to the valve arrangement (1), to which the valve unit (3) is detachably fastened or fastened.

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