DE10133990A1 - way valve - Google Patents

Abstract

The invention relates to a directional-control valve (1) comprising a connection (A) on the front face thereof and at least one radial connection (B). The front faces of the valve body (16) (valve sleeve or seat body) of the directional-control valve are impinged by approximately the same pressure, so that the actuating forces for displacing the valve body are minimal. According to the invention, the pressure to be subjected on a rearward front face (18) of the valve body is tapped at an axial distance from the valve body.

Description

The invention relates to a directional valve with an in a valve body guided through which a front connection connectable with a radial connection is.

Constantly adjustable directional valves are, for example used as a proportional adjustable throttle. The Directional control valve can flow through in two directions, i. H. once from the front connection to the radial connection and - in the opposite direction - from the radial connection to the front end Enough. The valve body can, for example, as cup-shaped valve slide be carried out in the Sheath radial openings are formed over which the Radial connection is open or closed. The actuation the valve is preferably done by means of a proportional adjustable electromagnet, via the plunger of the Valve body displaceable against the force of a compression spring is. In order to minimize the positioning forces, the pressure acting on the valve body via a connection bore into a rear pressure chamber, so that the Valve body is substantially pressure balanced.

In Fig. 11, to which reference is already made, the volume flow characteristic of such a 2/2-way valve is shown, wherein the stroke performed by the valve body above the relative input voltage of the electromagnet, ie above the input voltage related to the maximum voltage, is shown is. The different characteristic curves characterize the volume characteristics for different pressure differences Δp, the flattest characteristic curve representing a small pressure difference, while the characteristic curves become steeper with increasing pressure difference Δp. Referring to FIG. 11, the right, shallow curve progression corresponds approximately to a stable, ideal curve, as it is in general at a flow from the end-face connection to the radial port or - setting at low differential pressure - at a flow in the reverse direction. At higher pressure differences and volume flows (left characteristic curve in FIG. 11), the valve body may suddenly open. This abrupt tearing is characterized by the step in the left characteristic curve according to FIG. 11, according to which the stroke increases abruptly with a constant input voltage. Furthermore, Fig. 11 can be seen that there may be discontinuities in a flow from the radial connection to the stirnseiti gene connection at high volume flows, which are characterized by the fluctuations in the characteristic curve.

The above-mentioned discontinuities, ie the sudden tearing open of the valve body and the fluctuations in the end region of the stroke result from the flow forces acting on the valve body at high volume flows, which act on the valve piston in such a way that the actual throttle cross section does not correspond to the value at ideal conditions is currently determined by the input voltage. It is particularly disadvantageous that the characteristic curves for valves with the volume flow characteristic shown in FIG. 10 are different for the two flow directions, ie the flow from the front end connection to the radial connection and in the opposite direction, so that the control of consumers is not in the predetermined direction Way can be done.

In contrast, the invention is based on the object to create a directional valve in which in both flows directions occurring at high pressure differences Discontinuities are minimized.  

This task is accomplished by a directional valve with the characteristics len of claim 1 solved.

According to the back of the valve body not by effective pressure - as described at the beginning NEN solution - tapped directly on the valve body, but in the The area of the front connection, d. H. in through flow direction from the radial connection to the front Seen connection, downstream of the valve body. By this measure allows the influence of flow forces minimize on the valve body so that an erratic Tearing open the valve body or the occurrence of irregularities activities in the final stroke area eliminated or at least strongly can be reduced.

The directional valve can be used as a slide valve or as a seat Valve opened and closed when de-energized his. It can also be used as a switching valve or Train a continuously adjustable valve.

There are two ways of tapping the pressure several alternative solutions. In a ß solution is axial bore in the valve body det, the one hand in an inner end face of the valve body, and on the other hand in a rear, the pressure space-limiting end face of the valve body opens. In this axial bore is inserted into a tube that is out of the valve body towards the front Connection - or possibly beyond - extends.

In a second, alternative solution, the verb is Dung bore formed as a housing channel, the one hand in the area of the front connection and on the other hand opens into the pressure chamber. This solution is much more robust than the variant described above, in which the connection Break off the protruding tubes in the case of heavy loads  Chen or vibrate, so that a lot of effort to Attachment of the tube is required.

A difficulty in forming the housing channel consists in the fact that this must be placed so that it Radial connection does not cut, so that in particular the formation of the radial connection through radial bores tern a comparatively complex and exact ducting is required. The effort to train the housing nals can be reduced if this hole the radial bore or radial bores of the radial connection cuts and then through a preferably from the forehead inserted sealing tube is sealed.

The housing channel is preferably an angled hole executed, with an axially extending portion from frontal connection and an obliquely attached to it Leg is drilled as an oblique bore from the pressure chamber. Possible discontinuities at high pressure Differences can be seen particularly in the case of directional valves that are biased into an open position, further tighten gladly, if a second, parallel to one housing channel Connecting channel penetrating the valve body is provided over which the end acting on the valve body Pressure is tapped as control pressure.

The connecting channel passing through the valve body is preferably carried out with an axial section which merges into radial sections that in the rear Pressure chamber open.

In a variant of this solution, the valve is in it body-penetrating connecting channel between the front Ren face of the valve body and the radial sections at least one transverse bore is provided over which a wide rer control oil cross-section is controllable via the pressure  medium can get into the rear pressure chamber. This Control oil cross-section is according to a predetermined Axialver slide of the valve body open.

In a particularly easy to manufacture version for example, the radial connection of the directional valve opens directly, d. H. without a circumferential groove in the valve body Valve bore. Surprisingly, it turned out that the discontinuities with large pressure differences due to this direct junction of the radial connection Have the bore star reduced further.

The volume flow characteristic of the directional valve leaves improve further if the valve body has a housing fixed inner piston is assigned to the interior of the Valve body is arranged. One connected to the pressure room whose damping space is in this variant by End face of the inner bulb on the one hand and the inner forehead area of the valve body on the other hand limited. The appearing tendency flow forces are in the inside of the piston Housing initiated so that no interaction with the Valve body. The volume characteristic of a such directional valve is compared to the above Solutions significantly improved again. Fluctuations of the Pressure can be compensated for by the damping space is connected to the pressure chamber via a throttle bore.

The bearing of the inner piston is particularly simple, if this through a through the jacket of the valve body setting dowel pin is stored in the valve housing.

The valve body of the directional valve is preferably as Valve slide executed by a proportional magnet is adjustable.

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

Preferred embodiments of the Invention explained with reference to schematic drawings. Show it:

Fig. 1 shows a longitudinal section through a first embodiment of an inventive exporting approximately 2/2-way valve;

FIG. 2 shows a variant of the directional control valve from FIG. 1;

Fig. 3 shows another embodiment of a Wegeven valve, in which the pressure to compensate for the flow forces te is tapped via a tube;

Fig. 4, 5 sections through a further embodiment example of a directional valve with inner piston;

Fig. 6 characteristics of a 2/2-way valve according to the invention according to Figures 4, 5.

Fig. 7 is a sectional view of a game Ausführungsbei a directional control valve, which is open in its basic position (normally open);

FIG. 8 shows a variant of the exemplary embodiment shown in FIG. 7 with improved flow behavior;

FIG. 9 shows a further improved variant of the exemplary embodiment from FIG. 7;

Fig. 10 shows an embodiment as a 3/2-way valve and

Fig. 11, the Sollwerthubkennlinen a conventional 2/2-way valve.

In Fig. 1, a first embodiment of an inventive directional valve 1 is shown, which is designed as an electrically operated 2/2-way cartridge valve in hollow slide valve design.

The directional control valve 1 has a two-part valve housing 2 , with a sleeve 4 and a flange part 6 , on the outer circumference of which a thread is formed for screwing the built-in valve into a valve block or a plate. Sleeve 4 and flange part 6 are penetrated by an axial bore 8 , which is widened step-wise in the region of the flange part 6 . In the flange part-side mouth of the Axialboh tion 8 , an internal thread is provided, into which an electromagnet 10 designed as a proportional magnet is screwed in. In the exemplary embodiment shown, the electromagnet 10 has a screw-in collar 12 which dips into the axial bore 8 of the flange part 6 . A plunger 14 connected to an armature of the electromagnet 10 bears with its free end section against a valve slide 16 which is guided in the sleeve 4 in an axially displaceable manner. In the embodiment shown in Fig. 1, the valve spool 16 has a rear annular collar 18 on which a compression spring 20 engages, which is supported on the adjacent end face 22 of the sleeve 4 , so that the valve slide 16 against the adjacent end face of a screw collar 12 and is biased against the plunger 14 .

The directional valve 1 has a through the front Mün extension of the axial bore 8 port A and a radial star 24 formed Radialan circuit B, which is controlled in the version shown in Fig. 1 in the basic position of the directional valve 1 .

The valve spool 16 designed as a hollow slide has a jacket 28 encompassing an interior 26 , which has multiple jacket openings 30 distributed around the circumference, which in the basic position shown is controlled by a control edge 32 formed by a peripheral edge of an annular space of the radial connection B, so that the Connection between ports A and B is blocked.

In the valve sleeve 4 , a housing bore 36 is formed, which on the one hand opens into the left end face of the connection A in FIG. 1 and on the other hand into the right, flange partial end face 22 of the sleeve 4 , so that the end face area of the sleeve 4 with the through limited the radially enlarged part of the axial bore 8 of the flange part 6 and the end face 22 , the compression spring 20 accommodates the spring chamber 38 . In the embodiment shown in Fig. 1 Darge, the housing bore 36 is through an angular bore with an axially spaced to the valve axis leg 40 and a bore designed as an oblique bore in the rear spring chamber 38 open the leg. Such a housing bore 36 can be manufactured in an extremely simple manner from the end faces by drilling.

To tap the pressure at the working port A, a radial groove 44 is provided in the end face 34 , which extends from the axial bore 8 to the axially extending angle 40 of the housing bore 36 . Through the housed bore 36 , the pressure prevailing in the mouth region of the axial bore 8 in the rear spring chamber 38 is detected, in which the right-hand end portion of the valve slide 16 is arranged in FIG. 1, so that its end faces, which are effective in the opening and closing direction, approximately also with are subjected to the same pressure - the actuating forces for the electromagnet 10 are thus reduced to a minimum. When the electromagnet 10 is actuated, an axial position of the valve slide 16 is established , which depends essentially on the compressive force of the compression spring 20 , the actuating force of the electromagnet, the pressure at the connections A, B and the flow forces acting on the valve slide 16 . These flow forces can reach a considerable, not negligible order of magnitude in particular when flowing through the 2/2-way valve 1 from the radial connection B in the direction of the axial connection A - as mentioned at the beginning.

To actuate the directional control valve 1 , the electromagnet 10 is activated, so that the valve slide 16 via the tappet 14 against the force of the compression spring 20 according to FIG. Is moved as shown in Fig. 1 to the left. During this axial displacement of the valve slide 16 , the jacket openings 30 are opened via the control edge 32 , so that the front connection A is hydraulically connected to the radial connection B. The pressure in the spring chamber 38 is tapped at a comparatively large axial distance from the casing bores 30 , so that the influence of the flow forces compared to the conventional solutions in which the pressure was simply reported into the spring chamber 38 through an inner bore of the valve slide 16 opening into the interior 26 , is significantly reduced. A sudden tearing open of the valve at high flow rates and pressure differences over the directional control valve 1 can thus be reliably prevented. In this way, the effective, the pressure difference-determining throttle cross-section of the 2/2-way valve 1 can be given very precisely via the electromagnet 10 , the volume flow characteristics when flowing through the working connection A to the working connection B and in the opposite direction are almost identical - on these characteristics will be discussed in more detail below.

The problem with the above-described solution is that the housing bore 36 crosses the radial bore star 24 , so that a very precise bore guidance is required, in particular in the case of small nominal sizes, in order to prevent these channels from being cut and thus short-circuited.

This problem can be reduced with the embodiment shown in FIG. 2. This Ausführungsbei game has the same basic structure as the directional control valve 1 shown in Fig. 1, so that for simplicity, mutually corresponding components are provided with the same reference characters and will be omitted on a repeated description of these identical components. In the embodiment shown in FIG. 2, the radial bore star of the radial connection B is formed by three axially offset bore stars 46 , 48 , 50 , which open into a common annular space 52 . The housing bore 36 is made at an axial distance from the valve axis and it extends as a straight bore from the end face 34 to the end face 22 of the sleeve 4 which delimits the spring space 38 .

Due to the large number of radial bores in connection B, it is practically inevitable that the housing bore 36 intersects the bore stars 46 , 48 , 50 . In order to prevent a short circuit between the connections A and B, a sealing tube 54 is inserted from the end face 34 in the area of intersection between the bore stars 46 , 48 , 50 and the housing bore 36 , so that the housing bore 36 relative to the bore stars 46 , 48 , 50 is sealed. In the illustrated embodiment, the housing bore 36 is formed as a stepped bore, wherein the sealing tube 54 is inserted into a radially expanded section and thus bears against a radial shoulder. The sealing tube 54 can be accommodated with a press fit in the housing bore 36 , so that the manufacturing outlay is minimal.

In Fig. 3, an embodiment is shown in which the manufacturing outlay compared to the previously described solutions is reduced again. The basic construction of the valve shown in Fig. 3 corresponds to that of Fig. 2. That is, in the sleeve 4 zueinan offset bore stars 46 , 48 , 50 are formed, which open into the annular space 52 . In contrast to the above-described solutions, the pressure effective in the area of connection A is not reported via a housing bore, but rather via an inner bore 56 of the valve slide 16 in the rear spring chamber 38 . This inner bore 56 opens on the one hand in the interior 26 and on the other hand via Radialboh tion 58 in the spring chamber 38 . In order to minimize the influence of the large flow forces, particularly in the deflection area of the pressure medium, a tube 60 is inserted into the radial bore, which passes through the interior 26 and extends in the direction of the end face 34 of the sleeve 4 - or as shown in FIG. 3 - beyond , so that the effective pressure in the spring chamber 38 in a large axial distance. the man breakthroughs 30 is tapped.

In Figs. 4 and 5 show a further execution example of the invention 2/2-way valve Darge provides, in which the influence of the flow forces with respect to the solutions described above is to be again reduced. FIGS. 4 and 5 show sectional views of the directional control valve 1, the basic structure back to that of FIG. 1 corresponds. Provided in the sleeve 4 is a housing bore 36 in the form of an angular bore, via which the pressure at the axial connection A in the rear spring chamber 38 is reported. In contrast to the above-described exemplary embodiments, the interior 26 of the valve slide valve 16 is axially extended in the direction of the collar 18 , so that the area between the jacket openings 30 and an inner end face 62 of the interior 26 has a greater axial length than in the previously described exemplary embodiments. In this area, a housing-fixed inner piston ben 64 is provided, on the outer circumference of which the valve slide is guided in a sealing manner over 16 . A damping space 66 delimited by the end face of the inner piston 64 and the inner end face 62 is connected to the spring chamber 38 in the illustrated embodiment, via a throttle bore 67 in the jacket of the valve spool 16 , so that essentially the same pressure in this and in the damping chamber 66 , ie the pressure at the working port A is present.

As shown particularly in Fig. 5 can be seen, the inner piston 64 is anchored by a pin 68 in the sleeve 4. This pin 68 passes through the inner piston 64 and the jacket of the valve spool 16 in the radial direction, the two end sections being received in radially extending bearing bores 70 of the sleeve 4 . In order to allow the axial displacement of the valve spool 16 relative to the housing-fixed inner piston 64 , 16 elongated holes 72 , 74 are formed in the jacket of the valve spool, which are penetrated by the pin 68 . By this construction, the inner piston 64 is on the sleeve 4 and thus abge supported on the valve housing, while the valve spool is continued 16 axially ver slidable in the axial bore 8 and a sealing manner on the outer circumference of the inner bulb 64th The pressure at the front port A is guided through the housing bore 36 , the spring chamber 38 and the throttle bore 67 into the throttle chamber 66 , so that the inner end face 62 is acted upon by the pressure prevailing at the front end of the port A.

The flow and jet forces caused in particular in the area of the jacket breakthroughs 30 by the deflection and the pressure difference across the Dros selquerschnitt are introduced into the sleeve 4 via the inner piston 64 and the pin 68 , so that the interactions with the valve slide 16 are minimal. The influence of high-frequency pressure fluctuations in the throttle chamber 66 can be damped by the throttle bore 67 , so that an optimal response behavior of the directional control valve 1 is ensured.

In Fig. 6, the characteristics of such an opti mized 2/2-way valve are shown. The setpoint stroke characteristics show that the discontinuities that can be seen in the conventional solutions ( FIG. 11) practically no longer occur. The characteristic curves have an almost ideal, linear course, with no tendency to tear open. In the illustration according to FIG. 6, the pressure differences Ap rise in the direction of arrow on the directional valve. At higher pressure differences Δp, as can be seen from the flattening of the characteristic curves, there is a tendency to close the valve so that the flow forces act on the valve slide in the closing direction. Such behavior is much easier to control than the tendency to tear open with conventional solutions. The characteristic curves shown in FIG. 6 are practically identical in the solutions according to the invention for a flow from port A to port B and in the reverse direction, so that the consumer can be controlled in an optimal manner.

The above-described embodiments are carried out in a construction in which the directional control valve is closed when the solenoid is not energized (closed when de-energized). The inventive concept with the tapping of the control oil (pressure medium) at a distance from the end face of the valve spool 16 can of course also be realized with Wegeven valves 1 , which are open when the electromagnet is de-energized (open when de-energized). Such Ausführungsbei games are explained with reference to FIGS. 7 to 9.

The basic structure of the embodiments shown in FIGS . 7 to 9 corresponds to the valve shown in FIG. 1, so that only the differences are dealt with here.

In principle, the construction of a normally closed valve can be transferred to a normally open valve in which the jacket openings 30 in the valve slide 16 are displaced axially to such an extent that they are hydraulically connected to the radial bore star 24 in the basic position and this connection is controlled in the event of an axial displacement become. That is, similar to the embodiment indicated in FIG. 7, the jacket openings 30 are shifted to the left compared to the illustration in FIG. 1.

Preliminary tests showed that such a solution still shows certain discontinuities in the flow behavior at large pressure differences. In order to eliminate these discontinuities, in the exemplary embodiment shown in FIG. 7, a connecting channel 76 is formed parallel to the connecting bore 36 in the valve housing 2 in the valve slide 16 , which opens on the one hand in the interior 26 of the valve slide 16 and on the other hand in the spring chamber 38 . The diameter of this connecting channel 76 is larger than that of the housing bore 36 selected.

In the exemplary embodiment shown in FIG. 7, the connecting channel 76 has an axial section 78 which merges into at least one radial section (perpendicular to the plane of the drawing in FIG. 7) 80 opening into the spring chamber 38 . Such a connecting channel 76 can thus be formed without wide res through axial and radial bores. The diameter of the radial section 80 is selected to be comparatively small, so that it acts as a nozzle.

Similar to the above-described Ausführungsbei play the radial bore star 24 opens into an annular groove 82 which is formed on the inner circumferential wall of the axial bore 8 . The axial position of the jacket openings 30 is selected such that they are controlled by an edge 84 of the annular groove 82 when the valve slide 16 is axially displaced, so that the connection from the connection A to the connection B is closed.

In the variant shown in FIG. 8, the Ven slide valve 16 also has a connecting channel 76 through which the interior 26 of the valve slide 16 is connected to the rear pressure chamber, ie the spring chamber 38 .

In contrast to the above-described embodiment, the piston bore 86 forming the interior 26 is lengthened in the axial direction, so that the section 78 is correspondingly shortened.

Similar to the example shown in Fig. 1, for example approximately exporting the connecting bore 36 of the sleeve 4 opens into an end surface 22. This mouth lies in the region in which the end face 22 is penetrated by the valve slide 16 . Cross bores 90 are formed in the valve slide, which on the one hand open into the piston bore 86 and on the other hand on the outer circumference of the valve slide 16 .

In an axial displacement of the valve spool 16 in the direction away from the magnet, the transverse bores are fed by a control edge 92 90, which is formed by a circumferential groove 94 of the sleeve 4 in the mouth region. In the case of an axial displacement by the dimension T, the control cross section is completely closed. In other words, in the basic position (open when de-energized), an additional control cross section is opened, which has a substantially larger diameter than that of the radial section 80 and the connecting bore 36 .

As further indicated in Fig. 8, triangular-shaped control windows 30 can be formed in place of the circular jacket openings, so that the tax-controlled cross-section increases rapidly with increasing axial displacement.

With the variant shown in FIG. 8, the discontinuities in the flow behavior can be further reduced compared to the previously described solutions.

Fig. 9 shows a preferred embodiment of a valve in a normally open design, which is characterized by an extremely simple structure and optimal flow behavior.

In the illustrated embodiment, the Ven tilschieber 16 has a piston bore 86 which has approximately the same length as the piston bore 86 and the Axialab section 76 together from the embodiments shown in FIGS . 7 and 8 Darge.

In the area of the end portion of the axially extending piston bore 86, one or more radial sections 80 are formed on the loading of the piston bore 86 bordered inner space 26 is connected to the spring space 38th

Similar to the example shown in FIG. 2, the housing bore 36 is axially parallel and forms in the end face 22 of the sleeve.

Furthermore, in this preferred embodiment, the radial bore star 24 , which can be formed from mutually offset individual bores, opens directly into the axial bore 8 and not — as in the previously described exemplary embodiments — in an annular groove 82 of the sleeve 4 . In other words, the radial bore star 24 is opened or closed directly by the peripheral edge 96 of the valve slide 16 which acts as a control edge.

The illustrated embodiment is particularly easy to manufacture, since the axial bore 8 can be carried out essentially continuously without an annular groove 82 and the housing bore 36 can also be produced in a single operation. The valve slide 16 is extremely simple, since no stepped holes as in the embodiments shown in FIGS . 7 and 8 must be provided in its interior.

Of course, in the embodiment shown in FIG. 9, instead of the radial bore star 24 with circular jacket bores, another geometry, for example the triangular control window shown in FIG. 8, can be selected.

In the exemplary embodiments described above, the directional valve is designed as a 2/2-way valve. Of course, the invention is also applicable to designs with multiple connections. Fig. 10 shows a variant in which the directional control valve is designed with 3 connections. In the illustrated variant, an axial connection A, a formed by two radial bore stars 98, 100 and a circumferential annular groove 102. Radial terminal are B and formed a through sheath holes 104 of the housing 6 and aligned therewith openings 106 of the sleeve 4 in the inserted into the valve housing 6 sleeve 4 Another radial connection C. The valve spool 16 - like the exemplary embodiments described above - has an interior space 26 formed by a blind hole in which jacket openings 30 of the valve spool 16 open. The valve slide shown has two ring collars 108 , 110 in the section guided in the axial bore 8 . The ring end faces of these two ring collars 108 , 110 are designed such that in the basic position of the valve slide 16 , in which it is biased against a stop by the compression spring 20 , the two connections B and C are connected to one another via an annular space 112 . The spring chamber 38 which receives the compression spring 20 is connected via a housing bore 36 to the region which is adjacent to the end face 34 of the sleeve 4 . The valve shown in FIG. 10 is actuated via a proportionally adjustable magnet or via a switching magnet, the plunger 14 of which bears against the right-hand end face of the valve slide 16 in FIG. 10. In the basic position shown, the jacket openings 30 of the valve slide 16 are closed by the web between the two radial bore stars 98 , 100 , so that there is no connection between the front connection A and one of the radial connections B, C.

When the electromagnet is actuated, the valve slide 16 is displaced to the left against the force of the compression spring 20 , so that a control edge 114 formed by the annular end face of the annular collar 110 controls the connection C, while a control edge 116 formed by the circumferential edge of the jacket opening 30 opens the radial bore star 98 , so that the connection from the front connection A to the radial connection B is opened. In the spring chamber 38 of the compression spring 20 , that pressure always acts that is tapped at a distance from the valve slide 16 via the housing bore 36 . In the illustrated embodiment, the housing bore 36 is formed as a straight through bore, of course - depending on the structure of the valve housing - the above-described variants can also be used to tap the pressure in the spring chamber.

The variants described can be designed as normally open or normally closed valves. Of course, the directional valves 1 described above can also be designed as seat valves.

A directional control valve with an end face is disclosed Connection and at least one radial connection, the End faces of a valve body (valve slide or Seat body) of the directional control valve at approximately the same pressure are applied, so that the actuating forces to move of the valve body are minimal. According to the Pressure to apply to a rear face of the Valve body tapped at an axial distance from the valve body.  

LIST OF REFERENCE NUMBERS

1

way valve

2

valve housing

4

shell

6

flange

8th

axial bore

10

electromagnet

12

Einschraubbund

14

tappet

16

valve slide

18

collar

20

compression spring

22

face

24

Radial bore star

26

inner space

28

coat

30

Coat breakthrough

32

control edge

34

front

36

housing bore

38

spring chamber

40

Leg (axial)

42

Leg (oblique)

44

radial groove

46

Hole Star (B)

48

Hole Star (B)

50

Hole Star (B)

52

annulus

54

tight tube

56

internal bore

58

radial bore

60

tube

62

Inside face

64

internal piston

66

damping space

67

throttle bore

68

pen

70

location hole

72

.

74

Long hole

76

connecting channel

78

axial

80

radial section

82

ring groove

84

control edge

86

piston bore

90

cross hole

92

control edge

94

circumferential groove

96

control edge

98

Radial bore star

100

Radial bore star

102

collar

104

jacket bore

106

breakthrough

108

collar

110

collar

110

annulus

114

control edge

116

control edge

Claims (15)

1. Directional control valve, in particular a continuously adjustable directional control valve with a valve body ( 16 ) guided in a valve bore ( 8 ) of a housing ( 4 , 6 ), via which a connection between an end connection (A) and at least one radial connection (B) is opened and closed can be controlled, the pressure acting on a connection (A) being conducted via a connecting bore to the rear of the valve body, characterized in that the pressure is tapped at a distance from the valve body ( 16 ) in the region of the front connection (A). 2. Directional control valve according to claim 1, wherein the Ventilkör by ( 16 ) is cup-shaped and in the jacket ( 28 ) jacket openings ( 30 ) for connection of the gene stirnseiti connection (A) with the radial connection (B) are formed. 3. Directional control valve according to claim 2, wherein the Ventilkör by ( 16 ) has an inner bore ( 56 ) which opens on the one hand in a rear pressure chamber ( 38 ), and in which a tube ( 60 ) is inserted, which is from the inner bore ( 56 ) extends away from the valve body ( 16 ) towards the front connection (A). 4. Directional control valve according to claim 1 or 2, with a housing channel ( 36 ) which opens on the one hand in the area of the stirnsei term connection (A) and on the other hand in the rear pressure chamber ( 38 ). 5. Directional control valve according to claim 4, wherein the Gehäuseeka channel ( 36 ) is designed as an angled bore and in the end face ( 34 ) of the axial connection (A) opening leg = 40 ( 40 ) as an axially parallel bore and a leg opening in the pressure chamber ( 38 ) ( 42 ) is designed as an oblique bore. 6. Directional control valve according to claim 4 or 5, wherein the housing channel ( 36 ) intersects at least one radial bore of the Ra dial connection (B) and a sealing tube ( 54 ) is used in the cutting area. 7. Directional control valve according to one of claims 4 to 6, wherein the valve body ( 16 ) has a connecting channel ( 76 ) which on the one hand in the connection-side end face of the valve body ( 16 ) and on the other hand opens into the rear pressure chamber ( 38 ). 8. Directional control valve according to claim 7, wherein the connec tion channel ( 76 ) has an axial section ( 78 ) which merges into radial sections ( 80 ) opening into the rear pressure chamber ( 38 ). 9. Directional control valve according to claim 8, with transverse bores ( 90 ), via which an additional flow cross-section to the pressure chamber ( 38 ) can be opened or closed after an axial displacement of the valve body ( 16 ). 10. Directional control valve according to one of the preceding claims, wherein the radial connection (B) leads via a radial bore star ( 24 ) into the valve bore ( 8 ) of the housing ( 4 , 6 ). 11. Directional control valve according to one of the preceding claims che, which is normally open or normally closed is executed. 12. Directional control valve according to one of the preceding claims, wherein in an interior ( 26 ) of the valve body ( 16 ) a housing-fixed inner piston ( 64 ) is guided, which is arranged in the area between the jacket openings ( 30 ) and an inner end face ( 62 ) of the valve body , and with the valve body ( 16 ) delimits a damping chamber ( 66 ) which is connected to the rear pressure chamber ( 38 ). 13. Directional control valve according to claim 12, wherein in the jacket ( 28 ) of the valve body ( 16 ) a throttle bore ( 67 ) is formed, which opens out on the one hand in the rear pressure chamber ( 68 ), on the other hand in the damping chamber ( 66 ). 14. Directional valve according to claim 12 or 13, wherein the inner piston ( 64 ) via an at least one slot ( 72 , 74 ) of the valve body ( 16 ) penetrating pin ( 68 ) is fixed in the housing ( 4 , 6 ). 15. Directional control valve according to one of the preceding claims, wherein the valve body is a valve slide ( 16 ), which is preferably actuated via an electromagnet ( 10 ).