EP1996820A1

EP1996820A1 - Hydraulic valve arrangement

Info

Publication number: EP1996820A1
Application number: EP07703334A
Authority: EP
Inventors: Wolfgang Kauss; Vincenzo Domenico Bollero
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2006-03-14
Filing date: 2007-02-08
Publication date: 2008-12-03
Anticipated expiration: 2027-02-08
Also published as: JP2009529635A; US20090217983A1; DE502007001358D1; WO2007104391A1; EP1996820B1; DE102006012030A1; JP4988775B2; ATE440221T1

Abstract

The invention relates to a hydraulic valve arrangement which is used, in particular, for a mobile machine and which has a valve housing (10) having a feed channel (34), having an outlet channel (42) and having a consumer channel (39) and has a valve bore (11) which cuts into the channels. In the valve bore (11), a valve slide (12) can be moved axially from a neutral position in at least one direction into a working position, by way of which valve slide (12) the fluidic connections between the channels can be controlled. Moreover, there is a pressure-relief and feed valve (45, 47), by way of which the pressure in the consumer channel (39) can be limited by throttled discharge of pressure fluid into the outlet channel (42) and pressure fluid can be fed from the outlet channel (42) into the consumer channel (39). The invention is based on the object of designing a hydraulic valve arrangement of this type in such a way that low manufacturing costs and a small overall size are possible. According to the invention, the object which is aimed at is achieved by the pressure-relief and feed valve (45, 47) being accommodated in a hollow space of the valve slide (12).

Description

description

Hydraulic Ventilanordnunq

The invention relates to a hydraulic valve arrangement, which is used in particular for controlling hydraulic consumers on mobile machines and having the features of the preamble of patent claim 1.

Such a valve arrangement is known, for example, from DE 199 48 232 A1, DE 103 25 294 A1, EP 1 092 095 B1 or from the data sheet RD 64 295 / 07.02 or the data sheet RD 64 282 / 05.00 by the applicant and can be regarded as single valve disc, which can be assembled with another valve disc to a control block, or be designed as a valve disc of a so-called monoblock. The valve discs from the cited Vorveröffentlichungen are designed as so-called load-sensing valves and contain in a valve bore of a valve housing a valve spool, with which the opening cross-section of a metering orifice and the flow direction of the pressurized fluid in the existing consumer channels can be controlled.

In the valve housings also a pressure compensator is housed in a further bore, which is arranged at the valve disc according to the data sheet RD 64 282 / 05.00 upstream of the metering orifice and the control piston in the closing direction of the pressure before the metering orifice and in the opening direction of the pressure to the metering orifice and a spring is acted upon. In the valve discs according to the other Vorveröffentlichungen the pressure balance is located downstream of the metering orifice and is acted upon in the closing direction of the highest load pressure of all simultaneously actuated hydraulic consumers and in the opening direction of the pressure to the metering orifice. Such valve discs enable a load pressure-independent flow distribution, if at the same time several hydraulic consumers are to be supplied with pressurized fluid and the pumped by a pump amount of pressurized fluid is less than the requested amount of pressurized fluid.

Furthermore, the known valve disks in the valve housing contain two pressure limiting and feed valves, one of which is assigned to one of the two consumer channels. Such a pressure limiting and feed valve responds regardless of the position of the valve spool when the pressure in the corresponding consumer channel reaches a certain value and limits the pressure to this value by throttling pressurized fluid from the consumer channel throttled to the outlet channel (pressure limiting function). , This can happen, for example, when the valve spool in the neutral position shuts off the consumer channel and that in the consumer channel, in a connected consumer line and in the hydraulic consumer. itself located pressure fluid heated and the hydraulic consumer is located on a stop.

The pressure relief and feed valve also responds when the load is acting in the desired direction of travel and the pressure in the consumer passage, through which hydraulic fluid is supplied to the hydraulic fluid, falls below the pressure in the discharge passage (feed function). The pressure in the outlet channel can be raised above atmospheric pressure with the help of a stowage valve.

It is not always connected to a consumer channel a pressure relief and feed valve. For certain applications it is sufficient that only one of the two consumer channels of a valve disc is assigned a pressure limiting and feed valve. Sometimes a valve disk has no pressure relief and feed valve at all. For the different applications, therefore, one must therefore produce different valve housings and combine them with the correct valve slides during assembly. This causes considerable handling costs. In the cast valve housings, because you do not want to pour different blanks, always provided the installation space for two pressure relief and feed valves. The invention has for its object to further develop a hydraulic valve assembly with the features of the preamble of claim 1, that lower production costs and a smaller size are possible.

The desired goal is achieved in a hydraulic valve assembly with the features of the preamble of claim 1 according to the invention that according to the characterizing part of claim 1, the pressure limiting and feed valve is housed in a cavity of the valve spool. With such a design, the valve housing may be a standard element, the raw shape and further design no longer has to depend on whether the valve disc should contain no, one or two pressure relief and feed valves. At the valve housing, no more space must be provided for the pressure limiting and feed valves, so that it can be smaller than in known valve disks. The different variants of valve discs are formed only towards the end of the manufacturing process through the use of a corresponding valve spool, which is adapted in any case, taking into account other aspects of the particular application. Depending on requirements, the valve spool can accommodate one or two pressure relief and feed valves.

Advantageous embodiments of a hydraulic valve arrangement according to the invention can be found in the subclaims.

Particularly useful in this case appears an embodiment according to claim 3, according to which the valve spool is movable from the neutral position in both directions in working positions and according to which the cavity in the valve spool is connected via a radial bore with the drainage channel, which is so close to one end of the valve spool, that it is closed with a displacement of the valve slide from the neutral position in the sense of a connection of the second consumer channel with an inlet channel to the drainage channel. This embodiment is based on the idea that in a working position the valve spool, in which the consumer channel is connected to the drainage channel, the cavity in the valve spool need not be open to the drainage channel. Accordingly, the radial bore can be placed far outward at the end of the valve spool. A large stroke of the valve spool can be maintained. The control chamber, which forms the flow channel at the valve bore, does not have to be increased axially.

There are different versions of pressure relief and feed valves that can be installed in the valve spool, where the different versions may differ in their length or in the flow area of the feed. Münden according to claim 4 in the cavity chamer channel side two radial bores, which are spaced apart in the axial direction of the valve slide and of which in a working position of the valve spool a radial bore to the consumer channel and the other Radialboh- tion to the inlet channel or to the drainage channel is open, so it is possible to use a particular version of a pressure relief and feed valve, for which the large diameter cavity must reach into a region of the valve spool in which the valve spool of the known valve arrangements for producing the various fluidic connections has an annular groove. According to the embodiment, the cavity is in the fluidic connection of the consumer channel with the inlet channel and the drainage channel. An annular groove is not necessary.

If another version of a pressure relief and feed valve is used, which does not require that the large diameter cavity goes far into the valve spool, and the valve spool according to claim 5 in the region of the consumer channel has an annular groove through which the consumer channel can be connected to an inlet channel or the drainage channel, it leads, as indicated in claim 6, advantageously from the annular groove from a radial bore into the cavity. Through this radial bore pressure fluid flows only when the pressure relief and feed valve responds. The patent claim 7 is directed to a hydraulic valve assembly with a pressure limiting and feed valve, which can be built with a particularly small diameter, so that the wall surrounding the cavity of the valve spool can be so thick that they readily meet all requirements for dimensional stability and breakage is sufficient. The Druckbegren- supply and supply valve according to claim 7 can be further developed in accordance with the claims 8 to 11 in an advantageous manner.

Several trained as LUDV valves embodiments of a hydraulic valve assembly according to the invention are shown in the drawings. Based on these drawings, the invention will now be explained in more detail.

1 shows a longitudinal section through a valve disc with two consumer channels and with a valve spool, in which two differently shaped pressure limiting and feed valves are housed,

2 shows a longitudinal section through a second valve disc with two consumer channels and with a valve slide, in which only one pressure-limiting and feed valve is accommodated according to a third version,

Figure 3 is an enlarged view of the valve disc of Figure 2 in the region of the pressure limiting and feed valve and

FIG. 4 shows a longitudinal section through one of the two pressure-limiting and feed valves from FIG. 1.

The valve disks according to FIGS. 1 and 2 have a disc-shaped valve housing 10, through which passes a valve bore 11 located in a central disc plane. In this, a valve spool 12 is axially movable. In the embodiment of Figure 1, the valve spool is mechanically actuated and has to a projecting out of the valve housing 10 end a two-plane 13 to which a hand lever can be attached. On the other end of the valve spool 12, which also comes from the valve housing 10 forth protrudes, but is covered by a screwed to the valve housing cover 14, a helical compression spring 17 is tied within the lid with two spring plates 15 and 16, which centers the valve spool in a neutral position and with each movement of the valve spool from the neutral position regardless of the direction of movement is more compressed from a basic bias.

In the embodiment of Figure 2, the valve spool is hydraulically actuated. For this purpose, both of the valve housing 10 outstanding ends of the valve spool 12 are covered with solid lids 18 which are bolted to the valve housing 10 and have a connection opening 19 for a control line. With the aid of a hydraulic pilot control device, a control pressure in the one or the other lid can be controlled via the control lines, which generates a force on the cross-sectional area of the valve spool 12, which binds the valve spool so far against the as in the first embodiment between two spring plates 15 and 16 Helical compression spring 17 shifts until there is an equilibrium between the pressure force and the spring force.

The valve bore 11 in both embodiments is surrounded by eight axially spaced apart control chambers, which serve to control the inflow of hydraulic oil from a hydraulic pump to a hydraulic consumer, for example to a hydraulic cylinder, and from the hydraulic consumer to a tank. Between each three control chambers on both sides there are two control chambers 25 and 26 which are fluidically separated from each other in the neutral position of the valve spool 12 shown in FIGS. 1 and 2 by a spool collar 27, to which a spool neck on both sides Ring groove 28 and 29 connects and has two rows of Feinsteuernuten 30 and 31, which are offset in the circumferential direction against each other and of which the fine control grooves 30 to the annular groove 28 and the fine control grooves 31 to the annular groove 29 are open. The control chamber 25 is provided for connection to a pump line and therefore may also be referred to as a pump chamber. The control chamber 26 is an intermediate chamber. Depending on the tion, in which the valve spool 12 moves out of the neutral position, a flow cross-section of the pump chamber 25 to the intermediate chamber 26 is opened by the fine control grooves 30 or by the fine control grooves 31, which forms the metering orifice of the valve assembly.

On one side of the two control chambers 25 and 26 there is an inlet chamber 32 and on the other side an inlet chamber 33. These two inlet chambers are part of a bridge-like inlet channel 34 into which the hydraulic oil from the intermediate chamber 26 passes via a pressure compensator 35. In this connection, only so much is said that their one-piece (FIG. 1) or two-part (FIG. 2) control piston in the closing direction of the highest load pressure of all simultaneously actuated hydraulic consumers and possibly a weak spring and in the opening direction of the pressure in the intermediate chamber 26th is charged. The pressure compensator is thus arranged downstream of the metering orifice and accumulates in the intermediate chamber to a pressure resulting from the respective highest load pressure. The valve arrangements shown in FIGS. 1 and 2 are therefore LUDV valves.

A consumer chamber 36 follows the inlet chamber 32 and a consumer chamber 37 onto the inlet chamber 33. Each consumer chamber is part of a consumer channel 38 or 39 which terminates in a consumer connection of the valve housing 10. Each consumer chamber 36 and 37 is followed by a drain chamber 40 or 41. The two drain chambers are connected to each other in a completed valve block and part of a flow channel 42, which, if appropriate via a backup valve, leads to a tank connection.

In the neutral position of the valve spool 12 all control chambers 25, 26, 32, 33, 36, 37, 40 and 41 are shut off from each other. If the valve spool 12 is moved out of the neutral position, the metering orifice is opened by the fine control grooves 30 or 31. In addition, the one consumer chamber is opened to a feed chamber and the other consumer chamber to a drain chamber. In addition to the components described so far, the valve disk according to FIG. 1 also has two pressure-limiting and feed valves 45 and 46 and the valve disk according to FIG. 2 also has a pressure-limiting and feed-in valve 47. According to the invention, the pressure-limiting and feed valves are each housed in a cavity 48, 49 (FIG. 1) or 50 (FIG. 2) of the valve spool 12. According to Figure 1, the valve spool is equipped with two different pressure relief and feed valves. Of course, it can also have two equal pressure relief and feed valves.

The cavities 48, 49 and 50 are each introduced from an end face of a main part of the valve spool 12 into the main part and closed by a respective end piece 51, 52 or 53 screwed into the main part. In the closed position, the pressure limiting and feed valves separate a drain chamber side, first region of a cavity from a consumer chamber side, second region of a cavity. The first area is open via a radial bore 55 in the valve spool 12 to the outside thereof. The radial bore 55 in turn is in the neutral position and in an adjustment of the valve spool in a direction in which the corresponding consumer chamber 36 and 37 is connected to the associated inlet chamber, to the drain chamber 40 and 41 open. In an adjustment of the valve spool 12 in the other direction, the radial bore 55 is closed after a short path. For the function, this has no effect, since the corresponding consumer chamber via the valve spool is already connected to the drain chamber.

The second region of the two cavities 48 and 49 of Figure 1 is open via two axially spaced rows of radial bores 56 and 57 to the outside of the valve spool out. In the neutral position of the valve spool 12 shown in FIG. 1, the bores 56 and 57 are open towards the respective consumer chamber 36 or 37. Moving the valve spool 12 from the neutral position in the view of Figure 1 to the right, the radial bores 57 of the cavity 48 remain open to the consumer chamber 36, while the radial bores 56 are closed to consumer chamber 36 and opened to the drain chamber 40 out. In addition, the radial bores 56 of the cavity 49 remain open to the consumer chamber 37 and the radial bores 57 of the cavity 49 are closed towards the consumer chamber 37 and opened to the inlet chamber 33. Hydraulic oil can now, coming from the metering orifice and the pressure compensator ago coming from the inlet chamber 33, the radial bores 57, the second region and the radial bores 56 of the cavity 49 of the consumer chamber 37 and from there a hydraulic consumer. From this back flowing hydraulic oil passes through the load chamber 36, the radial bores 57, the second region and the radial bores 56 of the cavity 48 in the discharge chamber 40. Thus, in the embodiment of Figure 1, the second regions of the cavities 48 and 49 in the fluid path of the working fluid and each replace an annular groove on the valve spool. It is advantageous that the cavities can have a large diameter far into the valve slide. This is favorable for accommodating pressure-limiting and feed valves designed in a particular way.

Each of the pressure limiting and feed valves 45, 46 and 47 has a valve body 70, which in the opening direction from the pressure in the corresponding

Consumer chamber and in the closing direction of the pressure in the adjacent drain chamber and a strong helical compression spring 71 whose pressure equivalent may be, for example, 300 bar, is acted upon and opens a flow cross-section of the consumer chamber to the adjacent drain chamber to limit the pressure in a consumer chamber. In addition, each Druckbegrenzungs- and feed valve has a valve body 72 which is acted upon in the closing direction by the pressure in the corresponding consumer chamber and in the opening direction of the pressure in the adjacent drain chamber and a weak helical compression spring 73, the pressure equivalent, for example, 0.5 bar. When the pressure in the load chamber falls below the pressure in the drain chamber by more than the pressure equivalent of the compression coil spring 73, the valve body 72 opens a flow area, so that hydraulic oil from the discharge chamber is fed into the consumer chamber.

In the pressure limiting and feed valve 46 of Figures 1 and 4, the valve body 70 on a guide rod 74 which carries a closing cone 76 after a circumferential groove 75, facing the puncture has a tapered seat surface 77. On the guide rod 74 of the valve body 72 is pushed, which has around the groove 75 around an annular groove and several outgoing from the annular radial bores 78 and the locking cone 76 projects radially beyond and outside the closing cone opposite the seat surface 77 of the closing cone oppositely directed conical seat surface 79 has , After the valve body 72, the helical compression spring 71 is pushed onto the guide rod 74. Behind this, a spring plate 78 is screwed onto the guide rod 74, so that the helical compression spring 71 is clamped between the valve body 72 and the spring plate 78 and pushes the closing cone 76 with its conical seat surface 77 against an inner seat edge of the valve body 72. The seat diameter is equal to the diameter of the guide rod 74. The previously mentioned parts of the pressure limiting and feed valve 46 are thus summarized captive to a unit. Belongs to the valve still the screw compression spring 73 which is arranged after assembly between the spring plate 78 and the bottom of the cavity 46. The seat edge for the seat surface 79 of the valve body 72 is formed on the end piece 51 of the valve spool 12. The tail extends with a hollow portion to about the radial bores 55 of the valve spool 12 into the cavity 46 inside. On an inner edge of the end face of the end piece of the valve body 72 sits in the rest position. The first region of the cavity 46 is thus formed entirely within the end piece 51. For fluid connection to the outside to the radial bores 55 in the main part of the valve spool 12, the end piece at the level of the radial bores 55 outside an annular groove 80 and from this inwardly leading radial bores 81. Between the annular groove 80 and the end face of the end piece 51 is located between this and the inner wall of the valve slide 12, a lying in an annular groove of the end piece sealing ring 82nd In operation, the pressure prevailing in the consumer chamber 36 acts on a surface defined by the diameter of the guide rod 74 to open the valve body 70 in the direction. The helical compression spring 71, which is supported on the valve body 72 on the end piece 51, holds the closing cone 76 of the valve body 70 with the surface 77 on the valve body 72, as long as the pressure in the consumer chamber, taking into account the pressure prevailing in the discharge chamber 40, the pressure equivalent of Spring does not exceed. Once this is the case, the valve body 70, so the guide rod 74 together with the closing cone 76 - in the views of Figures 1 and 4 - moved to the right, so that opens a flow cross-section between the closing cone 76 and the valve body 72 and hydraulic oil throttled out of the consumer chamber 36 flows into the drain chamber 40. The pressure in the consumer chamber 36 is thus limited to the pressure at which the valve body 70 opens.

The valve body 72 remains in the above-described constellation at rest. If, on the other hand, the pressure in the consumer chamber 36 drops below the pressure in the drain chamber 40 by more than the pressure equivalent of the helical compression spring 73, the valve body 70, the valve body 72 and the helical compression spring 71 are displaced as a unit against the helical compression spring 73 until the Guide rod 74 abuts against the bottom of the cavity 46. Between the valve body 72 and the end face of the end piece 51, a flow cross-section through which hydraulic oil can flow virtually unthrottled from the discharge chamber 40 of the consumer chamber 36 opens. Thus, in the consumer chamber 36 and in the lines and consumer spaces connected to it, the formation of a negative pressure is reliably established. avoided.

Also, the pressure limiting and feed valve 45 of Figure 1 has a valve body 70, which serves to limit the pressure, and a valve body 72, which serves the feed. The valve body 72 is formed as a ring with a central opening and is located axially between the radial bores 55 and 56 of the valve spool 12. It is at an inner shoulder of the weak Helical compression spring 73, which is also supported on a shoulder of the cavity 49, acted upon in a direction out of the cavity. In an outer annular groove of the valve body 72 is a sealing ring 83. From a rest position, which is shown in Figure 1, the valve body 72 can be moved against the force of the helical compression spring 73 against a further shoulder of the cavity 49, wherein in the position that the valve body 72 then occupies, the radial bores 56 remain open to the cavity 49.

The valve body 70 of the pressure limiting and feed valve 45 comprises a closing cone 85, which is located in the drain chamber side region of the cavity 49 and can seat with a tapered surface on an edge of the central opening of the valve body 72, a stop finger 86 which is on the tail 52 assigns, the strong coil spring 71, the stop finger 86 surrounding clamped between the closing cone 85 and the end piece 52, and a support rod 87, which passes through the valve body 72, inside the helical compression spring 73 extends and beyond the radial bores 57 in an end portion of the cavity 49 is immersed and the closing cone 85 is supported in the rest position against the action of the helical compression spring 71 on the valve spool 12. The advantage here is that with a suitable choice of the sealing of the cavity through the end piece 52, the bias of the helical compression spring 71 by turning the _. in the main part of the valve spool 12 screwed end piece 52 can still be changed after the installation of the pressure relief and feed valve 45.

In the rest position of the two valve bodies 70 and 72 and without pressures in the chambers 37 and 41, the valve body 72 is under the action of the helical compression spring 73 against the closing cone 85 of the supported via the support rod 87 on the valve spool 12 valve body 70. The valve body 72 has a small distance from a stop ring 88 inserted into the valve slide, which limits the path of the valve body 72 to the radial bores 55 to before. In operation, when the valve spool is in the neutral position or in a working position in which the consumer chamber 37 is fluidly connected to the inlet chamber 33, the consumer chamber pressure prevailing in the consumer chamber 37 acts on the valve bodies 70 and 72 against the helical compression spring 71 and against a possibly present in the drain chamber back pressure. The first effective area for the consumer chamber pressure is initially determined by the diameter of the valve body 72. If the consumer chamber pressure increases to such a value that the pressure force generated on the first active surface reaches the force of the helical compression spring 71, the valve bodies are moved until the valve body 72 reaches the stop ring 88. From this point on, the consumer chamber pressure can only generate a pressure force on the valve body 70 directed against the force of the helical compression spring 71 at an area defined by the diameter of the central opening in the valve body 72. If the consumer chamber pressure now reaches the value specified by the prestressing of the helical compression spring 71, the valve body 70 lifts away from the valve body 72, so that a flow cross-section between the closing cone 85 of the valve body 70 and the valve body 72 opens and hydraulic oil from the consumer chamber 37 throttles into the discharge chamber 41 flows out. The pressure in the consumer chamber 37 is thus limited to the pressure at which the valve body 70 lifts off from the valve body 72.

If, on the other hand, the pressure in the consumer chamber 37 drops below the pressure in the discharge chamber 41 by more than the equivalent pressure of the helical compression spring 73, then the valve body 72 is lifted against the helical compression spring 73 by the closing cone 85 of the valve body 70 supported by the rod 87 and counteracted already mentioned shoulder of the valve spool pressed. Between the valve body 72 and the closing cone 85 opens a flow cross section, can flow through the hydraulic oil almost unthrottled of the discharge chamber 41 of the consumer chamber 37. The helical compression spring 73 is still far from being compressed to block, so that the hydraulic oil 56 can flow freely to the radial bores. The pressure limiting and feed valve 47 according to Figures 2 and 3 corresponds to the basic structure of the valve 45 of Figure 1. In particular, the valve body 72 with the seal 83 is the same as in Figure 1. The arrangement of a helical compression spring 73 and a stop ring 88 for the valve body 72 are struck as in the valve 45 of FIG.

The valve body 70 is differently designed. The latter now has a collar 90 which is to be oriented in the direction of the end piece 53 and which is offset radially outwards relative to a closing cone 89, with which it contacts the radial force bores 55 on the one hand in the direction of the action force of the helical compression spring 71 Shoulder 91 of the valve spool 12 and on the other hand against the action of the helical compression spring 71 may abut the end piece 53. The possible path of the valve body 70 results in the representation of Figures 2 and 3 by the clearance of the collar 90 from the tail 53rd

The pressure-limiting and feed valve 47 according to FIGS. 2 and 3 is distinguished from the valves 45 and 46 by the fact that its components are arranged less deeply in the valve slide 12 and therefore also the dimensions of the cavity 50 for accommodating the valve 47 are smaller those of the cavities 48 and 49 may be from FIG. The valve spool 12 of the embodiment according to Figures 2 and 3 is provided not only in the consumer chamber 36, but also in the consumer chamber 37 with an annular groove 94, which serves the fluidic connection of the consumer chamber 37 with the inlet chamber 33 and the drain chamber 41 , The connection to the inlet chamber 33 is made via a circumferential edge and the connection to the drainage chamber 41 via drain grooves 95.

The cavity 50 extends as a bore with a relatively small diameter into the region of the annular groove 94, where it is open to the annular groove via the radial bores 57 which open into the annular groove. Unlike in the embodiment of Figure 1, the radial bores 57 are now not in the normal fluid path of the consumer chamber 37 from the inlet chamber 33 flowing or from the Consumer chamber 37 to the drain chamber 41 flowing away hydraulic oil. Radial bores corresponding to the radial bores 56 of the embodiment of Figure 1 are not present in the embodiment of Figures 2 and 3.

In pressure-limiting function, hydraulic oil flows from the consumer chamber 37 via the radial bores 57, the second region of the cavity 50, a throttle cross-section between the valve bodies 70 and 72, the first region of the cavity and via the radial bores 55 to the discharge chamber 41 down. In the feed function, the hydraulic oil takes the opposite route, but the flow area between the two valve bodies 70 and 72 wide open and the pressure drop between the drain chamber 41 and the consumer chamber 37 is low.

Claims

claims

1. A hydraulic valve assembly, in particular for a mobile work machine, with a valve housing (10) having an inlet channel (34), a drain channel (42) and a consumer channel (39) and a valve bore (11), which channels cuts, with a in the valve bore (1 1) from a neutral position in at least one direction to a working position axially movable valve slide (12) with which the fluidic connections between the channels are controllable, and with a pressure relief and feed valve (45, 47), with which the pressure in the consumer channel (39) can be limited by throttled discharge of pressurized fluid into the discharge channel (42) and pressurized fluid can be fed from the discharge channel (42) into the consumer channel (39), characterized in that the pressure limiting - andΕinspeiseventil (45; 47) in a cavity (49; 50) of the valve spool (12) is housed.

2. Hydraulic valve arrangement according to claim 1, characterized in that the valve housing (10) has a second consumer channel (38), that the valve slide (12) from the neutral position in both directions in working positions is movable and has a second cavity (48) and in that a second pressure limiting and feed valve (46) is accommodated in the second cavity (48), with which the pressure in the second consumer channel (38) can be limited by throttling discharge of pressurized fluid into a discharge channel (42) and pressurized fluid from the discharge channel (38). 42) in the second consumer channel (38) can be fed.

3. Hydraulic valve arrangement according to claim 1 or 2, characterized in that the valve slide (12) from the neutral position in both directions in working positions is movable and that the cavity (48, 49, 50) in the valve slide (12) with the drain channel (42) via a radial bore (55) is connectable, which in a displacement of the valve spool (12) from the neutral Position in the sense of a connection of the consumer channel (38, 39) with the drainage channel (42) is closed to the drainage channel.

4. Hydraulic valve arrangement according to one of claims 1 to 3, character- ized in that in the cavity (48, 49) consumer channel side two radial bores (56, 57) open, which are spaced apart in the axial direction of the valve slide (12), and that in a working position of the valve spool (12), a radial bore (56, 57) to the consumer channel (38, 39) and the other radial bore (57, 56) to the inlet channel (34) and to the outlet channel (42) is open.

5. Hydraulic valve arrangement according to one of claims 1 to 3, characterized in that the valve slide (12) in the region of the consumer channel (39) has an annular groove (94) via which the consumer channel (39) with the inlet channel (34) or Drain channel (42) is connectable.

6. A hydraulic valve assembly according to claim 5, characterized in that of the annular groove (94) from a radial bore (57) into the cavity (50) with the pressure limiting and feed valve (47).

7. Hydraulic valve arrangement according to one of claims 1 to 6, characterized in that a pressure limiting and feed valve (45, 47) has a first movable valve body (70) and a second movable valve body (72), of which a closing cone ( 85, 89) and the other than on the closing cone attachable valve seat is formed, one of which is acted upon by a strong spring (71) and the other by a weak spring (73) in the direction of the respective other valve body and which are movable to open the pressure limiting and feed valve (45, 47) against the force of the respective spring in opposite directions, and that the movement of the valve body (70, 72) is limited to each other by slide-fixed stops (88, 91) whose Distance from each other is dimensioned such that the of the weak spring (73) acted upon valve body (72) a small distance to its slide-fixed stop (88), when the of the strong spring (71) acted upon valve body (70) abuts against its slide-fixed stop (91) and on it the other valve body (72) is seated.

8. A hydraulic valve arrangement according to claim 7, characterized in that the valve body (70) with the closing cone (89) at a distance from the valve seat has a radially outwardly offset stop collar (90).

9. Hydraulic valve arrangement according to claim 7 or 8, character- ized in that the movement of the one valve body (70) deeper in the

Valve spool (12) into and on the other valve body (72) to be limited slide-fixed stop (91) is formed by a shoulder in the cavity (50).

10. Hydraulic valve arrangement according to one of claims 7 to 9, character- ized in that the closing cone (85) via a through the valve seat

(72) passing rod (87) is supported on a slide-fixed stop.

1 1. Hydraulic valve arrangement according to one of claims 7 to 10, character- ized in that between the outside of the valve seat (72) and the wall of the cavity (49, 50) a seal (83) is arranged.