WO2001021992A1

WO2001021992A1 - Seat valve

Info

Publication number: WO2001021992A1
Application number: PCT/DE2000/002946
Authority: WO
Inventors: Horst Rott
Original assignee: Mannesmann Rexroth Ag
Priority date: 1999-09-21
Filing date: 2000-08-28
Publication date: 2001-03-29
Also published as: DE19945183A1

Abstract

Disclosed is a directly actuated seat valve with a pressure-compensated valve shaft, whereby the spring chamber (50) for at least one valve body (24, 25) is linked to a pressure connection (P) via a connecting duct (54) which is arranged in an oblique position with respect to the valve, whereby it intersects with the spring chamber. According to said embodiment, radial ducts for hydraulic connection of the spring chamber are no longer required, thereby reducing production costs compared to conventional solutions.

Description

description

poppet valve

The invention relates to a seat valve according to the preamble of patent claim 1.

Directional seated valves of the generic type are disclosed in the publication "Der Hydrauliktrainer", Volume 1, Mannesmann Rexroth GmbH, 2nd edition, 1991, pages 203 ff.

In these seat valves, one or more seat pistons, for example in the form of balls, cones or plates, are arranged in an axially displaceable manner in a housing bore. With increasing working pressure, these seat pistons are biased with greater force against an assigned valve seat, so that the tightness increases. These poppet valves are characterized by low leakage, long service life, the possibility of a locking function without additional locking elements and their use even under high pressure.

Due to the static and dynamic forces acting on them, the seat valves are directly actuated with small nominal diameters, the actuation generally being carried out via an electromagnet. For nominal sizes over 10, indirect actuation is preferred for reasons of switching reliability and difficult to control pressure surges.

The generic seat valves can be designed, for example, as a 2-way valve or as a 3-way valve, one or more balls being used as the seat body (1-ball valve, 2-ball valve).

In the known solutions, the valve body is a

Prestressed compression spring against a valve seat. Between the compression spring and the valve body there is an axially slidable sliding body in the valve bore, which has an outer circumference Seal carries. The connecting channel generally extends from the spring chamber to a pressure chamber adjoining the valve seat.

With these valves, the valve axis can be pressure-balanced so that the switching forces are minimal. However, this requires that, for example, the pressure in the spring chamber adjacent to the sliding body is guided via connecting channels in the valve housing to the other side of the valve axis, so that both sides of the valve axis are subjected to approximately the same pressure. The formation of these connecting channels requires a considerable amount of production engineering, which has a significant influence on the total production costs.

In contrast, the invention has for its object to provide a seat valve that can be manufactured with minimal manufacturing effort.

This object is achieved by a seat valve with the features of patent claim 1.

The measure of arranging the connecting channel at least in sections at an angle to the valve axis in such a way that it cuts the spring chamber for the valve body can significantly reduce the manufacturing outlay compared to the solutions mentioned at the beginning, since it is not necessary to cut the spring chamber directly to provide a separate, radially extending connecting line between the spring chamber and the connecting channel.

Construction according to the invention makes it possible, for example, to introduce a section of the connecting channel by drilling from an end face of the valve housing, this hole cutting the spring space in the edge region.

In a particularly preferred embodiment, the housing is cartridge-shaped, the pressure connection as Axial connection is made so that the connecting channel extends from the pressure connection end face of the valve to the pressure chamber and cuts the spring chamber lying in between.

Alternatively, the pressure connection can also be designed as a radial connection, the connection channel being closed on the end face by a sealing plug and the pressure connection being connected to the connection channel via a transverse channel introduced from the peripheral surface.

The channels of the seat valve according to the invention are preferably designed so that they can be drilled from the outside from a peripheral portion of the valve housing and, if necessary, can be closed on one side by means of suitable sealing plugs.

In one embodiment of the invention, a sealing body guided in the valve bore is arranged between the compression spring and the valve body, the valve seat being formed on a seat bushing inserted into the valve bore. In a so-called two-ball valve), each valve body is assigned its own valve seat, the compression spring prestressing one of the valve bodies against its valve seat, while the other valve body can be placed on a valve seat assigned to it by actuating an electromagnet.

In this construction, the valve body can be arranged between the two valve seats or - in the axial direction - outside the space delimited by the two valve seats. In the former case, the valve seats are preferably implemented by two seat bushings arranged at an axial distance from one another, while in the latter case a single seat bushing is provided, on the end faces of which the two valve seats are designed.

When using a common seat bushing, a coupling piece extends between the two valve bodies, which has a through Allows flow of the seat bushing, so that pressure medium can flow from one valve seat to a connection.

Between a plunger of the electromagnet and the adjacent valve body, a transmission element can be arranged, which is axially displaceably guided in a seat bushing and is provided with axial channels for the pressure medium.

The seat valve according to the invention can be designed, for example, as a 3/2-way valve or as a 2/2-way valve.

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

In the following preferred embodiments of the invention are explained in more detail using schematic drawings. Show it:

Figure 1 circuit symbols of poppet valves according to the invention, which are designed as 2/2 or 3/2-way valve;

Figure 2 shows an embodiment of a first 2/2-way seat valve according to the invention with an axial pressure connection and which can be brought into its blocking position by actuating an electromagnet;

Figure 3 shows a variant of the seat valve shown in Figure 2 with a radial pressure connection;

FIG. 4 shows an exemplary embodiment of a seat valve which can be brought into its open position by actuating an electromagnet;

Figure 5 shows a variant of the embodiment shown in Figure 5 with a radial pressure connection; Figure 6 shows a 3/2-way seat valve embodiment with an axial pressure connection, which is shut off when the electromagnet is de-energized;

Figure 7 shows a variant of the embodiment shown in Figure 7 with a radial pressure connection;

Figure 8 shows an embodiment of a 3/2-way seat valve, in which an axial pressure connection is shut off when the magnet is switched;

Figure 9 shows a variant of the embodiment shown in Figure 8 with a radial pressure connection and

Figure 10 shows another variant of the 3/2-way valve shown in Figure 8 or 9.

The invention is explained below using the example of directly operated 2/2 and 3/2 directional seated valves. The circuit symbols of the exemplary embodiments described in more detail are summarized in FIG. 1. The poppet valves 1 described are actuated directly by an electromagnet 2 and biased into a basic position via a compression spring 4.

In the P version shown in FIG. 1 a, the poppet valve 1 is in its open position when the electromagnet 2 is not energized, so that the connection between a pressure port P and a tank or work port T (A) is open. When the electromagnet 2 is energized, the seat valve according to FIG. 1 a is brought into its blocking position.

In the basic version of the N version according to FIG. 1 b, the connection between the pressure connection P and the tank / work connection T (A) is shut off and is opened when the electromagnet 2 is energized. In the embodiment of a 3/2-way seat valve 1 indicated in FIG. 1 c, the pressure connection P is shut off in the C version (FIG. 1 c), while a connection between a working connection A and a tank connection T is opened. When the electromagnet is energized, this connection is shut off and the pressure connection is connected to the work connection.

Figure 1 d shows a U version in which the pressure medium can flow from the pressure port P to the working port A in the basic position, while the backflow to the tank port T is blocked. When switching the electromagnet, the working port P is shut off and the connection between the working port and the tank port T to the pressure medium backflow opened.

Figure 2 shows a first Ausführungsbeisp el of a seat valve 1 according to the invention, which is designed as a 2-way valve. The seat valve 1 has a cartridge-shaped valve housing 6, which is screwed into a merely indicated receiving bore 8 of a valve block. The seat valve 1 according to the invention is designed with a pressure connection P and a further connection, for example a tank connection T or a work connection. The pressure port P opens axially in the receiving bore 8, while the tank port T opens into a radially extending tank channel of the valve block.

The valve housing 6 is radially downgraded from the right end section in FIG. 2 to the axial pressure connection P and has a valve bore 12 designed as a blind hole, which ends at an axial distance from the left end face of the valve housing 6 in FIG. The right end portion of the valve bore 12 in FIG. 2 is expanded to a receptacle 14 into which the housing of an electromagnet 16 is screwed. It is a commercially available switching magnet, so that a further description can be dispensed with. A guide plate 18 is pressed against the end face of the receptacle 14 via the housing of the electromagnet 16. This guide plate 18 has a radially tapered part of the valve bore 12 opening through bore which is provided with a conical abutment shoulder 22.

At this contact shoulder 22, the illustrated rest position of the seat valve, a spherical valve body 24 can be supported. The through hole 20 is further penetrated by the end portion of a plunger 26 which bears against the valve body 24.

The guide plate 18 furthermore has one or more openings 28 which are offset radially to the through bore 20 and which on the one hand open into a space 30 delimited by the housing of the electromagnet 16 and on the other hand into a pressure space 32 which bears from end-face bores in the annular end face of the receptacle 14 and of the same adjacent end face of the guide plate 18 is limited. Pressure chamber 32 and chamber 30 are thus hydraulically connected to one another.

In the opening in the pressure chamber 32 part of the valve bore 12, a seat bushing 34 is inserted, which dips into the pressure chamber 32 with an end face. On this end face, a valve seat 36 for the valve body 24 is formed. The seat bushing 34 is penetrated by a transmission element 38 which is guided with a radially expanded part in the inner bore of the seat bushing 34. Longitudinal channels 40 are formed on this radially widened part, which allow the seat bushing 34 to flow through. The radially tapered part of the transmission element 38 limits, together with the adjacent U beginning portion of the valve bore 12, a seat space 42 in which one or more oblique bores 44 open, via which the tank or working connection of the valve housing is formed. This oblique bore 44 connects the seat 42 with the tank channel 10. The radially tapered part of the transmission element 38 bears against a sliding body 46 which is guided axially displaceably in the left end portion (FIG. 2) of the valve bore 12. On the outer periphery of the sliding body 46, a seal 48 is arranged, via which the Seat space 42 is sealed from a spring space 50 for a compression spring 52. This spring chamber 50 is limited by the sliding body 46 and the end portion of the valve bore 12.

The valve body 24 is thus lifted from its valve seat 36 by the compression spring 52 supported on the end face of the valve bore 42, the sliding body 46 and the transmission element 38 resting thereon. The valve housing 6 is further penetrated by a connecting channel 54 which opens on the one hand in the pressure connection side end face and on the other hand in the pressure chamber 32. This longitudinal channel 54 is formed by an angular bore, which consists of an axially spaced from the valve axis bore portion 55 and an obliquely positioned bore 56. The latter cuts a corner area of the spring chamber 50 so that it is hydraulically connected to the pressure port P. The other end section of the connecting channel 54 ends in the pressure chamber 32. The pressure medium can thus enter the pressure chamber 32 from the pressure port P through the connecting channel 54 and from there passes through the openings 28 into the plunger 26 through the space 30 of the electromagnet 60, so that the valve axis is pressure balanced. As a result, the actuating forces of the valve body 24 can be minimized.

The embodiment shown in Figure 2 corresponds to the circuit symbol shown in Figure 1 a. That is, in the rest position shown when the electromagnet 16 is de-energized, the pressure connection P is connected via the connecting channel 55, the pressure chamber 32, the valve body 36 lifted off the valve seat 36, the longitudinal channels 40, the seat chamber 42 and the inclined channel 44 to the tank connection T. In other words, the seat valve 1 is in its inoperative position in the rest position, in which pressure medium can flow from the pressure connection P to the other connection (tank connection T or working connection).

When energizing the electromagnet 26, the plunger 26 is in the

2 moves to the left so that the valve body 24 is placed by the force of the electromagnet 16 on its valve seat 36. This creates the connection between the pressure chamber 32 or the space 30 and the tank connection T (working connection) closed, so that the pressure medium cannot flow out of the pressure space 32.

The closing movement of the valve body 34 takes place against the force of the compression spring 52, which is in operative connection with the valve body 24 via the sliding body 46 and the transmission element 38.

The configuration of the connecting channel 54 according to the invention enables it to be introduced simply by drilling from the end faces of the housing 6, it not being necessary to provide a separate channel in order to connect the connecting channel 54 to the spring chamber 50.

Figure 3 shows an embodiment that differs from the above-described embodiment only in the channel guide - the function corresponds to the circuit symbol shown in Figure 1 a. In other words, the seat valve 1 shown in FIG. 3 enables a pressure medium flow from the pressure connection P to the other connection (tank connection T, working connection A) in the rest position; this connection is blocked when the electromagnet is energized by placing the valve body 24 on its valve seat 36. In the following, the same reference numerals are used for corresponding components as in the embodiment shown in Figure 2, so that a repeated description with reference to the above explanations is omitted.

In the embodiment shown in Figure 3, the two connections are interchanged, i.e. the pressure connection P is designed as a radial connection and the tank connection T (working connection A) as an axial connection.

The essential change compared to the above-described embodiment is that the connecting channel 54 is designed as an oblique blind hole extending from the annular end face of the receptacle 14 to the spring chamber 50. The The axis of this oblique bore is chosen so that the spring chamber 50 is cut. In this embodiment, the connecting channel 54 is further not formed by an angle hole but by a single hole. Of course, the angle bore according to FIG. 2 could also be carried out through a single obliquely positioned bore.

The connection with the now radially extending pressure channel 10 takes place via a transverse bore 58 which opens into the connecting channel 54 and is drilled radially into the valve housing 58 from the outer circumference.

The valve housing 6 is further penetrated by a longitudinal bore 60 which cuts into the end face on the one hand in the tank connection side and on the other hand cuts the seat space 42. This longitudinal channel 60 thus corresponds with regard to the function of the oblique bore 44 in FIG. 2. Accordingly, the pressure medium in the rest position of the electromagnet 16 is introduced via the transverse channel 58 and the connecting channel 54 into the spring chamber 50 and the pressure chamber 32, so that the same pressure conditions as in prevailing embodiment prevail. When the valve body 24 is lifted off, the pressure medium can then flow out via the longitudinal channels 40, the seat space 42 and the longitudinal bore 60 to the tank connection T. When actuating the electromagnet 60, the valve body 24 is placed on the valve seat 36, so that the connection between the radial pressure connection P and the tank connection T is blocked.

FIG. 4 shows an embodiment to which the circuit symbol according to FIG. 1b is assigned. That is, the seat valve 1 shown in Figure 4 shuts off the connection between the pressure port P and the tank port T (working port A) in its spring-biased rest position. This connection is opened when the electromagnet 16 is energized.

The channel guide and the basic structure of the valve housing 6 of the embodiment shown in Figure 4 corresponds to that of the seat valve 1 shown in Figure 2, so that explanations in this regard are unnecessary. The changed version is essentially achieved in that the installation position of the valve body 24 and the transmission element 38 is changed to each other. According to FIG. 4, the valve body 24 is arranged between the seat bushing 34 inserted into the valve bore 12 and the sliding body 46, so that the valve seat 36 is formed on the left end face of the seat bushing 34 in FIG. 4. The transmission element 38 is installed offset by 180 °, so that the radially tapered part on the tappet 26 and the other end portion on the valve body 24 abut.

Since in this embodiment the axial displacement of the valve body 24 is limited on the one hand by the seat bushing 34 and on the other hand by the sliding body 46, the guide plate 18 according to FIG. 2 can be dispensed with.

Since the valve seat 36 is now formed on the end face of the seat bushing 34 on the compression spring side, the valve body 24 is biased against its valve seat 36 by the force of the compression spring 52 and the pressure in the spring chamber 50 via the sliding body 46. The pressure in the spring chamber 50 corresponds approximately to the pressure at the pressure port P, which is fed into the spring chamber 50 via the connecting channel 54. This prevents the pressure medium from flowing out of the space 30/32 to the tank connection T or to the working connection A. When current flows through the electromagnet 16, the valve body 24 is lifted via the tappet 26 and the intermediate transmission element 38 from the valve seat 36, so that the pressure medium can flow out of the space 30 via the oblique bore 44 to the radial tank connection T.

In the event that the second connection of the seat valve 1 is designed as a working connection A, a check valve should be designed in the area of the pressure connection P, which prevents a backflow of pressure medium.

As is further indicated by dashed lines in FIG. 4, the geometries of the connecting channel 54 and the spring chamber 50 can be changed. beted, the diameter of these two spaces must always be chosen so that a cut is made by drilling a hole.

Figure 5 shows an embodiment in which the pressure port P and the tank port T are interchanged. The relative arrangement of the movable components corresponds to that in FIG. 4, while the channel guide with the connecting channel 54 designed as a blind hole corresponds to the transverse channel 58 and the longitudinal bore 60 corresponds to the exemplary embodiment according to FIG. 3. The seat valve 1 according to FIG. 5 is also assigned the switching symbol according to FIG. 1 b.

Exemplary embodiments are described below in which the seat valve 1 is designed as a 3/2-way seat valve.

FIG. 6 shows an exemplary embodiment to which the circuit symbol according to FIG. 1 c can be assigned. The seat valve 1 shown has an axial pressure port P and two radial ports A, T, which open into a radial working channel 64 and the tank channel 10 of the valve block.

As in the exemplary embodiments described above, the electromagnet 16 is screwed into the radially enlarged receptacle 14 and, with its fastening section, delimits the rear space 30 in which the valve bore 12 opens. The latter is in turn designed as a blind hole and has a radial recess 66 at a distance from the ring end face of the receptacle 14, through which a space is formed which corresponds to the seat space 42 according to FIG. 2. This reference number is therefore retained in the following for the space formed by the radial recess 66.

In the two sections of the valve bore 12 adjoining the radial egg 66, two axially spaced-apart seat bushings 34, 35 are inserted, via which a valve seat 36 or 37 is formed for the valve body 24 arranged therebetween. Both seated Bushings 34, 35 are each penetrated by a transmission element 38, 39, the radially tapered end sections each being arranged pointing away from the valve body 24.

The valve bore 12 has a section following the left-hand seat bushing 35 in FIG. 6, which ends in a relief chamber 68 which is connected to the tank channel 10 via at least one radially extending tank bore of the valve housing 6.

The radially recessed end section of the transmission element 39, which is supported on the adjacent end face of the sliding body 46, plunges into this relief space 68. This is biased by the compression spring 52 towards the valve body 24. The valve housing 6 is penetrated, similarly to the exemplary embodiment shown in FIG. 2, by a connecting channel 54 designed as an angular bore, which cuts the spring chamber 50 and ends in the axial pressure channel on the one hand and in the chamber 30 on the other hand. The radially tapered end section of the transmission element 38 bears against the plunger 26 of the electromagnet 16.

As can also be seen in FIG. 6, the seat space 42 formed by the radial stitch 66 is connected to the working channel 64 via an inclined channel 72 and a radial bore 74 opening therein. In the illustrated embodiment, the inclined channel 62 is drilled from the pressure connection side end face into the valve housing 6 and closed on one side by means of a sealing plug 76.

In the rest position shown, the pressure medium is fed into the space 30 from the pressure connection P via the connecting channel 54. This pressure is also effective in the spring chamber 50, so that the valve axis is pressure balanced. Since the valve body 24 is seated on the valve seat 36, the pressure medium cannot flow out of the pressure chamber 30 into the seat chamber 42 via the longitudinal channels 40 of the transmission element 38. The pressure medium can from the working connection A via the radial bore 74, the longitudinal channel 72, the seat 42, the Valve seat 37 lifted valve body 24, the longitudinal channels 40 of the connecting element 39, the relief chamber 68 and the tank bore 70 flow out to the tank T so that the pressure at the working connection A is reduced.

That is, in the spring-biased rest position, the pressure port P is shut off, while the working port A is connected to the tank port T. When the electromagnet is energized, the valve body 24 is lifted off its valve seat 36 and rests on the other valve seat 37. As a result, the hydraulic connection between the space 30 and the seat space 42 is opened, so that pressure medium with the pressure at the pressure port P can flow from the pressure space 30 via the longitudinal channels 40 of the transmission element 38 into the seat space 42. An outflow of the pressure medium to the relief chamber 68 is prevented since the valve body 24 is seated on the valve seat 37.

The pressure medium is in this switching position from the seat 42 through the inclined channel 72 and the radial bore 74 to the working connection A, so that the consumer connected to it is supplied with pressure medium. In other words, when the electromagnet 16 is energized, the pressure connection P is connected to the working connection, while the tank connection T is shut off.

Figure 7 shows an embodiment in which the pressure connection P and the working connection A are interchanged, ie the pressure connection P is designed as a radial connection, while the working connection A is an axial connection. Similar to the exemplary embodiment shown in FIG. 3, this is achieved in that the connecting channel 54 is closed off from the axial connection. In the embodiment shown in Figure 3, a blind hole was formed, in the embodiment shown in Figure 7, a through hole is made, which is closed by a plug 76 on the end. The connection to the radial pressure connection P in turn takes place via the transverse channel 58 which penetrates the valve housing wall in the radial direction. The axia le working connection A is connected via an oblique longitudinal bore 60 to the seat space 42, so that the working connection A depending on the actuation of the electromagnet 16 either with the space 30 and thus with the pressure at the pressure connection P or with the relief space 68 and thus with the tank T is connectable. The circuit symbol according to FIG. 1 c is also assigned to this exemplary embodiment.

Figures 8 and 9 relate to two embodiments by which the 3/2-way seat valve according to Figure 1 d is realized.

The structure of the valve housing corresponds in turn essentially to that of the above-described exemplary embodiments according to FIG. 6 or FIG. 7, so that only the distinguishing features are discussed below.

In the exemplary embodiments shown in FIGS. 8 and 9, the pressure connection P with the electromagnet 16 de-energized is connected to the

Working port A connected while the tank port is shut off. When the electromagnet 16 is energized, the working connection A is connected to the tank connection and the pressure connection P is shut off.

In contrast to the exemplary embodiments described with reference to FIGS. 6 and 7, only a single seat bushing 34 is inserted into the valve housing 6, on the end faces of which one of the valve seats 36, 37 is formed. These are each associated with a valve body 24, 25 which can be placed alternately on the associated valve seat 36 or 37. Between the two valve bodies 24, 25 extends a coupling piece 78, which is either designed with a smaller diameter than the inner bore of the seat bush 34 or carries longitudinal grooves on its outer circumference, which enables a pressure medium flow between the valve seats.

The end faces 82 of the coupling piece 78 are crowned with the radius of curvature of the valve body 24, 25, so that the coupling piece is centered with respect to the seat bush 34. Radial openings 80 pass through the center of the seat bushing 34, via which the space formed between the coupling piece 78 and the inner circumferential wall of the seat bushing 34 is connected to the seat space 42.

The valve body 25 is located according to Figure 8 in the region of the relief chamber 68 and is biased against the valve seat 37 via the sliding body 46 and the compression spring 52. The other valve body 24 is axially displaceably guided in the guide plate 18, the structure of which is identical to that of the guide plate according to FIG. 2. That is, the valve body 24 is lifted by the force of the compression spring 52 from its valve seat 36 and biased against the plunger 26 or held in abutment on the abutment shoulder 22. The other structure corresponds to that of the exemplary embodiment shown in FIG. 6.

When the electromagnet is de-energized, the pressure medium from the pressure connection P via the connecting channel 54, the pressure chamber 32 formed between the guide plate 18 and the valve housing 6, the valve body 24 lifted off the valve seat 36, along the coupling piece 78, and via the radial openings 80, the seat space 42 , the inclined channel 72 and the radial bore 74 flow to the working port A. Approximately the same pressure acts in the spring chamber 50 and in the chamber 30. The connection of the seat space 42 to the relief space 68 is blocked by the valve body 25 seated on its valve seat 37.

When the electromagnet 16 is energized, the valve body 24 is moved to the left in the illustration according to FIG. 8, so that it is seated on its valve seat 36, while the valve body 25 is lifted off the valve seat 37.

As a result, the connection between the pressure port P and the working port A is shut off, while the connection between the seat space 42 and the tank port T is opened, so that the

Pressure medium from the working connection A via the radial bore 74, the Inclined channel 72, the seat 42, the radial openings 80, the flow channel between the coupling piece 78 and the seat bush 34, the relief chamber 68 and the tank bore 70 to the tank port T can flow out. The valve body 24 is additionally acted upon by the pressure in the pressure chamber 30 with a pressure force resulting direction on the valve seat 36, so that a tight system is ensured.

In the exemplary embodiment shown in FIG. 9, the pressure connection P and the working connection A are in turn interchanged, the channel guide with the connecting channel 54, the transverse channel 58 and the longitudinal bore 60, which is closed by a plug 76, corresponding to the exemplary embodiment according to FIG. 7, while the seat bushing 34, the coupling piece 78 and the two associated valve bodies 24, 25 are practically identical to the previously described embodiment.

Figure 10 finally shows an embodiment with a changed channel management.

The embodiment shown in Figure 10 is also designed as a 2-ball seat valve and corresponds in principle to the C versions shown in Figures 8 and 9.

The coupling piece 78 of the embodiment shown in Figure 10 is slidably guided in the inner bore of the seat bush 34, that is, the outer diameter of the coupling piece 78 corresponds approximately to the seat diameter of the seat bush 34. At the outer diameter of the coupling piece 78 flats 84 or channels are formed, which together with the inner circumferential wall of the seat bush 34 form longitudinal channels for pressure medium guidance.

The central region of the coupling piece 78 is provided with a double-conical constriction 86 which surrounds the mouth region of the radial openings 80. In this area of the mouth is in the

Inner bore of the seat bushing 34 has a flat annular groove 88, which, together with the constriction 86, delimits a distributor space 90 in which the longitudinal channels formed by the flats 84 open, via which the pressure medium is guided to the respective valve seat 36 or 37.

In the exemplary embodiment shown in FIG. 10, the oblique channel 72 is designed as a through hole which extends from the end face on the pressure connection side into the annular end face of the receptacle 14. The aufnahmesei term end of the inclined channel 73 is closed by a plug 10 which is screwed in from the receptacle 14. The connection of the inclined channel 72 with the radial egg stitch 66 takes place via an inclined bore 92, the axis of which is inclined such that it can be drilled into the valve housing from the receptacle.

The valve body 24 is guided via an insert 94 which is inserted into the housing of the electromagnet 16. This insert 94 is penetrated by the plunger 26 and is expanded in the mouth area, so that a guide for the valve body 24 is created. By eliminating the guide plate 18, the space 30 and the pressure space 32 coincide in the embodiment shown in FIG.

In the embodiment shown in Figure 10, the channel management is again significantly simplified compared to the above-described embodiments, so that the manufacturing costs can be further reduced. Furthermore, the pressure losses when the pressure medium flows back from the consumer to the tank are reduced by the formation of the distributor space 90.

With regard to the function of the valve shown in FIG. 10, reference is made to the comments on the exemplary embodiment according to FIG. 8.

What is disclosed is a directly actuated seat valve with a pressure-balanced valve axis, in which the spring chamber for at least one Valve body is connected to the pressure connection via a connecting channel which is so inclined to the valve axis that it cuts the spring chamber. With this design, it is not necessary to provide radially extending channels for the hydraulic connection of the spring chamber, so that the manufacturing outlay is reduced compared to conventional solutions.

Claims

Expectations

1. Seat valve with at least one valve body (24) guided in a valve bore (12), to which at least one valve seat (36, 37) is assigned, and via which a pressure connection (P) with at least one working or tank connection ( A, T) can be connected, the valve body (24, 25) being biased directly or indirectly via a compression spring (52) in the direction of the valve seat (36, 37) and acted upon in the opposite direction by an electromagnet (16), whereby in the spring chamber (50) there is approximately the same pressure as on an end face of the valve body (24, 25) on the valve seat side, so that the valve axis is pressure balanced, characterized in that in the valve housing (6) an at least partially oblique to the valve axis extending connecting channel (54) is formed which on the one hand cuts the spring chamber (50) and on the other hand opens into a pressure chamber (30, 32) adjoining the end section of the valve body on the valve seat side (24, 25) ,

2. Seat valve according to claim 1, characterized in that the valve housing (6) is cartridge-shaped and the pressure connection (P) is an axial connection, and that the connecting channel (54) from the pressure connection-side end face of the valve housing (6) to Pressure chamber (30, 32) extends, the other connection (A, T) being designed as a radial connection, and via a channel (44, 72) with a seat space (42) adjacent to the valve seat (36, 37) between the rear side Pressure chamber (30, 32) and the spring chamber (50) is connected.

3. Seat valve according to claim 1, characterized in that the valve housing (6) is cartridge-shaped and the pressure connection (P) is a radial connection which is connected via a transverse channel (58) to the connecting channel (54) which in the region of Spring chamber (50) ends, the other connection (A, T) being designed as an axial connection, which adjoins the valve seat (36, 37) via a longitudinal bore (60). zenden seat (42) between the rear pressure chamber (32) and the spring chamber (50) is connected.

4. Seat valve according to claim 2 or 3, characterized gekennzeich- net that the connecting channel (54), the channel (44, 72) and / or the longitudinal bore (60) through the housing in the longitudinal direction penetrating bore sections are formed, which may be one-sided are closed by a plug 76.

5. Seat valve according to one of the preceding claims, characterized in that in the region between the compression spring (52) and valve body (25) at least one sliding body (46) is arranged, which is sealingly guided in the valve bore (12), and that Valve seat (36, 37) is formed on a seat bushing (34, 35) inserted into the valve bore (12).

6. Seat valve according to claim 5 and claim 2 or 3, characterized in that the valve body (24) is associated with a further valve seat (37) so that the valve body (24) by the action of the compression spring (52) and the electromagnet (16) can be alternately pretensioned against one of the valve seats (36, 37), the seat space (42) being arranged between the two valve seats (36, 37).

7. Seat valve according to claim 6, characterized in that the valve seats (36, 37) on facing end faces of two in the valve bore (12) inserted seat bushings (34, 35) or on the two end faces of a single valve bushing (34) are.

8. Seat valve according to claim 7 second alternative, characterized in that between the two valve bodies (24, 25) a seat bushing (34) penetrating coupling piece (78) is arranged, which is designed such that pressure medium between see the valve seats (36, 37) and the seat space (42) can flow through a radial recess (66) in the valve housing (12) is formed, open into the radial openings (80) of the seat bushing (34).

9. Seat valve according to claim 8, characterized in that the coupling piece (68) flats (86) or longitudinal channels

Pressure medium management.

10. Seat valve according to one of the claims 1 to 9, characterized in that between a valve body (24) and a plunger in the rear pressure chamber (30, 32) plunger (26) of the electromagnet (16), a transmission element (38) is arranged which passes through the seat bushing (34) and is provided with longitudinal channels (40) so that pressure medium can flow from the pressure chamber (30, 32) to the valve seat (36).

11. Seat valve according to one of the claims 5 to 10, characterized in that the valve is designed as a 3/2-way valve, the pressure or the working connection (P, A), as an axial connection and a tank connection (T) and the each other connection (A, P) are designed as a radial connection and the tank connection (T) via a tank bore (70) opens into a relief chamber (68) adjacent to one of the valve seats (36, 37), into which the spring chamber (50 ) immersed sealing slide body (46).

12. Seat valve according to one of the preceding claims, characterized in that the valve is designed as a 2/2-way valve, one connection (P; A, T) as a radial connection and the other connection (A, T; P) as an axial are trained.