WO2010020241A1

WO2010020241A1 - Valve arrangement

Info

Publication number: WO2010020241A1
Application number: PCT/DE2009/001184
Authority: WO
Inventors: Michael Dürr; Michael Gaumnitz; Bernd Schröder; Jörg Weingart
Original assignee: Robert Bosch Gmbh
Priority date: 2008-08-19
Filing date: 2009-08-18
Publication date: 2010-02-25
Also published as: DE102008038338A1

Abstract

The invention relates to a valve-controlled hydraulic engine and a valve arrangement comprising a closing body (50) for closing a through-opening (43) for a pressure medium, the closing body being adjustable by a first adjusting mechanism such that the closing body performs an opening stroke or a closing stroke. The closing body is adjusted by a second adjusting mechanism such that it performs an additional stroke, the entire stroke of the closing body being longer or shorter than the stroke caused by the first adjusting mechanism on its own.

Description

description

The invention relates to a valve arrangement according to the preamble of

Claim 1 and a valve-controlled hydraulic machine with such a valve arrangement.

Valve-controlled hydraulic machines and valve arrangements are known, for example, from EP 1 537 333 B1. This document shows a hydraulic machine in axial or radial piston construction, which can be operated in principle as a motor or as a pump, wherein the delivery or absorption volume via the valve control is infinitely adjustable. In one described embodiment, the hydraulic machine is designed as an axial piston machine, wherein a plurality of piston arranged in a cylinder is supported on a rotatably mounted swash plate. Each piston defines with the associated cylinder chamber a working space which can be connected via an inlet valve and a drain valve with a pressure medium inlet or a pressure medium drain.

In the known solution, the two valves are designed as electrically unlockable or lockable check valves, which are controlled by the pump control and to operate the respective working space in "fill mode", in "partial mode" or in "idle mode". fill mode ", essentially the entire displacement or displacement volume is utilized, in" partial mode "only a part of the volume is used, while in" idle mode "the delivery / displacement volume of the respective working space is 0 - the machine is idling.

Via a control unit, the hydraulic machine is operated according to a control algorithm in order to achieve the lowest possible pulsation sum flow volume (pump) or total displacement volume flow (motor). The volume flow adjustment is often carried out according to a phase control, but it can also be performed after a Phasenabschnitts- or phase cut control. In the described solution, the supply valve arranged in the inlet to each working space is closed in the de-energized state by means of spring force. The check valve arranged in the outlet is biased in the de-energized state by the spring force in the opening direction.

If the hydraulic machine is to be operated as a motor, the drain valve is closed by energizing an actuating magnet for driving a shaft connected to the swash plate and simultaneously opens the inlet valve. As a result, pressure medium can flow into the working space, so that the hydraulic energy of the pressure medium is converted by the axial displacement of the respective piston and the corresponding rotational movement of the swash plate into a rotational movement of the shaft and thus into mechanical energy. Shortly before the inner dead center, in which the respective piston has carried out the full swallowing movement, the inlet valve is closed, so that is relieved of pressure by the remaining residual stroke of the piston to the dead center of the working space. Through this pressure relief, the drain valve can open pressure relieved and the piston can push out in his subsequent conveying movement his swallow volume to the tank. Shortly before the outer dead center then the drain valve is closed by energizing the corresponding actuating magnet. The remaining stroke of the piston to outer dead center is then used to compress the trapped in the working space

Used pressure medium, so that the inlet valve can open when pressure reaches the outer dead center. This process ensures that the check valves can be switched in the largely pressure-balanced state by relatively low actuating magnetic forces. This control is necessary due to the required switching dynamics.

A prerequisite for this type of control (DDP principle (digital displacement pump)) is that the low-pressure and high-pressure side valves can be switched with high dynamics, so that the above-described pressure fluid flow paths can be shut off very quickly or released to flow through.

In the US 7,077,378 B2 a valve assembly for such a hydraulic machine is shown, in which an annular flow opening through a cup-shaped Valve element can be closed. This annular flow opening is bounded by an inner and an outer sealing seat, so that the specific surface pressure at the sealing edge with respect to a valve cone is comparatively low. A disadvantage of this known solution is that due to the complex structure of the cup-shaped valve element and its guide and the valve housing designed with an annular flow opening of the device-technical complexity for the realization of the valve assembly is considerable.

Another disadvantage of the known solution is that the flow resistance when flowing through the annular flow opening and the flow around the cup-shaped valve element is comparatively high, so that the efficiency of the hydraulic machine is comparatively low.

In contrast, the invention has for its object to provide a valve assembly and a valve-controlled hydraulic machine, in which the control modes described above with low device complexity and high dynamics can be realized.

This object is achieved by a valve arrangement having the features of patent claim 1 and a valve-controlled hydraulic machine having the features of patent claim 18.

According to the invention, a valve arrangement has a closing body for closing a pressure medium passage opening. The closing body is in this case adjustable via a first adjusting mechanism, so that the closing body performs an opening or closing stroke. A second adjusting mechanism of the closing body is adjustable so that it performs an additional stroke, whereby a total stroke of the closing body is greater or smaller than the stroke caused solely by the first adjustment.

This solution has the advantage that the pressure medium passage opening is widened by the additional stroke and thus flow resistance in the Flow through the Druckmitteldurchgangsöffnung be reduced. Furthermore, an extremely simple construction of the valve arrangement is made possible.

In one variant, the additional stroke of the closing body which is opened via the first adjusting mechanism can be effected by flow forces acting in the opening direction on the closing body.

In an advantageous embodiment of the invention, the closing body is acted upon by the first adjusting mechanism in the opening direction by a first spring and in the closing direction by a magnetic force of a lifting magnet.

The closing body can be acted upon by the second adjusting mechanism in the closing direction of a second spring.

The closing body is, for example, fixed to a guided from a valve housing and axially slidably mounted therein guide ram.

In a further embodiment of the invention, the guide tappet is received in an axially displaceable valve sleeve slidably mounted on the valve housing. The valve sleeve can be used to adjust the closing body over the first

Adjusting mechanism with a closing body facing end face on the closing body and be supported with a deflecting from the closing body end face via a second spring on a support plate connected to the support plate.

Appropriately, a slidable by the solenoid and is arranged approximately in a hollow cylindrical armature on a Schließkörperfemen Hülsenendbereich the valve sleeve, which firmly surrounds the valve sleeve with a first longitudinal section and receives the second spring and the support plate of the guide plunger with a second longitudinal section.

Advantageously, the first spring is supported on the valve housing and biases the closing body in the opening direction via the magnet armature and the valve sleeve. The second spring is preferably associated with the second adjusting mechanism and biases the closing body over the bearing plate and the guide plunger in the closing direction.

The opening stroke of the first adjusting mechanism is limited, for example, by a stop ring formed on a sleeve lateral surface of the valve sleeve, wherein the stop ring can be abutted against a housing stop arranged on the valve housing.

In a further preferred embodiment of the invention, the first spring is supported on the valve housing and biases over a first end face of an approximately hollow cylindrical and sealed on both sides magnet armature, wherein the guide armature is guided approximately axially by the magnet armature and a third spring on a second end face of the magnet armature is supported and biases an axially displaceable on the guide plunger and engageable on a housing stop stop ring, which is displaceable over a driving projection on the guide plunger in a closing stroke away from the housing stop. This solution allows an extremely compact and simply constructed valve arrangement.

Advantageously, the second spring in the magnet armature is supported on a first inner surface facing in the same direction as the first end face and biases a support plate arranged in the magnet armature and firmly connected to the guide tappet, wherein the support disk is engaged in a non-executed additional stroke of the second adjustment mechanism is supported on a second inner surface of the magnet armature opposite the first inner surface.

In a simple embodiment, the closing body is displaceably guided axially on an end section, guided from a valve housing, of a guide plunger axially displaceably mounted in the valve housing. The end portion of the guide plunger can be radially stepped back in the guide region of the closing body, whereby two annular surfaces are formed. It may be expedient if the closing body strikes against a stop surface on the first annular surface, which deflects the valve housing, and is biased by the second spring, which is supported on the second annular surface and the closing body via one of the stop surface when the second adjusting mechanism is not executed biases repellent support surface.

In a further embodiment of the embodiment, the first spring is supported on the valve housing and biases a fixedly connected to the guide plunger armature in front in the opening direction, wherein a fixedly connected to the guide plunger stopper ring rests against a housing stop.

Advantageously, a valve-controlled hydraulic machine has a valve arrangement in which the second spring is arranged in a closable by the Schließköφer delivery chamber of the hydraulic machine and is supported on a support means formed in the pumping support and biases the closing body.

Preferably, a valve-controlled hydraulic machine has a valve arrangement as explained above.

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

In the following preferred embodiments of the invention will be explained in more detail with reference to schematic drawings. Show it:

Figure 1 is a highly schematic representation for explaining the principle of operation of a valve-controlled hydraulic machine with variable displacement / delivery volume;

2a shows a first embodiment of an electrically actuated check valve of a hydraulic machine according to Figure 1 in the open position; Figure 2b, the check valve of Figure 2a in the open position with an additional stroke;

Figure 2c, the check valve of Figure 2a and 2b in the closed position;

3a shows a second embodiment of an electrically operated check valve of a hydraulic machine according to Figure 1 in the open position;

Figure 3b, the check valve of Figure 3a in the open position with an additional stroke;

Figure 3c, the check valve of Figure 3a and 3b in the closed position;

Figure 4 shows a third embodiment of a check valve in the closed position; and

Figure 5 shows a fourth embodiment of a check valve in the closed position.

The functional principle of a valve-controlled hydraulic machine 1 whose delivery / displacement volume is digitally adjustable (DDP) will first be explained below with reference to FIG. The hydraulic machine 1 described is designed as a swash plate type axial piston machine, wherein FIG. 1 shows a very simplified development of such a hydraulic machine 1 in an axial piston construction. In the following, only the components essential for understanding the invention will be explained. For more detailed information, reference is made to the above-mentioned prior art. In the following description, the hydraulic machine 1 according to the invention is designed as a hydraulic motor, in principle, however, the statements on the hydraulic motor also apply correspondingly to a pump with an adjustable delivery volume.

According to the schematic representation in FIG. 1, the hydraulic machine 1 has a cylinder 2, in which a multiplicity of cylinder bores 4 are formed, in each of which a piston 6 is guided in an axially displaceable manner. Each of the piston 6 limited with the Cylinder bore 4 a working space 8, whose volume is dependent on the stroke of the piston 6. The pistons 6 are supported via a respective piston shoe 10 on an inclined swash plate, which is connected to an output shaft 12. In the illustration according to FIG. 1, the control curve 14 formed on account of the rotation of the swash plate is shown, which reproduces the rotational angle dependence of the piston stroke and thus of the volume of the respective working space. As shown on the right in FIG. 1, each working space 8 is connected via an inlet valve 16 to a supply line 18 which is common to all work spaces 8 and which is supplied with a system or high pressure. This high pressure can be generated for example via a pump 20.

Each working space 8 is further connected via a drain valve 22 with a likewise all working spaces 8 common drain line 24, which opens into a tank 26.

As already explained at the outset, the drain valves 22 and the inlet valves 16 are each designed as electrically releasable or lockable non-return valves. The inlet valve 16 is biased by a spring, not shown, in its illustrated basic position in a closed position and can bring by energizing an actuating magnet 28 in an open position, so that the

Pressure medium from the supply line 18 can flow into the respective working space 8. The drain valve 22 is biased in its illustrated basic position via a spring in an open position. By energizing an actuating magnet 30, this drain valve 22 can be brought into a blocking position in which the pressure medium can not flow out of the working space 8.

The control of the actuating magnet 28, 30 via a control unit 34, via which the modes described above (fill mode, partial mode and idle mode) are adjustable, so that the displacement of the hydraulic machine 1 is infinitely adjustable, with suitable control of the valves 16 , 22 also the pulsation can be lowered to a minimum. In the illustrated Ausführungsbeispie ⁾ , the control of the valves 16, 22 in response to the rotational speed of the output shaft 12, which is detected by a Drehzahlaufnehmer 36 and via a Signal line is reported to the control unit 34. In principle, other characteristic data, such as, for example, the torque acting on the output shaft 12 or the displacement of the hydraulic machine 1 in the control of the valves 16, 22, can of course also be taken into account.

Figure 2a shows the basic structure of a check valve according to a first embodiment, which corresponds to the drain valve in the hydraulic motor according to FIG. In a hydraulic pump, the valve 22 is the inlet or suction valve 22, which is assumed in the following figure descriptions.

The suction valve 22 has a valve element 40, which is biased by an initial spring 38 into an open position and which can be moved in the closed position against a valve seat 42 by means of an actuating magnet 30, so that an annular pressure medium passage opening or flow cross section 43 is shut off (see FIG. 2c). The spring 38 is supported on a housing inner surface 44 of a valve housing 46.

The suction valve 22 is designed as a so-called "poppet valve", wherein the valve element 40 has an axial guide tappet 48 passing through the valve seat 42 and a closing body 50 attached thereto

Running truncated cone, wherein on the lateral conical surfaces a circumferential, obliquely adjusted sealing surface 52 is formed. The valve seat 42 is shaped accordingly, so that a tight contact in the closed state (Figure 2c) is ensured. The Fühmngsstößel 48 is further accommodated axially slidably in an approximately hollow cylindrical valve sleeve 54. This is also axially slidably mounted in the valve housing 46 and is located with a first closing body 50 facing end face 56 on the closing body 50 in approximately. On a side facing away from the closing body 50 second end face 58 of the valve sleeve 54, a second spring 60 is supported, wherein the second spring 60 acts on a support plate 62 with spring force, which is formed on the closing body 50 opposite end portion of the guide tappet 48, whereby the closing body 50 via the guide tappet 48 and the support plate 62 is biased against the second end face 56 of the valve sleeve 54. The valve sleeve 54 is in the illustrated embodiment of a hollow cylindrical Armature 64 firmly embraced, which is acted upon by the spring force of the second spring 38 in the direction of the opening position shown in Figure 2a. The magnet armature 64 encloses the valve sleeve 54 with a first longitudinal section and receives the second spring 60 and the support plate 62 of the guide tappet 48 with a second longitudinal section. The armature 64 is partially of a

Magnetic coil 66 of an actuating magnet or solenoid embraced, which is accommodated in the valve housing 46.

Adjacent to the armature 64, a stop ring or a pole ring 68 of magnetizable material is attached to the valve sleeve 54. This sits in the spring-biased home position on a housing stop or permanent magnet 70, so that the valve sleeve 54 and with this the valve member 40 is held by the force of the permanent magnet 70 and the bias of the first spring 38 in the open position. Pressure medium can thus flow through the annular flow cross-section 43 in the working space 8 of Figure 1.

FIG. 2b shows the suction valve 22 in a position in which the closing body 50 carries out an additional stroke, which is explained in more detail below. As a result of a suction process of the hydraulic pump pressure fluid flows through the

Flow cross-section 43, wherein flow forces acting on the closing body 50 in the opening direction. If the flow forces acting on the closing body 50 exceed the spring force of the second spring 60, then this is tensioned via the support plate 62, the guide tappet 48 and the closing body 50, and the closing body 50 carries out an additional stroke h. By this additional stroke h is the

Throughflow cross section 43 increases, wherein the flow resistance decreases and the working or delivery chamber 8 of Figure 1 is filled as best as possible during the suction phase of the hydraulic pump. If the flow forces acting on the closing body 50 are less than the spring force of the second spring 60, the closing body 50 is displaced in the closing direction via the guide tappet 48 and the support plate 62 by the second spring 60 until the closing body 50 contacts the first end face 56 of the valve sleeve 54 is present. As shown in Figure 2c is for closing the

Flowed through the cross-section 43, the magnetic coil 66 and the magnet armature 64 moves upward in Figure 2c, wherein the magnetic flux from the magnetic coil 66 via the adjacent housing walls, through the pole ring 68 through the valve sleeve 54 and the armature 64 and then again over the adjacent housing walls back to the solenoid 66 is done. In this case, the magnet armature 64 is displaced against the spring force of the first spring 38 and against the force of the permanent magnet 70 until the obliquely employed sealing surface 52 of the closing body 50 is in sealing contact with the valve seat 42, so that the annular flow cross-section 43 is shut off.

The spring force of the second spring 60 of Figures 2a - c is determined primarily by two opposing targets. On the one hand, the spring force should be as low as possible and, for example, smaller than an opening pressure of 0.3 bar acting on the closing body 50 by the pressure fluid flow, so that the throughflow cross section 43 is further opened by the additional stroke h at low flow forces during the suction phase, so that the delivery chamber 8 the hydraulic pump 1 of Figure 1 is best and quickly filled during the suction phase. On the other hand, the spring force of the second spring 60 should be as large as possible, so that the closing body 50 closes quickly in the region of the bottom dead center of the piston 6 of Figure 1 in order to minimize Rückströmverluste. Depending on the size and speed of the hydraulic pump 1 from FIG. 1, typical spring forces of the second spring 60 or opening pressures correspond to an opening pressure of between 0.3 and 1 bar.

By the suction valve 22 of Figures 2a - c is the required stroke of the

Magnetankers 64 for closing the flow cross-section 43 on the closing body 50 significantly reduced, since the additional stroke is made on the spring force of the second spring 60. As a result, smaller magnetic currents and a lower magnetic force for closing the suction valve 22 are thus necessary.

The first spring 38 and the armature 64 thereby form a first adjusting mechanism and the second spring 60 and the flow forces in Figure 2b of the pressure medium, a second adjusting mechanism. By the additional stroke h in Figure 2b, for example, a bypass valve to increase a flow cross-section is no longer necessary.

FIG. 3 a shows a second exemplary embodiment of the suction valve 22 which, as an essential difference from FIG. 2 a, has no valve sleeve 54. The armature 64 is designed substantially hollow cylindrical and closed, wherein the guide tappet 48 is passed through this axially displaceable. The magnet armature 64 is thereby held in an open position of the suction valve 22 via the first spring 38, which acts on its first end face 72 facing away from the closing body 50 and via a third spring 74, which acts on its second end face 76, wherein the first Spring 38 on the valve housing 46 and the third spring 74 on the axially displaceably mounted on the guide tappet 48 pole ring 68 is supported. The magnet armature 64 further has two inner surfaces 78, 80, wherein at the first closing surface 50 facing inner surface 78 of the guide tappet 48 connected to the support plate 62 at a non-executed additional stroke h (compare with Figure 3b) is applied, in this position by the second spring 60, which is clamped between this and the second, the closing body 50 facing away from inner surface 80 of the armature 64 is supported.

Figure 3b shows the suction valve 22 according to the second embodiment, in an open position with the additional stroke h. By acting on the closing body 50 flow forces when the flow acting in the opening direction of the flow forces exceed the spring force of the second spring 60, via the closing body 50, the guide tappet 48 and the support plate 62, the second spring 60 is tensioned, whereby an additional stroke h takes place and the flow cross section 43 is opened further. The armature 64 is held by the third spring 74 in an approximately constant position.

Once acting on the closing body 50 in the opening direction

Flow forces decrease and the spring force of the second spring 60 is greater than the flow forces, the support plate 62, the guide tappet 48 and the Closing member 50 is moved in the closing direction until the support plate 62 on the first inner surface 78 of the magnet armature 64 approximately abuts (see Figure 3a).

In FIG. 3c, the magnetic coil 66 according to the first exemplary embodiment in FIG. 2c is energized to close the flow cross-section 43 from FIG. 3b. The magnet armature 64 thereby moves in the closing direction and takes on the second inner surface 80 of the magnet armature 64 supporting second spring 60, the biased about this support plate 62 and thus the guide plunger 48 and the closing body 50 until the closing body 50 with the sealing surface 52nd approximately abuts the valve seat 42. During the movement of the guide tappet 48 in the closing direction, the pole ring 68 is carried along via a driving projection 82 formed on it. The driving projection 82 is in this case open suction valve 22 without additional stroke, see Figure 3a, approximately at the pole ring 68 at.

Figure 4 shows a third embodiment of the suction valve 22 in the closed position, wherein the second adjusting mechanism is arranged with the second spring 60 outside of the valve housing 46. The guide tappet 48 is guided in the valve housing 46 and fixedly connected to the armature 64, wherein the armature 64 is acted upon in the opening direction as in the preceding embodiments with a spring force of the first spring 38. Furthermore, with the guide tappet 48 of the pole ring 68 is firmly connected.

A closing body guide tappet 85, which has a reduced cross section in comparison to the guide tappet 48, is connected to the guide tappet 48 substantially coaxially outside the valve housing 46 and has a support plate 86 at its end region arranged in the working space 8 from FIG.

On the Schließkörperführungsstößel 85 of approximately bell-shaped closing body 50 is guided axially displaceable along its longitudinal axis. The closing body 50 is slightly spaced from an annular surface 90 of the valve housing 46 with an upper end surface 88 at a non-executed additional stroke of the suction valve 22 so that the closing body 50 is not overdetermined and with the sealing surface 52 on the valve seat 42 in the closed state of Drain valve 22 is present. The closing body 50 is biased in the closing direction via the second spring 60, which is stretched between the support plate 86 of the closing body guide tappet 85 and an inner surface 91 of a cup-shaped spring receptacle 92 of the closing body 50 facing the support plate 86.

To open the suction valve 22, the energization of the solenoid 66 is interrupted, wherein the first spring 38 shifts the guide plunger 48 via the armature 64 in the opening direction until the pole ring 68 abuts the permanent magnet 70 in approximately. If the flow forces exceed the spring force of the second spring 60 in the opened state of the suction valve 22, this is stretched over the inner surface 91 of the closing body 50 in the opening direction and the closing body 50 performs an additional stroke.

The embodiment of Figure 4 offers a special advantage. The spring 60 can be designed so that the closing body 50 on the one hand and the

Guide ram 48 and the armature 64 on the other hand are mechanically decoupled and a damping effect is achieved by the spring. As a result, the mechanical load on the guide tappet 48 and the armature 64 when closing the valve can be kept low.

FIG. 5 shows a schematic illustration of a fourth exemplary embodiment of the suction valve 22 in a closed position when the magnet coil 66 is energized. The second spring 60 of the second adjusting mechanism is arranged in the delivery chamber 8 of the hydraulic machine 1 of FIG. 1 and biases the closing body 50 in the direction of the Guide plunger 48 and thus in the closing direction of the suction valve 22, wherein the second spring 60 is supported on a support means 8 formed in the support chamber 92 and the first 50 the guide plunger 48 repellent end face 94 biases the closing body 50. With a second end face 96, the closing body 50 abuts approximately on the guide tappet 48 and the valve seat 42.

In the illustration in Figure 5, the piston 6 is indicated schematically and an open drain valve 98 of the conveyor chamber 8 is shown. A closing body 100 of the Drain valve 98 is biased by a, for example, on a hydraulic machine housing 104 supporting the valve spring 102 in the closing direction.

In a Schluckbewegung of the piston 6 in Figure 5, the drain valve 98 closes with the closing body 100 and the energization of the solenoid 66 of the

Suction valve 22 is interrupted. The first spring 38 relaxes and moves the guide tappet 48, which in turn shifts the closing body 50 over the end edge 96 in the opening direction. The second spring 60 biases the closing body 50 before. If pressure medium flows through a flow cross-section and thereby exceeds the force acting on the closing body 50 and acting in the opening direction flow forces the spring force of the closing body 50 biasing second spring 60, so this opens further to the additional stroke, wherein the second spring 60 is further tensioned.

Disclosed is a ventilgesteurte hydraulic machine and a valve assembly having a closing body for closing a Druckmitteldurchgangsöffnung, wherein the closing body is adjustable via a first adjusting mechanism, so that the closing body performs an opening or closing stroke. A second adjustment mechanism of the closing body is adjusted so that it performs an additional stroke, wherein a total stroke of the closing body is greater or less than the stroke caused solely by the first adjustment.

LIST OF REFERENCES

1 hydraulic machine

2 cylinders

4 cylinder bore

6 pistons

8 workspace

10 piston shoe

12 output shaft

14 control curve

16 inlet valve

18 supply line

20 pump

22 drain valve

24 drain line

26 tank

28 actuating magnet

30 actuating magnet

34 control unit

36 speed sensor

38 spring

40 valve element

42 valve seat

43 flow cross section

44 housing inner surface

46 valve housing

48 guide tappets

50 closing bodies

52 sealing surface

54 valve sleeve

56 face

58 face

60 spring 62 support plates

64 magnet armature

66 solenoid coil

68 pole ring

70 permanent magnet

72 face

74 spring

76 face

78 inner surface

80 inner surface

82 Carriage Projection

85 closing body guide plunger

86 support plates

88 face

90 ring surface

91 inside surface

92 support device

94 face

96 face

98 drain valve

100 closing bodies

102 valve spring

104 hydraulic machine housing h additional stroke

Claims

claims

1. Valve arrangement with a closing body (50) for closing a pressure medium passage opening (43), which via a first

Adjusting mechanism is adjustable, so that the closing body (50) performs an opening or closing stroke, characterized by a second adjusting mechanism over which the closing body (50) is adjustable so that it performs an additional stroke (h), so that a total stroke of the closing body ( 50) larger or smaller than that alone by the first

Adjustment mechanism is effected stroke.

2. Valve arrangement according to claim 1, wherein the additional stroke (h) is effected by acting in the opening direction on the closing body (50) flow forces.

3. Valve arrangement according to claim 1 or 2, wherein the closing body (50) via the first adjusting mechanism in the opening direction of a first spring (38) and in the closing direction of a magnetic force of a solenoid is acted upon.

4. Valve arrangement according to one of claims 1 to 3, wherein the closing body (50) via the second adjusting mechanism in the closing direction of a second spring (60) and in the opening direction of the flow forces can be acted upon.

5. Valve arrangement according to one of the preceding claims, wherein in a valve housing (46) axially displaceably mounted guide tappet (48) with one of the valve housing (46) guided end portion with the closing body (50) is firmly connected.

6. Valve arrangement according to claim 5, wherein the guide tappet (48) in a valve housing (46) axially slidably mounted valve sleeve (54) is accommodated.

7. Valve arrangement according to claim 6, wherein the valve sleeve (54) for adjusting the closing body (50) via the first adjusting mechanism with a closing body (50) facing end face (56) on the closing body (50) and with one of the closing body (50 ) repellent end face (58) via the second spring (60) on a with the guide plunger (48) connected to the support plate (62) is supported.

8. Valve arrangement according to claim 7, wherein at a Schließkörperfemen Hülsenendbereich the valve sleeve (54) displaceable by the lifting magnet and approximately hollow cylindrical armature (64) the valve sleeve (54) with a first longitudinal section firmly engages and with a second longitudinal section, the second spring ( 60) and the support plate (62) of the guide tappet (48) receives.

9. Valve arrangement according to one of claims 8, wherein the first spring (38) on the valve housing (46) is supported and via the armature and the valve sleeve (54) biases the closing body (50) in the opening direction.

10. Valve arrangement according to claim 9, wherein the second spring (60) the second

Assigned adjusting mechanism and biases the closing body (50) via the support plate (62) and the guide plunger (48) in the closing direction.

11. Valve arrangement according to one of claims 6 to 10, wherein the opening stroke of the first adjusting mechanism by a sleeve on a surface of the

Valve sleeve (54) formed stop ring (68) is limited, wherein the stop ring (68) on a valve housing (46) arranged housing stop (70) abuts.

12. Valve arrangement according to claim 5, wherein the first spring (38) on the

Valve housing (46) is supported and on a first end face (72) engages an approximately hollow cylindrical and sealed on both sides magnet armature (64) and this biasing, wherein by the magnet armature (64) of the Guide ram (48) is guided approximately axially, and a third spring (74) on a second end face (76) of the armature (64) this tensioned and on a on the guide ram (48) axially displaceable and on a housing stop (70) abuttable Stop ring (68) is supported, wherein the stop ring (68) formed on the guide plunger (48)

Carrier projection (82) on a closing stroke away from the housing stop (70) is displaceable.

13. Valve arrangement according to claim 12, wherein in the magnet armature (64) the second spring (60) is supported on a in the same direction as the first end face (72) facing first inner surface (80) and one in the armature (64) and arranged prestressing the support plate (62) fixedly connected to the guide tappet (48), wherein the support plate (62) adjoins an inner surface (78) of the magnet armature (64) opposite the first inner surface (80) in the case of a non-executed additional stroke (h) of the second adjustment mechanism. supported.

14. Valve arrangement according to claim 4, wherein the closing body (50) axially displaceably mounted on one of a valve housing (46) guided end portion (84) of an axially displaceably mounted in the valve housing (46)

Guide ram (48) is guided.

15. Valve arrangement according to claim 14, wherein the end portion (84) of the guide tappet (48) in a guide region (85) of the closing body (50) is radially stepped back and in this case a support plate (62) and an annular surface (90) are formed.

16. Valve arrangement according to claim 15, wherein the closing body (50) strikes against an end face (88) which deflects the closing body (50) with an end face (88) in the case of an additional stroke (h) of the second adjusting mechanism and via the second spring (60) ) is biased, which between the support plate (62) and one of the end face (88) repellent inner surface (91) of the closing body (50) is supported.

17. Valve arrangement according to claim 16, wherein the first spring (60) on the valve housing (46) is supported and biased to the guide plunger (48) magnetically connected armature (64) in the opening direction, one fixed to the guide plunger (48) connected Stop ring (68) on one

Housing stop (70) is approximately applied.

18. Valve-controlled hydraulic machine with a valve arrangement according to one of claims 1 to 17.

19. Valve-controlled hydraulic machine according to claim 18, as far as this is related to the claims 1 to 4, wherein the second spring (60) in one of the closing body (50) closable delivery chamber (8) of the hydraulic machine (1) is arranged and between the Closing body (50) and formed in the delivery chamber (8) supporting device (92) is supported.