DE102005033577A1 - Hydraulic valve arrangement has operating element located to side next to slide of control valve and is pivotable transversely to direction of movement of slide - Google Patents

Abstract

The hydraulic valve arrangement, with a control valve which has a slide (4) and which is located between a supply connection arrangement and a working connection arrangement, and with an operating element (24) which interacts with a valve element (23) which interacts with a pilot valve seat (22), has the operating element located to the side next to the slide and is pivotable transversely to the direction of movement of the slide. A longitudinal axis of the operating element and a longitudinal axis of the slide are arranged in relation to each other without crossing.

Description

The The invention relates to a hydraulic valve arrangement with a supply connection arrangement, the one inflow connection and a Having drain connection, a work connection arrangement, the has at least one working connection, a slide valve having a control valve, which between the Supply connection arrangement and the work connection arrangement is arranged, and at least one check valve between the control valve and a work connection, that by a mechanically actuated Pilot valve is aufsteuerbar, which cooperates with a valve element actuator on which a control surface acts on the slide.

A Such a valve arrangement serves, for example, a hydraulic To drive motor. The engine can, for example, as a piston-cylinder unit be formed, with which a load to be raised or lowered can. To ensure, that one lifted load in a certain position, you can Use the check valve, which ensures that without appropriate control no hydraulic fluid into the valve assembly or can flow out of it. In appropriate Way can be with such a valve arrangement also another hydraulic Operate consumers in which a pressing or pulling load occur can.

If the valve assembly controls the consumer, the check valve open become. For this purpose, hydraulically controllable pilot valves are known. However, these require for controlling a hydraulic pressure. If the hydraulic pressure is missing, for example in case of failure of Drive motor of a self-propelled machine or a Tractor, then the hydraulic consumer can not be operated. For example, a load may no longer be in a safe position be lowered.

you has therefore proposed a mechanically open pilot valve, that is actuated by the slider becomes.

So shows DE 40 28 887 C2 a hydraulic valve assembly of the type mentioned. Each working port has a check valve, which can be opened via a pilot valve. The pilot valve has a guided in the housing actuator, the tip of which rests on the slider. The slider has a conical control surface for each actuator. When the slider is moved, then moves the tip of the actuator, the inclined control surface up and the slider is moved in its longitudinal direction.

A similar embodiment is made DE 103 25 294 A1 known. Here the pilot valve is disconnected from the check valve.

A Such a configuration has the disadvantage that during the operation of the Pilot valve relatively large personnel to act on the slider. This results in considerable wear. The opening of the Need pilot valve Force (overcoming of hydraulic pressure force plus spring force) acts undiminished radially on the slide. The resulting friction forces act especially during electrical operation by a large hysteresis disadvantageous.

US 3,854,499 shows a hydraulic valve assembly in which the check valve is opened directly by the slide. The check valve has a valve member provided with an actuator which stands up on the slider. When the slider is moved, then the actuator is tilted and thereby pivots the valve element, which lifts in this way from the valve seat. In this embodiment, although the forces acting between the actuator and the slider forces are lower. However, you need different forces, depending on which direction you move the slider. During a movement of the slide in the closing direction, the actuating element can catch on the slide in the worst case.

Of the Invention is based on the object, the operation of a hydraulic To facilitate valve arrangement.

These Task is in a hydraulic valve assembly of the above solved by the type mentioned, that this actuator arranged in the direction of movement of the slide laterally adjacent to the slide is and is pivotable transversely to the direction of movement of the slider.

When the slide is moved, the valve element lifts off the valve seat. This movement is a pivoting movement, because the valve element is largely rigidly coupled to the actuating element. Accordingly, it requires relatively small forces to open the pilot valve. The valve element is no longer resting on the slide. The risk that the actuator can get caught on the slider in any way during a movement of the slider, is low. Accordingly, the wear in a contact zone between the Betätigungsse Lement and the slider kept small. The frictional forces that occur between the slider and the actuator are approximately equal in both directions of movement of the slider.

Preferably are a longitudinal axis of the actuating element and a longitudinal axis the slider arranged without crossing each other. The actuator is for example rod-shaped. In this case, the longitudinal axis forms the central axis of the pole. When the two longitudinal axes are crossing each other are arranged, then there is no danger that on a contact surface between the actuator and the slider too big personnel Act.

in this connection is particularly preferred that the actuator forms a tangent to the slider. The actuator is therefore always of the largest diameter the slider is applied, so that here is an optimal power transmission guarantee can.

Preferably is the pilot valve laterally to the direction of movement of the slider staggered. This has the advantage that the actuating element, so to speak rectilinear can act on the valve element and thus on the pilot valve. If you provide a hole to accommodate the pilot valve, then this hole can be made on a conventional drill be without one any oblique holes must generate.

Preferably the valve element is pivotable about a pivot axis, the Edge or outside a sealing area is located. This decouples the sealing area from the swivel range. The danger that by repeated pivoting of the Valve element wears the sealing area and is damaged, is therefore kept small. The pilot valve can last for a very long time be sealed, which in turn also the check valve tight is held.

in this connection it is preferred that the Valve element cooperates with a valve seat, of a recess is surrounded, wherein the valve element projects laterally beyond the valve seat. In this case, the pivot axis is practically through the radially outer edge the valve seat or the radially inner edge of the recess formed. Only there could be result in wear. Furthermore the valve seat remains "tight".

Preferably the valve element is guided in a bore whose diameter with the largest diameter of the valve element coincides, wherein the valve element has a peripheral boundary which tapers conically tapered away from the valve seat. This ensures, on the one hand, that the valve element always comes into contact with the valve seat in the correct orientation. On the other hand, a tilting of the valve element with respect to the Valve seat allows.

Also is advantageous when the pilot valve is arranged in a pilot valve housing is that to a control valve housing is scheduled. In this case, major changes to the control valve are not required.

Also is beneficial if the control surface on an extension the slider is arranged. In this case you can also use the slider with the grooves and rings, the for the control of the other hydraulic functions are required, unchanged leave. The additional for the Actuation of the pilot valves or the necessary space is through an extension provided by the slider.

Preferably corresponds to a distance between a position where the slider on the actuator acts, and a valve seat of the pilot valve at least 10 times the radius of the valve seat. This will be a relatively large lever created so that the Pilot valve can be opened even with low forces, if relative high pressures on the valve element in the closing direction Act.

Preferably has the valve element on its side facing away from the valve seat a projection which upon pivotal movement of the valve element against a closing spring suppressed. A closing or return spring for the Valve element is in many cases anyway available. If the projection now presses laterally against this return spring, then acts on closing the pilot valve in addition a force component directed against the pivoting direction. The valve element then comes with increased reliability Attachment to the valve seat.

Also is beneficial if both working connections, each with a check valve are provided, each of which by a mechanically actuated pilot valve aufsteuerbar, wherein the actuating elements both pilot valves in a common area with the slide interact. One can then open the actuation of the pilot valves simple way to match. The processing of the slider is simplified.

in this connection it is preferred that the actuators arranged offset to one another in the direction of movement of the slide are. In this case, only one pilot valve is opened at a time while the others remain closed. This is a relatively safe operation for the Valve assembly.

Also is advantageous if the slider has a groove in the direction of movement the slider of two control surfaces is limited, wherein in an neutral position of the slider, an actuating element a control surface and the other actuator the other control surface is arranged adjacent. When the respective actuators the respective control surface practically touch, then is already at a very small movement of the slide opening the respective pilot valve. If the distance is slightly larger, then you let in one slide small movement to before opening the Pilot valve is initiated.

The Invention will be described below with reference to preferred embodiments described in conjunction with the drawing. Herein show:

1 a schematic representation of a hydraulic valve assembly,

2 various sectional views through a valve assembly,

3 a representation for explaining the position of actuators and

4 a modified embodiment of a pilot valve.

1 shows a schematic representation of a hydraulic valve assembly 1 , which can also be referred to as a control device. The valve arrangement 1 has a supply connection arrangement 2 with an inflow port P, can be supplied via the hydraulic fluid under pressure, and a drain port T on. The supply connection arrangement 2 is with a control valve 3 connected. The control valve 3 has a slider 4 on.

The valve assembly further comprises a working port arrangement with two working ports A, B, which with a hydraulic consumer only schematically illustrated 5 , For example, a piston-cylinder device can be connected.

Between the control valve 3 and one working port A is a first check valve 6 arranged. Between the working port B and the control valve 3 is a second shut-off valve 7 arranged. Both check valves 6 . 7 are designed in the manner of a check valve, ie they have a check valve element 8th . 9 on, under the action of a Sperrventilfeder 10 . 11 against a check valve seat 12 . 13 is pressed and thus a fluid path from the working port A, B to the control valve 3 blocked.

In the closing direction acts on the check valve elements 8th . 9 in each case also the pressure in a room 14 . 15 that has a throttle 16 . 17 with the respective working port A, B is in communication.

Each check valve element 8th . 9 has a pressure applied to the working port A, B pressure application surface 18 . 19 which is equal to or larger than the pressure application area in the room 14 . 15 , When the pressure in the room 14 . 15 is lowered, then a force caused by the pressure on the pressure application surface 18 . 19 is exercised, greater than the force of the spring 10 . 11 and the check valve element 8th . 9 is from the check valve seat 12 . 13 lifted.

To lower the pressure in the room 14 . 15 is for each check valve 6 . 7 a pilot valve 20 . 21 intended. Because both pilot valves 20 . 21 are the same structure, the following explanation is made using the example of the pilot valve 20 ,

The pilot valve 20 has a valve seat 22 on, with which a valve element 23 cooperates, on which a closing spring 31 acts to move it toward the valve seat 22 to charge. The valve element 23 is rigid with an actuator 24 connected, extending to the slide 4 of the control valve 3 extends. In this case, the actuating element 24 laterally to the slider 4 offset, ie the actuator 24 lies in the manner of a tangent on the circumference of the slider 4 at. This ensures that the longitudinal axis of the actuating element 24 and the longitudinal axis of the slider 4 run without intersection.

In 1 is a situation illustrated in which both pilot valves 20 . 21 are closed. How out 1a This is made possible by the fact that the actuators 24 the two pilot valves 20 . 21 in a diameter reduction 25 of the slider 4 are arranged, in the direction of movement 28 on both sides by control surfaces 26 . 27 is limited. If now the slider 4 , as in 1b and 1c shown, verla siege, then the two actuators 24 through the control surface 27 relative to the slider 4 pressed radially outward and thereby about a pivot axis 29 pivoted, parallel to the longitudinal axis 30 of the slider 4 runs. The pivot axis 29 can also be very short, so that it is designed in principle as a pivot point when the valve element 23 is circular. As the valve element 23 each rigid with the actuator 24 is connected, the valve element 23 also pivoted and lifts it from the valve seat 22 from.

In the embodiment of 1a and 1c has the diameter reduction 25 a Length in the direction of movement 28 of the slider 4 that is about the extension of the actuators 24 in this direction corresponds. Accordingly, regardless of the direction of movement of the slider 4 both pilot valves 20 . 21 open at the same time. If necessary, then a check valve at the inlet port P must be provided.

1d shows an embodiment in which the diameter reduction 25 of the slider 4 is larger. The actuators 24 are in the direction of movement 28 arranged offset from one another. Each actuator 24 is the control surface assigned to it 27 arranged adjacent, so that upon movement of the slider 4 in the direction of movement 28 always just a pilot valve 20 . 21 is opened.

It can be seen that the two pilot valves 20 . 21 laterally next to the slider 4 are arranged so that in a neutral position of the slider, the two actuating elements 24 extend parallel to each other.

2 now shows in various sectional views an actual embodiment of a valve assembly 1 , 2a shows a section CC after 2c , 2 B shows a section AA after 2a and 2c shows a section BB after 2 B , 2d shows again an embodiment of the operation of a slider 1d where after the shift of the slider 4 only one actuator 24 has been pivoted. The other actuator, however, remains in the rest position, so that the corresponding pilot valve 21 remains closed.

The valve arrangement 1 to 2 has a control valve housing 32 on, in which the slider 4 is arranged. Same elements are denoted by the same reference numerals as in FIG 1 Mistake.

The two pilot valves 20 . 21 are in a pilot valve housing 33 arranged on the control valve housing 32 is flanged. To operate the two pilot valves is the slide 4 with an extension 34 Mistake. In the extension then the diameter reduction 25 arranged.

The two pilot valves 20 . 21 are each via lines 35 . 36 in the control valve housing 32 are formed with the check valves 6 . 7 in connection. As in particular from 2c it can be seen, are the pilot valves 20 . 21 in holes 37 . 38 arranged, with the holes 37 . 38 transverse to the longitudinal axis 30 of the slider 4 are offset. The two pilot valves 20 . 21 are, as indicated by the location of the holes 37 . 38 in 2 B can be seen, also in the direction of movement 28 of the slider 4 staggered to each other. This makes it possible to use the two pilot valves 20 . 21 independently opens and closes.

3 again shows an enlarged view of the positions of the actuators 24 in relation to the slider 4 , It can be seen that in 3 left illustrated actuator 24 in the direction of view in front of the slider 4 is arranged while in the 3 right illustrated actuator 24 is arranged behind the slide in the direction of view, so that it passes through the slide 4 partially obscured.

4 shows a modified embodiment of the pilot valves 20 . 21 where the pilot valve 20 in open and the pilot valve 21 is shown in the closed position. Same elements are denoted by the same reference numerals as in FIG 1 and 2 Mistake.

The valve seat 22 is in the design after 4 from an annular recess 39 surround. Accordingly, the valve element tilts 23 at a pivoting of the actuating element 24 so to speak, around the edge 40 of the valve seat 22 , This guaran stet that wear, which could be caused by a repeated tilting movement, not in the sealing zone between the valve seat 22 and valve element 23 occurs but at the edge of this sealing zone or even outside of it. At the same tilt angle, a larger flow area is released and it will be achieved safe closing conditions.

In the embodiment according to 1 and 2 was the valve element 23 cone-shaped, so that it under the action of the closing spring 31 Self-centering in the valve seat 22 has been pressed. This possibility is missing now.

Instead, the valve element 23 an outside diameter equal to the inside diameter of the bore 37 . 38 at the location of the valve element 23 equivalent. This outer diameter does not have to be closed in a circular ring. You can also do it through several projections 41 realize that the valve element 23 surrounded in a star shape. Through the projections 41 (or of course a correspondingly different embodiment) is the valve element 23 appropriately centered in the hole 38 guided.

The valve element 23 but tapers conically from the valve seat 22 away, so that, as of the valve element 23 the pilot valve 20 can be seen, a pivoting movement of the valve element 23 is still sufficiently possible. Through the spaces between protrusions 41 then liquid can flow and through the gap between the valve seat 22 and the valve element 23 flow away.

The valve element 23 points to the from the valve seat 22 opposite side a projection 42 whose outer diameter is equal to the inner diameter of the closing spring 31 is.

If now the valve element 23 is pivoted, then the closing spring 31 not only compressed at least on one side. The lead 42 steers the closing spring 31 also a little laterally. Accordingly, one results on the valve element 23 acting force through the closing spring 31 that is not just the valve element 23 on the valve seat 22 pushes, but also a small component in the pivoting direction on the valve element 23 exercises.

From the illustrated embodiment may be waived in some respects. The throttles 16 . 17 in the check valve elements 8th . 9 may also be omitted if otherwise hydraulic fluid under the appropriate pressure from the working ports A, B in the spaces 14 . 15 can get.

The actuators 24 the pilot valves 20 . 21 lie parallel. However, it is also an angle between the two actuators 24 possible, if this brings advantages from a constructive point of view.

With simultaneous opening of the pilot valves 20 . 31 in the inflow and outflow ( 1a - 1c ) is the actuation curve and thus the entire length of the valve assembly 1 optimally short. If only the outlet side is opened, the entire length becomes slightly longer.

To further reduce the closing time is a check valve 43 . 44 between the room 14 . 15 and the drain port T provided so that hydraulic fluid into the room 14 . 15 can be sucked. Optionally, one can in a modified embodiment, the check valves 43 . 44 Also connect to a room in which an auxiliary pressure is present.

Claims (14)

A hydraulic valve assembly having a supply port assembly having an inflow port and an outflow port, a workport assembly having at least one working port, a spool control valve disposed between the supply port assembly and the workport assembly, and at least one check valve between the control valve and a service port; which can be opened by a mechanically actuable pilot valve which has an actuating element interacting with a valve element, on which a control surface acts on the slide, characterized in that the actuating element ( 24 ) in the direction of movement ( 28 ) of the slider ( 4 ) at the side next to the slider ( 4 ) is arranged and transversely to the direction of movement ( 28 ) of the slider ( 4 ) is pivotable. Valve arrangement according to claim 1, characterized in that a longitudinal axis of the actuating element ( 24 ) and a longitudinal axis ( 30 ) of the slider ( 4 ) are arranged without crossing each other. Valve arrangement according to claim 2, characterized in that the actuating element ( 24 ) a tangent to the slider ( 4 ). Valve arrangement according to one of claims 1 to 3, characterized in that the pilot valve ( 20 . 21 ) laterally to the direction of movement ( 28 ) of the slider ( 4 ) is arranged offset. Valve arrangement according to one of claims 1 to 4, characterized in that the valve element ( 23 ) about a pivot axis ( 29 ) is pivotable, which is located at the edge or outside a sealing area. Valve arrangement according to claim 5, characterized in that the valve element ( 23 ) with a valve seat ( 22 ) cooperating with a recess ( 39 ) is surrounded, wherein the valve element ( 23 ) laterally over the valve seat ( 22 ) survives. Valve arrangement according to claim 5 or 6, characterized in that the valve element ( 23 ) in a bore ( 37 . 38 ) is guided whose diameter with the largest diameter of the valve element ( 23 ), wherein the valve element ( 23 ) a peripheral limitation ( 41 ), which tapers conically from the valve seat ( 22 ) Tapered away. Valve arrangement according to one of claims 1 to 7, characterized in that the pilot valve ( 20 . 21 ) in a pilot valve housing ( 33 ) is arranged that to a control valve housing ( 22 ) is set. Valve arrangement according to one of claims 1 to 8, characterized in that the control surface ( 26 . 27 ) on an extension ( 34 ) of the slider ( 4 ) is arranged. Valve arrangement according to one of claims 1 to 9, characterized in that a distance between a position at which the slide ( 4 ) on the actuator ( 24 ), and a valve seat ( 22 ) of the pilot valve ( 20 . 21 ) at least 10 times the radius of the valve seat ( 22 ) corresponds. Valve arrangement according to one of claims 1 to 10, characterized in that the valve element ( 23 ) on its the valve seat ( 22 ) facing away from a projection ( 42 ), which during a pivoting movement of the valve element ( 23 ) against a closing spring ( 31 ) presses. Valve arrangement according to one of claims 1 to 11, characterized in that both working ports (A, B) each with a check valve ( 6 . 7 ), each of which is controlled by a mechanically operable pilot valve ( 20 . 21 ) is controllable, wherein the actuating elements ( 24 ) of both pilot valves ( 20 . 21 ) in a common area ( 25 ) with the slider ( 4 ) interact. Valve arrangement according to claim 12, characterized in that the actuating elements ( 24 ) in the direction of movement ( 28 ) of the slider ( 4 ) are arranged offset from each other. Valve arrangement according to claim 13, characterized in that the slide ( 4 ) a groove ( 25 ), which in the direction of movement ( 28 ) of the slider ( 4 ) of two control surfaces ( 26 . 27 ) is limited, wherein in a neutral position of the slide ( 4 ) an actuating element ( 24 ) of a control surface ( 26 ) and the other actuator ( 24 ) of the other control surface ( 27 ) is arranged adjacent.