EP2696080A1 - Commande électro-hydraulique - Google Patents

Abstract

The system has hydraulic circuit (Z) comprising working lines (12) that are connected with an actuating pressure supply (K). The working lines are connected to a return line (2). A pilot control circuit (K) of load-holding valves (14, 15) comprises a damping device (D), where one of the load-holding valves controls fixed or variable damping in transition from zero position to an adjustable float position. The damping device enables variable damping between the return line and a control pressure supply.

Description

The invention relates to an electro-hydraulic control according to the preamble of patent claim 1.

At one off EP 1 766 246 A or DE 199 19 014 A known electro-hydraulic control is the directional slide a 4/4-Proportionalwegeschieber, in addition to two control positions (eg lifting and lowering) has a zero position in which the hydraulic consumer is hydraulically blocked (both working lines shut off to the return and separated from the pressure source), and a fourth position , in which both working lines are connected to the return (floating position). The load-holding valves are opened simultaneously and fully in the floating position or at the transition to the control pressure supply via the 4/4 proportional directional slide. For example, if an attachment excavated by means of the hydraulic consumer, then the attachment to follow in the floating position on the ground resting bumps must first be lowered slowly enough by adjusting the lowering control position of the 4/4-proportional directional slide on the ground before the float position is adjusted. This is then the responsibility of the driver. If the lowering control position is overrun too quickly to lower, then the attachment falls hard on the ground. Similarly, for example, an attachment in the floating position can be excavated when jumping over a survey and made to jump, after which it hits hard on the ground, because just in the floating position both load-holding valves are fully open and the hydraulic consumer has no significant resistance. Furthermore, in driving a distinctive bottom elevation bring the attachment to jump and hit, because in a control position of the 4/4-proportional directional slider, for example, a certain contact pressure is set on the ground, since the load-holding valves are fully opened.

Out EP 2 466 153 A is an electro-hydraulic control is known, the multi-way multi-position directional slide is a 4/3-proportional valve with pressure pilot controls, in which the floating position without fourth slide position is adjustable in that both pressure piloting their proportional solenoids are energized simultaneously and the same, causing the slide his to return open zero position occupies, and at the same time the pilot pressures are transmitted to the two load-holding valves to control this, so that the working lines are connected via the proportional slide with the return. The zero position of the slide also becomes hydraulic blocking of the hydraulic consumer used. Then the two proportional solenoids are not energized, so that there are no pilot pressures and the load-holding valves remain in their shut-off positions and block the working lines. Despite four positions for the hydraulic consumer, this principle allows for a more cost-effective and structurally simpler three-position proportional valve. The setting of the floating position or the transition to or from the floating position is done quickly. An attachment initially raised by means of the hydraulic consumer and hydraulically blocked can then suddenly fall to the ground. Although it is disclosed to adjust harder or softer by the energization of the proportional solenoid, for example, the transition to the floating position, but this does not prevent the hard impact of the attachment to the ground. In any case, both load-holding valves are controlled with the same control pressures, since both proportional solenoids for the float position the pressure pilot controls, for example via pressure reducing valves, actuate similar.

The invention has for its object to improve an electro-hydraulic control of the type mentioned in that critical or the desired work result impairing movements of a load controlled by the hydraulic consumer can be avoided. Part of the task is thereby, at least in the floating position comfortable, e.g. automatically to be able to act on load movements.

The stated object is achieved with the features of claim 1.

The incorporated in the pilot control damping device ensures at least on the transition to or from and / or during the occupied floating position that load movements are damped in a predetermined or controllable manner. For example, although the float position, for example, without first having to visit the sink control position can be set or turned off very quickly, a load movement occurring is damped and takes place with a time delay which avoids critical states of motion or impairment of a desired result of work by the hydraulic consumer moving implements excludes. In addition, the damper device may even be used to exclude undesired load movements in control positions of the directional pusher, for example on an implement held on the ground at a predetermined contact pressure when it has to negotiate a prominent ground elevation, and in similar situations. In other words, certain operations of the hydraulic consumer in the electrohydraulic control can be quickly and directly adjusted, but the design is monitored via the damper to prevent damage or deterioration of work or damage to the attachment. If the damping is fixed, then it comes in each case in a predetermined manner to the effect in which the load-holding valves are controlled regulated. If you work with variable damping, then the damping can be adapted to the circumstances and adjusted, for example, as needed. This is done for example by pressing a pressure switch or with a program routine of an electronic control, so that an operator does not need to worry about a load moved by the hydraulic consumer, eg under the load itself, is controlled slowly enough. The load holding valves is thus assigned an additional throttle function by the damping device.

The damping device is particularly useful in a 4/3-proportional valve with Druckvorsteuerungen and "electric" floating position, since in this type of slide while the transition to or from the floating position is quickly controlled, but this type of slide is much cheaper and kleinbauender than a four-position proportional valve , The floating position is set in the zero position by controlling the load holding valves. There are two options here. Both pressure pilot controls are actuated identically and simultaneously via their proportional solenoids, and the pilot pressure is regulated via the damper device to the control sides of the load-holding valves. Alternatively, the control pressure from the control pressure supply can be used directly via the retarding damper device to control the load holding valves, for example, when the 4/3-proportional directional slide is in its zero position, which it holds by spring force, the proportional solenoid then not necessarily energized at the same time will need, although the proportional magnets can then participate regulate.

In an expedient embodiment for a fixed damping at least one nozzle is provided in the pilot circuit. About this nozzle, the pressurization is carried out to open at least one load-holding valve with a time delay, i. the load-holding valve slowly and / or only partially opened.

In another embodiment, variable damping is performed proportionally across the damping device utilizing the pressures generated in the pressure pilot controls of the multi-way, multi-position, proportional direction shifter. This means that although the damping device monitors the time delay of the pressurization when controlling at least one load-holding valve, but an additional influence is also possible because the proportional magnets in the zero position, although equal to each other but more or less energized. This alternative is useful when the floating position (control of the load-holding valves in the zero position) by tapping the pressures the pressure pilot controls of the multi-way multi-position proportional directional shifter is set.

In an advantageous embodiment, the damping device for the purpose of variable damping between the control pressure supply or the pressure pilot, the return, and the Aufsteuerseiten the load-holding valves, a 3/2-proportional pressure control valve or a 3/2-way black / white solenoid valve, preferably at The load-holding valves side facing away from two shuttle valves and / or at least one check valve pair of two opposing check valves. The 3/2-way proportional pressure control valve allows, as needed, a variable attenuation einzusteuern. But also the 3/2-way black / white magnetic switching valve allows influencing the damping in the control or Zusteuerung the load-holding valves by this valve from the tapped from the control pressure supply or pressure piloting control pressure pressure fluid to the return leaves and so on the way Delay nozzle acts. By means of the 3/2-way proportional pressure control valve, the delay can be controlled very sensitively variable, for example by reducing the tapped from the control pressure supply or the pressure pilot control pressure on the control side of at least one load-holding valve.

In another expedient embodiment, a, preferably elektroproportionales, throttle valve is provided between the return and connected to the control pressure supply or Druckvorsteuerungen control sides of the load-holding valves, preferably on the side facing away from the load-holding valves of two shuttle valves and / or at least one check valve pair. The delay can be modulated via the electro-proportional adjustable throttle valve.

In a further expedient embodiment, the electrohydraulic control has a proportional pressure control section to which the working lines of the hydraulic consumer are connected in order to regulate, in addition to the pressure control via the slide, pressures in the working lines in an electroproportional manner, similar to a conventional secondary breakage limitation. If the pilot circuit downstream of the pressure control section and this is connected to the return, the pilot circuit or at least a part on a control side of a load-holding valve via the pressure control section to the return can be relieved to vary the damping. This can be expedient, in particular in the floating position of the directional slide, since then the working lines are depressurized.

Suitably, the fixed damping or variable damping is the same for both load-holding valves. Thus, both to and from the hydraulic consumer flowing Pressure fluid throttled to achieve the damping. Alternatively, the fixed or the variable damping for both load-holding valves may be different or be performed differently, or only on a load-holding valve, for example, used for lowering.

Suitably, the fixed or variable damping is brought about the damping device even in at least one control position of the multi-way multi-position slide outside the zero position or floating position to action. This can be done, for example, in a control position in which the hydraulic consumer holds an attachment with a predetermined pressure on the ground, with bumps could cause jumping of the attachment, which is eliminated or minimized by the damping. Thus, in addition to influencing the floating position, the damping device allows a further improvement of the operating behavior and an effect on load movements.

Advantageously, the load-holding valves are connected so that in two control positions of the multi-way multi-position slide (eg lifting and lowering) arranged in the one working line load-holding valve from the other working line via a connected to the pilot control line with aufsteuerbar from the working line pressure is aufsteuerbar , wherein, preferably, the control lines lead to shuttle valves or check valve pairs in the pilot circuit. The shuttle valves or check valve pairs ensure that in the control positions, the pressure from the working lines is brought to the control sides, while in the floating position or zero position, the control pressures of the pressure pilot control or the control pressure of the control pressure supply is brought to the respective control side, and the damping device is effective.

In a structurally simple embodiment, for example, for a fixed damping, each nozzle is arranged on the control side of the load-holding valve in the pilot circuit, wherein the nozzles are sized the same or different.

As an additive or alternative measure, at least one return flow damping system can be provided in the working lines and / or on the control sides of the load-holding valves. This backflow-damping system consists for example of a non-return valve blocking in the outflow direction, which is bypassed in a bypass line of a nozzle which throttles in the return flow direction.

Furthermore, different designs are possible for the load-holding valves. Each load-holding valve is, for example, a bypass valve, which can be bypassed by a check valve in the inflow direction to the hydraulic consumer and is spring-loaded on the intake side from the working line and additionally spring-loaded, but on the control side out of the working line downstream of the check valve and pilot-controlled from the pilot circuit. Alternatively, the load-holding valve, a 2/2-way pressure control valve with integrated check valve (locks in the outflow from the hydraulic consumer), the 2/2-way pressure control valve acted upon by spring force to a backflow blocking position and pressure controlled by controlled passage positions from the pilot circuit becomes.

The electrohydraulic control is expedient part of an electronic hoist control, as is customary on mobile work vehicles, which are equipped with at least one attachment or equippable. Examples of such work vehicles are snow plows, snow grooming vehicles, agricultural machines such as tractors, road maintenance machines, or tillage vehicles. The damping device, which monitors at least the transition to or from the float position and / or the float position to avoid critical movements of an attachment, can either be permanently active or activated at the touch of a button, so that an operator does not care about it needs.

The revelation in the EP 2 466 153 A is hereby incorporated by reference.

Fig. 1

ein Blockschaltbild einer Elektrohydrauliksteuerung einer ersten Ausführungsform, in drucklosem Zustand,

Fig. 2

ein Blockschaltbild einer weiteren Ausführungsform,

Fig. 3

einen Teil eines Blockschaltbildes einer Detailvariante,

Fig. 4

ein Blockschaltbild einer weiteren Ausführungsform,

Fig. 5

ein Blockschaltbild einer weiteren Ausführungsform, wobei zusätzliche Ausstattungsdetails gezeigt sind, die auch in den anderen Ausführungsformen implementiert sein können,

Fig. 6

ein Blockschaltbild einer weiteren Ausführungsform,

Fig. 7

ein Blockschaltbild einer weiteren Ausführungsform,

Fig. 8

ein Blockschaltbild einer noch weiteren Ausführungsform,

Fig. 9

ein Blockschaltbild einer weiteren Ausführungsform,

Fig. 10

ein Blockschaltbild einer weiteren Ausführungsform, und

Fig. 11

ein Blockschaltbild einer weiteren Ausführungsform.

Embodiments of the subject invention will be explained with reference to the drawings. Show it:

Fig. 1

1 is a block diagram of an electrohydraulic control of a first embodiment, in a pressureless state;

Fig. 2

a block diagram of another embodiment,

Fig. 3

a part of a block diagram of a detail variant,

Fig. 4

a block diagram of another embodiment,

Fig. 5

a block diagram of a further embodiment, wherein additional equipment details are shown, which can also be implemented in the other embodiments,

Fig. 6

a block diagram of another embodiment,

Fig. 7

a block diagram of another embodiment,

Fig. 8

a block diagram of yet another embodiment,

Fig. 9

a block diagram of another embodiment,

Fig. 10

a block diagram of another embodiment, and

Fig. 11

a block diagram of another embodiment.

The different embodiments of the electro-hydraulic control S in the Fig. 1 to 11 can be part of an electronic hoist control EHR (not shown in detail) Fig. 1 ), as used in different mobile working equipment. Alternatively, however, such electrohydraulic controls may find use in other areas of high pressure mobile or stationary hydraulics, useful for at least minimizing critical load movements, without the need for an operator of the electrohydraulic controller to necessarily care.

An electro-hydraulic control S according to Fig. 1 For example, as part of an electrohydraulic hoist control EHR is supplied by a pressure source in a pressure line 1 and is connected to a return line 2. A control pressure supply, not shown, is connected to a control pressure line 3, while a further tank line 3 'leads to a tank, for example, the control pressure supply. Another control line 4 is connected to a load pressure signal circuit LS.

The electrohydraulic control S serves to actuate a double-acting hydraulic consumer Z, for example a double-acting hydraulic cylinder, with which a load L can be moved in different directions with precisely adjustable speeds and in each case in certain positions, via a multi-way multi-position directional slide W, which is formed in the embodiment shown as a 4/3-way proportional directional slide with a symbolically indicated spool 5. On the pressure side, a feed regulator 6 is provided. The spool 5 is about Druckvorsteuerungen 7, 8, for example, each with a pressure reducing valve (not shown), and two proportional magnets 9, 10 movable between a total of three positions, namely a lower control position a, an upper control position b and a zero position O, in the connected Working lines 12, 13 are relieved to return 2. A spring assembly 11 helps, for example. to set the middle zero position. The pressure pilot controls 7, 8 are connected via a line 31 to the control line 3, and via a line 32 to the tank line 3 '.

In each working line 12, 13, a load-holding valve 14 and 15 is arranged. In the in Fig. 1 In the embodiment shown, each load-holding valve 14, 15 comprises a check valve 16, which is loaded in the reverse direction by a spring 17, and which is connected to a check valve 20 in a bypass loop is bypassed. The check valve 20 blocks in the outflow direction from the hydraulic consumer Z. The shut-off valve 16 is also pressure-controlled in the reverse direction from the downstream of the check valve 20 from the working line 12 via a pilot line 19, and at a Aufsteuerseite 21 from downstream of the check valve 20 from the working line 12 druckvorgesteuert, as well connected to a pilot control circuit K.

Each control side 21, 21 'of the load-holding valve 14, 15 is connected to a control line 22, 22', in which in the embodiment shown a respective nozzle 23 or 23 'is provided as part of a damping device D integrated in the pilot control circuit K. The nozzles 23, 23 'can be the same size or different sizes. The control lines 22, 22 'cross over to shuttle valves 24, 24' which are interconnected at a node 26 and to which of the working lines 12, 13 e.g. via filter branching control lines 25, 25 'lead to aufzusteuern the load holding valves 14, 15 in the control positions a, b each cross. If, for example, the working line 12 is subjected to pressure (extension of the hydraulic consumer Z), then the pressure medium passes through the check valve 20 the closed shut-off valve 16, while at the same time the pressure from the working line 12 via the control line 25, the shuttle valve 24 and the control line 22 ' Load holding valve 15 aufsteuert on its control side 21 ', so that the pressure medium from the hydraulic consumer Z can be pushed out via the working line 13. Another part of the integrated in the pilot circuit K damping device D is a 3/2-way proportional pressure control valve 27 which is adjustable by a proportional solenoid 28 against spring force from the position shown, in which a return line 29 is connected to the node 26, while a Control line 30, which carries a control pressure is shut off. The control line 30 leads to the control line 3, which is connected to the control pressure supply to, for example, provides a control pressure of about 20 to 30 bar substantially constant.

The zero position O of the 4/3-way proportional directional valve W is used both to a hydraulic blockage of the hydraulic consumer Z in its respective position (holding the load L), as well as for setting a floating position, in both working lines 12, 13 with the return 2 are connected. Only to adjust the floating position are in the zero position O befindlichem proportional directional slide W, the two load-holding valves 14, 15 controlled controlled by the damping device D from the control line 30, for which the proportional solenoid 28 is energized accordingly. In conjunction with the nozzles 22, 23 and the choice of the loading force of the proportional solenoid 28, the load-holding valves 14, 15 are only partially or delayed controlled, so that a movement of the load L takes place with a time delay. The stronger the proportional magnet 28 is energized, the more pressure is reduced from the control line 30 in the return line 29, and the less far are the Load holding valves 14, 15 open. The load-holding valves then act as brake valves or throttles, which allow the load movement to proceed only with a delay, although the 4/3-way proportional directional slide W is in its zero position and connects both working lines 12, 13 with the return line 2.

The embodiment of the Fig. 2 is different from that of Fig. 1 by the formation of the load-holding valves 14, 15. In this case, in the working lines 12, 13 2/2-way pressure control valves 16 'included, in which the check valve 20' is integrated, and by a respective spring 17 in the direction of the shut-off acted upon and at the Aufsteuerseite 21 and 21 'are precontrolled from the pilot circuit K pressure. The other structure and the function correspond to those of the embodiment of Fig. 1 , The 2/2-way pressure control valves 16 ', the additional task of throttling possibly better than the shut-off valves 16 in Fig. 1 ,

Fig. 3 indicates a detail variant in which in the pilot circuit, a 3/2-way solenoid valve 27 'between the node 26 on the one hand, and the return line 29 and the control line 30 on the other hand, by a black / white magnet 28' between the two Positions is switchable. In this case, the nozzles 22, 23 'of the damping device D can provide a fixed damping at a load movement at least in the floating position or the transition to or from the floating position.

In the aforementioned embodiments, it would be possible to have only one load-holding valve 14 or 15 work dampened by the damping device D, and fully aufzusteuern the other load-holding valve.

In the embodiment of the electrohydraulic controller S in FIG Fig. 4 is generated in the control of the two load-holding valves 14, 15, an imbalance, for which the damping device D is designed and connected in the pilot circuit accordingly.

Furthermore, the provision of the control pressure for controlling the load holding valves 14, 15 differs from that of Fig. 1 to 3 in which Fig. 4 in the zero position O for setting the floating position both proportional magnets 9, 10 are energized equal, so that the pressure pilot controls 7, 8, for example, same pressures lead, which are fed via the control lines 30a and 30b simultaneously in the pilot circuit K. It is crucial that both proportional solenoids 9, 10 are energized simultaneously and the same, so that the slider 5 holds the zero position. The control pressures in the control lines 30a, 30b can be adjusted by selecting the energization of the proportional magnets 9, 10 with each other equal, but in different heights.

The damping device D in Fig. 4 is connected via the shuttle valves 24, 24 'and the control lines 25, 25' to the working lines 12, 13. In the zero position and for adjusting the floating position, the shuttle valves 24, 24 'are switched to the positions shown, in which the control pressure in the lines 30 a, 30 b via the control lines 22, 22', here without nozzles on the Aufsteuerseiten 21, for controlling the Load holding valves 14, 15 is used. However, since a nozzle 33 is arranged in the control line 30a and, downstream of the nozzle 33, a line 34 is led to the return line 29 via a nozzle 35, while the control line 30b extends directly to the shuttle valve 24 '(without nozzle), the left load holding valve 14 becomes less widely controlled, so that it throttles and dampens the outflow of the pressure medium in the working line 12. Of the control lines 25, 25 'branches off connections to the return line 29, in which also nozzles 38 are included, wherein downstream of a respective filter 36, a further nozzle 37 is placed. In the control lines 22, 22 'or only in one of these control lines, a nozzle or can be arranged nozzles, similar to those in the Fig. 1 to 3 ,

Fig. 5 illustrates a further embodiment of an electro-hydraulic control S, with respect to the previously shown additional sections 41 and 47 are shown. The section 41 contains shock valves 42, which connect the working lines 12, 13 with the control lines 22, 22 'and can respond in a shock condition. The section 47, however, serves to additional pressure control, similar to a secondary pressure limiting, mainly the pressure in the working lines 12, 13 in the control positions of the 4/3-way proportional directional valve W. The section 47 includes a 2/2-throttle valve, which between a Shut-off position and throttling control positions pressure and spring-dependent is adjustable, and a shuttle valve 49 which is connected to the load pressure signal circuit, and adjustable by a proportional solenoid against adjustable spring force drain valve 50 to the return.

The damping device D in the pilot circuit of the load-holding valves 14, 15 contains in Fig. 5 that on the basis of Fig. 1 and 2 explained 3/2-way proportional pressure control valve 27 which is held by a spring 55 in a first switching position, and when energizing a proportional solenoid 28 is adjustable in regulating positions. The two control lines 30a, 30b are combined via check valves 39 at a node 40 and connected to an input of the 3/2-way proportional pressure control valve 27 whose other input is connected to the return line 29. On the other hand, the 3/2-way proportional pressure control valve 27 is connected to the node 26, which is in a control line 25, 25 'connecting line 54 between two pairs of opposing check valves 46, 46'. Between the two check valves of each check valve pair 46, 46 ', the control lines 22, 22' are connected. In addition, the damping device D in Fig. 5 in the two control lines 22, 22 'arranged Rückström-Dämpfsysteme 43 (optional), each consisting of a blocking in the reverse flow check valve 44 and a nozzle 45 in a bypass loop of the check valve 44. By means of the 3/2-way proportional pressure control valve 27 can be in accordance with the energization of the Proportional magnet 28 variably modulate the damping in the control of the load-holding valves 14, 15 or regulate. The Zusteuerbewegungen the load-holding valves 14, 15 can be the same or different attenuated via the outflow-damping systems 43 (depending on Düsenbestückung). As an alternative, only one outflow damping system 43 could be arranged in a control line.

In the embodiment of the electro-hydraulic control S in FIG Fig. 6 is the Aufsteuerung or Zusteuerung the load-holding valves 14, 15 damped in that the pressure control section 47 (see Fig. 5 ) is connected in each case via a check valve of each check valve pair 46, 46 'and connecting lines from the control lines 22, 22' to the 2/2-way throttle valve 48 to the pilot control circuit K, the control lines 22, 22 'two further shuttle valves 51, 51' contain, of which lines 52, 52 'lead to the control lines 25, 25'. Between at least one shuttle valve 51, 51 'and the respective upstream side of a load-holding valve 14, 15 may optionally be a Rückström-damping system 43 (not shown) as in Fig. 5 be included. About the proportional solenoid of the drain valve 50, the damping can be at least when controlling the load-holding valves 14, 15 vary. The control lines 30a, 30b of the pressure pilot controls of the 4/3-way proportional directional slide W are connected to the shuttle valves 24, 24 'in order to be able to control the load-holding valves 14, 15 in the zero position in a damped manner.

The in the pilot circuit K in Fig. 7 integrated damping device D at least for controlling the load holding valves 14, 15 differs from those of the previous embodiments mainly in that a 2/2-proportional throttle valve 27 "(electro-proportional throttle) is provided between the node 26 in the control line 54 and the return line 29 The node 26 is located between the non-return valves of the opposing check valve pair 46, which block in the flow direction to the shuttle valves 24, 24 'The control lines 25, 25' for controlling the load holding valves 14, 15 cross in the control positions of the 4/3-way proportional Directional slide W are also connected to the shuttle valves 24, 24 'and connected via the nozzles 37 and 38 to the return line 29.

The embodiment of the electro-hydraulic control S in Fig. 8 is the of Fig. 5 similar. A variable damping of the control of the load-holding valves 14, 15 is possible not only at the transition to or from and during the floating position, but also in the control positions of the 4/3-way proportional directional valve W from whose Druckvorsteuerungen 7, 8, the control lines 30a, 30b are fed, which are combined via check valves 39 and connected to a port of the 3/2-way proportional pressure control valve 27, the second port is connected to the return line 29. On the other hand, the 3/2-way proportional pressure control valve 27 is connected to the node 26 in the control line 54, in which the two check valve pairs 46, 46 'are arranged. The damping can be varied via the proportional magnet 28.

The embodiment of the electro-hydraulic control S in Fig. 9 is the of Fig. 8 similar. However, only the right load-holding valve 15 (eg used to lower the load L) is damped controlled or controlled, while the left load-holding valve 14 from the control line 25 'can be applied, or not at all. The nozzle assembly in the damping device D also contributes to additional or fundamental damping.

The embodiment of the electro-hydraulic control S in Fig. 10 is similar to the Fig. 4 , However, outflow-damping systems 43 are additionally provided in the control lines 22, 22 'to the control sides of the load-holding valves 14, 15. This also allows the Zusteuerbewegung each load-holding valve 14, 15 perform steamed. If appropriate, only one outflow damping system 43 could be provided in one of the two control lines 22, 22 '.

In the embodiment of the electrohydraulic controller S in FIG Fig. 11 At least during the control of the load-holding valves 14, 15, the damping is varied via the proportionally controlled pressures in the control lines 30a, 30b by the pressure pilot controls 7, 8 of the 4/3-way proportional directional valve W. The proportional magnets 9, 10 are the same but different energized to delay the timing or only partially aufzusteuern and so to dampen. In addition, in this embodiment, return flow damping systems 43 are included in the working lines 12, 13, each with a check valve 44 which blocks in the outflow direction, and a nozzle 45 in the line loop surrounding the check valve 44.

Although in the embodiments of the Fig. 4 to 11 The control pressures derived from the control lines 30a, 30b from the pressure pilot controls of the 4/3-way proportional directional shifter W could alternatively also be used in the embodiments of FIGS Fig. 4 to 9 directly the control pressure can be tapped from the control pressure supply bypassing the pressure pilot controls.

The damping function of the damping device D could, for example, by means of a push button or a program routine in an electronic control of the electro-hydraulic control be activated or be, and then run automatically, without an operator needs to worry about it. Thus, a raised attachment would automatically be lowered when adjusting the floating position to ground contact, even after a jumping motion when passing a survey, and could even in a control position, for example, with adjusted ground pressure of an attachment this slows down after a jumping motion due to a bottom elevation again to ground contact and lowered until the set ground pressure builds up. In a piste grooming vehicle, a significantly improved work result can thus be achieved.

Claims (15)

Electrohydraulic control (S) of at least one double-acting hydraulic consumer (Z) for moving a load (L) via a multiway multi-directional directional valve (W) having pressure piloting (7, 8), with in both working lines (12, 13) of the hydraulic consumer (Z ), at least from one with a pilot pressure supply (3) connected pilot circuit (K) derivable control pressure hydraulically aufsteuerbaren load-holding valves (14, 15), wherein the multi-way multi-position slide (W) a zero position (O) for the hydraulic consumer (Z) in which both working lines (12, 13) are connected to a return (2), characterized in that the pilot circuit (K) of the load-holding valves (14, 15) has a damping device (D) which, at least at the transition into or from the and / or in the zero position (O) adjustable floating position, the control of at least one of the load-holding valves (14, 15) with either fixed or varia bler damping controls. Electro-hydraulic control according to claim 1, characterized in that the multi-way multi-position directional valve (W) a 4/3-proportional valve with Druckvorsteuerungen (7, 8) and with the return (2) open, the working lines (12, 13) from a pressure source (1) insulating zero position (O) and the floating position by controlling the load holding valves (14, 15) via the damping device (D) either directly from the two simultaneously and proportionally proportionally controlled, to the control pressure supply (3) connected Druckvorsteuerungen (7, 8 ) or directly with control pressure from the control pressure supply (3) is adjustable. Electrohydraulic control according to claim 1, characterized in that the damping device (D) in the pilot circuit (K) for a fixed damping at least one nozzle (23, 23 ', 33, 35, 45). Electrohydraulic control according to claim 1, characterized in that the variable damping via the damping device (D) from the Druckvorsteuerungen (7, 8) of the multi-way multi-position directional slide (W) by means of proportional magnets (9, 10) is proportionally executable. Electrohydraulic control according to claim 1, characterized in that the damping device (D) for variable damping between the control pressure supply (3) and the Druckvorsteuerungen (7, 8) and the return (2) and the Aufsteuerseiten (21, 21 ') of Load holding valves (14, 15) contains a 3/2-way proportional pressure control valve (27) or a 3/2-way black / white switching valve (27 '), preferably on the sides of two shuttle valves facing away from the load-holding valves (14, 15) (24, 24 ') and / or at least one check valve pair (46, 46') of oppositely connected check valves. Electrohydraulic control according to Claim 1, characterized in that the damping device (D) for variable damping between the return (2, 29) and the control sides (21, 21 ') connected to the control pressure supply (3) or the pressure pilot controls (7, 8) Load holding valves (14, 15) a, preferably electro-proportional, 2/2-way throttle valve, preferably on the side of the load-holding valves (14, 15) facing away from two shuttle valves (24, 24 ') and / or at least one check valve pair (46, 46 '). An electro-hydraulic controller according to claim 1, characterized in that a proportional pressure regulating section (47) connected to the working lines (12, 13) is provided for the working pressures in the working lines (12, 13) in control positions of the multi-way multi-position directional shifter (W), and the pilot control circuit (K) for carrying out the variable damping is connected downstream of the proportional pressure control section (47) and can be relieved controlled via the proportional pressure control section (47) to the return line (2). Electrohydraulic control according to claim 1, characterized in that the fixed or the variable damping for both load-holding valves (14, 15) is the same or different. Electrohydraulic control according to claim 1, characterized in that the fixed or the variable damping via the damping device (D) in at least one control position (a, b) of the multi-way multi-position directional slide (W) outside the zero position or floating position is adjustable. Electrohydraulic control according to at least one of the preceding claims, characterized in that in the two control positions (a, b) of the multi-way multi-position directional slide (W) each in the one working line (12, 13) arranged load-holding valve (14, 15) of the respective other working line via a to the pilot circuit (K) connected control line (25, 25 ') is aufsteuerbar, wherein, preferably, the control lines (25, 25') to shuttle valves (24, 24 ') or check valve pairs (46, 46') in Feed pilot circuit (K). Electrohydraulic control according to claim 3, characterized in that in the pilot circuit (K) in each case a nozzle (23, 23 ') on the control side (21, 21') of the load-holding valve (14, 15) is arranged, wherein the nozzles are the same or different sized , Electrohydraulic control according to Claim 2, characterized in that separate control lines (30a, 30b), each for one of two shuttle valves (24, 24 ') in the pilot circuit (K) , are provided by the pressure pilot controls (7, 8) of the multi-way multi-position directional valve (W). lead, and that in only one of the control lines (30a, 30b), a nozzle (33) is arranged. Electrohydraulic control according to at least one of the preceding claims, characterized in that in the working lines (12, 13) and / or in control lines 22, 22 'to the Aufsteuerseiten (21, 21') of the load-holding valves (14, 15) Rückström-Dämpfsysteme (43 ) are arranged, preferably each consisting of a non-return valve blocking in the outflow direction (44) and a nozzle (45) bypassing the check valve (44). Electrohydraulic control according to claim 1, characterized in that each load-holding valve (14, 15) either one of a check valve (20) in the inflow bypassable discharge valve (16) on a supply side upstream of the working line (12, 13) under pressure and spring-loaded and at the Aufsteuerseite (21, 21 ') downstream of the check valve (20) from the working line (12, 13) and from the pilot circuit (K) is pressure-controlled, or a 2/2-way pressure control valve (16') with integrated check valve ( 20 '), wherein the 2/2-way pressure control valve (16') acted upon by spring force (17) to a return flow blocking position and is pressure-controlled to variable passage positions from the pilot circuit (K). Electrohydraulic control according to at least one of the preceding claims, characterized in that the electrohydraulic control (S) is part of an electronic hoist control (EHR) of a mobile work vehicle with at least one attachment operated by the hydraulic consumer (Z).

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