DE4118823A1 - Active suspension for vehicle with fail=safe mode - has fail=safe valves for each unit to control fluid flow to and from unit - Google Patents

Abstract

The active suspension has a control valve system (44 to 77) for each unit. The safety system is operated if a defect is detected. This system takes over the suspension control and has separate valves to connect the suspension unit to the supply and to the return flow. The valves are normally held closed by springs and are operated by solenoids. The solenoid current is controlled to regulate the open position of the valves, thereby controlling the fluid. The system includes sensors for pressure, displacement and dynamic forces. ADVANTAGE - Uses minimum of fluid flow, efficient control, failsafe.

Description

The invention relates to a pitch and roll system control or leveling, especially when driving stuff, preferably a motor vehicle. Specifically relates the invention on control systems for pitch and roll control using damper systems of hydropneumatic Type.

So-called "slow active" active springs are already known and are used to regulate line frequencies from approx. 2 to 5 Hz used. This is in contrast to the active spring, at of the line frequencies up to 25 Hz are to be corrected.

A control system is already known which uses a Pressure sensor is pressure controlled and a 3/3-way proportional valve controlled by two proportional solenoids. For reasons security is eliminated via the central pressure supply lockable check valves controlled. That is, under pressure the actual damper cylinders from Regelven fail til switched off. It is disadvantageous that the failure of Electronics with a time delay via a two-way valve in the Close to the pressure supply unit can be switched off. over the discharge of the control line to the unlockable back impact valves, the pressure is only released, d. H. the sure system reacts with a delay.

There has also been the use of a pressure control valve proposed for controlling a damper cylinder. The Pressure is fed back purely mechanically-hydraulically.  

The security concept used here provides that over a central electrohydraulic "multivalve" every four pressures control valves are switched off.

Another system using a pressure control valve the pressure feedback does not see via pressure sensors, but via a hydraulic line. The security concept works here so that a bypass valve as a pre control valve for a shut-off valve on the one hand the pressure directly is degraded - at z. B. Power failure - and through input tax the consumer pressure to the steamer via the shut-off valve is prevented. As is well known, the piloted or the directly controlled pressure control valves a less favorable one Have amplitude response than the directional control valves, is the total dynamics of such a system bad.

It is also known to use damper cylinders via so-called servos control valves. The energy consumption is relative high because large line frequencies have to be corrected. In such a case, the total liter output is reached together with 40 to 50 l / min. In this case, very expensive servos valves with expensive preamplifiers, most of the time work on the basis of torque motors, which in turn are expensive and are sensitive to contamination.

The present invention is based on the object To avoid disadvantages of the prior art. In particular aims the invention, a control system for damper systems to provide, which has a high dynamic. That invented system according to the invention is particularly for pitch and roll control suitable for motor vehicles.

To solve this problem are in claim 1 and the measures provided for other claims.

Further advantages, aims and details of the invention result itself from the description of exemplary embodiments on the basis of the Drawing; shows in the drawing

Fig. 1 shows diagrammatically for only one wheel of a vehicle, a pitch and Wankregelsystem according to the prior art;

Fig. 2 shows a known embodiment of the system of Fig. 1;

FIGS. 3 and 4, a further known embodiment of the system of FIG. 1;

Fig. 5 shows a first embodiment of a pitch and Wankregelsystems invention;

Fig. 6 shows a detail of Fig. 5;

Fig. 7 shows a second preferred embodiment of a pitch and Wankregelsystems according to the invention, applied to the four wheels of a motor vehicle;

Fig. 8 shows the circuit of a third embodiment of the invention;

Fig. 9a and 9b, the circuit of a fourth embodiment of the invention;

FIG. 10 is the circuit of a fifth embodiment of the invention;

Fig. 11, the circuit of a sixth embodiment of the invention;

FIG. 12 is the circuit of a seventh embodiment of the invention;

FIG. 13 is the circuit of an eighth embodiment of the invention;

Fig. 14, the inventive construction of a 3 / as it is preferably used in the realization of the circuits explained above, 3-way proportional valve;

Fig. 15, the symbolic representation of the directional proportional valve of Fig. 14.

FIG. 16 is a summary circuit;

Fig. 17 shows the circuit of a ninth embodiment of the invention;

FIG. 18 is the circuit of a tenth embodiment of the invention;

FIG. 19 is the circuit of an eleventh embodiment of the invention; and

Fig. 20, the circuit of a twelfth embodiment of the invention.

In Fig. 1, a known pitch and Wankregel is shown system 1 schematically having a damper system 2 and Ven tilmittel. 3 The valve means 3 are used to connect a connection A of the damper system 2 , based on information supplied via a line 20, either to a pump P connected to line 21 or to a tank T connected to line 22 . The damper system 2 has a designated as a whole with 4 hydropneumatics that can be fully or partially supporting. In the case of part wearing a dashed additional mechanical cal spring 5 is connected in parallel to the hydropneumatics 4 . 1 in detail can be seen in Fig. 9, a single wheel, which is supported via a piston rod 8 of a piston 7, which forms in a hydraulic or damping cylinder 6 has two piston chambers 11 and 12. The damper cylinder 6, as shown at 10, secured to the vehicle frame 10th The two piston chambers 11 and 12 are connected via a connecting line 13 , which is also connected via line 19 to the connection A and a line 17 , which leads via a damping element 18 to a pressure accumulator 14 which has a gas chamber 15 and a liquid chamber 16 in a known manner.

The damping element can also be installed in the line 13 between the two piston spaces 11 and 12 .

Fig. 2 shows a special embodiment of the valve means 3 in the form of a 2/2-way valve 25 , which is supplied by a mechanical control linkage 26 with, so to speak, "mechanical" information, for example via the path covered by the piston 8 . Accordingly, the setting of the 2/2-way valve 25 takes place .

FIGS. 3 and 4 show the use of a pressure regulating valve 27, which provides the connection between A and P and T on the basis of the supplied via a line 28 electrical information. In Fig. 4, the pressure control valve is designated 29 with net. Apertures 230 , 240 and 340 are also shown. In üb ring, however, the Fig. 3 and 4 correspond to what the function demands. The following is disadvantageous in the arrangement according to FIGS. 3 and 4:

• - Constant control oil volume flow through the orifice 230 ;
• very small diameter of the orifices 230 , 240 and 340 required to achieve stable behavior;
• - Pressure feedback can only be proportional (P controller) respectively. This leads to control deviations when the amount of oil is added or removed must be dissipated.

FIGS. 5 and 6 show schematically a first Ausführungsbei the invention play shown for only one wheel of a motor vehicle. Again, it detects the leading already in FIGS. 1 to 4 for existing terminal A line 19, with the FIG. 5 is a way proportional valve 30 is connected, to produce the compound with P or T. The Wegeproportionalven til 30 has a proportional magnet 41 on one side, while on the opposite side a spring 42 brings the proportional valve 30 in the rest position shown when he is not excited proportional magnet 41 . The proportional magnet 41 is controlled by a control circuit 33 , which is on the input side via a line 32 with a pressure sensor 31 , which is connected to line 19 . In particular, the control circuit 33 has a comparator 34 , which is connected to a PI controller 36 via a line 35 . The PI controller 36 is connected via a line 39 to an offset circuit 37 , from which a control signal I is then applied to the proportional magnet 41 via a line 40 . Via the line 32 , a pressure actual value is supplied in the comparator 34 , which is compared with a set value supplied via the set value input 38 . Instead of a pressure signal, a force signal, a path signal or an acceleration signal can also be used.

In practice, a system according to FIG. 5 is assigned to each of the four wheels of a motor vehicle, with the connections correspondingly taking place as is explained in the following exemplary embodiments.

Fig. 6 shows the symbol of the directional proportional valve 30 in a more detailed representation than in Fig. 5. It should be noted that in the present embodiment, as well as the embodiments to be described, piloted or directly controlled directional proportional valves can be used, which of the amount depends. Pre-control is used for large quantities, direct control for small quantities. As mentioned, a proportional magnet 41 , which works against the spring 42 , is preferably used.

Fig. 7 shows a second embodiment of a pitch and Wankregelsystems, and indeed for all four wheels, the respective associated damper systems 2 are shown schematically. These four damper systems 2 are connected to corresponding connections A 1 , A 2 , A 3 and A 4 of a valve block 43 via lines 114 , 214 , 314 , 414 . Further series circuits 33 are shown in FIG. 5 corresponding control circuits 133, 233, 333, 433 are provided, which are connected to corresponding pressure sensors 31 as shown in Fig. 5 the manner shown with the damper system 2.

On the output side, the control circuit 133 , 233 , 333 and 433 are connected via control lines 78 , 75 , 77 , 76 to proportional solenoids 44 , 45 , 46 , 47 which are still to be explained.

In the exemplary embodiment shown, the valve block 43 has pilot-controlled directional proportional valves 44 to 47 . Directly controlled directional proportional valves can also be used. Each of the directional proportional valves 44 to 47 is preferably a 3/3-way valve and generally with a small positive overlap, but under-coverage is achieved in practice by the known chopper control. Each damper system 2 is assigned one of the directional proportional valves 44 to 47 , which are connected on the input side to P or T, via lines 65 , 66 , 67 , 68 , 69 and 70 .

For safety reasons, a safety valve 51 , 52 , 55 and 56 is assigned to each of the directional proportional valves 44 to 47 . The directional proportional valve 44 is connected via a line 63 to the safety valve 51 , which in turn is connected via line 60 to a line 59 leading to connection A 1 . The directional proportional valve 45 is connected via a line 64 to the safety valve 52 , which in turn is connected via a line 62 to a line 61 which leads to the connection A 2 . The lines 59 and 61 connect the two connections A 1 and A 2 with the interposition of a cross check valve 48 . The cross check valve 48 is a 2/2-way valve, which has a throttle position as the rest position, which is provided by a throttle 480 . A spring 481 presses the 2/2-way valve 48 into its throttle position when it is not brought into its blocking position by a control pressure. Control pressure can be supplied to the cross check valve 48 via a line 72 if a safety pilot valve 50 connects to the line 72 in the pump line 65 . It can be seen that, in the case illustrated in FIG. 7, the pilot safety valve 50 is in its non-excited state, where an unspecified spring has brought the pilot safety valve 50 into the position shown, where the line 72 via line 66 to the tank T communicates. As a result, the cross-blocking valve 48 is also not activated and is also in the position shown in FIG. 7.

Before the symmetrical configuration of the circuit with regard to the valves 45 , 46 and 47 is discussed, it should be pointed out that the control line 72 is connected via lines 71 to the safety valves 51 , 52 , 55 and 56 in order to if control pressure is available to switch to its open position. After there is no control pressure on line 72 in the illustrated case, the valves 51 , 52 , 55 and 56 take the blocking positions shown, which is achieved by the associated springs 53 , 54 , 57 and 58 . Finally, the line 72 is still in connection with the transverse valve 49 assigned to the rear axles, which in the switched-on position places the throttle designated 490 between the connections A 3 and A 4 and is biased by a spring 491 into the position shown in FIG. 7 .

In view of the foregoing, due to the symmetrical structure, a closer look at the connecting lines for the valves 46 and 47 can be dispensed with.

According to the invention, a directional proportional valve 44 to 47 is assigned to each damper cylinder or damper system 2 , which can be controlled separately and what can regulate the damper path or pressure separately (it is therefore possible to carry out a force regulation or a position regulation on the damper cylinder either selectively or simultaneously. As with the arrangement according to FIG. 5, each of the damper systems 2 can , as shown, be fully load-bearing, but possibly also partly load-bearing, together with a mechanical spring.

As far as the safety concept is concerned, it should also be noted that the pilot safety valve 50 is preferably designed as a 3/2-way switching valve and controls the 2/2-way seat valves (safety valves) 51 , 52 , 55 and 56 , which are preferably designed as seat valves. It is thereby achieved that when a power failure occurs, the pilot safety valve 50 reaches the position shown by the associated spring and thus connects the control line 72 to tank T. This has the consequence that all safety valves 51 , 52 , 55 and 56 designed as seat valves move into their closed position, so that the damper systems 2 of pump P and tank T are completely separated.

At the same time, however, the two transverse shut-off or throttle valves 48 , 49 are actuated, each of which sits between the systems in the damper systems 2 of the front axle and the two steamer systems 2 of the rear axle. The circuit is provided such that the throttles 480 , 490 are switched on in the event of a power failure and the cross-connection to the individual damper systems 2, the axis is interrupted during normal operation of the damper systems 2 . This has the advantage that when there is a power failure in a curve, the vehicle is not at an angle when driving straight ahead. If these cross shut-off / throttle valves 48 , 49 were not present, the pressures to the individual damper systems 2 and the associated pressure accumulators 14 would be interrupted, as just described, and the vehicle could accidentally be inclined. Any misalignment of the vehicle due to asymmetrical loading is reduced by the axle geometry and possibly by the steel spring present in the partially carrying version.

In the embodiment of FIG. 7, it is advantageous that all valves can be accommodated in the common valve block 43 , which can be arranged in the middle part of the vehicle or on the front or rear axle.

FIG. 8 shows a third preferred exemplary embodiment of a hydraulic circuit similar to the circuit according to FIG. 7, but here two valve blocks 80 and 81 are provided. One valve block 80 here has connections P and T, which are connected to the pump and tank, and two further connections T and P, which are connected to corresponding connections T and P of block 81 . Lines 167 , 168 run between these two connections. Another line 172 is used for connecting the terminals X of the blocks 80 and 81 to transmit to the on line 71 geliefer from the pilot safety valve 50 th or not control pressure supplied to the valve block 81st The valve block 80 is assigned to the front axle, while the valve block 81 is assigned to the rear axle. The 3/2-way switching valve 50 , which can be referred to as a preliminary stage valve, is only accommodated in one valve block, specifically the valve block 80 here. The pilot line 172 is of course to be laid between the front and rear axles. Otherwise, the function is the same as in the circuit according to FIG. 7.

Figs. 9a and 9b show a fourth embodiment of an inventive circuit for controlling the steamer systems 2. FIG. 9b coincides with the circuit 9 a consistent and shows only how the circuit 9 a of the circuit of FIG. 7 by the omission of the safety switching valves 51, 52, 55 and 56 yields, whereby the safety function now by a common Druckzuführventil 83 and a tank connection valve 84 is provided. Otherwise, each damper system 2 is assigned its own 3/3-way proportional valve 44 or 45 or 46 or 47 , which in turn can be pilot-controlled or direct-controlled depending on the quantity required. Here, too, the control takes place in terms of force or displacement (pressure or acceleration can also be supplied as a force).

The safety concept used here provides that the pressure supply to the directional proportional valves 44 to 47 can be shut off by the common pressure supply valve 83 in the event of a fault. Figs. 9a and 9b show the circuit in the event of an accident, that the pressure supply valve 83 is switched by the spring 85 into the position shown bypass position.

The feedforward control of the pressure supply valve 83 is again via a 3/2-precursor switching valve 50 preferably having equivalent type as the valve 50 in the preceding examples, approximately exporting.

Furthermore, the two-way switching valve or tank connection valve 84 , which can also be referred to as the main stage, is also provided, which can also be actuated by the pre-stage switching valve 50 via control line 91 , 88 . In the illustrated fault, there is no control pressure on control line 91 , control line 88 and also control line 87 , so that spring 86 has moved tank connection valve 84 into the blocking position shown.

As in the previous exemplary embodiments, the transverse control valves 48 , 49 are also provided here, which are also controlled via the 3/2-way valve 50 .

An essential feature of this "fail safe" circuit in the event of a fault, ie in the event of a power failure, is that the damper systems 2 connected to connections A 1 and A 2 or A 2 and A 4 each have the "fail safe" - Position of the 3/3-way proportional valves 44 to 47 are connected. There is the advantage here that the damping systems 2 prevail in all damping cylinders of the damper without much additional circuitry the same surface pressure. It is thus not only prevent a transverse skew in the event of a failure in a curve (through valves 48 , 49 ), but also reliably prevent longitudinal skewing of the vehicle in the event of a failure during an acceleration or braking phase. The same pressure in the rear and front axles is not absolutely desirable, since different loads result from loading and thus a complete sinking of an axle would occur (with a fully load-bearing version). In the case of a partially load-bearing version, the skewing depends on the steel spring rate due to the different loads. A further major advantage of the circuit according to FIGS . 9a and 9b is that, for example, if a valve slide gets stuck, one of the directional proportional valves 44 to 47 still has a cross connection of the damper systems 2 per axis, e.g. B. A 3 and A 4 or A 1 and A 2 , is given via the cross throttle valves 48 , 49 . In the event of a power failure, these are connected to the valve throttle 480 , 490 . Otherwise, the reference symbols are to be understood as in FIG. 7. In addition, lines 165 and 166 connect lines 68 and 69 to outputs of valves 83 and 84, respectively. FIG. 9 b shows the derivation of the circuit 9 a from FIG. 7.

Fig. 10 shows a further embodiment of the invention, in which again all valves are combined in a compact valve block 95. This valve block 95 can in turn be assigned to either the front axle or the rear axle.

As in the other exemplary embodiments, each damper system 2 is assigned a three-way control valve 44 or 45 or 46 or 47 , which can be designed as pilot-controlled or directly controlled.

As far as the safety concept used, in this case pressure supply valves 83 and tank connection valves 84 from FIGS . 9a, 9b are combined in a single pump-tank shut-off valve 840 , which is designed as a 4/2-way valve. The valve 840 is biased into the circulating position shown by a spring 841 and can be brought into the leading position by pilot pressure, which is supplied via line 91 .

In the circuit of Fig. 10 are further also two transverse connecting valves 48, 49 of the previous examples into a single exporting approximately 4/2-way switching valve 149 combined. A spring 891 biases the valve 149 into the throttle position shown. Control pressure supplied via line 91 can switch the valve 149 into the blocking position against the force of the spring 891 . As already indicated, the two valves 149 and 840 are actuated via the safety valve 50 , which is designed as a 3/2-way switching valve. A spring 501 biases the valve 50 to the position shown. As soon as a control current is supplied to the magnet 502 of the valve 50 , the valve 50 establishes the connection between the pump and the control line 91 and at the same time blocks the tank connection.

Although the construction effort for the safety valve main stages, i.e. the valves 149 and 840 , increases, the overall construction effort is reduced.

Fig. 11 shows the sixth embodiment of the invention. It is here to a variant of the circuit shown in Fig. 7. The valve block 160 shown in FIG. 11 differs from the valve block 43 of FIG. 7 only in that the two cross-blocking valves 48, 49 of Fig. 7 to form a single cross-check valve 149 are summarized, namely of similar design, as has already been shown in Fig. 10. A spring 160 biases the valve 149 into the throttle position. Control pressure from the safety valve 50 , supplied via control line 72 , causes the valve 149 to switch into the blocking position.

Fig. 12 shows a seventh embodiment of the invention, in which a valve block 162, in turn, either the front or the rear axle may be associated.

In the valve block 162 , the directional proportional valves 44 to 47 are in turn contained and a safety valve 50 is provided, which applies pilot pressure to two 4/2-way shut-off valves 93 and 94 . If one compares the circuit according to FIG. 12 with that according to FIG. 7, one can see that in the 4/2-way shut-off valve 93 the shut-off valves 51 and 52 and the cross valve 48 of FIG. 1 are combined. In the same way, the check valves 55 and 56 and the cross valve 49 are combined in the valve 94 .

According to the invention, the blocking or connecting throttle are directly integrated into the 4/2-way valves 93 and 94 . The valves 93 are each biased by springs 163 into the blocking or throttle connection position shown and can be switched into the open position by control pressure supplied by the safety valve 50 .

Here too, the directional proportional valves 44 to 47 can be designed directly or pilot-controlled depending on the quantity, although the pilot-controlled version is shown here.

FIG. 13 shows an eighth exemplary embodiment of the invention, which differs from the exemplary embodiment according to FIG. 12 in that the valve blocks 164 , 165 are designed separately for the front and rear axles. The common safety or pilot control valve in the form of a 3/2-way valve for the two 4/2-way shut-off and cross-cut valves 93 , 94 is integrated, for example, the block of the front axle.

It is also possible to provide the 3/2-way switching valve 50 separately for each block in the present separation of the valve blocks 164 , 165 . Then the control line drawn in dashed lines in FIG. 13 would be omitted between the control connections X of the blocks 164 , 165 . The bridging from block 164 to block 165 would then of course take place electrically.

FIG. 14 shows in longitudinal section a preferred embodiment of a 3/3-way proportional valve 100 , as can be used as one of the way proportional valves 44 to 47 in the circuits mentioned above.

The 3/3-way proportional valve 100 has a valve part 101 and a proportional magnet, preferably a Druckpro proportional magnet 102 , formed in a single housing 103 , so that one can speak of an integral valve here, in which the magnet is not formed separately . The housing of the valve part 102 and the housing of the proportional magnet 102 merge into one another.

The 3/3-way proportional valve 100 is shown in its middle position - see also FIG. 15. The proportional magnet 102 is excited with approximately half the control current. The valve 100 is thus in its control position.

In the housing 103 , a bore 109 is formed for receiving a main piston 110 . At the bore 109 joins un formation of a contact surface 127, a bore 126 with a smaller diameter, in which a piston extension 128 is movably supported. A bore 104 adjoins the bore 126 , in which an armature 136 of the proportional magnet 102 is mounted such that it can be moved back and forth.

The longitudinal bore 109 has bores which run transversely to the longitudinal axis of the valve and form a pump connection 105 , a tank connection 106 and a consumer connection 107 . These connections are also labeled P, T and A.

The main piston 110 has a bore 111 in its left end, in which a piston 112 is moved to and fro. The piston 112 forms a space or a chamber 113 with the housing 103 and also a further space 115 in the piston 110 . The space 115 communicates with a bore 117 of the main piston 110 via a bore 116 . Adjacent to this recess 117 , the main piston 110 forms a first ring web 118 , which in turn is followed by a recess or recess 108 , which is then delimited by a web 119 . The recess 108 forms a tapered section 120 of the main piston 110 . The web 119 is followed by a further recess 121 which defines a space or a chamber 123 . This chamber 123 is connected via an oblique bore 124 with a chamber 137 formed by a bore 129 . The bore 129 extends mainly in the tapering portion 128 of the piston into the actual main piston. A web 122 connects to the recess 121 . The taper part 128 adjoins the web 122 to form a chamber 125 . A plurality of radial bores 133 are formed in the taper part 128 and are connected to the chamber 125 . The tapering part 128 also has radial bores 148 which are connected on the one hand to the chamber 138 and on the other hand to an annular recess which is connected to the bore 105 via a channel 841 . A control piston 130 is arranged to move back and forth in the recess 129 and has a web 131 defining two control edges 145 , 146 , then a control part 134 and then a web 132 , which in turn has a rod part 135 with the armature 136 of the proportional magnet 102 is connected. Web 131 delimits chamber 137 on the one hand and a chamber 138 on the other hand.

The armature 136 of the proportional magnet 102 is under the action of a stronger spring 141 and a weaker spring 142 arranged opposite to it. The spring 141 is arranged in chamber 139 , while the weaker spring 142 is arranged in chamber 140 . A closable opening is provided in the housing 103 in order to be able to insert the armature 136 into the associated bore 104 .

The chambers 113 and 139 and 140 are connected via a channel 144 formed in the housing 103 to the tank connection 106 , so that there is tank pressure in the chambers 113 , 139 , 140 . On the other hand, the pump pressure prevails in the recess 117 and thus also in the chamber 115 . The piston 112 is shown schematically as a spring 147 in the symbol of FIG. 15, but in practice acts as a hydraulic spring. If the piston 112 were replaced by a spring, this would result in the after that there is a pressure dependence. By using the piston 112 , the operation is independent of pressure. If the pressure changes, it changes on the right and left on both sides, whereas with a spring the pressure would only change on one side. Such a dependency on the print quantity would be disadvantageous. The arrangement shown results in a pressure-independent suspension.

In the 3/3-way proportional valve according to the invention, the pressure proportional magnet 102 acts against the small piston 130 , which acts as a 3-way proportional control spool. This control piston 130 works in a mechanical-hydraulic follow-up system in the main stage, ie the valve part 101 , which is also designed as a 3-way valve. An additional electrical position feedback is therefore not necessary for this valve, although it has a highly dynamic effect. The reason for the dynamic lies in the mechanical-hydraulic follow-up system.

It is also possible to design the 3/3-way proportional valve to be directly controlled, in which case the proportional agent 102 would act directly on the main piston (main spool) 130 .

The hydromechanical follow-up system is based on the control edges 145 , 146 of the web 131 , which interact with corresponding control edges, formed by the bores 133 . Furthermore, the printing areas F 1 and F 1 are important, F 2 / F 1 preferably having size 2.

As can be seen in the drawing 14 , the differential valve principle is used in the inventive inventive proportional valve 100 on the one hand and the so-called sequence principle on the other. The valve 100 is designed as a cartridge plug-in valve, but could also be designed as a screw-on valve after attaching appropriate threads and an O-ring.

As far as the function of the valve 100 is concerned, this is driven by a current I supplied to a winding 143 , which preferably comes from a control circuit 33 , as shown in FIG. 5. As mentioned, the main piston 110 is approximately in its central position. Because of the preferably used chopper operation, the main piston 110 swings around this central position. For this reason, the piston 110 is also not shown precisely in its central position in FIG. 14.

If the current I were now increased; armature 136 would move to the left, ie be drawn into magnet 102 against the force of spring 141 . As a result, the pump pressure present in chamber 138 at control edge 146 would reach chamber 125 and act on piston surface F 2 . The other force acting on piston 110 is generated by the pump pressure present in chamber 115 , which acts on surface F 1 . Since, as explained above, the area F 2 is larger than the area F 1 , the main piston 110 also moves to the left as a result of the left movement of the control piston 130 , namely until the passage opened by the control edge 146 is closed again . The main piston 110 is thus practically pulled by the pilot piston 130 . Both pistons follow the same path, i.e. they are hydraulically coupled, and whenever one drives forward, he takes the other with him.

To further explain the function it is now assumed that the current I decreases, as a result of which the ker 136 moves to the right by the force of the spring 141 and thereby also moves the pilot piston 130 to the right, so that the left control edge 145 the in chamber 137 prevailing tank pressure connects to chamber 125 . As a result, the force generated on the surface F 1 is larger than the force generated on the surface F 2 , so that the main piston 110 moves to the right following the pilot piston 130 .

It is a position control of the main piston with mechanical path adjustment. Due to the high power amplification when the two pistons are moved against each other, an almost immediate adjustment of the main stage or a large stiffness speed under the influence of flow forces at the main point enough.

In the following, an inventive complex will be described with reference to FIGS . 16-20 specifically with reference to a circuit or a system for pitching and rolling systems, which moreover generally acts as a control device for supplying and supplying working fluid to or from a hydraulic system Working space with variable volume can be used, using a valve that controls the discharge and the supply of the working fluid. As will be explained in detail below, the locking force of the valves can be adjusted by the proportional solenoids interacting with the closing bodies of the valves.

Fig. 16 shows a circuit or a system which is as shown here in detail, the following ver simplifies the previous embodiments so far represented. On the one hand, one sees a damper system denoted by 2 , which can also be generally referred to as a hydraulic work space with a variable volume. This damper system 2 has in the specific case, when used in a pitching and roll control system, a whole designated with 4 pneumatic, which can be fully or partially load-bearing. In the case of partial wear, an additional mechanical steel spring 5 is connected in parallel to the hydropneumatics 4 . For example, a piston rod 8 , a driving wheel, not shown, is carried by a piston 7 , which forms two piston chambers 11 and 12 in a hydraulic or damping cylinder 6 . The damping cylinder 6 is attached to the vehicle frame. The piston chambers 11 and 12 are connected via a connecting line 13 . The line 13 is also connected via a line 19 to the connection A and also via a line 17 and a damping element 18 to a pressure accumulator 14 , which has a gas space and a liquid space in a known manner. Preferably, a damping element 18 a can be seen in the line 13 between the two piston spaces 11 and 12 .

Valve means 600 are used to connect the connection A of the damping system 2 based on a control signal Y either to a pump P connected to line 21 or to a tank T connected to line 22 .

The control signal Y is supplied by electronics 601 . Electronics 601 generates control signal Y based on information supplied via inputs 602 , 603 , etc.

For example, a sensor can detect when the automobile equipped with the damper system 2 is cornering and supply corresponding information to the electronics 601 . For example, an encoder can also be arranged on the steering wheel, which delivers signals to the electronics. Accelerometers, position sensors, etc., which provide information to the electronics, can also be used. Electronics 601 would then, for example, when driving into a curve, exert a higher pressure on one damper leg, as shown in FIG. 16, than another damper leg. It should be noted here that FIG. 16 shows only one damper leg for use in the automobile, while of course corresponding circuits are also provided for the remaining three wheels.

The valve means 600 are designed here in the form of a pressure reducing valve. The pressure reducing valve in turn is shown here as a slide valve 604 , but the operation of a pressure reducing valve is achieved by the return 605 . A spring is labeled 606 and a proportional magnet is labeled 607 .

Before going into the individual exemplary embodiments of the invention according to FIGS. 17-20, a brief overview of this complex of the invention is first given.

First of all, it should be noted that for pitching and rolling systems, controlled with directional or pressure reducing proportional valves in any case, this corresponds to the holding function control valve with half control current. This is because the inflow and outflow control in one Slider element sits, with the result that then with the so-called "middle position" must be worked. Also are additional electrical sealing valves for the "fail-safe" -Be drive required. This current control with medium current  if the valve or the valve means is not actuated be avoided. It is said to be when not in use System can be operated with "0 current".

The exemplary embodiments shown in FIGS. 17-20 show how the disadvantages just described can be avoided. In principle, this is done by dividing the pressure reducing valve into two separate, specially connected, electrical pressure relief valves. In the case of FIGS. 17 and 18, the pressure relief valves are controlled directly. In Figs. 19 and 20, they are carried out pre-controlled. Furthermore, the embodiments differ according to. Fig. 17 and 18, since by that in Fig., The supply pressure must be constant 17 while the supply pressure in accordance with the circuit. Fig may vary. 18, wherein corresponding or 20 also applies to Fig. 19. In Fig. 19 the supply pressure P must be constant, in Fig. 20 the supply pressure can vary.

In addition to a reduction in the required electrical power when the system is not in use, there is the further advantage that the safety function, that is to say locking when the damper is not moving, is given automatically, since the systems are all closed when de-energized. Another advantage is that the pump pressure in each case by series connection of the proportional valves P 1 and P 2 to be explained are connected in series in all solutions, and this creates the DB function with regard to the supply pressure. A further and fourth advantage is that in the event of Störver in the hydraulic system and keeping the control current constant in the pilot-controlled solutions, higher frequencies can be achieved, since only the hydraulic parts are functioning normally, and the system is only determined by the hydraulic clamping frequency . The main stages H 1 and H 2 still to be explained are meant here.

In short and in principle, the circuit according to. Fig. 17 before that the control signal Y for P 1 or P 2 is inverted more by a V-Umk-Ver. When the pressure in the system increases, the proportional magnet P 1 is excited against the spring 608 and the valve P 1 opens. When the pressure drops, this is done in reverse by opening valve P 2 and closing valve P 1 . In each case, the "de-energized" function is closed.

The same applies to the circuit acc. Fig. 18. Here, however, the proportional valve P 1 is modified, ie if the supply pressure fluctuates, this will remain without influence on the control function of the valve due to the special design. The control areas in both cases relate to diameters (phi) _s .

With the pilot-controlled solution acc. Fig. 19, the systems according to Figs. 17 and 18 designed by additional main stage H 1 and H 2 for larger flow rates. At z. B. Current increase in the proportional magnet P 1 , the preliminary stage V 1 is opened and thereby the control pressure behind the main slide of the main stage H 1 decreases, and the main stage H 1 opens. Pressure is applied to damper A. If the proportional magnet P 2 is excited, the preliminary stage V 2 opens. Characterized the A pressure falls behind the main slide of the main stage H 2, and the main stage H 2 opens to the tank T. The damper pressure "A" decreases. The valve, which is always opposite, is of course closed.

Here there is the advantage in case of disturbance behavior, ie keeping the forces at the preliminary stages constant (I = constant), that the main stages can regulate frequency depending on the mechanical-hydraulic natural frequency. This applies in particular to the main stages H 1 and H 2 according to. Fig. 19 and Fig. 20. In the scarf device acc. Fig. 19, the pressure acts on the precursor A on the control surface of the magnetic step, ie from the rear. This process could be supported by the fact that additional small memories are connected to the chambers behind the main stages. These then determine the hydraulic natural frequency at I = constant at the preliminary stages. However, the dynamic control behavior deteriorates as a result.

These introductory statements can be summarized, that a pressure reduction trim block is provided in particular for a pitching and rolling system, which has two electrically controlled and separate control elements, which are preferably used for proportional control of the damper cylinder or generally a hydraulic work space. These control elements are preferably proportional to the pressure-current. Furthermore, the control elements based on DBE and the PA and AT controls each have a separate valve assigned to them. Since the arrangement is such that no current is used for the valves when the damper is not actuated. Furthermore, the valves lock automatically in the event of a power failure and the damper can self-oscillate in a purely hydropneumatic manner via a memory 14 . The inlet and outlet valve can be controlled di rectly or separately. If the system behaves abnormally, the hydraulic-mechanical main stages can keep the control current of the pre-stages automatically with the mechanical-hydraulic natural frequency. B. regulate pressure. The systems are also connected in series and have an automatic pressure limiting function for the P pressure (supply pressure). In principle, the valves can also be constructed as proportional directional control valves, directly or pilot-controlled (ie a directional control valve is assigned to the P control and a directional control valve is assigned to the AT control).

Fig. 17 shows an embodiment of a pressure reducing block or a control device for supplying and discharging Ar beitsiquid to or from a hydraulic work space with a variable volume. The hydraulic workspace with variable volume is here again in the special application as a damper system 2 with a connection A Darge. The system shown in FIG. 17 can be used especially with pitching and rolling systems, in which case the circuit according to FIG. 17 would have to be provided in a corresponding manner for the three other wheels, with only the electronics also being used to supply the other systems could. The same applies to the exemplary embodiments according to Fig. 18-20 .

For the inflow and outflow of working fluid (especially hydraulic oil) is gem. Fig. 17 seen a pressure reducing block 610 before, which has separate valves P 1 and P 2 for the inflow and outflow of working fluid. Control electronics 611 has several inputs, e.g. B. 602 and 603 similar to FIG. 16 and provides a control signal Y and an inverted control signal Y to the pressure reducing block 610 via control lines 612 , 613 . An inverter V-Umk generates the reverse control signal.

One valve P 1 is preferably a proportional pressure limiting valve with a closing element or closing body 614 . The closing element 614 has a closing cone 615 , which is pressed against a seat 616 in the valve housing 617 by the spring 608 already mentioned. A ring arm 618 and a control arm 619 are also formed in the valve housing 617 . The ring arm 618 is connected to the connection A. The diameter of the control room 619 is denoted by (phi) _s .

In contrast to the control chamber 619 , a spring chamber 620 is formed in the housing 617 , in which the spring 608 already mentioned is seated. Furthermore, the connection A is connected to the spring chamber 620 via a line 21 . A proportional magnet 622 can, due to the control signal and the electronics 611 ent, either press the closing element 614 more strongly against the seat 616 , or exert a force on the closing element 614 against the force of the spring 608 . Control room 619 is connected to port P.

The task of the proportional pressure relief valve P 1 is, if necessary, to supply control liquid quantity above "A" in order to keep the working pressure in connection "A" and thus in damper 2 at a certain value. This is done by the control edge formed by the seat 616 in cooperation with the closing cone 615 .

The proportional pressure relief valve P 2 , which is still present, serves to keep the pressure in the connection or the line A at a certain value by letting off the amount of working fluid. For this purpose, a closing element 623 is in turn hen, which is biased by a spring 624 with a closing cone 625 against a seat 626 forming control edges. A control chamber 628 having a smaller diameter is connected to the connection A and an annular chamber 627 formed in the housing 617 by the seat 626 and separated from the control chamber 628 is connected to the tank connection T. Furthermore, a spring chamber 629 , which has a larger diameter than the control chamber 628 , is connected to the tank T.

As with valve P 1, the proportional magnet 622 , here with valve P 2, the proportional magnet 630 serves to set the locking force due to the closing elements 614 and 623 .

Fig. 18 shows the omission of the damper system 2 or, more generally speaking, a hydraulic work space with variable volume, another design of a pressure reducing block 635 , which differs from the pressure reducing block 610 primarily in that the supply pressure P is not constant here must, but can vary.

The valve P 2 is designed here as in FIG. 17, so that this valve need not be discussed in more detail here. All recently, the diameter of the control chamber 628 is designated with (phi) _s here.

The pressure relief valve P 1 in FIG. 18 in turn has a seat 616 forming a control edge and a proportional magnet 622 . An expanding bore is provided in the housing 617 , in which a closing element 636 is arranged such that it can be moved back and forth. The closing element 636 is pressure-compensated and has a control cone 641 which is pressed against the seat 616 by a spring 640 . Further, a stationary with port A in communication space 637, a smaller diameter owning space 638 and the diameter (phi) _s owning space 639 is formed. The room 638 is connected to the pump connection P and the room 639 is connected to the tank connection T.

The circuit of FIG. 19 corresponds to the circuit shown. Fig. 17, with the exception that here two piloted Druckbegren tion valves P 1 and P 2 are used. When the pilot-operated pressure relief valve P 1, the valve V 1 corresponds to the valve P 1 of FIG. 17 and a pilot-operated pressure relief valve P 2 corresponds to the valve V 2 the valve P 2 of FIG. 17. In that regard and also with regard to the electronics 611 can be referenced to the preceding description to get expelled. Only the two main valves H 1 and H 2 have to be described.

The main valve H 1 is formed by a different diameter bore in the housing 617 . A main piston 650 is reciprocally arranged in this longitudinal bore and can be pressed by a spring 654 with its closing bevel 642 against a seat 651 provided in the housing, the latter forming a control edge. A control space 653 communicates with the pump port P, and an annulus 652 communicates with the port A. At the front of the main piston 650 , a throttle 655 is provided, which connect the control chamber 653 to a piston chamber 656 , which in turn is connected to the control chamber 619 of the pre-control valve V 1 . The main valve H 2 is similar to the main valve H 1 and has a main piston 750 with throttle 655 , a piston chamber 756 , a spring 754 , an annular space 752 , a control chamber 753 and between them a seat or control edge 751 for working together with the bevel 742 . The control chamber 753 is connected to the connection A, while the annular chamber 752 is connected to the tank connection T. Overall, the pressure reduction block formed from the two pilot-controlled proportional pressure relief valves P 1 and P 2 is designated 660 .

In Fig. 20, a pressure reducing block 670 is shown, which has a pilot-controlled pressure relief valve P 1 and a pilot-controlled pressure relief valve P 2 . The pilot operated pressure relief valve P 2 acc. Fig. 20 corresponds to the pre-controlled pressure relief valve P 2 of FIG. 19, so that a description can be omitted here.

As far as the pilot operated pressure relief valve P 1 is concerned, it consists of a pilot valve V 1 and a main valve H 1 . The pilot valve V 1 of FIG. 20 corresponds to the pilot valve P 1 of FIG. 18, so that a description can be omitted here. The main valve H 1 of FIG. 20 differs from the main valve H 1 of FIG. 19 in that H 1 in FIG. 20 is pressure-compensated.

The main valve H 1 in FIG. 20 has a main piston 671 , specifically to form a piston chamber 656 in which a spring 678 is arranged. The piston chamber 656 communicates with the control chamber 637 of the pilot valve V 1 . The main piston 671 also forms, together with the bore arranged in the housing 617 , an annular space 672 and a control space 680 . A spring 673 , which is stronger than the spring 678, is arranged in the control chamber 680 . The main piston forms a bevel 674 , which cooperates with a seat 675 formed in the housing 617 and thus forms a control edge. The control chamber 680 is connected to the piston chamber 656 via a throttle 655 .

Claims (49)

1. Control system for the stabilization of a vehicle, in particular using the damper systems of the vehicle in order, characterized in that
that each wheel is assigned a damper system ( 2 ), that each damper system ( 2 ) has a directional control valve ( 44 to 77 ),
and a safety valve device ensuring further operation of the system is assigned when an error occurs. 2. System according to claim 1, characterized in that the Safety valve device the directional control valve function with takes over, the safety valve device from two spring-loaded seat valves is formed, of which that one seat valve connects to the tank and the other Seat valve controls the connection to the pressure medium source and the closing force of the poppet valves by one Magnetic force can also be determined. 3. Control system or device for supplying and removing Working fluid to or from a hydraulic ar workspace with variable volume using a the discharge and one the supply of the working fluid speed controlling valve, characterized in that the Locking force of the valves with the closing bodies of the Proportional proportional solenoids adjustable is. 4. Control system for the stabilization of a vehicle, in particular a motor vehicle, in particular using damper systems associated with the use of the wheels of the vehicle, characterized in that
that each wheel is assigned a damper system ( 2 ), that each damper system ( 2 ) is assigned a directional control valve ( 44-47 ), and
that safety valves are provided which ensure the continued operation of the system if an error occurs. 5. System according to claim 4, characterized in that the Directional control valves designed in pilot-controlled design are. 6. System according to claim 4 or 5, characterized in that each directional control valve as a mechanical-hydraulic consequence valve is constructed. 7. System according to one or more of the preceding claims che, characterized in that the actual regulation the route via electrical sensors such as pressure, displacement, Force acceleration or the like takes place. 8. System according to one or more of the preceding claims che, characterized in that each damper system, before preferably at least one damper cylinder and one has hydropneumatic memory, and that each damper Remote system individually, especially via pilot-controlled shooting Over or seat valves can be shut off, the pilot tion is carried out especially centrally. 9. System according to one or more of the preceding claims, characterized in that the safety valve device is preferably formed by seat valves ( 51 , 52 , 55 , 56 ). 10. The system according to one or more of the preceding claims, characterized in that the damper systems assigned to an axis can be connected to one another via a cross check valve ( 48 , 49 ). 11. System according to one or more of the preceding claims, characterized in that the transverse check valves ( 48 , 49 ) have throttles integrated. 12. System according to claim 11, characterized in that the cross-blocking valves ( 48 , 49 ) are controlled by the same pilot control ( 50 ) as the seat valves ( 51 , 52 , 55 , 56 ). 13. System according to one or more of the preceding Ansprü surface, characterized in that the Proportionalwegeven tile ( 44-47 ) are formed in an integrated design, where the proportional magnet and the valve are housed in a housing ( 103 ). 14. System according to one or more of the preceding claims, characterized in that each proportional directional valve ( 44-47 ) is designed as a cartridge valve, either as an inserted cartridge (as shown in FIG. 14) or as a screwed cartridge with thread and O-ring. 15. System according to one or more of the preceding claims, characterized in that the valves ( 51 , 52 , 55 , 56 ) required to implement operational safety are actuated directly electrically and, for example, not via the central pressure. 16. System according to one or more of the preceding claims che, characterized in that the directional control valve (Pro  proportional directional valve) with a mechanical-hydraulic Follower circuit works so that no additional electrical Sensor is necessary. 17. System according to one or more of the preceding claims che, characterized in that each path is proportional valve is open when de-energized. 18. System according to one or more of the preceding claims che, characterized in that the safety valves preferably as seat valves, especially for reasons of Pollution protection, are executed and that the Si safety valves are designed to be de-energized and leak-free. 19. System according to one or more of the preceding claims che, characterized in that the damper system part is bearing or fully bearing. 20. System according to one or more of the preceding claims che, characterized in that the damper system has hydropneumatic memory and that to the damper only one control line. 21. System according to one or more of the preceding claims, characterized in that a further variable throttle is connected between the upper and lower damper chamber ( 11 , 12 ). 22. System according to one or more of the preceding claims, characterized in that each damper system ( 2 ) is assigned a control circuit ( 33 ), which is preferably connected to the damper system via an associated pressure sensor ( 31 ) and the proportional magnet ( 41 ) of the associated directional proportional valve ( 30 ), where if the control current fails, a spring ( 42 ) brings the directional proportional valve ( 30 ) into a position where the pump is blocked and the damper system ( 2 ) is connected to the tank (T). 23. System according to one or more of the preceding claims, characterized in that the path proportional valve ( 30 ) is operated in chopper mode. 24. System according to one or more of the preceding claims, characterized in that at least one safety valve ( 50 ) connected to the pump connection (P) and the tank connection (T) delivers a control pressure when excited by a current for as long as the a proper operation current is supplied to the solenoid of the safety valve ( 50 ), while when this power fails, a spring moves the safety valve ( 50 ) to a position where no pilot pressure is supplied and that the pilot pressure is preferably used to actuate all of them downstream safety valves, in particular the switching valves ( 51 , 52 , 55 , 56 and 48 and 49 ) is used. 25. System according to one or more of the preceding claims, characterized in that the safety valve ( 50 ) is a 3/2-way valve. 26. System according to one or more of the preceding claims, characterized in that each of the proportional directional control valve ( 44-47 ) is assigned a 2/2-way seat valve ( 51 , 52 , 55 , 56 ) which, in the event of a fault, connects the connection between the interrupts the respective proportional directional control valve and the associated damper system ( 2 ). 27. System according to one or more of the preceding Ansprü surface, characterized in that in each case a transverse locking valve of the front axle and one of the rear axle is assigned, and that, in addition, shut-off valves separate the damping systems of the left and right wheels from each other, while in the event of a malfunction Connection between the respective damper systems, preferably via a throttle ( 480 , 490 ) is made. 28. System according to one or more of the preceding claims, characterized in that all the valves are arranged in a block ( 43 ). 29. System according to one or more of the preceding claims, characterized in that the valves cooperating with the front axle are arranged in a valve block ( 80 ) and the valves cooperating with the rear axle are arranged in a valve block ( 81 ) via lines ( 167 , 168 ) and a control line ( 172 ) are connected, the safety valve ( 50 ) to be referred to as a pre-stage valve being arranged in one block. 30. System according to one or more of the preceding claims, characterized in that the pressure supply can be shut off by a common valve ( 83 ), that the pilot control of this valve ( 83 ) in turn is designed as a 3/2-way pilot valve safety valve follows and that the tank line can be interrupted in the event of a malfunction by a second two-way valve ( 84 ), the valves ( 83 , 84 ) being controlled by the safety valve ( 50 ) and also in the event of a malfunction which is characterized by a power failure , The damping systems ( 2 ) at the connections (A 1- A 4 ) are each connected via the so-called "fail safe" position of the 3/3 proportional directional valves ( 44-47 ). 31. System according to one or more of the preceding claims  che, characterized in that the pump and tankab switching valves formed by a 4/2-way switching valve are. 32. System according to one or more of the preceding claims che, characterized in that the cross shut-off valves a single 4/2-way switching valve are combined. 33. System according to one or more of the preceding Ansprü surface, characterized in that in a 4/2-way shut-off valve ( 93 , 94 ) the damper systems ( 2 ) of the Vorderach se associated check valves as well as the associated cross check valve are combined, wherein the control of the two 4/2-way shut-off valves ( 93 , 94 ) by a common 3/2-way pilot valve (safety valve) ( 50 ). 34. System according to one or more of the preceding claims, characterized in that in each case a 4/2-way shut-off valve ( 93 ) together with the two proportional directional control valves ( 44 , 45 ) assigned to the front axle and the control valve ( 50 ) in a valve block ( 164 ) are arranged, while in a further valve block ( 165 ) assigned to the rear axle, the other 4/2-way shut-off valve ( 94 ) and two proportional directional control valves ( 46 , 47 ) are arranged. 35. Proportional directional control valve with a housing in which a main piston ( 110 ) is arranged so that it can move back and forth, and wherein a pilot piston ( 130 ) is arranged so that it can be moved back and forth, namely coupled to an armature ( 136 ) of a proportional magnet ( 102 ). 36. proportional directional control valve according to claim 35, characterized in that in the main piston ( 110 ) opposite the pilot piston ( 130 ) a piston ( 112 ) is arranged to form a piston chamber ( 115 ) which can be connected to the pump pressure. 37. Proportional directional control valve according to one of claims 35 and 36, characterized in that the pump pressure is supplied to the pilot piston ( 130 ) and can act via control edges ( 145 , 146 ) on a surface (F 2 ) of the main piston which is larger than one Area (F 1 ) on which the pump pressure acts in the chamber ( 115 ). 38. Control system for the supply and discharge of working fluid to or from a hydraulic work space ( 2 ) with variable volume using a valve which controls the discharge and supply of the working fluid, characterized in that the locking force of the valves (P 1 , P 2 ) of proportional magnets ( 622 , 630 ) interacting with the closing elements ( 614 , 623 ) of the valves. 39. System according to one or more of the preceding claims, characterized in that the hydraulic working space is formed by a damper system ( 2 ) of a vehicle wheel. 40. Control system for controlling the supply and discharge of Ar working fluid to a hydraulic work space below Use of electromagnetically controlled valve means, characterized, that the valve means are designed so that these at Zero current, i.e. in the case of non-use or in the case of Power outages are closed and so a "fail Enable safe "operation. 41. Control system for controlling the supply and discharge of Ar working fluid to a hydraulic work space, thereby characterized in that the valve means in a valve for the Inflow and are separated in a valve for the drain, so that inflow and outflow control is not on a slide element to sit. 42. Control system for controlling the supply and discharge of Ar working fluid to a hydraulic work space, thereby characterized in that using two pressure limits relief valves, one for the inflow and one for the outflow a pressure reducing valve preferably in the form of a  Pressure reducing block is formed. 43. Control system according to one of the preceding claims, characterized in that the pressure relief valve ( 1 ) responsible for the inflow is pressure-compensated. 44. Control system according to one of the preceding claims, characterized in that the two pressure relief valves as pilot operated proportional pressure relief valves are trained. 45. Control system according to one of the preceding claims, characterized in that the valve responsible for the inflow (P 1 ) in both its preliminary stage (V 1 ) and in its main stage (H 1 ) is pressure-compensated, while the one responsible for the outflow Valve (P 2 ) is piloted or not piloted. 46. Control system according to one of the preceding claims, characterized in that by two electrically controlled and separate control or closing elements the proportional Control of a hydraulic work space with changeable Volume, especially a damping cylinder. 47. Control system according to one of the preceding claims, characterized in that the control elements work on a DBE basis and that the PA and AT controls each have a separate valve (P 1 , P 2 ) assigned to them. 48. Control system according to one of the preceding claims, characterized in that the inflow and outflow valve (P 1 , P 2 ) are controlled separately or directly in a pilot-controlled manner. 49. Control system according to one of the preceding claims, characterized in that the inlet and outlet valve as  Proportional directional control valve directly controlled or pilot operated are built up, d. H. the P control is a one-way valve and the other control valve is assigned to the AT control.