EP3258116B1 - Hydraulic module with pressure-controlled 2-way flow control valve - Google Patents

Description

The present invention relates to a hydraulic module according to the preamble of independent claim 1 and in particular to a hydraulic module with a pressure-controlled 2-way flow control valve.

In demanding hydraulic circuits, e.g. In a crane, a concrete placing boom, a forklift and other load lifting and manipulating devices, proportional directional spools with a 2-way flow control valve are generally used to enable the simultaneous actuation of several consumers and / or to set a travel speed on one consumer. For example, in practice it is often necessary to control several consumers independently of the load pressure.

According to pages 104 to 113 of the HAWE product range 2015, a proportional directional spool valve type PSL with connection blocks and an add-on block is known. Regarding Fig. 1a is schematically an exemplary known hydraulic circuit with two proportional directional spool valves of the type PSL, in Fig. 1a denoted by the reference numerals PS1, PS2, and a suitable connection block for a constant pump 1 for operating two consumers V1, V2. A supply pressure P output by the constant pump 1 is supplied through a supply line 6 to a plurality of consumers V1, V2, for example hydraulic cylinders, shown in a highly schematic manner via the respective proportional directional spool valves PS1, PS2 in order to drive the consumers V1, V2. The inflow upstream of the proportional directional spool valves PS1, PS2 is regulated in each case by a pressure-controlled 2-way flow control valve 41, 42, which is upstream of the corresponding proportional directional spool valve PS1, PS2 (ie, upstream of the corresponding proportional directional spool valve PS1, PS2 ) is arranged. If at least one of the consumers V1, V2 is operated during operation, the associated proportional directional spool valve PS1, PS2 is deflected upwards or downwards from the blocking state shown, depending on whether a connection A1, A2 connected to the corresponding consumer V1, V2 or B1, B2 to be connected to the supply line 6. Via the stroke of the deflection, a volume flow to the respective consumer V1, V2 is predetermined by the proportional directional spool valves PS1, PS2, for example in order to set a speed at the corresponding consumer V1, V2.

Via a corresponding LS line LS1, LS2 (in Fig. 1 shown in dashed lines) a load pressure falling downstream of the corresponding proportional directional spool valve PS1, PS2 is applied the associated 2-way flow control valve 41, 42 reported. Furthermore, changeover valves 2 ensure that the highest load pressure from the load pressures reported by the LS lines LS1, LS2 (corresponds to the load pressures dropping at the consumers V1, V2) is reported to a circulation controller 8 of the constant pump system.

The load pressure reported by the LS line LS1 or LS2 to the 2-way flow control valve 41 or 42 is applied to the 2-way flow control valve 41 or 42 in the up-control direction to support the biasing force of the biasing spring. Furthermore, each 2-way flow control valve 41, 42 is also applied with a pressure signal tapped on the output side of the respective 2-way flow control valve 41, 42 in the closed control direction (i.e. counteracting the bias) of the respective 2-way flow control valve 41, 42. Each of the 2-way flow control valves 41, 42 is biased in the open control direction by a biasing spring, so that the 2-way flow control valves 41, 42 are opened in the idle state.

In the equilibrium position there is consequently between the tapped LS pressure and a pressure present in the supply line (in Fig. 1a tapped after the 2-way flow control valve 41, 42) a certain pressure difference. As a result, changes in the volume flow are regulated to a constant value, whereby prestressing springs with a small spring constant or flat spring characteristic are usually used. Each of the 2-way flow control valves 41, 42 thus regulates a volume flow through the corresponding proportional directional spool valve PS1, PS2 to a constant value regardless of the load. In other words, if the volume flow occurring behind the proportional directional spool valve PS1 or PS2 drops during the operation of the consumer V1 or V2, the pressure difference between the pressure falling behind the 2-way flow control valve 41 or 42 also drops (reported as "p _A ") and the load pressure falling behind the proportional directional spool valve (which is reported as "p _LS " via the LS line LS1 or LS2 to the 2-way flow control valve 41 or 42), so that a Control piston (not shown) in the 2-way flow control valve 41 or 42 moves along the open control direction. The consequence is that the control piston in the 2-way flow control valve 41 or 42 again achieves a balance of forces, albeit with a larger throttle cross section in the 2-way flow control valve 41 or 42. This reduces the volume flow through the pressure difference (p _A - p _LS ) in the equilibrium of forces with the preload spring compensated to the desired extent.

As a result, the volume flow to the consumer and the pressure difference between the pressure provided by the constant pump 1 and the pressure in the load circuit to the consumer are regulated to a constant value.

On the other hand, if the pressure difference (p _A - p _LS ) at the proportional directional spool PS1 or PS2 increases, which corresponds to an increase in the volume flow, the 2-way flow control valve is controlled in the closed-control direction until a new force balance is established. In the 2-way flow control valve, a control piston (not shown) moves in the closed control direction and a throttle cross-section in the 2-way flow control valve 41 or 42 decreases. As the throttle cross-section decreases, the volume flow and the pressure difference (p _A - p _LS ) again (which counteracts the initial increase) and an equilibrium of forces is established in which the increase in the volume flow and the pressure difference are compensated.

In Fig. 1b is the resulting characteristic of the 2-way flow control valve (cf. 41, 42 in Fig. 1a ) and the proportional directional spool (cf. PS1, PS2 in Fig. 1a ) is shown schematically. Here, a volume flow Q is plotted along the abscissa in arbitrary units against a pressure difference Δp (corresponds to the pressure loss across the 2-way flow control valve and the proportional directional spool valve) along the ordinate in arbitrary units.

The characteristic curve has three sections: in section a1 the 2-way flow control valve is fully open and the characteristic curve follows the dynamic pressure characteristic curve (the dynamic pressure is proportional to the flow velocity and the dynamic pressure curve shows that the pressure loss is proportional to Q ² ). A section a2 of the characteristic curve represents the transition between the dynamic pressure characteristic curve and a desired control of the 2-way flow control valve, the control behavior of the 2-way flow control valve depending on the mechanical properties of the preload spring and the reported pressure signals via the LS line and in the tap directly after the 2-way flow control valve. The characteristic curve deviates in section a2 from the dynamic pressure characteristic and even small changes in Δp lead to relatively large (in comparison to section a3) changes in the volume flow, so that no stable control is possible here. In a section a3, on the other hand, the control functions in a stable manner and the volume flow can be kept constant, independently of the load pressure and independent of pressure fluctuations, at a value Q ₀ , which is essentially predetermined by the proportional directional spool and means, for example, a desired speed at the consumer. A change in the spool position of the proportional directional spool valve leads to a different volume flow, which is to be kept pressure-dependent by the 2-way flow control valve.

The pressure losses represented by the characteristic curve lead to a power loss of Δp * Q, which dissipates into the heating of a hydraulic medium. In particular, the course of the characteristic curve in section a2 deviates from the course in section a1 and the pressure losses in section a2 are greater than in section a1. Section a2 is energetically unfavorable compared to section a1.

There is also a problem in section a2 that pressure fluctuations in section a2 are insufficiently damped due to the steeper course in section a2 compared to section a1, and there is a risk that a system consisting of a 2-way flow control valve and a series-connected valve Can swing up the controller in the inlet section or on the variable displacement pump and thus have a negative influence on a stable inlet in section a3,

A hydraulic module of this type is from the publication DE 4420459 already known.

In view of the situation described above, it is desirable to keep energy losses as low as possible and to enable control operation to be as stable as possible even at low pressures and / or small volume flows.

For example, there is the task of providing a 2-way flow control valve and a valve arrangement with a corresponding 2-way flow control valve, the volume flow control being stabilized at the operating points, especially in interaction with other hydraulic controllers, and / or a stable volume flow control above all is made possible in lower pressure difference ranges.

The above objects and problems are solved in a first aspect of the invention by a hydraulic module with a pressure-controlled 2-way flow control valve. In illustrative embodiments, the pressure-controlled 2-way flow control valve is arranged in a supply line of the hydraulic module and is biased in the open control direction by a first biasing element. Downstream or upstream of the pressure-controlled 2-way flow control valve, a first pressure signal is tapped in the supply line and the first pressure signal can be applied to the pressure-controlled 2-way flow control valve in the closed-control direction or open-control direction via a first control line. A control device is also arranged in the first control line for pressure control of the pressure-controlled 2-way flow control valve. The control device is configured so that application of the first pressure signal to the pressure-controlled 2-way flow control valve is blocked in a first control state. In a second control state, the first pressure signal can be applied by the control device to the pressure-controlled 2-way flow control valve in the closed control direction.

In the hydraulic module defined above, the pressure-controlled 2-way flow control valve is controlled in such a way that a deviation of a pressure loss or differential pressure across the pressure-controlled 2-way flow control valve from a course according to a dynamic pressure characteristic curve is determined by the control device and thus energy losses can be kept low. and the entry into stable control mode in the hydraulic module can be reliably provided by the pressure-controlled 2-way flow control valve.

In an illustrative embodiment of the hydraulic module described above, the first control line upstream of the pressure-controlled 2-way flow control valve can be tapped in the supply line. In this case, the hydraulic module can further comprise a first signal line, which is branched upstream of the control device in the first control line, the control device being switchable to the first or second control state depending on a pressure signal tapped by the first signal line.

In another illustrative embodiment of the hydraulic module according to the first aspect above, the first control line upstream of the pressure-controlled 2-way flow control valve can be tapped in the supply line. Here, the hydraulic module can further comprise a second control line, which is connected to the supply line upstream of the pressure-controlled 2-way flow control valve. The control device can be switched to the second control state depending on a second pressure signal tapped by the second control line.

In a further illustrative embodiment, the control device can comprise a pressure-controlled 2-way valve, which is actuated by a second biasing element (for example in the closed control direction if the first pressure signal is applied in the closed control direction; otherwise in the open control direction if the first pressure signal is in the open position Control direction is applied) is biased. The pressure-controlled 2-way valve is controlled in the closed control direction or open-control direction in the first control state, while it is open-controlled or closed-control in the second control state, so that the first pressure signal depends on the control state of the control device to the pressure-controlled 2 -Way flow control valve can be applied or can be blocked.

In a more descriptive embodiment of this, the second pressure signal can be applied to the pressure-controlled 2-way valve in the closed-control direction via the second control line. Thereby a circuit of the control device designed as a 2-way valve is implemented in a simple and reliable manner.

In an illustrative example of various embodiments, the pressure-controlled 2-way flow control valve is completely open-controlled in the first control state of the control device if the first pressure signal is tapped downstream of the 2-way flow control valve. Otherwise, the pressure-controlled 2-way flow control valve can be completely open-controlled in the second control state of the control device if the first pressure signal is tapped upstream of the 2-way flow control valve. This enables an energetically advantageous operation in the range of low pressures to be provided, since pressure losses in the range of low pressures can be kept low.

In a further illustrative embodiment, the hydraulic module can further comprise a third control line, which is connected downstream of the pressure-controlled 2-way flow control valve to the supply line, a third pressure signal being applied to the pressure-controlled 2-way flow control valve in the open-control direction via the third control line can be. In a special example, the third control line can be connected to the supply line downstream of a proportional slide valve arranged downstream in the supply line or in front of a consumer in order to tap a pressure signal corresponding to a consumer pressure via the third control line, pressure control of the 2-way flow control valve taking into account a Pressure downstream of the 2-way flow control valve, e.g. consumer pressure.

In a more descriptive embodiment, the hydraulic module can further comprise a fourth control line, which is connected to the third control line, wherein the third pressure signal can be applied to the control device via the fourth control line. The control device can thus be switched to the first control state depending on the third pressure signal. This allows regulation depending on the third pressure signal.

In a further illustrative embodiment, the third pressure signal can be applied to the pressure-controlled 2-way flow control valve in the closed control direction in the first control state of the control device. As a result, the control device can advantageously implement a control of the 2-way flow control valve that is dependent on the third pressure signal.

In a further illustrative embodiment, the hydraulic module can further comprise a proportional directional spool, which is arranged in the supply line downstream of the pressure-controlled 2-way flow control valve.

In a more illustrative embodiment, the first pressure signal can be tapped upstream of the proportional directional spool. Furthermore, the third pressure signal can be tapped downstream of the proportional directional spool. As a result, the volume flow can be regulated taking into account the pressure loss across the proportional directional spool valve in order to constantly regulate the volume flow through the proportional directional spool valve regardless of the pressure loss.

In a further illustrative embodiment, the 2-way flow control valve and the control device can be integrated in a valve block. This makes it easy to install the hydraulic module in existing hydraulic systems and / or replace it if necessary.

In a further illustrative embodiment, the control device can comprise an adjustable prestressing element, by means of which the control device is prestressed in the first control state. As a result, the time of switching between the first and second control states of the control device can be set in a user-dependent manner.

In a further illustrative embodiment, the control device can only have the first and second control states as two discrete switching positions. This represents a simple structure for a control device.

In a further aspect, a hydraulic module system is provided, comprising at least two hydraulic modules, only one of the at least two hydraulic modules being designed according to the hydraulic module according to the aspect described above. This is an advantageous solution for hydraulic systems with multiple consumers.

Fig. 1a

schematisch eine bekannte Ventilanordnung mit 2-Wege-Stromregelventilen;

Fig. 1b

die Kernlinie eines bekannten Stromregelventils schematisch darstellt;

Fig. 2

schematisch ein Hydraulikmodul gemäß einer Ausführungsform der vorliegenden Erfindung darstellt;

Fig. 3

schematisch eine Kennlinie des Hydraulikmoduls aus Fig. 2 gemäß einer Ausführungsform der vorliegenden Erfindung darstellt;

Fig. 4

schematisch ein Hydraulikmodul gemäß einer speziellen Ausführungsform der vorliegenden Erfindung darstellt;

Fig. 5

schematisch ein Hydraulikmodul gemäß einer anderen Ausführungsform der vorliegenden Erfindung darstellt;

Fig. 6

schematisch ein Hydraulikmodul gemäß einer speziellen Ausgestaltung zu der in Fig. 5 dargestellten anderen Ausführungsform darstellt; und

Fig. 7

schematisch Kennlinien eines Hydraulikmoduls gemäß verschiedener Ausführungsformen der vorliegenden Erfindung darstellt;

Further advantageous embodiments of the present invention are described below with reference to the following figures, in which:

Fig. 1a

schematically a known valve assembly with 2-way flow control valves;

Fig. 1b

schematically represents the core line of a known flow control valve;

Fig. 2

schematically illustrates a hydraulic module according to an embodiment of the present invention;

Fig. 3

schematically a characteristic of the hydraulic module Fig. 2 according to an embodiment of the present invention;

Fig. 4

schematically illustrates a hydraulic module according to a particular embodiment of the present invention;

Fig. 5

schematically illustrates a hydraulic module according to another embodiment of the present invention;

Fig. 6

schematically a hydraulic module according to a special embodiment to that in Fig. 5 illustrated other embodiment; and

Fig. 7

schematically illustrates characteristics of a hydraulic module according to various embodiments of the present invention;

Various aspects and refinements of the present invention are described in greater detail below with reference to the accompanying figures.

Fig. 2 14 schematically shows a hydraulic module 100 according to some illustrative embodiments of the invention. The hydraulic module 100 can, for example, be integrated in a valve block or alternatively can be composed of different sub-modules.

According to the illustrative embodiment shown, the hydraulic module 100 comprises a supply line 105 which is connected to a supply unit, for example a constant pump (such as in FIG Fig. 1a is shown) or a variable displacement pump, in order to supply the hydraulic module 100 with a hydraulic medium, for example a hydraulic oil or the like. The supply line 105 is kept at a supply pressure P.

In illustrative embodiments, the hydraulic module 100 has a proportional directional spool 110 arranged in the supply line 105, through which the supply line 105 can be connected to one of two consumer lines A, B. A hydraulic consumer (not shown), for example a hydraulic cylinder, can be connected to the consumer lines A, B.

Furthermore, as shown in Fig. 2 a pressure-controlled 2-way flow control valve 120 is arranged upstream of the proportional directional spool valve 110 in the supply line 105. In the hydraulic module 100, a tank line (not shown) is also shown, which is connected to a tank connection R and can be coupled to a reservoir (not shown).

The proportional spool 110 can be controlled electromagnetically in order to set a suitable stroke of the proportional spool 110, so that one of the three switch positions shown is adopted. In the switching position shown, the proportional directional spool valve 110 blocks a passage through the supply line 105. In the other two switching positions of the proportional directional spool valve 110, either the consumer line B is connected to the supply line 105 (upper switching position), or the consumer line A becomes the supply line 105 connected (lower switching position). In the upper and lower switching position, a volume flow from the supply line 105 into one of the consumer lines A, B proportional to the stroke of the proportional directional spool valve 110 is set, for example, via a control edge (not shown) in the proportional directional spool valve 110. In this way, for example, a desired speed can be set on a hydraulic consumer (not shown), for example a hydraulic cylinder. As above regarding the Fig. 1a has been shown, the pressure-controlled 2-way flow control valve 120 permits pressure-independent control of the volume flow to the consumer to a constant value, as specified by the proportional directional spool valve 110.

Opposite the in Fig. 1a 2-way flow control valves 41, 42 shown, the 2-way flow control valve 120 is pressure-controlled via a control device 130. The control device is arranged in a first control line 123, which taps a first pressure signal downstream of the 2-way flow control valve 120, which can optionally be applied by the control device 130 in the closed control direction of the 2-way flow control valve 120 or in the illustrated state of the control device 130 is blocked and therefore cannot be applied to the 2-way flow control valve in the closed control direction. The control device 130 can, according to illustrative embodiments, as in FIG Fig. 2 is shown as an example, designed as a 2-way valve with two discrete switching positions. In a first control state 132 of the control device 130, application of the first pressure signal via the first control line 123 in the closed control direction to the 2-way flow control valve 120 is blocked. In a second control state 134 of the control device 130, the first pressure signal tapped by the first control line 123 can be applied to the 2-way flow control valve 120 in the closed control direction.

According to illustrative embodiments, the control device 130 can be controlled as a function of a signal 136. In some illustrative examples, the signal 136 represent a hydraulic control signal. In alternative examples, the signal 136 can represent an electromagnetic control signal (for example an electrical signal for actuating an electromagnet, which can optionally set the first control state 132 or the second control state 134). In some specific examples herein, a pressure sensor may be disposed in the supply line 105 upstream of the 2-way flow control valve 120 and / or downstream of the 2-way flow control valve 120 and / or downstream of the proportional directional spool valve 110, so that control of the control device 130 into a desired control state of the first and second control states 132, 134 depending on the at least one tapped pressure signal.

Regarding Fig. 2 the 2-way flow control valve 120 will now be described in more detail. The 2-way flow control valve 120 is prestressed in the open control direction by means of a prestressing element 122, for example a mechanical spring element. According to specific illustrative examples herein, the 2-way flow control valve may be fully open only by the action of the biasing member 122 in the up-control direction. Downstream of the 2-way flow control valve, for example downstream of the proportional directional spool valve 110, an LS pressure signal is applied to the 2-way flow control valve 120 in the up-control direction by means of an LS line LS1 in support of the biasing by the biasing element 122. A throttle element can be provided in the LS line LS1 in order to set a desired throttling in the LS line LS1.

In illustrative embodiments, a first pressure signal that is tapped in the supply line downstream of the 2-way flow control valve and is applied to the 2-way flow control valve in the closed control direction when the control device 130 is switched to the second control state 134 compared to an LS pressure and depending on the preload by the biasing element 122, a volume flow through the 2-way flow control valve 120 and the proportional directional spool valve 110 can be set on the basis of the pressure difference between the first pressure signal and the LS pressure. If, on the other hand, the control device 130 is switched to the first control state 132, the first pressure signal is applied to the 2-way flow control valve 120 in the closed control direction, in particular only the biasing element 122 and possibly the LS pressure signal act via the LS line LS1 in Up-control direction Up-controlling to the 2-way flow control valve 120. For example, the 2-way flow control valve can be completely open-controlled in the first control state 132. A volume flow through the 2-way flow control valve 120 and the proportional directional spool valve 110 in the first control state 132 is thus set to a maximum corresponding to the stroke of the proportional directional spool valve 110. For a given control edge cross-section in the proportional directional spool 110, which can be set, for example, by a suitable setting of a control stroke in the proportional directional spool 110, there is no regulating effect by the 2-way flow control valve 120, as long as the control device 130 is in the first control state 132. The volume flow through the proportional directional spool valve 110 thus essentially follows a dynamic pressure characteristic curve, ie the pressure loss across the proportional directional spool valve 110 and the 2-way flow control valve 130 is essentially proportional to the square of the volume flow rate and indirectly proportional to the control cross section in the proportional directional spool valve 110 If the control device 130 is now controlled in the second control state 134, the first pressure signal is activated, which is now applied to the 2-way flow control valve 120 in the closed control direction by the first control line 123 and thus the effect of the biasing element 122 and can at least partially compensate the LS pressure signal, in particular a function as a pressure compensator for regulating the volume flow can be provided by the proportional directional spool valve 110. Since the time at which the first pressure signal is applied by the first control line 123 in the closed-control direction to the 2-way flow control valve 120 depends on the control state of the control device 130 and in particular on the control signal 136, the time from which can be set with a suitable control signal 136 the 2-way flow control valve 120 acts as a pressure compensator. In particular, the control signal 136 can, for example, regulate the control device 130 from the first control state 132 to the second control state 134 when the first pressure signal is sufficiently high, so that, in particular, a pressure balance function of the 2-way flow control valve 120 only takes place at higher pressure differences and thus a section the characteristic curve in accordance with section a2 in Fig. 1b is minimized or avoided as far as possible above. On the other hand, the 2-way flow control valve 120 can be given a certain inertia, so that undesired rocking with an upstream further control valve (not shown) or an upstream control device for controlling a supply pump (not shown, for example with regard to 1a and 1b is described above), is prevented since regulation is not carried out in this case and thus the rocking is prevented by the decoupled regulating action of the 2-way flow regulating valve 120 in the first regulating state 132 of the regulating device 130.

Fig. 3 schematically shows a characteristic curve in a diagram in which a volume flow Q through the 2-way flow control valve 120 and the proportional directional spool valve 110 along the abscissa against a pressure difference Δp _LS across the 2-way flow control valve 120 and the proportional directional spool valve 110 is plotted along the ordinate. According to the characteristic in Fig. 1b The characteristic curve figure 3 has three sections, a characteristic curve course K1 (similar to section a1 in the characteristic curve) in a first section a indicative of small pressures in Fig. 1b ) corresponds to a dynamic pressure characteristic. In a second section b, the characteristic curve now gives way to Fig. 3 corresponding to a characteristic section K2 from the characteristic curve in section a2 Fig. 1b ab (a characteristic curve according to Fig. 1b is in Fig. 3 on the basis of the dashed curve K3), since here the curve essentially continues to follow the dynamic pressure curve, so that the curve K2 essentially continues the curve K1 according to the dynamic pressure curve. The reason is that the control device 130 is located here Fig. 2 in the first control state 132, so that contrary to the course in Fig. 1b (accordingly a pressure compensator function regarding Fig. 1a occurs in the 2-way flow control valves 41, 42 shown there and is responsible for the deviation from the dynamic pressure characteristic), however, due to the first control state 132, a pressure compensator function of the 2-way flow control valve 120 is blocked by the control device. As a result, the characteristic curve curve K1 continues in accordance with the dynamic pressure characteristic curve in K2. With a well-defined switching into the second control state 136 of the control device 130 in Fig. 2 now takes place in the diagram of Fig. 3 a discrete transition to stable operation, in which the 2-way flow control valve 120, as a pressure compensator, regulates the volume flow through the proportional directional spool valve 110 to a constant value as a function of pressure. A characteristic curve curve S now designates a transition from the characteristic curve curve K2 corresponding to the dynamic pressure characteristic curve to stable control operation according to a characteristic curve curve K4.

As can be seen from the comparison between the characteristic curves K3 and K2, here in particular the pressure losses Δp _LS compared to the case in Fig. 1b kept low, so that less energy is lost or is dissipated in the heating of the hydraulic medium. The characteristic curve corresponding to K1, K2, S, K4 is consequently more energetically favorable than the conventional characteristic curve shown in Fig. 3 is represented by K1, K3 and K4.

Regarding Fig. 4 illustrative embodiments of the invention are described in more detail. Fig. 4 shows a hydraulic module 200 with a supply line 205 and a 2-way flow control valve 220 arranged in the supply line 205. The 2-way flow control valve 220 can correspond to the 2-way flow control valve 120 in Fig. 2 be arranged in front of a proportional directional spool valve, as in Fig. 2 is shown according to the proportional directional spool 110.

In illustrative embodiments, a first control line 223 can be branched off downstream of the 2-way flow control valve 220 at a branch point 209, wherein a first pressure signal is tapped off from the supply line 205 downstream of the two-way flow control valve 220 by means of the first control line 223 at the branch point 209. In A control device 230 is arranged on the first control line 223. The first control line 223 is connected to an input E of the control device 230. At an output A of the control device 230 there is an end section 231 of the first control line 223, which is connected to a connection AS2 of the two-way flow control valve 220, so that a pressure medium in the end section 231 in the closed-control direction to the 2-way flow control valve 220 can act. The 2-way flow control valve 220 is biased in the open control direction by a biasing element 222, for example a mechanical spring element, counter to the action of a pressure medium in the end section 231.

For example, in a Fig. 4 shown first control state 232 of the control device 230, a transmission of the first pressure signal in the first control line 223 at the input E of the control device 230 to an output A of the control device 230, and consequently into the end section 231 of the first control line 223. In a second control state 234, the first pressure signal in the first control line 223 can enter the input E of the control device 230 and enter the end section 231 at the output A of the control device 230 in order to connect to the connection AS2 of the two-way flow control valve 220 in the closed control direction to act on this.

In an illustrative embodiment, the control device 230 has a pretensioning element 235, for example a mechanical pretensioning element, which prestresses the control device 230 in the closed-control direction. According to specific examples, the prestressing element 235 can be adjustable or a prestressing can be set by the prestressing element 235. This means that, for example in the case of a mechanical pretensioning element, it can be set and / or exchanged by an operator or user of the hydraulic module, for example against a pretensioning element with different spring hardness, or a spring force can be changed. In this way, for example, a hard or soft switching characteristic of the control device 230 can be specified. In other words, a hard prestressing element can mean a regulation from the first regulation state 232 into the second regulation state 234 at relatively high pressures in comparison with soft prestressing elements 235, at which even low pressures are sufficient for regulation from the first regulation state 232 into the second regulation state 234 are. Accordingly, a length of the section S in Fig. 3 on the basis of the preload element 235, since in the case of a relatively hard preload element or a relatively heavily preloaded preload element, the 2-way flow control valve is in the first control state 132 over a larger area and thus follows the dynamic pressure characteristic curve "longer".

As continues in Fig. 4 is shown, a further control line 211 can be branched upstream of the 2-way flow control valve 220 at a branch point 207, by means of which a further pressure signal in the open control direction is applied to the control device 230 via the connection AS3 of the control device 230 against the action of the biasing element 235 can be. This means that, depending on a size of the further pressure signal tapped via the further control line 211 at the branching point 207, in comparison to a set bias voltage on the biasing element 235, a switch to the second control state 234 can take place from the first control state 232. It can thereby be set, for example, that the control device 230 can only be switched to the second control state 234 from a certain minimum pressure upstream of the two-way flow control valve 220.

In some illustrative embodiments, as shown in FIG Fig. 4 in addition to an LS control line corresponding to the control line LS1 in Fig. 2 an LS control line LS2 acts on the 2-way flow control valve 220 in addition to the biasing element 222 in the up-control direction, the LS control line LS2 on the up-control side being connected to a connection AS1 on the two-way flow control valve. Furthermore, in some illustrative embodiments, the LS control line LS2 can additionally branch into an optional control line 228 which, at an optional second input E ′ of the control device 230, applies an LS pressure signal tapped at the LS control line LS2, which is applied in the first control state 232 the output A of the control device 230 is transmitted and the first control state 232 of the control device 230 can additionally be applied to the 2-way flow control valve 220 in the closed control direction. This means that the 2-way flow control valve 220 is essentially open-controlled by the biasing element 222. This is not a limitation of the present invention and the control line 228 and the additional second input E ′ of the control device 230 cannot be provided.

In some illustrative embodiments, the control line 228 can also be branched into a further optional control line 229 before the input E ′ in order to apply the LS pressure signal tapped via the LS control line LS2 to the control device 230 on the control side in addition to the biasing element 235. In some illustrative examples herein, contrary to what is shown in Fig. 4 also be dispensed with the second input E '. The LS pressure element tapped via the LS control line, which is applied to the control device 230 via the control line 228 and 229, is compared with the further pressure signal, which is tapped at the branch point 207 by means of the further control line 211 and on the control side to the control device 230 is attacked counteractively, so in this If the control device 230 is controlled on the basis of the pressure difference between the branch point 207 and an LS pressure signal tapped downstream of the two-way flow control valve 220. In this way, for example, control operation of the control device 230 can be stabilized and a first pressure signal applied to the two-way flow control valve in the second control state 234 can, for example, be kept at a constant level regardless of the load. This makes the two-way flow control valve less sensitive to pressure fluctuations in the LS system.

Fig. 5 schematically shows one to Fig. 2 alternative embodiment, in which case the hydraulic module shown here can also be integrated, for example, in a valve block or alternatively can be composed of different sub-modules. To Fig. 2 Similar or identical elements are provided with the same reference symbols and for a description of these elements reference is made to the description in this connection Fig. 2 directed. In particular, a pressure-controlled 2-way flow control valve 120 is provided, which is arranged upstream of a proportional directional spool valve 110 in a supply line 105, as well as in connection with Fig. 2 was described above.

In contrast to that in Fig. 2 The illustrated embodiment is the 2-way flow control valve 120 in the illustration of FIG Fig. 5 pressure-controlled via a control device 330. The control device 330 is arranged in a first control line 323, which taps a first pressure signal upstream of the 2-way flow control valve 120, which can optionally be applied or blocked by the control device 330 in the up-control direction of the 2-way flow control valve 120. The control device 330 may, according to illustrative embodiments, as in FIG Fig. 5 is shown as an example, designed as a 2-way valve with two discrete switching positions. In a first control state 332 of the control device 330, application of the first pressure signal via the first control line 323 in the open control direction to the 2-way flow control valve 120 is permitted or enabled, in particular the control device 330 is opened in the first control state 332. In a second control state 334 of the control device 330, the first pressure signal tapped by the first control line 323 is blocked and is not applied to the 2-way flow control valve 120, in particular the control device 330 is closed in the second control state 334.

According to illustrative embodiments, the control device 330 can be controlled as a function of a signal 336. In some illustrative examples, signal 336 may represent a hydraulic control signal. In alternative examples, signal 336 may represent an electromagnetic control signal (e.g., an electrical signal for actuation an electromagnet, which can selectively set the first control state 332 or the second control state 334). In some specific examples herein, a pressure sensor may be disposed in the supply line 105 upstream of the 2-way flow control valve 120 and / or downstream of the 2-way flow control valve 120 and / or downstream of the proportional directional spool valve 110, so that control of the control device 330 into a desired control state of the first and second control states 332, 334 depending on the at least one tapped pressure signal.

As shown in Fig. 5 can, by means of the control device 330, an LS pressure signal, which is applied via an LS line LS1 in the up-control direction to the 2-way flow control valve 120 to support the biasing by the biasing element 122, in the first control state with the first pressure signal or supported by this in the up-control direction to the 2-way flow control valve 120. Similar to the biasing element 122 Fig. 2 , can that in Fig. 5 shown biasing element, for example, a mechanical spring element that mechanically biases the 2-way flow control valve 120 in the open control direction. According to specific illustrative examples herein, it is not absolutely necessary that the 2-way flow control valve be fully opened in the open-control direction solely by the action of the biasing element 122.

In illustrative embodiments, a first pressure signal, which is tapped in the supply line upstream of the 2-way flow control valve 120 by means of the first control line 323 and is applied to the 2-way flow control valve 120 in the up-control direction thereof, in addition to an LS pressure signal, If the control device 330 is switched to the first control state 332, it can be compared with a second pressure signal which is tapped downstream of the 2-way flow control valve 120, for example between the 2-way flow control valve and the proportional slide valve 110, via a second control line 339 and depending on the bias by the biasing element 122, a volume flow through the 2-way flow control valve 120 and the proportional directional spool 110 can be set based on the pressure difference between the first pressure signal and the LS pressure relative to the second pressure signal. In particular, the 2-way flow control valve 120 can be completely open-controlled as long as the control device 130 is in the first control state 332. If the control device 130 is in the second control state 334, the 2-way flow control valve can generate a volume flow through the 2-way flow control valve 120 and the proportional directional spool valve 110 on the basis of the pressure difference between the LS pressure (tapped via the LS line LS1) and the second pressure signal can be set. Thus, in the second control state 334 of the control device 330, a volume flow through the 2-way flow control valve 120 and the proportional directional spool valve 110 can be set in accordance with the stroke of the proportional directional spool valve 110. On the other hand, the 2-way flow control valve 120 has no regulating effect as long as the control device 330 is in the first control state 332. The volume flow through the proportional directional spool valve 110 thus essentially follows a dynamic pressure characteristic curve, ie the pressure loss across the proportional directional spool valve 110 and the 2-way flow control valve 130 is essentially proportional to the square of the volume flow rate and indirectly proportional to the control cross section in the proportional directional spool valve 110 If the control device 330 is now controlled in the second control state 334, the first pressure signal, which is applied in the first control state 332 by the first control line 323 in the closed control direction to the 2-way flow control valve 120, and thus the effect of the biasing element 122 and the LS pressure signal added, blocked. So that in the Fig. 5 Embodiment shown a function as a pressure compensator for regulating the volume flow through the proportional directional spool 110 depending on the LS pressure and the second pressure signal are provided. Since the time at which the first pressure signal is applied by the first control line 323 in the up-control direction to the 2-way flow control valve 120 depends on the control state of the control device 330 and in particular on the control signal 336, the time from which can be set with a suitable control signal 336 the 2-way flow control valve 120 acts as a pressure compensator. In particular, the control signal 336 can, for example, regulate the control device 330 from the first control state 332 to the second control state 334 with a sufficiently high first pressure signal, so that, in particular, a pressure balance function of the 2-way flow control valve 120 only takes place at higher pressure differences, and thus a section the characteristic curve in accordance with section a2 in Fig. 1b is minimized or avoided as far as possible above. On the other hand, the 2-way flow control valve 120 can be given a certain inertia, so that undesired rocking with an upstream further control valve (not shown) or an upstream control device for controlling a supply pump (not shown, for example with regard to 1a and 1b is described above), is prevented since regulation is not carried out in this case and thus the rocking is prevented by the decoupled regulating action of the 2-way flow regulating valve 120 in the second regulating state 332 of the regulating device 330. The explanations are now closed Fig. 3 above also on the in Fig. 5 illustrated embodiment can be transferred accordingly.

Regarding Fig. 6 is now an illustrative example of the in Fig. 5 illustrated embodiment described in more detail.

It is a hydraulic module 400 with a 2-way flow control valve 420 (corresponds to the 2-way flow control valve 120) Fig. 5 ) shown upstream in a supply line 405 a proportional spool valve, not shown, is arranged. Upstream of the 2-way flow control valve 420 (corresponds to the 2-way flow control valve 120 Fig. 5 ) a first control line is branched off at a branch point 419. The first control line is connected to an input E "of a control device 430, which corresponds to the representation in FIG Fig. 6 can be designed as a 2-way valve which is biased in the open control direction by a biasing element 435, for example a mechanical spring or the like. A prestress provided by the prestressing element 435 can be adjustable, for example the prestressing element 435 can be exchangeable or the prestressing exerted by the prestressing element 435 can be set as desired by an operator using a tool.

Upstream of the control device 430, a pressure signal can be tapped off in the first control line 423 by means of a first signal line 424 and can be applied to the control device 430 in the closed control direction of the control device 430 against the action of the biasing element 430.

The control device 430 can be connected on the output side (at an output A ′ of the control device 430) to a continuation 431 of the first signal line 423, which is connected to an LS line LS3 (similar to the LS lines LS1 and LS2). In the continuation 431, a second signal line 429 is provided downstream of the control device 430, by means of which a pressure signal downstream of the control device 430 can be tapped in the first control line and can be applied to the control device 430 in the open control direction to support the biasing element 435. Accordingly, the control device is regulated as a function of a pressure difference between the pressure signals which are tapped by the signal lines 424 and 429 in the first control line (relative to the pretension by the pretensioning element 435). If an effect of a pressure reported by the first signaling line 424 now exceeds an effect of a pressure reported by the second signaling line 429 in combination with the effect of the biasing element 435, the control device 430 is controlled. This blocks transmission of the first pressure signal, which is tapped via the first control line 423, to the LS line LS3 and to the 2-way flow control valve 420.

For example, the control device 430 can, depending on a pressure signal that is applied to the control device 430 via the first signal line 424, and a further pressure signal that is applied to the control device 430 via the second signal line 429, into a first control state 432 or a second control state 434 are brought, the first pressure signal in the first control state 432 by the control device 430 in the open control direction is applied to the 2-way flow control valve 420. In the second control state 434, application of the first pressure signal to the 2-way flow control valve 420 is blocked. Accordingly, the 2-way flow control valve 420 can be closed in the first control state 432 of the control device, while in the second control state 434 of the control device 430 it is open-controlled, for example completely open-controlled. The first pressure signal can be applied to the 2-way flow control valve 420 in the second control state 434 of the control device 430, while an application of the first pressure signal is blocked in the first control state 432 of the control device 430.

There can be an LS pressure signal, as shown by the arrow p_LS in Fig. 6 is shown, either from a combination of the LS pressure reported by the LS line LS3 with the first pressure signal (if the control device 430 is open-controlled) or solely from the LS pressure reported by the LS line LS3 (if the control device 430 is controlled) are applied to the 2-way flow control valve 420 in the open control direction.

Furthermore, a further control line (second control line) 452 can be branched off downstream of the 2-way flow control valve 420 at a branch point 450, by means of which a further (second) pressure signal in the closed control direction to the 2-way flow control valve 420 against the action of a biasing element 422 and the LS pressure signal, possibly combined with the first pressure signal. In particular, the effect of the second pressure signal is at least partially compensated for by the first pressure signal when the control device 430 is open, so that the 2-way flow control valve 420 is opened.

Fig. 7 shows characteristic curves of the volume flow through the above-described proportional directional spool valve as a function of the pressure difference Δp above the 2-way flow control valve and the proportional directional spool valve described above. In particular, a characteristic curve with a dotted curve shows the case of a high control pressure, while a characteristic curve with a dash-dotted curve shows the case of a low control pressure in relation to the in Fig. 3 shown characteristic curve (solid curve) means. A characteristic curve or the regulating pressure is set via the adjustable preloading elements, a "harder" preloading element or a preloading element with "greater" preload meaning a "higher regulating pressure. As shown in FIG Fig. 7 the result is a length of a standard edge, as in Fig. 7 on the basis of the double arrow labeled “Δx”, by means of which the adjustable prestressing element can be set depending on the application.

The structure and function of a hydraulic module with a 2-way flow control valve were described above, which according to some illustrative embodiments in proportional directional spool valves can be used with LS technology. The 2-way flow control valve can be connected upstream or downstream of the individual proportional directional spools or valves. Here, a pressure drop across the proportional directional spool valve, in particular via a measuring orifice in the proportional directional spool, is kept constant, and the volume flow through the proportional directional spool can also be kept constant regardless of the pump pressure or a load pressure at the consumer. In the case of 2-way flow control valves upstream of proportional directional spool valves, the 2-way flow control valve always regulates the pressure that is present directly in front of the proportional directional spool valve (and thus in front of the measuring orifice in the proportional directional spool valve) by the same pressure difference as the consumer pressure.

The control device, which according to illustrative embodiments based on the 2 to 7 The advantages described above have the following advantages: Fig. 1b Section "a2" of the characteristic curve described is bypassed. The two-way flow control valve is open-controlled in this area regardless of the load pressure. By suspending the control of the 2-way flow control valve in this area, energy savings are achieved. Furthermore, independence from special settings on pump controllers or on controllers in the connection block to the hydraulic module is achieved.

In some illustrative embodiments, the control device described above ensures that the 2-way flow control valve is opened up to a certain set pressure difference and that there is no counteracting control on the 2-way flow control valve. In essence, the behavior of the 2-way flow control valve is influenced by the biasing element up to a certain adjustable pressure difference. In special illustrative embodiments, the 2-way flow control valve is completely open-controlled in this pressure range. Only from a certain pressure difference and / or a sufficiently high pressure difference is there a regulating operation of the 2-way flow control valve by at least partially compensating for the opening effect of the prestressing element. The pressure difference from which the 2-way flow control valve switches to regulating operation can be set via the control device.

In the embodiments described above with reference to the figures, there is talk of a proportional directional spool valve and a consumer. This does not represent a limitation of the present invention. Instead of a consumer and a proportional directional spool valve, analogy to the illustration in FIG Fig. 1a Two proportional directional spool valves and two consumers or even more than two proportional directional spool valves and more than two consumers are provided, with a 2-way flow control valve in front of at least one proportional directional spool valve can be provided and one of the 2-way flow control valves is pressure-controlled by a control device, as described above. In an advantageous embodiment herein, the 2-way flow control valve pressure-controlled by the control device can be assigned to a consumer which is exposed to the greatest load during operation.

Claims (14)

1. Hydraulic module (200; 400) comprising a pressure-controlled 2-way valve (220; 420) arranged in a supply line (205; 405) of the hydraulic module (200; 400), wherein the pressure-controlled 2-way valve (220; 420) is biased by a first biasing element (222; 422) in the open control direction, wherein a first pressure signal, which is tapped downstream or upstream of the pressure-controlled 2-way valve (220; 420) in the supply line (205; 405), is applicable to the pressure-controlled 2-way valve (220; 430) via a first control line (223; 423) accordingly in the close control direction or the open control direction, wherein a control device (230; 430) is arranged in the first control line (223; 423) for pressure control of the pressure-controlled 2-way valve (220; 420), wherein the control device (230; 430) is configured to block application of the first pressure signal to the pressure-controlled 2-way valve (220; 420) in a first control state (232), while the first pressure signal is applicable to the pressure-controlled 2-way valve (220; 420) by the control device (230; 430) in a second control state (234; 434), characterised in that the 2-way valve is configured as a 2-way flow control valve.
2. Hydraulic module (400) according to claim 1, wherein the first control line (423) is tapped upstream of the pressure-controlled 2-way flow control valve (420) in the supply line (405), the hydraulic module (400) further comprising a first signal line (424), which is branched off upstream of the control device (430) in the first control line (423), wherein the control device is switchable into the first or second control state in accordance with a pressure signal tapped off by the first signal line (424).
3. Hydraulic module (200) according to claim 1, wherein the first control line (223) is tapped downstream of the pressure-controlled 2-way flow control valve (220) in the supply line (205), the hydraulic module (200) further comprising a second control line (211), which is connected to the supply line (205) upstream of the pressure-controlled 2-way flow control valve (220), wherein the control device (230) is switchable into the second control state (234) in accordance with a second pressure signal tapped by the second control line (211).
4. Hydraulic module (200; 400) according to any one of claims 1 to 3, wherein the control device (230; 430) comprises a pressure controlled 2-way valve, which is biased by a second biasing element (235; 435), wherein the pressure controlled 2-way valve (230; 430) in the first control state (232; 432) is closed-controlled, while in the second control state (234; 434) it is open-controlled, so that the first pressure signal is applicable to the pressure-controlled 2-way flow control valve (220; 420) when the pressure-controlled 2-way valve (230; 430) is open-controlled.
5. Hydraulic module (200) according to claim 4 in combination with claim 3, wherein the second pressure signal is applicable via the second control line (211) to the pressure-controlled 2-way valve (230) in the open control direction.
6. Hydraulic module (200; 400) according to one of claims 1 to 5, further comprising a third control line (LS2; LS3) connected to the supply line (205; 405) downstream of the pressure-controlled 2-way flow control valve (220; 420), wherein a third pressure signal is applicable via the third control line (LS2; LS3) to the pressure-controlled 2-way flow control valve (220; 420) in the open control direction.
7. Hydraulic module (200) according to claim 6 in combination with claim 2, further comprising a fourth control line (228) which is connected to the third control line (LS2), wherein the third pressure signal is applicable to the control device (230) via the fourth control line (228) and the control device is switchable to the first control state (232) in accordance with the third pressure signal.
8. Hydraulic module (200) according to claim 6 or 7 in combination with claim 2, wherein the third pressure signal is applicable to the pressure-controlled 2-way flow control valve (220) in the first control state (232) of the control device (230) in the close control direction.
9. Hydraulic module (100) according to any one of claims 1 to 8, further comprising a proportional directional control valve (110) arranged in the supply line (105) downstream of the pressure-controlled 2-way flow control valve (120).
10. Hydraulic module (100) according to claim 9 in combination with one of claims 6 to 8, wherein the first pressure signal is tapped upstream of the proportional directional control valve (110) and the third pressure signal is tapped downstream of the proportional directional control valve (110).
11. Hydraulic module (200) according to any one of claims 1 to 10, wherein the 2-way flow control valve (220) and the control device (230) are integrated into a valve block.
12. Hydraulic module (200) according to any one of claims 1 to 11, wherein the control device (230) has only the first and second control states (232, 234) as two discrete switching positions.
13. Hydraulic module (200) according to any one of claims 1 to 12, wherein the control device (230) comprises an adjustable biasing element (235) by which the control device (230) is biased to the first control state (232).
14. Hydraulic module system comprising at least two hydraulic modules, wherein only one of the at least two hydraulic modules is configured according to the hydraulic module (200) according to any one of claims 1 to 13.

Images