DE102012007108A1 - Valvistor arrangement has pilot branch, in which pilot valve and associated pressure regulator are arranged, where pressure regulator is arranged downstream of pilot valve - Google Patents

Abstract

The Valvistor (RTM: Proportional flow control valve) arrangement has a main stage (2), whose valve body is acted upon the pressure in a control chamber (20) in a closing direction. A pilot branch is provided, in which a pilot valve (4) and an associated pressure regulator (6) are arranged, where the pressure regulator is arranged downstream of the pilot valve. The pilot valve is a continuously adjustable throttle, where the pilot valve is electrically, electromagnetically proportional, hydraulically or manually adjustable.

Description

The invention relates to a Valvistoranordnung according to the preamble of claim 1.

Such a Valvistoranordnung is for example in the EP 0 541 338 B1 , of the EP 0 079 870 B1 and the DE 101 24 154 A1 discloses and allows a load pressure independent control of consumers.

A conventional valvistor has a main stage, which is designed with a poppet valve and which is controlled by a pilot valve. The main stage has a valve body biased by a weak spring over a valve seat. In the cone or in the cone surrounding the cartridge, a control slot is formed, via which an input port is connected to a control chamber, via which a valve seat remote from the end face of the cone is acted upon in the closing direction. This control chamber can be connected via the pilot valve to the output terminal of the main stage. In the known solutions, the pilot valve is designed as an adjustable throttle, which is assigned to the load pressure independent constant holding the control oil flow through the pilot valve this a pressure compensator.

When testing such Valvistoranordnungen show that the control behavior is difficult to control with low pressure medium demand of a consumer, which can lead to sudden changes in the pressure medium flow rate.

In contrast, the invention has for its object to provide a Valvistoranordnung whose response is improved.

This object is achieved by a Valvistoranordnung with the features of claim 1.

Advantageous developments of the invention are the subject of the dependent claims.

The Valvistoranordnung invention has a main stage, the valve body is acted upon by a pressure in a control chamber in the closing direction. The Valvistoranordnung further has a pilot control branch in which an acting as an adjustable throttle pilot valve and an associated pressure compensator are arranged. According to the invention, the pressure compensator is arranged in the downstream direction from the control chamber downstream of the pilot valve. It has surprisingly been found that this relative positioning of the pressure balance, the response at low pressure medium flow rates compared to the prior art is significantly improved, in which the pressure balance upstream, d. h., Is arranged in the control oil flow path between the control chamber and the pilot valve.

In one embodiment of the invention, the pilot valve is designed as a continuously variable throttle, wherein the main stage forms a throttle having a substantially constant cross-section. Between these two throttles, the control chamber is then executed, wherein the effective control pressure in the control chamber by controlling the variable throttle of the pilot valve is variable.

The pilot valve may be mechanical, fully electric, electro-proportional or hydraulic.

According to the invention it is preferred if the pressure compensator is acted upon by the pressure upstream of the main stage in the closing direction and the pressure downstream of the pressure compensator in the opening direction.

An output port of the main stage may be connected to low pressure, in which case the pressure compensator also opens to low pressure. Under low pressure is not necessarily a tank pressure or the like understood, but only a portion of the Valvistoranordnung, which is acted upon by a lower pressure than the pressure at the input of the main stage.

In one embodiment, it is provided that the output terminal of the main stage is connected to a working line to the consumer, in which case the pressure compensator opens to this working line.

According to the invention it is preferred if the main stage is designed as a 2-way valve whose valve body is acted upon in the opening direction by the pressure upstream of the main stage and which is designed with a control channel between the control chamber and a control chamber which is acted upon by the pressure acting in the opening direction.

The main stage is preferably carried out with area ratio.

According to the invention, the pressure compensator is designed with an area ratio, this corresponds approximately to the area ratio of the main stage.

In a particularly compact solution, the main stage and the pilot valve are arranged in a cartridge.

The space can be further minimized, even if the pressure compensator is integrated into the cartridge.

The pressure compensator can be arranged, for example, in a main cone of the main stage.

The Valvistoranordnung can be designed for two flow directions, wherein it is designed with a common main stage and a common pilot valve and each flow direction is associated with a pressure compensator.

To avoid pressure peaks, a pressure relief valve may be provided in the high-pressure branch.

Preferred embodiments of the invention are explained in more detail below with reference to drawings.

Show it

1 a circuit diagram of a valvistor arrangement in meter-in circuit,

2 a valvistor in meter-out circuit,

3 the principle control of a double-acting consumer,

4 a circuit diagram for controlling a double-acting consumer,

5 a part of the circuit 4 with electroproportional control,

6 a circuit diagram for controlling a double-acting consumer,

7 a UF valve of the circuit 6 .

8th a lid for a Valvistor control block with electroproportional control (meter-IN),

9 a lid with electroproportional control (meter-OUT),

10 a concrete solution for controlling a double-acting consumer with a lid according to 9 .

11 a side view on the control block 10 .

12 a valvistor in meter-in circuit,

13 a concrete solution of the valvistor 12 .

14 a circuit diagram of a valvistor in meter-out circuit,

15 a concrete solution of the embodiment according to 14 . 16 a circuit diagram of a valvistor arrangement in meter-in and meter-out circuit,

17 a concrete embodiment of the circuit according to 16 .

18 a valvistor with a simplified meter-in / meter-out circuit and pressure relief valve,

19 a concrete embodiment of the circuit according to 18 .

20 a circuit of a valvistor in meter-in version,

21 a concrete embodiment of the valvistor according to 20 .

22 a valvistor in meter-out circuit,

23 according to the Valvistor 22 in a concrete execution,

24 a valvistor arrangement with meter-in / meter-out function,

25 a concrete embodiment of the valvistor according to 24 .

26 a circuit diagram of a valvistor arrangement in meter-in / meter-out function and pressure relief valve,

27 a concrete embodiment of the circuit according to 26 .

28 a basic circuit diagram for a valvistor arrangement for supplying pressure medium to a double-acting consumer with electro-proportional control,

29 a corresponding circuit diagram with hydraulic control,

30 a variant of a valvistor in meter-in circuit, 31 a concrete version of a valvistor in meter-out circuit with pressure relief and suction valve,

32 a circuit diagram of a valvistor arrangement for controlling a single-acting consumer,

33 the circuit diagram according to 32 with a storage valve,

34 the circuit diagram according to 32 with a rapid-action valve,

35 a circuit diagram of a wheel loader circuit with Valvistor control blocks with purely electro-proportional control,

36 a circuit diagram with a wheeled excavator circuit with Valvistor arrangements with electroproportional control,

37 a circuit diagram of a crawler circuit with Valvistor arrangements with electro-proportional control and

38 to 40 the schematics according to the 35 to 37 with hydraulic control of a pump.

The Valvistor arrangements described below can be used as a controllable control system, which keeps the pressure medium volume flow constant in the inlet and outlet of a consumer regardless of pressure. Such a circuit can be used, for example, where usually throttle systems control linear or rotational movements. They are suitable for controlling large pressure medium flow rates and can be used in particular in excavators, wheel loaders, rollers, milling, industrial machinery, special vehicles, etc. In principle, can be omitted by such pressure-compensated Valvistor arrangements required in conventional solutions lowering and driving brake valve. Use in open and closed circuits is possible. The construction volume of the Valvistor control blocks described below corresponds to about two-thirds of a conventional control block with the same capacity, the structure of the system according to the invention is much simpler.

In the meter-in systems explained in greater detail below, the main stage of the valvistor arrangement is designed with a surface differential piston which has a control cross-section which opens proportionally to the stroke. Via a hydraulic or electroproportional adjustable diaphragm, the pilot oil flows to a designed as a pressure compensator compensator. This is when driving in the overlap and opens muted when the pilot oil begins to flow. After a certain amount of control, the main stage follows and regulates load-independent the pressure medium flow to the consumer.

In the downstream meter-out system, the function is basically the same as in the meter-in solution with the difference that the flow from the consumer-side connection to the outlet (T) takes place. In addition, in this system, the inlet and outlet side of a consumer is protected by the integrated overpressure function. In the event of cavitation at the consumer, the main piston opens to the tank.

For a better understanding of the detailed explanation of the figures, the basic function of the components of a valvistor according to the invention is again explained. This has a logic main stage, which is controlled via a continuously adjustable pilot valve, wherein downstream of the pilot valve, a pressure compensator is arranged.

With the meter-in circuit, the pressure applied to the input keeps the main plug of the main stage closed when no oil can escape from the control chamber. The piston spring force is relatively small (0.5 to 2 bar), because it is a disturbance in the control system and keeps the logic (main stage) closed without hydraulic load. In principle, the spring can also be dispensed with. The main level is a short and relatively small inexpensive part and can be swapped out quickly for a different amount and translation. The design of the abovementioned control grooves which open in proportion to the stroke takes place depending on the conditions of use. These control grooves can be designed according to the control philosophy linear, progressive or degressive. It should be noted that a pilot groove has the same cross-sectional shape as the main stage. The logic (main stage) itself is designed for stability reasons with a surface difference, which complicates the pressure compensator function, but here is advantageous.

The pilot valve has the task to bring with proportional cross-sectional opening the main cone in a defined stable position and to hold there. The change in cross section must be done under a constant load pressure independent pressure curve, otherwise the logic can not maintain its position. In the closed position, the pilot valve is leak-free. Ie. at rest, the current regulator formed by the pilot valve and the pressure compensator is closed, and from this closed position, the control of the main stage is carried out. In order to limit the pressure medium volume flow to the consumer, the pilot valve can be designed with a stroke limitation.

The pressure balance (compensator) has an important task in the control system: in the case where the pilot flow is zero, the piston of the pressure compensator is pressed and held by the pump pressure against the control spring up to the stop. Constructively, the compensator is constructed so that it shuts off the throttle space from the consumer space, so that a soft and slow opening of the main stage can be initiated. The pilot control operates only pressure independent until the saturation of the main piston groove. The amount of control oil is determined by the compensator spring. After saturation, the main cone follows continuously until an equilibrium of forces sets in - a load pressure-independent control is thus ensured.

In the case of an ancillary consumer's lead, the main cone controls and maintains the high pressure from the other consumer. In the case where the pump pressure breaks down, the pressure balance opens completely and the main stage (logic) follows. In this case, the available quantity of pressure medium flows to the leading consumer, so that cavitation is suppressed.

As already mentioned, in the meter-out circuit, the running loop is controlled as described in the meter-in circuit. In the case where the tank pressure is higher than the consumer pressure, a Nachsaugung is possible, which requires a certain Voröffnungsquerschnitt, so that the opening time (≤ 200 msec) remains small.

The meter-out circuit also acts as a pressure relief valve, with the main stage opening and limiting the load on the secondary side.

The pressure balance has an additional adjustment integrated. Increasing the control spring force changes the amount of control and the main stage does not stress the consumer.

1 shows a valvistor arrangement, hereinafter for the sake of simplicity Valvistor 1 called, in meter-in circuit. As already explained, the Valvistor has 1 a main stage executed as logic 2 , which is a pilot valve 4 assigned. Downstream of this pilot valve 4 is arranged a compensator, hereinafter referred to as pressure compensator 6 is designated. The main logic stage 2 has a main cone 8th , which is carried out with a surface difference, in the present case, an area ratio A1 / A2 of 1: 1.138. An input port P is a pressure line 10 to a pressure medium supply, such as a pump connected.

A work connection A is via a work line 12 in fluid communication with a consumer. The main cone 8th is in the illustrated rest position with an annular end face 130 on a seat 14 on. The main cone 8th is in this rest position by means of a weak spring 16 biased, which corresponds for example to a pressure equivalent of 1 to 2 bar. At the outer circumference of the main cone 8th is a variety of tax rates 18 trained in a control room 20 open, which also acts as a spring chamber. These taxes 18 are in fluid communication with the input port P. This is for example in the main stage 8th a pressure port side opening axial bore 22 arranged over radial bores 24 in the tax ways 18 opens, so that in the illustrated rest position in the control room 20 the pressure at the input connection is effective. Due to the area difference and the power of the weak spring 16 thus becomes the main cone 8th biased against his seat. The opening cross section of the control grooves 18 increases with the stroke of the main cone 8th , In the axial bore 22 furthermore, at least one transverse bore opens 26 , about after a predetermined stroke of the main cone 8th a pressure fluid connection to the consumer port A can be produced. In the consumer line 12 is a designed as a check valve load-holding valve 28 arranged. The consumer pressure at port A can be tapped via an LS line, in which a LS-check valve 30 is arranged.

The pilot valve 4 is also designed as a seat valve, with a cone 32 via a spring arrangement 34 against a pilot seat 36 is biased. Ie. the pilot valve 4 is closed in its rest position. An input port P 'of the pilot valve 4 is via a pilot channel 38 with the control room 20 connected. An output port B is connected to an input port P "of the pressure compensator 6 connected. The cone 32 is with an axially projecting control collar 40 executed, whose control surface 42 (A3) can be acted upon by a control pressure PST to the cone 32 from the pilot seat 36 take off, so that a pressure fluid connection from the control room 20 to the pressure balance 6 is turned on. As in 1 indicated, the spring chamber for the spring assembly is relieved to a tank T out. The force of the spring arrangement 34 corresponds to a pressure equivalent of about 7 to 22 bar in the illustrated embodiment.

The pressure balance 6 has a DW piston 42 which is biased by a DW spring (pressure equivalent about 10 bar) toward a rest position in which a Steuerolverbindung from the input terminal P '' to an output terminal Y is opened. This output terminal Y is via an in-control channel 46 with the working connection A of the main stage 2 connected. The DW piston 42 is also designed with a surface difference equal to that of the main piston; ie in the present case is also the pressure balance 6 with an area difference A3 / A4 of 1: 1,138. On the in the closing direction effective end face A3 acts while the pressure at the input port P of the main stage, via a pressure control line 48 is tapped. In the opening direction acts on the pressure balance 6 the pressure downstream of the pilot valve 4 , ie the pressure at the port P '', via an angle channel 50 with a throttle cross-section 64 of the DW piston 42 is tapped, on the one hand in an input-side pressure chamber and on the other hand in the spring chamber for the DW spring 44 empties. The function of this meter-in circuit is explained above.

2 shows the Valvistor 1 in meter-out circuit. As mentioned, the basic structure is the same as in the embodiment according to FIG 1 with the exception that the pressure medium volume flow from the consumer port A at the main stage 2 in the direction of an output-side tank connection T is directed. The main cone 8th is executed with the meter-out circuit with a slightly larger area difference A1: A2. In the illustrated embodiment, this area difference is 1: 2.2842. The tax people 18 open at the entrance of the meter-out circuit, ie at the working port A. The output port T is connected to a tank line 52 connected. In the illustrated embodiment is in the main cone 8th a suction valve 54 integrated with pressure limiting function. This opens when the pressure in the tank line 52 is higher than the consumer pressure, so that pressure medium can be sucked to the consumer and in the pilot branch. In the pressure limiting function, a pressure medium connection to the tank T is opened, so that the consumer pressure is limited on the secondary side.

The construction of the pilot valve 4 corresponds to that of the above-described embodiment.

The pressure balance 6 (Compensator) is according to the area ratio of the skin stage 2 also with an area ratio A3 / A4 of in the present case of 1: 2.2842. The output port Y of the pressure compensator 6 is with the tank line 52 while the input port P "is connected to the output port B of the pilot valve 4 is in pressure medium connection.

In the closing direction acts on the DW piston 42 the pressure at working port A, via an out control port 47 is tapped. In the opening direction, in turn, the pressure acts downstream of the pilot valve 4 at the input port P '' via the angle channel 50 and the throttle cross-section 64 is tapped. In the illustrated embodiment, the bias of the DW spring 44 via an adjusting device 56 variable executed. The adjustment range is between 10 and 15 bar. The remaining embodiment of the meter-out circuit corresponds to that of the above-described embodiment, so that further explanations are unnecessary.

In both circuits described above is when opening the main cone 8th from the seat 14 lifting ring end face 130 subjected to the pressure at the consumer port A.

3 shows a part of a basic circuit for supplying pressure medium of a double-acting consumer, in the present case a linear consumer, for example, as a hydraulic cylinder 58 is executed. Instead of such a linear consumer can of course also a rotary consumer, for example, a hydraulic motor for a slewing or a traction drive can be controlled. The pressure medium supply takes place via a Valvistor control block 60 , which is designed with a tank connection T, a pressure connection P, an LS connection LS and two load connections A, B. The operation of the Valvistor control block 60 can be done hydraulically or alternatively electrically (EP).

In 4 is the circuit diagram of the valvistor control block 60 for the pressure medium supply of a linear or rotary consumer, wherein the actuation of the pilot valves of the respective Valvistoren takes place hydraulically. This circuit has two in each case in meter-in circuit executed Valvistoren 1a . 1c and two valvistors running in meter-out circuit 1b . 1d , wherein the respective basic structure corresponds to the embodiments, which are based on the 1 and 2 were explained.

To simplify the drawing effort is in the illustration according to 1 only the meter-in circuit 1a provided with reference numerals, the meter-in circuit of the valvistor 1c is executed accordingly. As stated above, the valvistor has 1a in the meter-in circuit a main stage 2a whose control room 20 via a pilot control branch with the pilot valve 4a and the pressure balance 6a with the consumer connection, here the connection B is connectable. As previously described, the main level is 2a with an area ratio of 1: 1,138. In the closing direction, the pressure at the pressure connection P acts via the control grooves 18a is tapped, whose cross section increases with the hub. In the closing direction also acts the weak spring 16a , In the opening direction, the pressure at the pressure port P and the pressure at the port A acts on that on the seat 14a resting annular face 130 acts. This effective in the opening direction control pressure path is in 4 also marked.

The effective in the closing direction control pressure is through the pilot valve 4a and the downstream of this pressure compensator 6a certainly. As explained, is the pilot valve 4a executed as a continuously variable throttle, wherein the throttle cross-section in the illustrated embodiment is hydraulically variable via the control pressure PST. In the closing direction is the pilot valve 4a by the force of the spring arrangement 34a applied. The output port D of the pilot valve 4a is with the input port P '' of the pressure compensator 6a connected.

The pressure at this input port P "acts on the DW piston 42 in the opening direction, in the same direction, the force of the DW spring acts 44a , In the closing direction is the DW piston 42 acted upon by the pressure at the pressure port P, via the pressure control line 48a is tapped. In the same direction acts on the DW piston, the pressure at the output terminal Y, in the illustration in accordance with 1 on an annular shoulder 62 the pressure balance 6a ( 1 ) acts. As previously described, the pressure compensator is located 6a at rest, ie with the pilot valve closed 4a in its closed position, as acts in this direction, the high input pressure and is then moved with the pilot valve open in the direction of its open position, this upsetting occurs due to the positive coverage with a relatively smooth transition. The area ratios and pressure-force ratios of the meter-in circuit according to 4 correspond to those of the embodiment in 1 ,

Similarly, the meter-out circuit is the valvistor 1b and 1d according to the embodiment in 2 executed. Accordingly, the consumer port B of the valvistor control block 60 via a work management 66 to the input terminal B of the meter-out main stage 2 B connected, whose output terminal T via the common tank line 52 with the tank connection T of the Valvistor control block 60 connected is.

The main stage 2 B is in the opening direction of the pressure at port B and by the front side on the annular end face 130 ( 1 ) acting tank pressure applied. In the closing direction, the spring acts 16b and the pressure at port B, over the control grooves 18b tapped with variable cross-section. The control pressure acting in the closing direction is in turn via the meter-out pilot valve 4b changeable, which is also hydraulically adjustable. Downstream of the meter-out pilot valve 4b is the meter-out pressure compensator 6b provided, the input terminal P '' to the port B of the pilot valve 4b is connected while the output terminal Y via the tank control channel 68b with the tank line 52 connected is. As explained, the pressure compensator is 6b in the closing direction from the pressure at working port B, via the OUT control channel 47b is tapped off, and on the ring shoulder 62 (please refer 2 ) applied effective pressure at the output terminal Y. In the opening direction is the meter-out pressure compensator 6b by the power of the DW spring 44b and the pressure at the port P '' acted upon, via the one throttle cross-section 64b forming angle channel 50b is tapped.

Also shown in the illustration according to 4 are the dash-dotted indicated Nachsaugventile 54b . 54d with pressure limiting function, which are intended for secondary pressure limitation of the consumer pressure and to avoid cavitation.

Depending on the direction of movement a, b of the consumer is then in the manner described above for pressure medium supply to the consumer of the respective meter-in Valvistor 1a . 1c controlled and the pressure medium control of the effluent from the consumer pressure medium flow rate then each located in the drain Valvistor 1b respectively. 1d driven.

In order to avoid an undesirable lowering of the consumer, the load-holding valve explained in the introduction is in the respective inlet 28a . 28c intended. Upstream of this load-holding valve 28a is via the LS line and arranged therein LS-check valve 30a ( 30b ) The load pressure at the consumer tapped.

As mentioned, the structure of the other meter-in circuits and the meter-out circuits is corresponding, so that further explanations are unnecessary.

5 shows the wiring diagram of the Valvistor control block 60 with electrical (EP) actuation of the pilot valves, wherein, for the sake of simplicity, only the branch assigned to the consumer connection B is shown. The only difference between the variants according to the 4 and 5 is that in the embodiment according to 5 - as I said - the pilot valves 4a . 4b and 4c . 4d (the latter not shown) are not hydraulically but electro-proportionally adjusted to the main cone 8th to lift the pressure medium flow control from its valve seat. The other hydraulic circuit is identical to the above-described embodiment, so that further explanations are unnecessary.

In 6 is a hydraulic circuit for supplying pressure to a linear consumer 58 or a rotary consumer, such as a hydraulic motor 70 shown. The control of the consumer takes place according to 3 via a valvistor control block 60 , which is hydraulically controllable in this embodiment, to actuate the consumer in the direction of a or b.

The respective control pressure PST is via a pilot control device 72 set that off in principle Pressure reducing valves consists of a joystick 74 are adjustable to lower the pressure of a control pressure supply to the respective required control pressure. The pilot control unit 72 can be designed so that the Valvistor control block is adjustable in a floating position and / or emergency lowering. The control oil supply takes place via a control pump 76 about which a control oil store 78 is charged to the supply pressure of, for example, 30 bar. In the control oil flow path to the control oil reservoir 78 is a check valve 80 arranged, which is a return flow in the direction of the control pump 76 prevented. The maximum supply pressure is via a pressure relief valve 82 limited. This maximum pressure is for example 30 bar. The pressure connection of the control pump 76 is via a supply line 83 with the input connection of the pilot control unit 72 connected. In this control oil flow path is another check valve 84 intended. The connection of the control oil reservoir 78 and the area downstream of the check valve 84 is via a storage line 86 connected, in which a storage switching valve 88 is arranged, which is biased in a closed position and can be brought electrically or by hand in an open position.

In the area between the two check valves 80 . 84 branches a UF line 90 which leads to a tank T. In this UF line 90 is a UF valve 92 arranged, which is biased by a spring into a blocking position and is acted upon by the supply pressure in the direction of an open position. In the closing direction, the pressure at port P of the valvistor control block also acts 60 that has a channel 94 is tapped.

In the case where, for example, the consumer 58 . 70 due to a pulling load leading, the pressure at port P of the control block sags 60 off, leaving the UF valve 92 is brought by the supply pressure in its open position and accordingly a control oil connection to the tank T is turned on. Accordingly, the supply pressure decreases, so that via the valvistor control block 60 the flow of pressure medium flowing away from the consumer is throttled and, accordingly, the pump is, so to speak, "non-positively" in operative connection with the respective consumer - an anticipation can thus be reliably prevented. Such a circuit also suppresses cavitation in the open and closed circuits.

7 shows a constructive design of the UF valve 92 , Accordingly, this has a housing 96 in which a valve spool 98 is guided axially adjustable. This is about a spring 100 biased against a front stop. The bias of the spring 100 can be via a spindle 102 be adjusted. The housing 96 is provided with a leakage port L, a control port YP, and an input port PST connected to the pilot oil supply.

An in 7 left end face of the valve spool 98 is from the pressure in a control room 102 against the force of the spring 100 applied. In this control room 102 affects the supply pressure, which has an internal channel 104 of the valve spool 98 is tapped at the input terminal PST. In the opposite direction, the pressure acts in a spring 100 receiving spring chamber 106 , which is in fluid communication with the control port YP. This one is over the channel 94 to the pressure port P of the valvistor control block 60 connected. This pressure usually corresponds to the pump pressure of the pressure medium supply of the consumer 58 . 70 ,

In a channel from the control port YP to the spring chamber 106 can a damping nozzle 108 and a check valve opening in the direction of the control port YP in parallel 110 be arranged, which is an outflow of control oil from the spring chamber 106 allows.

The valve spool 98 is executed with one or more tax grooves. These are designed such that in the illustrated basic position, a pressure medium connection from the input port PST to the tank-side port L is shut off. When leading the assigned consumer and thus a pressure drop in the spring chamber 106 (Pump pressure drops) becomes the valve spool 98 through the counter-acting control room 102 effective control pressure shifted in the direction of its open position, wherein the control groove 112 is designed so that when reaching the with 1 marked position the pressure medium connection between the terminals PST and L is gradually opened and only when the position 5 a faster control of the opening cross-section between PST and L takes place.

The regulation of the supply pressure is thus damped in the event of a consumer advancing.

8th shows a lid of a valvistor control block 60 according to 3 , being in this lid 114 the electro-proportional pilot control of the associated main stage (see 1 ) is integrated. It is a pilot control of a Valvistor in meter-in circuit, as they are based on 1 is explained. One recognizes in the sectional representation according to 8th that has a proportional magnet 116 actuated pilot valve 4 , whose cone 32 over the spring arrangement 34 against the seat 36 is biased. The output port B of the pilot valve 4 is over a channel 118 with the Input port P '' of the associated pressure compensator 6 connected, which largely the same structure as the pressure compensator 6 in the embodiment according to 1 Has. At the pilot valve 4 according to 8th are the spring space and the space in which the plunger 120 of the proportional magnet 116 dips in and with the cone 32 is connected, via an axial channel 122 connected to each other, which in turn is in fluid communication with the tank, so that the end faces of the cone 32 relieved of pressure.

Such a lid, for example, readily replaced with a lid, in which a hydraulic control of the main stages of the meter-in Valvistoren is integrated.

9 shows a corresponding lid 124 , in which the feedforward control of a valvistor in meter-out circuit is integrated. The structure of the pilot control corresponds to the circuit according to the embodiment in FIG 2 , Accordingly, in the lid 124 the meter-out pressure compensator 6 and the electroproportional adjustable pilot valve 4 integrated. The adjustment of the pilot valve 4 takes place, as explained, via a proportional magnet 116 against the force of the spring assembly 34 about which the cone 32 against his seat 36 is biased. As in the embodiment according to 2 is the bias of the DW spring 44 via an adjusting device 56 adjustable with spindle.

A constructive explanation of the pilot valves and the pressure compensators of the lid according to the 8th and 9 is not necessary, since these are essentially the embodiments according to the 1 respectively. 2 correspond.

The 10 and 11 show a concrete solution of a valvistor control block 60 with hydraulic pilot control, ie the embodiment according to the 10 and 11 is essentially the same as in 4 illustrated circuit.

In a housing 126 of the Valvistor control block 60 are the basis of the circuit according to 4 explained meter-in-main stages 2a . 2c and the corresponding meter-out main stages 2 B and 2d integrated, while the pilot controls with the pilot valves and the pressure compensators are each included in a lid. These covers are in the embodiment according to 10 with the reference numerals 114a . 114c (Meter-in) and 124b . 124d (Meter-out). 11 shows a side view from the left (view after 10 ) on the two lids 124d . 114c , You can see in this view, perpendicular to the plane in 10 arranged meter-in pilot valve 4c (please refer 4 ), whose adjustment takes place via the control pressure at the control terminal X. The lid 124d according to 11 Also includes the meter-out pilot valve 4d , whose basic construction is the meter-out pilot valve 4 out 2 equivalent. Again, the adjustment of the pilot valve 4d via the control connection X.

Perpendicular to it are according to 10 the meter-in pressure compensators 6a . 6c (the latter only partially visible) provided. In the covers 124b . 124d are in a similar way the meter-out pressure compensators 6b and 6c (the latter again only partially visible) formed. The construction of the meter-in and meter-out pressure compensators was based on the 1 respectively. 2 explained, so that reference to these statements can be dispensed with a detailed description.

As based on 2 is explained in the main cone 8b . 8d the meter-out main stages 2 B . 2d each the suction valve 54b respectively. 54d integrated with pressure limiting function. Continue to be visible in 10 are the connections T, LS and P of the housing 126 and the L connectors integrated into this case 126 are also the two load-holding valves 28a . 28c and the check valves 30a . 30c the LS line integrated.

As explained, the lids can 114 . 124 be relatively easily replaced with the hydraulic pilot control against the above cover with electroproportional pilot control.

12 shows a circuit diagram of another embodiment of a Valvistors 1 , the basic structure of the Valvistor with meter-in circuit from the 1 and 4 equivalent. The only significant difference is that in the embodiment according to 12 the main stage 2 and the pilot level 4 in a common cartridge 128 are arranged while the pressure balance 6 (Compensator) is designed as an extra component. Both components can then be used as a cartridge valve in the Valvistor control block.

The circuit explained below is preferably used for supplying pressure medium to a single-acting consumer, wherein the in 12 shown electro-proportional control is a "lifting" of a load. As explained, are in the cartridge 128 the main stage 2 and the electroproportionally actuable pilot valve 4 arranged. The main stage 2 is in the closing direction over the spring 16 and the one about the tax people 18 tapped pressure applied to the pressure port P. In the opening direction, the pressure also acts on the pressure connection P and on the seat or outlet-side annular end face explained in the introduction (see reference numeral 130 in 1 ) the pressure at the output port A of the main stage, ie the pressure in the working line 12 to the consumer. The main cone 8th the main stage 2 is with a surface difference executed, wherein the area ratio i is again 1: 1.138.

That too in the cartridge 128 integrated pilot valve 4 is, as I said, electroproportional over the proportional magnet 116 adjustable in the opening direction and the spring arrangement 34 acted upon in the closing direction. Furthermore, in the opening direction, the pressure acts on the input port P 'of the pilot stage 4 , This pressure acts on the input terminal side annular shoulder 62 of the cone 32 (see also 1 ).

The output terminal B of the pilot stage 4 is to the input port P '' of the pressure compensator 6 connected. This is in the illustrated embodiment with the same area ratio as the main cone 8th the main stage 2 executed (i = 1: 1,138). The pressure balance 6 is from the pressure at the input port P of the cartridge 128 and from the pressure at the outlet Y of the pressure balance 6 acted upon in the closing direction (see annular shoulder 62 in 1 ). The pressure compensator spring acts in the opening direction 44 and the pressure at the input port P ", which is above the throttle cross-section 64 (see also 1 ) is tapped.

13 shows a concrete embodiment of a Valvistoranordnung 1 according to the embodiment in 12 , As explained, the main stage 2 and the pilot level 4 in a cartridge 128 (also called cartridge) taken in a stepped bore 132 a valve block 134 , For example, the Valvistor control block are screwed. In the stepped bore 132 open in the radial direction of the or the working ports A (B) and in the axial direction of the pressure port P. In the lower part of the cartridge 128 is the main stage 2 with the main cone 8th integrated, over the spring 16 with its seat-side annular end face 130 against in the cartridge 128 trained seat 14 is biased. The ring end face 130 is the pressure at the working port A and the in 13 bottom face of the main cone acted upon by the pressure at the working port P. About the tax people 18 and the axial bore 22 is the input terminal side area of the main stage 2 with the control room 20 connected in which the spring 16 is arranged. As explained, the area ratio between the end surface portions acted upon in the opening direction by the input pressure and the end surface portions acted upon in the closing direction with the input pressure i = 1: 1.138.

The electroproportional actuated pilot stage 4 is in the illustration according to 13 above the main level 2 in the cartridge 128 added. Here is the cone 32 over the spring arrangement 34 in rest position against the pilot seat 36 biased. An axial projection of the cone 32 is in operative connection with the plunger 120 of the proportional magnet 116 , so that when energizing the proportional magnet 116 the cone 32 from the valve seat lifts, leaving the control room 20 to the output terminal B of the pilot stage 4 connected, in turn, via a cartridge channel 135 is connected to a control terminal X of the cartridge.

This control port X is connected via a control block-side channel to the input port P "of the pressure compensator 6 connected. This is also available as a cartridge valve with a pressure compensator cartridge 136 Running in a stepped bore 138 of the block 134 is screwed. As mentioned, the pressure balance is 6 in its rest position via the DW spring 44 biased towards its open position. In this direction also acts the pressure at the input port P '', which has a throttle cross-section 64 in the DW piston 42 is tapped. In the closing direction, the pressure acts on the pressure connection P of the valvistor 1 passing the pressure control line 48 is tapped. An output port Y of the pressure compensator 6 then leads back to the stepped bore 132 and is in fluid communication with the working port A. The solution shown is very compact and can be realized with minimal space in a control block.

14 shows the circuit diagram of a valvistor 1 for a meter-out circuit, in turn, the main stage 2 , the pilot level 4 and the provided with a meter-out circuit suction valve with pressure limiting function 54 in a cartridge 128 are integrated. The pressure balance 6 is also designed in cartridge design as a separate component. According to the comments on the 2 and 4 is the Valvistor 1 arranged at a meter-out circuit in the flow from the working port A of the consumer to the tank T (or even in a closed circuit). Incidentally, the construction corresponds to the embodiments described above, so that further explanations are unnecessary.

15 shows a concrete solution of the valvistor 1 out 14 in cartridge construction. As in the embodiment according to 13 are the main level 2 and the pilot level 4 essentially coaxial over each other in the cartridge 128 taken in turn, in the stepped bore 132 is screwed. The tank or drain port is axial and the consumer port is radially formed.

The pressure balance 6 is in turn in a pressure compensator cartridge 136 taken in a stepped bore 138 of the block 134 is screwed. As in the embodiment according to 10 explained, is the suction valve with pressure limiting function 154 with the pressure relief valve 140 and the suction valve 142 in the main cone 8th integrated. In all embodiments, via the pressure relief valve 140 the pressure to be limited to about 350 bar or the like. As explained above, the main level is 8th with an area ratio i = 1: 2,284. This area ratio is also with the pressure balance 6 realized.

Their DW pistons 42 is applied according to the meter-out circuit of the consumer pressure at port A in the closing direction, via the Out control channel 47 is tapped. In the same direction acts on the ring end face 62 of the DW piston 42 the pressure at the output port Y. The force of the DW spring acts in the opening direction 44 and the pressure at the input port P ", which is above the throttle cross-section 64 is tapped.

The structure of the pilot stage 4 corresponds to that of the embodiment described above, so that further explanations are unnecessary.

16 shows a circuit in which the function according to the embodiments of the 12 . 13 and 14 . 15 in a valvistor arrangement 1 are integrated. Thereby are a single main stage 2 and one of these associated pilot stage 4 for the lifting and lowering function (meter-in / meter-out) one pressure compensator each 6a . 6b assigned. main stage 2 and pilot level 4 are in turn in a common cartridge 128 recorded while the two pressure compensators 6a . 6b are each designed as a cartridge valve in the manner described above. The Valvistor 1 with meter-in and meter-out function is a lift / lower valve, hereinafter simply valve 144 called upstream, via which the depending on the direction of flow as an inlet or end connection effective connection P of the cartridge 128 with the pressure medium source P or the tank T is connectable. This valve 144 can be operated electrically or hydraulically.

Also in this embodiment, the main stage 2 performed with an area ratio that is in the range between the two above-described area ratios. In the concrete case, the area ratio of the main cone is i = 1: 2. The DW pistons of the two pressure compensators 6a . 6b are formed accordingly with a surface ratio i = 1: 2. Since the basic elements correspond to those of the embodiments described above, only the additional or differing components will be discussed below.

Such is in the control channel section, over which the main cone 8th the main stage 2 is acted upon in the closing direction, an effective in the direction of the port P check valve 146 intended. A corresponding check valve 148 is executed in the control channel, via which the aforementioned, effective in the opening direction end face portions of the main cone 8th with the pressure at port A ( 16 ) are acted upon.

Also in the tank control channel 68 , which is the outlet port Y of the dip pressure compensator 6b with the entrance of the valve 144 connects, is a check valve 150 intended. The input P '' of the lowering pressure compensator 6b is via a control channel 152 with the control oil flow path between the output port B of the pilot stage 4 and the input port P "of the lift-pressure balance 6a connected. In the area downstream of this branch is another check valve 154 arranged. The latter leaves a control oil flow to the connection P '' of the lifting pressure compensator 6a to. The two aforementioned check valves 146 . 148 open respectively in the direction of the effective in the closing direction end face of the main cone of the main stage 2 and the check valve 150 allows a control oil flow from port Y in the direction of port P (designation after 16 ).

Incidentally, the embodiment corresponds to the embodiments according to the 12 and 14 , so that further explanations are dispensable.

17 shows a concrete solution of the compact embodiment described above. Similar to the embodiments according to the 12 . 13 and 14 . 15 are the main level 2 and the pilot valve 4 coaxial with each other lying in the cartridge 128 integrated while the two pressure compensators 6a . 6b also as built-in valves, each with a pressure compensator cartridge 136a . 136b are executed in the corresponding stepped holes of the block 134 are screwed in.

As in the previously described embodiments, the pressure balance is 6b the meter-out branch with an adjustment 56 to adjust the bias of the DW spring 44b educated.

As already shown 16 explains, is the cartridge 128 with the main stage 2 and the pilot valve 4 the valve 144 upstream of the control of the pressure medium flow direction.

Incidentally, the embodiment corresponds to the above-described embodiment, so that further explanations are unnecessary.

18 shows a variant of the embodiment according to the 16 and 17 , in turn, in a cartridge the main stage 2 and pilot valve 4 are integrated, but only one pressure compensator 6 both the lift and the sink function (meter-in / meter-out) is assigned. The maximum pressure at the load port A is via the pressure relief valve 140 limited to a predetermined value, in the present case 350 bar.

The main stage 2 has in principle the same structure as in the previously described embodiments and is acted upon by the pressure at port P (input port when lifting) in the opening direction. This pressure also works in the spring 16 receiving control space, said control pressure on the control groove 18 is tapped. In the pressure medium flow path to the control groove 18 or to the control room is the check valve 146 intended. For the lowering function, the pressure at port A is correspondingly via a check valve 148 tapped and reported in the effective in the closing direction control room.

The pressure at port A also acts in the opening direction on the seat-side annular end face 130 of the main cone 8th (please refer 1 ). The pressure in the control room is in turn via the pilot valve 4 determined by means of the proportional magnet 116 is adjustable. At the in 18 variant shown are both executed without area difference end faces of the cone 32 subjected to the same pressure, the pressure in the control room 20 (please refer 1 ) corresponds. This pressure is via the pressure relief valve 140 limited, which opens in the lowering function when this pressure at the working port A a pressure medium connection to the tank T out, the valve 144 in the sink function is set to its illustrated home position. In the pressure medium flow path between the pilot valve 4 and the pressure balance 6 is the check valve 54 arranged. The inlet connection of this pressure relief valve 150 is via a pressure limiting line 156 with the control room of the main stage 2 Coupled to the input port P connecting control oil flow section. The pressure acts in the pressure limiting line 156 in the closing direction on the pilot valve, in the opposite direction, the same pressure acts via a branch line 158 is tapped so that the faces are pressure balanced. The pressure in the work line 12 is via a reporting line 155 tapped. The pressure to be limited is applied to a DW spring 162 set. The output of the pressure relief valve 140 is via a relief line 164 connected to the port P, so that when opening the pressure relief valve 140 Pressure medium from the work line 12 over the check valve 148 , the pressure limiting line 156 and the discharge line 164 can flow out to the low pressure side.

The pressure balance 6 is from the pressure downstream of the check valve 154 acted upon in the opening direction, said control pressure across the throttle cross-section 64 is tapped. In the opposite direction, the pressure acts on the outlet port Y of the pressure compensator 6 , This output port depending on the direction of flow over the in-control channel 46 another check valve 160 with the work management 12 connected is. In the closing direction, furthermore, the pressure at port P, which acts via the pressure control line, still acts 48 and the check valve 168 is tapped.

In the lift function (valve 144 switched), the pressure at the pressure port P acts via the pressure control line 48 on the pressure balance 6 in the closing direction. In the lowering function (valve 144 in the home position), this pressure, acting in the closing direction, is transmitted via the Out control channel 47 and the check valve 166 tapped.

The area ratio of the main stage 2 and the pressure balance 6 again i = 1: 2.

The embodiment according to 18 is even simpler than the embodiment described above and also includes a pressure relief valve for the lifting function.

19 shows a concrete solution of the circuit according to 18 , Accordingly, the main stage 2 and the pilot valve 4 coaxial with each other in the cartridge 128 added. In this cartridge are, for example, the check valves 146 and 148 integrated.

The bullet 128 with the main stage 2 and the pilot valve 4 is in the block 134 screwed. The pressure compensator associated with both the lift and the sink function 6 is also available as a cartridge valve with its pressure compensator cartridge 136 in the block 134 screwed, wherein in the control channel portion between the outlet port B of the pilot valve 4 and the input port P "of the pressure compensator 6 the check valve 154 is provided. The output port Y of the pressure compensator 6 is in the sink function via the tank control channel 68 and the check valve 150 connected to the then acting as a low pressure port P connection. In the lift function, the output Y is via the in-control channel 46 and the check valve 160 connected to the working port A.

The control connection X of the pressure balance 6 is in the lift function via the pressure control line 48 and a check valve disposed therein 168 connected to the work port P. In the lowering function, the control port X is above the check valve 166 and the Out control channel 47 connected to the working port A. The pressure relief valve 140 is in the block 134 integrated and is via the reporting line 154 acted in the opening direction. The pressure limiting line 156 flows into the control room 20 , while the output of the pressure relief valve 140 via the discharge line 164 connected to the terminal P.

In the 19 The solution shown is characterized by an extremely compact design with high functionality.

The 20 and 21 show the one 12 and 13 corresponding embodiment of a valvistor arrangement 1 in meter-in circuit, the only major difference being that the pilot valve 4 not electroproportional but hydraulically actuated by a control pressure a. This can, for example, as in the embodiment according to 6 be provided via a control pressure supply and via a pilot control device 72 be reduced to the respective required control pressure.

Otherwise, the circuit corresponds to 20 of those 12 , so that further explanations are dispensable.

21 shows the concrete solution, as far as possible according to the embodiment 13 corresponds, but instead of the proportional magnet 116 a cartridge lid 170 is formed with a control port PST, to which a control pressure a leading control line is connected. About this control pressure a, the in 21 overhead end face A3 are acted upon by the control pressure. The cone 32 is by the spring arrangement 34 against the pilot seat 36 biased, with an axial projection of the cone 32 in the cartridge cover 170 dips in and is acted upon by the spring force. In this area is also a leakage connection L in the cartridge lid 170 educated.

Otherwise, this corresponds to 21 illustrated embodiment as far as possible from that 13 , so that further explanations are dispensable.

The 22 . 23 show the corresponding valvistor arrangement 1 in meter-out circuit, this embodiment being virtually identical to that of 14 and 15 with the exception that in the latter embodiment, a elektroproportionale control of the pilot valve 4 takes place while in the embodiment according to the 22 . 23 a hydraulic control by means of a control pressure a is provided.

With reference to the comments on the embodiment 14 . 15 and features of hydraulic control according to the explanations to 21 can therefore with regard to the embodiment according to the 22 . 23 to dispense with further explanations.

In 24 is the meter in / meter out circuit according to 16 with hydraulically actuated pilot valve 4 shown. As explained above, this can aufsteuern a control pressure a from its spring-biased closed position to an inlet orifice to the downstream pressure compensator 6a . 6b to open.

25 shows a concrete solution in which, similar to the embodiment in 17 the main stage 2 and the pilot valve 4 coaxially lying one behind the other in a cartridge 128 are included in the block 134 is screwed in. The bullet 128 has a cartridge cover 170 whose function is based on the embodiment in 21 is explained.

The two associated pressure compensators 6a (Lifting) and 6b (Sinks) are also designed as cartridge valves and each in a cartridge 136a . 136b added.

The function corresponds to the embodiment according to 17 , so that further explanations are dispensable.

The 26 and 27 show the meter-in / meter-out circuit according to the 18 respectively. 19 However, instead of an electro-proportional control, a hydraulic control of the pilot valve 4 he follows.

27 shows the concrete solution, in turn, the main stage 2 and the pilot valve 4 in a cartridge 128 are arranged. The pressure compensator associated with both lifting and lowering operations 6 is also designed as a cartridge valve. The pressure medium flow direction is again via the valve 144 set, as in the embodiment according to 25 is switched hydraulically via a control pressure x.

28 shows a circuit diagram for the pressure medium supply of a double-acting consumer, such as a hydraulic cylinder. This circuit can be controlled by a single valvistor control block 60 be realized, which has at least one pressure port P, a tank port T and working ports A, B, which are connected via working lines with the corresponding pressure chambers of the consumer to actuate this.

The control block 60 in turn contains Valvistor components in the above-described design, according to the embodiment 28 two Valvistor modules according to the 18 . 19 can be used. As explained, these valvistors are designed in such a way that they allow operation in the meter-in and meter-out function for each working connection A, B and furthermore have a pressure-limiting valve for the outflowing pressure medium volume flow. These assemblies are shown in the illustration 28 with the reference number 1a and 1b characterized. According to the concrete solution in 19 For example, each assembly may be cartridge-type, with, for example, the main stage 2 and the pilot valve 4 in a cartridge and the associated pressure compensator 6 in another cartridge is inserted into the block. At the in 28 The solution shown is the control of the respective pilot valves 4a . 4b electro-proportional.

29 shows the same circuit with hydraulic control. In the pressure medium supply of two working ports A, B, the valve 144 be executed with a slightly extended functionality. In the embodiment according to the 28 and 29 this valve is designed with a middle position (0), in which the input terminal P of the respective Valvistoren 1a . 1b is connected to the tank connection T. In an adjustment in the switching position (a) of the input terminal P with a pressure medium supply, such as a pump 172 connected during the then acting as an output terminal terminal P of the other valvistor 1b connected to the tank T. When switching to the switching position (b) in the reverse manner, the terminal P of the valvistor 1b with the pump 172 and the terminal P of the other valvistor 1a connected to the tank - the hydraulic cylinder then moves accordingly.

According to the embodiment 28 will also be the valve 144 electrically operated. In the embodiment according to 29 takes place - as I said - the operation of the two pilot valves of Valvistoren 1a . 1b hydraulically. Accordingly, the switching valve 144 hydraulically operated. In the circuit according to the 28 . 29 are still two suction valves 54a . 54b provided, can be sucked through the pressure medium in a lead-ahead of the consumer from the tank T to the respective undersupplied port B.

The respective load pressure in the working lines 12a . 12b is via the LS check valves described above 30a . 30b tapped and reported in the load pressure line LS.

Of course, the other Valvistor constructions in the embodiments according to the 28 . 29 be used.

According to the embodiment 29 are accordingly the valvistors 1a . 1b according to the 18 . 19 used.

Otherwise, the circuits according to the 28 . 29 each other.

30 shows a concrete solution of the meter-in circuit according to 12 , In 13 is shown a concrete solution of this circuit, in which the main stage 2 and the pilot valve 4 in a common cartridge 128 are arranged. The assigned pressure balance 6 is in a separate cartridge 136 added. The embodiment according to 30 is compared to this variant further simplified by the fact that the pressure compensator 6 in the cartridge 128 is integrated, so that accordingly the main stage 2 , the pressure compensator 6 and the pilot valve 4 are arranged coaxially along the cartridge axis. Specifically, the pressure balance 6 in the main cone 8th the main stage 2 integrated, whereby the basic structure of the modules (main stage 2 , Pilot valve 4 and pressure balance 6 ), for example, the embodiment according to 1 equivalent.

In the control according to 30 is the pilot valve 4 electroproportional over the proportional magnet 116 actuated. Also in this embodiment, the area ratios at the pressure balance 6 and at the main stage 2 executed the same. The area ratio i = 1: 1.15. Similar to the embodiment in 13 the pressure at the input port P is via a bore 22 of the main cone 8th and the control groove (s) 18 with the control room 20 connected so that the inlet pressure also in the closing direction on the main cone 8th acts. Also in the closing direction, the weak spring acts 16 that the main cone 8th at rest against the seat 14 biases. The hole 22 However, not as axial bore as in the embodiment in 13 but designed as an oblique hole. Axially inside the main cone 8th is the DW piston 42 guided, whose end face A3 in the illustrated basic position in the bore 22 protrudes into it and thus is also acted upon by the pressure at port P. The DW piston 42 is due to the power of the DW spring 44 acted in the opening direction. In the same direction, the pressure acts upstream of the pressure compensator 6 that's about the throttle area 64 is tapped. The input port P '' of the pressure compensator 6 is over at least one axially parallel longitudinal groove 176 with a circumferential groove 178 the cartridge 128 connected, which is also in fluid communication with the output port B of the pilot valve 4 stands. The output port Y of the pressure compensator 6 is over a radial bore 180 with the respective working connection A (B) connected. The DB spring 44 is on a cap 182 supported in the bottom of the main cone 8th screwed in, on which also the spring 16 attacks.

30a shows a greatly simplified section through the main cone 8th the main stage 2 , You can see it in an axial bore 184 guided DW pistons 42 , At the outer circumference of the main cone 8th is an anti-twist device 186 provided, for example, a ball in a form-fitting manner in a securing groove 188 at the main cone 8th and in a corresponding securing groove 189 the cartridge 128 intervenes. In the sectional view according to 30a is also in the cross section to the viewer towards increasing tax groove 18 shown. In the illustration according to 30a is also an additional longitudinal groove 176 ' shown diametrically to the longitudinal groove 176 runs and in fluid communication with the circumferential circumferential groove 178 the cartridge 128 stands.

Incidentally, the embodiment corresponds to the embodiment according to 13 , so that further explanations are dispensable.

31 shows a corresponding solution for the meter-out circuit according to 14 , In the cartridge 128 are therefore the main level 2 , the pilot valve 4 and the pressure balance 6 similar to the embodiment according to 30 added. The pressure medium flows to the main stage 2 via the working port A (B) to and over the axial port T towards the tank. The main cone 8th is over the spring 16 against his seat 14 biased, wherein in the control room in the idle state, the pressure at the port A, B acts, via the control grooves 18 is tapped. In the opening direction acts on the main cone 8th the pressure at the tank connection T and on the seat-side annular end face 130 acting pressure at port A.

The input P of the pilot valve 4 opens to the control room 20 , The output B of the pilot valve is over in the cartridge 128 trained channels with the longitudinal groove 176 at the main cone 8th connected, in turn, to the input port P '' of the pressure compensator 6 opens, whose DW pistons 42 similar to the embodiment according to 30 in the main cone 8th is guided. The face A3 of the DW piston 42 is via an out control channel 47 forming radial passage with the pressure at the input terminal A in the closing direction acted upon. In the same direction acts on an annular shoulder of the DW piston 42 the pressure at the outlet port Y of the pressure compensator 6 , The DW spring acts in the opening direction 44 , in turn, on a cap 182 is supported. Furthermore, in the opening direction, the pressure at the inlet connection P "also acts via the throttle cross-section 64 is tapped.

The basis 14 explained pressure relief valve 140 and the suction valve 142 is in the block 134 integrated. The input connection of the pressure relief valve is located here 140 in fluid communication with the control room 20 , in which the pressure at port A is effective at rest. The inlet of the suction valve 142 is at the circumferential groove 178 the cartridge 128 connected, which is in fluid communication with the terminal T.

32 shows a circuit diagram for the pressure medium supply of a single-acting consumer via a Valvistor 1a in the above-described meter-in circuit and a drain-side valvistor 1b in the above-described meter-out circuit. In this case, for example, in a control block, the above-described compact cartridges are used, in which the main stage 2a . 2 B , the pilot valve 4a . 4b and possibly also the pressure balance 6a . 6b are integrated. The drain-side valvistor 1b is also in the manner described above with a pressure relief valve 140 and a suction valve 142 executed. In the working line to the consumer port A1, B1 is a load-holding valve 28 provided for leakage-free support of the load. The actuation of the pilot valves 4a . 4b takes place electroproportional in these embodiments, for example via a joy stick, via which an electronics is controlled to control the consumer to generate an electrical control signal a, b.

The inlet-side connection is according to the embodiment 32 provided with the reference A, B. Otherwise, the circuit corresponds to 32 as far as possible from those 5 ,

33 shows a variant of the meter-in / meter-out circuit according to 32 , being from the work line 12 to the consumer port A1, B1 downstream of the load-holding valve 28 a storage line 190 branches off, in which a storage valve 192 is arranged, the output terminal to a hydraulic accumulator 194 connected. The storage valve 192 is also designed to be electro-proportionally adjustable and can be from a basic position in which the pressure fluid connection of the hydraulic accumulator 193 to the work management 12 is sealed off leak-free, but a pressure fluid flow to the hydraulic accumulator 193 is possible to adjust in a flow direction enabling both passage position, wherein the adjustment is proportional, so that for example via the hydraulic accumulator 193 the pressure medium supply of a consumer can be supported. This may be necessary, for example, in the event of a shortfall of the consumer. By such a circuit (RSM circuit) a sagging of a consumer when switching can be reliably prevented.

34 finally shows a variant of the meter in / meter out circuit 32 , being in one of the working line 12 branching work line 194 , which leads to a further connection of a double-acting consumer (A2, B2) an electro-proportionally adjustable rapid traverse valve 196 is arranged. In his spring-biased rest position is this rapid-action valve 196 shut off. To set a rapid traverse (regeneration), the rapid traverse valve 196 be controlled so that, for example, pressure medium, an annular space of a hydraulic cylinder, which is supplied via the port A2, B2 with pressure medium can be connected to the piston-side pressure chamber of the hydraulic cylinder, which is supplied via the port A1, B1 with pressure medium, so that from the Annulus pushed-out pressure medium quantity is fed directly to the piston-side pressure chamber, which adds up to the flowing over the port A, B pressure medium quantity.

Of course, the variants according to the above-described embodiments may also be provided with a hydraulic control.

As already explained, the pressure medium can be supplied via a pump, for example a variable displacement pump, wherein the pivot angle of the variable displacement pump is adjusted electrically, for example via a joy stick and an associated electronics. The actuation of the valve assemblies is then also electroproportional via this electronics. The variable displacement pump can be controlled purely electronically or as a function of the highest load pressure of the driven consumers. Such pump controls are known in the art. In a purely electrical control of the pump and also the described Valvistoren can be dispensed with a pressure relief valve and a Nachsaugventil.

If, for example, a valvistor control block with load-pressure-dependent control of the pump for supplying pressure medium to a double-acting consumer is used, the meter-invalve arrangement located in the inlet is characterized in that in the pilot control branch through the pilot valve 4 and the downstream pressure balance 6 a current regulator is formed, which is a load pressure independent control of the main stage 2 allows. There is the possibility to perform a rapid traverse over the above-described directional control valve. A pressure-dependent quick opening is possible. The main stage is hydraulically, electro-proportionally or mechanically controlled via a lever. A LUDV function adjusts automatically in the inlet.

The meter-out Valvistoranordnung is also characterized by the load pressure independent actuation of the main stage. Furthermore, a Nachsaugfunktion and secondary valve functions can be realized. The above-described pressure relief valve allows a shockless function, which is largely independent of viscosity.

The lowering brake valve function prevents the consumer from leading. The Valvistor arrangement can also be formed with a driving brake valve function for a drive and slewing drive.

By the electrical control of the pilot valves, a floating position can be set to a double-acting consumer with minimal effort.

As described, a regeneration function can also be implemented relatively easily. The control can in turn be hydraulic, electro-proportional, purely electrical or mechanical. Even with the meter-out valvistor, a LUDV function is automatically guaranteed in the process.

35 shows a wheel loader circuit in Valvistorbauweise, via simple valvistors of the type described above, a boom with two hydraulic cylinders 198 . 200 , a shovel with a hydraulic cylinder 202 and an optional consumer, such as an optional attachment with a hydraulic cylinder 204 is operable. The pressure medium supply takes place via a variable displacement pump 172 , which depends on the control signal of a pilot control device 72 can be controlled by means of a joystick 74 is adjustable. In the present case, it is a circuit in which both the pump and the valvistors are controlled in an electro-proportional manner.

The control of the optional consumer via another pilot control device 206 and an associated therewith control, such as a joystick 208 , A swivel angle of the variable displacement pump 172 is via a Schwenkwinkelverstelleinrichtung 210 adjusted electrically proportional, wherein the control signal at port p of the pilot control device 206 is tapped. The speed of the variable displacement pump 172 is via a speed sensor 212 detected and via a signal line to a port n of the pilot control devices 72 . 206 reported.

Accordingly, the swing angle and the rotational speed of the variable displacement pump in response to the pilot units 72 . 206 Adjusted pressure medium requirement adjusted.

As explained, the boom is actuated by two hydraulic cylinders connected in parallel 198 . 200 , in turn, via valvistors of the as described above, for example, with meter-in / meter-out function, as exemplified in 3 are shown, wherein in this embodiment, a hydraulically operated Valvistor is shown, while in the circuit according to 35 , as mentioned, electrically proportional valvistors 60a . 60b be used. The Valvistor control blocks 60 are each mounted on the associated hydraulic cylinders. The pressure medium connection of the bottom-side pressure chambers of the two hydraulic cylinders 198 . 200 of the boom with the pump 172 or the tank T via the Valvistor control block 60b , while the pressure fluid connection of the piston rod-side annulus with the pump 172 or tank T via the valvistor control block 60a is controlled. In this case, the setting of the opening cross-section of the associated pilot valves takes place 4 (see above-described circuits) via the proportional solenoids a1, b1, a2, b2, via the electrical pilot control device 72 be controlled. The Valvistor control block 60a is similar to the embodiment according to 34 executed with a rapid traverse valve whose proportional solenoid e in 35 is indicated. To set the rapid traverse (regeneration), the proportional solenoid e is energized and thus the rapid traverse valve controlled, so that the pressure medium from the annulus directly into the bottom pressure chamber of the two hydraulic cylinders 198 . 200 is pushed out and thus summed to the inflowing of the pump pressure medium.

The Valvistor control block 60b is with an RSM valve according to 33 executed, the proportional magnet is denoted by the reference r. This RSM valve can also be controlled via the electronic pilot control unit 72 be adjusted proportionally to a pressure medium connection to the hydraulic accumulator 193 to raise proportionally. Regarding the function of the RSM valve (storage valve 196 ) is for the sake of simplicity to the description of 34 directed.

The control of the hydraulic cylinder 202 to operate the blade takes place in a similar manner via two Valvistor control blocks 60c . 60d , each with meter-in / meter-out function but with no rapid traverse or RSM valve.

Also provided for operating the optional consumer hydraulic cylinder 204 that is via the pilot control unit 206 is controlled in a corresponding manner with proportionally adjustable Valvistor control blocks 60e . 60f executed, whose proportional solenoids at signal terminals a2, b2, a1, b1 of the electrical pilot control device 206 are connected.

As further in 35 shown, has the variable displacement pump 172 a primary pressure relief valve 214 , via which the system pressure at the pressure connection of the pump is limited to a maximum value, for example 350 bar. In a tank line is a preload valve with suction valve 216 arranged, via which a pressure fluid connection to the tank T is turned on only when a certain minimum pressure, for example 5 bar is exceeded. In a bypass line, a check valve is arranged, which allows the Nachsaugfunktion.

36 shows a corresponding circuit for a wheeled excavator whose chassis to a designed as a variable displacement hydraulic motor 218 has its connections via a dual valvistor control block 60g with the pump 172 or the tank T are connectable. The electroproportional control of the Valvistor control block 60g takes place - similar to the in 6 illustrated embodiment - again via an electronic pilot control device 72 with a joystick 74 , The hydraulic motor (s) of the landing gear 218 are adjustable, with the tilt angle on the pilot unit 72 is electrically proportional adjustable.

A slewing gear of the wheeled excavator has another hydraulic motor 220 , which is designed as a constant-speed motor and its connections via a dual valvistor control block 60h with the pump 172 or the tank T are connectable. The activation of this valvistor control block 60h via another pilot control device 206 , About this will also be two single-valvistor control blocks 60i . 60j a hydraulic cylinder 222 actuated to actuate a handle of the wheel loader, so that depending on the direction of movement of the stem, a bottom-side pressure chamber or a ring-side pressure chamber with the pump 172 and the other pressure chamber is connected to the tank T. The Valvistor control block 60j is additionally designed with a float valve, which is connected via port e of the pilot control unit 206 is controlled.

The two valvistor control blocks 60g . 60h are also designed with a brake valve or a service brake valve.

The operation of a boom with the hydraulic cylinders 198 . 200 via a third electronic pilot control unit 224 , via which the movement of a spoon of the wheeled excavator can be controlled. The operation of the spoon by means of a hydraulic cylinder 226 , whose bottom-side pressure chamber and its annulus via Valvistor control blocks 60k . 60l in the manner described above with the pump 172 or the tank are connectable.

The pressure medium supply of the two bottom pressure chambers of the two hydraulic cylinders 198 . 200 the boom takes place via valvistor control blocks 60f . 60d , while the pressure medium supply of the piston rod side annular spaces via a two hydraulic cylinders 198 . 200 common valve arrangement, preferably also a Valvistor control block 60m is controlled. The control of the three valvistor control blocks 60f . 60d . 60m takes place, as mentioned above, via the electronic pilot control device 224 , The swivel angle of the pump 172 will depend on the at the pilot units 72 . 206 . 224 adjusted control signals via the Schwenkwinkelverstelleinrichtung. Also in this embodiment, the pump 172 a primary pressure relief valve 214 and a bias / suction valve 216 assigned.

37 shows a hydraulic circuit diagram of a crawler excavator, the slewing gear, stem, left chassis, right chassis, spoon and boom are in turn connected via valvistor arrangements with a pressure medium source or a pressure medium sink. The slewing gear is designed with a brake valve, while the stem, similar to the embodiment described above, is designed with a floating position. The two running gears are each provided with driving brake valves. The boom is similar to the embodiment described above with a regenerative braking system (RBS) running.

As in the embodiment according to 36 , the control of the Valvistor control blocks takes place 60i . 60j of the stalk and the Valvistor control block 60h of the slewing gear via an electronic pilot control unit 206 while every landing gear hydraulic motor 218R . 218l a valvistor control block 60gr respectively. 60gl is assigned, in turn, via an electronic pilot control device 206r respectively. 206l be controlled.

The pressure medium supply of the boom and the spoon is controlled as in the embodiment described above, so that further explanations are unnecessary.

In contrast to the above-described embodiment, the hydraulic motor 220 of the slewing gear, the hydraulic cylinder 222 the handle and the adjustable hydraulic motor 218l of the left landing gear a pump 228 and the other consumers, ie the hydraulic motor 218R the right landing gear, the bucket and the boom another pump 172 assigned, the pivot angle is in turn adjusted in response to the set on the respective electronic pilot control devices control signals to cover the pressure medium requirement.

According to the wiring diagrams in the 35 . 36 . 37 the adjustment of the pumps takes place 172 . 228 electro-proportional. In the 38 . 39 . 40 Corresponding embodiments are shown in which, however, the control of the variable displacement pumps 172 . 228 hydraulically. Otherwise, the embodiments correspond to the 38 . 39 . 40 those in the 35 . 36 . 37 (in this order), so that only the essential differences are discussed and, moreover, reference can be made to the previous remarks.

In contrast to the above-described embodiments, the actuation of the Schwenkwinkelverstelleinrichtung thus takes place 210 not electrically but hydraulically, wherein in an adjustment of the pump pressure at port G is applied and in the other adjustment of the highest load pressure of the pump via the 172 supplied consumer. This is via a LS line 230 tapped, which has a current regulator with a shutter 232 and a pressure balance 234 is connected to the tank T, so that the flowing over the LS line to the tank T control oil flow load pressure is independent constant. The control pressure for adjusting the Schwenkwinkelverstelleinrichtung upstream of the aperture 232 tapped.

The same applies to the wheeled excavator circuit according to 39 ,

In the crawler circuit according to 40 that in the basic principle of the circuit according to 37 corresponds, the swivel angle adjustment of both pumps 228 . 172 in a similar way. Ie. the pump 172 is as in the embodiments described above according to the 38 . 39 running, with the highest load pressure of the consumer boom, bucket, chassis right over the LS line 230 tapped and the Schwenkwinkelverstelleinrichtung 210 is reported while the highest load pressure on the chassis left, stem or slewing on another LS line 236 is tapped and upstream of a shutter disposed therein 238 tapped and the Schwenkwinkelverstelleinrichtung 210 ' to be led. In all embodiments according to the 38 . 39 . 40 is similar to the embodiments described above via a Drehzahlaufnehmer 212 . 212 ' the speed of the respective pump 172 . 228 recorded and reported to the associated pilot control devices.

Disclosed is a Valvistoranordnung with a main stage, which is associated with an adjustable throttle forming pilot valve, which is followed by a pressure compensator.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 0541338 B1 [0002]
• EP 0079870 B1 [0002]
• DE 10124154 A1 [0002]

Claims (16)

Valvistor arrangement with a main stage ( 2 ), whose valve body is acted upon by the pressure in a control chamber in the closing direction and with a pilot control branch, in which a pilot valve ( 4 ) and an associated pressure balance ( 6 ), characterized in that the pressure compensator ( 6 ) downstream of the pilot valve ( 4 ) is arranged. Valve arrangement according to claim 1, wherein the pilot valve ( 4 ) is a continuously adjustable throttle. Valve arrangement according to claim 2, wherein the pilot valve ( 4 ) is electrically, electro-proportionally, hydraulically or manually adjustable. Valve arrangement according to one of the preceding claims, wherein the pressure compensator ( 6 ) from the pressure upstream of the main stage ( 2 ) is acted upon in the closing direction and the pressure upstream of the pressure compensator in the opening direction. Valve arrangement according to claim 4, wherein an output terminal of the main stage ( 2 ) is connected to low pressure and the pressure compensator ( 6 ) opens to low pressure. Valve arrangement according to claim 4, wherein an output terminal of the main stage ( 2 ) is connected to a working line to the consumer and the pressure compensator ( 6 ) opens to the working line. Valve arrangement according to one of the preceding claims, wherein the main stage ( 2 ) is designed as a 2-way valve whose valve body in the opening direction from the pressure upstream of the main stage 2 is acted upon and with a control channel between the control chamber and a pressure chamber which is acted upon by the pressure acting in the opening direction. Valve arrangement according to one of the preceding claims, wherein a valve body of the main stage ( 2 ) is executed with a surface difference. Valvistoranordnung according to claim 8, wherein also a valve body of the pressure compensator ( 6 ) is carried out with an area ratio, wherein the surface difference at the pressure balance ( 6 ) and at the main stage ( 2 ) is substantially the same. Valve arrangement according to one of the preceding claims, wherein the main stage ( 2 ) and the pilot valve ( 4 ) in a cartridge ( 128 ) are arranged. Valvistor arrangement according to claim 10, wherein also the pressure balance ( 6 ) in the cartridge ( 128 ) is arranged. Valvistor arrangement according to claim 11, wherein the pressure compensator ( 6 ) into the valve body of the main stage ( 2 ) is integrated. Valvistoranordnung according to any one of the preceding claims, wherein the pressure medium supply, for example, a double-acting consumer with two flow directions a main stage ( 2 ), a pilot valve ( 4 ) and each flow direction a pressure balance ( 6 ) assigned. Valvistoranordnung according to any one of the preceding claims, wherein the drain side, a pressure relief valve ( 140 ) and / or a suction valve ( 142 ) is provided. Valve arrangement according to one of the preceding claims, with a storage valve ( 192 ). Valve arrangement according to one of the preceding claims, with a rapid-action valve ( 196 ).

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