EP0845602B1 - Electrohydraulic control device - Google Patents

Description

State of the art

The invention is based on an electro-hydraulic control device for controlling the volume flows for a hydraulic Actuator depending on the electrical input signals on the proportional magnet according to that in the preamble of claim 1 specified genus.

Such an electrohydraulic control device has already been developed proposed after the older, unpublished patent application 195 22 746.8, with two such control devices to one double-acting control valve are connected. A single one Control device works with a solenoid operated Slider with which a 4/2 function is displayed. At the deflection of the slide is a volume flow from the Pump passed to the servomotor, this feed flow over a slide valve is guided; at the same time that of Actuator coming volume flow led to the return, whereby this drain flow is controlled by an unlockable seat valve becomes. The one-piece, as the main control element working slide is here for both valve functions provided at the same time. The power of the proportional magnet is done with the help of a hydraulic sequence control increasingly transferred to the slider. With this design the slider can either be on the inflow stream or dependent on the discharge current coming from the servomotor be adjusted by the electric current. The other volume flow arises according to the tolerances of the control edges of the slide and the housing. It can now be in may be a disadvantage in some cases, especially automatic ongoing control processes, so that not all Volume flows depending on the electrical current are known are.

Furthermore, DE 44 46 143 A1 is an electrohydraulic one Proportional valve known, the one operated by a magnet Control spool via a preloaded control spring on an adjusting screw, which is supported by a worm gear is fine adjustable. For setting the flow characteristic this proportional valve can the control spring in a simple and precise way with different strength be biased. However, this proportional valve points no 4/2 function.

Advantages of the invention

The electrohydraulic control device according to the invention has with the characterizing features of claim 1 in contrast the advantage that they are for precise control processes suitable because the overlaps of the control edges for both volume flows are adjustable. Despite the design of the control device for a 4/2 function and the combination of Seat valve and slide valve can be adjusted here two characteristic curves occur; the disturbing influence of Tolerances in control processes can thus be largely avoided turn off. With the adjustment devices can with this Control device also the control sequence for the two control edges to get voted. The control device builds relatively simple and compact and suitable for precise control operation.

By the measures listed in the subclaims advantageous developments and improvements in the claim 1 specified electro-hydraulic control device possible. A particularly advantageous embodiment results itself according to claim 2, since this assignment is a fast and exact adjustment allowed. It is also favorable to the control device to train according to claims 3 to 9, whereby a directly controlled valve design is made possible to a compact control device with easily accessible Setting options leads. Are also useful Training according to claims 10 to 26, whereby pilot-controlled Valve designs are possible that vary Allow mounted slide axes. The statements lead according to claims 10 to 12 to relatively simple and compact control devices that can be manufactured inexpensively are and are easily adjustable. Are advantageous further embodiments according to claims 13 to 15, which a Control device with a small footprint results because the Control elements of seat valve and slide valve directly are slidably guided in the longitudinal bore. In the executions according to claims 16 to 22, it is advantageous if the valve carrier assigned to the poppet valve directly in the longitudinal bore can be arranged. It is advantageous further an embodiment according to claims 23 to 24, whereby also the pilot operated seat valve via a sequence control can be operated. An extremely inexpensive and simple construction results according to claim 27, which with few components are needed and relatively easy to manufacture is. Further advantages result from the remaining claims, the description and the drawing.

drawing

Figur 1

einen Längsschnitt durch ein erstes Ausführungsbeispiel einer elektrohydraulischen Steuervorrichtung in direktgesteuerter Bauweise in vereinfachter Darstellung,

Figur 2

als zweites Ausführungsbeispiel der Erfindung einen Längsschnitt durch eine elektrohydraulische Steuervorrichtung in vorgesteuerter Bauweise in vereinfachter Darstellung,

Figur 3

einen Teilschnitt nach III-III in Figur 2, und die

Figuren 4 bis 6

jeweils Längsschnitte durch eine dritte, vierte bzw. fünfte Ausführungsform der Steuervorrichtung.

Five embodiments of the invention are shown in the drawing and explained in more detail in the following description.
Show it:

Figure 1

2 shows a longitudinal section through a first exemplary embodiment of an electrohydraulic control device in a directly controlled construction in a simplified representation,

Figure 2

as a second exemplary embodiment of the invention, a longitudinal section through an electrohydraulic control device in a pilot-controlled design in a simplified representation,

Figure 3

a partial section according to III-III in Figure 2, and the

Figures 4 to 6

longitudinal sections through a third, fourth and fifth embodiment of the control device.

Description of the embodiments

1 shows a longitudinal section through a first electrohydraulic Control device 10, which acts as a 4/2 solenoid valve is executed. The control device 10 consists of a Seat valve 11 and a slide valve 12, the control members coaxially in a longitudinal bore 13 of a housing 14 are arranged one behind the other and by a proportional magnet 15 are operated. The control device 10 is thus executed in direct actuated design and has none pushing force-increasing sequence control so that it is suitable for low switching capacities.

In the longitudinal bore 13 penetrating the housing 14 four chambers formed by annular extensions, of which a first motor chamber 16 with the motor connection B Connection has a return chamber 17 with the return port R is connected to a second motor chamber 18 Motor connection A has connection, while an inlet chamber 19th is connected to the inlet port P. These working chambers 16 to 19 are arranged in the longitudinal bore 13 so that the return chamber 17 between the two engine chambers 16, 18 and the inlet chamber 19 between the second Motor chamber 18 and proportional magnet 15 is arranged.

The longitudinal bore 13 is multiple in the area of the seat valve 11 expanded and receives a valve carrier 21, in the inside of which a valve cone 22 of the seat valve 11 is arranged is. The valve cone slidingly guided in the valve carrier 21 22 has a control edge 23 with subsequent fine control recesses 24, which with associated control openings 25 work together in valve carrier 21. This allows a volume flow proportional to the deflection of the valve plug 22 control that coming from a consumer from the motor connection B led to the return port R and as a drain stream referred to as. For a secure seal of the first engine chamber 16 on the one hand the cone 26 and on the other hand a large overlap on the valve plug stem 27. The valve plug 22 is opposite the pressures in the first engine chamber 16 and pressure-balanced in the return chamber 17, for which he serves to equalize the pressure inside Bores 28, 29 has. The valve cone 22 is from a control spring 31 with its cone 26 on a valve seat 32 pressed, which is arranged inside the valve carrier 21 is and between the first motor chamber 16 and the return chamber 17 lies.

The control spring 31 is supported on an adjusting screw 33, which in turn is arranged in a screw cap 34. The Screw cover 34 is screwed into the face of the valve carrier 21 and limits one that receives the control spring 31 Spring chamber 35 inside the valve carrier 21. The adjusting screw 33 is secured by the lock nut 36.

The valve support 21 has at its front end External thread 37 with which it fits into an internal thread 38 in Housing 14 is screwed. Furthermore, the valve support 21 at a distance from the external thread 37 a collar with external teeth 39, in which a transverse to the longitudinal axis of the valve carrier 21 in the housing 14 screw 41 engages and forms a worm gear 42. By turning the Screw 41 allows valve carrier 21 to move about its longitudinal axis rotate, the pitch of the external thread 37 the axial adjustment determined. Arranged in the longitudinal bore 13 Sealing rings 43 provide a seal for the first motor chamber 16 to both sides. On the one in the valve carrier 21 guided valve plug 22 is on the side of the plug 26 a bolt-like actuator 44 is arranged, that penetrates the return chamber 17 and into the longitudinal bore 13 protrudes coaxially and the adjustment path of a longitudinal slide 45 transfers to the valve plug 22.

The longitudinal bore 13 is in the region of the slide valve 12 executed with the same diameter and takes a piston-like Longitudinal slide 45 on. The longitudinal slide 45 has one first control edge 46 with adjacent fine control notches 47 to a volume flow from the inlet port P to the second To control motor connection A proportionally. With a second Control edge 48 affects the connection from the second Motor chamber 18 to the return chamber 17. The longitudinal slide 45 is opposite the pressures in the inlet chamber 19, the second Motor chamber 18 and the return chamber 17 pressure balanced executed what he did one of his two faces connecting compensating bore 49. The longitudinal slide 45 is coaxial to the valve plug 22 in the longitudinal bore 13 arranged and lies with its left end face on the actuator 44 while he was on his right, opposite lying end face acted upon by the armature axis 51 becomes. The slide valve 12 always controls the Actuator flowing volume flow from the inlet connection P flows to the second motor chamber A and as an inlet flow referred to as.

The operation of the control device 10 is as follows, a 4/2 function with the solenoid-operated valve axis is pictured. In the drawn zero position at not excited proportional solenoid 15, the seat valve 11 is like also the slide valve 12 blocked for the two volume flows; only the second motor connection A is over the second control edge 48 in the slide valve 12 to the return connection R relieved. The proportional magnet 15 is excited and the longitudinal slide 45 and the one resting against it Valve plug 22 deflected to the left, so the connection closed from A to R via the second control edge 48 and the connection for the feed flow from P to A over the first control edge 46 on the longitudinal slide 45 and the connection for the drain flow from B to R via the Control edge 23 on the valve plug 22 opened, the plug 26 stands out from its valve seat 32. With the proportional magnet 15, volume flows can be controlled Size proportional to the electrical input signal on the magnet 15 is.

The discharge flow controlled from B via seat valve 11 to R. can be adjusted in size by a first adjusting device 52 can be set to which the set screw 33 and the control spring 31 count. So you can Change the size of this volume flow by using the Set screw 33 adjusts the bias of the control spring 31 against which the proportional magnet 15 works. The from P via the slide valve 12 to A feed flow can be adjusted with the aid of a second adjusting device 53, why the worm gear 42, the valve carrier 21 and the valve cone 22 count. By turning the worm 42 the valve carrier 21 experiences a rotary movement about its Longitudinal axis that leads to an axial via the external thread 37 Adjustment leads. About the valve plug 22 with his Unlocking member 44 is the longitudinal slide 45 in it Axially adjusted position and thus the coverage of the Control edge 46 changed. The overlap at the control edge 46 of the longitudinal slide 45 can thus be independent of the Coverage of the control edge 23 on the valve cone 22 is adjusted and the associated volume flow can be set. With the The characteristic curves can thus be adjusted 52, 53 set for both volume flows of the 4/2 solenoid valve, see above that the disruptive influence of tolerances of the control edges can be balanced and thus also the tax sequence of the Control edges are easier to handle.

FIG. 2 shows a longitudinal section through a second control device 60, which is different from the first control device 10 mainly differs according to Figure 1 in that the seat valve 61 and the slide valve 62 as piloted Valves are formed, the first adjusting device 63 and the second adjusting device 64 are designed differently and are arranged; otherwise the same components as provided with the same reference numerals in FIG.

In the longitudinal bore 65 penetrating the housing 66 in the same way, the two motor chambers 16, 18 and Return chamber 17 and the inlet chamber 19 arranged, wherein in the area between the first motor chamber 16 and the return chamber 17 in the longitudinal bore 65 and the seat valve 61 associated valve seat 67 is formed.

The housing-fixed valve seat 67 works with one in the Longitudinal bore 67 sliding main control cone 68 together, inside which a valve carrier 69 is concentrically supported, which in turn has a main control cone inside 68 piloting cone 71 takes. To the The outer edge of the main control cone 68 is again the control edge 23 and the fine control recesses 24 arranged with which controls the volume flow referred to as the discharge flow becomes; with its cone 26 it is supported on the housing side Valve seat 67 from. On its opposite face the main control cone 68 limits in the longitudinal bore 65 a pressure chamber 72 which receives a compression spring 73. This compression spring 73 is supported on the one hand on a housing-fixed Cover 74 off while using its other end over a locking ring 75 loads the main control cone 68 and presses on its valve seat 67. Between the fine control recesses 24 and the diameter of the cone 26 an annular space 76 is formed in the longitudinal bore 65, which likewise as the pressure chamber 72 with the same pressure as in the first Engine chamber 16 is loaded because the main control cone 68th is guided with sufficient play in the longitudinal bore 65.

The valve carrier arranged coaxially in the main control cone 68 69 has an external thread 77 with which it fits into an internal thread is screwed into the main control cone 68 so that it can be adjusted axially by rotating it about its longitudinal axis. One formed between valve carrier 69 and main control cone 68 Annulus 78 is axially extending Slot 79 in connection with the pressure chamber 72. The essentially sleeve-shaped valve carrier 69 has in Connection to the external thread 77 an axially formed External hexagon 81, which protrudes into the pressure chamber 72 and penetrates the locking ring 75. For backup of valve carrier 69 against adjustment in main control cone 68 serves this locking ring 75; it faces the front Teeth and engages in a toothing 82 of the main control cone 68. The inner contour of the locking ring 75 engages form-fitting around the external hexagon 81 of the valve carrier 69, and also has breakthroughs 83 that the oil exchange between allow the pressure space 72 and the annular space 78.

The valve carrier 69 is the one used for pilot control Pilot cone 71 arranged by a spring 84 its seat in the valve carrier 69 is pressed. With this Pilot cone 71 is the seat diameter and the shaft diameter the same size, and there is an equalization hole inside provided so that the pilot cone 71 as pressure balanced valve can work. The spring 84 receiving space is through a floor 85 which is in the valve support 69 is closely arranged, separated from the pressure chamber 72. in the closed state of the pilot cone 71 seals it due to its seat and its long shaft, which only has a small game, the annulus 78 well opposite the return chamber 17. The valve carrier 69 forms here a part of the second adjustment device 64.

In the area of the inlet chamber 19 and the second motor chamber 18 is a main control slide 86 in the longitudinal bore 65 performed, which is a part of the pilot operated slide valve 62nd forms. It has the first control edge on its outer circumference 46 and the fine control notches 47, which the from P after A controlled volume flow, the inlet flow. Further the main control slide 86 has the second control edge 48 to control the connection from A to R. By doing Main spool 86 is coaxially a pilot spool 87 slidably guided by the main spool 86 after Kind of a hydraulic sequencer works together. To for this purpose the pilot spool 87 has a control edge 88 with which he has a cross bore 89 in the main spool 86 controls. In this way, the spool can 87 influence a control oil flow, which of the Inlet chamber 19 branches off via the transverse bore 89 and Control edge 88 in a longitudinal bore 91 of the pilot spool 87 arrives, from there via a throttle point 92 in one Unlocking piston 93 flows and continues through openings in a screw cap 94 reaches the return chamber 17. The screw cover 94 fastened in the main control slide 86 protrudes with a plunger 95 into the return chamber 17 and lies with its end having a slot 96 on the valve carrier 69 in the seat valve. Inside the plunger is 95 coaxially guided an unlock pin 97, the one hand on the unlocking piston 93 and on the other hand on the pilot cone 71 is present. Through the plunger 95 and the unlocking pin 97 is between the slide valve 62 and the seat valve 61 mechanical operative connection established. The unlocking piston 93 has a larger diameter than the pilot spool 87 and is coaxial to the latter in one Recess of the main control slide 86 slidably longitudinally guided. The recess is through the screw cap 94 shut off, which the unlocking piston 93 additionally as a stop serves. The unlocking piston 93 limits in this way in the recess a space 98 in which the longitudinal bore 91 of the pilot valve 87 opens.

The accumulated by the throttle point 92 in the unlocking piston 93 Pressure also acts through the hollow spool 87 in a pressure chamber 99 which in the longitudinal bore 65 of the right end of the main spool 68 limited becomes. An adjusting screw lies in this pressure chamber 99 101, which with its external thread 102 in a corresponding Internal thread of the longitudinal bore 65 is screwed. This Adjusting screw 101 has the external toothing on its outer circumference 39, in which the screw 41 engages and thus forms the worm gear 42. A longitudinal section through this worm drive 42 is shown in Figure 3, the one Partial section according to III-III in Figure 2 shows. At the inside this adjusting screw 101, the control spring 103 is now arranged, the one hand on a free end of the adjusting screw 101 and on the other hand on a bolt-shaped End of the pilot spool 87 supports that in the adjusting screw 101 protrudes. In addition, this is bolt-shaped End of the armature axis 51 of the proportional magnet 15 on. The adjusting screw 101 with the worm gear 42 forms here the first adjustment device 63, which in this way between the pilot operated slide valve 62 and the Proportional magnets 15 arranged in the longitudinal bore 65 is.

The operation of the second control device 60, which here is designed as a pilot operated 4/2 solenoid valve, is how follows explained, the slide axis being controlled by the pilot Construction can be used for larger performances.

It is assumed that the second control device 60 part of a double acting control valve is, as in the or part of the application mentioned in the introduction of a similar valve. In this case it is at zero the second control device 60 at the inlet connection P always the control pressure of a pressure compensator or the Standby pressure of a control pump on. The control edge 88 of the Pilot spool 87 blocks a control oil flow, so that the pressure chamber 99 over the hollow spool 87 and the throttle point 92 in the unlocking piston 93 Return chamber 17 is relieved. On the other hand, there is in the first motor chamber 16 of the line B coming up Load pressure, which affects the radial play of the main control cone 68 also form in the annular space 76 and in the pressure space 72 can. As a result of the larger effective area in the pressure chamber The main control cone 68 becomes 72 on its valve seat 67 pressed, the compression spring 73 in the same Direction works. The pilot operated seat valve 61 ensures this for a secure seal of the motor connection B.

If the proportional magnet 15 is now excited, its armature axis exercises 51 exerts a force on the pilot spool 87, whereby the prestressed control spring 103 of the magnetic force keeps the balance. The pilot spool 87 is thereby deflected to the left, its control edge 88 the transverse bore 89 controls, so that a control oil flow from the Inlet connection P via the pilot valve 87 and the throttle point 92 in the unlocking piston 93 to the return port R can build up. The stagnation of the control oil flow through the Throttle point 92 increases depending on the opening of the transverse bore 89 through the spool 87 the pressure upstream of the throttle point 92 and thus in the room 98. This pent up Pressure passes through the longitudinal bore 91 in the pilot valve 87 also in the pressure chamber 99, where he the main slide 86 acted on its right face. The pressure in room 98 acts on the unlocking piston 93 and presses the unlocking pin 97 the pilot cone 71 in an open position, when the force on the unlocking piston 93 the force of the spring 84, which acts on the pilot cone 71, exceeds. If the pilot cone 71 opens, the pressure chamber becomes 72 through the openings 83, the slot 79 and the Annulus 78 to the return chamber 17 is relieved. With that the sinks Pressure in the pressure chamber 72 and the main control cone 68 can in the manner of an unlockable check valve by the Tappet 95 on the main control slide 86 can be moved to the left.

The pressure in the pressure chamber 99 is from the throttle point 92 in the unlocking piston 93 and on the other hand from the opening cross section determined on the transverse bore 89, and pushes first the unlocking piston 93 to the left until it stops on screw cap 94. After fitting the unlocking piston 93 this pressure will also change in the pressure chamber 99 fully build up and cover the entire face of the main spool Act on 86. Here is the power that thereby acting on the main spool 86, larger than that restoring force of the compression spring 73, the moves Main control spool 86 with the main control cone 68 as one one-piece, related control element with all its Split left. This is done by stepping up or stepping on the transverse bore 89 the entire valve axis to the left or shifted to the right, d. H. the main control slide 86 with the main control cone 68 resting on its tappet 95 follows the movements of the pilot spool 87 in the manner of a hydraulic sequence control. Now, on the one hand the sink current from B to R via the control edge 23 with the Fine control phases 24 on the main control cone 68 are affected while the volume flow from P to A to the servomotor from the control edges 46 with the fine control notches 47 in it Size is affected. The deflection of the spool 87 is thereby by the force of the proportional magnet 15 and the force of the prestressed control spring 103 is determined.

Since the control spring 103 is supported on the adjusting screw 101, can by turning the screw 41 and the associated axial adjustment of the adjusting screw 101 the bias the control spring 103 can be changed so that the location the flow characteristic flow rate Q as a function of Current I in the magnet 60 is adjustable. This will also the position of the control edge 46 changed, so that a total of of the first adjusting device 63, the inlet flow can be adjusted is.

After setting the feed flow via the pilot operated Slider valve 62 can also drain the current through the pilot operated seat valve 61 with the aid of the second adjusting device 64 can be set. For this purpose the valve carrier 69 of the pilot cone 71 through its external thread 77 axially adjustable relative to the main control cone 68. The valve carrier 69 is rotated with a special tool, the axially inserted for adjustment in the pressure chamber 72 and reaches over the external hex 81. On the valve carrier 69, the plunger 95 is supported on the screw cap 94. The rotation of the valve support 69 thus has a change in distance of the two fine control recesses 24 on the main control cone 68 and 47 on the main control slide 86 relative to each other result. In this way the overlaps are on two control edges 23 and 46 adjustable for both volume flows, so that the drain flow can be adjusted from B to R. is.

FIG. 4 shows a longitudinal section through a third control device 110, which is different from the second control device 60 according to Figure 2 differs as follows, wherein for same components same reference numerals are used.

The third control device 110 uses a different seat valve 111 in connection with another second adjustment device 112, the pilot operated slide valve 62 remains unchanged with the first adjusting device 63. In the pilot operated poppet valve 111 is the pilot pilot cone 113 slidingly arranged directly in the main control cone 114, while the main control cone 114 in turn in the Valve carrier 115 is slidably disposed. The valve carrier 115 is in an expanded section of the longitudinal bore 65 rotatably and axially movable, for which he with a External thread 116 in a corresponding internal thread Longitudinal bore 65 is screwed. Furthermore, is on the valve support 115 a similar worm drive 117 is formed, as it already has the adjusting screw 101. Comparable Way as in the first control device 10 according to Figure 1, the first motor chamber 16 by seals 118 secured on both sides. The valve carrier 115 has one at its end facing the return chamber 17 Valve seat 119 for the associated main control cone 114 while its other end is closed by a lid 120 which is the pressure chamber accommodating the compression spring 73 72 cordoned off. The pilot cone 113 is the same Way as carried out according to Figure 2 in a pressure-balanced manner and serves in a corresponding manner for pilot control of the Main control cone 114.

In the third control device 110, the inlet flow from P to A in the same way via the first adjustment device 63 set while setting the drain current from B to R the second adjustment device 112 is used. With the help of the worm gear 117, the valve carrier can be 115 adjust axially in the longitudinal bore 65, whereby its effective control edge in the control opening 121 relative to the control edge fixed to the housing in the slide valve in its position is changed. This can be done in a corresponding manner in the second control device 60 according to FIG. 2 also the Drain current from B to R can be adjusted or set.

FIG. 5 shows a longitudinal section through a fourth control device 130, which is different from the third control device 110 as shown in Figure 4, where for same components same reference numerals are used. The fourth control device 130 uses a different seat valve 131 and a little modified slide valve 132, the control members themselves in the manner of a hydraulic Sequence control work together so that the Main control cone 133 in the seat valve no longer mechanically from Main spool 134 is operated, but hydraulically.

The structure of the housing 66 with the four working chambers 16 to 19, the basic structure of the main control spool 134 with its control edge 46 and the fine control notches 47, the Pilot valve 87 and the adjusting screw 101 with the first adjustment device 63 are essentially the same as in the third control device 110 according to FIG. 4. In the Main spool 134 is instead of the screw cap 94 now a plunger 135 with a plate-shaped extension 136 held. The plate-shaped projection 136 is thereby by a return spring 140 which is supported fixed to the housing loaded and thus against the left face of the main spool 134 pressed, the lug 136 on its Outer circumference is centered in the main control slide 134. The throttle point 92 provided for the control oil flow is now arranged in the plate-shaped neck 92, since a separate Unlocking piston 93 in the main control slide 134 is omitted.

The pilot operated seat valve 131 is like the third Control device 110 according to Figure 4 inside a valve carrier 137 arranged, which in turn in the remote Section of the longitudinal bore 65 is mounted. The valve carrier 137 has the external thread 116 on its outer surface with which it fits into a suitable internal thread of the longitudinal bore 65 is screwed in and is therefore axially adjustable. On a worm gear 117, the valve carrier 137 dispenses with the position of a lock nut 138 is secured.

The main control cone 133 arranged in the valve carrier 137 is here designed as a differential area valve, in which a ring surface formed by seat edge and valve stem 139 of the one prevailing in the first motor chamber 16 Pressure is applied in the opening direction. The main tax cone 133 compression spring 73 loading in the closing direction lies in the pressure chamber 72, which is arranged in the valve stem Throttle 141 in connection with the first motor chamber 16 stands. The main control cone 133 has as before Main control edge 23 and the fine control grooves 24 for control of the drain stream, whereby it is the actual one in the drain stream Cones are connected downstream. The pilot cone arranged in the main control cone 133 is here designed as a ball 142, which sits between two valve seats is arranged in the main control cone 133 and with a tapered extension 143 of the plunger 135 in operative connection stands as it is required for the hydraulic sequence control is.

The valve carrier 137 is rotatable about its longitudinal axis and undergoes an axial adjustment as a result of the external thread 116, so that it is part of the second adjustment device 144 represents.

The operation of the fourth control device 130 is the same to that extent that of the third control device 110 Figure 4, as the main spool 134 with the spool 87 works in the manner of a hydraulic follow-up control, to control the feed flow from P to A. The influenced by the throttle point 92 in the control oil flow Back pressure, which is also in the control chamber 99 on the right Front of the main control spool 134 acts, shifts now this - in contrast to the third control device 110 - essentially against the return spring 140, the is supported on the valve carrier 137 fixed to the housing. Furthermore serves the coupled with the main spool 134 Tappet 135 for additional hydraulic sequence control of the seat valve 131. For this purpose, on

Main control cone 133 the opening force by the pressure of the Load in the first motor chamber 16 on the ring surface 139 exerted while the closing force on the main control cone 133 from the pressure in the pressure chamber 72 to the whole effective area of the main control cone 133 becomes. Ball 142 in main control cone 133 is part of its pilot valve. Raise the plunger 135 over his Extension 143 the ball 142 from its seat, so that opens Pilot valve and relieves pressure chamber 72 to the return chamber 17. The one hand via the throttle 141 in the pressure chamber 72 inflowing oil and the other through the ball valve flowing out of the pressure chamber 72 to the return chamber 17 Oil determine the pressure in the pressure chamber 72 that on the left Front of the main control cone 133 acts and thus its direction of movement. The main control cone 133 is thus hydraulically adjusted against the force of the spring 73, wherein it follows the position of the plunger 135 with its position, so that the seat valve 131 also has a sequence control here, which derive their energy from the load pressure of the first motor connection 16 relates. The fourth controller 130 is therefore suitable for great performances.

While the feed flow from P to A continues as before via the first Adjustment device 63 is adjustable, the drain current from B to R via the second adjustment device Set 144. A rotational movement of the valve carrier 137 is in an axial adjustment via the external thread 116 converted, whereby the position of the control edge 23 relative to Position of the main control spool 134 is changed so that the drain current can also be adjusted.

FIG. 6 shows a longitudinal section through a fifth control device 150, which is different from the second control device 60 according to Figure 2 differs as follows, wherein for same components same reference numerals are used.

The fifth controller 150 uses another one Main control slide 151, in which the plunger 95 with the actual Main control slide is made in one piece. In the inside of the main control slide 151 has one Adjustment screw 101 open blind hole 152, in which of the pilot spool 87 and the unlocking piston 93 are slid in a row. The blind hole 152 is of the same diameter throughout, so that the unlocking piston 93 and the spool 87 have the same outside diameter. The slide valve 62 in the fifth control device 150 therefore comes along fewer components and is easier and cheaper produce. The adjustment devices 63 and 64 can remain unchanged. Otherwise, the Operation of the fifth controller 115 like that the second control device 60.

Of course, the embodiments shown are Changes possible without any of the features of the invention, as defined in claim 1. It is assumed that even with a hydraulic Sequence control a mechanical operative connection between pilot and controlled valve member.

Claims (27)

1. Electrohydraulic control device for controlling the volume flows for a hydraulic servomotor as a function of electrical input signals at the proportional magnet, with valve means which perform a 4/2-way function and which have a releasable seat valve (11; 61; 111; 131) for controlling the volume flow flowing out from the servomotor and a slide valve (12; 62; 132) for controlling the inflowing volume flow, the control members of the seat valve and slide valve being arranged one behind the other in a longitudinal bore of a housing, so that the slide valve (12; 62; 132) is located between the seat valve (11; 61; 111; 131) and the proportional magnet (15), and in which, in the housing (14), a first motor chamber (16) and a return chamber (17) are assigned to the outflow, whilst a second motor chamber (18) and an inflow chamber (19) are assigned to the inflow, the return chamber (17) being located between the two motor chambers (16, 18) and the inflow chamber (19) being located outside the two motor chambers (16, 18), and with a first adjusting arrangement (33; 42; 101), in which one of the volume flows can be set by a change in the prestress of a regulating spring (31, 103), characterized in that the seat valve (11; 61; 111; 131) and the slide valve (12, 62; 132) have control members (22, 45; 68, 71; 86, 87; 114, 113; 133, 142, 134; 151) which are separate from one another and are operatively connected to one another mechanically, and in that a second adjusting arrangement (53; 64; 112; 144) is provided, by means of which the other volume flow can be set.
2. Electrohydraulic control device according to Claim 1, characterized in that, by means of the first adjusting arrangement (52; 63), the position of the throughflow characteristic of volume flow as a function of the electrical input signal at the proportional magnet (15) can be set at one of the control edges (23, 46), whilst, by means of the second adjusting arrangement (53; 64; 112; 144), the position of the effective control edges (23, 46) on the seat valve (11; 61; 111; 131) and on the slide valve (12; 62; 132) relative to one another can be adjusted.
3. Electrohydraulic control device according to Claim 1 or 2, characterized in that the seat valve (11) and the slide valve (12) which provide the 4/2-way function are designed as directly controlled valves, and the seat valve (11) has a sleeve-shaped valve carrier (21) which receives inside it a valve cone (22) and on which the two adjusting arrangements (52, 53) are arranged.
4. Electrohydraulic control device according to Claim 3, characterized in that the first adjusting arrangement (52) has a setscrew (33) which is arranged coaxially in the valve carrier (21) and on which the regulating spring (31) acting on the valve cone (22) is supported.
5. Electrohydraulic control device according to Claim 3 or 4, characterized in that the second adjusting arrangement (53) has a worm drive (42), in which an external toothing (39) on the valve carrier (21) has engaging into it a worm (41) mounted transversely thereto in the housing (14), and in that the valve carrier (21) is screwed via a thread (37) into the longitudinal bore (13).
6. Electrohydraulic control device according to one of Claims 3 to 5, characterized in that the valve carrier (21) has, at its end located opposite the first adjusting arrangement (52), a valve seat (32) which is assigned to the valve cone (22).
7. Electrohydraulic control device according to one of Claims 3 to 6, characterized in that the valve cone (22) is coupled mechanically to a longitudinal slide (45) of the slide valve (12) via an actuating member (44) fastened, in particular, to the valve cone.
8. Electrohydraulic control device according to one of Claims 3 to 7, characterized in that the valve cone (22) is designed to be pressure-compensated with respect to the pressures in the first motor chamber (16) and in the return chamber (17), and the longitudinal slide (45) is pressure-compensated with respect to the pressures in the second motor chamber (18) and in the inflow chamber (19).
9. Electrohydraulic control device according to one or more of Claims 3 to 8, characterized in that the valve cone (22) and the longitudinal slide (45) each have a control edge (23, 46) inserted into the outflow (B-R) and the inflow (P-A) respectively and with fine control recesses (24, 47).
10. Electrohydraulic control device according to Claim 1 or 2, characterized in that the seat valve (61; 111; 131) and the slide valve (62; 132) which form the 4/2-way function are in each case designed as pilot-controlled valves which are operatively connected to one another.
11. Electrohydraulic control device according to Claim 10, characterized in that the first adjusting arrangement (63) is arranged between the slide valve (62, 132) and the proportional magnet (15) in the longitudinal bore (65), whilst the second adjusting arrangement (64; 112; 144) is assigned to the seat valve (61; 111; 131).
12. Electrohydraulic control device according to Claim 11, characterized in that the first adjusting arrangement (63) has a setting screw (101) which is screwed with its external thread (102) into an internal thread of the longitudinal bore (65), so that said setting screw is arranged axially adjustably between a main control slide (86; 134; 151) of the slide valve (62, 132) and the proportional magnet (15), in that the setting screw (101) has an external toothing (39), into which a worm (41) mounted transversely thereto in the housing (66) engages in the manner of a worm drive (42), and in that the regulating spring (103) is supported between the setting screw (101) and a pilot-control slide (87) which co-operates with the main control slide (86; 134; 151) in the manner of a hydraulic follow-up control.
13. Electrohydraulic control device according to one of Claims 10 to 12, characterized in that the second adjusting arrangement (64) has a sleeve-shaped valve carrier (69) which receives inside it a pilot-control cone (71) which pilot-controls a main control cone (68) and which is arranged axially adjustably in the main control cone and is operatively connected to a tappet (95) of the main control slide (86) in the slide valve (62).
14. Electrohydraulic control device according to Claim 13, characterized in that the valve carrier (69) is screwed in the axial direction with an external thread (77) into an internal thread of the hollow main control cone (68) and has an outer key surface (61), by means of which said valve carrier is secured fixedly in terms of rotation in the main control cone (68) via an axially installable retaining ring (75).
15. Electrohydraulic control device according to Claim 14, characterized in that a compression spring (73) loading the main control cone (68) is supported on the main control cone (68) via the retaining ring (75).
16. Electrohydraulic control device according to one of Claims 10 to 12, characterized in that the second adjusting arrangement (112; 144) has a sleeve-shaped valve carrier (115; 137) which receives the valve seat (119) and which is arranged axially adjustably in a stepped part of the longitudinal bore (65) and which receives inside it the main control cone (114; 133) together with the pilot-control cone (113; 142) arranged in the latter.
17. Electrohydraulic control device according to Claim 16, characterized in that the valve carrier (115) is screwed with an external thread (116) into an internal thread of the longitudinal bore (65) and has an external toothing, into which a worm mounted transversely thereto in the housing (66) engages in the manner of a worn drive (117), and in that the main control cone (114) is operatively connected to a tappet (95) of the main control slide (86).
18. Electrohydraulic control device according to Claim 16 or 17, characterized in that the valve carrier (115; 137) receives the compression spring (73) loading the main control cone (114; 133), in a pressure space (72) which is closed relatively outside, in particular, by means of a cover (120) arranged in the valve carrier.
19. Electrohydraulic control device according to one of Claims 13 to 18, characterized in that the pilot-control cone (71; 113) pilot-controlling the main control cone (68; 114) is designed to be pressure-compensated on all sides, and in that said pilot-control cone is inserted into the hydraulic connection from a pressure space (72) assigned to the main control cone (68, 114) to the return chamber (17) and is operatively connected to a release pin (97) which is mounted slideably in a tappet (95) of the main control slide (86).
20. Electrohydraulic control device according to one of Claims 13 to 19, characterized in that the main control slide (86) has arranged in it coaxially to the pilot-control slide (87) a hydraulically actuable release piston (93), the associated throttle point (92) of which is inserted into a control-oil flow serving for the follow-up control and carried by the inflow chamber (18) to the return chamber (17), said release piston (93) being operatively connected to the release pin (97).
21. Electrohydraulic control device according to one of Claims 13 to 20, characterized in that the main control slide (86; 134; 151) and the main control cone (68; 114; 133) each have a control edge (23, 46) inserted into the inflow and the outflow respectively and with fine control recesses (24, 47).
22. Electrohydraulic control device according to one of Claims 10 to 12, characterized in that the second adjusting arrangement (144) has a sleeve-shaped valve carrier (137) without external toothing, which is screwed axially adjustably in a stepped part of the longitudinal bore (65) by means of an external thread (116) and which receives inside it the main control cone (133) and the pilot-control member (142) arranged in the latter, the main control cone (133) delimiting in the valve carrier (137) a pressure space (72) receiving the compression spring (73), and in that the valve carrier (137) is capable of being locked in its rotary position on the housing (66) by means of a retaining element (138).
23. Electrohydraulic control device according to Claim 22, characterized in that the main control cone (133) is designed as a differential-area valve and the pilot-control cone as a spherical closing member (42), which, together with the tappet (135) operatively connected to the main control slide (134), form a follow-up control, and in that the main control slide (134) is supported at its non-pressure-loaded end fixedly relatively to the housing via a restoring spring (140).
24. Electrohydraulic control device according to Claim 23, characterized in that the tappet (135) is guided in the main control slide (134) via a dish-shaped extension (136) and is held in bearing contact on the latter by the restoring spring (140), and in that a throttle point (92) is arranged, in particular, in the extension (136).
25. Electrohydraulic control device according to one of Claims 10 to 12 and 16 to 21, characterized in that the valve carrier (21; 115; 137) passes through the first motor chamber (16) and is sealed off on the outside in the longitudinal bore (13, 65) on the first motor chamber (16) on both sides by means of sealing rings (43; 118).
26. Electrohydraulic control device according to one of Claims 13 to 15, characterized in that the main control cone (68) and the main control slide (86) are slideably guided directly in the longitudinal bore (65), in which a valve seat (67) for the main control cone (68) is arranged between the first motor chamber (16) and the return chamber (17).
27. Electrohydraulic control device according to one or more of Claims 10 to 26, characterized in that the main control slide (151) is designed in one piece with the tappet (95), and in that the pilot-control slide (87) and blocking piston (93), which are guided slideably in said main control slide and are arranged one behind the other, have the same outside diameter and are guided in the same bore (152).

Images