DE19728092A1 - Hydraulic control device for defined control of e.g. engine - Google Patents

Abstract

With closed control nozzles (13) on the basis of the diaphragm in the valve bodies (2-5), the pressure out of the connecting conduits (A, B, P) builds up in the corresponding control chambers (15). In a preferred form of each valve piston (7), there is a difference between the piston surface and the seat surface of approximately 10 per cent. The pilot valve (11) is provided with four path-proportionally opening control nozzles (13) and an overflow opening to the outflow conduit. In the "O" position of the control component all four control nozzles are closed and corresponding to the displacement direction and dependent upon the displacement path of the control component, the two control nozzles provided for the corresponding displacement direction and together with the connected control conduits are opened and closed with synchronous cross-section, with the pressure in the control chambers altering dependent upon the displacement path.

Description

The invention relates to a hydraulic control device for the defined Control of a motor, for example, using 2-way on construction valves.

Such devices are in a wide variety of prior art Embodiments described above. Here, especially with large Flow rates in connection with 2-way cartridge valves Pilot controls used. These described in the prior art Pilot controls on the one hand consume tax oil on the one hand and are on the other hand only in connection with a very high, in addition to the manufacturing and Installation effort always increasing the space required technical Additional effort (for example in connection with lowering, brake valves and / or Load holding valves) capable of defining four valves simultaneously to control that, for example, a defined, exactly delayed lowering a load, or a load holding function by means of in the prior art usual control of a differential cylinder is possible. Furthermore with every 2-way cartridge valve there is a risk that if the the valve piston loading spring the valve is opened.

The invention is therefore based on the object of a hydraulic To develop control device which does not have the aforementioned disadvantages has, with minimal manufacturing and assembly costs and without additional space requirement and even in connection with any commercially available Connection plate (with standardized hole pattern) even the defined path and speed-controlled control of a differential cylinder enables simultaneous realization of a load holding function and thereby can also ensure a safety function, so that even with one Breakage of the valve spring of the 2-way on which loads the piston crown construction valve the valve always remains closed.

According to the invention, this object is achieved in that the defined hydraulic control of an engine for example in its path time behave using four 2-way cartridge valves, in Piston plate of each spring-loaded valve piston in the direction of it Longitudinal axis panels with a diameter of approximately 0.05 mm to 1 mm are arranged, arranged by means of this in the piston crowns Apertures according to the invention with closed control nozzles Pressure equalization in the two connected by the respective orifice Valve chambers is guaranteed, so that in the respectively assigned Control chamber which builds up pressure from connection lines A, B and P.

It is characteristic that each valve piston preferably has a difference between piston surface and seat surface of approx. 10% (compared to that in stand the usual area difference of approx. 7%).

In connection with those arranged according to the invention in the piston crowns Apertures and the pressure compensation thus achieved according to the invention achieved that each valve piston in the operating state even when broken Valve spring is always pressed on the seat assigned to it in the valve body.  

It is also important that the pilot valve with four opening proportionally Provide control nozzles and an overflow opening to the drain line according to T. is, with all four control nozzles in the "0" position of the control element are closed and according to the direction of displacement and in The two depending on the respective displacement of the control element the corresponding control direction associated control nozzles and the control lines connected to them simultaneously and continuously, from Displacement varies depending on the pressure in the control chambers, can be opened or closed cross-section synchronously.

Due to the use of a pilot valve with these features essential to the invention are in conjunction with the previously described valve piston according to the invention with minimal manufacturing and installation effort as well as a defined and without additional space requirement exact control of the motor is achieved, so that, for example, during use a piston engine the piston is clamped in every phase of its movement and can be moved in a defined manner even under load. Thus at minimal effort by the solution according to the invention a lowering, braking and load holding function are guaranteed.

It is also essential to the invention that in the connecting line adjacent valve body for connecting the respective consumer A or B, a check valve immediately after the valve acted upon by P can be arranged.

This check valve can prevent, for example, pressure intensifications when driving a differential cylinder when the load pressure in one of the Consumer connections A or B is larger than at connection P, the Backflow of the hydraulic fluid into the connecting line P and avoids thus the operation of the differential cylinder in the differential rapid traverse. Of course, with the arrangement according to the invention, by not using the vg. Check valves, the effect of a Differential rapid traverse switching achieved when driving a differential cylinder become.  

Another feature of the invention is that as a pilot valve in one assigned pilot valve body with four control nozzles and overflow opening for Drain pipe according to T a spring-loaded with conical control surfaces and Thrust pistons provided through holes arranged as a control element is.

This special embodiment of the pilot valve according to the invention can can be controlled, for example, by means of two electric thrust magnets.

There is a pilot valve chamber with a in the pilot valve Overflow opening and the drain line connected to this to T and four, defined by the geometry of the control element, Control nozzles arranged at a distance from one another, via control lines are connected to the control chamber of the respectively assigned valve body. The control element is in the cylindrical valve chamber of the pilot valve Form of a driven for example by a solenoid Thrust piston, arranged. This control in the form of a Thrust piston has a preferably centrally arranged bore, for example a through hole.

Conical control surfaces are arranged on the circumference of the thrust piston through holes with this through hole of the control element are connected.

According to the invention, all four are always in the rest position of the control element Control nozzles closed. By the horizontal shift of the Shear pistons are in accordance with the direction of displacement and in Depending on the respective displacement path, the two of the at the same time corresponding control direction associated control nozzles Open continuously, synchronously depending on the displacement path or locked.

It is also essential that as a pilot valve in an assigned Pilot valve body with four control nozzles and overflow opening to the drain line after T a cylindrical one, with internal bores and with two on top of each other each over less than half the circumference and against each other by 180 °  staggered eccentric grooves provided, rotary piston as Control is arranged. The inner holes connect the Control surfaces of the eccentric grooves with the overflow opening in the Pilot valve body. The cylindrical in this embodiment, with two Eccentric grooved control is in the associated Base body of the pilot valve rotatable about its longitudinal axis and can thus can be driven, for example, by means of a servo motor.

According to the invention is also that as a pilot valve in an associated Pilot valve body with four control nozzles and an overflow opening for Drain pipe according to T one conical, with inner bores and two over each other over less than half the circumference and against each other eccentric grooves provided offset by 180 °, Rotary piston is arranged as a control element. Connect the inner holes again the control surfaces of the eccentric grooves with the Overflow opening in the pilot valve body. Even the conical control is rotatable about its longitudinal axis and can, for example, turn are driven by a servo motor. Furthermore, this has conical embodiment the advantage that just in the "0" position of the Control element, all nozzle openings are hermetically sealed, so that no leakage losses can occur.

In this context, it is characteristic that, for example, during use of hermetically closing pilot valves, in the valve block between the Valve body and the sliding surfaces of the valve piston, seals arranged can be. This also means that the "0" position of the Control element otherwise inevitable leakage losses and this avoids pressure equalization.

According to the invention is further that as a pilot valve in an associated Pilot valve body with control nozzles and overflow openings to the drain line after T two conical thrust pistons, each with one in the piston crown as Blind hole arranged through which one in the cone area  arranged radial through hole is guided as controls are arranged.

The controls are used to "open" or "close" translationally in the direction of their axis of rotation in the associated Pilot valve chamber, for example, via thrust magnets and / or a Lever system moved. The change between the control element and pilot valve chamber resulting control gaps proportional to the path, so that with this arrangement according to the invention, the control pressure for Activation of the check valves according to the invention varies path-proportionally can be. Since this seat valve also closes hermetically, associated valve block between the valve body and the sliding surfaces of the Valve piston, seals arranged. Thus also by means of this Arrangement according to the invention, the leakage losses and the thereby taking place Pressure equalization avoided.

The solution according to the invention will now be described below with reference to a few Exemplary embodiments explained in connection with five figures.

Show:

Fig. 1 is an illustration of the hydraulic control device according to the invention as a schematic principle sketch for illustration of the control element in the form of a spring-loaded thrust piston with greatly enlarged gap widths shown,

Fig. 2 representation of the hydraulic control device according to the invention with thrust piston control;

Fig. 3 representation of the hydraulic control device according to the invention with rotary piston control (cylindrical);

Fig. 4 representation of the hydraulic control device according to the invention with rotary piston control (conical);

Fig. 5 representation of the hydraulic control device according to the invention with reciprocating piston control (conical).

As shown in Fig. 1, the four 2-way valve body 2 , 3 , 4 , 5 and the associated wiring harnesses are arranged in a valve block 1 (for example with a connection hole pattern according to DIN 24340 Form A 10). In the valve bodies 2 , 3 , 4 , 5 there are valve pistons 7 loaded with valve springs 6 . The piston heads of the spring-loaded valve pistons 7 of each 2-way cartridge valve are provided with orifices in the direction of their longitudinal axis. The diameter of this circular aperture is 0.5 mm in the present case.

This in the piston crown of each 2-way cartridge valve according to the invention arranged orifice ensures pressure equalization when closed Control nozzle in the two valve chambers connected by the orifice.

In addition, a check valve 9 is arranged in the connecting line of the two valve bodies 2 and 3 for connecting the consumer A, immediately after the second valve body 3 acted upon by P. There is also the connecting line of the two valve bodies 4 and 5 for connecting the consumer B, immediately after the third valve body 4 acted upon by P, a further check valve 9 . These two check valves prevent pressure backflow of the hydraulic fluid into the connecting line P when pressure ratios, for example as in the exemplary embodiment shown in FIG. 1 when driving a differential cylinder, when the load pressure in one of the consumer ports A or B becomes greater than at port P.

A pilot valve 11 is screwed onto the valve block 1 . In this pilot valve 11 there is a pilot valve chamber 12 with an overflow opening and the discharge line 20 connected to it to T as well as four control nozzles 13 , which are defined by the geometry of the control element 16 and are arranged at a distance from one another and which are connected via control lines 14 to the control chamber 15 of the respectively assigned one Valve body 2 , 3 , 4 or 5 are connected.

The control element 16 is arranged in the form of a thrust piston in the cylindrical valve chamber 12 . This control element 16 has a centrally arranged bore 17 .

Conical control surfaces 18 are arranged on the circumference of the control element 16 and are connected to the bore 17 of the control element 16 via passage bores 19 .

In the rest position of the control element 16 , all four control nozzles 13 are closed. Since each of the valve pistons 7 according to the invention has a difference of approximately 10% between its piston surface and its seat surface in the present case, the valve pistons 7 are adjusted to their respective positions due to the pressure compensation via the orifices 8 arranged in the valve pistons 7 in the two valve chambers connected according to the invention Seat surfaces in the assigned 2-way valve bodies 2 , 3 , 4 , 5 pressed. At the same time, this effect is further enhanced by the valve springs 6 acting on the valve piston 7 .

All connections A, B, P and T are locked in the rest position of the control element 16 . The piston of the engine 10 is thus clamped in the working cylinder.

If the piston of the control element 16 is now moved to the right, the control nozzles assigned to the 2nd valve body 3 and the 4th valve body 5 are opened continuously via the control surfaces 18 depending on the displacement path. The throttle gap that arises increases proportionally with the displacement of the control element 16 . At the same time, the pressure P present falls in the control line 14 and the control chamber 15 of the second valve body 3 in proportion to the increase in the throttle gap. As a result, the valve piston 7 lifts off its valve seat in the second valve body 3 and allows a regulated volume flow from the connecting line P to flow through the assigned check valve 9 to the consumer connection A.

At the same time, a pressure builds up in the control chamber of the fourth valve body 5 due to the diaphragm 8 in the valve piston 7 , which pressure results from the thrust force of the piston and the truck train or the truck pressure. This pressure in the control chamber of the fourth valve body 5 is also present in the associated control line 14 and also in the associated control nozzle 13 .

The check valve 9 arranged between the third valve body 4 and the fourth valve body 5 now prevents in the present design according to the invention when a differential cylinder is used, the “load pressure” at the consumer port B becoming greater than at the port P, as shown in FIG. 1, an overflow of the hydraulic fluid according to P.

If these check valves 9 were not installed, the arrangement according to the invention then modified would result in a differential rapid traverse circuit.

Since the throttle gap on the control nozzle 13 of the 2nd valve body 3 now also opens synchronously and proportionally with the throttle gap on the control nozzle 13 of the 4th valve body 5 on the pilot valve, the pressure in the control chamber 15 of the 4th valve body 5 also builds up at the same time from.

The valve piston 7 arranged there lifts off its seat and allows a regulated volume flow to flow from B to T. As a result, the piston rod of the motor 10 moves precisely regulated and at the same time "clamped" to the right, so that no advance caused by this extreme load is possible even under extreme load.

From the exactly defined movement characteristics of the Control of the motor according to the invention also results in its lowering, Braking as well as its load holding function, which in contrast to the realization of these functions with the others customary for this in the prior art Designs avoids the use of additional assemblies.

In FIG. 2, in connection with the two-dimensional schematic representation according to Fig. 1, type described now is the solution of the invention shown in somewhat modified three-dimensionally. In addition to the control nozzles 13 already described, an overflow opening to the drain line 20 is shown in the valve block of the pilot valve 11 . The translational displacement of the control element 16 can take place, for example, by means of two thrust magnets.

In this particular embodiment, the invention hydraulic control device a pump as a motor for generating a Torque driven. In the case selected here, the Installation of check valves in the valve block of the invention hydraulic control device dispensed with, since it was assumed that the Pressure in consumer connections A or B is always lower than at the connection P is.

However, in one of the consumer lines, for example Torque initiation on the motor, the system pressure P in A or B is noticeable exceeded, it lifts depending on the existing on the valve piston Ring surface and the valve spring used in each case (in the embodiment at about 115%) the assigned valve piston from its seat and leaves the system pressure relief valve, not shown here, the excess Flow the volume flow back into the tank (shock valve).

FIG. 3 shows a further possible embodiment of the inventive solution. Here, as a pilot valve 11 in an associated pilot valve body with four control nozzles 13 and an overflow opening to the drain line 20 according to T, a cylindrical rotary piston provided with internal bores and two eccentric grooves, one above the other, each arranged less than half the circumference and offset from one another by 180 °, is arranged as a control element 16 . The four control surfaces 18 of the cylindrical rotary piston are formed by the eccentrically arranged grooves therein and are connected via passage bores 19 to a bore arranged centrally in the rotary piston as a blind hole. This bore is connected to the drain line 20 to T via an overflow opening arranged in the pilot valve main body. The cylindrical control element 16, which can be rotated about its longitudinal axis, can be driven, for example, by a hand lever or else by a servo motor and thus, according to the invention, can control the motor 10 shown as a differential piston analogously to the explanations already given for FIG .

Another possible embodiment of the solution according to the invention is presented in FIG. 4. The pilot valve 11 is a conical one, arranged in an associated pilot valve body with four control nozzles 13 and an overflow opening to the drain line 20 according to T, with inner bores and two eccentric grooves arranged one above the other, in each case less than half the circumference and offset by 180 °, Rotary piston used as control element 16 . In this exemplary embodiment, too, the four control surfaces 18 are formed by the grooves arranged eccentrically in the conical rotary piston. These control surfaces are also connected to the drain line 20 to T analogously to the exemplary embodiment in FIG. 3. The advantage of this embodiment over the already explained embodiment according to FIG. 3 is that, due to the conical seat surfaces, the pilot valve shown in FIG. 4 hermetically closes the nozzle openings 13 in its "0" position. It is essential that, as also shown in FIG. 4, when using this hermetically closing pilot valve 11 , seals 21 are arranged in the valve block 1 between the valve bodies 2 , 3 , 4 , 5 and the sliding surfaces of the valve piston 7 assigned to them. Thus, in the "0" position of the control element, the seal 21 ensures that all control chambers 15 are hermetically sealed with respect to the "drainage space" in the valve body, thus avoiding the otherwise inevitable leakage losses and the pressure equalization that occurs as a result. The conical control element 16, which can be rotated about its longitudinal axis, can in turn be driven, for example, by a servo pulse motor and thus, according to the invention, control the motor 10 shown as a differential piston analogously to the explanations already given for FIG. 1.

The design shown in FIG. 5 now shows a further embodiment of the solution according to the invention. Here, the control surfaces 18 are realized by means of two thrust pistons with conical seats. In an assigned pilot valve body with control nozzles 13 and overflow openings to the discharge line 20 according to T, two conical thrust pistons, each with a bore 17 arranged in the piston crown, through which a radial through bore arranged in the cone region is guided, are arranged as control elements.

For "opening" or "closing", these conical control elements 16 are displaced translationally in the direction of their axis of rotation in the associated pilot valve chambers. This translational displacement of the control elements can again take place, for example, by means of thrust magnets or, as shown in FIG. 5, by means of a lever 23 . The control gaps between the control element and the pilot valve chamber change proportionally so that the control pressure for actuating the check valves according to the invention can be varied proportionally. Which in turn can also be controlled according to the invention by means of this design of the motor 10 represented as a differential piston, analogous to the explanations already given for FIG. 1.

Since this embodiment of the solution according to the invention with a seat valve also hermetically closes, seals are also arranged in the associated valve block between the valve body and the sliding surfaces of the valve piston. Thus, by means of the arrangement according to the invention shown in FIG. 5, the leakage losses in the control chambers when the pilot valve is in the “0” position and the pressure equalization taking place thereby can be avoided.

By means of the solution according to the invention, a hydraulic one has succeeded To develop control device, which with minimal manufacturing and Assembly effort without additional space requirement and even in connection with every standard connection plate (with standardized hole pattern) even  a defined path and speed controlled activation of a Differential cylinder with simultaneous implementation of a load holding function enables and also ensures a safety function, so that even if the valve spring of the 2-way on that loads the piston head breaks construction valve this always remains closed.  

Reference list

1

Valve block

2nd

1. Valve body

3rd

2. Valve body

4th

3. Valve body

5

4. Valve body

6

Valve spring

7

Valve piston

8th

cover

9

check valve

10th

engine

11

Pilot valve

12th

Pilot valve chamber

13

Control nozzle

14

Control line

15

Tax chamber

16

Control

17th

drilling

18th

Control surface

19th

Through holes

20th

Drain pipe

21

poetry

22

Compression spring

23

lever

Claims (9)

1. Hydraulic control device for the defined control of, for example, an engine using four 2-way cartridge valves, characterized in that in the piston head in the direction of the longitudinal axis of the spring-loaded valve piston of each 2-way cartridge valve, orifices with a diameter of approximately 0.05 mm up to 1 mm are arranged, whereby when the control nozzles are closed, the pressure from the connecting lines A, B and P builds up in the respectively assigned control chambers due to the orifices arranged in the valve pistons. 2. Hydraulic control device according to claim 1, characterized characterized in that in a preferred embodiment each valve piston has a difference between the piston surface and the seat surface of about 10%. 3. Hydraulic control device according to one or both of the claims 1 and 2, characterized in that the pilot valve with four path proportional opening control nozzles and an overflow opening to the drain line according to T. is provided, with all four in the "0" position of the control element Control nozzles are closed and according to the direction of displacement and depending on the respective displacement of the control element two control nozzles assigned to the corresponding direction of displacement as well as the control lines connected to them, from Displacement varies depending on the pressure in the control chambers, can be opened or closed cross-section synchronously.   4. Hydraulic control device according to one or more of the Claims 1 to 3, characterized in that in the connecting line the adjacent valve body for connecting the respective consumer A or B, a check valve immediately after the valve acted upon by P. can be arranged. 5. Hydraulic control device according to one or more of the Claims 1 to 4, characterized in that as a pilot valve in one assigned pilot valve body with four control nozzles and overflow opening for Drain pipe according to T a spring-loaded with conical control surfaces and Thrust pistons provided through holes arranged as a control element is. 6. Hydraulic control device according to one or more of the Claims 1 to 5, characterized in that as a pilot valve in one assigned pilot valve body with four control nozzles and overflow opening for Drain pipe according to T one cylindrical with inner bores and two over each other over less than half the circumference and eccentric grooves offset from each other by 180 ° provided rotary piston is arranged as a control element. 7. Hydraulic control device according to one or more of the Claims 1 to 6, characterized in that as a pilot valve in one associated pilot valve body with four control nozzles and one Overflow opening to the drain line according to T a conical, with inner holes and two on top of each other over less than half the circumference extending and offset from each other by 180 °  Eccentric grooves provided rotary piston arranged as a control element is. 8. Hydraulic control device according to one or more of the Claims 1 to 7, characterized in that between the valve body and the sliding surfaces of the valve piston seals can be arranged. 9. Hydraulic control device according to one or more of the Claims 1 to 8, characterized in that as a pilot valve in one assigned pilot valve body with control nozzles and overflow openings for Drain pipe according to T two conical thrust pistons with inner holes as Controls are arranged.