DE2137542A1 - Hydraulic valve - Google Patents

Description

Patent attorney DIPL.-PHYS. DR. W. LANGHOFF Attorney B. LANGHOFF ' MUNICH 81 -WISSMANNSTRASSE 14 · TELEPHONE 932774 · TELEGRAM ADDRESS: LANGHOFFPATENT MUNICH

Munich, 2f. JmIi 1971 Our mark; '64 -835

Hydraulic valve

The hydraulic valves with valve spindles that were previously known as Task comprise a shut-off valve which can be closed by a spring for, each drive opening and are dependent on a pressurized fluid, which from a pressurized fluid source to the outside flows through a forth drive orifices and both shut-off valves opens *

If the piston rod of the controlled motor is exposed to a strong external force in such a valve, does a large pressure fluctuation occur in the fluid path _? in which the shut-off valves are located. When the piston rod is accelerated, both by the pressurized fluid and by the external force, the high speed of movement of the piston rod causes the pressure drop on the fluid inflow path. This results in the drop in pressure holding the check valves open, and its check valves are immediately closed by the spring. This closing causes the piston movement to stop immediately and, as a result, a shock to the entire device. When the fluid from the source has accumulated sufficient pressure again, its shut-off valves are opened again and the cycle described repeats itself

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exactly affect the same force exerted and the Do not control the speed of the piston rod »which is all due to the above-described instability of the shut-off valves is due.

Efforts to date to address this difficulty and obtaining precise control of the piston rod movement made a significant limitation on the maximum possible volume of fluid to and from the controlled motor and an unhandy, complicated construction of. Shut-off valves necessary. These efforts resulted in a » suffered a great loss in the efficiency of the device and drastically limited both speed and speed the reaction time of the piston operation.

In accordance with the invention, the problem of the instability of the shut-off valves is solved by a separate pressure chamber and pressure-dependent devices,
1) to fully open both shut-off valves before any pressurized fluid from the pressure source is

drive opening can flow to the controlled motor. Z) to keep both shut-off valves open, regardless of pressure fluctuations that occur during the open engine

fluid circuit occur, and
3) to bottom both shut-off valves only when the fluid paths to and from the engine are closed.

Open and Closing the two shut-off valves does the same thing * - Stable drive, guarantees precise operation of the pluid dimensioning inside the valve stem, with the fluid flowing back from the controlled motor without any disturbance, he occurs due to pressure fluctuations that occur on

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of the path supplying the motor with pressurized fluid, and precise control of the movement and the location of the engine piston rod and the force applied to it.

According to the invention, the shut-off valves are not only kept closed by the pedal pressure, but also by the pressure of the iluid in the line between each Check valve and the end of the controlled motor attached to it. In addition, a bypass path is provided, to prevent accumulating internal loss of pressurized fluid from opening the check valve. This makes it possible that the two shut-off valves close the piston of the controlled motor in a certain position and he maintained in this position indefinitely.

The check valves built so far with double locking devices made the piston rod of the "float" Motor in one direction under the influence of an external force is not possible, as a drive opening in the open State would have to be connected to a pressurized fluid source, to open the two locking devices. Since according to this invention, the locking devices regardless of Flow fluid that flows to the engine, kept open becomes a "float position" for the flow control spindle created, with both ends of the controlled motor connected to a return line to a to ensure free movement of the engine piston in its cylinder.

The invention also includes a device for off-, nen both shut-off valves when the hydraulic pressure drops to NuIX, the one on the piston rod of the engine applied force could reach dangerous proportions. the

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Force can then be reduced to normal strength.

The invention is described below with reference to schematic drawings explained in detail?

Figure 1 is a vertical longitudinal section through a valve according to the invention, with the flow control spindle shown in its central position;

FIG. 2 is a cross section taken along line 2-2 of FIG Pigur 1;

Figure 3 is a partial view of the valve of Figure 1; and shows in detail another construction of the blocking valve Bach Figure 1;

Figure 4 is similar to Figure 1, but shows the flow control spindle moved slightly to the right from its neutral position, opening both shut-off valves for the pressurized fluid caused while the flow from the fluid inlet to one end of the engine through the Spindle remains blocked;

Figure 5 is similar to Figure 4 and shows the spindle moved further to the right to a position from which the fluid can be measured from the right end of the controlled motor and at the same time the flow of drive fluid from the fluid inlet to the left end of the engine is guaranteed, and

Figure 6 is an axial vertical section through a flow control valve according to the invention in slightly modified form, and shows a simple hydraulic system in which such valves can be installed.

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According to Pig. 1 and 2, the valve has a housing 1o a fluid inlet 11, fluid outlets 12 and 13, and two Drive ports 14 and 15, which nicely dep corresponding to opposite ends of a double-acting hydraulic motor 16 is connected * In the housing there is a valve spindle bore 17 »that of six Lines 18 and 23 arranged longitudinally and connected to this bore in addition to the fluid outlets 12 and 13 is surrounded. The lines 21 and 22 are with each other and connected to the fluid inlet 11. The lines 19 and 22 are connected to one another by a longitudinal connection 24.

In the valve spindle bore 17 is a flow control spindle 2J5, those of spaced-apart slits 26, 27 and 28 is attached, the latter Define projections 29, 3o, 31 and 32. The projections 29 and 31 are connected to fluid metering cams 33 and 34, as in FIG Figure 2 shown provided.

Inside is the flow control locker! 25 with a ball check valve 35, which closes off one end of the line 36. The ball return valve is flat * - if with the valve spindle bore by means of elongated, lateral lines 37 and 38 connected. The flow control spindle 25 has a second chamber 39 inside to »which is connected to the valve spindle bore through elongated, lateral lines 40 and 41.

The housing 10 is opposite the lockable by a spring Check valves 42 and 43> those with the opposite Opening pistons »44 and 45 by means of spindles 46 and 47 are connected. The shut-off valve 42 is located between the line 18 and the drive opening 14 and blocks the flow of fluid from the when closed

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Drive opening H in the line 18. The situation is similar Check valve 43 between line 23 and the drive opening 15, and blocks the flow of fluid from the drive opening 15 into the line 23 in the closed state.

The opening pistons 44 and 45 move see, in a pressure chamber back and forth, the one with an äer Ventilspindelbofc tion cooperating line 2o is connected. Inside are the opening pistons 44 and 45 with ball check valves 49 and 5o, which connect in one direction between the pressure chamber 48 and the flow lines 18 or 23 block.

A conventional valve spindle centering device 51 is connected to the left end of the flow control spindle 25 that which comprises a coil spring and which has the task of the flow control spindle in its neutral position (Pig. 1) to be brought back when the same is released. A spherical pin under spring tension 53j which is mounted in a recess in the housing, acts with an annular groove 54 near the end of the flow control spindle 25 together to put them in a "floating position", if desired, as detailed below befc wrote to keep.

Effectiveness

Gate of commissioning are the fluid inlet 11 with a hydraulic pump and the fluid outlets 12 and 13 connected to a container, not shown. If the Flow control spindle as in Pig. 1 occupies a neutral position, the pluid in and out of each other insulated, as are the two drive openings, and the Pistons and the piston rod of the motor 16 can move

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move in any direction β

To move the piston of the motor 16 to the right, the flow control spindle 25 is moved to the right. If this is yours in Pig. 4 has reached the position shown, pressure fluid flows from the inlet 11 through the line 36 to the ball check valve and through the lines 37-38 and 20 into the pressure chamber 48, which immediately results in the separation of the opening pistons 44 and 45 from one another, whereby this piston movement causes the shut-off valves 42 and 43 (FIG. 4) to open completely. When the spindle assumes the position described in Fig., The projection of the spindle blockert the flow of Druckfluis from the line 19 into the line 18 _r the spindle projection 31 blocks the flow of fluid from the engine through the conduit 23 into the fluid outlet. 13 The air pressure behind the shut-off valves 42 and 43 is released through atmospheric openings 55 and 56 provided with filters.

When the flow control spindle 25 moves to the right to the position shown in Figure 5, ensure the fluid dimensioning cams 34 at the left end of the spindle projection 3 »the precise metering of the fluid from the piston rod end of the motor 16 into the fluid outlet 13, and also ensures the left end face of the Spindle projection 30 allows pressurized fluid to flow from fluid inlet 11 through conduits 24 and 18 and out through the drive opening 14 to the left bath of the motor 16, Accordingly, the engine piston moves to the right under precise control by the valve actuation.

It should be noted that when the spindle has reached the position shown in Figure 5 or desires according to moved further to the right, the pressure chamber 48 in connection with the fluid inlet 11 via the lines

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36, 37 and 2o remains, and that the check valves 42 and 42 remain fully open, regardless of a fluid flow to or from the engine 16 through lines 18 and 23. Thus, the check valves remain unaffected by pressure fluctuations in the lines 18 and 23 or in the drive openings 14 and 15, and the precise measurement of the fluid " Auslasees through the spindle 25 and the exact control the speed of movement and the bearing of the piston of the motor 16 can proceed unhindered.

When the flow control spindle 25 is released, the valve spindle centering device 5 returns to the spindle back into its neutral position shown in FIG. When it moves into this position, the flowing of the Pressurized fluids to and from both sides of the engine 16 through the projections 3o and 31 blocked. Immediately thereafter, the two check valves 42 and 43 of their respective Springs closed and the fluid in pressure chamber 4948 flows through lines 41, 39 and 4o (Fig, 1) to fluid outlet 12.

In order to ensure that germs of the two shut-off valves 42 or 43 possibly enter the lines 18 or 23 If pressure fluid that has flowed is opened, secondary lines 57 and 58 (FIG. 1) are in the interior of the spindles 46 and 47 intended. The accumulated leakage fluid can through these lines 57 and 58 to the ball check valves 49 and 5o flow past into the pressure chamber 48, from where it flows back to the line 12, as previously described can. When the flow control spindle 25 moves from its neutral position (FIG. 1) to the left and the piston moved to the left, the same phenomena appear successively. The pressure fluid flows through first the lines 36, 37, 38 and 20 into the pressure chamber 48, and the opening pistons 44 and 45 open the shut-off valves 42 and 43 - as shown in Fig. 4 - completely, v / enn

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_ ο -

as the flow control spindle 25 moves further to the right, the pressurized fluid flows through from the fluid inlet 11 the line 23 and the drive opening 15 to the piston rod end of the motor 16, and at the same time metering of the fluid from the left end of the motor by the Pluid sizing cams 33 on spindle projection 29 in the fluid outlet 12 with the engine piston moving to the left under precise control.

Float position of the engine piston rod

When the flow control spindle has moved sufficiently far to the left that the spherical pin 53 engages in the annular groove 54, the pin holds the spindle against the spring force of the valve spindle centering device 51 temporarily in this position. When the spindle is in this position, it directs pressurized fluid from the fluid inlet 11, through line 36, the ball check valve and lines 38 and 20 to the pressure chamber 4-8, which maintains the check valves 42 and 43 fully open. _: The annular groove 26 connects the line 18 to the fluid outlet 12, and the annular groove 28 connects the line 23 to the fluid outlet 13. The spindle projection 30 shocks the flow of pressurized fluid from the fluid inlet into the line 23. In this position, the spindle connects the two open ends of the motor 16 with the low fluid outlets 12 and 13 and causes the piston and the piston rod of the motor 16 to move in one direction by external forces exerted on the piston rod.

One such "floating position" of the piston was ours Knowledge previously not possible with control valve spindles with double shut-off valves, because these are affected by the pressure fluid, which flows from the pressure source to one or the other engine end have been opened.

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Although not required in the valve according to the invention, can use an auxiliary shut-off valve to open the valve spindle centering device to be built in. This is only necessary in the case when the fluid pressure source is not works, which would result in the closing of the two check valves by the spring tension, which would then affect the piston at one end of the motor its possible revolution into an unstable one due to the force exerted on the piston rod and would hold dangerous condition.

To avoid such a condition, a usually solid sealed pin 59 is movably mounted in the valve housing to prevent fluid loss. The pin 59 has a generally conically shaped inner end which normally rests against the inner ends of the two orifice pistons 44 and 45 as shown in FIG. The pistons are pressed outwards, with the two check valves being free, which causes the motor piston to move in one direction through its force. The fluid displaced from one end of the motor 16 during this piston movement flows into the pressure chamber 48 through either conduit 57 or 58 (FIG. 1), as appropriate, and then out of the valve through the fluid outlet, as previously described.

Check valve construction according to Fig. 3.

Another check valve and piston design is in Fig. 3 shown. In this construction, the check valve 62 is attached similarly to the check valve 42, but not connected to the spindle 66 of the opening piston 64, although the piston spindle 66 is the check valve in the same way opens like. the spindle 46. The check valve 62 moves in a closed bore of a pin 85

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back and forth, this peg hole not having a vent valve as in the arrangement of the shut-off valves 42 and 43.

The shut-off valve 62 is provided with a lateral line 86 and an axial line 87 connected to it, which the flow of pressurized fluid from the motor opening H into the otherwise closed pressure chamber 88 behind the shut-off valve allows. With such a construction, the shut-off valve is opened by the one in the pressure chamber 88 creates pressurized fluid applied closing force greater than any pressurized force on the other end dee Check valve through the check valve plate 8a, because of the Force-exposed plate area is smaller than the entire cross-sectional area of the check valve. Thus becomes in this construction, the check valve 62 not only by the spring tension but also by the fluid pressure generated force held in a closed position.

In the valve shown in FIG. 6, the secondary lines 57 and 58 present in FIG. 1 are the ball check valves 49 and 5o and their branch lines are omitted. The opening pistons 44 and 45 are compact, and there are no secondary fluid outlets from the lines 18 and 23 into the pressure chamber 48

In the valve shown in Fig. 6, the flow from the fluid inlet 11 on the flow control spindle 25 past the neutral position of the same in the line 18 and via an additional spindle opening 90 (FIG. 6) the valve spindle chamber 39 and the opening 40 are drained into the fluid outlet 12. This is similar in the Line 23 accumulates fluid via an additional secondary line 91 which, when the flow control spindle is in the neutral position 25 is directly connected to the fluid outlet 13, drained.

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Thus, with the valve shown in FIG. 6, none are ordered Pluid connection between the pressure chamber 48 and the two lines 18 and 23 "

How the in Pig. 6 corresponds to that shown in Pig »1 to 5.

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Claims (1)

Claims )) Hydraulic control valve with a housing that has fluid inlets and outlets and two drive openings, with a valve spindle bore in the housing, with connecting lines in the same and with a flow control spindle movable in the valve spindle bore, which has slots spaced from one another and which limit the projections to the Controlling the flow of pressurized fluid to the drive openings and to the fluid outlets, characterized in that a pair of shut-off valves (42, 43) are switched on in the lines (18, 23) leading to the motor (16) and the drive openings (14 * 15) with the valve stem bore (17) connecting that a pressure chamber (48) is provided in the housing (10) axially aligned with the two opposing non-return valves, wherein the open sides of the pressure chamber (48) is respectively arranged adjacent to a check valve, that a pair of opening piston ( 44, 45) are movably arranged in the pressure chamber (48) and when pressure is applied The shut-off valves open, that a line (20) is connected to the pressure chamber (48) for supplying pressure fluid, and that the flow control spindle (25) has a fluid channel system for supplying pressure fluid into the line (20) and the pressure chamber ( 48), and that the flow control system is designed so that a connection to the fluid inlet (11) is present when a line (18, 23) leading to the motor is connected to the fluid inlet via the slots (26, 27). 109886/1338 2,) control valve after. Claim 1, characterized in that that a check valve (35) is arranged in the Fluidlaitsystem, which is opened by the inlet fluid pressure. 3.) Control valve according to claim 1 or 2, characterized in that the fluid control system is designed so that it is in the neutral position of the flow control spindle (25), the flow blockage corresponds to the pluid outlets (12, 13) and the line (20) is in communication. 4.) Control valves according to claim 1 to 3, characterized characterized in that the flow control spindle (25) is movable into a floating position is and that the flow control system then a connection between the fluid inlet (11) and the pressure chamber (48). 5.) Control valves according to claim 3 or 4 »thereby characterized in that in each of the opening pistons (44 »45, 64) one of a check valve controlled line (57 »58) is provided, which in the neutral position of the flow control spindle (25) enables a leakage flow from the lines (18, 12) leading to the motor (16) into the pressure chamber (48) and a reverse flow ic blocked. 109886/1338