JPH086723B2 - Hydraulic control device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a hydraulic control device of the type described in the preamble of claim 1.

[0002]

PRIOR ART AND PROBLEMS TO BE SOLVED BY THE INVENTION 800
0 Munich 80, published 7 June 1986, edited by Heilmeier and Weinline 7100
In hydraulic control systems, as is known from pages 1 and 2, the damping throttle provides a controlled closing movement or a controlled opening and closing movement of the load holding valve in order to damp the pressure fluctuations of the device and thus the vibration of the load. Must be dampened. The function of the load-holding valve is that the undesired or unacceptable after-running of the hydraulic consumer under load after the hydraulic consumer has been stopped.
g) is to be prevented. A control device of this type equipped with a damping throttle can be used for all types of lifting with a change in the indication of the load direction, for example in lifting or extension cylinders of cranes, in particular vehicle cranes, in rotary piston cylinders or rack / pinion pivot cylinders. It is preferably used when the oscillating movement of the hydraulic consumer has to be expected, in the upper and pivoting means, such as in cable-winches or pivot mechanism drive means. The damping throttle is set such that in the case of an operatively warm pressure medium, when the load holding valve is opened and the hydraulic consumer is moved under load, it damps pressure fluctuations optimally. Within the load holding valve there is a working clearance associated with the movement of the relatively small pressure medium volume in the control pressure conduit. These volumes pass through the damping throttle and create a damping effect within the device.
Damping throttles provide the desired rapid closing movement of the load holding valve for stopping or positioning of the load due to the setting of the selectively tight damping throttle to achieve optimum damping and / or in the case of cold pressure medium. May delay. As a result, the hydraulic consumer consumes harmful or dangerous after-motion after stopping under load.
run).

As is known from DE 3733740 A1, in this type of hydraulic control device the load lowering valve consists of two throttle gaps arranged in parallel inside the control pressure conduit of the load lowering valve with the aid of laminar flow. Controlled through. The two throttle gaps are matched to each other with respect to their linear characteristic so that their summing characteristic substantially follows the desired characteristic curve in the operating range. Two
Throttle gaps change their gap height in response to temperature. A vibration damping action independent of the temperature of the pressure medium is thus aimed at. This principle is also suitable for load holding valves. The gap height of the two throttle gaps designed for optimum damping in the case of a cold pressure medium cannot eliminate after-running of the hydraulic consumer when a load holding valve is present.

This type of hydraulic control device is often integrated in a hydraulic system with a safety shut-off function. This is a hydraulic consumer, or a component that is moved by it,
Is monitored for load limits, load moment limits or motion limits that must not be exceeded. The limit pressure or limit position sensor produces an electrical signal that opens a solenoid valve in the control circuit. This valve reduces the opening pressure for the control means of the control valve of the hydraulic consumer or for the main control means of the hydraulic system. Further movement of the hydraulic consumer above this critical limit should be prevented by no longer delivering effective pressure in this direction of movement or by limiting the amount of effective pressure medium. However, it often happens that the sensor responds to this safety limit only in a precise manner, or at best within a relatively narrow predetermined tolerance range. If the hydraulic consumer exceeds the tolerance range despite the response from the sensor, e.g. due to backward movement of the hydraulic consumer under load, the sensor no longer responds and the hydraulic consumer is within the critical range. Can be controlled without any restrictions. In cranes, for example, this is particularly dangerous for vent cylinders or horizontal pivot cylinders, and above all, as has been found in practice, strong damping effects in the case of cold pressure media or by standard installed damping devices. See below.

The object of the invention is a hydraulic control device of the type mentioned above, in which undesired back movements of the hydraulic consuming device are eliminated under load despite a damping action for normal operation. Or to improve the hydraulic control device by means of a safety shut-off means with regard to the reliability of its safety function even under adverse conditions.

[0006]

According to the invention, said object is achieved by the features indicated in the characterizing part of claim 1.

If the hydraulic consumer, or rather the load, should be lowered by releasing the pressure medium from the working conduit containing the load holding valve, the opening pressure is delivered in the control pressure conduit and the load holding. The valve is opened in a controlled manner. The valve arranged in the conduit loop maintains its closed position; the pressure medium passes through the damping throttle and is damped. Whenever the hydraulic consumer is to be shut down, the control pressure conduit is depressurized until the load holding valve closes in a controlled manner and holds the load. In the case of cold and therefore viscous pressure media, the valve responds to the resulting pressure differential and assumes its through position in order to ensure a satisfactory and rapid closing of the load-holding valve. The pressure medium bypasses the damping throttle. Similarly, in the case of a selectively throttled damping throttle to achieve the desired damping action and in the presence of an operationally warm pressure medium, the valve must be deactivated by the hydraulic consumer and The load must be held and responds whenever the damping throttle will prevent such effects. The responsiveness of the valve is such that under adverse operating conditions any after-running of the hydraulic consumer is prevented and when the damping throttle is nevertheless required damping action, for example the load is lowered. When is always adjusted to perform such an action. The hydraulic controller may automatically disable the damping throttle whenever there is an operating condition that is critical with respect to the back movement of the hydraulic consumer along with the valve. This provides the benefits of a damping throttle that can be optimally adjusted for damping and the quick response and load retention benefits of the load retention valve in operating conditions where the damping throttle interferes with the controlled closure of the load retention valve. If a safe cut-off is ensured in the hydraulic system including the hydraulic control, the hydraulic consumer cannot exceed the safety limit or pass the safety tolerance range even under adverse conditions.

In an embodiment according to claim 2, the second pressure difference at the valve is such that when the load holding valve has almost reached its load holding position and only a small amount of effective pressure medium has passed through it. Is adjusted to allow the pressure throttle to regain its maximum effect. The residual closing lift of the load-holding valve can be monitored again by means of a damping throttle, which can perform an independent damping action when pressure oscillations occur.

In the embodiment of claim 3, the pressure in the control pressure conduit initially maintains the valve in the closed position when the load holding valve is open. This pressure overcomes the force permanently acting on the valve. Even with non-extreme pressure fluctuations, the valve element remains in the shut-off position, so that the damping throttle damps the load-holding valve play and pressure oscillations in the hydraulic system. If the pressure in the pressure control conduit is reduced by the damping throttle to such an extent that the permanently acting force moves the valve in a controlled manner to the through position.
The pressure reduction which allows a precise and controlled closing movement of the load holding valve is ensured by the pressure medium flowing through the valve.
Due to the pressure medium flowing through the damping throttle at any flow rate, the valve will only move to the through position under normal operation if any back movement of the hydraulic consumer must be of any concern. In contrast, when excessive pressure fluctuations are present, the valve may also be moved to the position for a short time in a controlled manner, thus supporting the damping action of the damping throttle by reducing the pressure peaks. However, permanent force will immediately return it to the blocking position.

The embodiment according to claim 4 has a simple structure. The pressure difference between the opening pressure and the elastic force acting on the valve element is passed through the damping throttle at an arbitrary flow rate. The responsiveness of the valve is adjusted by the choice of this pressure difference, so that the damping throttle operates mainly with non-extreme pressure fluctuations in the system, while the damping throttle allows the reliable stopping of the hydraulic consumer under load. And, when needed in the presence of cold pressure medium, it is automatically ignored to the required limit.

The features of the embodiment of claim 5 are also important because the sliding valve does not leak oil without requiring any significant structural work and operates in a relatively temperature independent manner. is there.

In an embodiment of claim 6, the biased closed check valve also works under load, in the rising pressure window during movement of the hydraulic consumer, ie the pressure difference at the damping throttle causes the check valve to move. At the same time as it becomes larger than the acting permanent force, the pressure medium is such that the permanent force must close the closing check valve again and the remaining pressure medium must flow through the damping throttle from the open side of the load holding valve. Flow off through the damping throttle until the pressure differential decreases. The desired effect here is to substantially stop the hydraulic consumer before the load-holding valve closes rapidly in a forceful movement and before the load-holding valve moves to its closed end position in a subsequent damped residual lift movement, The passage in the working conduit is already somewhat restricted in the working conduit. Thus, not only are pressure fluctuations suppressed or dampened, but the load holding valve is also very reliable in a controlled manner (especially in the case of safe shut-off operation) and from operating conditions (including cold pressure media). Independently and rapidly beyond the safety limit or through the safety tolerance range, the movement of the hydraulic consumer closes so fast that no movement occurs.

It has been found that the embodiment of claim 7 is practically useful. With such an adjustment, the rearward movement of the hydraulic consumer under load is prevented even in the case of tight settings of the cold pressure medium and the damping throttle.

In the embodiment of claim 8 the relatively strongly biased closing check valve allows a substantially unobstructed action of the damping throttle. Because it is only valid if there is an unacceptable risk of movement of the hydraulic consumer, and it is immediately switched off again when this risk is eliminated after a strong controlled closing movement of the load holding valve. Because it does.

Another advantageous embodiment emerges from claim 9. Especially in vehicle cranes, strong vibrations of load can be practically observed. These vibrations cause long lasting pressure fluctuations in the hydraulic system and make the crane more difficult to operate. Therefore, the damping effect of the motion damping throttle is no longer satisfactory. By-pass conduits and obstructing throttle passages located therein and co-operating throttle passages in the control pressure conduits make it possible for the additional hydraulic damping device to very effectively and quickly dampen pressure fluctuations. Incorporated into the control circuit of the valve, the amount of pressure medium flowing off through the bypass conduit interferes with the amplitude of the pressure oscillations to the extent that pressure fluctuations are soon dampened. The inclusion of different pressures (the pressures prevailing in the control circuit of the load-holding valve) into the pre-control means of the valve subjected to a permanent force is due to the critical operating conditions (cold pressure medium and / or tightly set movements). It provides the benefits of a load retention valve that is closed immediately even under damping throttle).

The permanently acting force may be relatively small in the embodiment of claim 10 because it is supported by the pressure in the bypass conduit. This improves the response characteristics of the valve. Since the valve participates in damping the pressure fluctuations, this has the additional benefit that the dimensional difference between the throttle passage and the obstructing throttle passage can be made very small, whereby the amount of pressure medium flowing out through the bypass conduit is reduced. , Can be kept as small as desired.

The features of claim 11 are also important. The volume flow required for valve damping and pre-control is
In fact, it must be possible to flow off through the bypass conduit in order to contribute to the damping action.
The bypass conduit is preferred if the control valve, which establishes the connection between the tank and the two working conduits or the tank and the working conduit with the load holding valve in the zero position, is integrated in the hydraulic control device. Is connected to said conduit.
Alternatively, the bypass conduit can also be directly connected to the tank. In such cases, a directional control valve with a blocked zero position may also be used. And also, a directional control valve with an inflow controller can be used because of its effective damping action, but it usually has a rather long transient response, which makes it adventurous for oscillating controllers. Is.

Furthermore, the embodiment of claim 12 is such that the bypass check valve for controlled opening bypasses the damping throttle for the immediate controlled opening of the load holding valve desired for certain applications. It is convenient because it enables it. In the case of pressure oscillations during the movement of the hydraulic consumer, this check valve is kept closed by the pressure in the control pressure conduit at any flow rate, so that the control pressure medium must flow through the damping throttle. I won't.

An embodiment which is structurally simple is described in claim 13. The check valve is integrated into the valve and ensures a controlled opening of the load holding valve without causing delay.

The embodiment of claim 14 is characterized by a particularly effective damping of pressure fluctuations in the hydraulic system.
The operation of the closed check valve is advantageously influenced by the pressure accumulator.

Furthermore, the embodiment of claim 15 is advantageous. A check valve provided at this point prevents the control pressure medium from escaping into the other working conduit, or
Prevents pressure fluctuations in the control pressure circuit from propagating into the other working conduit. Furthermore, the check valve forces the pressure medium from the pressure accumulator to flow off through the bypass conduit for effective damping action.

The embodiment of claim 16 is such that a simple safety shut-off device cannot even be tricked under adverse operating conditions such as a strong damping action by a cold pressure medium or a tightly set damping throttle, and the load holding valve is It has the particular importance of being independent as it closes as desired without any discernible back movement. At the safety shut-off point, the closed check valve may be biased less strongly, while within the safety shut-off tolerance range it may be biased to a greater extent. The reliability of the safety shut-off action is also ensured under completely right conditions for normal operation, which are particularly disadvantageous for the safety shut-off action.

The embodiment of claim 17 provides a simple construction of the safety shut-off device, since each sensor, just like the relief valve, only needs a power supply means which can be easily accommodated. The relief valve has small dimensions and can be integrated in the directional control valve or control means without any problems.

In all of the embodiments described above, the valve as well as the additional components can be installed directly in the block of the load holding valve. However, by mounting the unit on the load-holding valve as a retrofit unit, or placing it elsewhere in the control circuit of the load-holding valve and modifying a previously operating or previously designed control device, It can also be renovated.

In the following, embodiments of the inventive subject matter will be described with reference to the accompanying drawings.

[0026]

Example: A load arm carrying a load F, for example a vent cylinder of a vehicle crane.
r), a hydraulic power consuming device V, for example a double-acting hydraulic cylinder, can be found in the hydraulic control device S as shown in FIG. A double-acting hydraulic cylinder having two chambers 2, 3 separated by a piston is supplied with pressure medium from a pressure source P from a tank T. A control valve C is installed to control the hydraulic power consumption device V.
In the illustrated embodiment, this is the reduced pressure zero position (reli).
4 / with an embedded zero position)
It is a three-way control slide. The chambers 2, 3 of the hydraulic power consumption device V are connected to the control valve C via working conduits 4, 5. When pressure acts on the working conduit 4, the load F is lifted and the pressure medium is discharged through the other working conduit 5. When pressure acts on the other working conduit 5, the hydraulic consumer V is moved (lowered) under load F and the pressure medium is discharged through the working conduit 4. One of the working conduits 4 has a load holding valve H arranged therein, which serves to hold the load F, for example in the zero position of the control valve C. The load holding valve H has a valve member 7 which is provided with a valve 6 which is continuously adjustable between a passing position and a closing position with respect to a control valve C according to a conventional method and which has an open position (not shown). The valve member 7 has a spring 7'in the closed position (not shown).
Loaded by Furthermore, the pre-control pressure transmitted via the control line 9 acts on the side of the control valve C in the closing direction. In the open position, by contrast, the pre-control pressure acts in the control line 8 branching from the action line 4 between the valve 6 and the hydraulic consumer V. Furthermore, a control pressure conduit 12 is provided. The pressure in the control pressure conduit acts on the valve member 7 in the opening direction. The control pressure conduit 12 branches from the working conduit 5 in this embodiment. However, it is also possible to supply pressure to the control pressure conduit 12 from an independent pressure source or pressure control device.

The load holding valve H is bypassed (for lifting purposes) by a bypass line 10 having a check valve 11 which opens towards the hydraulic consumer V.

Pressure fluctuations during the downward movement of the load F and, in the present embodiment, an adjustable damping throttle 13 which damps the controlled opening and closing movement of the valve 6 is included in the control pressure conduit 12. The conduit loop 14 is a control pressure conduit 12
Bypass the damping throttle 13 provided in the. The conduit loop 14 is arranged in FIGS. 1 to 5 with a valve having a valve element 16, a reversible 2 / 2-way slide valve between a passing position a and a blocking position b. Valve element 16
Is acted upon by a permanent force f of the spring 18, which can be adjusted freely towards the threaded position a. In contrast, valve element 1
6 is acted upon by the pressure in the precontrol conduit 17 towards the shut-off position b. The pre-control conduit 17 branches off from the conduit loop 14 between the valve 15 and the other working conduit 5.

The force f is a little less than the force acting on the valve element 16 through the (open) pressure in the pre-control conduit 17.

To lower the load F, the working conduit 5 is acted upon by the pressure from the control valve C. Since the check valve 11 closes, the valve 6 must be opened in a controlled manner. This is achieved through the control pressure conduit 12 and the damping throttle 13. The pressure in the control pressure conduit 12 holds the valve 15 in the closed position through the pre-control conduit 17, so that the pressure medium passes across the controlled opening actuation damping throttle 13. If pressure fluctuations are later observed in the hydraulic system during the lowering movement, the valve 15 remains in its closed position, at least in the case of a non-extreme pressure fluctuation. Effective play of valve 6 (for example, 1/10 m
During the range m), the pressure medium is damped by the damping throttle 13.

If the load F should be stopped, then
The pressure in the other working conduit 5, and thus the control pressure conduit 12, is relieved. If the pressure at the valve member 7 cannot be relieved quickly enough due to the controlled closing of said valve member via the damping throttle 13, the spring 18 bypasses the damping throttle 13 via the conduit loop 14. The valve element 16 into the threading position a, so that the valve closes rapidly. This prevents any after-running of the hydraulic consumer V. Valve 15
Whenever the damping throttle 13 delays a controlled closing movement due to the viscosity of the cold pressure medium, or whenever the damping throttle 13 is set very tight for sufficient damping action, validate. Furthermore, when there is excessive pressure fluctuation in the control pressure conduit 12, the valve 15 can be switched to the short passageway to participate in the damping action and pass the pressure peak. The spring 18 moves the valve 15 to the closed position even before the pressure in the control pressure conduit 12 is completely relieved. The residual pressure is released through the damping throttle 13. The valve 15 performs the auxiliary closing function in the same way as with the rising pressure window.

The hydraulic control device S shown in FIG. 2 is an additional conduit loop 19 of the control pressure conduit 12 which has a check valve 20 which opens in a controlled manner towards the valve 6 between the controlled opening of the valve 6. It differs from the embodiment shown in FIG. 1 by having one arranged to prevent any delay. In the case of pressure fluctuations during the downward movement, the check valve 20 is held in the closed position, so that the momentum of the control pressure medium passes through the damping throttle 13. The other functions of the hydraulic control device shown in FIG. 2 are the same as those shown in FIG.

In the embodiment shown in FIG. 3, the check valve 20 is structurally integrated with the valve 15 'and its valve element 16'. The function is the same as that in the embodiment shown in FIG.

The hydraulic control S according to FIG. 4 differs from the embodiment of FIG. 2 by having an additional damping device X for pressure fluctuations in the system. The damping device X includes a throttle passage D ₁ in the control pressure conduit 12 and a control pressure conduit 1
Bifurcate at 2 to 21 and block throttle passage D
₂ by-pass conduit 22. The disturbing throttle passage D ₂ is larger than the throttle passage D ₁ . The bypass conduit 22 is connected (at 23) to the working conduit 4 or is directly connected to the tank T, as indicated by the dashed line 24, so that the working conduit 5 and thus the control pressure conduit 12 are under pressure. At this time, the pressure medium steadily flows out through the bypass conduit 22. The passages D ₁ and D ₂ connected in series have an additional damping effect on the pressure fluctuations as the control pressure medium flows away.

In the opening direction, the damping throttle 13 is bypassed by the check valve 20. Conduit loop 14
Is arranged with its valve element 16 ", which ensures a rapid closing of the valve 6 under adverse operating conditions (cold pressure medium and / or tight regulation of the damping throttle 13). Valve element 16 "is a load toward the through position a by the pressure in the spring 18 and the pilot control conduit 26 having a permanent force. Downstream of disturbance throttle passage D _2, the pilot control conduit 26 is a bypass conduit 22 from the control pressure conduit 12 to the shut-off position b by means of the pressure prevailing between the connection point of the bypass conduit 22 and the damping throttle 13. Pressed. The force f regulated by the spring 18 may be relatively small in this embodiment because the spring 18 is supported by the pressure in the pre-control conduit 26. At the opening pressure of 20 bar required in the valve 6, the setting of the spring 18 to a pressure value of 15 bar will result in any backlash in the case of a cold pressure medium and / or an overly tightly regulated motion damping throttle 13. It is sufficient to ensure a rapid closing of the valve 6 without causing any after-running. Valve 1
Since the 5 "supports damping of pressure fluctuations, the obstructing throttle passage D ₂ need only be slightly larger than the throttle passage D ₁ so that the amount of pressure medium flowing out through the bypass conduit 22 is in the desired manner. Is kept small at.

The function of the hydraulic control device S according to FIG. 4 is substantially the same as that in FIG.

In the modified embodiment shown in FIG. 5, the check valve 20 as shown in FIG. 4 is structurally integrated with the valve element 16 "of the valve 15"". Pre-pressure control of valve 15 "'is accomplished in the same manner as in FIG.

The valves 15, 15 ', 15 ", 15"' do not necessarily have to be sliding valves, but sliding valves have the advantage of virtually oil-free operation. The desired function may also be achieved by a seat valve or a biased openable check valve.

Furthermore, when the pressure medium is cold, for example, or because of a delayed decompression, or when the pressure prevailing on the open side of the valve 6 rises excessively because the pressure is not reduced sufficiently quickly. Can be actuated by a magnet at any time and operated by a remote control via a thermostat or a pressure control device 15,1
It is also possible to configure 5 ', 15 ", 15"'.

In the embodiment shown in FIG. 6, the hydraulic control device S has a damping throttle 13 in the direction away from the valve 6.
It has a closed check valve as a valve 15 ^IV for bypassing the valve.
The check valve blocking element 16 ^IV is biased towards the seat 28 by a bias-adjustable spring 18. The closing check valve causes the permanent force f of the spring 18 in the direction away from the valve 6.
Open against. The spring 18 is set to a bias value which is slightly less than the value of the force acting on the blocking element 16 ^IV through the opening pressure. At an opening pressure of about 40 bar, the spring 18
Force of at least 15 bar and preferably about 25 bar. The function of the hydraulic control device S is equivalent to the function of the embodiment shown in FIG. But again, the second
It is also possible to dispense with the check valve 20 in the conduit loop 19 of FIG. The functioning of the hydraulic control device S according to FIG. 6 is therefore equivalent to the functioning of the embodiment shown in FIG. 1, except that the damping device X is additionally provided in FIG.

Unlike the embodiment shown in FIG. 4, the bypass conduit 22 of the damping device X is connected to a return conduit 24 which is directly connected to the tank T. One working conduit 4 is here also connected to the return conduit 24 via a relief valve 27. Furthermore, a filter 29 is arranged in the control pressure conduit 12 . Furthermore, a non-return valve 32, which shuts off towards the other working conduit 5, is arranged on the side of the control pressure conduit 12 facing the other working conduit 5 (not shown). Furthermore, additionally contact at the connection point 21 accumulator 31 is via a conduit 30
Will be continued . The damping device X including the storage device 31 is also deleted.
You can Further, the storage device 31 reduces the damping device X.
With optional features to improve the damping effect
However , since it is possible to provide the damping device X that does not have it, it is not always necessary .

If the control pressure conduit 12 for closing the load holding valve H is not acted upon by pressure, the check valve 32 closes. The pressure in the control pressure conduit 12 is released through the bypass conduit 22 into the return conduit 24. If the pressure difference increases in the damping throttle 13 to such an extent that the controlled closing movement of the valve 6 is delayed, for example due to a cold pressure medium or a tight regulation of the damping throttle 13, the force f of the spring 18 is overcome and the The check valve for control closure is opened. The valve element 7 of the valve 6 of the load holding valve H is
It performs a strong lift in the closing direction until it is almost in the closed end position. The load and hydraulic consuming device is stopped. If any, a negligible amount of working pressure medium now flows off valve 6. The spring 18 acts on the blocking element 16 ^IV , the pressure difference dampening the throttle 13
After being correspondingly reduced at, the contact with the seat 28 is made again.
The control pressure medium is used to lift the remaining lift of the valve element 7.
It is propelled through the damping throttle 13 through t).
The controlled closing movement of the valve 6 takes place in two stages which are continuous with one another in a coordinated manner, the first longer stage being caused by the closing check valve and the second shorter stage being caused by the damping throttle 13. No significant after-running of the hydraulic consumer is observed in this case. The response characteristics of the load holding valve H are required for damping and are adjusted for optimum damping. The damping throttle is closed by a non-return valve so that the damping throttle is probably not defeated under adverse operating conditions causing back movement. It can be adjusted more or less. This is particularly advantageous, for example, when the movement of the hydraulic consumer or the components actuated by it in the safety circuit is to be prevented or only tolerated to a precisely determined limit.

FIG. 7 illustrates the incorporation of the hydraulic control S in a hydraulic system K with a safety shut-off device A, for example a crane. The safety shut-off device A prevents further movement of the hydraulic consumer device V at the load limit, the load moment limit or the limit of movement in the direction in which such a limit is reached. The hydraulic power consumption device V in FIG. 7 is, for example, a vent cylinder of a crane. The reference point 33, which is outlined in the hydraulic consumer V, must not pass beyond the limit indicated by the shaded area 34. Instead of movement limits, pressure or moment limits can also be monitored. The sensor 43 senses the reference point 33 and produces a signal as soon as the reference point 33 reaches the shadow area 34. If the line shadow area 34 is again separated by the reference point 33 in one direction or the other, no signal is generated.

The working conduits 4 and 5 are connected to a control valve C which is constructed as a directional control valve and is supplied with pressure medium by a pump P and which is at the same time connected to a tank T.
A control means, for example in the form of a suction controller Z, which supplies the control valve C with the amount of pressure medium required to completely control the hydraulic consumer V in response to the load pressure, is arranged on the suction side of the control valve C. It For this purpose, the control means Z is actuated in the closing direction by the pressure upstream of the control valve C through the preliminary control conduit 41, while it is controlled by the control conduit 37.
Through the load pressure in the working conduit 5 and in the opening direction by the control spring 42. This is the conventional pressure balance principle.

Control means Z instead of the suction controller
Is also a main controller that regulates the suction pressure or flow rate in the common supply conduit in response to the maximum demand or priority of the selected hydraulic consumers when there are multiple hydraulic consumers supplied by the same pump P. Can also be configured by.

Located in the control conduit 37 is a relief valve 36, which is preferably configured as a solenoid valve with a shut-off position spring 39 for a solenoid 38 and a valve element 40.
Solenoid 38 receives a signal from sensor 43 into conduit 35 and depressurizes control conduit 37 at the same time reference point 33 enters shaded area 34. The control means Z interrupt the further supply to the control valve C. The pressure in the working conduit 5 is no longer increased. When the safety shut-off device A responds, the load-holding valve H shown on the left side of FIG. 6 is thus such that the hydraulic consumer device V is not allowed to make any movements while its reference point 33 passes through the shadow area 34. It must be closed quickly. The valve 15 ^IV of the left load-holding valve H is adjusted by its spring 18 so that it guarantees a rapid closing of the load-holding valve H which is coordinated with the shaded area 34.

The load holding valve H shown on the right side of FIG. 7 serves for load holding purposes in other directions of movement of the hydraulic consumer V. This is not shown in FIG. 7, but said direction of movement of the hydraulic consumer V can also be monitored by the safety shut-off device A. In this case, one working conduit 4 also has a control means Z.
Must be in pressure control communication.

[Brief description of drawings]

FIG. 1 is a diagram showing a hydraulic control device in a load holding position.

FIG. 2 is a diagram showing a modified embodiment of the hydraulic control device in the load holding position.

FIG. 3 is a diagram showing a modification of the details of FIG.

FIG. 4 is a diagram showing another embodiment of the hydraulic control device.

FIG. 5 is a diagram showing a variation of the details of FIG.

FIG. 6 is a diagram showing yet another embodiment of the hydraulic control device.

FIG. 7 is a diagram showing a hydraulic control device having a safety cutoff device.

[Explanation of symbols]

 S hydraulic control device V hydraulic consumption device H load holding valve C control valve X damping device 4 working conduit 5 working conduit 12 control pressure conduit 13 damping throttle 14 conduit loop 15 valve 16 valve element 17 preliminary control conduit 18 spring 19 conduit loop 20 reverse Stop valve 22 Bypass conduit 31 Accumulator 32 Check valve 36 Relief valve 43 Sensor

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location F15B 21/04 A (56) References JP-A-55-132401 (JP, A) Actual development Sho-53 -87393 (JP, U) Actual development Sho 59-47167 (JP, U) West German patent 3733740 (DE, B)

Claims (17)

[Claims] 1. A return type hydraulic power consumption device (V), comprising:
It is actuable by pressure through two working conduits (4,5) and is blocked in at least one working direction by a load holding valve (H, H ') provided in the first working conduit.
The load holding valve includes
Connect the control connection of the load holding valve (H, H ') to the second working conduit.
Via a control pressure conduit (12) connected to (5)
Controlled by the control pressure obtained from the two conduits (5)
Can be opened and closed by hydraulic pressure in a different manner, and the opening movement of the load holding valve in the control pressure conduit (12)
A hydraulic control device comprising a damping throttle (13) for hydraulic damping , wherein valves (15, 15 ', 15 ", 1 in said control pressure conduit (12) in parallel with said damping throttle (13).
5 ″ ′, 15 ^IV ) provided with the valve in the closed position (b)
And the through position (a) can be switched between
Is mechanically biased toward its blocking position and
The effective pressure difference at the deceleration throttle (13) and
Acting on the valve in its switching direction towards the through position
Due to the mechanical bias opposite the pressure difference, its cutoff position
The pressure difference at the throttle valve is
Higher pressure in the second working conduit (5) and
Lower pressure at the control connection of the load holding valve
The mechanical bias of the valve is set by the pressure
At the value corresponding to the first value of the difference,
Accordingly, the pressure difference is predetermined and the second action is
The damping throttle is regulated in the direction of flow towards the conduit (5).
When descending to the first value to bypass, the valve
Automatically switches from the shutoff position to the through position,
The pressure difference below the first predetermined value.
A hydraulic control device characterized in that the valve is automatically maintained unless it is lowered. 2. The hydraulic control device according to claim 1, wherein the valves (15, 15 ′, 15 ″, 15 ″ ″, 15).
^IV) is, in response to pressure, the shut-off position from the through position (a) to (b), the second value of the first value is less than the pre-determined pressure difference before Ki圧 force difference A hydraulic control device characterized by being capable of automatic reverse rotation. Wherein any one of claim 1 or claim 2
The hydraulic control device according to claim 1, wherein the control pressure conduit (1
A valve element (16, 2), in which a conduit loop (14) bypassing said damping throttle (13) is arranged and moved between said passing position (a) and said blocking position (b); 16 ', 16 ", 16"') having said valve (15, 15 ', 15 ", 15"') arranged thereon , said valve element (16, 16 ', 1)
6 ″, 16 ″ ″) are directed to their shut-off position (b) by the prevailing opening pressure in the control pressure conduit (12) on the side of the damping throttle facing away from the load holding valve (H). act Te is and that through position by a permanent force to be adjusted (f) to a value less than the value of the opening pressure force of the load holding valve that acts on the valve element (H) (a)
And a hydraulic control device. 4. The hydraulic control device according to claim 3, wherein the valve element (16, 16 ′, 16 ″, 16 ″ ″) is loaded by a spring (18). hydraulic control device according to claim and this but is adjusted by opening pressure force, for example, 20 bar for the value that corresponds to about 15 bar in the valve element. 5. The hydraulic control device according to claim 1, wherein the valve (15, 1)
5 ', 15 ", 15"' are said valve elements (16, 1)
6 ', 16 ", 16"') is a slide valve having a piston slide forming a hydraulic control device. 6. one of claims 1 or claim 2 1
A hydraulic control device according to paragraph (1), in which the control pressure conduit (12) is arranged with a conduit loop (14) bypassing the damping throttle (13) and is configured as a closed check valve (15 ^IV ). a valve having a blocking element (16 ^IV) which is a so that to movement between the blocking position and the threading position with the flow direction away from said load holding valve (H) there is arranged on it, said blocking Element (16 ^IV ) is a permanent force (f), for example less than the value of the force of the opening pressure of the load holding valve (H) acting on the blocking element (16 ^IV ) which is an adjustable spring (18). hydraulic control device according to claim that you are pressed resiliently polarized towards its blocking position by an adjustable spring which is set to. 7. The one of claims 3 or claim 6 1
In the hydraulic control device according to the paragraph (3), the permanent throttle (f) opens the load holding valve, so that the damping throttle (13).
And the load holding valve (H) between the control pressure conduit (1
A hydraulic control device characterized by being limited to a value that is 10% to 50% smaller than the value of the opening pressure force required in 2). 8. The hydraulic control device according to claim 6, wherein the spring (1) is provided with an opening pressure of 35 to 40 bar.
Hydraulic control device, characterized in that 8) is set to a force value corresponding to about 25 bar in the blocking element (16 ^IV ). 9. The hydraulic control device according to claim 1, wherein the throttle passage (D ₁ ) faces away from the load holding valve (H). 13) on the side of the control pressure conduit (12) , a bypass conduit (22) from the control pressure conduit (12) between the throttle passage (D ₁ ) and the damping throttle (13). branched and hydraulic control device comprising a call having the throttle path (D ₁₎ greater than interference throttle passage (D _2). 10. A hydraulic control device according to any one of claims 1 to 5 and claim 9, wherein the valve element (16 ″, 1) of the valve (15 ″, 15 ″ ″).
6 ″ ′ is provided between the damping throttle (13) and the throttle passage (D ₁ ) in the control pressure conduit (1).
2) acted towards its shut-off position (b) by the pressure prevailing in 2) and prevailing in said bypass conduit (22) by said permanent force (f) and downstream of said blocking throttle passage (D ₂ ). A hydraulic control device characterized in that it is acted toward the through position (a) by the pressure existing in the. 11. The hydraulic control system of claim 9, wherein the bypass conduit (22) is the load retention valve (H).
A hydraulic control device characterized in that the hydraulic control device is connected to the one working conduit (4) including the or directly to the tank (T). 12. The hydraulic control device according to claim 1, wherein the damping throttle (1) is provided in a flow direction toward the load holding valve (H).
A hydraulic control device characterized in that an open check valve (20) for bypassing 3) is provided. 13. The hydraulic control device according to claim 1, wherein the hydraulic control device according to any one of claims 1 to 5 and 12.
The open check valve (20) is the valve (15 ', 1).
5 ″), preferably its valve element (16 ′, 1)
6 ″) is a hydraulic control device characterized by being structurally integrated. 14. The method of claim 1, claims 6 to 9, the serial to any one of claims 11 or claim 12
In the hydraulic control device described above, a pressure accumulator (31) is connected to the control pressure conduit (12) between the throttle passage (D ₁ ) and the damping throttle (13). . 15. The hydraulic control device according to claim 14, wherein a check valve (32) for shutting off in a flow direction opposite to the other working conduit (5) is provided between the throttle passage (D ₁ ) and the other. A hydraulic control device provided in the control pressure conduit (12) between the working passage (5). 16. The hydraulic control device according to at least one of claims 1 to claim 15, wherein the act conduit (4, 5) the control valve (C), a preferably directional control valve inlet On the side, preferably in response to respective demands , a safety shut-off device (A) is connected to a control valve , which is actuable by a working pressure medium via a control means (Z), at least one lift, a load. at least one relief valve (36) is provided, et al is for the moment or load pressure sensor (43) and control means (Z),
The permanent force (f) acting on the valve element (16, 16 ′, 16 ″, 16 ″ ″) and the blocking element (16 ^IV ) causes the opening control pressure of the load holding valve (H), the damping throttle. The setting of (13) and the response characteristics of the safety cutoff device (A) are adjusted so that the load holding valve (H) can move into the load holding position when the safety cutoff device (A) responds. A hydraulic control device characterized by being performed. 17. A hydraulic control system according to claim 16, wherein the sensor (43) is configured as an electrical or electronic sensor and the relief valve (36) is a solenoid valve actuable by the sensor (43). A hydraulic control device characterized by being configured.