EP2551232A1 - Crane control system - Google Patents

Abstract

The system (10) has two pumping units (13', 13'') and two split control blocks (15', 15'') to supply a hydraulic load of a crane with a hydraulic medium. One of the pumping units is connected to one of the split control blocks and driven by hydraulic pressure. The other pumping unit is connected to the other split control block and driven by another hydraulic pressure. A valve unit (50) is arranged between the split control blocks. The split control blocks are hydraulically connected to and disconnected from the valve unit.

Description

The present invention relates to a crane control system for the control and / or hydraulic supply of hydraulic consumers of a crane and a crane with at least one crane control system.

Crane control systems with so-called load-sensing are known in cranes with hydraulically actuated crane actuators. Various crane movements can be driven independently of each other. The controller determines the pressure required by each crane actuator and determines the maximum pressure required. The controller then automatically adjusts the hydraulic pump to the pressure determined.

This is a safe and robust procedure. Proportional slides then supply the respective crane actuators with the hydraulic medium.

In the load sensing system according to the prior art (see also FIG. 2 ), most consumers are interconnected hydraulically in the open hydraulic circuit. Only the slewing gear is disconnected, since this is to be operated also in the mode "closed hydraulic circuit".

Now each crane actuator needs an individual hydraulic pressure and an individual hydraulic quantity.

Typically, the rocker cylinder requires a high hydraulic pressure, a winch often requires a large amount of hydraulic oil.

If the luffing gear needs 330 bar and 100 l / min and the winch requires z. B. a pressure of 60 bar and a hydraulic oil amount of 200 l / min, then the hydraulic pressure in the responsible for the winch Proportionalschieber must be reduced. The difference of 300 bar - 60 bar = 240 bar is then reduced in the proportional valve and converted into heat. The converted into heat power in this case is about 80 kW. The following formula can be applied in practice: $$P\left[\mathit{kW}\right]=\frac{\mathit{pressure\; difference}\left[\mathit{bar}\right]*\mathit{flow}\left[l/\min \right]}{600}$$

It can be seen that the larger the pressure difference and the larger the volume flow, the greater the "losses" become.

It is therefore an object of the present invention to develop a crane control system of the type mentioned in an advantageous manner.

This object is achieved by a crane control system with the features of claim 1. Thereafter, it is provided that a crane control system for controlling and / or hydraulic supply hydraulic consumers of a crane with at least a first pump means and at least one second pump means, at least a first sub-control block and is provided at least a second sub-control block, by means of which in each case at least one hydraulic consumer of the crane can be supplied with hydraulic medium, wherein the first pumping means is connected to the first sub-control block and is operable with a first hydraulic pressure and wherein the second pumping means is connected to the second sub-control block and can be operated with a second hydraulic pressure.

This results in particular the advantage that first hydraulic consumers of a crane, which must be supplied with a small or comparatively lower operating pressure with hydraulic medium can be supplied without corresponding reduction of the operating pressure of the hydraulic medium, for example by the first pump means and the first sub-control block. Furthermore, advantageously second hydraulic consumers, which have to be supplied with a high or comparatively higher operating pressure with hydraulic medium, can be supplied directly with a corresponding operating pressure of the hydraulic medium, for example through the second pumping means and the second sub-control block.

It can be provided that between the first sub-control block and the second sub-control block at least one valve means is arranged or provided, by means of which the first sub-control block and the second sub-control block are hydraulically connectable and / or separable. By opening advantageously a hydraulic short circuit can be brought about, so that, for example, faster crane movements are possible, for example when needed. In this case, the loss of power mentioned in the introduction as a result of the necessary pressure reduction are deliberately accepted.

It is also conceivable that at least one switch means is provided, by means of which the valve means can be actuated. By means of the switch means, which may be a switch or a so-called "eco-switch", the crane operator can deliberately switch to the energy-saving crane control with mutually separated by the valve means Umsteuerblöcken, ie not hydraulically shorted Umsteuerblöcken. The division into the at least two Umsteuerblöcke can thus always then be activated by the crane operator, if the current work situation allows energy to be saved. In this case, the crane operator actively activates the "eco-switch" to activate the energy-saving function. If the crane operator already knows that he often requires high volume flows of the hydraulic medium due to the necessary operation of hydraulic consumers of the crane with high operating pressure of the hydraulic medium in the upcoming lifting work with the crane, the eco-switch is not activated or switched accordingly or deactivated.

In addition, it can be provided that further at least a third pump means and at least a third sub-control block is provided, by means of which at least one hydraulic consumer of the crane can be supplied with hydraulic medium, wherein the third pump means is connected to the third sub-control block and can be operated with a third hydraulic pressure ,

It is also possible that between the third sub-control block and the first sub-control block and / or the second sub-control block at least a second valve means is arranged or provided, by means of which the third sub-control block with the first sub-control block and / or the second sub-control block hydraulically connectable and / or separable is.

It is also conceivable that at least one further switch means is provided, by means of which the second valve means is actuated and / or by means of the switch means, by means of which the valve means is actuated, and the second valve means is actuated.

It can be provided that at least one crane control element, in particular a crane control is provided, by means of which the at least one first hydraulic pressure and / or the at least one second hydraulic pressure is adjustable, wherein it is further preferably provided that the third hydraulic pressure can be adjusted by means of the crane control element.

Moreover, it is possible that by means of the crane control element of the first or the second hydraulic pressure can be equalized, wherein preferably the respective lower hydraulic pressure is equalized to the higher hydraulic pressure and thus increased.

In addition, it can be provided that the respective at least one hydraulic consumer of the crane is a crane actuator, wherein in particular the crane actuator is a slewing gear, a rocking cylinder, a winch, a telescopic drive and / or a caterpillar drive.

Hydraulic consumers, ie crane actuators, can be in particular luffing cylinders, telescopic cylinders, caterpillar drives, auxiliary consumers (eg rockers or telescoping of the cabin arm, ballast cylinders) and / or winches for hoisting gear or luffing gear.

Furthermore, the present invention relates to a crane with the features of claim 10. Thereafter, it is provided that a crane with at least one crane control system according to one of claims 1 to 9. The crane may be, for example, a mobile crane.

Further details and advantages of the invention will now be described with reference to an embodiment shown in the drawing.

Fig. 1:

eine schematische Darstellung eines Mobilkrans in der Seitenansicht;

Fig. 2:

eine schematische Ansicht eines Kransteuerungssystems gemäß dem Stand der Technik;

Fig. 3:

eine schematische Darstellung des erfindungsgemäßen Kransteuerungssystems;

Fig. 4:

eine weitere schematische Darstellung des erfindungsgemäßen Kransteuerungssystems; und

Fig. 5:

eine weitere schematische Darstellung des erfindungsgemäßen Kransteuerungssystems.

Show it

Fig. 1:

a schematic representation of a mobile crane in the side view;

Fig. 2:

a schematic view of a crane control system according to the prior art;

3:

a schematic representation of the crane control system according to the invention;

4:

a further schematic representation of the crane control system according to the invention; and

Fig. 5:

a further schematic representation of the crane control system according to the invention.

Fig. 1 shows a schematic side view of a crane with a crane control system according to the invention. Such a crane 1 has a superstructure 3 and an undercarriage 2 with a plurality of crane actuators, such as a slewing gear 4, luffing cylinder 5, winches 6 or a lifting mechanism 6 and a telescopic drive 7.

Furthermore, various encoders 8 and input and output units 9, here control transmitter with touch displays 9 and a so-called LICCON screen 9 with display and input means, and a crane control 10 are provided. Whether it is the crane 8 is a single or twin-engine crane is irrelevant.

For example, if it is a single-engine crane, then the energy from the undercarriage 2 through the rotary feedthrough 11 to the superstructure 3 is performed. In a twin-engine crane eliminates the rotary feedthrough 11th

Furthermore, the crane has an internal combustion engine 12, namely a diesel engine 12. This internal combustion engine 12 drives directly or indirectly various pumps 13. In principle, at least one pump 13 is provided. The pumps 13 of the crane actuators for the load-sensing system are in an open hydraulic circuit.

The bus system 14 for data and energy transfer is by means of a line with hatching in the FIG. 2 shown. Further, a control block 15 is provided, which supplies the Kranaktuatoren with hydraulic medium. Volume flow Q and hydraulic pressure p for each crane actuator is individually set in the control block via the controlled proportional shifters 16. So there is a pressure compensator available.

FIG. 2 shows a schematic view of a crane control system according to the prior art. I'm in the FIG. 2 the system according to the invention can not be implemented, since only one pump 13 for the load-sensing system are present, as already explained above. The pump 13 is a variable displacement pump 13 and may be a gear pump coupled to and driven by the diesel engine 12.

But now there is a crane before 1, which has two or more pumps 13 for the load-sensing system due to its performance, then in the prior art, the system of the FIG. 2 used and there arises the above-described problem with the "power loss".

FIG. 3 now shows schematically the crane control system according to the invention, which can also be referred to as a load-sensing system, namely in particular as a "combined load-sensing pump control".

There are at least 2 pumps 13 'and 13 "in addition to the pump 13 for the supply of the crane actuators in addition to the pump 13. The previously described pressure compensator is present, but now at least one valve 50 is installed in the control block which covers the entire control block 15 in at least two sub-control blocks 15 'and 15 "can divide.

FIG. 4 shows the solution with 3 pumps 13 'and 13 "and 13"' and with three independent load-sensing systems. It is self-explanatory that, after short-circuiting the various previously independent load-sensing systems, the systems are no longer independent but form a common load-sensing system.

In the case according to FIG. 4 can be mentioned as an added advantage that most and the most commonly performed crane movements independently be executed. Even if the effects of the operation of a proportional slide 16 are low, they are nevertheless present and can introduce each other vibrations.

In principle, at least 2 independent load-sensing systems are created. If the crane actuators are now assigned to the two load-sensing systems such that crane actuators, which typically require a high hydraulic pressure p and, on the other hand, crane actuators, which typically require a high volume flow Q, are interconnected, then a relevant reduction in the power to be converted into heat can be achieved (see also the above formula).

The division into the at least two sub-control blocks 15 'and 15 "can then always be run in order to save energy, and it could also be possible for the crane operator to actively actuate an" eco-switch "in order to activate or deactivate the energy-saving function according to the invention It can then be efficient if the crane operator already knows that he often needs the high volume flow Q in the upcoming lifting work, in which case he does not actuate the eco-switch.

Also, different pumps could be used, whose characteristics are adapted to the specific requirements of the associated Kranaktuatoren. However, if the crane controller 10 determines that a consumer is requesting a higher volume flow Q than the associated pump 13 'or 13 "is able to provide, then the crane controller 10 will first cause the pump, having the lower hydraulic pressure p, to increase its hydraulic pressure Thus, both pumps 13 'and 13 "can jointly provide the requested volume flow Q. Although this is purchased at a higher" power dissipation ", it ensures faster crane movements and Thus, again for saving in other areas.

The valve 50 is a valve that operates either fully open or fully closed. Thus arise in the valve 50 no losses. However, since the required hydraulic pressure p is set beforehand, the opening or closing of the valve 50 is not appreciable or otherwise detrimental to the performance of the crane 1.

Since the turning of the upper carriage 3 is approached anyway by a separate pump 13, so 3 movements can be performed simultaneously and without losses. Experience has shown that the most frequently performed movements of the crane actuators are turning, lifting and lowering the load and rocking.

It should also be mentioned that in this solution, the internal combustion engine 12 can not be designed to be switched off, since, for example, the air conditioning compressor has to continue to be operated. The fuel savings result solely from the "combined load-sensing pump control".

The encoders 8 may be different sensors at various locations, e.g. Pressure sensors, angle encoders, etc.

FIG. 5 shows a solution in which the maximum pressure is measured by the encoders 8 in each of the at least 2 independent load-sensing systems. Now, if the valve 50 to close, then causes the crane control 10 as described above, the at least two pumps 13 to set the higher of both provided hydraulic pressure p. The achievement of the hydraulic pressure p is again detected by encoders 8 and reported back to the crane control 10.

Claims (10)

Crane control system for controlling and / or hydraulically supplying hydraulic consumers of a crane with at least one first pumping means (13 ') and at least one second pumping means (13 "), at least one first sub-control block (15') and at least one second sub-control block (15"), by means of which in each case at least one hydraulic consumer of the crane can be supplied with hydraulic medium, wherein the first pumping means (13 ') is connected to the first sub-control block (15') and is operable with a first hydraulic pressure and wherein the second pumping means (13 ") is connected to the first second sub-control block (15 ") is connected and operable with a second hydraulic pressure. Crane control system according to claim 1, characterized in that between the first sub-control block (15 ') and the second sub-control block (15 ") at least one valve means (50) is arranged or provided by means of which the first sub-control block (15 ') and the second sub-control block (15 ") are hydraulically connectable and / or separable. Crane control system according to claim 2, characterized in that at least one switch means is provided, by means of which the valve means (50) is actuated. Crane control system according to one of the preceding claims, characterized in that further at least one third pump means (13 "') and at least one third sub-control block (15"') is provided, by means of which at least one hydraulic consumer of the crane can be supplied with hydraulic medium, wherein the third Pump means (13 "') is connected to the third sub-control block (15"') and is operable with a third hydraulic pressure. Crane control system according to claim 4, characterized in that between the third sub-control block (15 "') and the first sub-control block (15') and / or the second sub-control block (15") at least one second valve means (50 ') is arranged or provided, by means of which the third sub-control block (15 ') is hydraulically connectable and / or separable with the first sub-control block (15') and / or the second sub-control block (15 "). Crane control system according to claim 5, characterized in that at least one further switch means is provided, by means of which the second valve means (50 ') is actuated and / or by means of the switch means by means of which the valve means (50) is operable, the second valve means ( 50 ') is actuated. Crane control system according to one of the preceding claims, characterized in that at least one crane control element (10), in particular a crane control (10) is provided, by means of which at least one first hydraulic pressure and / or the at least one second hydraulic pressure is adjustable, wherein it is further preferably provided that by means of the crane control element (10) of the third hydraulic pressure is adjustable. Crane control system according to claim 7, characterized in that by means of the crane control element (10) of the first or the second hydraulic pressure can be equalized, wherein preferably the respective lower hydraulic pressure is equalized to the higher hydraulic pressure and thus increased. Crane control system according to one of the preceding claims, characterized in that the respective at least one hydraulic consumer of the crane is a crane actuator, wherein in particular the crane actuator comprises a slewing gear (4), a rocking cylinder (5), a winch (6), a telescopic drive (7). and / or a caterpillar drive. Crane with at least one crane control system according to one of the preceding claims.

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