Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
  • B65G67/00—Loading or unloading vehicles
  • B65G67/60—Loading or unloading ships
  • B65G67/606—Loading or unloading ships using devices specially adapted for bulk material

Definitions

• the invention relates to a self-creating L-shaped bucket elevator / in particular as a ship unloader, with an endless traction element to which the buckets are fastened, with a bucket elevator foot that has a substantially vertically extending area and one that essentially extends horizontally extending region, has at least one horizontal cylinder for tensioning and / or compensating the tension member and at least one vertical cylinder for holding the bucket elevator foot.
• a steep conveyor of the type mentioned, in particular for ship unloading, is described in EP 0 236 845 AI.
• This steep conveyor has an upper part rotatable about a vertical axis, to the lower end of which a pivotable part is articulated.
• Both strands of the bucket elevator are supported in the area of the articulation on the swing-out side by guides and guided at the lower end via a deflection roller so that work can be carried out in what is known as deep cutting.
• the swing-out part has at its lower end an articulated foot part which projects in the swing-out direction and is connected to the lower part in such a way that it can be held or adjusted horizontally in each swing-out position.
• the swing-out part is formed in particular from two arms forming a parallelogram of the joint, which is acted upon by a hydraulic cylinder connected to the upper part.
• a tensioning device which, for example, also consists of hydraulic cylinders and which can be actuated by a control device, is used to tension the tension member.
• the tension of the tension member is measured and adjusted in the context of a control loop. This results in delays with the risk that damage to the bucket elevator can occur.
• DE 41 00 852 AI describes a ship unloader with an essentially vertically extending region which can be displaced on a jib and which cooperates at its lower end with an essentially horizontally extending region.
• the chains of the bucket elevator are guided in the vertical and horizontal area via deflection elements.
• Lifting devices are provided in the vertical area to raise the horizontal area relative to the vertical area, the changes in chain lengths being compensated for by compensating devices in the horizontal area.
• certain sensors are used, in the form of distance detectors, pressure gauges, strain gauges, etc., which trigger actuation of the corresponding hydraulic cylinders, for example for tensioning the chains, via controls or control loops.
• This system also has the disadvantage that unavoidable time delays occur between measuring the newly set state and the reaction (readjustment of the chain tension).
• the necessary control is very complex and difficult to implement.
• the invention is based on the object of further developing the steep conveyor in such a way that the movement of the bucket elevator foot is coordinated with the ship movements without great technical effort, without the desired tensioning and digging force being exceeded or undershot.
• This object is achieved by the bucket elevator described in claim 1, which is characterized according to the invention in that the vertical and horizontal cylinders are connected to one another via a pressure line in such a way that, without active control loops, one associated with a lowering of the bucket elevator foot Extending a vertical hydraulic cylinder part causes the horizontal hydraulic cylinder part to be retracted accordingly, and conversely, retracting the vertical hydraulic cylinder part associated with the lifting of the bucket elevator foot causes the horizontal cylinder part to be extended accordingly.
• the invention hereby has the advantage that a passive adaptation takes place without distance and / or pressure measurement and corresponding actuation of an adjusting element. Due to the resulting vertical force, the bucket elevator foot follows a downward movement of the bulk material in the ship, the piston rod of the vertical cylinder extending. The necessary length compensation is achieved by retracting the piston rod of the horizontal cylinder or the cylinder connected to the horizontal area. Conversely, with an upward movement of the ship, the piston rod of the vertical cylinder is pushed in and the piston rod of the horizontal cylinder is extended by the oil displacement associated therewith. The tensile force and the digging force between the bulk material and the bucket foot remain constant during operation. The bucket elevator foot automatically adapts to the movement of the ship, which means that the bucket elevator achieves the optimum conveying capacity.
• the above-mentioned principle for coordinating the movement sequences between two independent systems and keeping the force acting between the systems in question constant can be averted for any system, provided that the mass of the system to be controlled is compared with the mass of the system from which the system is to be controlled the movement stops, is very small and that the movements of the larger mass occur with little acceleration or deceleration.
• the bucket elevator foot can also automatically adapt to the fluctuation of the ship, it is preferably provided that the vertical area and the horizontal area can be rotated relative to one another about a joint by means of at least one tilt cylinder about the horizontal axis. Preferably, a change in chain length can also be compensated for by changing the inclination of the horizontal area.
• the hydraulic medium which can additionally be pumped into the vertical hydraulic cylinder by means of a switchable pump compensates the bucket elevator weight or the pumpable hydraulic medium effects an additional pressure force on the bucket elevator foot by increasing the pressure.
• the three possible requirements are taken into account, namely that the dead weight of the bucket foot is very large, that is, the application of a tensile force is desired so that the buckets are not unnecessarily stressed or heavy. If the dead weight of the bucket elevator foot is too small, the desired digging pressure must be generated, which can be done using the vertical cylinder piston.
• the pump can also be designed so that it can be switched on and off depending on the pressure.
• a check valve is installed downstream of the pump.
• the vertical hydraulic cylinder is preferably provided on both sides with end position damping for the piston, which according to a further embodiment of the invention can be mechanical or hydraulic.
• a mechanical end position damping consists, for example, of plate springs arranged at the ends of the cylinders, which can be arranged both inside and outside the cylinder.
• Respective pressure accumulators in the pressure lines are connected to the cavities of the vertical cylinder, which are separated by the piston, or feed them, whereby an excellent pressure stabilization can be achieved.
• a further pressure stabilization results from pressure limiting valves, in particular to keep the tensioning element tension force or the digging force of the cup constant. These pressure relief valves block, for example, when the desired pressure falls below or exceeds a predeterminable value, for example 5%.
• the vertical hydraulic cylinder has a sensor for detecting a predeterminable maximum stop force and for triggering a stroke of the entire bucket elevator. When the maximum impact force is reached, the entire bucket elevator is raised to relieve the foot.
• the present invention also provides a simpler solution for the operating phase of the "cleaning up” by switching from normal operation to "cleaning up” operation it is provided for which purpose a further or additional pressure limiting valve with other characteristic values is used alternatively or in the sense of a parallel connection.
• additional vertical and horizontal hydraulic cylinders for changing the radius of the bucket elevator foot are parallel to the hydraulic cylinders provided for holding the bucket elevator foot on the bulk material and for tensioning and / or balancing the tension member provided.
• FIG. 6 is a partial view of the hydraulic system of FIG. 3 with "cleaning up" switching
• FIG. 9 shows a schematic diagram to illustrate the change in loading.
• Fig. 12 to 14 each schematic circuit diagrams of the hydraulic
• the bucket elevator shown in FIGS. 1 and 2 has a trunk 10 with a carriageway and a bucket foot with a vertical area 70 and a horizontal area 11.
• the buckets 12 are moved in the horizontal area 11, in the vertical area 70 and out in the trunk 10.
• Chain wheels 14 are provided as deflections in the horizontal area 11 and in the vertical area 70.
• two vertical hydraulic cylinders 15 and 16 are provided, which are supported on the one hand on a support 17 of the vertical region 70 and on the other hand supports 18 and 19 of the trunk 10.
• Hydraulic cylinders 20 and 21 arranged in the horizontal region 11 serve to adjust the chain length and to keep the tension constant.
• the hydraulic circuit is shown in FIGS. 3 to 5.
• FIGS. 10 and 11 in which the same parts as in the embodiment according to FIGS. 1 and 2 are provided with the same reference symbols, additionally has articulated tilt cylinders 71 and 72 between the supports 18 and 19 and the horizontal region 11, respectively which enable rotation of the horizontal region 11 about the joint 73 relative to the vertical region 70.
• the bucket elevator foot has a high weight.
• a tensile force is exerted on the bucket elevator foot, ie the pressure Pi in the lower part of the vertical cylinder 15 must be greater than the pressure p ⁇ of the upper space of the cylinder acting here twice.
• a pump 23 is required, which applies the appropriate pressure. This pump is controlled in such a way that it only switches on when the outlet pressure has dropped to a predeterminable value of, for example, 0.95 p ⁇ and switches off when, for example, the pressure reaches the predetermined value p ⁇ .
• the check valve 24 at the pump outlet ensures that the pressure cannot drop when the pump is switched off.
• Pressure limiting valves 25, 33 and 34 protect against excess pressure or a drop in pressure p 0 and / or p ⁇ .
• the cylinders 15 and 20 are each connected to one another on the piston side via a line 26. This ensures that the shortening of the chain strands in the vertical part (when retracting the vertical cylinder 15) is compensated for by a corresponding extension of the strands in the horizontal region 11.
• the pressure accumulators 27 and 28 ensure almost constant oil pressures.
• the arrow 29 indicates that the foot cannot be overstressed even after the compensation path that can be walked on by the piston 15.
• the hoist carrying the bucket elevator receives a signal and moves the bucket elevator upwards to relieve the foot.
• a limit switch can also perform the same function.
• Fig. 4 shows an alternative hydraulic circuit in the event that the dead weight of the foot is just or almost as large as necessary to apply the required digging force.
• the pressure p 0 in the upper region of the cylinder 15 must be greater than the pressure pi.
• the pump 23 is located on the piston side of the cylinder for generating the pressure PQ.
• the valves 32 and 31 limit the line pressure as indicated. The same applies to the parts bearing the same reference numerals as in FIG. 3 as explained for FIG. 3.
• the pressure is determined po practically by the tensioning force F S p in the chains
• the circuit according to FIG. 5 is suitable to take into account an excessively small dead weight of the bucket elevator foot, which not sufficient to create sufficient digging power.
• an additional pressure force is to be generated by the vertical hydraulic cylinder 15 in order to achieve the necessary digging force together with the (too low) own weight of the foot.
• This pressure force is generated by the pressure p ⁇ from the pump 23 on the piston side of the cylinder 15.
• the tension force of the chain results from the difference between the hydraulic forces PoAn and p 2 A ⁇ acting on the two sides of the piston of the cylinder 20, where A Q , AI denote the respective piston surfaces.
• the valves 32, 31 and 35, 36 ensure that the pressures pi and P2 only fluctuate by 5% up and down by the value p ⁇ and P2, respectively.
• the pressure accumulators 37 to 39 also serve to stabilize the pressures pg, Pi and p.
• the circuits described in FIGS. 3 to 5 are suitable for normal operation.
• FIG. 6 shows a changeover in question by means of a directional valve 40, the additional pressure relief valve 48 protecting the hydraulic system against an impermissible pressure during "cleaning up" operation.
• valves 31 and 32 in FIGS. 4 and 5 can be replaced by a partial circuit according to FIG. 7 by switching the valves 49 and 50 to valves 51 and 52, care being taken in each case that the conditions gung Po> Pi is not violated by the changed setting of p ⁇ ⁇ .
• the bucket elevator foot, the horizontal region 11 can be changed in length by extending the hydraulic cylinders 42 and 43.
• two vertical cylinders 44 and 45 are therefore necessary, which are arranged on both sides of the vertical cylinder 15.
• the piston spaces of the additional horizontal cylinders 42 and 43 are connected to the piston spaces of the additional vertical cylinders 44 and 45 by lines 53 and 54, respectively.
• the advantages of the device according to the invention lie in the passive adaptation of the bucket elevator foot to the movement of the ship during operation with a very large compensation path.
• the digging force can be kept practically constant during the movement compensation, as a result of which the conveying capacity of the cups is optimized.
• the sensitive tension adjustment in the chains can be used to use lighter chains.
• the hydraulic system can be varied without great effort when using bucket elevator feet of different weights by combining the hydraulic circuits according to FIGS. 3, 4 and 5 and in each case setting one of the states via a changeover switch.
• a switchover between the trench from the full bulk material and the "cleaning up" operation is readily possible.
• the front loaders previously used can be saved for the purpose of material collection.
• the circuit according to FIG. 12 essentially corresponds to the circuit according to FIG. 3. However, since inclination cylinders 71, 72 (with pressure P 3 ) must also be applied (see FIGS. 10, 11), a further pressure accumulator 75 is provided.
• the cylinder 71 works similarly to the cylinder 15, with one difference, among other things, that a change in chain length when the horizontal region 11 is rotated about the joint 73 is relatively small, so that it is compensated for by the pressure accumulator.
• valves 76, 74 are additionally provided to limit the fluctuation in the pressure P 3 by a maximum of 5%. The same applies accordingly to the circuits according to FIGS. 13 and 14, in which the same parts with the same reference numerals as used for FIGS. 4 and 5 are used.
• the circuits according to FIGS. 15, 16 and 17 represent embodiments for the so-called "cleaning up" operation.
• the pressures p 1 and 3 must be increased, which is achieved by pressure relief valves 48, 78 and 80 is possible.
• 15 in the circuit according to FIG a switchover by means of three three-way valves 40, 77 and 79 is provided, all three additional pressure limiting valves protecting the higher pressures pi and P3 of the hydraulic system from excess pressure.
• valves 31, 32 and 74, 76 in the circuits according to FIGS. 16 and 17 can be replaced by switching the valves 49, 50 and 77, 79 to valves 51, 52 and 78, 80, in each case in compliance the conditions Po> P ⁇ in Fig. 16 and Po ⁇ P ⁇ in Fig. 17th

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• Engineering & Computer Science (AREA)
• Ocean & Marine Engineering (AREA)
• Aviation & Aerospace Engineering (AREA)
• Mechanical Engineering (AREA)
• Ship Loading And Unloading (AREA)

Applications Claiming Priority (5)

Publications (1)

Family

ID=25933036

Family Applications (1)

Country Status (9)

Families Citing this family (7)

Family Cites Families (7)

• 1995
  • 1995-01-07 JP JP7518817A patent/JPH08507999A/ja active Pending
  • 1995-01-07 AU AU13861/95A patent/AU682088B2/en not_active Ceased
  • 1995-01-07 BR BR9505822A patent/BR9505822A/pt not_active IP Right Cessation
  • 1995-01-07 US US08/525,642 patent/US5651447A/en not_active Expired - Fee Related
  • 1995-01-07 EP EP95905126A patent/EP0688297A1/de not_active Withdrawn
  • 1995-01-07 CN CN95190030A patent/CN1044797C/zh not_active Expired - Lifetime
  • 1995-01-07 WO PCT/EP1995/000051 patent/WO1995019313A1/de not_active Application Discontinuation
  • 1995-08-31 NO NO953407A patent/NO953407D0/no unknown
  • 1995-09-13 FI FI954303A patent/FI954303A/fi unknown

Non-Patent Citations (1)

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