A kind of pretension of marine crane boom is shelved method and device
Technical field
The present invention relates to a kind of deck crane, the pretension that particularly relates to a kind of marine crane boom is shelved method and device, belongs to the hoisting crane technical field.
Background technology
Existing deck crane is when off working state, and arm fell and was held on the support that is fixed on hull, and the arm of this moment is two point-supported angular member, bears moment of flexure that self gravitation produces.Different from the land hoisting crane is, marine crane boom is except the D/W of bearing the arm self gravitation, also need to bear hull jolts and rocks generation in the ship's navigation impact load and alternate load, this moment, impact failure and endurance failure occured in arm easily, particularly marine hurricane is so that each second, 55 meters wind speed caused that hull is jumbo to jolt, arm often needs to bear when being equivalent to mode of operation even higher load, position little for hull, support is in the overlength arm in arm stage casing, the load that bears even can exceed several times of workload.Produce easily the technical matters of impact failure and endurance failure for marine crane boom because bearing hull impact load and the alternate load that rocks generation that jolt, existing technological means is still and adopts traditional enhancing boom structure, improve the mode of its shock resistance and fatigue resistance, yet, this mode can increase the complete machine weight of arm and even hoisting crane, thereby increase the load of hoisting crane and boats and ships, reduce the work efficiency of hoisting crane and the conveying efficiency of boats and ships, particularly be difficult to adapt to the needs to the ocean engineering ships such as jack-up platform of the restricted requirement of hoisting crane weight.If the arm of shelving is adopted the fixed form that is bundled on support or the boats and ships, then there are the problems such as reinforcement process is complicated, consolidation time is long, labour intensity is large, be difficult to tackle marine changeable climate, poor stability does not possess feasibility.
Chinese patent notification number: CN86203711, the day for announcing: on February 11st, 1987, a kind of tower crane with cable is disclosed, two load-bearing hawsers that are connected between tower arm end and the body of the tower top are arranged, and this hawser is suspending the amplitude variation trolley that moves back and forth along hawser in midair, after the weight lifting, lift heavy all acts on the load-bearing hawser, make the tower arm basically only bear axial force, when having overcome lift heavy and directly acting on the tower arm chord member, the tower arm need to bear the shortcoming of very large moment of flexure.Chinese patent notification number: CN2467487Y, the day for announcing: December 26 calendar year 2001, the utility model name is called " draw-bar pulley balancing apparatus for tower crane ", the connecting device of pulling force between a kind of balancing pull rod is disclosed, the top of tower crane is equipped with pulley, is wound with balanced drag-line on the pulley, and balanced drag-line connects the pull bar of hoisting crane, pulling force between balanced drag-line energy balance crane pull bar, thereby stability and the work efficiency of raising hoisting crane.The arm of hoisting crane still is subject to the constraint of load-bearing hawser, pull bar or balanced drag-line in the aforementioned prior art under light condition, the operating mode that arm is shelved and jolted without constraint can not appear, more do not solve impact failure that impact load under this operating mode and alternate load cause arm and the technical matters of endurance failure, load-bearing hawser, balanced drag-line, the isostructural purpose of pulley that arranges also is intended to improve the stressing conditions of arm when in running order, rather than solves arm and be in stressed disadvantageous technical matters when shelving state.
Summary of the invention
First purpose of the present invention is overcome that the method for shelving of existing marine crane boom exists impacts easily and destroy and defective and the deficiency of endurance failure because arm bears the jolt impact load that rocks generation and alternate load of hull, provide a kind of pretension of marine crane boom to shelve method, can effectively reduce that arm rocks impact failure that the impact load that bears and alternate load produce and endurance failure because hull jolts and to the damage of hull, can significantly reduce simultaneously the moment of flexure that crane arm produces in the deadweight of shelving under the state, improve the stressing conditions of arm, alleviate the deadweight of boom structure, prolong arm, the service life of hoisting crane and even boats and ships.
Second purpose of the present invention is to overcome conduct oneself with dignity when the shelving state moment of flexure that produces and be out of shape larger of arm that the shelving unit of existing marine crane boom exists, bearing hull jolts the impact load that rocks generation and alternate load and impacts easily and destroy and defective and the deficiency of endurance failure, a kind of pretension shelving unit of marine crane boom is provided, make arm when shelving state, bear pulling force upwards, thereby significantly reduce moment of flexure and distortion that the arm deadweight produces, significantly alleviate simultaneously alternate load and impact load and consequent endurance failure and the impact failure that acts on arm, and simple in structure, easy to operate, safety is good.
The present invention realizes that the technical scheme that first purpose adopts is: a kind of pretension of marine crane boom is shelved method, described deck crane comprises by arm, the top pulleys group, the winch of belt brake, the luffing mechanism that arm head assembly pulley and variable-amplitude steel wire rope form and the support that is fixed in hull, described top pulleys group is arranged at the top of hoisting crane, the winch of described belt brake and arm are arranged at respectively the both sides of deck crane, described arm head assembly pulley is arranged at the end of arm, there is variable-amplitude steel wire rope to be connected with arm head assembly pulley through the top pulleys group on the winch, it is characterized in that may further comprise the steps:
A. forward starts winch, loosens variable-amplitude steel wire rope, arm is moved downward and is shelved on the support;
B. oppositely start winch, the tension variable-amplitude steel wire rope makes arm to the pressure of the support pressure to support when loosening that arm is held on the support behind the variable-amplitude steel wire rope, checks and closes winch and get final product.
A kind of pretension of marine crane boom is shelved method, before the described steps A, the middle part pulley is set in the stage casing of arm first, and the variable-amplitude steel wire rope on the winch is connected with the middle part pulley with arm head assembly pulley through the top pulleys group.
A kind of pretension of marine crane boom is shelved method, and among the described step B, behind the tension variable-amplitude steel wire rope, it is to loosen when arm is held on the support behind the variable-amplitude steel wire rope 1/4~1/10 of the pressure of support that arm acts on pressure on the support.
A kind of pretension of marine crane boom is shelved method, in the described steps A, also comprise the default value of thrust of setting first variable-amplitude steel wire rope tension arm, oppositely start winch tension variable-amplitude steel wire rope among the described step B after be equal to or greater than default value of thrust, check and close winch.
A kind of pretension of marine crane boom is shelved method, and is further comprising the steps of after the described step B:
C. when the prefastening force of variable-amplitude steel wire rope is lower than default value of thrust, pine is stopped and oppositely starts winch, and winch is checked and closed to the retighten variable-amplitude steel wire rope after be equal to or greater than default value of thrust again.
The present invention realizes that the technical scheme that second purpose adopts is: a kind of pretension shelving unit of marine crane boom, comprise by arm, the top pulleys group, the winch of belt brake, the luffing mechanism that arm head assembly pulley and variable-amplitude steel wire rope form and the support that is fixed on hull, described top pulleys group is arranged on the top of deck crane, the winch of described belt brake and arm are arranged at respectively the both sides of hoisting crane, described arm head assembly pulley is arranged on the end of arm, in the described luffing mechanism, also comprise the middle part pulley that is arranged at the arm stage casing, the variable-amplitude steel wire rope on the described winch is connected with the middle part pulley with arm head assembly pulley through the top pulleys group.
A kind of pretension shelving unit of marine crane boom, described arm head assembly pulley comprises the first head pulley, described top pulleys group comprises the first top pulleys, the second top pulleys and the 3rd top pulleys, one end of described variable-amplitude steel wire rope is fastened on winch, the other end is walked around the first top pulleys, the first head pulley, the second top pulleys, middle part pulley and the 3rd top pulleys successively, is wrapped on the winch in the same way again.
A kind of pretension shelving unit of marine crane boom, described arm head assembly pulley comprises the first head pulley and the second head pulley, described top pulleys group comprises the first top pulleys, the second top pulleys, the 3rd top pulleys and the 4th top pulleys, one end of described variable-amplitude steel wire rope is fastened on winch, the other end is walked around the first top pulleys, the first head pulley, the second top pulleys, middle part pulley, the 3rd top pulleys, the second head pulley and the 4th top pulleys successively, is wrapped on the winch in the same way again.
Compared with prior art, beneficial effect of the present invention is:
1. by variable-amplitude steel wire rope arm is applied a certain size predetermincd tension, can obviously reduce support to the bearing force of arm, jolt when rocking at ship's navigation, hull, this bearing force changes, reduce this bearing force and can reduce alternate load and the impact load that support acts on arm, avoid arm to produce endurance failure and impact failure, prolong the service life of arm.
2. variable-amplitude steel wire rope has formed the new fulcrum of arm to the pulling force point of arm, has reduced the span as the arm of angular member, thereby has reduced the moment of flexure peak value of arm, and the arm integral load is alleviated and distributing equilibrium greatly, has improved the stressing conditions of arm.
3. variable-amplitude steel wire rope is upwards strained arm, limited the upper and lower displacement of arm in fluctuating is rocked, and repeatedly bears the endurance failure that alternate load up and down causes thereby reduced arm.
4, the Design cooling load of arm significantly reduces, the cross-sectional area of its structure is corresponding reducing also, thereby the deadweight of arm and even the deadweight of deck crane are also reduced, particularly adapt to the needs to the ocean engineering ships such as jack-up platform of the restricted requirement of hoisting crane weight.
5. the amount of force of variable-amplitude steel wire rope tractive arm can or be loosened variable-amplitude steel wire rope and regulate by the tension of rotation winch, and its apparatus structure is simple, with low cost, easy to use.
Description of drawings
Fig. 1 is the structural representation of marine crane boom pretension shelving unit of the present invention.
Fig. 2 is that marine crane boom pretension of the present invention is shelved the first structural representation that method is used.
Fig. 3 is that marine crane boom pretension of the present invention is shelved the second structural representation of method application and the first structural representation of pretension shelving unit.
Fig. 4 is that marine crane boom pretension of the present invention is shelved the third structural representation of method application and the second structural representation of pretension shelving unit.
Among the figure: arm head assembly pulley 1, the first head pulley 11, the second head pulley 12, variable-amplitude steel wire rope 2, middle part pulley 3, top pulleys group 4, the first top pulleys 41, the second top pulleys 42, the three top pulleys 43, the 4th top pulleys 44, the winch 5 of belt brake, support 6, arm 7, hull 8.
The specific embodiment
The present invention is described in further detail below in conjunction with the drawings and specific embodiments.
Referring to Fig. 2, marine crane boom pretension of the present invention is shelved the first structural representation that method is used, the top of deck crane is provided with top pulleys group 4, the both sides of deck crane are respectively arranged with winch 5 and the arm 7 of belt brake, the end of arm 7 is provided with arm head assembly pulley 1, there is variable-amplitude steel wire rope 2 to be connected with arm head assembly pulley 1 through top pulleys group 4 on the winch 5, wherein, top pulleys group 4 comprises the first top pulleys 41 and the second top pulleys 42, arm head assembly pulley 1 comprises the first head pulley 11, variable-amplitude steel wire rope 2 one ends are fastened on winch 5, one end is walked around the first top pulleys 41 successively, the first head pulley 11, the second top pulleys 42 is wrapped on the winch 5 more in the same way.
The pretension method of shelving of marine crane boom may further comprise the steps:
A. forward starts winch 5, loosens variable-amplitude steel wire rope 2, makes arm 7 move downward and be shelved on the support 6;
B. oppositely start winch 5, tension variable-amplitude steel wire rope 2, the pressure that makes 7 pairs of supports 6 of arm to the pressure of support 6, are checked and are closed winch 5 and get final product when loosening variable-amplitude steel wire rope 2 rear arms 7 and be held on the support 6.
The pretension of marine crane boom provided by the invention is shelved method, can also be before steps A, first in hoisting crane column top and winch 5 phase the same sides leading sheave is set, the variable-amplitude steel wire rope 2 on the winch 5 links to each other with arm head assembly pulley 1 through leading sheave, top pulleys group 4.Leading sheave can be controlled the sense of motion of variable-amplitude steel wire rope 2, makes variable-amplitude steel wire rope 2 keep certain distance with the hoisting crane column all the time, prevents that variable-amplitude steel wire rope 2 on the gos and hoisting crane column from rubbing, and affects the operation of its motion or luffing mechanism.
After implementing arm pretension provided by the invention and shelving method, implement pulling force upwards by 2 pairs of arms of variable-amplitude steel wire rope 7, significantly reduced the bearing force of 6 pairs of arms 7 of support, under ship's navigation, hull jolt the situation of rocking, this bearing force changes, can reduce alternate load and the impact load that support acts on arm so reduce this bearing force, avoid arm to produce endurance failure and impact failure, prolong the service life of arm.On the other hand, the pulling force point of 2 pairs of arms 7 of variable-amplitude steel wire rope has formed the new fulcrum of arm, reduced the span as the arm 7 of angular member, thereby moment of flexure peak value and the maximum defluxion of arm 7 have been reduced, arm 7 integral loads and strain are reduced and distributing equilibrium greatly, improved the stressing conditions of arm 7.In addition, variable-amplitude steel wire rope 2 is upwards strained arm 7, limited arm 7 downward displacement in fluctuating is rocked, and has reduced arm 7 and has repeatedly born the endurance failure that larger up and down alternate load and distortion cause.Marine crane boom pretension provided by the invention is shelved method, ingeniously utilized existing luffing mechanism, make luffing mechanism not only can when deck crane is worked, be used for changing lifting amplitude and scope, the pretension that can also be when deck crane quits work be used for arm be shelved, and the method is simple to operate, effect is remarkable, safe and reliable.
The pretension of marine crane boom provided by the invention is shelved method, the prefastening force of variable-amplitude steel wire rope 2 can be regulated by the rotation of winch 5, rotation tension by winch 5 or unclamp variable-amplitude steel wire rope 2, can increase or reduce the pretension of variable-amplitude steel wire rope 2, the apparatus structure of the prefastening force of this adjusting arm 7 is simple, with low cost, easy to use.
The pretension of marine crane boom provided by the invention is shelved method, before steps A, middle part pulley 3 is set in the stage casing of arm 7 first, and the variable-amplitude steel wire rope 2 on the winch 5 is connected with middle part pulley 3 with arm head assembly pulley 1 through top pulleys group 4.
Referring to Fig. 3, the pretension of marine crane boom provided by the invention is shelved the second structural representation that method is used, wherein, top pulleys group 4 comprises the first top pulleys 41, the second top pulleys 42 and the 3rd top pulleys 43, arm head assembly pulley comprises the first head pulley 11, variable-amplitude steel wire rope 2 one ends are fastened on winch 5, the other end is walked around the first top pulleys 41, the first head pulley 11, the second top pulleys 42, middle part pulley 3, the 3rd top pulleys 43 successively, then is fastened in the same way on winch 5.
Referring to Fig. 4, the pretension of marine crane boom provided by the invention is shelved the third structural representation that method is used, wherein, arm head assembly pulley 1 comprises the first head pulley 11 and the second head pulley 12, top pulleys group 4 comprises the first top pulleys 41, the second top pulleys 42, the 3rd top pulleys 43 and the 4th top pulleys 44, the stage casing of arm 7 also is provided with middle part pulley 3, one end of variable-amplitude steel wire rope 2 is fastened on winch 5, the other end is walked around the first top pulleys 41 successively, the first head pulley 11, the second top pulleys 42, middle part pulley 3, the 3rd top pulleys 43, the second head pulley 12 and the 4th top pulleys 44 are wrapped on the winch 5 more in the same way.
The setting of middle part pulley 3, further increased arm 7 fulcrum, reduced span as the arm 7 of angular member, strengthened the pulling force effect that arm 7 is made progress, the deformation displacement that has limited arm 7, thereby further alleviated arm gravity load, support 6 to the impact load of arm 7 and alternate load impact and the destruction on boom structure.Variable-amplitude steel wire rope 2 is implemented pulling force upwards to arm 7 simultaneously by end pulley 1 and middle part pulley 3, and the adjusting by pulley makes two pulling force synchronous, forms statically determimate structure, make structure stress evenly, good stability.
The pretension of marine crane boom provided by the invention is shelved method, behind the tension variable-amplitude steel wire rope 2, arm 7 acts on the pressure on the support 6, to 1/4~1/10 of the pressure of support 6 when loosening variable-amplitude steel wire rope 2 rear arms 7 and being held on the support 6, impact failure and endurance failure that the bearing force of 6 pairs of arms 7 of support is produced are reduced to minimum, guarantee simultaneously that arm 7 is in stablely to shelve and be unlikely to unsettled.
The pretension of marine crane boom provided by the invention is shelved method, in steps A, also comprise the default pulling force that presets variable-amplitude steel wire rope 2 tension arms 7, oppositely start winch 5 tension variable-amplitude steel wire ropes 2 among the step B when being equal to or greater than default pulling force, can check and close winch 5.The size setting of the default pulling force of variable-amplitude steel wire rope 2 and deadweight, the hull of arm 7 degree of rocking of jolting is relevant, arm 7 deadweights are larger, hull jolts, and the amplitude of rocking is larger, the default pulling force of variable-amplitude steel wire rope 2 should be larger, but prefastening force can not surpass the power that overcomes arm 7 deadweights simultaneously.Before marine crane boom 7 is implemented pretension, the parameters such as the degree of rocking of can jolting according to deadweight, the hull of arm 7 determine that needs variable-amplitude steel wire rope 2 acts on the default pulling force size of arm 7, can make on the one hand more convenient to operate that pretension shelves, can also realize on the other hand the accurate pretension to arm 7, make arm 7 be in best stressing conditions.
The pretension of marine crane boom provided by the invention is shelved method, further comprising the steps of after the step B: C, when the prefastening force of variable-amplitude steel wire rope 2 is lower than default pulling force, pine is stopped and oppositely starts winch 5, winch 5 is checked and closed to tension variable-amplitude steel wire rope 2 after be equal to or greater than default value of thrust.Variable-amplitude steel wire rope 2 is in for a long time tension and may produces loosening, hull repeatedly jolts to rock and also may cause the loosening of variable-amplitude steel wire rope 2 in addition, make the prefastening force value of variable-amplitude steel wire rope 2 be lower than default value of thrust, at this moment can stop and reverse opening winch 5 by pine, retighten variable-amplitude steel wire rope 2 is after be equal to or greater than default value of thrust, check and close winch 5, be in best stressing conditions to guarantee arm.
Referring to Fig. 1, a kind of structural representation of marine crane boom pretension shelving unit, the top of deck crane is provided with top pulleys group 4, the both sides of deck crane are respectively arranged with winch 5 and the arm 7 of belt brake, the end of arm 7 is provided with arm head assembly pulley 1, the middle part is provided with middle part pulley 3, has variable-amplitude steel wire rope 2 to be connected with middle part pulley 3 with arm head assembly pulley 1 through top pulleys group 4 on the winch 5.
The setting of middle part pulley 3, further increased arm 7 fulcrum, reduced span as the arm 7 of angular member, strengthened the pulling force effect that arm 7 is made progress, the deformation displacement that has limited arm 7, thereby further alleviated arm gravity load, support 6 to the impact load of arm 7 and alternate load impact and the destruction on boom structure.Variable-amplitude steel wire rope 2 is implemented pulling force upwards to arm 7 simultaneously by end pulley 1 and middle part pulley 3, and the adjusting by pulley makes two pulling force synchronous, forms statically determimate structure, make structure stress evenly, good stability.On the other hand, when deck crane is worked, the middle part pulley 3 that increases has increased the ran number of the variable-amplitude steel wire rope 2 of tractive arm 7 simultaneously, has reduced by every section pulling force that steel rope bears, the overlength arm that is applicable to conduct oneself with dignity larger and the situation of steel rope undercapacity.
Referring to Fig. 3, the first structural representation of the pretension shelving unit of marine crane boom provided by the invention, wherein, arm head assembly pulley 1 comprises the first head pulley 11, top pulleys group 4 comprises the first top pulleys 41, the second top pulleys 42 and the 3rd top pulleys 43, one end of variable-amplitude steel wire rope 2 is fastened on winch 5, the other end is walked around the first top pulleys 41, the first head pulley 11, the second top pulleys 42, middle part pulley 3 and the 3rd top pulleys 43 successively, is wrapped in the same way on the winch 5 again.
Referring to Fig. 4, the second structural representation of the pretension shelving unit of marine crane boom provided by the invention, wherein, arm head assembly pulley 1 comprises the first head pulley 11 and the second head pulley 12, top pulleys group 4 comprises the first top pulleys 41, the second top pulleys 42, the 3rd top pulleys 43 and the 4th top pulleys 44, one end of variable-amplitude steel wire rope 2 is fastened on winch 5, the other end is walked around the first top pulleys 41 successively, the first head pulley 11, the second top pulleys 42, middle part assembly pulley 3, the 3rd top pulleys 43, the second head pulley 12 and the 4th top pulleys 44 are wrapped on the winch 5 more in the same way.
Arm head assembly pulley 1 is comprised of 2 pulleys, has increased the ran number of variable-amplitude steel wire rope 2 tractive arms 7, has reduced by every section pulling force that steel rope bears, and need to be applicable to tractive conduct oneself with dignity king-sized overlength arm and the situation of steel rope undercapacity.
The above specifies embodiments of the invention by reference to the accompanying drawings, but the present invention is not limited to above-described embodiment, in the ken that those of ordinary skills possess, can also make a variety of changes not breaking away under the aim prerequisite of the present invention.