A method for installing a gantry crane

Abstract

The present invention relates to the technical field of lifting machinery, and in particular to a method for installing a gantry crane. The method for installing a gantry crane comprises the following steps: setting a connecting section at the installation position of a rigid leg under a main beam, and making the inner side height of the connecting section lower than a first set value of the outer side height, and rotating and connecting the outer side of the rigid leg to the outer side of the connecting section; lifting the main beam, and adjusting the rigid leg to be roughly vertical to the main beam, and then temporarily fixing the rigid leg to the connecting section; installing a rigid leg trolley, a flexible leg and a flexible leg trolley; pulling the main beam, and making the rigid leg reach a first set offset, and then welding the connecting section to the rigid leg. This can solve the problem in the prior art that when installing a large-tonnage crane, it is difficult to install its rigid legs to meet the requirements, resulting in heavy installation and low construction efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of lifting machinery, and in particular to a method for installing a gantry crane. Background Art

[0002] Gantry crane is a variation of bridge crane, also called gantry crane, which is a bridge crane with the bridge supported on the ground track by legs on both sides. It is mainly used for loading and unloading operations of outdoor cargo yards, material yards and bulk cargo. Gantry crane has the characteristics of high site utilization, large operating range, wide adaptability and strong versatility, and is widely used in port cargo yards.

[0003] The gantry crane is composed of a gantry, a trolley running mechanism, a lifting trolley and an electrical part. Some gantry cranes have outriggers only on one side, and the other side is supported on a factory building or a trestle for operation, which is called a semi-gantry crane. The upper bridge of the gantry of a gantry crane consists of the main beam and end beams, outriggers, lower crossbeams and other parts. In order to expand the operating range of the crane, the main beam can extend beyond the outriggers to one or both sides to form a cantilever. A lifting trolley with an arm can also be used to expand the operating range of the crane by pitching and rotating the arm.

[0004] However, in the prior art, when installing a large-tonnage crane, it is difficult to install the rigid legs to meet the requirements, which results in heavy installation and affects the construction efficiency. Summary of the invention

[0005] In view of the defects existing in the prior art, the purpose of the present invention is to provide a gantry crane installation method, which can solve the problem in the prior art that when installing a large-tonnage crane, the installation of its rigid legs is difficult to meet the requirements, resulting in heavy installation and affecting low construction efficiency.

[0006] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0007] The present invention provides a gantry crane installation method, comprising the following steps:

[0008] A connecting section is arranged at the installation position of the rigid leg under the main beam, and the inner side height of the connecting section is made lower than a first set value of the outer side height, and the outer side of the rigid leg is rotatably connected to the outer side of the connecting section;

[0009] After lifting the main beam and adjusting the rigid legs to be roughly perpendicular to the main beam, the rigid legs are temporarily fixed to the connecting section;

[0010] Install rigid leg trolley, flexible legs and flexible leg trolley;

[0011] After pulling the main beam to make the rigid leg reach the first set offset, the connecting section is welded to the rigid leg.

[0012] In some optional solutions, the installation of the rigid leg cart, the flexible legs and the flexible leg cart includes:

[0013] Lift the main beam off the ground to a level above the second set value of the theoretical elevation, and push the rigid-leg trolley and the flexible-leg trolley equipped with flexible legs to the designed position;

[0014] Lower the main beam to the theoretical elevation, partially unload the lifting load on the main beam, let the rigid legs fall onto the rigid leg trolley, and let the hinge seat under the main beam fall to the top of the flexible legs, and weld the flexible legs and the flexible leg trolley as well as the rigid legs and the rigid leg trolley.

[0015] In some optional schemes, when pushing the rigid-leg trolley and the flexible-leg trolley equipped with flexible legs to the designed position, the rigid-leg trolley and the flexible-leg trolley are adjusted until their wheel rims are in close contact with the corresponding tracks, and the transverse center line of the flexible leg coincides with the center line of the main beam, and the longitudinal center line is parallel to the corresponding track.

[0016] In some optional schemes, when the rigid leg falls onto the rigid leg trolley and the hinge seat under the main beam falls to the top of the flexible leg, the flexible leg is adjusted to be approximately vertical in the track plane, the lower crossbeam of the flexible leg is approximately parallel to the corresponding track, the top of the flexible leg is approximately parallel to the track, and the center line of the hinge seat is approximately coincident with the center line of the top of the flexible leg; at the same time, the rigid leg trolley and the flexible leg trolley are adjusted to be approximately vertical in the track plane, the lower crossbeam of the rigid leg is approximately parallel to the track, the span line at the top of the rigid leg is approximately parallel to the track, and the connecting section is approximately aligned with the rigid leg reinforcement.

[0017] In some optional solutions, after pulling the main beam to make the rigid leg reach the first set offset, welding the connecting section to the rigid leg includes:

[0018] Completely unload the lifting load of the main beam on one side of the flexible leg, and weld the hinge seat to the top of the flexible leg;

[0019] The main beam is pulled by a steel wire rope so that the rigid leg reaches a first set offset, and then the connecting section is welded to the rigid leg.

[0020] In some optional solutions, after the rigid leg reaches the first set offset, welding the connecting section to the rigid leg comprises:

[0021] After the rigid leg reaches the first set offset, the lifting load of the main beam on one side of the rigid leg is completely unloaded;

[0022] After fixing the connection section and the rigid leg by using a horse plate and positioning welding, loosen the wire rope and re-measure the vertical offset of the rigid leg to see whether it meets the requirements;

[0023] If the requirements are not met, remove the horse plate and pull the wire rope again to make the rigid leg reach the adjusted offset, and then use the horse plate and positioning welding to fix the connecting section and the rigid leg until the requirements are met; if the requirements are met, weld the connecting section and the rigid leg.

[0024] In some optional solutions, when welding the connecting section to the rigid leg,

[0025] First, weld the two outer welds parallel to the main beam in layers;

[0026] Then weld the two outer welds perpendicular to the main beam in layers, and determine whether to weld the weld on the rigid leg side or the weld on the flexible leg side first in each layer according to the shrinkage change of the rigid leg offset;

[0027] Finally, the inner welds are welded, and according to the actual offset of the rigid leg and the theoretical offset, it is determined whether to weld the two inner welds parallel to the main beam or the two inner welds perpendicular to the main beam first.

[0028] In some optional solutions, the method of determining whether to weld the weld on the rigid leg side or the weld on the flexible leg side first during each layer welding according to the shrinkage change of the rigid leg offset includes:

[0029] Weld the weld bead on one side of the rigid leg and detect the change in the offset shrinkage of the rigid leg;

[0030] If the offset shrinkage change of the rigid leg is greater than the set shrinkage value, the weld on the flexible leg side is welded first, and then the weld on the rigid leg side;

[0031] If the offset shrinkage change of the rigid leg is less than or equal to the set shrinkage value, the weld on the rigid leg side is welded first, and then the weld on the flexible leg side is welded.

[0032] In some optional solutions, the method of determining whether to weld the two inner welds parallel to the main beam or the two inner welds perpendicular to the main beam first according to the actual offset of the rigid leg and the theoretical offset includes:

[0033] Detect the offset of the rigid legs,

[0034] When the actual offset of the rigid leg is within the theoretical offset range, the two inner welds parallel to the main beam are welded first;

[0035] When the actual offset of the rigid leg is greater than the maximum value of the theoretical offset range, the inner weld on one side of the rigid leg is welded first, then the inner weld on one side of the flexible leg, and finally the two inner welds parallel to the main beam;

[0036] When the actual offset of the rigid leg is less than the minimum value of the theoretical offset range, all welds are re-welded.

[0037] In some optional solutions, after the main beam is lifted and the rigid legs are adjusted to be substantially perpendicular to the main beam, the rigid legs are temporarily fixed to the connecting section, including:

[0038] After the main beam is lifted by two parallel lifting towers to the first set height of the rigid legs off the ground, the lifting is stopped;

[0039] After placing wooden pads at the bottom of the crossbeam under the rigid legs, lower the main beam so that the crossbeam under the rigid legs falls on the wooden pads;

[0040] After adjusting the rigid leg to be roughly perpendicular to the main beam, the rigid leg and the connecting section are temporarily fixed by using a horse plate and positioning welding.

[0041] Compared with the prior art, the advantages of the present invention are: by setting a connecting section at the installation position of the rigid leg under the main beam, and making the inner height of the connecting section lower than the first set value of the outer height, the outer side of the rigid leg is rotatably connected to the outer side of the connecting section; after lifting the main beam and adjusting the rigid leg to be roughly perpendicular to the main beam, the rigid leg is temporarily fixed to the connecting section; then the rigid leg trolley, flexible leg and flexible leg trolley are installed; finally, the main beam is pulled to make the rigid leg reach the first set offset, and then the connecting section is welded to the rigid leg. Finally, it is ensured that after the gantry crane is installed, the vertical offset of the rigid leg in the theoretical state can meet the requirements, avoiding the problem of unqualified installation of the rigid leg requiring re-welding, which affects the construction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0043] Figure 1 It is a schematic diagram of the front view of a gantry crane in an embodiment of the present invention;

[0044] Figure 2 It is a right side schematic diagram of a gantry crane in an embodiment of the present invention;

[0045] Figure 3 It is a left side schematic diagram of a gantry crane in an embodiment of the present invention;

[0046] Figure 4 Schematic diagram of theoretical offset before welding of the rigid leg and the connecting section in an embodiment of the present invention;

[0047] Figure 5 Schematic diagram of theoretical layout of the connection section in an embodiment of the present invention;

[0048] Figure 6This is a schematic diagram of starting to lift the main beam in an embodiment of the present invention;

[0049] Figure 7 It is a schematic diagram of a steel wire rope pulling a main beam in an embodiment of the present invention;

[0050] Figure 8 is a schematic diagram of a weld between a rigid leg and a connecting section in an embodiment of the present invention;

[0051] Fig. 9 Schematic diagram of welding of each layer of the weld in an embodiment of the present invention.

[0052] In the figure: 1. main beam; 2. rigid leg; 21. cross beam under rigid leg; 3. connecting section; 41. rigid leg trolley; 42. flexible leg trolley; 5. flexible leg; 51. cross beam under flexible leg; 6. wire rope; 7. lifting tower; 8. hinge seat. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0054] The embodiments of the present invention are further described in detail below with reference to the accompanying drawings.

[0055] like Figures 1 to 7 As shown, the present invention provides a gantry crane installation method, comprising the following steps:

[0056] See also Figure 4 and Figure 5 As shown, S1: a connecting section 3 is arranged at the installation position of the rigid leg 2 under the main beam 1, and the inner side height of the connecting section 3 is lower than the first set value of the outer side height, and the outer side of the rigid leg 2 is rotatably connected to the outer side of the connecting section 3. In this example, the outer side of the rigid leg 2 is hinged to the outer side of the connecting section 3.

[0057] In this embodiment, the gantry crane is a 200t shipbuilding gantry crane. Under theoretical conditions, the vertical offset of the rigid leg 2 is required to be 80mm to 120mm, and the theoretical elevation of the connecting section is 720mm. After the rigid leg 2 is assembled and before welding, the vertical offset of the rigid leg 2 is controlled to be 120+30mm, which can achieve the best load-bearing effect.

[0058] In this example, in order to ensure that the vertical offset of the rigid leg 2 is controlled within 120+30mm after the rigid leg 2 is assembled and before welding, the height of the inner side of the connecting section 3 is 720mm and the height of the outer side is 740mm after theoretical lofting. Even if the inner height of the connecting section 3 is lower than the first setting value of the outer height, the first setting value is 20mm. In other embodiments, it can be set according to actual needs.

[0059] S2: After lifting the main beam 1 and adjusting the rigid leg 2 to be roughly vertical to the main beam 1, the rigid leg 2 and the connecting section 3 are temporarily fixed.

[0060] like Figure 6 As shown, in some optional embodiments, step S2 includes:

[0061] S21: After the main beam 1 is lifted by two parallel lifting towers 7 until the rigid legs 2 are off the ground to a first set height, the lifting is stopped.

[0062] In this example, two lifting towers 7 are arranged in parallel, one lifting tower 7 is arranged on each side of the rigid leg 2 and the flexible leg 5, and the main beam 1 is lifted by a winch arranged on the ground. In this example, the main beam 1 is lifted to a height of 500 mm above the ground when the cross beam 21 under the rigid leg is lifted, and then the lifting is stopped.

[0063] S22: After placing a wooden pad at the bottom of the cross beam 21 under the rigid leg, lower the main beam 1 so that the cross beam 21 under the rigid leg falls on the wooden pad.

[0064] In this example, wooden pads are placed on the ground at the bottom of the cross beam 21 under the rigid legs, and should be lowered slowly when the main beam 1 is lowered.

[0065] S23: After adjusting the rigid leg 2 to be roughly perpendicular to the main beam 1, the rigid leg 2 and the connecting section 3 are temporarily fixed by using a horse plate and positioning welding.

[0066] In this embodiment, adjusting the rigid leg 2 to be substantially perpendicular to the main beam 1 refers to roughly adjusting the verticality of the rigid leg 2 in the track plane to ≤20 mm. If the verticality of the rigid leg 2 in the track plane is ≤20 mm, the rigid leg 2 is considered to be substantially perpendicular to the main beam 1.

[0067] S3: Install the rigid leg cart 41, the flexible leg 5 and the flexible leg cart 42.

[0068] In this embodiment, step S3 specifically includes:

[0069] S31: Lift the main beam 1 off the ground to a level higher than the second set value of the theoretical elevation, and push the rigid leg trolley 41 and the flexible leg trolley 42 equipped with the flexible legs 5 to the designed positions.

[0070] In this embodiment, the main beam 1 is lifted off the ground to 100 mm above the theoretical elevation, that is, the second set value is 100 mm.

[0071] In some optional embodiments, when pushing the rigid leg cart 41 and the flexible leg cart 42 equipped with the flexible legs 5 to the designed position, the rigid leg cart 41 and the flexible leg cart 42 are adjusted until their wheel rims are in close contact with the corresponding tracks, and the transverse center line of the flexible legs 5 coincides with the center line of the main beam 1, and the longitudinal center line is parallel to the corresponding track.

[0072] In this example, adjusting the rigid-leg cart 41 and the flexible-leg cart 42 until their wheel rims are in close contact with the corresponding tracks refers to adjusting the wheels of the rigid-leg cart 41 and the flexible-leg cart 42 to be clamped on the tracks.

[0073] S32: Lower the main beam 1 to the theoretical elevation, partially unload the lifting load on the main beam 1, let the rigid leg 2 fall onto the rigid leg trolley 41, and let the hinge seat 8 under the main beam 1 fall to the top of the flexible leg 5, and weld the flexible leg 5 and the flexible leg trolley 42 as well as the rigid leg 2 and the rigid leg trolley 41.

[0074] In some optional embodiments, when the rigid leg 2 falls onto the rigid leg trolley 41 and the hinge seat 8 under the main beam 1 falls to the top of the flexible leg 5, the flexible leg 5 is adjusted to be approximately vertical in the plane of the track, the lower cross beam 51 of the flexible leg is approximately parallel to the corresponding track, the top of the flexible leg 5 is approximately parallel to the track, and the center line of the hinge seat 8 is approximately coincident with the center line of the top of the flexible leg 5; at the same time, the rigid leg trolley 41 and the flexible leg trolley 42 are adjusted to be approximately vertical in the plane of the track, the lower cross beam 21 of the rigid leg is approximately parallel to the track, the span line at the top of the rigid leg 2 is approximately parallel to the track, and the connecting section 3 is approximately aligned with the ribs of the rigid leg 2.

[0075] In this embodiment, the track is a track for the sliding of the rigid leg trolley 41 and the flexible leg trolley 42. The flexible leg 5 is adjusted to ensure that the verticality of the flexible leg 5 in the plane of the track is ≤20mm, that is, roughly vertical, and the parallelism of the lower cross beam 51 of the flexible leg and the track is ≤2mm, that is, roughly parallel. The top of the flexible leg 5 is an A-head, so that its parallelism with the track is ≤2mm, that is, roughly parallel. The hinge seat 8 is installed under the main beam 1 to connect the flexible hinge seat with the top of the flexible leg 5 as an A-head, so that the center line of the flexible hinge seat coincides with the cross center line of the top of the A-head by ≤2mm, that is, roughly coincide; at the same time, adjust the verticality of the rigid leg 2 and the flexible leg 5 in their respective track planes to ≤20mm, that is, roughly vertical, the parallelism of the lower cross beam 21 of the rigid leg and the track is ≤2mm, that is, roughly parallel, the parallelism of the top 100m span line of the rigid leg 2 and the track is ≤5mm, that is, roughly parallel, and the misalignment of the ribs of the connecting section 3 and the rigid leg 2 is ≤2mm, that is, roughly aligned.

[0076] In this example, partially unloading the lifting load on the main beam 1 means unloading 80% of the lifting load on both sides of the rigid leg 2 and the flexible leg 5, that is, unloading the winch by 80%. When welding the rigid leg lower cross beam 21 and the rigid leg trolley 41, and the flexible leg lower cross beam 51 and the flexible leg trolley 42, the welding is performed symmetrically on the same side.

[0077] like Figure 7 As shown, S4: after pulling the main beam 1 so that the rigid leg 2 reaches a first set offset, the connecting section 3 is welded to the rigid leg 2.

[0078] In some optional embodiments, step S4 specifically includes:

[0079] S41: Completely unload the lifting load of the main beam 1 on one side of the flexible leg 5 and weld the hinge seat 8 to the top of the flexible leg 5 .

[0080] After the welding between the flexible leg 5 and the flexible leg trolley 42 and between the rigid leg 2 and the rigid leg trolley 41 is completed, the lifting load of the flexible leg 5 on the main beam 1 is completely unloaded. Then retest, if it does not meet the requirements, make adjustments in time until it meets the requirements, and then weld the weld between the hinge seat 8 and the top A-head of the flexible leg 5.

[0081] S42: After the main beam 1 is pulled by the steel wire rope 6 so that the rigid leg 2 reaches a first set offset, the connecting section 3 is welded to the rigid leg 2 .

[0082] Step S42 specifically includes:

[0083] S421: After the rigid leg 2 reaches the first set offset, the lifting load of the main beam 1 on one side of the rigid leg 2 is completely unloaded.

[0084] In this embodiment, in order to meet the theoretical requirement of a vertical offset of 80 mm to 120 mm for the rigid leg 2, a positioning wire rope 6 is used to connect one side of the rigid leg 2 of the main beam 1, and the position of the main beam 1 is adjusted so that the top of the rigid leg 2 is offset 150 ± 5 mm outward, that is, the first set offset is 150 mm.

[0085] S422: After fixing the connection section 3 to the rigid leg 2 using a horse plate and tack welding, loosen the wire rope 6 and re-measure whether the vertical offset of the rigid leg 2 meets the requirements. Also re-measure the parallelism between the top 100m span line of the rigid leg 2 and the track.

[0086] If the requirements are not met, remove the horse plate and pull the wire rope 6 again to make the rigid leg 2 reach the adjusted offset, and then use the horse plate and positioning welding to fix the connecting section 3 and the rigid leg 2 until the requirements are met; if the requirements are met, weld the connecting section 3 and the rigid leg 2.

[0087] Before welding the connecting section 3 to the rigid leg 2, ensure that all the steel wire ropes 6 are in a relaxed state to prevent the steel wire ropes from affecting the vertical offset of the rigid leg 2 after welding.

[0088] like Figure 8 and Fig. 9 As shown, in some optional embodiments, when the connecting section 3 is welded to the rigid leg 2,

[0089] A: First weld the two outer welds parallel to the main beam 1 in layers.

[0090] In this example, when welding two outer welds parallel to the main beam 1, two welders weld symmetrically from one side of the flexible leg 5 to the other side of the rigid leg 2, and detect the offset of the rigid leg 2 after welding each layer of welds.

[0091] B: Weld the two outer welds perpendicular to the main beam 1 in layers, and according to the shrinkage change of the offset of the rigid leg 2, determine whether to weld the weld on the side of the rigid leg 2 or the weld on the side of the flexible leg 5 first in each layer of welding.

[0092] In some optional embodiments, according to the shrinkage change of the offset of the rigid leg 2, determining whether to weld the weld on one side of the rigid leg 2 or the weld on one side of the flexible leg 5 first during each layer welding includes:

[0093] Weld the weld on the side of the rigid leg 2 and detect the offset shrinkage change of the rigid leg 2; if the offset shrinkage change of the rigid leg 2 is greater than the set shrinkage value, first weld the weld on the side of the flexible leg 5, then weld the weld on the side of the rigid leg 2. If the offset shrinkage change of the rigid leg 2 is less than or equal to the set shrinkage value, first weld the weld on the side of the rigid leg 2, then weld the weld on the side of the flexible leg 5.

[0094] In this example, the weld on one side of the rigid leg 2 and the weld on one side of the flexible leg 5 refer to two outer welds perpendicular to the main beam 1 .

[0095] When initially welding the weld on one side of the rigid leg 2, two welders weld from the middle and outside the two sides. When welding the weld on one side of the flexible leg 5, two welders weld symmetrically from the middle to the two sides. In this example, the shrinkage value is set according to actual needs, generally 3-8mm.

[0096] C: Finally, perform the inner weld welding, and determine whether to weld the two inner welds parallel to the main beam 1 or the two inner welds perpendicular to the main beam 1 first based on the actual offset and theoretical offset of the rigid leg 2.

[0097] In some optional embodiments, determining whether to weld two inner welds parallel to the main beam 1 first or to weld two inner welds perpendicular to the main beam 1 comprises:

[0098] Detect the offset of the rigid leg 2. When the actual offset of the rigid leg 2 is within the theoretical offset range, first weld the two inner welds parallel to the main beam 1; when the actual offset of the rigid leg 2 is greater than the maximum value of the theoretical offset range, first weld the inner weld on one side of the rigid leg 2, then weld the inner weld on one side of the flexible leg 5, and finally weld the two inner welds parallel to the main beam 1; when the actual offset of the rigid leg 2 is less than the minimum value of the theoretical offset range, re-weld all welds.

[0099] In this example, the theoretical offset range is 80~120mm, the maximum value of the theoretical offset range is 120mm, and the minimum value of the theoretical offset range is 80mm.

[0100] The following is a specific embodiment of welding the connecting section 3 to the rigid leg 2, in which the rigid leg 2 is located on the north side, the flexible leg 5 is located on the south side, the two outer welds parallel to the main beam 1 are the two welds on the east and west sides, and the two outer welds perpendicular to the main beam 1 are the welds on the north and south sides.

[0101] When welding the connection section 3 to the rigid leg 2, first weld the two welds on the east and west sides (the rigid leg is on the north side and the flexible leg is on the south side). During welding, two welders weld symmetrically from south to north, and detect the offset of the rigid leg after welding each layer of welds. After welding the welds on the east and west sides, start welding the weld on the north side of the connection section. During welding, two welders weld from the middle and outside the two sides; after welding the base layer of the north weld, detect the offset of the rigid leg; if the offset shrinks greatly, then use the first two welders to weld the base layer of the south weld symmetrically from the middle to the two sides, and then detect the offset of the rigid leg; and so on, the north and south sides of the connection section are welded alternately, and after each layer of welds is welded, the inclination value is monitored, and the north or south weld is determined according to the speed of the offset change. After the outer girth weld is completed and before the inner girth weld is welded, if the offset is between 80 and 120 mm, weld the east and west side welds first, then weld the north and south side welds; if the offset is greater than 120 mm, weld the north side weld first, then weld the south side weld, and finally weld the east and west side welds; if the offset is less than 80 mm, all welds are re-welded.

[0102] In addition, there is a certain deviation in the total height and top surface flatness of the rigid leg 2 after on-site assembly. The cumulative assembly error of the rigid leg 2 needs to be offset by the connecting section. Therefore, the height of the connecting section 3 can be adjusted by cutting it in combination with the accuracy of the rigid leg 2.

[0103] In order to ensure that the height difference between the rigid leg 2 and the flexible leg 5 is ≤25mm after installation, the height deviation of the flexible leg 5 needs to be offset by the connecting section 3. Therefore, the connecting section 3 needs to be adjusted for the third cutting height in combination with the accuracy of the flexible leg 5. The spacing of the reaming holes of the towing hinge of the rigid leg 2 can be determined in combination with the above-mentioned height adjustment.

[0104] In summary, by setting a connecting section at the installation position of the rigid leg under the main beam, and making the inner height of the connecting section lower than the first set value of the outer height, the outer side of the rigid leg is rotatably connected to the outer side of the connecting section; after lifting the main beam and adjusting the rigid leg to be roughly perpendicular to the main beam, the rigid leg is temporarily fixed to the connecting section; then the rigid leg trolley, flexible leg and flexible leg trolley are installed; finally, the main beam is pulled to make the rigid leg reach the first set offset, and then the connecting section is welded to the rigid leg. Finally, it is ensured that after the gantry crane is installed, the vertical offset of the rigid leg in the theoretical state can meet the requirements, avoiding the problem of unqualified installation of the rigid leg requiring re-welding, which affects the construction efficiency.

[0105] In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0106] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0107] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A method for installing a gantry crane, characterized in that: The following steps are involved: A connecting section (3) is provided at the installation position of the rigid leg (2) under the main beam (1), and the inner side height of the connecting section (3) is made lower than a first set value of the outer side height, and the outer side of the rigid leg (2) is rotatably connected to the outer side of the connecting section (3); After lifting the main beam (1) and adjusting the rigid legs (2) to be approximately perpendicular to the main beam (1), the rigid legs (2) and the connecting section (3) are temporarily fixed, including: Using two parallel lifting towers (7) to lift the main beam (1) until the rigid legs (2) are at a first set height above the ground, the lifting is stopped; After placing a wooden pad at the bottom of the cross beam (21) under the rigid leg, lowering the main beam (1) so that the cross beam (21) under the rigid leg falls on the wooden pad; After adjusting the rigid leg (2) to be approximately perpendicular to the main beam (1), the rigid leg (2) and the connecting section (3) are temporarily fixed by using a saddle plate and positioning welding; The rigid leg trolley (41), the flexible leg (5) and the flexible leg trolley (42) are installed, comprising: Lifting the main beam (1) off the ground to a height above a second set value of the theoretical elevation, and pushing the rigid leg trolley (41) and the flexible leg trolley (42) equipped with flexible legs (5) to the designed positions; Lower the main beam (1) to the theoretical elevation, partially unload the lifting load on the main beam (1), let the rigid leg (2) fall onto the rigid leg trolley (41), and let the hinge seat (8) under the main beam (1) fall onto the top of the flexible leg (5), and weld the flexible leg (5) and the flexible leg trolley (42) as well as the rigid leg (2) and the rigid leg trolley (41); After the main beam (1) is pulled so that the rigid leg (2) reaches a first set offset, the connecting section (3) is welded to the rigid leg (2).

2. The gantry crane installation method according to claim 1, characterized in that: When the rigid leg trolley (41) and the flexible leg trolley (42) equipped with the flexible leg (5) are pushed to the designed position, the rigid leg trolley (41) and the flexible leg trolley (42) are adjusted until their wheel rims are in close contact with the corresponding tracks, and the transverse center line of the flexible leg (5) is coincident with the center line of the main beam (1), and the longitudinal center line is parallel to the corresponding track.

3. The gantry crane installation method according to claim 1, characterized in that: When the rigid leg (2) is dropped onto the rigid leg trolley (41) and the hinge seat (8) below the main beam (1) is dropped onto the top of the flexible leg (5), the flexible leg (5) is adjusted to be approximately vertical in the plane of the track, the cross beam (51) below the flexible leg is approximately parallel to the corresponding track, the top of the flexible leg (5) is approximately parallel to the track, and the center line of the hinge seat (8) is approximately coincident with the center line of the top of the flexible leg (5); at the same time, the rigid leg trolley (41) and the flexible leg trolley (42) are adjusted to be approximately vertical in the plane of the track, the cross beam (21) below the rigid leg is approximately parallel to the track, the span line at the top of the rigid leg (2) is approximately parallel to the track, and the connecting section (3) is approximately aligned with the ribs of the rigid leg (2).

4. The gantry crane installation method according to claim 1, characterized in that: The pulling of the main beam (1) so that the rigid leg (2) reaches a first set offset, and then welding the connecting section (3) to the rigid leg (2) comprises: Completely unloading the lifting load of the main beam (1) on one side of the flexible leg (5), and welding the hinge seat (8) to the top of the flexible leg (5); The main beam (1) is pulled by a steel wire rope (6) so that the rigid leg (2) reaches a first set offset, and then the connecting section (3) is welded to the rigid leg (2).

5. The gantry crane installation method according to claim 4, characterized in that: The method of welding the connection section (3) to the rigid leg (2) after the rigid leg (2) reaches the first set offset comprises: After the rigid leg (2) reaches a first set offset, the lifting load of the main beam (1) on one side of the rigid leg (2) is completely unloaded; After fixing the connecting section (3) and the rigid leg (2) by using a horse plate and positioning welding, loosening the steel wire rope (6) and re-measuring whether the vertical offset of the rigid leg (2) meets the requirements; If the requirements are not met, the horse plate is removed and the steel wire rope (6) is re-pulled to make the rigid leg (2) reach the adjusted offset, and then the horse plate and positioning welding are used to fix the connecting section (3) and the rigid leg (2) until the requirements are met; if the requirements are met, the connecting section (3) and the rigid leg (2) are welded.

6. The gantry crane installation method according to claim 5, characterized in that: When welding the connecting section (3) to the rigid leg (2), First, two outer welds parallel to the main beam (1) are welded in layers; Then, two outer welds perpendicular to the main beam (1) are welded in layers, and according to the shrinkage change of the offset of the rigid leg (2), it is determined whether to weld the weld on one side of the rigid leg (2) or the weld on one side of the flexible leg (5) first in each layer of welding; Finally, the inner welds are welded, and according to the actual offset of the rigid leg (2) and the theoretical offset, it is determined whether to weld the two inner welds parallel to the main beam (1) or the two inner welds perpendicular to the main beam (1) first.

7. The gantry crane installation method according to claim 6, characterized in that: The method of determining whether to weld the weld bead on one side of the rigid leg (2) or the weld bead on one side of the flexible leg (5) first during each layer welding according to the shrinkage change of the offset of the rigid leg (2) comprises: Welding a weld bead on one side of the rigid leg (2) and detecting a change in the offset shrinkage of the rigid leg (2); If the offset shrinkage change of the rigid leg (2) is greater than the set shrinkage value, the weld on one side of the flexible leg (5) is welded first, and then the weld on one side of the rigid leg (2) is welded; If the offset shrinkage change of the rigid leg (2) is less than or equal to the set shrinkage value, the weld on one side of the rigid leg (2) is welded first, and then the weld on one side of the flexible leg (5) is welded.

8. The gantry crane installation method according to claim 6, characterized in that: The method of determining whether to weld the two inner welds parallel to the main beam (1) or the two inner welds perpendicular to the main beam (1) first according to the actual offset of the rigid leg (2) and the theoretical offset comprises: Detect the deflection of the rigid leg (2), When the actual offset of the rigid leg (2) is within the theoretical offset range, two inner welds parallel to the main beam (1) are first welded; When the actual offset of the rigid leg (2) is greater than the maximum value of the theoretical offset range, the inner weld on one side of the rigid leg (2) is welded first, then the inner weld on one side of the flexible leg (5), and finally the two inner welds parallel to the main beam (1); When the actual offset of the rigid leg (2) is less than the minimum value of the theoretical offset range, all welds are re-welded.

Images