A method for installing and welding a marine gantry crane track

Abstract

The present invention relates to a method for installing and welding a marine gantry crane track, comprising a track, a channel steel base placed at the bottom end of the track, a bottom plate fixedly connected to the bottom end of the channel steel base, the channel steel base being arranged in a C shape, the number of the bottom plates being arranged in two, and a fixing frame placed on the inner side of the channel steel base. By arranging a track and an adjusting rod, 12 mm of non-welding is left at both ends of the weld, which mainly serves to release welding stress and avoid various defects caused by welding stress. During welding, the prescribed marine gantry crane track is installed by welding, which has the characteristics of high strength and simple later maintenance. If a pressure plate is used to fix the gantry crane track, the pressure plate will be severely corroded due to environmental influences during actual operation of the ship, and the corrosion of the pressure plate needs to be frequently checked and replaced in time. In comparison, the welding type is more convenient to maintain, greatly improves maintenance efficiency, reduces maintenance costs, effectively enhances the use strength of the track, and increases service life.

Description

Technical Field

[0001] The invention relates to the technical field of marine welding, in particular to an installation and welding method for a marine gantry crane track. Background Art

[0002] Conventional marine gantry crane tracks are secured with a pressure plate. During installation, a retaining pin must be driven into the center of the track (or welded in place), with positioning blocks installed on both sides and a pressure plate secured to the track surface. This centering fixation ensures that the track can expand and contract evenly to both ends due to thermal expansion and contraction.

[0003] The owner of the 26000 self-unloading vessel required that the marine gantry crane tracks for this project be fixed by welding. The welding method has the advantages of high strength and easy maintenance. At the same time, the welding method also has special requirements for the track material and installation welding process, and the risks of various stresses on the track need to be controlled. Summary of the Invention

[0004] In order to solve the problems of the prior art, the present invention provides a method for installing and welding a marine gantry crane track.

[0005] In order to solve the above technical problems, the present invention is achieved through the following technical solutions:

[0006] The present invention discloses an installation and welding method for a marine gantry crane track, comprising a track, a channel steel base placed at the bottom end of the track, a bottom plate fixedly connected to the bottom end of the channel steel base, the channel steel base being arranged in a C shape, the number of the bottom plates being arranged in two, a fixing frame placed on the inner side of the channel steel base, a fixing seat being fixedly connected to the top side of the fixing frame, a telescopic block being transmission-connected to the bottom end of the fixing seat, an adjusting rod being rotatably connected to one side of the telescopic block, an outer wall of the track being covered with thick thermal insulation cotton, and an I-shaped cross-sectional shape of the track.

[0007] A method for installing and welding a marine gantry crane track comprises the following steps:

[0008] Step 1: Place the finished channel steel base on the tooling platform, ensure that the upper surface of the channel steel base (2) is level, and fix the rails on the channel steel base according to the drawing requirements. The gap between the rails and the upper surface of the channel steel base should not exceed 1mm. Note: Spot welding is prohibited for temporary fixing of the rails, and they should be fixed with pressure plates.

[0009] Step 2: Before welding, it is necessary to check that the bottom surface of the rail and the contact surface of the channel steel base are tightly fitted and the welding area is free of rust, oil, water and paint. Use a fixing frame to fix it and check the installation position of the rail to ensure it is accurate before preheating before welding;

[0010] Step 3: Preheat both sides of the track simultaneously with a drying gun. The preheating area is the junction between the track and the channel bottom, as well as the area extending 30-50mm outward on both sides of the junction. The entire preheating area is heated to above 260°C. The temperature is tested with a far-infrared thermometer, and the parameters are recorded on site in the workshop.

[0011] Step 4: After preheating, welding should be carried out immediately. Multi-layer and multi-pass welding should be adopted. The temperature between welding layers should not be lower than the preheating temperature and should not exceed 300°C. Two welders should be arranged to weld on both sides of the track at the same time. Note that the starting and ending ends of the weld must be rounded and free of pores, slag inclusions, and shrinkage defects. Each layer and each pass must be cleaned before the next pass can be welded.

[0012] Step 5: After the rail and channel steel base are welded, heat them to 260℃~500℃ immediately. Use a drying gun to preheat both sides of the rail at the same time. The heating area is the area where the rail and channel steel are combined and extends 50-100mm. Maintain the temperature for 2 minutes and then immediately wrap with thick insulation cotton to slow cooling. The bottom of the rail steel must also be wrapped in place.

[0013] Step 6: Keep the rail weld 12mm away from the edge of the channel steel base, and the arc striking and extinguishing ends must be full and round;

[0014] Step 7. Welding sequence of rails and channel steel base: weld one by one from the middle channel steel base of the rail to both sides. Do not weld the connecting plates at the end of the rails. Be careful not to offset the position of the rail steel and the channel steel base. When welding, be sure to check the rail installation size requirements. They must be within the tolerance requirements specified in the design drawings. After the first rail is welded, the remaining rails must be welded in the same direction as the first rail.

[0015] Step 8: The rail will extend after being heated, causing the mark points of the rail and the channel steel base to be misaligned. Before welding, the mark point position must be checked. Before welding the rail and the channel steel base, the temperature of the previous adjacent welding position must be tested after insulation and slow cooling. Welding can only be carried out after the temperature cools to room temperature of 25-30℃.

[0016] Step nine: Complete the welding between the rail and the channel steel base in accordance with the welding process requirements. During the welding process, the temperature of preheating before welding and heat treatment after welding must be strictly controlled to ensure that the welding of the entire rail steel and the channel steel base is completed.

[0017] The beneficial effects of the present invention are as follows: by setting the track and the adjusting rod, 12mm is left unwelded at both ends of the weld, which mainly serves to release welding stress, thereby avoiding various defects caused by welding stress. When welding, the specified marine gantry crane track 1 is installed by welding, which has the characteristics of high strength and simple later maintenance. If a pressure plate type is used to fix the gantry crane track, the pressure plate will be severely corroded due to environmental influences during actual operation of the ship, and the rust condition of the pressure plate needs to be frequently checked and replaced in time. In comparison, the welding type is more convenient to maintain, greatly improves maintenance efficiency, reduces maintenance costs, effectively enhances the use strength of the track, and increases service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the track fixing structure of the present invention.

[0019] Figure 2 It is a schematic diagram of track preheating of the present invention.

[0020] Figure 3 It is a schematic diagram of the track rear hot track of the present invention.

[0021] Figure 4 It is a schematic diagram of the track insulation structure of the present invention.

[0022] Figure 5 It is a schematic structural diagram of the orbital welding finished product of the present invention.

[0023] Figure 6 It is a schematic diagram of the orbital welding sequence of the present invention.

[0024] Figures 1 to 6 Middle: 1. Track; 2. Channel steel base; 3. Bottom plate; 4. Fixed frame; 5. Fixed seat; 6. Telescopic block; 7. Adjustment rod; 8. Thick insulation cotton. DETAILED DESCRIPTION

[0025] like Figures 1 to 6The shown method for installing and welding a marine gantry crane track includes a track 1, a channel steel base 2 is placed at the bottom end of the track 1, and the bottom end of the channel steel base 2 is fixedly connected to a bottom plate 3. The bottom plate 3 enhances the ground contact area of ​​the channel steel base 2 and further enhances stability. The channel steel base 2 is set to a C shape, and the number of bottom plates 3 is set to two. A fixing frame 4 is placed on the inner side of the channel steel base 2, and a fixing seat 5 is fixedly connected to the top side of the fixing frame 4. The bottom end of the fixing seat 5 is transmission-connected with a telescopic block 6, and one side of the telescopic block 6 is rotatably connected to an adjusting rod 7. The outer wall of the track 1 is covered with thick insulation cotton 8, and the cross-sectional shape of the track 1 is set to an I shape. When welding, the specified marine gantry crane track 1 is installed by welding, which has the characteristics of high strength and simple later maintenance. If a pressure plate type is used to fix the gantry crane track, the pressure plate will be severely corroded due to environmental influences during actual operation of the ship, and the rust of the pressure plate needs to be frequently checked and replaced in the later stage. In comparison, the welding type is more convenient for maintenance, greatly improves maintenance efficiency, reduces maintenance costs, and enhances the use effect.

[0026] A method for installing and welding a marine gantry crane track comprises the following steps:

[0027] Step 1: Place the finished channel steel base 2 on the tooling platform, ensure that the upper surface of the channel steel base (2) is level, and fix the track 1 on the channel steel base 2. The gap between the track 1 and the upper surface of the channel steel base 2 should not exceed 1 mm. Note: Spot welding is prohibited for temporary fixation of the track 1, and it should be fixed with a pressure plate.

[0028] Step 2: Before welding, it is necessary to check that the bottom surface of the track 1 is in close contact with the contact surface of the channel steel base 2 and that there is no rust, oil, or water paint in the welding area. Use the fixing frame 4 to fix it and check the installation position of the track 1 to ensure that it is accurate before preheating before welding;

[0029] Step 3: Preheat both sides of the track simultaneously with a drying gun. The preheating area is the junction between the track 1 and the channel steel base 2, as well as the area extending 30-50mm outward on both sides of the junction. The entire preheating area is heated to above 260°C. A far-infrared thermometer is used to measure the temperature, and the parameters are recorded on site in the workshop.

[0030] Step 4: After preheating, welding should be carried out immediately. Multi-layer and multi-pass welding should be adopted. The temperature between welding layers should not be lower than the preheating temperature and should not exceed 300°C. Two welders should be arranged to weld on both sides of the track at the same time. Note that the starting and ending ends of the weld must be rounded and free of pores, slag inclusions, and shrinkage defects. Each layer and each pass must be cleaned before the next pass can be welded.

[0031] Step 5: After the track 1 and the channel steel base 2 are welded, heat them to 260°C~500°C immediately. Use a drying gun to preheat both sides of the track. The heating area is the area where the track and the channel steel are connected and extends 50-100mm. After maintaining the temperature for 5 minutes, immediately wrap them with thick insulation cotton 8 to slow down the cooling. The bottom of the track 1 steel must also be wrapped in place.

[0032] Step 6: Keep the weld of track 1 12mm away from the edge of channel steel base 2, and the arc striking and extinguishing ends must be full and round;

[0033] Step 7, welding order of track 1 and channel steel base 2: weld one by one from the middle channel steel base 2 position of track 1 to both sides. Do not weld the connecting plate position of track 1 end. Be careful not to offset the position of track 1 steel and channel steel base 2. When welding, be sure to check the installation size requirements of track 1. It must be within the tolerance requirements specified in the design drawings. After the first track 1 is welded, the remaining tracks 1 must be welded in the same direction as the first track 1.

[0034] Step 8: Rail 1 stretches after being heated, causing the mark points of rail 1 and channel steel base 2 to be misaligned. Before welding, the mark point position must be checked. Before welding rail 1 and channel steel base 2, the temperature of the previous adjacent welding position must be checked after insulation and slow cooling. Welding can only be carried out after the temperature cools to room temperature of 25-30°C.

[0035] Step nine, complete the welding between the track 1 and the channel steel base 2 according to the welding process requirements. During the welding process, the temperature of preheating before welding and heat treatment after welding must be strictly controlled to ensure that the welding of the entire track 1 steel and the channel steel base 2 is completed.

[0036] In summary, the present invention has the following beneficial effects: when in use, 12mm is left unwelded at both ends of the weld, the main function of which is to release welding stress, thereby avoiding various defects caused by welding stress. When welding, the specified ship gantry crane track 1 is installed by welding, which has the characteristics of high strength and simple later maintenance. If a pressure plate type is used to fix the gantry crane track, the pressure plate will be severely corroded due to environmental influences during actual operation of the ship, and the rust condition of the pressure plate needs to be frequently checked and replaced in time. In comparison, the welding type is more convenient for maintenance, greatly improves maintenance efficiency, and reduces maintenance costs. By adopting this welding method, the rust condition of the hull pressure plate can be effectively avoided, the track use effect can be enhanced, and the service life of the track can be extended.

[0037] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for installing and welding a marine gantry crane track, comprising a track (1), characterized in that: A channel steel base (2) is placed at the bottom end of the track (1), and a bottom plate (3) is fixedly connected to the bottom end of the channel steel base (2). The channel steel base (2) is set to be C-shaped, and the number of the bottom plates (3) is set to two. A fixing frame (4) is placed on the inner side of the channel steel base (2), and a fixing seat (5) is fixedly connected to the top side of the fixing frame (4). The bottom end of the fixing seat (5) is transmission-connected to a telescopic block (6), and one side of the telescopic block (6) is rotatably connected to an adjusting rod (7). The cross-sectional shape of the track (1) is set to be an I-shaped, and the welding method includes: Step 1: Place the finished channel steel base (2) on the tooling platform, ensure that the upper surface of the channel steel base (2) is level, and fix the track (1) on the channel steel base (2). The gap between the track (1) and the upper surface of the channel steel base (2) should not exceed 1mm. Note: Spot welding is prohibited for temporary fixation of the track (1), and it should be fixed with a pressure plate. Step 2: Before welding, it is necessary to check that the bottom surface of the track (1) and the contact surface of the channel steel base (2) are tightly fitted and that there is no rust, oil, or water paint in the welding area. The track (1) is fixed with a fixing frame (4) and the installation position of the track (1) is checked to ensure that it is accurate before preheating before welding. Step 3: Preheat both sides of the track (1) with a drying gun at the same time. The preheating area is the junction area between the track (1) and the channel steel base (2) and the area extending 30-50 mm outward on both sides of the junction area. The entire preheating area is heated to above 260°C, and a far-infrared thermometer is used for testing. The parameters are recorded on site in the workshop; Step 4: After preheating, welding should be carried out immediately. Multi-layer and multi-pass welding should be adopted. The temperature between welding layers should not be lower than the preheating temperature and should not exceed 300°C. Two welders should be arranged to weld on both sides of the track at the same time. Note that the starting and ending ends of the weld must be rounded and free of pores, slag inclusions, and shrinkage defects. Each layer and each pass must be cleaned before the next pass can be welded. Step 5. After the rail (1) and the channel steel base (2) are welded, heat the rail (1) and the channel steel base (2) to 260°C~500°C immediately. Use a drying gun to preheat both sides of the rail. The heating area is the joint area between the rail (1) and the channel steel base (2) and the area extending 50-100mm outward on both sides of the joint area. After maintaining the temperature for 5 minutes, immediately wrap it with thick insulation cotton (8) to slow down the cooling. The steel bottom of the rail (1) must also be wrapped in place. Step 6: The weld of the track (1) should be kept 12mm away from the edge of the channel steel base (2), and the arc striking and extinguishing end must be full and rounded; Step 7, welding order of track (1) and channel steel base (2): weld one by one from the position of channel steel base (2) in the middle of track (1) to both sides. Do not weld the connecting plate position at the end of track (1). Be careful not to offset the position of track (1) steel and channel steel base (2). When welding, be sure to check the installation size requirements of track (1) and must be within the tolerance requirements specified in the design drawings. Step 8: The track (1) stretches after being heated, causing the track (1) and the channel steel base (2) to be misaligned. Before welding, the position of the mark point must be checked. Before welding the track (1) and the channel steel base (2), the temperature of the previous adjacent welding position must be checked after insulation and slow cooling. Welding can only be carried out after the temperature cools to room temperature of 25 to 30°C.

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