Installation method of steel castings at the stern of a ship

Abstract

The present invention relates to the technical field and discloses a method for installing steel castings at the stern of a ship. Multiple positioning processes are performed before welding the front steel casting and the rear steel casting, and supports are provided before welding to ensure that the positions of the front steel casting and the rear steel casting are accurate and can be maintained stable during the welding process. The present application adopts a height benchmark and a dual reference line positioning method to control the deviation between the front steel casting and the rear steel casting within a smaller range, which greatly reduces the positioning error level compared to traditional processes. The support structure during the welding process effectively suppresses the shrinkage deformation caused by welding thermal stress, prevents assembly accumulation caused by welding thermal deformation during the processing process, ensures welding quality, reduces structural strength risks, and avoids chain failures in subsequent processes.

Description

Technical Field

[0001] The present invention relates to the technical field of ship production, in particular to a method for installing a steel casting at the stern of a ship. Background Art

[0002] As a core load-bearing component of the stern structure, the quality of its installation directly impacts the operational stability of the propulsion system and the safety of the hull structure. Traditionally, the tail casting (including the fore and aft castings) must meet the high-precision fit requirements for tail shaft installation. The assembly clearance between the fore and aft castings is typically controlled within ±0.05mm to ensure efficient propeller power transmission and minimize vibration risk. Current construction methods weld the fore and aft castings directly after hoisting. Due to the small clearance between the tail shaft and the tail casting, thermal deformation during welding and cumulative assembly errors can easily cause the tail casting's axis to shift, leading to a failure in the fit between the tail shaft and the casting, abnormal shafting wear, and shafting misalignment. Furthermore, uncontrollable welding deformation poses a risk to structural strength and can easily cause cascading failures in subsequent processes. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for installing steel castings at the stern of a ship, which can prevent assembly accumulation caused by welding thermal deformation during processing, ensure welding quality, reduce structural strength risks, and avoid chain failures in subsequent processes.

[0004] In order to achieve the above object, the present invention provides a method for installing a steel casting at the stern of a ship, comprising the following steps:

[0005] According to the distance between the front steel casting and the rear steel casting, height benchmarks of the front steel casting and the rear steel casting are respectively arranged on the hull slow-loading plate;

[0006] Marking the vertical positioning reference lines of the front steel casting and the rear steel casting on the two height markers respectively, and the horizontal position of the height marker at the rear steel casting serves as the horizontal positioning reference line of the front steel casting and the rear steel casting;

[0007] Hoisting the front steel casting and the rear steel casting, and performing preliminary positioning of the front steel casting and the rear steel casting according to the vertical positioning reference line and the horizontal positioning reference line;

[0008] Determine the center lines of the front steel casting and the rear steel casting, draw a steel wire on the height pole to mark it, fine-tune the position of the steel wire according to the drawing requirements, and further adjust the height positions of the front steel casting and the rear steel casting based on the comparison results of the center lines of the front steel casting and the rear steel casting and the steel wire;

[0009] providing supports for the front steel casting and the rear steel casting;

[0010] The connection between the front steel casting and the rear steel casting is welded, and the support is removed after welding to complete the assembly of the front steel casting and the rear steel casting.

[0011] Compared with the prior art, the installation method of a steel casting at the stern of a ship according to an embodiment of the present invention has the following beneficial effects: multiple positioning processes are performed before welding the front steel casting and the rear steel casting, and supports are provided before welding, so that the positions of the front steel casting and the rear steel casting are accurate and can be maintained stable during the welding process. This application adopts a height benchmark and a dual reference line positioning method to control the deviation between the front steel casting and the rear steel casting within a smaller range, which greatly reduces the positioning error level compared to traditional processes. The support structure during the welding process effectively suppresses the shrinkage deformation caused by welding thermal stress, prevents the assembly accumulation caused by welding thermal deformation during the processing process, ensures welding quality, reduces the risk of structural strength, and avoids chain failures in subsequent processes.

[0012] In the installation method of the steel castings at the stern of a ship according to an embodiment of the present invention, the step of determining the center lines of the front steel casting and the rear steel casting includes: drawing the respective center lines of the front steel casting and the rear steel casting before hoisting, and leveling the respective sections of the front steel casting and the rear steel casting before installation.

[0013] In the installation method of the steel castings at the stern of a ship according to an embodiment of the present invention, before the front steel casting and the rear steel casting are hoisted, installation areas of the hull outer plate structure are left on both sides of the front steel casting and the rear steel casting, and the width of the installation area is greater than 300 mm.

[0014] According to the method for installing the steel castings at the stern of a ship according to an embodiment of the present invention, after the front steel casting and the rear steel casting are welded, the hull structure outer plates arranged on both sides of the front steel casting and the rear steel casting are installed.

[0015] In the installation method of the steel casting at the stern of a ship according to an embodiment of the present invention, a bolt structure is provided at the bottom of the connection between the steel wire and the height benchmark, and a plumb bob is provided at the end of the steel wire.

[0016] The installation method of the steel casting at the stern of a ship in an embodiment of the present invention, in the process of fine-tuning the position of the steel wire according to the requirements of the drawing, includes the following steps: determining the horizontality of the steel wire according to the angle between the steel wire and the plumb line of the plumb bob, and adjusting the bolt structure according to the error of the horizontality to adjust the height of the steel wire at the benchmark.

[0017] According to the installation method of the steel casting at the stern of a ship according to an embodiment of the present invention, during the welding process of the front steel casting and the rear steel casting, the accuracy value between the front steel casting and the rear steel casting is monitored throughout the entire process.

[0018] In the installation method of the steel castings at the stern of a ship according to an embodiment of the present invention, if the precision numerical error during welding is too large, welding is stopped and the welding sequence is adjusted to ensure that the precision of the welding of the front steel casting and the rear steel casting meets the requirements.

[0019] In the installation method of the steel castings at the stern of a ship according to an embodiment of the present invention, during the welding process of the front steel casting and the rear steel casting, the accuracy values ​​of the front steel casting and the rear steel casting are detected by a laser level or an ultrasonic positioning instrument.

[0020] In the installation method of the steel casting at the stern of a ship according to an embodiment of the present invention, after the positioning of the front steel casting is completed, the front steel casting is fixed to the hull slow-installation plate by spot welding.

[0021] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 1 is a schematic diagram of a vertical cross-sectional structure of a method for installing a steel casting at the stern of a ship according to an embodiment of the present invention;

[0023] Figure 2 yes Figure 1 The enlarged schematic diagram of the M in the middle;

[0024] Figure 3 1 is a schematic diagram of a horizontal cross-sectional structure of a method for installing a steel casting at the stern of a ship according to an embodiment of the present invention;

[0025] In the figure, 1. Front steel casting; 2. Rear steel casting; 3. Vertical positioning reference line; 4. Height benchmark; 5. Horizontal positioning reference line; 6. Steel wire; 7. Support; 8. Center line; 9. Hull slow-down plate; 10. Hull structure outer plate; 11. Bolt structure; 12. Plumb bob. DETAILED DESCRIPTION

[0026] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0027] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0028] In the description of the present invention, "several" means one or more, "many" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0029] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0030] like Figure 1 and Figure 3 As shown, a method for installing a steel casting at the stern of a ship according to a preferred embodiment of the present invention comprises the following steps:

[0031] S1: According to the distance between the front steel casting 1 and the rear steel casting 2, height benchmarks 4 of the front steel casting 1 and the rear steel casting 2 are respectively set on the hull slow-loading plate 9;

[0032] S2: Mark the vertical positioning reference lines 3 of the front steel casting 1 and the rear steel casting 2 on two height markers 4 respectively. The horizontal position of the height marker 4 at the rear steel casting 2 serves as the horizontal positioning reference line 5 of the front steel casting 1 and the rear steel casting 2;

[0033] S3: hoist the front steel casting 1 and the rear steel casting 2, and perform preliminary positioning of the front steel casting 1 and the rear steel casting 2 according to the vertical positioning reference line 3 and the horizontal positioning reference line 5;

[0034] S4: Determine the center line 8 of the front steel casting 1 and the rear steel casting 2, draw a steel wire 6 on the height mark 4 to mark it, fine-tune the position of the steel wire 6 according to the drawing requirements, and further adjust the height position of the front steel casting 1 and the rear steel casting 2 based on the comparison result of the center line 8 of the front steel casting 1 and the rear steel casting 2 and the steel wire 6;

[0035] S5: Setting supports 7 at the front steel casting 1 and the rear steel casting 2;

[0036] S6: Weld the connection between the front steel casting 1 and the rear steel casting 2, remove the support 7 after welding, and complete the assembly of the front steel casting 1 and the rear steel casting 2.

[0037] The installation method of the present application performs multiple positioning processes before welding the front steel casting 1 and the rear steel casting 2, and sets a support 7 before welding, so that the position of the front steel casting 1 and the rear steel casting 2 is accurate and can be maintained stable during the welding process. The present application adopts a height benchmark 4 and a dual reference line positioning method to control the deviation between the front steel casting 1 and the rear steel casting 2 within a smaller range, which greatly reduces the positioning error level compared to traditional processes. The support 7 structure during the welding process effectively suppresses the shrinkage deformation caused by welding thermal stress, prevents the assembly accumulation caused by welding thermal deformation during the processing process, ensures welding quality, reduces the risk of structural strength, and avoids chain failures in subsequent processes.

[0038] In some embodiments of the present invention, the step of determining the center line 8 of the front steel casting 1 and the rear steel casting 2 in S4 includes: drawing the center line 8 of each of the front steel casting 1 and the rear steel casting 2 before hoisting, and leveling the sections of each of the front steel casting 1 and the rear steel casting 2 before installation. The center lines 8 of the front steel casting 1 and the rear steel casting 2 are determined before hoisting, and are aligned with each other after hoisting. After alignment, the alignment is compared with the steel wire 6 provided on the height mark 4 to determine the horizontality error, thereby ensuring accurate positioning before welding and guaranteeing the welding quality of the front steel casting 1 and the rear steel casting 2.

[0039] In some embodiments of the present invention, before the front steel casting 1 and the rear steel casting 2 of S3 are hoisted, installation areas for the hull structural outer plate 10 are left on both sides of the front steel casting 1 and the rear steel casting 2, and the width of the installation area is greater than 300 mm. The hull structural outer plate 10 structure forms a continuous watertight barrier through a sealed connection to ensure that the stern area of ​​the hull is watertight during navigation and maintain the overall buoyancy balance of the ship. This is particularly critical for the sealing of the complex structure around the tail steel casting, which can prevent the shafting components from corrosion failure due to seawater intrusion. The structural outer plate can also resist dynamic loads such as wave impact and grounding collision, protecting the tail steel casting and the tail shaft system from direct impact damage. The present application ensures the installation space of the structural outer plate by leaving an installation area between the tail steel casting and the structural outer plate, and prevents installation interference between the structural outer plate and the tail steel casting.

[0040] In some embodiments of the present invention, after the welding of the front steel casting 1 and the rear steel casting 2 is completed in S6, the hull structure outer plates 10 provided on both sides of the front steel casting 1 and the rear steel casting 2 are installed. In the present application, the hull structure outer plates 10 are installed after the welding of the front steel casting 1 and the rear steel casting 2 is completed, so that there is sufficient space for welding the front steel casting 1 and the rear steel casting 2, thereby preventing the welding quality from being affected due to the small operating space during the welding process, and also preventing damage to the hull structure outer plates 10 during the welding process, thereby ensuring the quality of the hull structure outer plates 10 and the welding quality between the front steel casting 1 and the rear steel casting 2.

[0041] like Figure 2 As shown, in some embodiments of the present invention, a bolt structure 11 is provided at the bottom of the connection between the steel wire 6 and the height mark 4, and a plumb bob 12 is provided at the end of the steel wire 6. The bolt structure 11 is used to adjust the height of the steel wire 6. The bolt structure 11 includes a small steel plate abutting the steel wire 6, and the bottom of the small steel plate is connected with a bolt and a nut passing through the screw rod. The adjusting bolt can move the small steel plate toward or away from the steel wire 6 to adjust the height of the steel wire 6; the plumb bob 12 marks the vertical line through the plumb line connected to the steel wire 6, and the angle between it and the steel wire 6 is observed to facilitate determining the horizontality of the steel wire 6.

[0042] In some embodiments of the present invention, in S4, fine-tuning the position of the steel wire 6 according to the drawing requirements includes the following steps: determining the horizontality of the steel wire 6 according to the angle between the steel wire 6 and the plumb line of the plumb bob 12, and adjusting the bolt structure 11 according to the error of the horizontality to adjust the height of the steel wire 6. If the angle is too small, the horizontality of the steel wire 6 is insufficient, and the bolt structure 11 moves upward to lift the steel wire 6 so that the steel wire 6 is horizontal with the center line 8; if the angle is too large, the horizontality of the steel wire 6 is too much, and the bolt structure 11 moves downward to cause the steel wire 6 to move downward under the action of gravity or tension.

[0043] In some embodiments of the present invention, during the welding process of the front steel casting 1 and the rear steel casting 2, the accuracy values ​​between the front steel casting 1 and the rear steel casting 2 are monitored throughout the entire process, and the front steel casting 1 and the rear steel casting 2 are monitored throughout the welding process to ensure the welding quality of the front steel casting 1 and the rear steel casting 2, and the welding can be adjusted during the welding process. By fine-tuning the welding process, the positioning of the front steel casting 1 and the rear steel casting 2 during the welding process is not affected, which ensures that the gap distance between the tail steel casting composed of the front steel casting 1 and the rear steel casting 2 and the tail shaft after welding is not affected, further ensuring the reliability of the tail shaft axis system.

[0044] In some embodiments of the present invention, if the numerical error of the precision during the welding process is too large, the welding is stopped and the welding sequence is adjusted to ensure that the precision of the welding of the front steel casting 1 and the rear steel casting 2 meets the requirements. That is, if a change in levelness or welding precision is detected on one side, the worker or the robotic arm is reminded to weld on the other side to compensate, so that the precision of the welding of the front steel casting 1 and the rear steel casting 2 is guaranteed.

[0045] In some embodiments of the present invention, during the welding process of the front steel casting 1 and the rear steel casting 2, the precision values ​​of the front steel casting 1 and the rear steel casting 2 are detected by a laser level or an ultrasonic locator, and the measurement results are accurate. The laser level or ultrasonic locator is connected to a controller, and data integration and instruction output are realized through the controller. The controller automatically completes the judgment of the precision value, and outputs the control result according to the precision value, instructing the robot arm or the worker to adjust the welding position.

[0046] In some embodiments of the present invention, after the positioning of the front steel casting 1 is completed, the front steel casting 1 is spot-welded to the hull buffer plate 9, so that the front steel casting 1 is pre-firmly fixed on the hull buffer plate 9, providing a positioning fulcrum for the rear steel casting 2, and the overall adjustment of the tail steel casting is achieved by adjusting the rear steel casting 2, so that the overall installation of the tail steel casting is realized in an orderly manner, which is also beneficial to the initial positioning of the front steel casting 1 and the rear steel casting 2.

[0047] The working process of the most embodiment of the present invention is:

[0048] S00: Draw the center lines 8 of the front steel casting 1 and the rear steel casting 2, and level the sections of the front steel casting 1 and the rear steel casting 2 before lifting;

[0049] S01: According to the distance between the front steel casting 1 and the rear steel casting 2, height benchmarks 4 of the front steel casting 1 and the rear steel casting 2 are respectively set on the hull slow-loading plate 9;

[0050] S02: Mark the vertical positioning reference lines 3 of the front steel casting 1 and the rear steel casting 2 on two height markers 4 respectively. The horizontal position of the height marker 4 at the rear steel casting 2 serves as the horizontal positioning reference line 5 of the front steel casting 1 and the rear steel casting 2;

[0051] S03: hoist the front steel casting 1 and the rear steel casting 2, and perform preliminary positioning of the front steel casting 1 and the rear steel casting 2 according to the vertical positioning reference line 3 and the horizontal positioning reference line 5, leaving installation areas for the hull structure outer plate 10 on both sides of the front steel casting 1 and the rear steel casting 2, and the width of the installation area is greater than 300 mm;

[0052] S04: Determine the center line 8 of the front steel casting 1 and the rear steel casting 2, draw a steel wire 6 on the height mark 4 to mark it, determine the horizontality of the steel wire 6 based on the angle between the steel wire 6 and the plumb line, adjust the bolt structure 11 based on the error in the horizontality to adjust the height of the steel wire 6, and further adjust the height position of the front steel casting 1 and the rear steel casting 2 based on the comparison result of the center line 8 of the front steel casting 1 and the rear steel casting 2 and the steel wire 6;

[0053] S05: Install supports 7 at the front steel casting 1 and the rear steel casting 2;

[0054] S06: Weld the connection between the front steel casting 1 and the rear steel casting 2, and monitor the accuracy between the front steel casting 1 and the rear steel casting 2 throughout the process. After welding, remove the support 7 to complete the assembly of the front steel casting 1 and the rear steel casting 2; finally, install the hull structure outer plate 10 set on both sides of the front steel casting 1 and the rear steel casting 2.

[0055] In summary, the embodiments of the present invention provide a method for installing steel castings at the stern of a ship, which can prevent assembly accumulation caused by welding thermal deformation during the processing process, ensure welding quality, reduce structural strength risks, and avoid chain failures in subsequent processes.

[0056] 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 substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A method for installing a steel casting at the stern of a ship, characterized in that: The following steps are involved: According to the distance between the front steel casting and the rear steel casting, height benchmarks of the front steel casting and the rear steel casting are respectively arranged on the hull slow-loading plate; Marking the vertical positioning reference lines of the front steel casting and the rear steel casting on the two height markers respectively, and the horizontal position of the height marker at the rear steel casting serves as the horizontal positioning reference line of the front steel casting and the rear steel casting; Hoisting the front steel casting and the rear steel casting, and performing preliminary positioning of the front steel casting and the rear steel casting according to the vertical positioning reference line and the horizontal positioning reference line; Determine the center lines of the front steel casting and the rear steel casting, draw a steel wire on the height pole to mark it, fine-tune the position of the steel wire according to the drawing requirements, and further adjust the height positions of the front steel casting and the rear steel casting based on the comparison results of the center lines of the front steel casting and the rear steel casting and the steel wire; The step of determining the center lines of the front steel casting and the rear steel casting comprises: drawing the center lines of the front steel casting and the rear steel casting before hoisting, and leveling the sections of the front steel casting and the rear steel casting before installation; Providing supports on the front steel casting and the rear steel casting; The connection between the front steel casting and the rear steel casting is welded, and the support is removed after welding to complete the assembly of the front steel casting and the rear steel casting.

2. The method for installing a steel casting at the stern of a ship according to claim 1, wherein: Before the front steel casting and the rear steel casting are hoisted, installation areas for the hull structure outer plate are reserved on both sides of the front steel casting and the rear steel casting, and the width of the installation area is greater than 300 mm.

3. The method for installing a steel casting at the stern of a ship according to claim 2, wherein: After the front steel casting and the rear steel casting are welded, the hull structure outer plates arranged on both sides of the front steel casting and the rear steel casting are installed.

4. The method for installing a steel casting at the stern of a ship according to claim 1, wherein: A bolt structure is provided at the bottom of the connection between the steel wire and the height benchmark, and a plumb bob is provided at the end of the steel wire.

5. The method for installing a steel casting at the stern of a ship according to claim 4, characterized in that: The process of fine-tuning the position of the steel wire according to the drawing requirements includes the following steps: determining the horizontality of the steel wire according to the angle between the steel wire and the plumb line of the plumb bob, and adjusting the bolt structure according to the error of the horizontality to adjust the height of the steel wire at the height marker.

6. The method for installing a steel casting at the stern of a ship according to claim 1, wherein: During the welding process of the front steel casting and the rear steel casting, the precision values ​​between the front steel casting and the rear steel casting are monitored throughout the entire process.

7. The method for installing a steel casting at the stern of a ship according to claim 6, characterized in that: If the numerical error of the precision during the welding process is too large, the welding is stopped and the welding sequence is adjusted to ensure that the precision of the welding of the front steel casting and the rear steel casting meets the requirements.

8. The method for installing a steel casting at the stern of a ship according to claim 6, wherein: During the welding process of the front steel casting and the rear steel casting, the accuracy values ​​of the front steel casting and the rear steel casting are detected by a laser level or an ultrasonic positioning instrument.

9. The method for installing a steel casting at the stern of a ship according to claim 1, wherein: After the front steel casting is positioned, the front steel casting is fixed to the hull slow-loading plate by spot welding.

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