A method for controlling the precision of segmented positioning of shafting

Abstract

A method for controlling the positioning accuracy of a shafting segment, wherein the reference segment is located in a dock room, a stern reference point is drawn on the dock wall, and a bow reference point is drawn on the reference segment, and a total station is used to establish the bow reference point and the stern reference point to form a three-dimensional coordinate system, and the line data of the bow reference point and the stern reference point are obtained at the same time. The shafting segment is docked with the reference segment, and a stern tube is provided above the shafting segment. A plurality of reflective light targets are respectively arranged at the bow end and the stern end of the stern tube. The three-dimensional coordinates of the center points of the bow end and the stern end of the stern tube are measured by a total station, and then the line data of the bow end and the stern end of the stern tube are obtained. The line data of the bow reference point and the stern reference point are calculated, and the deviation value of the line data of the bow end and the stern end of the stern tube is calculated to ensure that the deviation value is within the maximum value range that can be bored. The present invention can quickly determine the deviation direction and trend of the shafting segment boring, improve the positioning accuracy of the shafting segment on site, reduce subsequent correction work, and reduce construction costs.

Description

Technical Field

[0001] The present invention relates to positioning of shafting segments during shipbuilding, accurately and quickly determining the deviation direction and trend of shafting segment boring, and obtaining the corresponding precision data of shafting segment boring at one time, so as to improve the positioning accuracy of shafting segments, facilitate the positioning construction of shafting segments, reduce the subsequent boring correction work, reduce the construction cost, and shorten the construction period. Background Art

[0002] There is a stern tube above the shafting segment. The stern tube is columnar and has a very thin through hole (basically negligible) at the center axis of the stern tube. When the shipyard builds the ship, the stern tube needs to be bored after the shafting segment is positioned, and a boring hole is formed after boring. The boring hole formed after the stern tube with the shafting segment is bored must meet higher tolerance requirements to ensure that the stern shaft can pass through the boring hole, and in the subsequent assembly process, the matching requirements of the shaft and rudder system lighting data are extremely strict. The cross data of the shafting and rudder system needs to be controlled within the range of 2mm. With the in-depth development of the specification, the shipowner's requirements for the deviation of the boring hole data are also more stringent, and the future construction trend is to carry out boring construction in advance. If the shafting segment is not positioned accurately, resulting in the subsequent stern tube being unable to be bored to the required size, the welded shafting segment needs to be cut and separated from the reference segment, and the shafting segment needs to be repositioned and welded so that the stern tube can be bored to the required size to ensure that the stern shaft can pass through the stern tube. Inaccurate positioning may result in multiple reworks, wasting a lot of manpower and material resources.

[0003] Therefore, it is necessary to take necessary measures to improve the data accuracy during the positioning of the shafting segments, so as to ensure that after the ship power unit is positioned, the stern shaft can smoothly pass through the stern tube shaft hole (boring hole) of the shafting segment. The current measuring device has poor measurement effect, and the measurement point accuracy does not meet the requirements; the plumb line method is backward, has strict weather requirements, and has poor accuracy. The simple transverse angle steel device welded on the edge of the stern tube shaft hole (boring hole) is easy to damage the parent material when the transverse angle steel device is cut later, which increases the amount of modification in the later stage. In addition, the instrument needs to be moved repeatedly during the construction process, and the data changes need to be checked repeatedly, resulting in the inability to obtain all the accuracy data at one time, increasing the construction cost and extending the construction period. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a method for controlling the positioning accuracy of shafting segments, which aims to achieve the purpose that after the shafting segments are docked with the reference segments, the stern tubes of the shafting segments can be bored to the maximum value, avoiding the need for subsequent cutting and re-docking. The technical solution adopted is:

[0005] A method for controlling the segment positioning accuracy of a shaft system, wherein a reference segment is located in a dock room, a stern reference point is drawn on a dock wall, and a bow reference point is drawn on the reference segment, both the stern reference point and the bow reference point are located on a theoretical longitudinal center line of a hull, and the height of the bow reference point = the height of an upper plate surface of a main engine pit + a theoretical height of an upper plate surface of a main engine pit from a center point of a stern axis; the height of the stern reference point = an average value of a baseline height + a thickness of an outer bottom plate of a hull + a height value of a center of a theoretical axis from an upper plate surface of an outer bottom plate of a hull, a total station is used to establish a station for the bow reference point and the stern reference point to form a three-dimensional coordinate system, and simultaneously obtains data of a line connecting the bow reference point and the stern reference point.

[0006] The shafting segment is docked with the reference segment. A stern tube is mounted above the shafting segment. Multiple reflective light targets are respectively set at the bow end and the stern end of the stern tube. The three-dimensional coordinates of the center points of the bow end and the stern end of the stern tube are measured by a total station, and then the connection data between the bow end and the stern end of the stern tube are obtained.

[0007] Calculate the deviation between the data of the line connecting the bow reference point and the stern reference point and the data of the line connecting the bow end and the stern end of the stern tube, and determine whether the deviation is within the maximum value range that can be bored of the stern tube. If so, seal the shafting segment and the reference segment, and fix them by welding after sealing.

[0008] If the deviation value exceeds the maximum range that can be bored, the shaft system needs to be repositioned in sections and the above steps repeated until the deviation value is within the maximum range that can be bored.

[0009] In the above-mentioned method for controlling the segmented positioning accuracy of a shaft system, further, a plurality of reflection light targets are arranged at equal intervals along the circumference of the bow end of the stern tube, and a plurality of reflection light targets are arranged at equal intervals along the circumference of the stern end of the stern tube.

[0010] The above-mentioned method for controlling the positioning accuracy of a shafting segment further comprises the following steps: the shafting segment is hoisted into the dock and docked with the reference segment.

[0011] The above-mentioned method for controlling the positioning accuracy of shaft system segments further includes: after the shaft system segments and the reference segments are sealed, the shaft system segments and the reference segments are re-inspected, and after the re-inspection is qualified, the shaft system segments and the reference segments are welded and fixed.

[0012] In the above-mentioned method for controlling the segment positioning accuracy of a shaft system, further, a bracket is provided at the reference segment away from the bow end of the stern tube, and a bow reference point is drawn on the bracket.

[0013] In the above-mentioned method for controlling the segmented positioning accuracy of a shaft system, further, the reflecting light target is fixed on the inner tube wall of the bow end of the stern tube or the stern end of the stern tube.

[0014] The method adopted by the present invention can quickly determine the deviation direction and trend of the shaft segment boring when the shaft segment is fixed with the reference segment, improve the positioning accuracy of the shaft segment on site, reduce the workload of subsequent correction caused by the accuracy deviation, and greatly reduce the construction cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structure of the present invention;

[0016] Figure 2 It is a schematic diagram of the structure of the bow end of the stern tube or the stern end of the stern tube with a reflective light target;

[0017] Among them: 1-shafting section, 2-reference section, 3-stern tube, 4-stern tube bow end, 5-stern tube stern end, 6-bracket, 7-dock wall, 8-total station, 9-reflective light target, A-stern reference point, B-bow reference point. DETAILED DESCRIPTION

[0018] Example 1

[0019] The present invention will be further described in conjunction with the accompanying drawings.

[0020] like Figure 1 As shown, a method for controlling the accuracy of segmented positioning of a shaft system is provided. The reference segment is located in the dock room, and a main engine pit (not indicated in the figure) is provided on the reference segment. Before the segmented positioning of the shaft system is constructed, the bow reference point and the stern reference point must be set first. Both the bow reference point and the stern reference point are located on the center line of the hull. It is not enough to only determine that the bow reference point and the stern reference point are located on the center line of the hull. It is necessary to further determine the height position of the bow reference point and the stern reference point to ensure the convenience of subsequent positioning of the stern tube. The height value of the bow reference point = the height of the upper plate surface of the main engine pit + the theoretical height of the upper plate surface of the main engine pit from the center point of the stern axis, and the height value of the stern reference point = the average value of the baseline height + the thickness of the outer bottom plate of the hull + the height value of the center of the theoretical axis from the upper plate surface of the outer bottom plate of the hull, and the connection data of the bow reference point and the stern reference point are obtained at the same time. The height of the center of the theoretical axis from the upper surface of the hull's outer bottom plate is a dimension marked on the drawing. The drawing for installing the shafting system will not mark how high it is from the baseline, but only how high it is from the upper surface of the hull's outer bottom plate.

[0021] The horizontal data of the hull outer bottom baseline is measured by using a level meter, and the average value of all the measured data is calculated. According to the calculated baseline average data, the stern reference point is drawn on the dock wall using a laser total station.

[0022] Use the total station to measure the horizontality of the bow reference point and the stern reference point that have been set, and check whether the horizontal height data of the two points are consistent. When the horizontal height data measurement data of the two points deviate, the bow reference point should be used as the main basis to adjust the height direction of the stern reference point, and the actual deviation data of the outer bottom baseline average value should be considered. During the adjustment process, the height data adjustment range of the stern reference point should not exceed 2-4mm. The height of the stern reference point should be consistent with that of the bow reference point. If it is inconsistent, it means that the height measurement of the bow reference point or the stern reference point may be wrong, and the bow reference point and the stern reference point need to be remeasured. In the process of measuring the stern reference point, the baseline average value data only needs to measure the outer bottom reference horizontal data of the shafting segment area. Therefore, using two different calculation formulas to calculate the bow reference point and the stern reference point can play a role in verifying the height data of the two.

[0023] After the bow reference point and the stern reference point are drawn, the shafting section is hoisted into the dock room and positioned and docked with the reference section. The total station is set up on the platform at the stern of the main engine pit of the reference section (the end of the reference section close to the shafting section is the stern). The bow reference point and the stern reference point are established in three dimensions using the total station, and multiple reflective targets are set at equal intervals at the bow end and the stern end of the stern tube of the shafting section, such as Figure 2 As shown, the multiple reflective targets are more than three reflective targets. Only by using more than three reflective targets can the three-dimensional coordinate data of the bow end of the stern tube and the center point of the stern end of the stern tube (i.e., the end circle center) be measured, and the line data of the center point of the bow end of the stern tube and the center point of the stern end of the stern tube can be obtained. The connection data of the center point of the bow end of the stern tube and the center point of the stern end of the stern tube are compared with the line data of the bow reference point and the stern reference point to obtain the deviation value, and it is judged whether the deviation value is within the maximum value range (Y value and Z value) of the stern tube that can be bored, that is, whether this deviation value has an impact on the stern tube being bored to the maximum value. If it has an impact, the shafting segment state is corrected according to the data deviation value until the data meets the requirement that the stern tube can be bored to the maximum value, and finally the positioning data of the shafting segment is determined, and then the positioning and sealing construction of the shafting segment is carried out.

[0024] After the shafting segments are closed, positioned and sealed, the data of the shafting segment bow and stern boring holes and the data of the line connecting the bow reference point and the stern reference point are rechecked, that is, whether the line connecting the bow reference point and the stern reference point coincides with the connection between the bow end of the stern tube and the stern end of the stern tube. As mentioned above, the line connecting the bow reference point and the stern reference point is measured, and the line connecting the bow end of the stern tube and the stern end of the stern tube is measured, and the deviation value between the two is obtained. If the deviation values ​​of the two meet the requirements, the positioning of the shafting segment is completed, and the shafting segment is welded to the reference segment. If the deviation of the two data exceeds the requirements, it is necessary to open the sealing of the shafting segment and the reference segment, re-measure and adjust until the deviation of the two data meets the requirements after sealing.

[0025] The method adopted by the present invention can quickly determine the deviation direction and trend of the shaft segment boring when the shaft segment is fixed with the reference segment, improve the positioning accuracy of the shaft segment on site, reduce the workload of subsequent correction caused by the accuracy deviation, and greatly reduce the construction cost.

Claims

1. A method for controlling the segmented positioning accuracy of an axis system. Features: The reference section is located in the dock room, the stern reference point is drawn on the dock wall, and the bow reference point is drawn on the reference section. The stern reference point and the bow reference point are both located on the theoretical longitudinal center line of the hull, and the height of the bow reference point = the height of the upper plate surface of the main engine pit + the theoretical height of the upper plate surface of the main engine pit from the center point of the stern axis; the height of the stern reference point = the average value of the baseline height + the thickness of the outer bottom plate of the hull + the height value of the center of the theoretical axis from the upper plate surface of the outer bottom plate of the hull. The bow reference point and the stern reference point are established using a total station to form a three-dimensional coordinate system, and the data of the connection line between the bow reference point and the stern reference point are obtained at the same time; The shafting segment is docked with the reference segment. A stern tube is provided above the shafting segment. A plurality of reflective light targets are respectively arranged at the bow end and the stern end of the stern tube. The three-dimensional coordinates of the center points of the bow end and the stern end of the stern tube are measured by a total station, and then the connection line data between the bow end and the stern end of the stern tube are obtained. Calculate the deviation between the data of the line connecting the bow reference point and the stern reference point and the data of the line connecting the bow end and the stern end of the stern tube, and judge whether the deviation is within the maximum value range of the stern tube that can be bored. If it is within the maximum value range that can be bored, seal the shafting segment and the reference segment, and then weld and fix them; If the deviation value exceeds the maximum value range that can be bored, it is necessary to reposition the shaft system in sections, and repeatedly use the total station to measure the three-dimensional coordinates of the center points of the bow end and stern end of the stern tube, and then obtain the line data between the bow end and stern end of the stern tube, calculate the deviation value of the line data between the bow reference point and the stern reference point, and the line data between the bow end and the stern end of the stern tube, until the deviation value is within the maximum value range that can be bored.

2. A method for controlling the segmented positioning accuracy of a shaft system according to claim 1, Features: A plurality of reflection light targets are arranged at equal intervals along the circumference of the bow end of the stern tube, and a plurality of reflection light targets are arranged at equal intervals along the circumference of the stern end of the stern tube.

3. A method for controlling the segmented positioning accuracy of a shaft system according to claim 1, Features: The shaft system segments were hoisted into the dock and docked with the reference segments.

4. A method for controlling the segmented positioning accuracy of a shaft system according to claim 1, Features: After the shafting segments and the reference segments are sealed, they are re-inspected. After passing the re-inspection, the shafting segments and the reference segments are welded and fixed.

5. A method for controlling the segmented positioning accuracy of a shaft system according to claim 1, Features: A bracket is provided at the reference section away from the bow end of the stern tube, and a bow reference point is drawn on the bracket.

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