A non-parallel dual-axis positioning method

Abstract

The present invention discloses a method for positioning non-parallel dual axis lines. S1: using the midship line of the ship's center as the reference line, according to the slope X of the slipway and the distance a between the two ribs, calculate the length b of the hypotenuse of the slipway center line and the height c at the first reference line; S2: calculate the length of the plane axis d on the slipway; S3: calculate the angle Z between the center line of the shaft system and its projection line on the horizontal plane; S4: according to the designed stern tube distance D, calculate the horizontal and vertical coordinates of the first reference point and the tail reference point; S5: and locate the light target positions of the first reference point and the tail reference point. This method can accurately locate the center lines of non-parallel dual axis systems, provide a precise reference for the installation of the shaft system, and provide a guarantee for the high-quality installation of the axis line. After inspection by ship mooring and navigation tests, the shaft system is operating normally. The successful application of this positioning method provides a reference for the subsequent development of the same type or similar work, and improves the construction and quality control of complex shaft systems.

Description

Technical Field

[0001] The present invention relates to the technical field of ship shafting positioning, and in particular to a non-parallel dual-axis positioning method. Background Art

[0002] A ship's shafting system is the collective term for the power transmission components from the output of the main propulsion unit to the propeller. As a vital component of a ship's power plant, the installation and alignment of the shafting system are crucial. Correct installation and alignment procedures ensure that the loads on each shafting bearing are within a reasonable operating range, thus ensuring the shafting system operates in optimal condition.

[0003] Typically, ships are equipped with a single engine and single shaft, though some specialized vessels may also have dual shafts, often at an angle. A ship designed with a non-parallel dual-shaft, dual-propulsion system effectively reduces the impact of currents on the ship's stern structure, resulting in excellent maneuverability, maneuverability, and high propulsion efficiency. However, the alignment of the axes of dual-shaft, dual-rudder vessels with an angled axis is particularly challenging during construction. Furthermore, the horizontal angle of the slipway during construction makes alignment extremely challenging.

[0004] In view of the above, it is necessary to propose a non-parallel dual-axis positioning method to solve the above problems. Summary of the Invention

[0005] The purpose of the present invention is to solve the above technical problems and provide a non-parallel dual-axis positioning method.

[0006] In order to achieve the above object, the present invention adopts the following technical solution: a non-parallel dual-axis positioning method, comprising the following steps:

[0007] S1: With the ship's centerline as the reference line, several ribs are evenly spaced on the amidships line. A forward reference line (first rib) and aft reference line (second rib) are set on the amidships line. Based on the slipway's inclination X and the distance a between the two ribs, the length b of the slipway's centerline hypotenuse and the height c at the forward reference line are calculated.

[0008] S2: Based on the angle Y between the centerline of the ship's designed shafting and the reference line and the length b of the hypotenuse of the slipway centerline, the plane axis d on the slipway and the slipway centerline b form a right triangle. Calculate the length of the plane axis d on the slipway.

[0009] S3: Calculate the angle Z between the axis line of the shaft system and its projection on the horizontal plane based on the length of the axis line d on the slipway obtained in step 2 and the height c of the forward reference line;

[0010] S4: Based on the angle Y between the shafting centerline and the reference line, the angle Z between the shafting centerline and its projection on the horizontal plane, and the designed stern tube distance D, calculate the horizontal and vertical coordinates of the forward and aft reference points.

[0011] S5: Set up a total station at the tail base point according to the horizontal and vertical coordinates obtained in step 4, measure the distance between the first reference point and the tail reference point and the midship, and locate the positions of the light targets of the first reference point and the tail reference point.

[0012] Furthermore, the centerline deviation of the axis system is ±3mm, the dual axis system should have the same trend deviation, and the deviation between the centerline of the dual axis and the theoretical centerline is: ≤4mm.

[0013] Furthermore, the centerline of the dual-axis system is shifted ≤3mm toward the midship or side, and ≤3mm upward or downward.

[0014] Furthermore, the total station illumination positioning method in step 5 includes the following steps:

[0015] S1: Set up a reference total station on the slipway with an inclination, generate a ray parallel to the horizontal through the total station telescope, and transfer the theoretical reference point to the reference target frame set at the stern according to the midship line of the slipway and the vertical measurement design theoretical value to generate the stern reference point;

[0016] S2: Set up a horizontal work platform on the side of the stern reference point away from the stern, and adjust the three-dimensional spatial position of the centering total station on the horizontal work platform. First, adjust the level of the centering total station to the correct level, and then adjust the left and right position of the centering total station according to the distance between the stern reference point and the midship.

[0017] S3: Make the total station's vertical laser beam perpendicular to the horizontal plane; adjust the vertical angle of the centering total station lens so that its angle reading is consistent with the calculated value Z of the axis center line; make the center of the laser beam it emits just pass through the set tail reference point, and generate a centering total station laser beam ray that coincides with the theoretical axis center line.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. This method can be used to accurately locate the center lines of non-parallel dual-axis systems, provide an accurate benchmark for the installation of the shaft system, and ensure the high-quality installation of the axis. After inspection during ship mooring and navigation tests, the shaft system operates normally and the errors are controlled within the design range.

[0020] 2. The successful application of this positioning method provides a reference for subsequent similar or similar work, and improves the design, construction and quality control capabilities of complex shafting.

[0021] 3. The split method can utilize the high precision of the total station to illuminate and center the center line of the ship's shafting. The method is convenient and is especially suitable for illuminating and centering the ship's axis with an angle and on a slipway with an inclination. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the centerline and dual axis lines of the slipway of the present invention and their projections;

[0023] Figure 2 This is a schematic diagram of the centerline of the slipway and the single axis and their projections of the present invention;

[0024] Figure 3 Schematic diagram for calculating the angle between the center line of the shaft system and its projection on the horizontal plane in the present invention;

[0025] Figure 4 Schematic diagram of the conversion of the included angle of the dual-axis system into the horizontal spacing between the fore and aft ribs;

[0026] Figure 5 A schematic diagram of the present invention for determining the centering ray of a total station telescope;

[0027] Figure 6 This is a reference point positioning height positioning diagram in an embodiment of the present invention;

[0028] In the figure: 1. amidships line; 2. Forward datum line; 3. Aft datum line; 4. Ray 1; 5. Datum target mount; 6. Forward datum point; 7. Aft datum point; 8. Working platform; 9. Datum total station; 10. Centering total station; 11. Ray 2. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0030] A non-parallel dual-axis positioning method comprises the following steps:

[0031] S1: With the ship's centerline 1 as the reference line, several ribs are evenly spaced on the amidships line 1. A forward reference line 2 (first rib) and aft reference line 3 (second rib) are set on the amidships line 1. Based on the slipway's inclination X and the distance a between the two ribs, the length b of the slipway's centerline hypotenuse and the height c of the forward reference line 2 are calculated.

[0032] S2: Based on the angle Y between the centerline of the ship's designed shafting and the reference line and the length b of the hypotenuse of the slipway centerline, the plane axis d on the slipway and the slipway centerline b form a right triangle. Calculate the length of the plane axis d on the slipway.

[0033] S3: Calculate the angle Z between the axis line of the shaft system and its projection on the horizontal plane based on the length of the axis line d on the slipway obtained in step 2 and the height c of the forward datum line 2;

[0034] S4: Based on the angle Y between the shafting centerline and the reference line, the angle Z between the shafting centerline and its projection on the horizontal plane, and the designed stern tube distance D, calculate the abscissa and ordinate of the forward reference point 6 and the aft reference point 7;

[0035] S5: Set up a total station at the tail base point according to the horizontal and vertical coordinates obtained in step 4, measure the distance between the first reference point 6 and the tail reference point 7 and the midship, and locate the light target positions of the first reference point 6 and the tail reference point 7.

[0036] The center line deviation of the shaft system is ±3mm, the double shaft system should have the same trend deviation, and the deviation between the center line of the double shaft line and the theoretical center line is: ≤4mm.

[0037] The centerline of the dual-axis system shall be shifted ≤3mm toward the midship or side, and ≤3mm upward or downward.

[0038] The total station illumination positioning method in step 5 above includes the following steps:

[0039] S1: A reference total station 9 is set up on the inclined slipway surface. A ray parallel to the horizontal is generated through the total station telescope. Based on the midship line 1 of the slipway surface and the vertical measurement, the theoretical reference point is transferred to the reference target frame 5 located at the stern to generate the stern reference point 7.

[0040] S2: Set up a horizontal work platform 8 on the side of the stern reference point 7 away from the stern, and adjust the three-dimensional spatial position of the centering total station 10 on the horizontal work platform 8. First, adjust the level of the centering total station 10 to the correct level, and then adjust the left and right position of the centering total station 10 according to the distance between the stern reference point 7 and the midship.

[0041] S3: Make the total station's vertical laser beam perpendicular to the horizontal plane; adjust the vertical angle of the centering total station 10 lens so that its angle reading is consistent with the calculated value Z of the axis center line; make the center of the laser beam it emits just pass through the set tail reference point 7, and generate a centering total station 10 laser beam ray that coincides with the theoretical axis center line. Example

[0042] During the implementation of this embodiment, under the on-site construction conditions of the ship, in order to meet the positioning requirements, we selected two total stations, and used the same reference and simultaneous positioning method on the left and right sides to reduce the deviation generated during the process.

[0043] like Figure 5As shown, a reference total station 9 is set up to establish a horizontal reference line with ray 1 as the reference. During the construction process, the double axis is controlled with reference to the midship line 1 to ensure that the segment accuracy meets the standard. Figure 4 As shown in the figure, after the shafting is completed, the shafting projection line can be drawn to the inner bottom of the segment, the bow bulkhead, and the tail shaft outlet. Figure 6 As shown, the distance between the center of the propeller hub of the two shaft systems and the horizontal machine reference line is measured to be 26000mm. According to the design, the angle between the two axes and the midship line 1 is 3°, and the distance D between the center of the propeller hub and the midship line 1 is 5940mm. In this embodiment, the inclination of the slipway is 1:20 (that is, the angle between the inclined surface of the slipway and the horizontal plane is 2.8624°); Figure 1 As shown, C P is the centerline of the port shaft system, C S The starboard shaft centerline is the included angle between the starboard shaft centerline and the horizontal plane as shown in the figure. The same reference is used to locate the two shaft centerlines. Figure 2 The figure shows the structural relationship formed by the parallel lines between the centerline of the shafting on one side and the centerline of the slipway;

[0044] like Figure 3 As shown in (1), the right triangle formed by OB-B' is a plane parallel to the vertical plane where the midship line 1 is located. Point O is the stern reference point 7, which coincides with the center line of the shaft system. The slope X of the slipway is 1:20 (that is, the angle between the slipway slope and the horizontal plane is 2.8624°). According to the design drawing, a is 20000mm and c is 1000mm. According to the Pythagorean theorem, the length of b can be calculated to be 20024.98mm, which is Figure 2 Length of the middle OB;

[0045] according to Figure 2 In the figure, the right triangle formed by OBA is Figure 3 As shown in (2), the length of b is 20024.98 mm, Y is the angle 3° between the centerline of the shafting system of the ship and the midship line 1, and according to the Pythagorean theorem, the length d of OA can be calculated to be 20052.47 mm; and the length of AB is 1049.46 mm;

[0046] like Figure 2 The OA-A' formed in the equation is a right triangle formed by the axis centerline and its projection on the horizontal plane, specifically: Figure 3 As shown in (3), based on the length of d and the known height of c, the angle Z between the center line of the shaft system and its projection line on the horizontal plane can be calculated as 2.8585° according to the Pythagorean theorem, and the distance from the tail datum point 7 to the midship is calculated to be 5670mm, and the distance from the forward datum point 6 to the midship is calculated to be 6606mm. The data obtained from the above calculations provide positioning data for the subsequent field use of the total station to perform shaft system positioning at the tail datum point 7;

[0047] like Figure 4 、 Figure 5 In the process, a reference total station 9 is set on the ground of the slipway. A ray 4 parallel to the horizontal plane is generated by the telescope of the reference total station 9, which is used as a horizontal reference plane. The theoretically calculated tail reference point 7 is transferred to the reference target frame 5 set at the tail to generate the tail reference point 7;

[0048] A horizontal work platform 8 is made on the reference target frame 5 for setting up a centering total station 10; the three-dimensional spatial position of the centering total station 10 located on the horizontal work platform 8 is adjusted so that the laser beam of the centering total station 10 passes through the tail reference point 7 to generate a centering total station 10 laser beam ray 11 that coincides with the center line of the theoretical axis system;

[0049] Specifically, first adjust the centering total station 10 to the right level, and then adjust the height of the centering total station 10 to Figure 6 As shown, the left and right positions are as follows Figure 4 As shown, adjust the vertical angle of the lens of the centering total station 10 so that its angle reading is consistent with the angle Z value between the center line of the axis system and its projection line on the horizontal plane obtained by the above calculation. Finally, adjust the horizontal angle of the head of the centering total station 10 as a whole, that is, the angle Y between the designed center line of the axis system and the reference line is 3°, so that the center of the laser beam emitted by it just passes through the set tail reference point 7, and generates the centering total station 10 laser ray 2 11 that coincides with the center line of the theoretical axis.

[0050] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A non-parallel dual-axis positioning method, characterized in that: The following steps are involved: S1: With the midship line (1) at the center of the ship as the reference line, a number of ribs are evenly spaced on the midship line (1), and a forward reference line (2) and aft reference line (3) are set on the midship line (1). Based on the slope X of the slipway and the distance a between the two ribs, the length b of the oblique side of the slipway centerline and the height c at the forward reference line (2) are calculated; S2: Based on the angle Y between the centerline of the shafting system of the ship and the reference line and the length b of the hypotenuse of the slipway centerline, the plane axis d on the slipway and the slipway centerline b form a right triangle. The length of the plane axis d on the slipway is calculated. The plane axis d is located on the centerline of the shafting system. S3: Based on the length of the axis d of the slipway plane obtained in step 2 and the height c of the fore datum line (2), calculate the angle Z between the center line of the shafting and its projection line on the horizontal plane; S4: Based on the angle Y between the shafting centerline and the reference line and the angle Z between the shafting centerline and its projection on the horizontal plane, and the designed stern tube distance D, calculate the horizontal and vertical coordinates of the forward reference point (6) and the aft reference point (7); S5: According to the horizontal coordinates and vertical coordinates obtained in step 4, a total station is set up at the tail reference point (7), and the distances from the first reference point (6) and the tail reference point (7) to the midship are measured, and the positions of the light targets of the first reference point (6) and the tail reference point (7) are located.

2. A non-parallel dual-axis positioning method according to claim 1, characterized in that: The center line deviation of the shaft system is ±3mm, the double shaft system should have the same trend deviation, and the deviation between the center line of the double shaft line and the theoretical center line is: ≤4mm.

3. The non-parallel dual-axis positioning method according to claim 1, characterized in that: The centerline of the dual-axis system shall be shifted ≤3mm toward the midship or side, and ≤3mm upward or downward.

4. The non-parallel dual-axis positioning method according to claim 1, characterized in that: The total station illumination positioning method in step 5 includes the following steps: S1: A reference total station (9) is set up on the slipway ground with an inclination angle, and a ray (4) parallel to the horizontal plane is generated through the total station telescope. According to the midship line (1) of the slipway ground and the design theoretical value of vertical measurement, the theoretical reference point is transferred to the reference target frame (5) set at the stern to generate the stern reference point (7); S2: Set up a horizontal working platform (8) on the side of the stern reference point (7) away from the stern, and adjust the three-dimensional spatial position of the centering total station (10) located on the horizontal working platform (8). First, adjust the level of the centering total station (10) to the right position, and then adjust the left and right positions of the centering total station (10) according to the distance from the stern reference point (7) to the midship. S3: Make the total station vertical laser beam perpendicular to the horizontal plane; adjust the vertical angle of the centering total station (10) lens so that its angle reading is consistent with the calculated value Z of the axis center line; make the center of the laser beam emitted by it just pass through the set tail reference point (7), and generate the centering total station (10) laser beam ray coinciding with the theoretical axis center line.

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