A curved panel unit and its manufacturing method

Abstract

This invention provides a curved panel unit and its manufacturing method, belonging to the field of bridge engineering construction technology. It solves the problem of inconsistent control points and uneven arc shapes in traditional curved web panel manufacturing, requiring repeated adjustments. The technical solution includes a curved web panel jig, comprising a base jig, vertical support groups on the base jig, and diagonal braces; both ends of the diagonal braces are connected to a fixed ruler and a detachable ruler, respectively. The beneficial effects of this invention are: by checking the fit between the component and the jig's lifting point using the curved web panel jig, precise control of the arc linearity before and after web panel unit manufacturing is achieved; arranging the lifting point and the forming data monitoring point in the same location effectively ensures the overall linearity of the beam segment after assembly; the curved web panel jig allows for arbitrary adjustment of the support point height according to the curvature of the web panel using adjusting bolts and locking nuts.

Description

Technical Field

[0001] This invention relates to the field of bridge engineering construction technology, and in particular to a curved panel unit and its manufacturing method. Background Technology

[0002] The development of urban ramp trough beams and widening / realignment projects is rapid, large-scale, numerous, and complex in alignment. The webs on both sides of these trough beams often employ curved plates, with profiles and diaphragms used for reinforcement within the trough. To control the assembly gaps of the internal supporting profiles and diaphragms and ensure aesthetically pleasing component forming, as well as the precise installation of the internal supporting angle steel and diaphragms, the alignment of the webs on both sides needs precise control to guarantee a smooth curved shape. Traditionally, the top and bottom edges of the web units are used as control points for the curved shape during fabrication, but these control points are not parallel. This results in inconsistent concave and convex arcs in the fabricated plate units, requiring repeated adjustments and impacting construction efficiency.

[0003] How to solve the above-mentioned technical problems is the challenge facing this invention. Summary of the Invention

[0004] The purpose of this invention is to provide a curved panel unit and its manufacturing method, which solves the problem that the control points are not parallel to each other when manufacturing traditional curved webs, and the concave and convex arcs of the panel unit are inconsistent after manufacturing, requiring repeated adjustments.

[0005] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: a curved panel unit, including a web arc-shaped frame, wherein the web arc-shaped frame includes a base frame and a vertical support group and a diagonal brace disposed on the base frame;

[0006] The vertical support group includes vertical support one, vertical support two, vertical support three, and vertical support four;

[0007] The two ends of the diagonal brace are respectively connected to a fixed ruler and a detachable ruler, and a ruler connecting plate is provided in the middle of one end of the diagonal brace.

[0008] The horizontal angle of the diagonal brace is basically consistent with the inclination angle of the web.

[0009] The diagonal cross brace is provided with several evenly distributed adjusting nuts, locking nuts and adjusting bolts; the first adjusting nut and locking nut is 150mm away from the end of the diagonal cross brace, and the remaining adjusting nuts and locking nuts are arranged vertically on the upper part of the diagonal cross brace at intervals of 1000mm.

[0010] Adjusting bolts are vertically installed on the upper part of the diagonal cross brace every 1m / step via adjusting nuts and locking nuts;

[0011] The fixed ruler is perpendicular to the diagonal brace; the detachable ruler is perpendicular to the diagonal brace and is connected to the diagonal brace via a ruler mounting positioning pin; the bottom of the detachable ruler is equipped with a ruler mounting reference seat.

[0012] The basic frame is equipped with stiffening plates inside, and a counterweight block is installed on the top of the stiffening plate. One side of the stiffening plate is connected to the top plate.

[0013] A method for fabricating a curved panel unit includes the following steps:

[0014] Step 1, Design of Curve Control Transformation:

[0015] Based on the linear data of the web, a 3D model is created using software, and a unified reference coordinate system for the web is established with the center of the beam segment for easy control and manufacturing. 3D coordinate data of the intersection of the corresponding transverse reference line and the 2m data line are provided every 2m interval. The middle section is optimized into a straight line for easy control. Within the range of 8 to 50mm in plate thickness, the arc shape can be achieved by using self-weight and additional pressure, supplemented by fire correction.

[0016] Step 2, Fabrication of the web-shaped arc frame:

[0017] The structural foundation frame is set horizontally on the ground; vertical supports one, two, three and four are arranged vertically on the foundation frame from left to right and are aligned with the internal stiffeners of the foundation frame. When the height of vertical supports one, two, three and four is greater than 500mm, a horizontal crossbar is set in the middle of the vertical support group.

[0018] The diagonal brace is connected to vertical support one, vertical support two, vertical support three, and vertical support four;

[0019] A fixed ruler is located at the end of the diagonal brace; a ruler connecting plate is located in the middle of the diagonal brace; a detachable ruler is located at the end of the diagonal brace.

[0020] The above-mentioned symmetrical fabrication of the arc-shaped web frame improves the fabrication efficiency of the web.

[0021] Step 3: Adjust the support height of the web-shaped arc-shaped frame:

[0022] Adjust the web arc-shaped frame data according to the marked point data, use a total station to fine-tune the height of the adjusting bolts, and adjust the inspection lines on the locking nut and adjusting bolts to the same straight line to form an arc-shaped frame;

[0023] Step 4, Web plate hoisting:

[0024] The web plate is placed on the web plate arc-shaped jig with the height adjusted. Through the self-weight of the steel and the curvature formed by the web plate arc-shaped jig, when the steel cannot fit tightly with the support point of the arc-shaped jig, counterweights or heat correction are used to make the material fit tightly with the jig lifting point. After the web plate is formed, reinforcement is added and installed to ensure the arc shape.

[0025] Step 5, Install longitudinal and transverse stiffening plates:

[0026] Install the stiffening plates in sequence, using weight blocks to weigh them down during installation to prevent the web plate from arching after welding heat. After the components are installed, check the fit between the web plate components and the jacking point. If the requirements are not met, make adjustments by fire correction.

[0027] Step Six, Top Plate Installation:

[0028] When installing the top plate, check the fit gap between the top plate and the stiffening plate. The gap should be ≤1mm. Use the top plate angle template and the fit with the stiffening plate to check the angle between the web plate and the top plate.

[0029] When making an angle template, the angle information needs to be transferred from the template surface to the tooling surface.

[0030] Step 7, Web plate hoisting:

[0031] Using specialized hoisting tools, the web plate unit is moved away from the web plate arc-shaped jig and rotated 90° to enter the installation state.

[0032] The basic frame is horizontally positioned on the ground.

[0033] The vertical supports one, two, three, and four are arranged vertically on the foundation frame in sequence and are aligned with the internal reinforcing plates of the foundation frame.

[0034] The diagonal brace is connected to the top of the vertical support assembly;

[0035] The two ends of the diagonal brace extend beyond the connection points of the first and fourth vertical supports, respectively. A detachable scale is installed between the first vertical support and the end of the diagonal brace, and a fixed scale is installed between the fourth vertical support and the end of the diagonal brace. The end of the diagonal brace extends approximately 100mm beyond the first and fourth vertical supports.

[0036] When adjusting the height using the adjusting nut, locking nut, and adjusting bolt, an auxiliary elevation line is drawn using the scale lines on both sides. When the adjusting bolt coincides with the auxiliary elevation line, the locking nut can be used to lock and position it, making it convenient to adjust the linear elevation.

[0037] When the fixed scale and detachable scale are connected to the diagonal brace, the "zero" mark is aligned with the diagonal brace to facilitate accurate reading.

[0038] The detachable ruler and the diagonal brace are connected by a ruler connecting plate and a ruler mounting positioning pin, which facilitates the installation and removal of the detachable ruler. If bolts are used for installation, gaps will be generated.

[0039] The contact surface between the scale mounting base and the detachable scale needs to be milled to ensure that the flatness meets the requirement of 1mm / m, so as to facilitate the reinstallation of the detachable scale after removal.

[0040] The ends of the locking nut bolts need to be ground to avoid damaging the base material.

[0041] Compared with the prior art, the beneficial effects of the present invention are as follows: The curved panel unit manufacturing method provided by this solution checks the fit between the component and the lifting point of the jig using the curved web jig, thereby achieving precise control of the arc linearity before and after the web unit manufacturing; arranging the lifting point and the forming data monitoring point in the same position can effectively ensure the overall linearity data of the beam segment after assembly; the curved web jig can adjust the height of the support point arbitrarily according to the curvature of the web using adjusting bolts and locking nuts; the number of vertical supports and the length of the horizontal supports can be increased or decreased according to the size of the component to meet the manufacturing needs of components of different specifications; this curved web jig enables the panel unit manufacturing and flame calibration to be carried out in the same workstation, which is highly efficient and saves space resources; precise control of the arc linearity can be achieved through a simple flame calibration process; the detachable scale can be quickly and accurately reset and installed by using the scale installation positioning pin and scale installation reference seat. Attached Figure Description

[0042] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0043] Figure 1 A coordinate system side view of the web plate is prepared for an embodiment of the present invention.

[0044] Figure 2 A coordinate system front view is created for the web plate in an embodiment of the present invention.

[0045] Figure 3 This is a schematic diagram of the flatness control area for the support pad installation in an embodiment of the present invention.

[0046] Figure 4 This is a schematic diagram showing the marking of the allowance of the bottom support pad in an embodiment of the present invention.

[0047] Figure 5 for Figure 3 Part I enlarged view.

[0048] Figure 6 for Figure 3 Part II enlarged view.

[0049] Figure 7 for Figure 3 A magnified view of part III.

[0050] Figure 8 This is a schematic diagram of the installation of the web plate mechanism according to an embodiment of the present invention.

[0051] Figure 9 This is a schematic diagram of the top plate angle inspection according to an embodiment of the present invention.

[0052] Figure 10 This is a schematic diagram of the angle template tooling according to an embodiment of the present invention.

[0053] Figure 11 This is a schematic diagram of the web plate hoisting according to an embodiment of the present invention.

[0054] Figure 12 This is a schematic diagram of a special hoisting tool according to an embodiment of the present invention.

[0055] Figure 13 This is a schematic diagram of the connection structure between the fixed ruler and the L-shaped plate in an embodiment of the present invention.

[0056] The attached diagram is labeled as follows: 11. Basic frame; 12. Horizontal crossbar; 13. Vertical support one; 14. Vertical support two; 15. Vertical support three; 16. Vertical support four; 17. Diagonal brace; 18. Adjusting nut; 19. Locking nut; 20. Adjusting bolt; 21. Fixed scale; 22. Scale connecting plate; 23. Detachable scale; 24. Scale mounting positioning pin; 25. Scale mounting reference base; 26. Top plate; 27. Rib plate; 28. Counterweight block. Detailed Implementation

[0057] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. Of course, the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0058] Example 1

[0059] See Figures 1 to 12 According to Table 1, the present invention provides a technical solution as follows: a curved panel unit, including a web arc-shaped frame, the web arc-shaped frame including a base frame 11 and a vertical support group and a diagonal brace 17 disposed on the base frame 11.

[0060] The vertical support group includes vertical support one 13, vertical support two 14, vertical support three 15, and vertical support four 16;

[0061] The two ends of the diagonal brace 17 are respectively connected to a fixed ruler 21 and a detachable ruler 23, and a ruler connecting plate 22 is provided in the middle of one end of the diagonal brace 17.

[0062] The horizontal angle of the diagonal brace 17 is basically consistent with the inclination angle of the web plate.

[0063] Several evenly distributed adjusting nuts 18, locking nuts 19, and adjusting bolts 20 are provided on the diagonal cross brace 17; the first adjusting nut 18 and locking nut 19 are 150mm away from the end of the diagonal cross brace 17, and the remaining adjusting nuts 18 and locking nuts 19 are arranged vertically on the upper part of the diagonal cross brace 17 at intervals of 1000mm.

[0064] Adjusting bolts 20 are vertically installed on the upper part of the diagonal cross brace 17 at intervals of 1m via adjusting nuts 18 and locking nuts 19.

[0065] The fixed ruler 21 is perpendicular to the diagonal brace 17; the detachable ruler 23 is perpendicular to the diagonal brace 17 and is connected to the diagonal brace 17 through the ruler mounting positioning pin 24; the bottom of the detachable ruler 23 is provided with a ruler mounting reference seat 25.

[0066] The basic frame 1 is equipped with a stiffening plate 27 inside, and a counterweight block 28 is installed on the top of the stiffening plate 27. One side of the stiffening plate 27 is connected to the top plate 26.

[0067] A method for fabricating a curved panel unit includes the following steps:

[0068] Step 1, Design of Curve Control Transformation:

[0069] Based on the web's linear data, a 3D model is created using software. A unified reference coordinate system for the web is established with the beam segment center for ease of control and fabrication. 3D coordinate data of the intersection points of the corresponding transverse reference line and the 2m data line are provided every 2m interval. The intermediate points are optimized to be straight lines for easier control. Within a plate thickness range of 8–50mm, an arc shape can be achieved through self-weight and additional counterweights, supplemented by fire correction. Figure 1 , Figure 2 As shown in Table 1;

[0070] Table 1 shows the representation of the marker point size data in the embodiments of the present invention:

[0071] Marker point data table (left side)

[0072] Mark L11 (mm) L12 (mm) H11 (mm) H12 (mm) 1-1 XXX XXX XXX XXX 2-2 XXX XXX XXX XXX 3-3 XXX XXX XXX XXX 4-4 XXX XXX XXX XXX 5-5 XXX XXX XXX XXX 6-6 XXX XXX XXX XXX

[0073] Step 2, Fabrication of the web-shaped arc frame:

[0074] The structural foundation frame 11 is horizontally set on the ground; vertical supports 13, 14, 15, and 16 are arranged vertically from left to right on the foundation frame 11 and are aligned with the internal stiffening plates 27 of the foundation frame 1. When the height of vertical supports 13, 14, 15, and 16 is greater than 500mm, a horizontal crossbar 12 is set in the middle of the vertical support group.

[0075] The diagonal brace 17 is connected to vertical support 13, vertical support 2 14, vertical support 3 15, and vertical support 4 16.

[0076] Fixed scale 21 is located at the end of the diagonal brace 17; scale connecting plate 22 is located in the middle of the diagonal brace 17; detachable scale 23 is located at the end of the diagonal brace 17; such as Figure 3 , Figure 4 , Figure 5 , Figure 6 As shown;

[0077] The above-mentioned web-shaped arc-shaped frame is symmetrically manufactured, such as... Figure 3 As shown, this improves the efficiency of web plate manufacturing;

[0078] Step 3: Adjust the support height of the web-shaped arc-shaped frame:

[0079] Adjust the web arc-shaped frame data according to the marked point data, use a total station to fine-tune the height of the adjusting bolt 20, and adjust the inspection line on the locking nut 19 and the adjusting bolt 20 to the same straight line to form an arc-shaped frame;

[0080] Step 4, Web plate hoisting:

[0081] The web plate is placed on the web plate arc-shaped jig with the height adjusted. Through the self-weight of the steel and the curvature formed by the web plate arc-shaped jig, when the steel cannot fit tightly with the support point of the arc-shaped jig, counterweights or heat correction are used to make the material fit tightly with the jig lifting point. After the web plate is formed, reinforcement is added and installed to ensure the arc shape.

[0082] Step 5, Install longitudinal and transverse stiffeners 27:

[0083] Install stiffening plates 27 sequentially, using counterweights 28 for weight during installation to prevent the web plate from arching after welding heat. After the components are installed, check the fit between the web plate components and the jacking points. If the requirements are not met, perform a fire test adjustment. Figure 7 As shown;

[0084] Step 6, Install top plate 26:

[0085] When installing the top plate 26, check the fitting gap between the top plate 26 and the stiffening plate 27. The gap should be ≤1mm. Use the angle template of the top plate 26 and the fitting condition of the stiffening plate 27 to check the angle between the web plate and the top plate 26.

[0086] When creating an angle template, the angle information needs to be transferred from the template surface to the tooling surface; for example... Figure 8 , Figure 9 As shown;

[0087] Step 7, Web plate hoisting:

[0088] Using specialized hoisting equipment, move the web plate unit away from the web plate arc-shaped jig, turn it 90°, and put it into the installation position. Figure 10 , Figure 11 As shown.

[0089] The basic frame 11 is horizontally set on the ground;

[0090] Vertical supports 13, 14, 15, and 16 are sequentially and vertically installed on the foundation frame 11, and are aligned with the internal reinforcing plates 27 of the foundation frame 11.

[0091] The diagonal brace 17 is connected to the top of the vertical support group;

[0092] The two ends of the diagonal brace 17 extend beyond the connection points of vertical support 13 and vertical support 4 16, respectively. A detachable ruler 23 is installed between vertical support 13 and the end of the diagonal brace 17, and a fixed ruler 21 is installed between vertical support 4 16 and the end of the diagonal brace 17. The end of the diagonal brace 17 extends approximately 100mm beyond vertical support 13 and vertical support 4 16.

[0093] When adjusting the height using adjusting nut 18, locking nut 19, and adjusting bolt 20, an auxiliary elevation line is drawn using the scale lines on both sides. When the adjusting bolt coincides with the auxiliary elevation line, the locking nut 19 can be used to lock and position it, making it convenient to adjust the linear elevation.

[0094] When the fixed scale 21 and the detachable scale 23 are connected to the diagonal brace 17, the "zero" mark is aligned with the diagonal brace 17 for easy and accurate reading.

[0095] The detachable ruler 23 and the diagonal brace 17 are positioned and connected by the ruler connecting plate 22 and the ruler mounting positioning pin 24, which facilitates the installation and removal of the detachable ruler 23. If bolts are used for installation, gaps will be generated.

[0096] The contact surfaces between the scale mounting base 25 and the detachable scale 23 need to be milled to ensure that the flatness meets the requirement of 1mm / m, so as to facilitate the reinstallation of the detachable scale 23 after removal.

[0097] The end of the locking nut 19 bolt needs to be ground to avoid damaging the base material.

[0098] Example 2

[0099] See Figure 13 Based on Example 1, L-shaped plates are connected to both ends of the diagonal brace 17. The fixed ruler 21 and the detachable ruler 23 are perpendicular to one side plate of the L-shaped plate and parallel to the edge of the other side plate of the L-shaped plate. Ensuring that both the fixed ruler 21 and the detachable ruler 23 are perpendicular to the diagonal brace 17 ensures the accuracy of the measurement data.

[0100] Example 3

[0101] Based on Example 1, vertical support 13, vertical support 2 14, vertical support 3 15, and vertical support 4 16 are all set as telescopic rods to facilitate adjustment of the angle of the diagonal brace 17.

[0102] Example 4

[0103] Based on Example 1, the adjusting bolt 20 is equipped with scale lines. When the height of the support point is adjusted arbitrarily according to the curvature of the web plate using the adjusting bolt 20 and the locking nut 19, the adjustment data can be accurately obtained, making it more convenient and precise to control and ensuring construction quality.

[0104] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A curved panel unit, characterized in that, It includes a web-shaped arc-shaped frame, which includes a base frame (11) and vertical support groups and diagonal braces (17) provided on the base frame (11). The vertical support group includes vertical support one (13), vertical support two (14), vertical support three (15), and vertical support four (16). The two ends of the diagonal brace (17) are respectively connected to a fixed scale (21) and a detachable scale (23), and a scale connecting plate (22) is provided in the middle of one end of the diagonal brace (17). The horizontal angle of the diagonal brace (17) is basically consistent with the inclination angle of the web plate; The diagonal brace (17) is provided with several evenly distributed adjusting nuts (18), locking nuts (19) and adjusting bolts (20); the first adjusting nut (18) and locking nut (19) are 150mm away from the end of the diagonal brace (17), and the remaining adjusting nuts (18) and locking nuts (19) are arranged vertically on the upper part of the diagonal brace (17) at intervals of 1000mm; Adjusting bolts (20) are vertically installed on the upper part of the diagonal cross brace (17) every 1m / stop via adjusting nuts (18) and locking nuts (19); The fixed scale (21) is perpendicular to the diagonal brace (17); the detachable scale (23) is perpendicular to the diagonal brace (17) and connected to the diagonal brace (17) through the scale mounting positioning pin (24); the bottom of the detachable scale (23) is provided with a scale mounting reference seat (25); The basic frame (11) is provided with a stiffening plate (27) inside, and a counterweight block (28) is provided on the top of the stiffening plate (27). The top plate (26) is connected to one side of the stiffening plate (27). The basic frame (11) is horizontally set on the ground; The vertical supports one (13), two (14), three (15), and four (16) are arranged vertically on the foundation frame (11) in sequence and are aligned with the internal stiffening plates (27) of the foundation frame (11); The diagonal brace (17) is connected to the top of the vertical support group; The two ends of the diagonal brace (17) extend beyond the connection of the vertical support one (13) and the vertical support four (16), respectively. The detachable scale (23) is set at the position between the vertical support one (13) and the end of the diagonal brace (17), and the fixed scale (21) is set at the position between the vertical support four (16) and the end of the diagonal brace (17). The fabrication method based on the curved panel unit includes the following steps: Step 1, Design of Curve Control Transformation: Based on the linear data of the web, a 3D model is created using software, and a unified reference coordinate system for the web is established with the center of the beam segment for easy control and manufacturing. 3D coordinate data of the intersection of the corresponding transverse reference line and the 2m data line are provided every 2m interval. The middle section is optimized into a straight line for easy control. Within the range of 8~50mm in plate thickness, the arc shape can be achieved by using self-weight and additional pressure, supplemented by fire correction. Step 2, Fabrication of the web-shaped arc frame: The structural foundation frame (11) is horizontally set on the ground; vertical supports one (13), vertical supports two (14), vertical supports three (15), and vertical supports four (16) are arranged vertically on the foundation frame (11) from left to right, and are aligned with the internal stiffening plates (27) of the foundation frame (11). When the height of vertical supports one (13), vertical supports two (14), vertical supports three (15), and vertical supports four (16) is greater than 500mm, a horizontal crossbar (12) is set in the middle of the vertical support group. The diagonal brace (17) is connected to vertical support one (13), vertical support two (14), vertical support three (15), and vertical support four (16); A fixed ruler (21) is set at the end of the diagonal brace (17); a ruler connecting plate (22) is set at the middle of the diagonal brace (17); and a detachable ruler (23) is arranged at the end of the diagonal brace (17). The aforementioned web-shaped arc-shaped jig is manufactured symmetrically; Step 3: Adjust the support height of the web-shaped arc-shaped frame: Adjust the web arc frame data according to the marked point data, use a total station to fine-tune the height of the adjusting bolt (20), and adjust the inspection line on the locking nut (19) and the adjusting bolt (20) to the same straight line to form an arc frame; Step 4, Web plate hoisting: The web plate is placed on the web plate arc-shaped jig with the height adjusted. Through the self-weight of the steel and the curvature formed by the web plate arc-shaped jig, when the steel cannot fit tightly with the support point of the arc-shaped jig, counterweights or heat correction are used to make the material fit tightly with the jig lifting point. After the web plate is formed, reinforcement is added and installed to ensure the arc shape. Step 5, Installation of longitudinal and transverse stiffening plates (27): Install the stiffening plates (27) in sequence. When installing the stiffening plates (27), use the weight block (28) to weigh them down to prevent the web plate from arching after welding heat. After the components are installed, check the fit between the web plate components and the lifting point. If the requirements are not met, make fire correction adjustments. Step 6, Top plate (26) installation: When installing the top plate (26), check the fit gap between the top plate (26) and the stiffening plate (27), the gap is ≤1mm; and use the angle template of the top plate (26) and the fit of the stiffening plate (27) to check the angle between the web plate and the top plate (26); When making an angle template, the angle information needs to be transferred from the template surface to the tooling surface. Step 7, Web plate hoisting: Use special hoisting tools to move the web plate unit away from the web plate arc-shaped jig, and turn it 90° to enter the installation state; When adjusting the height of the adjusting nut (18), locking nut (19), and adjusting bolt (20), an auxiliary elevation line is drawn by the scale lines on both sides. When the adjusting bolt coincides with the auxiliary elevation line, the locking nut (19) can be used to lock and position it. When the fixed scale (21), the detachable scale (23) are connected to the diagonal brace (17), the "zero" scale line is aligned with the diagonal brace (17); The detachable scale (23) and the diagonal brace (17) are positioned and connected by the scale connecting plate (22) and the scale mounting positioning pin (24); The contact surface between the scale mounting base (25) and the detachable scale (23) needs to be milled to ensure that the flatness meets the requirement of 1mm / m. The end of the locking nut (19) bolt needs to be ground.

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