A method for assembling a variable diameter pressure steel pipe

Abstract

The present invention provides a variable diameter pressure steel pipe assembly method, comprising an assembly platform and a plurality of assembly adjustment seats; the assembly diameter of the assembly adjustment seats is adjustable, and different processing methods are adopted to assemble the assembly according to the number of segments of the pressure steel pipe, and the assembly is fixed by spot welding; with the cooperation of the assembly platform and the assembly adjustment seat, the purpose of adjusting the assembly diameter, greatly reducing the difficulty of manual operation, improving the degree of mechanization, and improving the assembly efficiency and accuracy is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of hydraulic metal structure manufacturing, in particular to a variable diameter pressure steel pipe assembly method. Background Art

[0002] The water diversion system of water diversion hydropower stations and pumped storage power stations is equipped with a large number of penstocks. The manufacturing quality and efficiency of penstocks are related to the safe operation and engineering cost of the power station. The existing technology for manufacturing large penstocks generally adopts roll forming, and the process flow is as follows.

[0003] Manufacturing process of large pressure steel pipe: ① Expand the cylinder to form a plane shape according to the design drawings, arrange the seams reasonably according to the size of the expansion, the parameters of the plate rolling machine, the specifications of the steel plate, etc., and order the steel plate; ② Cut the blanks and prepare the welding grooves; ③ Roll the plate rolling machine into tiles or full circle arcs with specified curvatures; ④ Draw the inner and outer diameter section lines, cross center lines, seam lines, etc. of the pressure steel pipe on the platform, and arrange and weld a circle of positioning plates at equal intervals along the inner diameter arc line; offset a suitable wedge plate thickness on the outside of the outer diameter arc line, and arrange and weld a circle of adjustment plates at equal intervals; ⑤ Hang the qualified tiles on the corresponding positions on the assembly platform, and the tiles are The joints and the parting lines are aligned, and the inner circle of the tiles is close to the positioning plate; a wedge plate is inserted between the adjustment plate and the tiles on the outside to adjust the arc, and a jack is set on the inside to adjust the inner circle; a guide chain is arranged on the upper end of the tile and the platform is pulled obliquely, or pulled in the diameter direction to adjust the upper roundness and the butt joint gap; after the roundness of the upper and lower end faces and the gap of the tile joints are adjusted to meet the requirements, the butt joint is fixed by positioning welding, which is the vertical assembly method of the pressure steel pipe; ⑥ After the tiles form a section of steel pipe, the welding process is started to weld the butt joints between the tiles, that is, the longitudinal seam of the pressure steel pipe; ⑦ After the longitudinal seam is welded, the roundness is adjusted again. After passing the test, the inner brackets are installed at both ends to fix them, and the subsequent processes such as stiffening ring welding are carried out.

[0004] With the development of wind power and photovoltaic green energy, pumped storage power stations have developed explosively. Pumped storage power stations have high head energy storage, one pipe and two machines configuration, long water pipelines, small water pressure in the upper section, large steel pipe diameter and thin pipe wall, and large water pressure in the lower section, small steel pipe diameter and thick pipe wall, and high-strength steel plates are widely used. Take the parameters of a pumped storage power station under construction as an example: three main pipes with a head of 682m, one pipe and two machines configuration, and 6 350MW vertical shaft single-stage mixed flow reversible pump turbines. The inclined shaft section has a double-step Z-shaped layout with a total length of 1650m. The material is low-alloy container steel and high-strength steel, with a yield strength of 355-800Mpa, a diameter of 6000-2100mm, and a wall thickness of 32-68mm. The pressure steel pipe of the pumped storage power station has the characteristics of high-strength material and pipe diameter and wall thickness that vary with elevation.

[0005] The existing vertical assembly method is to draw the inner and outer arc lines, cross center line, tile seam line, etc. of the pressure steel pipe on the assembly platform, and evenly arrange and weld a circle of positioning plates on the inner diameter arc line, and offset a suitable distance on the outer side of the outer diameter arc line, and evenly arrange and weld a circle of adjustment plates. It is used as a circle assembly platform.

[0006] Rounding the lower end surface: Hang the rolled tiles at the corresponding position, insert a wedge plate (or install a jack) between the adjustment plate and the tile on the outside to reduce the diameter of the tile and make it close to the inner circle positioning plate; adjust the jack on the inside to press the inner wall of the tile to align with the inner arc line, and tighten it in the vertical direction to eliminate the gap between the tiles, so that the tiles on the lower end surface form a full circle to meet the specified standards;

[0007] Upper end face rounding: The upper end face of the tile is adjusted to meet the specification requirements by pulling the guide chain and the platform obliquely or pulling in the diameter direction to adjust the upper end face roundness and the gap between the joints;

[0008] After the roundness of the upper and lower end faces and the gap at the tile joints are adjusted to meet requirements, the tile joints are fixed by positioning welding with an electric welder. The vertical assembly process of the pressure steel pipe is completed and the welding process can be started.

[0009] From the above analysis, it can be seen that the existing vertical assembly method mainly relies on drawing alignment lines on the platform, positioning plate limit alignment, and adjusting the roundness and gap with wedge plates, jacks, and guide chains. It is basically a manual operation with high labor intensity, large alignment errors, long assembly process, and low production efficiency. It is not suitable for large-scale pressure steel pipe assembly. Moreover, the same work station can only be used for the assembly of steel pipes with the same diameter, and there is no variable diameter adjustment function. It is difficult to meet the manufacturing process of large-scale, variable diameter, multi-wall thickness, and high-strength steel pressure steel pipes for pumped storage power stations. Summary of the invention

[0010] The purpose of the present invention is to address the deficiencies in the prior art and thereby provide a variable diameter pressure steel pipe assembly method with adjustable assembly diameter, which greatly reduces the difficulty of manual work, improves the degree of mechanization, and improves assembly efficiency and accuracy.

[0011] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a variable diameter pressure steel pipe rounding method, including a rounding platform and a plurality of rounding adjustment seats;

[0012] The circular platform assembly includes a platform and a plurality of bases distributed in a circular array on the platform, each base is radially distributed around the center of the platform, and four bases on the platform coincide with the cross center line of the platform;

[0013] The base coinciding with the cross center line is installed with the circle adjustment seat, and the other bases may be optionally installed with the circle adjustment seat;

[0014] The circular adjustment seat comprises a base seat, a positioning seat and an adjusting oil cylinder. The base seat is fixedly mounted on the base. The positioning seat can be mounted on the base seat in a linear motion. The moving direction of the positioning seat passes through the center of the platform. A steel pipe clamping groove is formed between the adjusting oil cylinder and the positioning seat. The clamping surface of the positioning seat is an arc surface adapted to the steel pipe.

[0015] The circle is formed by the following method:

[0016] A is for full circle arc combination:

[0017] The four circular adjustment seats that coincide with the cross center line of the platform are activated, and the other circular adjustment seats are abandoned;

[0018] A1. If the inner diameter of the full arc is equal to or slightly larger than the design diameter, adjust the arc surface on the positioning seat of the four circular adjustment seats to be equal to the design inner diameter of the pressure steel pipe, and hoist the steel pipe of the full arc into the steel pipe clamping grooves of the four circular adjustment seats, with the joint coinciding with one of the steel pipe clamping grooves;

[0019] First operate the adjusting cylinder on the side opposite to the joint, push the side wall of the steel pipe on that side tightly and fit it to the arc surface of the positioning plate and lock it, then operate the other two adjusting cylinders at the non-joint side respectively, push the side wall of the steel pipe on the corresponding side tightly and fit it to the arc surface of the positioning plate and lock it, finally check the gap of the whole circle arc on the joint side, if the gap fits together, proceed with the subsequent operation; if the lower end joint is already fitted and the upper end joint gap is too large, set a guide chain above the two adjacent side assembly adjustment seats of the joint and on the upper end surface of the steel pipe to be assembled to tighten the steel pipe, so that the upper and lower gaps of the entire joint are evenly fitted to meet the requirements, then adjust the adjusting cylinder on the joint side to push and lock the joint of the steel pipe to eliminate the misalignment of the joint;

[0020] Check the roundness of the upper and lower heads of the steel pipe and the gap of the joint. After confirming that they are correct, fix the joint gap by positioning welding, release the lock of each group circle adjustment seat, and enter the next welding process;

[0021] A2. If the inner diameter of the full circle is slightly smaller than the design diameter, adjust the arc surface of the positioning seat of the three circle adjustment seats on the joint side and the adjacent side to be 3mm-4mm smaller than the design radius of the pressure steel pipe, adjust the arc surface of the circle adjustment seat on the opposite side of the joint to be equal to the design radius of the pressure steel pipe, and hoist the steel pipe of the full circle into the steel pipe clamping groove of the circle adjustment seat;

[0022] First operate the adjustment cylinder on the opposite side of the joint to press the side wall of the steel pipe on that side tightly against the arc surface of the positioning plate and lock it. Then adjust the positioning seats of the remaining three circular adjustment seats to move outwards and press the side wall of the steel pipe tightly against the arc surface.

[0023] Check the gap on the joint side. If the gap is too large, adjust the positioning seat in the adjacent two-side circular adjustment seat to move inward by 1mm-2mm, and then operate the corresponding adjustment cylinder to press the side wall of the steel pipe against the arc surface of the positioning seat and lock it to eliminate the gap; when the joint gap at the upper end of the whole circle is too large, set a guide chain on the upper end of the steel pipe above the adjacent circular adjustment seat to tighten it to make the joint gap uniform; operate the adjustment cylinder on the joint side to press the side wall of the steel pipe against the arc surface of the positioning seat to eliminate the misalignment;

[0024] Check the roundness of the upper and lower heads of the steel pipe and the gap of the joints. After confirming that they are correct, fix the joint gap by positioning welding, release the lock of each group circle adjustment seat, and enter the next welding process;

[0025] B Penstock Semicircular Tile Group

[0026] B1. When the tile radius is equal to or greater than the design radius, adjust the arc surface of the positioning seat on all the circle adjustment seats to be equal to the design radius, and hoist the tile into the steel pipe clamping groove of the circle adjustment seat. Each tile corresponds to three circle adjustment seats, so that the joint coincides with one of the cross center lines;

[0027] First, operate the adjusting cylinders in the two circular adjustment seats located on the center line of the angle between the two adjacent joints to make the side wall of the steel pipe close to the arc surface of the positioning seat; then check the gap of the first joint. If it is not closed, operate the adjusting cylinders of the two adjacent circular adjustment seats to increase the pressure to close the joint, and then lock the corresponding adjusting cylinder; then check the gap of the second joint. If it is not closed, operate the adjusting cylinders of the two adjacent circular adjustment seats to increase the pressure to close the joint, and then lock the corresponding adjusting cylinder; check the upper and lower gaps of each joint. If there is no gap, proceed to the subsequent operation. If the upper gap is too large, add a guide chain to the upper end of the tile to tighten it, and then proceed to the subsequent operation after eliminating the gap;

[0028] Operate the circular adjustment seat at the joint to eliminate the joint misalignment, and then lock the corresponding adjustment cylinder; check the roundness of the upper and lower heads of the pressure steel pipe and the joint gap, and after confirming that they are correct, perform positioning welding to fix the joint, release the lock of each circular adjustment seat, and enter the next welding process;

[0029] B2. When the tile radius is smaller than the design radius, adjust the arc surface of the positioning seat on the circle adjustment seat of the corresponding joint to be equal to the design radius, and adjust the arc surface of the positioning seat on the other circle adjustment seats to be 3mm-4mm smaller than the design radius, and hang the tile in the steel pipe clamping groove of the circle adjustment seat;

[0030] First, operate the adjustment cylinders in the two circular adjustment seats located on the center line of the angle between the two adjacent joints to drive the tile to move 1mm-2mm inward, lock the adjustment cylinder, and then fine-tune the positioning seat to move outward to tighten the side wall of the steel pipe to the arc surface; repeat the above process to make preliminary adjustments to each tile;

[0031] Observe the gap at the joint. If the gap is eliminated, proceed to the subsequent steps. If the gap still exists, repeat the above steps until the distance that the oil cylinder drives the tile to move inward reaches 3mm-4mm. If the gap still exists, continue the following adjustments:

[0032] Check the first gap. If it is not closed, control the adjusting cylinders of the two adjacent group circle adjustment seats to pressurize the steel pipe side wall until the gap is eliminated and locked; check other gaps in turn. If they are not closed, control the adjusting cylinders of the two adjacent group circle adjustment seats to pressurize the steel pipe side wall until the gap is eliminated and locked; check the joints on the top of the tiles. If there is a gap, increase the guide chain tension to eliminate the upper gap and make the joints uniform up and down;

[0033] Finally, control the adjusting cylinder at the joint to eliminate the misalignment of the joint, and then lock the corresponding adjusting cylinder; check the roundness of the upper and lower heads of the pressure steel pipe and the joint gap, and after confirmation, fix the joint by positioning welding, release the lock of each group of circular adjustment seats, and proceed to the next welding process.

[0034] As described above, the base seat is a fixed seat, a screw transmission mechanism is installed on the base seat, the movement direction of the screw transmission mechanism is consistent with the length direction of the base seat, and the upper end surface of the base seat is a support limit surface that slides with the positioning seat;

[0035] The positioning seat is installed at the action end of the screw transmission mechanism, and the bottom end of the positioning seat is slidably matched with the upper end surface of the base seat, so that the positioning seat can perform linear reciprocating motion along the upper end surface of the base seat, and the rear end surface of the positioning seat is an arc surface;

[0036] The regulating oil cylinder is installed on the base seat and is located behind the positioning seat. A steel pipe clamping groove is formed between the piston end of the regulating oil cylinder and the positioning seat.

[0037] As described above, the foundation seat includes two main beams, two end plates, an upper plate and a plurality of lower plates. The main beam is composed of two channel steels which are back to back and keep a certain distance. The upper limbs of the two channel steels are connected to an upper plate, and the lower limbs of the two channel steels are connected to a plurality of lower plates. The two end plates are respectively installed at the front end and the rear end.

[0038] A long slot is provided at the center of the upper plate along the length direction, and the action end of the screw transmission mechanism passes through the long slot and slides in the long slot;

[0039] The end plate is provided with a mounting hole for mounting a screw transmission mechanism.

[0040] Based on the above, the screw transmission mechanism includes a screw, a screw nut, a locking nut and a pair of thrust bearings. The screw is a hexagonal prism, a circular step, a trapezoidal thread segment and a triangular thread segment from the large end to the small end. The two ends of the screw pass through the two end plates and are respectively installed with the thrust bearings. The small end is installed on the front end plate through the locking nut and the positioning pin, and the large end is located on the rear end plate as an adjustment end.

[0041] The screw nut is threadably matched with the trapezoidal thread segment. The screw nut, as the action end of the screw transmission mechanism, passes through a long slot and is provided with a plurality of bolt holes. The positioning seat is fixed to the top end of the screw nut by adjusting a gland and screws.

[0042] Based on the above, the front end of the positioning seat is provided with a right-angled trapezoidal reinforcement rib, and the bottom end of the positioning seat is provided with a positioning hole and a mounting hole corresponding to the screw nut. The positioning hole is used to adapt and position with the top structure of the screw nut, and the mounting hole is used to cooperate with the adjustment cover and the screw to lock the screw nut.

[0043] Based on the above, a scale is provided on the side surface of the upper plate of the base seat, and a scale groove is correspondingly provided on the side surface of the positioning seat.

[0044] Based on the above, the adjusting cylinder is installed on the base seat based on the cylinder seat, and the horizontal installation position of the adjusting cylinder in the cylinder seat is adjustable to adapt to different stroke requirements.

[0045] Based on the above, the regulating cylinder is a double-acting cylinder.

[0046] Based on the above, a plurality of bolt connection holes are provided at the bottom end of the base seat for locking and installing the base seat.

[0047] The present invention has outstanding substantive features and significant progress compared to the prior art. Specifically, the present invention has the following advantages:

[0048] 1. Variable diameter circle forming at the same station

[0049] Minimum diameter penstock assembly: install the adjustment seat on the anchor bolt closest to the center of the circle; use a hexagonal wrench to turn the screw to move the outer arc surface of the arc plate on the positioning seat to the position closest to the center of the assembly circle, so that its distance from the center of the assembly circle is equal to the radius of the penstock; adjust the bolt hole position of the cylinder seat on the base seat so that the distance from the end face of the double-acting cylinder piston rod (in retracted state) to the outer arc surface of the arc plate of the positioning seat is not greater than the movement stroke of the cylinder piston, and tighten the connecting bolts between the cylinder seat and the base seat. Install the hydraulic oil pipe and hydraulic station, and after no-load test, the minimum diameter penstock assembly can be carried out.

[0050] Assembling a circle for pressure steel pipes with larger diameters: When assembling a circle for pressure steel pipes with larger diameters without changing the installation position of the adjustment seat, move the cylinder seat to the last row of mounting holes on the upper plate of the base seat and fix it with the connecting bolts; use an inner hexagonal wrench to rotate the screw to move the locating seat to the outside, and make its distance from the center of the circle equal to the radius of the pressure steel pipe; the distance from the outer arc surface of the arc plate of the locating seat to the end face of the cylinder piston rod (in the retracted state) is not greater than the moving stroke of the cylinder piston, and then the pressure steel pipes with larger diameters within the setting range of the adjustment seat can be assembled.

[0051] 2. Move and adjust the anchor bolt position to form a larger diameter pressure steel pipe

[0052] When assembling a larger diameter pressure steel pipe that exceeds the setting range of the adjustment seat, remove the anchor bolts and nuts of the adjustment seat, move the adjustment seat outward by a suitable distance, reinstall and fix it, and then the larger diameter pressure steel pipe can be assembled.

[0053] 3. It can meet the needs of various segmented tile circles and full circle arc circles.

[0054] 4 adjustment seats are installed symmetrically along the cross center line of the foundation to meet the requirements of the full circle arc. 8 adjustment seats are installed symmetrically along the center line of the foundation to meet the requirements of 2 semicircular tiles and 4 tiles. 6 adjustment seats are installed symmetrically along the center of the circle with an interval of 60° to meet the requirements of 3 tiles.

[0055] 4. Improve the automation level of the operation process and the efficiency of the circle

[0056] The adjustment seat combines the screw rod, nut and hydraulic cylinder into one, and combines manual position adjustment with hydraulic rounding and seam pressing to improve the automation level of the operation process and the rounding efficiency, making dimensional measurement, inspection and quality control easier to achieve and ensure, thereby improving the manufacturing technology level. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 It is an assembly schematic diagram for forming a full circle in the present invention.

[0058] Figure 2 It is a stereogram used for forming a full circle in the present invention.

[0059] Figure 3 It is a distribution diagram of the circle-forming platforms used for forming a full circle in the present invention.

[0060] Figure 4 It is a schematic diagram of the assembly of the segmented tiles into a circle in the present invention.

[0061] Figure 5 It is a stereogram of a segmented tile circle in the present invention.

[0062] Figure 6It is a distribution diagram of the circle-forming platform used for the segmented tile circle-forming in the present invention.

[0063] Figure 7 It is a structural schematic diagram of the circular adjustment seat in the present invention.

[0064] Figure 8 It is a cross-sectional view of the circular adjustment seat in the present invention.

[0065] In the figure: 1. Base seat; 2. Screw transmission mechanism; 3. Positioning seat; 4. Adjusting cylinder; 5. Steel pipe clamping groove; 6. Steel pipe; 7. Round platform; 8. Round adjustment seat; 9. Base; 11. Upper plate; 12. End plate; 13. Channel steel; 14. Bolt connection hole; 15. Long slot; 21. Screw; 22. Screw nut; 23. Locking nut; 24. Thrust bearing; 25. Positioning pin; 26. Adjusting end; 31. Adjusting cover; 32. Screw; 33. Arc surface; 34. Right-angle trapezoidal reinforcement rib. DETAILED DESCRIPTION

[0066] The technical solution of the present invention is further described in detail below through specific implementation methods.

[0067] As 1- Figure 8 As shown, a variable diameter pressure steel pipe rounding method includes a rounding platform 7 and a plurality of rounding adjustment seats 8;

[0068] The circular platform 7 comprises a platform and a plurality of bases 9 distributed in a circular array on the platform, each base is radially distributed around the center of the platform, and at least four bases in each platform coincide with the cross center line of the platform;

[0069] The base coinciding with the cross center line must be installed with the circle adjustment seat 8, and the other bases may be optionally installed with the circle adjustment seat 8;

[0070] The circle-forming adjustment seat 8 includes a base seat 1 , a screw transmission mechanism 2 , a positioning seat 3 and an adjusting cylinder 4 .

[0071] The base seat 1 is a fixed seat, the screw transmission mechanism 2 is installed on the base seat 1, the movement direction of the screw transmission mechanism 2 is consistent with the length direction of the base seat 1, and the upper end surface of the base seat 1 is a supporting limit surface that slides with the positioning seat 3.

[0072] Specifically, the base includes two main beams, two end plates, an upper plate 11 and several lower plates. The main beam is composed of two channel steels 13 back to back and maintaining a certain distance. The upper limbs of the two channel steels 13 are connected to an upper plate 11, and the lower limbs of the two channel steels 13 are connected to several lower plates. Two end plates 12 are installed at the front end and the rear end respectively.

[0073] A long slot 15 is provided at the center of the upper plate 11 along the length direction, and the action end of the screw transmission mechanism passes through the long slot and slides in the long slot;

[0074] The bottom surface of the base 1 is provided with a plurality of bolt connection holes 14 for locking and installing the base.

[0075] The screw transmission mechanism 2 includes a screw 21, a screw nut 22, a locking nut 23 and a pair of thrust bearings 24. The screw 21 is a hexagonal prism, a circular step, a trapezoidal thread segment and a triangular thread segment from the large end to the small end. The two ends of the screw 21 pass through the two end plates 12 and are respectively installed with the thrust bearings 24. The small end is installed on the front end plate through the locking nut 23 and the locating pin 25, and the large end is located on the rear end plate as an adjustment end 26. The adjustment end 26 is adjusted using an internal hexagonal wrench in this embodiment, and the position of the locating seat can be directly adjusted through the screw transmission mechanism.

[0076] The screw nut 22 is threadably matched with the trapezoidal thread segment. The screw nut 22, as the action end of the screw transmission mechanism, passes through the long slot 15 and is provided with a plurality of bolt holes. The action end of the screw transmission mechanism is slidably matched with the long slot.

[0077] The positioning seat 3 is fixed to the top end of the screw nut 22 by adjusting the pressure cover 31 and the screw 32 .

[0078] The bottom end of the positioning seat 3 is slidably matched with the upper end surface of the base seat 1, so that the positioning seat 3 can perform linear reciprocating motion along the upper end surface of the base seat 1. A scale is provided on the side of the upper plate of the base seat, and a scale groove is correspondingly provided on the side of the positioning seat for obtaining the moving distance.

[0079] The rear end face of the positioning seat 3 is an arc surface 33, and the front end of the positioning seat 3 is provided with a right-angled trapezoidal reinforcement rib 34. The bottom surface of the positioning seat 3 is provided with a positioning hole and a mounting hole corresponding to the screw nut 22. The positioning hole is used to adapt and position with the top structure of the screw nut 22, and the mounting hole is used to cooperate with the adjustment cover 31 and the screw 32 to lock with the screw nut 22.

[0080] The adjusting cylinder 4 is a double-acting cylinder, which is installed on the base seat 1 based on the cylinder seat and is located behind the positioning seat 3 . A steel pipe clamping groove 5 is formed between the piston end of the adjusting cylinder 4 and the positioning seat 3 .

[0081] Taking eight circular adjustment seats as an example, the installation foundation of the adjustment seat is set on a flat site, and a circle of eight foundation long grooves are excavated along the M-shaped line in the center of the circle. According to the minimum and maximum radius difference of the pressure steel pipe required to be assembled, the installation hole position of the adjustment seat bottom plate, two rows of anchor bolts are arranged symmetrically with each radius line of the M-shaped line and the hole spacing is equal. Concrete is poured to embed the anchor bolts in the foundation long grooves, and a long steel plate with holes is set on the foundation to allow the anchor bolts to pass through this plate to expose a suitable height, which is used as a basic pad for installing the adjustment seat.

[0082] The foundation bolts are arranged into 8 groups according to the center line of the cross. When assembling the segmented tiles of the pressure steel pipe, 8 adjustment seats are installed; when assembling the full arc of the pressure steel pipe, 4 adjustment seats are installed on the cross center line. It is prepared for use later.

[0083] When assembling the minimum diameter pressure steel pipe, install the adjustment seat on the anchor bolt closest to the center of the circle, adjust the upper plate of the base seat to be horizontal, and the flatness should not exceed 0.5mm. Install the nut gasket of the anchor bolt to fix the adjustment seat; use a hexagonal wrench to turn the screw to adjust the distance from the outer arc surface of the arc plate on the positioning seat to the center of the assembly circle to be equal to the radius of the pressure steel pipe. The outer arc distance of the arc plate on the positioning seat relative to the two adjustment seats is equal to the diameter of the pressure steel pipe, and record the outer arc surface position scale of the arc plate for backup; according to the working stroke of the double-acting oil cylinder, adjust the bolt position of the oil cylinder seat on the base seat, which is the distance from the end face of the double-acting oil cylinder piston rod (retracted state) to the outer arc surface of the positioning seat arc plate, which is not greater than the working stroke of the oil cylinder, and tighten the connecting bolts between the oil cylinder seat and the base seat. Install the hydraulic oil pipe and hydraulic station, and after the no-load test machine is correct, the pressure steel pipe can be assembled.

[0084] When assembling a larger diameter pressure steel pipe without changing the installation position of the adjustment seat, move the cylinder seat to the last row of mounting holes on the upper plate of the base seat and fix it with bolts; use an inner hexagonal wrench to rotate the screw rod to move the locating seat to the outside. The distance from the outer arc surface of the arc plate of the locating seat to the end face of the cylinder piston rod (in retracted state) is not greater than the working stroke of the cylinder, then the larger diameter pressure steel pipe within the setting range of the adjustment seat can be assembled.

[0085] When the pressure steel pipe with a larger diameter is assembled beyond the setting range of the adjustment seat, remove the anchor bolts and nuts of the adjustment seat, move the adjustment to the outside for a suitable distance, reinstall and fix it, and then the pressure steel pipe with a larger diameter can be assembled. The assembly can be performed by the following methods:

[0086] like Figure 1 As shown, it is a circle arc of the penstock.

[0087] The pressure steel pipe with a smaller diameter generally has only one longitudinal joint, and the plate rolling machine rolls it into a full circle arc. After the full circle arc is accepted, the four adjustment seats installed on the cross center line of the foundation are used to assemble the circle. The four adjustment seats are located in the north-south and east-west directions, named: 1# north adjustment seat, 2# south adjustment seat, 3# west adjustment seat, 4# east adjustment seat.

[0088] 1.1 Positive deviation full circle arc combination

[0089] If the inner diameter of the full circle is equal to or slightly larger than the design diameter, adjust the relative distance of the outer arcs of the arc plates on the positioning seats of the four adjustment seats to be equal to the inner diameter of the assembled pressure steel pipe. The full circle is hung on the adjustment seat, located between the arc plate of the positioning seat and the piston rod of the oil cylinder, with the joint located in the west. The specific steps for assembling the circle are as follows:

[0090] ① Operate the control valve of the hydraulic station to extend the piston of the 4# adjusting seat to press the east side wall tightly, fit it on the arc surface of the arc plate of the positioning seat, and lock the piston position;

[0091] ② Operate the control valve of the hydraulic station to extend the piston of the 1# adjusting seat to press the north wall plate tightly against the arc surface of the arc plate of the positioning seat, and lock the piston position;

[0092] ③ Operate the control valve of the hydraulic station to extend the piston of the 2# adjusting seat to press the south wall plate tightly, fit it on the arc surface of the arc plate of the positioning seat, and lock the piston position;

[0093] ④ Check the gap between the full circle arc and the joint on the west side. Because the inner diameter of the full circle arc is equal to or slightly larger than the diameter of the group circle, the longitudinal seam should eliminate the gap and fit together under the action of the adjustment seat cylinder on the east, north and south sides; when the longitudinal seam gap on the top of the full circle arc is too large, set the guide chain in the north-south direction to tighten it to ensure that the longitudinal seam gap is uniform.

[0094] Operate the hydraulic station control valve again to extend the piston of the 3# adjustment seat to tighten the wall plate at the west joint, eliminate the misalignment of the joint, and fit the inner side on the arc surface of the arc plate of the positioning seat to lock the piston position. Check the roundness of the upper and lower heads of the pressure steel pipe and the longitudinal seam gap. After confirming that there is no error, fix the longitudinal seam of the joint by positioning welding. After completion, unload the hydraulic station control valve and return. The pressure steel pipe is transported and welded in the welding process to weld the longitudinal seam, and then another section is assembled into a circle.

[0095] 1.2 Negative deviation full circle arc combination

[0096] If the inner diameter of the full circle is slightly smaller than the design diameter, adjust the outer arc of the arc plate on the positioning seat of the 1#, 2#, and 3# adjustment seats on the north and south sides to a position 4mm smaller than the radius of the assembled pressure steel pipe, and adjust the outer arc of the arc plate on the positioning seat of the 4# adjustment seat to be equal to the radius of the assembled pressure steel pipe. The full circle arc is hung on the adjustment seat, located between the arc plate of the positioning seat and the piston rod of the oil cylinder, and the joint is located in the west. The specific steps for assembling the circle are as follows:

[0097] ① Operate the control valve of the hydraulic station to extend the piston of the 4# adjusting seat to press the east side wall tightly, fit it on the arc surface of the arc plate of the positioning seat, and lock the piston position;

[0098] ②Use a hexagonal wrench to rotate the screw of the 1# adjustment seat to adjust the arc plate of the positioning seat to move outward and tighten the inner dome of the north wall plate;

[0099] ③Use a hexagonal wrench to rotate the screw of the 2# adjustment seat to adjust the arc plate of the positioning seat to move outward and tighten the inner dome of the south wall plate;

[0100] ④ Use an inner hexagon wrench to rotate the screw of the 3# adjustment seat to move the arc plate of the adjustment seat outward and tighten the inner dome of the west wall panel.

[0101] Check the longitudinal gap of the full-circle arc joint on the west side. If the gap is too large, adjust the 1# and 2# adjustment seat positioning plates to move 1-2mm inward, and operate the hydraulic station control valve to extend the cylinder piston to tighten the north and south side wall panels, and the longitudinal gap of the full-circle arc joint can be eliminated. When the longitudinal gap of the full-circle arc upper mouth is too large, set the guide chain in the north-south direction to tighten it to ensure uniform longitudinal gap.

[0102] Operate the hydraulic station control valve again to extend the piston of the 3# adjustment seat to tighten the wall plate at the west joint, eliminate the misalignment of the joint, and fit the inner side on the arc surface of the arc plate of the positioning seat to squeeze the joint flush. Check the roundness and longitudinal seam gap of the upper and lower heads of the pressure steel pipe. After confirming that there is no error, fix the longitudinal seam of the joint by positioning welding. After completion, operate the hydraulic station control valve to unload and return, transfer the pressure steel pipe to the welding process to weld the longitudinal seam, and then make another section of the round.

[0103] like Figure 4 As shown, the semicircular tiles of the penstock are grouped into a circle

[0104] Pressure steel pipes with larger diameters are generally rolled in semicircular arcs, with two longitudinal seams in each section, and rolled into semicircular tiles by a plate rolling machine. After the semicircular tiles are accepted, they are assembled into circles using 8 adjustment seats installed on the center line of the foundation. The 8 adjustment seats are located in the north, south, east, west, northwest, southeast, northeast, and southwest directions, and are named: 1# north side adjustment seat, 2# south side adjustment seat, 3# west side adjustment seat, 4# east side adjustment seat, 5# northwest side adjustment seat, 6# southeast side adjustment seat, 7# northeast side adjustment seat, and 8# southwest side adjustment seat.

[0105] When assembling a circle, two semicircular tiles are placed one south and one north, and the longitudinal seams are located on the 3# west adjustment seat and the 4# east adjustment seat respectively.

[0106] 2.1 Positive deviation semicircular tile assembly

[0107] When the radius of the tile assembly circle is equal to or greater than the radius of the assembly circle, adjust the outer arc of the arc plate on the positioning seat of all adjustment seats to be equal to the inner diameter of the assembled pressure steel pipe. Hang the semicircular tile on the adjustment seat, located between the arc plate of the positioning seat and the piston rod of the oil cylinder, and the joint is located in the east-west direction. The specific operation steps of the assembly circle are as follows:

[0108] ① Operate the control valve of the hydraulic station to extend the piston of the 1# adjusting seat to press the north wall plate tightly against the arc surface of the arc plate of the positioning seat and lock the piston position;

[0109] ② Operate the control valve of the hydraulic station to extend the piston of the 2# adjusting seat to press the south wall plate tightly against the arc surface of the arc plate of the positioning seat to lock the piston position;

[0110] ③ Check the gap of the east longitudinal seam. If it is not closed, operate the hydraulic station control valve to extend the piston of the 7# adjustment seat to tighten the northeast wall plate; operate the hydraulic station control valve to extend the piston of the 6# adjustment seat to tighten the southeast wall plate; the east longitudinal seam can be closed and the piston position is locked;

[0111] ④ Check the gap of the west longitudinal seam. If it is not closed, operate the hydraulic station control valve to extend the piston of the 5# adjustment seat to tighten the northwest wall plate; operate the hydraulic station control valve to extend the piston of the 8# adjustment seat to tighten the southwest wall plate; the west longitudinal seam can be closed and the piston position is locked;

[0112] ⑤ Check the longitudinal seam on the top of the pressure steel pipe. If there is a gap, set a guide chain in the north-south direction to tighten it to eliminate the gap on the top and ensure that the upper and lower gaps of the longitudinal seam are uniform.

[0113] ⑥Operate the hydraulic station control valve again to extend the pistons of the 3# and 4# adjustment seats to tighten the wall panels at the joints, eliminate the misalignment of the joints, make the inner side fit on the arc surface of the arc plate of the positioning seat, and lock the piston position. Check the roundness and longitudinal seam gap of the upper and lower heads of the semicircular tiles. After confirming that they are correct, perform positioning welding to fix the longitudinal seam of the joint. After completion, operate the hydraulic station control valve to unload and return the cylinder piston. Lift the pressure steel pipe away from the assembly position, transfer the welding process to weld the longitudinal seam, and then perform another section of the circle.

[0114] 2.2 Negative deviation semicircular tile assembly

[0115] Adjust the outer arc of the arc plate on the locating seat of the 3# and 4# adjusting seats to be equal to the inner diameter of the assembled pressure steel pipe. Adjust the outer arc of the arc plate on the locating seat of other adjusting seats to a position 4mm smaller than the radius of the assembled pressure steel pipe. Hang the semicircular tile on the adjusting seat, located between the arc plate of the locating seat and the piston rod of the oil cylinder, with the joint located in the east-west direction. The specific steps for assembling the circle are as follows:

[0116] ① Operate the control valve of the hydraulic station to extend the piston of the 1# adjustment seat to push the north wall plate, drive the semicircular tile to move 2mm inward, and lock the piston position; use the hexagonal wrench to rotate the screw rod of the 1# adjustment seat to adjust the arc plate of the positioning seat to move outward, and tighten the inner dome of the north wall plate;

[0117] ② Operate the control valve of the hydraulic station to extend the piston of the 2# adjusting seat to push the south wall plate, and at the same time observe the east-west longitudinal seam, and lock the piston position after closing; use the hexagonal wrench to rotate the screw rod of the 2# adjusting seat to adjust the arc plate of the positioning seat to move outward, and tighten the inner dome of the south wall plate;

[0118] Because the inner diameter of the semicircular tile opening is a negative deviation, the position of the locating seat of the 1# and 2# adjusting seats is 4mm smaller than the radius of the assembled pressure steel pipe. Under the push of the cylinder piston, the arc surface of the arc plate on the locating seat of the 3# and 4# adjusting seats plays a guiding role, which can eliminate the gap between the east-west joints of the two semicircular tiles and close the longitudinal seams. If there is still a large gap in the longitudinal seam, the distance of the piston extension of the 1# and 2# adjusting seats can be increased to 4mm until the longitudinal seam is closed.

[0119] If the longitudinal seam still does not close, it may be caused by the tile ellipse. Make the following adjustments.

[0120] ③ Check the gap of the east longitudinal seam. If it is not closed, operate the hydraulic station control valve to extend the piston of the 7# adjustment seat to a certain distance to tighten the northeast side wall plate; operate the hydraulic station control valve to extend the piston of the 6# adjustment seat to a certain distance to tighten the southeast side wall plate; the gap of the east longitudinal seam can be completely eliminated and the piston position can be locked;

[0121] ④ Check the gap of the west longitudinal seam. If it is not closed, operate the hydraulic station control valve to extend the piston of the 5# adjustment seat to a certain distance to tighten the northwest wall plate; operate the hydraulic station control valve to extend the piston of the 8# adjustment seat to a certain distance to tighten the southwest wall plate; the west longitudinal seam can be closed and the piston position is locked;

[0122] ⑤ Check the longitudinal seams on the top of the semicircular tiles. If there are gaps, set guide chains in the north-south direction to tighten them to eliminate the gaps on the top and ensure that the gaps between the longitudinal seams are uniform.

[0123] ⑥Operate the hydraulic station control valve again to extend the pistons of the 3# and 4# adjustment seats to tighten the wall plates at the joints, eliminate the misalignment of the joints, make the inner side fit on the arc surface of the arc plate of the positioning seat, and lock the piston position. Check the roundness and longitudinal seam gap of the upper and lower heads of the pressure steel pipe after assembly. After confirmation, perform positioning welding to fix the longitudinal seam of the joint. After completion, operate the hydraulic station control valve to unload and return the cylinder piston. Lift the pressure steel pipe away from the assembly position, transfer the welding process to weld the longitudinal seam, and then perform another section of the circle.

[0124] If the super-large pressure steel pipe is divided into three or four tiles, three tiles can be arranged in a circle by 6 groups of adjustment seats, and the adjustment seats are arranged at 60° intervals; four tiles can be arranged in a circle by 8 groups of adjustment seats, and the adjustment seats are arranged at 45° intervals; ensure that each tile is seated on three adjustment seats, the adjustment seats at both ends are used for pressing the seams, and the middle adjustment seat is used for adjusting the circle. When there is a gap in the longitudinal seam above the tile, a guide chain is set to pull it diagonally inward to eliminate it. The operation method is basically the same as that of the semicircular tile and will not be repeated.

[0125] Finally, it should be noted that: The above describes in detail the preferred implementation of this patent, but this patent is not limited to the above implementation. Various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of this patent.

Claims

1. A method for assembling a variable diameter pressure steel pipe, characterized in that: It includes a circle assembly platform and a plurality of circle assembly adjustment seats; The circular platform assembly includes a platform and a plurality of bases distributed in a circular array on the platform, each base is radially distributed around the center of the platform, and four bases on the platform coincide with the cross center line of the platform; The base coinciding with the cross center line is installed with the circle adjustment seat, and the other bases may be optionally installed with the circle adjustment seat; The circular adjustment seat comprises a base seat, a positioning seat and an adjusting oil cylinder. The base seat is fixedly mounted on the base. The positioning seat can be mounted on the base seat in a linear motion. The moving direction of the positioning seat passes through the center of the platform. A steel pipe clamping groove is formed between the adjusting oil cylinder and the positioning seat. The clamping surface of the positioning seat is an arc surface adapted to the steel pipe. The circle is formed by the following method: A is for full circle arc combination: The four circular adjustment seats that coincide with the cross center line of the platform are activated, and the other circular adjustment seats are abandoned; A1. If the inner diameter of the full arc is equal to or slightly larger than the design diameter, adjust the arc surface on the positioning seat of the four circular adjustment seats to be equal to the design inner diameter of the pressure steel pipe, and hoist the steel pipe of the full arc into the steel pipe clamping grooves of the four circular adjustment seats, with the joint coinciding with one of the steel pipe clamping grooves; First operate the adjusting cylinder on the side opposite to the joint, push the side wall of the steel pipe on that side tightly and fit it to the arc surface of the positioning plate and lock it, then operate the other two adjusting cylinders at the non-joint side respectively, push the side wall of the steel pipe on the corresponding side tightly and fit it to the arc surface of the positioning plate and lock it, finally check the gap of the whole circle arc on the joint side, if the gap fits together, proceed with the subsequent operation; if the lower end joint is already fitted and the upper end joint gap is too large, set a guide chain above the two adjacent side assembly adjustment seats of the joint and on the upper end surface of the steel pipe to be assembled to tighten the steel pipe, so that the upper and lower gaps of the entire joint are evenly fitted to meet the requirements, then adjust the adjusting cylinder on the joint side to push and lock the joint of the steel pipe to eliminate the misalignment of the joint; Check the roundness of the upper and lower heads of the steel pipe and the gap of the joint. After confirming that they are correct, fix the joint gap by positioning welding, release the lock of each group circle adjustment seat, and enter the next welding process; A2. If the inner diameter of the full circle is slightly smaller than the design diameter, adjust the arc surface of the positioning seat of the three circle adjustment seats on the joint side and the adjacent side to be 3mm-4mm smaller than the design radius of the pressure steel pipe, adjust the arc surface of the circle adjustment seat on the opposite side of the joint to be equal to the design radius of the pressure steel pipe, and hoist the steel pipe of the full circle into the steel pipe clamping groove of the circle adjustment seat; First operate the adjustment cylinder on the opposite side of the joint to press the side wall of the steel pipe on that side tightly against the arc surface of the positioning plate and lock it. Then adjust the positioning seats of the remaining three circular adjustment seats to move outwards and press the side wall of the steel pipe tightly against the arc surface. Check the gap on the joint side. If the gap is too large, adjust the positioning seat in the adjacent two-side circular adjustment seat to move 1mm-2mm inward, and then operate the corresponding adjustment cylinder to press the side wall of the steel pipe against the arc surface of the positioning seat and lock it to eliminate the gap; when the joint gap on the upper opening of the whole circle is too large, adjust the adjacent circular adjustment seat to A guide chain is set on the upper end of the upper steel pipe to tighten it so that the gap between the joints is uniform; the adjustment cylinder on the joint side is operated to tighten the side wall of the steel pipe against the arc surface of the positioning seat to eliminate misalignment; Check the roundness of the upper and lower heads of the steel pipe and the gap of the joints. After confirming that they are correct, fix the joint gap by positioning welding, release the lock of each group circle adjustment seat, and enter the next welding process; B Penstock Semicircular Tile Group B1. When the tile radius is equal to or greater than the design radius, adjust the arc surface of the positioning seat on all the circle adjustment seats to be equal to the design radius, hoist the tile into the steel pipe clamping groove of the circle adjustment seat, install 8 circle adjustment seats to make the joint coincide with one of the cross center lines; First, operate the adjusting cylinders in the two circular adjustment seats located on the center line of the angle between the two adjacent joints to make the side wall of the steel pipe close to the arc surface of the positioning seat; then check the gap of the first joint. If it is not closed, operate the adjusting cylinders of the two adjacent circular adjustment seats to increase the pressure to close the joint, and then lock the corresponding adjusting cylinder; then check the gap of the second joint. If it is not closed, operate the adjusting cylinders of the two adjacent circular adjustment seats to increase the pressure to close the joint, and then lock the corresponding adjusting cylinder; check the upper and lower gaps of each joint. If there is no gap, proceed to the subsequent operation. If the upper gap is too large, add a guide chain to the upper end of the tile to tighten it, and then proceed to the subsequent operation after eliminating the gap; Operate the circular adjustment seat at the joint to eliminate the joint misalignment, and then lock the corresponding adjustment cylinder; check the roundness of the upper and lower heads of the pressure steel pipe and the joint gap, and after confirming that they are correct, perform positioning welding to fix the joint, release the lock of each circular adjustment seat, and enter the next welding process; B2. When the tile radius is smaller than the design radius, adjust the arc surface of the positioning seat on the circle adjustment seat of the corresponding joint to be equal to the design radius, and adjust the arc surface of the positioning seat on the other circle adjustment seats to be 3mm-4mm smaller than the design radius, and hang the tile in the steel pipe clamping groove of the circle adjustment seat; First, operate the adjustment cylinders in the two circular adjustment seats located on the center line of the angle between the two adjacent joints to drive the tile to move 1mm-2mm inward, lock the adjustment cylinder, and then fine-tune the positioning seat to move outward to tighten the side wall of the steel pipe against the arc surface; Repeat the above process to make preliminary adjustments to each tile; Observe the gap at the joint. If the gap is eliminated, proceed to the subsequent steps. If the gap still exists, repeat the above steps until the distance that the oil cylinder drives the tile to move inward reaches 3mm-4mm. If the gap still exists, continue the following adjustments: Check the first gap. If it is not closed, control the adjusting cylinders of the two adjacent group circle adjustment seats to pressurize the steel pipe side wall until the gap is eliminated and locked; check other gaps in turn. If they are not closed, control the adjusting cylinders of the two adjacent group circle adjustment seats to pressurize the steel pipe side wall until the gap is eliminated and locked; check the joints on the top of the tiles. If there is a gap, increase the guide chain tension to eliminate the upper gap and make the joints uniform up and down; Finally, control the adjusting cylinder at the joint to eliminate the misalignment of the joint, and then lock the corresponding adjusting cylinder; check the roundness of the upper and lower heads of the pressure steel pipe and the joint gap, and after confirmation, fix the joint by positioning welding, release the lock of each group of circular adjustment seats, and proceed to the next welding process.

2. The variable diameter penstock rounding method according to claim 1, characterized in that: The base seat is a fixed seat, a screw transmission mechanism is installed on the base seat, the movement direction of the screw transmission mechanism is consistent with the length direction of the base seat, and the upper end surface of the base seat is a support limit surface that slides with the positioning seat; The positioning seat is installed at the action end of the screw transmission mechanism, and the bottom end of the positioning seat is slidably matched with the upper end surface of the base seat, so that the positioning seat can perform linear reciprocating motion along the upper end surface of the base seat, and the rear end surface of the positioning seat is an arc surface; The regulating oil cylinder is installed on the base seat and is located behind the positioning seat. A steel pipe clamping groove is formed between the piston end of the regulating oil cylinder and the positioning seat.

3. The variable diameter penstock rounding method according to claim 2, characterized in that: The base comprises two main beams, two end plates, an upper plate and a plurality of lower plates. The main beams are composed of two channel steels which are back to back and keep a certain distance. The upper limbs of the two channel steels are connected to an upper plate, and the lower limbs of the two channel steels are connected to a plurality of lower plates. The two end plates are respectively installed at the front end and the rear end. A long slot is provided at the center of the upper plate along the length direction, and the action end of the screw transmission mechanism passes through the long slot and slides in the long slot; The end plate is provided with a mounting hole for mounting a screw transmission mechanism.

4. The variable diameter penstock assembling method according to claim 3, characterized in that: The screw transmission mechanism includes a screw, a screw nut, a locking nut and a pair of thrust bearings. The screw is a hexagonal prism, a circular step, a trapezoidal thread segment and a triangular thread segment from the large end to the small end. The two ends of the screw pass through two end plates and are respectively installed with the thrust bearings. The small end is installed on the front end plate through a locking nut and a positioning pin, and the large end is located on the rear end plate as an adjustment end. The screw nut is threadably matched with the trapezoidal thread segment. The screw nut, as the action end of the screw transmission mechanism, passes through a long slot and is provided with a plurality of bolt holes. The positioning seat is fixed to the top end of the screw nut by adjusting a gland and screws.

5. The variable diameter penstock assembling method according to claim 4, characterized in that: The front end of the positioning seat is provided with a right-angled trapezoidal reinforcement rib, and the bottom end of the positioning seat is provided with a positioning hole and a mounting hole corresponding to the screw nut. The positioning hole is used to adapt and position with the top structure of the screw nut, and the mounting hole is used to cooperate with the adjustment cover and the screw to lock the screw nut.

6. The variable diameter penstock rounding method according to claim 5, characterized in that: A scale is arranged on the side surface of the upper plate of the base seat, and a scale groove is correspondingly arranged on the side surface of the positioning seat.

7. The variable diameter penstock assembling method according to claim 6, characterized in that: The adjusting oil cylinder is installed on the base seat based on the oil cylinder seat, and the horizontal installation position of the adjusting oil cylinder in the oil cylinder seat is adjustable so as to adapt to different stroke requirements.

8. The variable diameter penstock assembling method according to claim 7, characterized in that: The regulating cylinder is a double-acting cylinder.

9. The variable diameter penstock assembling method according to claim 8, characterized in that: The bottom end of the base is provided with a plurality of bolt connection holes for locking and installing the base.

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