Automatic leveling device and leveling method for cylinder of pressure vessel

Abstract

This invention discloses an automatic leveling device and method for pressure vessel cylinders. The device includes concentric inner and outer rings, with multiple sets of leveling mechanisms arranged circumferentially between the inner and outer rings. Each leveling mechanism consists of arc-shaped leveling blocks, leveling screws, symmetrically arranged leveling guide rods, and a drive mechanism. The drive mechanism drives the leveling screws axially via a worm gear structure, causing the multiple sets of circumferential blocks to synchronously tighten the workpiece. This invention utilizes circumferential multi-point synchronous expansion and contraction to achieve uniform distribution of the welding tolerance between the end cap and the cylinder along the circumferential direction, precisely controlling the welding misalignment. It solves the problems of traditional manual forced assembly with inclined plates and irons, which easily damages the base material, results in high residual stress, requires a large amount of labor, and has low efficiency. The device provides stable positioning and guidance, and is suitable for automated assembly operations of various cylinder specifications.

Description

Technical Field

[0001] This invention relates to the field of pressure vessel processing technology, specifically to an automatic leveling device and method for pressure vessel cylinders. Background Technology

[0002] This invention relates to the field of pressure vessel manufacturing equipment technology, and is particularly applicable to the assembly and leveling of high-parameter pressure vessel cylinders and heads, and cylinders and cylinders before circumferential welding, such as liquid hydrogen, liquid helium, liquid oxygen, LNG tanks, and cryogenic insulation. It can be adapted to the assembly and processing of various pressure-bearing base materials such as carbon steel, stainless steel, and composite materials.

[0003] According to the national standard GB / T150-2024 "Pressure Vessels", there are strict limits on the misalignment of circumferential welded joints in pressure vessels. Excessive misalignment can easily lead to stress concentration, poor fusion, and weakened weld strength. This can result in leakage of the pressure vessel medium, or even fatigue cracks during service, causing pressure equipment failure. Therefore, precise control of the misalignment during the assembly of the cylinder and head is a key quality control process in pressure vessel production. In actual production, due to errors in the cutting and rolling of the cylinder and head, there are dimensional deviations in their outer circumferences, making it difficult for them to be naturally 360° aligned during circumferential welding.

[0004] Currently, the industry's conventional assembly process generally uses a combination of a support plate and a wedge to manually forcefully support and round the assembly. This traditional method has many drawbacks: First, the hard compression of the wedge and support plate can easily scratch the surface of the cylinder and head base material, causing workpiece damage and surface contamination. Second, relying on external force to force leveling will cause local deformation and residual stress in the circumferential seam area. The stress cannot be released after welding, which aggravates weld deformation and makes it difficult to meet the national standard requirements for edge misalignment control. Third, manual assembly requires at least two operators to work together, which involves a large amount of manual labor, high labor intensity, low assembly efficiency, and prominent safety hazards in high-altitude and large-component assembly operations, which is not conducive to the automated and intelligent production line production of pressure vessels.

[0005] Existing simple assembly fixtures are mostly single-point independent pushing structures, which cannot achieve synchronous multi-point feeding in the circumferential direction. The circumferential difference cannot be evenly distributed along the circumferential direction, resulting in poor mitigation of misalignment and difficulty in accurately distributing the 360° assembly tolerance. This still fails to fundamentally solve industry pain points such as excessive misalignment and workpiece deformation under stress. Based on the above-mentioned shortcomings of existing technologies, this paper proposes an automatic leveling device for the cylinder of a pressure vessel. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to address the shortcomings of the prior art by providing an automatic cylinder leveling device and method with multi-point synchronous tightening, circumferential tolerance equal distribution, and automatic leveling.

[0007] The technical problem to be solved by the present invention is achieved by the following technical solution: an automatic leveling device for the cylinder of a pressure vessel, the device comprising an inner ring and an outer ring arranged concentrically, and a plurality of leveling mechanisms circumferentially installed between the inner ring and the outer ring. Each leveling mechanism includes a leveling block, a leveling screw, a leveling guide rod, a leveling nut, and a drive mechanism. The leveling block is placed inside the inner ring, with one side of the leveling block facing the center of the inner ring forming an arc-shaped concave surface for leveling, and the other side away from the center of the inner ring fixedly connected to one end of the leveling screw. The leveling screw passes through the inner and outer rings, with its axis aligned with the center of the inner ring. Several leveling guide rods are provided, with their ends passing through the inner and outer rings and fixed to the outer wall of the leveling block away from the center of the inner ring. Through holes are provided on the inner and outer rings for the leveling screw to pass through. Two leveling nuts are provided, and the two leveling nuts are embedded in the through holes on the inner and outer rings for threaded connection of the leveling screw. The drive mechanism is configured to drive the leveling screw to move along the axial direction of the leveling screw.

[0008] Preferably, the leveling mechanism is provided in eight groups, which are evenly distributed circumferentially between the inner ring and the outer ring.

[0009] Preferably, each of the leveling mechanisms has two leveling guide rods, which are symmetrically arranged on both sides of the leveling screw. Through holes are provided on the inner and outer rings for the leveling guide rods to pass through and fit with clearance.

[0010] Preferably, the axis of the leveling guide rod is parallel to the axis of the leveling screw.

[0011] Preferably, a plurality of connecting ribs are fixedly provided circumferentially between the outer circumferential surface of the inner ring and the inner circumferential surface of the outer ring to fix the inner ring and the outer ring as a whole.

[0012] Preferably, a mounting plate is horizontally fixed between the inner ring and the outer ring, and the drive mechanism is located on the mounting plate.

[0013] Preferably, the drive mechanism includes a housing, within which a turbine, an upper thrust bearing, a lower thrust bearing, a worm gear, and a rotary power mechanism are disposed; the turbine is sleeved on the outer circumferential surface of the leveling screw, and a drive nut is fixedly disposed through and in the middle of the turbine, the inner circumferential surface of the drive nut having an internal thread that can mate with the thread of the leveling screw; the top surface of the upper thrust bearing abuts against the inner wall of the housing, and the bottom surface is fixedly connected to the top surface of the drive nut; the top surface of the lower thrust bearing is fixedly connected to the top surface of the drive nut, and the bottom surface abuts against the inner wall of the housing; one end of the worm gear is rotatably mounted on the inner wall of the housing via a rotary bearing, and the other end is drive-connected to the power output end of the rotary power mechanism; one end of the worm gear is rotatably mounted on the inner wall of the housing via a rotary bearing, and the other end is drive-connected to the power output end of the rotary power mechanism.

[0014] Preferably, a number of lifting lugs are fixedly provided on the top surface of the outer ring.

[0015] Preferably, it also includes a distance sensor group and a pressure sensor group; The distance sensor group includes a distance sensor fixed on the top of the leveling block, and the detection contact of the distance sensor is flush with the side of the leveling block facing the center of the inner ring and is directly opposite the center of the inner ring. The pressure sensor group includes a pressure sensor embedded in the middle of the leveling block.

[0016] Preferably, the steps are as follows: S1. Parameter preset: Based on the outer diameter of the end cap to be assembled, a PLC controller is used to participate in the control operation. It is electrically connected to the rotary power mechanism, distance sensor and pressure sensor, and the reference spacing x is set. x is the distance from the distance sensor to the center of the inner ring minus the reserved margin corresponding to the outer radius of the end cap. S2. Equipment positioning: Use a crane to lift the equipment to the position of the circumferential weld where the cylinder and the head meet, so that each arc-shaped pressure block is arranged to correspond to the weld bevel. S3. Distance Closed-Loop Leveling: The distance sensor at the top of each arc-shaped pressure block collects the distance between itself and the outer wall of the end cap in real time and feeds it back to the PLC; the arc-shaped pressure block with a measured distance greater than x is fed in one step by a displacement of x; the arc-shaped pressure block with a measured distance less than x first completes the first feed according to the measured distance, and after the arc-shaped pressure block with the larger measured distance is fed into place, the difference between x and the measured distance is used as the second feed amount for compensation feed; when all distance sensor values ​​are equal to x, all arc-shaped pressure blocks stop feeding, and the dimensional leveling is completed; S4. Pressure Verification and Reversal: The pressure sensors installed on the contact surface of the arc-shaped pressure block collect the contact pressure signal in real time and transmit it to the PLC. When the detected pressure of the eight pressure sensors tends to be consistent, the PLC controls the drive mechanism to run in reverse, driving each leveling screw to retract, and the arc-shaped pressure block returns to its initial position, completing the entire assembly process.

[0017] Compared with the prior art, the beneficial technical effects of the present invention are: (1) By feeding the leveling blocks of multiple leveling mechanisms synchronously, 360° even grouping error can be achieved, effectively controlling the amount of weld misalignment and meeting the requirements of GB / T150-2024 specification; (2) The arc-shaped pressure block changes the previous method of using sharp objects such as wedges to straighten the workpiece. After its end face is attached to the cylinder, it can avoid scratches and contamination on the workpiece surface as much as possible, and there is no residual stress caused by forced assembly. (3) The worm gear integrated drive allows a single person to work with the overhead crane in the factory to lift the lugs on the top surface of the outer ring. The operation is simple, reduces manpower, and improves assembly efficiency. (4) The leveling guide rod can limit and guide the axial movement of the leveling screw, ensuring the smooth operation of the screw and adapting to pressure vessel pairs with different diameter specifications. Attached Figure Description

[0018] Figure 1 This is a top view of the structure before the invention is used; Figure 2 This is a top view of the structure when the present invention is in use; Figure 3 This is a schematic diagram of the drive mechanism of the present invention without a rotary power mechanism; Figure 4 This is a schematic diagram of the main structure of the leveling block of the present invention.

[0019] Reference numerals: 1. Inner ring; 2. Outer ring; 3. Leveling block; 4. Leveling screw; 5. Leveling guide rod; 6. Leveling nut; 7. Connecting rib; 8. Mounting plate; 9. Housing; 10. Turbine; 11. Upper thrust bearing; 12. Lower thrust bearing; 13. Worm gear; 14. Lifting lug; 15. Drive nut; 16. Distance sensor; 17. Pressure sensor. Detailed Implementation

[0020] The specific technical solutions of the present invention will be further described below with reference to the accompanying drawings, so as to enable those skilled in the art to further understand the present invention, without constituting a limitation on its rights.

[0021] Example 1, referring to Figure 1-3 An automatic leveling device for a pressure vessel cylinder, the device comprising an inner ring 1 and an outer ring 2 arranged concentrically, and a plurality of leveling mechanisms circumferentially installed between the inner ring 1 and the outer ring 2. Each leveling mechanism includes a leveling block 3, a leveling screw 4, a leveling guide rod 5, a leveling nut 6, and a driving mechanism. The leveling block 3 is placed inside the inner ring 1 and is configured as an arc-shaped plate structure. The curvature of the leveling block 3 can be selected according to the usage requirements. One side of the leveling block 3 facing the center of the inner ring 1 forms an arc-shaped concave surface for leveling, and the other side away from the center of the inner ring 1 is fixedly connected to one end of the leveling screw 4. The leveling screw 4 passes through the inner ring 1 and the outer ring 2, and its axis is aligned with the center of the inner ring 1. The leveling guide rod 5 has several sections, the ends of which pass through the inner ring 1 and the outer ring 2 and are fixed to the outer side wall of the leveling pressure block 3 away from the center of the inner ring 1. The leveling guide rod 5 has a cylindrical rod structure. Through holes are opened on the inner ring 1 and the outer ring 2 for the leveling screw 4 to pass through. Two leveling nuts 6 are provided and are embedded in the through holes on the inner ring 1 and the outer ring 2 for threaded connection of the leveling screw 4. The driving mechanism is configured to drive the leveling screw 4 to move along the axial direction of the leveling screw 4.

[0022] In Example 1, the driving mechanism drives the leveling screw 4 to move along the axial direction of the leveling screw 4, so that the leveling pressure block 3 on the end of the leveling screw 4 abuts against the cylinder or cover of the pressure vessel to adjust the position. When the leveling screw 4 is adjusted to the correct position, the cylinder and cover of the pressure vessel are corrected to be collinear.

[0023] Example 2, an automatic leveling device for a pressure vessel cylinder as described in Example 1, wherein the leveling mechanism is provided in eight groups, and the eight groups of leveling mechanisms are evenly distributed circumferentially between the inner ring 1 and the outer ring 2.

[0024] In Example 2, setting up eight sets of leveling mechanisms can make the leveling more efficient and effective.

[0025] Example 3, an automatic leveling device for a pressure vessel cylinder as described in Example 1, wherein each leveling mechanism has two leveling guide rods 5, which are symmetrically arranged on both sides of the leveling screw 4. Through holes are provided on the inner ring 1 and the outer ring 2 for the leveling guide rods 5 to pass through and fit with clearance. The through holes are circular through holes.

[0026] In Example 3, the leveling guide rod 5 can radially limit the movement of the leveling screw 4, thus preventing unnecessary rotation of the leveling guide rod 5 during movement.

[0027] Example 4, an automatic leveling device for a pressure vessel cylinder as described in Example 1, wherein the axis of the leveling guide rod 5 is parallel to the axis of the leveling screw 4.

[0028] Example 5: An automatic leveling device for a pressure vessel as described in Example 1, wherein a plurality of connecting ribs 7 are fixedly provided circumferentially between the outer circumferential surface of the inner ring 1 and the inner circumferential surface of the outer ring 2 to fix the inner ring 1 and the outer ring 2 into one piece. The connecting ribs 7 may be square plate-shaped structures.

[0029] In Example 5, by adding a connecting rib 7 between the inner ring 1 and the outer ring 2, the inner ring 1 and the outer ring 2 can be fixed as one unit.

[0030] Example 6: An automatic leveling device for a pressure vessel cylinder as described in Example 1, wherein a mounting plate 8 is horizontally fixed between the inner ring 1 and the outer ring 2, the mounting plate 8 is a square plate structure and is horizontally arranged, and the driving mechanism is located on the mounting plate 8.

[0031] Example 7, an automatic leveling device for a pressure vessel cylinder as described in Example 1, wherein the driving mechanism includes a housing 9, which may be a square housing 9. Inside the housing 9 are a turbine 10, an upper thrust bearing 11, a lower thrust bearing 12, a worm gear 13, and a rotary power mechanism. The turbine 10 is sleeved on the outer circumferential surface of the leveling screw 4. A driving nut 15 is fixedly installed through the middle of the turbine 10, and the inner circumferential surface of the driving nut 15 has an internal thread that can engage with the threaded leveling screw 4. The top surface of the upper thrust bearing 11 abuts against the inner wall of the housing 9, and its bottom surface is fixedly connected to the top surface of the driving nut 15. The top surface of the lower thrust bearing 12 is fixedly connected to the top surface of the driving nut 15, and its bottom surface abuts against the inner wall of the housing 9. One end of the worm gear 13 is rotatably mounted on the inner wall of the housing 9 via a rotary bearing, and the other end is connected to the power output end of the rotary power mechanism. The rotary power mechanism may be an electric motor.

[0032] Example 8: An automatic leveling device for a pressure vessel cylinder as described in Example 1, wherein several lifting lugs 14 are fixedly provided on the top surface of the outer ring 2.

[0033] In Example 8, the number of lifting lugs 14 can be selected according to the usage requirements. For example, eight lugs can be arranged at intervals. The lifting lugs 14 are metal structures with a circular lifting hole in the middle.

[0034] Example 9, referring to Figure 4 The automatic leveling device for the cylinder of a pressure vessel described in Example 1 further includes a distance sensor group and a pressure sensor group. The distance sensor group includes a distance sensor 16 fixed on the top of the leveling block 3. The detection contact of the distance sensor 16 is flush with the side of the leveling block facing the center of the inner ring and is directly opposite the center of the inner ring. The pressure sensor group includes a pressure sensor 17 embedded in the middle of the leveling block 3.

[0035] Example 10: A leveling method using the automatic leveling device for pressure vessel cylinders described in Examples 1-9, the steps of which are as follows: S1. Parameter preset: Based on the outer diameter of the end cap to be assembled, a PLC controller is used to participate in the control operation. It is electrically connected to the rotary power mechanism, distance sensor 16 and pressure sensor 17, and the reference spacing x is set. x is the distance from the distance sensor 16 to the center of the inner ring minus the reserved margin corresponding to the outer radius of the end cap. S2. Equipment positioning: Use a crane to lift the equipment to the position of the circumferential weld where the cylinder and the head meet, so that each arc-shaped pressure block is arranged to correspond to the weld bevel. S3. Distance Closed-Loop Leveling: The distance sensor 16 at the top of each arc-shaped pressure block collects the distance between itself and the outer wall of the end cap in real time and feeds it back to the PLC; the arc-shaped pressure block with a measured distance greater than x is fed in one step by a displacement of x; the arc-shaped pressure block with a measured distance less than x first completes the first feed according to the measured distance, and after the arc-shaped pressure block with the larger measured distance is fed into place, the difference between x and the measured distance is used as the second feed amount for compensation feed; when the detected values ​​of all distance sensors 16 are equal to x, all arc-shaped pressure blocks stop feeding, and the dimensional leveling is completed; S4. Pressure Verification and Reversal: The pressure sensors 17 installed on the contact surface of the arc-shaped pressure block collect the contact pressure signal in real time and transmit it to the PLC. When the detection pressure of the eight pressure sensors 17 tends to be consistent, the PLC controls the drive mechanism to run in reverse, driving each leveling screw to retract, and the arc-shaped pressure block returns to the initial position, completing the entire assembly process.

Claims

1. An automatic leveling device for the cylinder of a pressure vessel, characterized in that: The device includes an inner ring and an outer ring arranged concentrically, and several sets of leveling mechanisms are circumferentially installed between the inner ring and the outer ring. Each leveling mechanism includes a leveling block, a leveling screw, a leveling guide rod, a leveling nut, and a drive mechanism. The leveling block is placed inside the inner ring, with one side of the leveling block facing the center of the inner ring forming an arc-shaped concave surface for leveling, and the other side away from the center of the inner ring fixedly connected to one end of the leveling screw. The leveling screw passes through the inner and outer rings, with its axis aligned with the center of the inner ring. Several leveling guide rods are provided, with their ends passing through the inner and outer rings and fixed to the outer wall of the leveling block away from the center of the inner ring. Through holes are provided on the inner and outer rings for the leveling screw to pass through. Two leveling nuts are provided, and the two leveling nuts are embedded in the through holes on the inner and outer rings for threaded connection of the leveling screw. The drive mechanism is configured to drive the leveling screw to move along the axial direction of the leveling screw.

2. The automatic leveling device for a pressure vessel cylinder according to claim 1, characterized in that: The leveling mechanism is provided in eight sets, which are evenly distributed circumferentially between the inner and outer rings.

3. The automatic leveling device for a pressure vessel cylinder according to claim 1, characterized in that: Each of the leveling mechanisms described herein has two leveling guide rods, which are symmetrically arranged on both sides of the leveling screw. Through holes are provided on the inner and outer rings for the leveling guide rods to pass through and fit with clearance.

4. The automatic leveling device for a pressure vessel cylinder according to claim 1, characterized in that: The axis of the leveling guide rod is parallel to the axis of the leveling screw.

5. The automatic leveling device for a pressure vessel cylinder according to claim 1, characterized in that: Several connecting ribs are fixed circumferentially between the outer circumferential surface of the inner ring and the inner circumferential surface of the outer ring to fix the inner ring and the outer ring as one unit.

6. The automatic leveling device for a pressure vessel cylinder according to claim 1, characterized in that: A mounting plate is horizontally fixed between the inner and outer rings, and the drive mechanism is located on the mounting plate.

7. The automatic leveling device for a pressure vessel cylinder according to claim 1, characterized in that: The drive mechanism includes a housing, within which are arranged a turbine, an upper thrust bearing, a lower thrust bearing, a worm gear, and a rotary power mechanism. The turbine is sleeved on the outer circumferential surface of the leveling screw, and a drive nut is fixedly mounted through and in the middle of the turbine. The inner circumferential surface of the drive nut has an internal thread that can mate with the thread of the leveling screw. The top surface of the upper thrust bearing abuts against the inner wall of the housing, and its bottom surface is fixedly connected to the top surface of the drive nut. The top surface of the lower thrust bearing is fixedly connected to the top surface of the drive nut, and its bottom surface abuts against the inner wall of the housing. One end of the worm gear is rotatably mounted on the inner wall of the housing via a rotary bearing, and the other end is connected to the power output end of the rotary power mechanism.

8. The automatic leveling device for a pressure vessel cylinder according to claim 1, characterized in that: Several lifting lugs are fixed on the top surface of the outer ring.

9. The automatic leveling device for a pressure vessel cylinder according to claim 1, characterized in that: It also includes a distance sensor group and a pressure sensor group; The distance sensor group includes a distance sensor fixed on the top of the leveling block, and the detection contact of the distance sensor is flush with the side of the leveling block facing the center of the inner ring and is directly opposite the center of the inner ring. The pressure sensor group includes a pressure sensor embedded in the middle of the leveling block.

10. A leveling method using the automatic leveling device for the cylinder of a pressure vessel according to claims 1-9, characterized in that: The steps are as follows: S1. Parameter preset: Based on the outer diameter of the end cap to be assembled, a PLC controller is used to participate in the control operation. It is electrically connected to the rotary power mechanism, distance sensor and pressure sensor, and the reference spacing x is set. x is the distance from the distance sensor to the center of the inner ring minus the reserved margin corresponding to the outer radius of the end cap. S2. Equipment positioning: Use a crane to lift the equipment to the position of the circumferential weld where the cylinder and the head meet, so that each arc-shaped pressure block is arranged to correspond to the weld bevel. S3. Distance Closed-Loop Leveling: The distance sensor at the top of each arc-shaped pressure block collects the distance between itself and the outer wall of the end cap in real time and feeds it back to the PLC; the arc-shaped pressure block with a measured distance greater than x is fed in one step by a displacement of x; the arc-shaped pressure block with a measured distance less than x first completes the first feed according to the measured distance, and after the arc-shaped pressure block with the larger measured distance is fed into place, the difference between x and the measured distance is used as the second feed amount for compensation feed; when all distance sensor values ​​are equal to x, all arc-shaped pressure blocks stop feeding, and the dimensional leveling is completed; S4. Pressure Verification and Reversal: The pressure sensors installed on the contact surface of the arc-shaped pressure block collect the contact pressure signal in real time and transmit it to the PLC. When the detected pressure of the eight pressure sensors tends to be consistent, the PLC controls the drive mechanism to run in reverse, driving each leveling screw to retract, and the arc-shaped pressure block returns to its initial position, completing the entire assembly process.

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