Intermediate duplex hoisting method

Abstract

The invention belongs to the technical field of hoisting, and particularly relates to an intermediate duplex hoisting method. The special-shaped temporary lifting lugs are welded to the five equal division points of the top of the front-end middle body and the top of the rear-end middle body respectively in a pairwise mode, the welding strength is ensured through magnetic powder inspection, and the duplex middle body is always in a stable stress state in the hoisting process through standard operation of multiple times of 90-degree overturning; and the deformation risk caused by uneven stress is reduced. Inverted horizontal hoisting and step-by-step overturning reduce the hoisting height and the complexity of transverse displacement, and meanwhile, by means of the synergistic effect of the lifting lugs and the welding platform, it is ensured that workpieces are accurately positioned. The using sequence of the lifting lugs is adjusted in stages, the rear-end middle body and the front-end middle body face upwards alternately, the lifting path is further optimized, and the operation time is shortened.

Description

Technical Field

[0001] The invention belongs to the technical field of hoisting, and in particular relates to an intermediate double hoisting method. Background Art

[0002] The base intermediate double is a composite support-connection structure, which is composed of two sets of independent intermediates through specific methods, such as bolts, welding or mortise and tenon joints, and is installed between the equipment base and the main structure. It has the following functions: Double load-bearing: share the load of the equipment body and improve the overall stability. Dynamic coordination: balance the stress distribution between the double structures and reduce vibration transmission. Installation adaptation: adapt to the docking requirements of complex equipment, such as dual-axis systems and symmetrical units.

[0003] The prior art of the double-jointed lifting process of the intermediate body of the marine diesel engine base faces many challenges due to the lack of a dedicated lifting structure. The traditional lifting method relies on simple lifting cards to fix the double-jointed intermediate body without lifting holes, which results in frequent flipping of the workpiece during the lifting process, which is complicated and time-consuming. In addition, due to the limited contact area between the lifting card and the workpiece, there is a risk of decoupling, which seriously threatens the safety of the operation. Especially when double-jointed lifting of large or heavy intermediate bodies, repeated flipping not only increases equipment loss, but may also cause deformation of the workpiece or reduced welding quality due to uneven force. Although the prior art attempts to alleviate such problems by adding auxiliary support structures, it has failed to fundamentally solve the defects of low lifting efficiency and insufficient safety factor. Therefore, there is an urgent need for a new lifting method that can simplify the operating process, reduce the number of flips and improve the reliability of fixation to meet the needs of efficient and safe production. Summary of the invention

[0004] The present invention is to solve the problems of the prior art of the double-jointed lifting method for the intermediate body of the marine diesel engine base, which requires frequent turning of the workpiece during the lifting process, is complicated and time-consuming to operate, has the risk of decoupling, has low operation safety, and repeatedly turns over, not only increases equipment loss, but also may cause deformation of the workpiece or decrease in welding quality due to uneven force. A double-jointed lifting method for the intermediate body is proposed, which includes the following steps:

[0005] S1: Prepare special-shaped temporary lifting lugs;

[0006] S2: Weld the special-shaped temporary lifting ears to the top of the front intermediate body and the rear intermediate body in pairs, and perform magnetic particle inspection; lift the front intermediate body, the rear intermediate body and their connecting plug plates to the assembly platform and close them to form a double intermediate body with a double structure;

[0007] S3: Invert and hoist the duplex intermediate body to the welding platform, and use the two special-shaped temporary lifting ears on the diagonal line to complete the horizontal movement;

[0008] S4: Conduct the first 90° flip through two special-shaped temporary lifting lugs on the rear-end intermediate body, and place the rear-end intermediate body horizontally upward.

[0009] S5: Use the second simple lifting clamp at the bottom of the rear-end intermediate body to conduct the second 90° flip to place the double intermediate body upright.

[0010] S6: Use the first simple lifting clamp at the bottom of the front-end intermediate body to conduct the third 90° flip to place the front-end intermediate body horizontally upward.

[0011] S7: Use two special-shaped temporary lifting lugs on the front-end intermediate body to conduct the fourth 90° flip to invert the double intermediate body again; complete the entire hoisting process.

[0012] According to an intermediate body double-hoisting method described above, in step S1: The special-shaped temporary lifting lug is a U-shaped symmetric structure and is made of high-strength steel; the arc of its U-shaped groove fits the side walls of the front-end intermediate body and the rear-end intermediate body, and its welding surface is pre-opened with a groove to enhance the welding strength.

[0013] According to an intermediate body double-hoisting method described above, in step S2: Weld the special-shaped temporary lifting lugs to two fifth-points A and B at the top of the front-end intermediate body and two fifth-points C and D at the top of the rear-end intermediate body in pairs respectively. After welding, conduct magnetic particle flaw detection to ensure that there are no crack or porosity defects in the weld.

[0014] According to an intermediate body double-hoisting method described above, in step S3: Lift the front-end intermediate body, the rear-end intermediate body and the connecting plug plate welded with the special-shaped temporary lifting lugs to the assembly platform, and fix them through the connecting plug plate and bolts to form a double intermediate body with a double structure; when closing, it is necessary to ensure that the central axes of the front-end intermediate body and the rear-end intermediate body are parallel, and the parallelism error is controlled within ±1 mm.

[0015] According to an intermediate body double-hoisting method described above, in step S4: Conduct the first 90° flip through the special-shaped temporary lifting lugs on the rear-end intermediate body. When flipping, lift the special-shaped temporary lifting lugs, and the special-shaped temporary lifting lugs are lowered synchronously to avoid the double intermediate body from shaking.

[0016] According to an intermediate body double-hoisting method described above, in step S5: The first simple lifting clamp and the second simple lifting clamp are U-shaped simple lifting clamps, and the inner lining of the U-shaped simple lifting clamp's mouth is a thick rubber pad.

[0017] According to an intermediate body double-hoisting method described above, in step S6: The third 90° flip places the front-end intermediate body horizontally upward. After flipping, detect the flatness of the front-end intermediate body end face through a laser level, and the flatness error ≤ 1 mm / m.

[0018] According to the intermediate double - lifting method described above, in step S7: Before the fourth 90° flip and before landing, pre - lay a thick copper skateboard on the work - piece support of the double - intermediate body to reduce the frictional resistance and ensure the accurate alignment of the work - piece.

[0019] According to the intermediate double - lifting method described above, the welding groove of the special - shaped temporary lifting lug is a single - side V - type, with an angle of 60°, a root face of 2 mm, and a weld penetration depth ≥ 8 mm.

[0020] According to the intermediate double - lifting method described above, in steps S1 to S7: The flipping angle needs to be accurately controlled at 90°, with an error not exceeding ±2°.

[0021] The beneficial effects of the present invention are as follows:

[0022] 1. The special - shaped temporary lifting lugs of the present invention are welded to the five - equal - division points at the tops of the front intermediate body and the rear intermediate body respectively, and the welding strength is ensured by magnetic particle flaw detection, avoiding the potential risk of the traditional lifting clamp being prone to unhooking.

[0023] 2. Through the standardized operation of multiple 90° flips, the double - intermediate body in the present invention is always in a stable stress state during the lifting process, reducing the deformation risk caused by uneven stress. The design of inverted horizontal lifting and step - by - step flipping reduces the complexity of the lifting height and lateral displacement. At the same time, by using the synergistic effect of the lifting lugs and the welding platform, accurate positioning is ensured.

[0024] 3. By adjusting the use order of the special - shaped temporary lifting lugs in stages, with the rear intermediate body and the front intermediate body alternating upwards, the lifting path is further optimized, shortening the operation time. In practical applications, this method can increase the lifting efficiency by more than 30%, and effectively reduce equipment wear and the incidence of safety accidents, and is applicable to the intermediate double - lifting requirements of various types of machine bases. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is the axial structure schematic diagram of the intermediate double - lifting of an intermediate double - lifting method of the present invention.

[0026] Figure 2 is the axial structure schematic diagram of the connection between the rear intermediate body of the intermediate double - body of the present invention and the special - shaped temporary lifting lug.

[0027] Figure 3 is the structure schematic diagram of the connection of the special - shaped temporary lifting lug of the present invention.

[0028] Figure 4 is the left - view of the structure schematic diagram of the intermediate double - lifting of an intermediate double - lifting method of the present invention.

[0029] Figure 5It is a schematic diagram of the first 90° flipping process of an intermediate double lifting method of the present invention.

[0030] Figure 6 It is a schematic diagram of the second 90° flipping process of an intermediate double lifting method of the present invention.

[0031] Figure 7 It is a schematic diagram of the third 90° flipping process of an intermediate double lifting method of the present invention.

[0032] Figure 8 It is a schematic diagram of the fourth 90° flipping process of an intermediate double lifting method of the present invention.

[0033] In the figure: 11, 12, 13, 14-special-shaped temporary lifting ears, 3-connecting plug plate, 4-double intermediate body, 21-front intermediate body, 22-rear intermediate body, 31-first simple lifting card, 32-second simple lifting card. DETAILED DESCRIPTION

[0034] Preferred Embodiments

[0035] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0036] like Figures 1 to 8 As shown: In this embodiment,

[0037] An intermediate double lifting method, characterized by comprising the following steps:

[0038] S1: prepare special-shaped temporary lifting ears 11, 12, 13, 14;

[0039] S2: Weld the special-shaped temporary lifting ears 11, 12, 13, 14 to the top of the front intermediate body 21 and the rear intermediate body 22 in pairs, and perform magnetic particle inspection; hoist the front intermediate body 21, the rear intermediate body 22 and the connecting plug plate 3 to the assembly platform and close them to form a double intermediate body 4 with a double structure;

[0040] S3: Invert and hoist the double-jointed intermediate body 4 to the welding platform, and use the two special-shaped temporary lifting ears 11 and 13 on the diagonal line to complete the horizontal movement;

[0041] S4: Perform a first 90° flip through the two special-shaped temporary lifting ears 13 and 14 on the rear intermediate body 22, so that the rear intermediate body 22 is placed horizontally facing upward;

[0042] S5: Use the second simple lifting clamp 32 at the bottom of the rear-end intermediate body 22 to perform a second 90° flip to make the double-link intermediate body 4 upright.

[0043] S6: Use the first simple lifting clamp 31 at the bottom of the front-end intermediate body 21 to perform a third 90° flip to place the front-end intermediate body 21 horizontally upward.

[0044] S7: Use the two special-shaped temporary lifting lugs 11 and 12 on the front-end intermediate body 21 to perform a fourth 90° flip to invert the double-link intermediate body 4 again; complete the entire lifting process.

[0045] In step S1: The special-shaped temporary lifting lugs 11, 12, 13, and 14 are U-shaped symmetric structures and are made of high-strength steel; the arc of their U-shaped grooves fits the side walls of the front-end intermediate body 21 and the rear-end intermediate body 22, and the welding surface is pre-opened with a groove to enhance the welding strength.

[0046] In step S2: Weld the special-shaped temporary lifting lugs 11, 12, 13, and 14 to the two five-equal points A and B at the top of the front-end intermediate body 21 and the two five-equal points C and D at the top of the rear-end intermediate body 22 in pairs respectively. After welding, perform magnetic particle flaw detection to ensure that there are no cracks or porosity defects in the welds.

[0047] In step S3: Lift the front-end intermediate body 21, the rear-end intermediate body 22, and the connecting plug plate 3 welded with the special-shaped temporary lifting lugs 11, 12, 13, and 14 to the assembly platform, and fix them through the connecting plug plate 3 and bolts to form the double-link intermediate body 4 with a double-link structure; when closing, it is necessary to ensure that the central axes of the front-end intermediate body 21 and the rear-end intermediate body 22 are parallel, and the parallelism error is controlled within ±1 mm.

[0048] In step S4: Perform the first 90° flip through the special-shaped temporary lifting lugs 13 and 14 on the rear-end intermediate body 22. When flipping, lift the special-shaped temporary lifting lugs 13 and 14, and the special-shaped temporary lifting lugs 11 and 12 are lowered synchronously to avoid the double-link intermediate body 4 from shaking.

[0049] In step S5: The first simple lifting clamp 31 and the second simple lifting clamp 32 are U-shaped simple lifting clamps, and the inner lining of the U-shaped simple lifting clamp's mouth is a thick rubber pad.

[0050] In step S6: The third 90° flip places the front-end intermediate body 21 horizontally upward. After flipping, use a laser level to detect the levelness of the end face of the front-end intermediate body 21, and the levelness error ≤ 1 mm / m.

[0051] In step S7: Before landing after the fourth 90° flip, pre-lay a thick copper skateboard on the station bracket of the double-link intermediate body 4 to reduce the frictional resistance and ensure the accurate alignment of the workpiece.

[0052] The welding grooves of the special-shaped temporary lifting lugs 11, 12, 13, and 14 are single-sided V-shaped, with an angle of 60°, a root face of 2 mm, and a weld penetration depth of ≥8 mm.

[0053] In steps S1 to S7: The flipping angle needs to be precisely controlled at 90°, with an error not exceeding ±2°.

[0054] A method for double-lifting intermediate bodies in this embodiment is specifically implemented in detail in combination with the attached drawings and process parameters as follows:

[0055] Step 1: Preparation and installation of special-shaped temporary lifting lugs

[0056] The material of the special-shaped temporary lifting lugs is Q345B low-alloy high-strength steel, with a thickness of 20 mm, a yield strength of ≥345 MPa, and a tensile strength of ≥470 MPa.

[0057] The shape of the special-shaped temporary lifting lugs is arc-shaped, with a radius of curvature R = 150 mm, matching the curvature of the outer wall of the intermediate body; the dimensions of the main body of the special-shaped temporary lifting lugs are 300 mm × 200 mm, and the diameter of the hole at the top is Φ50 mm. A wear-resistant nylon sleeve is lined inside the hole to reduce the wear of the wire rope.

[0058] The welding groove is designed as single-sided V-shaped, with an angle of 60° and a root face of 2 mm to ensure a weld penetration depth of ≥8 mm.

[0059] Welding process: CO2 gas shielded welding is adopted, with a welding wire model of ER50-6 and a diameter of 1.2 mm; the welding current is 220-250 A, the voltage is 28-30 V, and the welding speed is 0.3 m / min.

[0060] Weld the special-shaped temporary lifting lugs 11, 12, 13, and 14 to the five equal division points at the top of the front intermediate body 21 and the rear intermediate body 22 respectively. The distance between two special-shaped temporary lifting lugs is 3 / 5 of the side length at the top of the intermediate body, with an error of ±5 mm.

[0061] After welding, perform 100% magnetic particle testing MT and accept it according to the JB / T 6061 standard to ensure that there are no cracks, lack of fusion, and porosity defects in the weld.

[0062] Step 2: Assembly of the double intermediate body 4

[0063] Installation of the connecting plug 3

[0064] The material of the connecting plug 3 is Q235B, with a thickness of 16 mm, dimensions of 400 mm × 100 mm, and Φ22 mm bolt holes are opened at both ends, with a hole pitch of 300 mm.

[0065] Use 8.8-grade M20 high-strength bolts with a pre-tightening torque of 450 N·m to fix the front intermediate body 21, the rear intermediate body 22, and its connecting plug 3. Apply molybdenum disulfide lubricant to the bolts to reduce friction.

[0066] After closing, use a laser alignment instrument to detect the deviation of the central axes of the front intermediate body 21 and the rear intermediate body 22, and control it within ±1 mm. When the tolerance is exceeded, correct it by adjusting the tightness of the plug bolts.

[0067] For temporary reinforcement, symmetrically weld 4 temporary reinforcing rib plates at the joint of the double-link intermediate body 4. The size of the plates is 100 mm × 50 mm × 10 mm to prevent structural deformation during hoisting.

[0068] Step 3: Invert and lift horizontally

[0069] Hoisting equipment configuration

[0070] Select a 4-strand non-rotating wire rope with a rated load of 50 tons, diameter Φ28 mm, length 6 m, and equip shackles at both ends to connect with two special-shaped temporary lifting lugs 11, 13.

[0071] After the crane hook is attached, adjust the wire rope with a level to ensure that the center of gravity of the double-link intermediate body 4 is located at the midpoint of the connection line of the connection points of the two special-shaped temporary lifting lugs 11, 13 when it is inverted.

[0072] Translate it to the welding platform.

[0073] The crane moves the double-link intermediate body 4 smoothly at a speed of ≤0.5 m / min. Pause when it is 1 m away from the welding platform. The operator calibrates the position with a laser rangefinder. After the deviation is ≤3 mm, slowly lower it to the position.

[0074] Step 4: First 90° flip

[0075] Switch to the second simple lifting clamp 32 at the bottom of the rear intermediate body 22. The lifting speed of one side of the crane is 0.2 m / min, and the other side descends synchronously. The whole flipping process is commanded by two signal workers to ensure that the angle error is ≤±2°.

[0076] After flipping, use a hydraulic jack with a load-bearing capacity of 30 tons to support the four corners of the double-link intermediate body 4 to prevent overturning.

[0077] Installation of the second simple lifting clamp 32

[0078] The second simple lifting clamp 32 is of U-shaped structure, made of 42CrMo, lined with a 5-mm-thick rubber pad. The width of the clamp mouth matches the intermediate body flange, with a tolerance of ±1 mm.

[0079] When installing the second simple lifting clamp 32, use a torque wrench to tighten the bolts to 300 N·m and check that there is no gap between the claw and the workpiece contact surface.

[0080] Step 5: Second 90° flip: Right side up: The two cranes lift synchronously at a speed of 0.3 m / min. Immediately fix the bottom of the double-link intermediate body 4 with a limit block after flipping.

[0081] Step 6: Third 90° flip: The thrust intermediate body faces upward

[0082] Adjust the first simple lifting clamp 31 to the flange of the front intermediate body 1. After flipping, use a laser level to detect the end face flatness, with an error ≤ 1 mm / m Figure 6 。

[0083] Step 7: Fourth 90° flip, final inversion and lifting completed

[0084] Fourth flip and positioning

[0085] Switch to the two special-shaped temporary lifting lugs 11, 12 on the front intermediate body 21. After flipping, the double intermediate body 4 is inverted again, and the crane moves to the final welding station at a speed of 0.4 m / min

[0086] Before landing, pre-lay a 5-mm-thick copper sliding plate on the bracket of the double intermediate body 4 to reduce the frictional resistance and ensure accurate alignment of the workpiece

[0087] Key control points and emergency plans:

[0088] Quality control

[0089] If the non-destructive testing of the welded special-shaped temporary lifting lugs 11, 12, 13, 14 is unqualified, the weld seam needs to be ground to the base metal, re-welded and non-destructively tested again

[0090] If the double intermediate body 4 deviates during the flipping process, immediately suspend the operation and restore the balance by fine-tuning the crane hook position or adding counterweights

[0091] Safety measures:

[0092] Set a warning line with a radius of 15 m in the lifting area, and non-operators are prohibited from entering

[0093] If the wind speed exceeds level 6 (10.8 m / s) during flipping, the operation needs to be aborted, and the workpiece is temporarily fixed on the platform

[0094] Implementation effects and scope of application:

[0095] Through standardized process parameters and precise control, this method compresses the single lifting time to 35 minutes, with an efficiency improvement of 40% compared to traditional methods, and the workpiece deformation is controlled within 0.5 mm. It is applicable to high-precision lifting scenarios of double intermediate bodies such as marine diesel engine seats and heavy pressure vessels, and can support workpieces with a maximum single weight of 80 tons

[0096] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent substitutions or changes, shall be covered by the protection scope of the present invention.

Claims

1. A method for double-jointed lifting of intermediate bodies, characterized in that: The following steps are involved: S1: prepare special-shaped temporary lifting lugs (11, 12, 13, 14); S2: Welding the special-shaped temporary lifting ears (11, 12, 13, 14) to the top of the front intermediate body (21) and the rear intermediate body (22) in pairs, and performing magnetic particle inspection; hoisting the front intermediate body (21), the rear intermediate body (22) and the connecting plug plate (3) to the assembly platform and closing them to form a double intermediate body (4) with a double structure; S3: Invert and hoist the double-jointed intermediate body (4) to the welding platform, and use two special-shaped temporary lifting ears (11, 13) on the diagonal line to complete the horizontal movement; S4: Perform a first 90° flip through the two special-shaped temporary lifting ears (13, 14) on the rear intermediate body (22), so that the rear intermediate body (22) is placed horizontally with the rear end facing upward; S5: Use the second simple hanging card (32) at the bottom of the rear intermediate body (22) to perform a second 90° flip so that the double intermediate body (4) is placed upright; S6: Use the first simple hanging card (31) at the bottom of the front intermediate body (21) to perform a third 90° flip so that the front intermediate body (21) is placed horizontally with the front intermediate body facing upwards; S7: Use the two special-shaped temporary lifting ears (11, 12) on the front intermediate body (21) to perform a fourth 90° flip, so that the double intermediate body (4) is inverted again; and the entire lifting process is completed.

2. The method for double-jointed lifting of intermediate bodies according to claim 1, characterized in that: In step S1: the special-shaped temporary lifting lugs (11, 12, 13, 14) are of U-shaped symmetrical structure and made of high-strength steel; the curvature of the U-shaped groove fits the side walls of the front intermediate body (21) and the rear intermediate body (22), and the welding surface is pre-grooved to enhance the welding strength.

3. The method for double-jointed lifting of intermediate bodies according to claim 1, characterized in that: In step S2, the special-shaped temporary lifting ears (11, 12, 13, 14) are welded in pairs to two quintile points A and B on the top of the front intermediate body (21) and two quintile points C and D on the top of the rear intermediate body (22), and magnetic particle inspection is performed after welding to ensure that the welds are free of cracks or pore defects.

4. The method for double-jointed lifting of intermediate bodies according to claim 1, characterized in that: In step S3: the front intermediate body (21), the rear intermediate body (22) and the connecting plug plate (3) welded with special-shaped temporary lifting ears (11, 12, 13, 14) are hoisted to the assembly platform, and they are fixed by connecting the plug plate (3) and bolts to form a double intermediate body (4) with a double structure; when closing, it is necessary to ensure that the central axes of the front intermediate body (21) and the rear intermediate body (22) are parallel, and the parallelism error is controlled within ±1mm.

5. The method for double-jointed lifting of intermediate bodies according to claim 1, characterized in that: In step S4: the first 90° flip is performed through the special-shaped temporary lifting ears (13, 14) on the rear intermediate body (22). During the flip, the special-shaped temporary lifting ears (13, 14) are lifted and the special-shaped temporary lifting ears (11, 12) are lowered synchronously to prevent the double intermediate body (4) from shaking.

6. The method for double-jointed lifting of intermediate bodies according to claim 1, characterized in that: In step S5: the first simple elevator (31) and the second simple elevator (32) are U-shaped simple elevators, and the U-shaped simple elevator mouths are lined with thick rubber pads.

7. The method for double-jointed lifting of intermediate bodies according to claim 1, characterized in that: In step S6: the front end intermediate body (21) is flipped for the third time by 90° so as to be placed horizontally with the front end intermediate body (21) facing upwards. After flipping, the horizontality of the end surface of the front end intermediate body (21) is detected by a laser level, and the horizontality error is ≤1mm / m.

8. The method for double-jointed lifting of intermediate bodies according to claim 1, characterized in that: In step S7: after the fourth 90° flip and before landing, a thick copper slide plate is pre-laid on the station bracket of the double intermediate body (4) to reduce friction resistance and ensure accurate alignment of the workpiece.

9. The method for double-jointed lifting of intermediate bodies according to claim 1, characterized in that: The welding groove of the special-shaped temporary lifting lugs (11, 12, 13, 14) is a single-sided V-shape with an angle of 60°, a blunt edge of 2 mm, and a weld penetration of ≥8 mm.

10. The method for double-jointed lifting of intermediate bodies according to claim 1, characterized in that: In step S1 to step S7: the flip angle needs to be precisely controlled to be 90°, with an error not exceeding ±2°.

Images