High-precision maintenance method for coal supporting plate of tamping coke oven coal charging car

Abstract

The invention provides a high-precision maintenance method for a coal supporting plate of a tamping coke oven coal charging car, and relates to the technical field of coke oven equipment maintenance, and the high-precision maintenance method comprises the following steps: S1, pretreatment of new and old plates: removing an oxide layer and pollutants on a contact surface of an upper-layer old plate and a lower-layer new plate; s2, drilling and positioning: temporarily fixing the new plate and the old plate through interval spot welding and then synchronously drilling; step S3; the coal supporting plate is cut into a wear section and a reserved section, and a new plate is welded after the wear section is removed; s4, thermal anchoring is conducted, specifically, the rivet is heated, the pose of the coal supporting plate is adjusted, and then riveting is completed; and S5, quality closed-loop detection: carrying out nondestructive detection and vibration stability verification on welding and riveting parts. According to the process, new and old plates are forcibly aligned through a dynamic drilling technology and spot welding, the datum plane deviation is eliminated, and meanwhile, modular segmented replacement is utilized, an undamaged structure is reserved through selective cutting, further thermodynamic synergistic anchoring is conducted, and rivet heating and mechanical leveling cooperate to improve the connection strength.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coke oven equipment maintenance, in particular to a high-precision maintenance method for a coal plate of a charging car of a stamp-charged coke oven. BACKGROUND

[0002] The stamp-charged coke oven is a core equipment in the metallurgical industry, and the coal plate of the charging car bears the functions of conveying and compacting high-temperature coal.

[0003] Under the long-term effects of a thermal load of 200-400 DEG C, an impact load of 10-15 MPa, and corrosion of coke oven gas, the working surface of the coal plate is prone to serious wear (annual wear amount: 8-12 mm), which leads to problems such as a decrease in charging accuracy (actual measurement deviation: greater than or equal to 5 mm) and sealing failure.

[0004] Current mainstream maintenance processes include disassembling the worn coal plate and replacing it as a whole, which takes a long time and causes more than 40% of intact materials to be wasted, and the worn surface is repaired by using continuous surfacing, but the welding heat input causes deformation, which requires secondary machining, and the new and old plates are riveted at room temperature, the pre-tightening force is insufficient, and the rivet loosening period is only 4-6 months, so the common processes have defects such as a long repair time, a high waste rate, poor pre-stress, and easy deformation. SUMMARY

[0005] The present application aims to solve the problems in the background art, and provides a maintenance method to improve the accuracy of maintenance, prolong the reliability of connection, and improve the efficiency of repair.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solution: a high-precision maintenance method for a coal plate of a charging car of a stamp-charged coke oven, comprising: step S1: new and old plate pretreatment: removing the oxide layer and contaminants on the contact surface of the upper old plate and the lower new plate; step S2: drilling positioning: drilling holes simultaneously after temporarily fixing the new and old plates by interval spot welding; step S3: modular segmented replacement: cutting the coal plate into a worn segment and a retained segment, and welding a new plate after removing the worn segment; step S4: thermal anchoring: riveting after heating the rivet and adjusting the pose of the coal plate; and step S5: quality closed-loop detection: nondestructive testing and vibration stability verification are performed on the welded and riveted parts.

[0007] Further, the step S2 further comprises the following specific steps: step S21: spot welding path planning: determining the welding point spacing according to the plate deformation amount, and avoiding the subsequent drilling area; step S22: dynamic welding fixation: applying short-time high-energy welding by using a pulse spot welding machine, and the single-point welding time is less than or equal to 0.5 seconds; step S23: error compensation drilling: monitoring the drilling deviation in real time during the drilling head feeding process, and compensating the error by adjusting the speed; and step S24: welding point removal and finishing: removing the welding points by using a carbon arc gouging, and polishing to a surface roughness Ra of less than or equal to 6.3 microns.

[0008] Further, the step S3 further comprises the following specific steps: step S31: stress-oriented cutting: determine the low-stress cutting position through finite element analysis, and the cutting path is 1 / 4-1 / 3 of the plate length away from the end; step S32: adaptive bevel processing: match the bevel angle according to the plate thickness, and the thickness of the blunt edge is 10%-15% of the plate thickness; step S33: heat input control welding: adopt segmented back welding process, and the length of each segment is ≤80 mm, and the interlayer is cooled to ≤150℃ for continuous welding; and step S34: welding stress release: immediately hammer the weld after welding and implement local annealing.

[0009] Further, the step S4 further comprises the following specific steps: step S41: rivet thermodynamic treatment: heat the rivet to a red plastic state through medium-frequency induction; step S42: pose cooperative adjustment: lift the coal plate by 20-30 mm through a hydraulic jack, and adjust the leveling in real time through a laser level; step S43: multi-stage impact riveting: sequentially implement the pre-tightening, forming and finishing three stages of impact through a pneumatic rivet gun; and step S44: post-riveting treatment: detect the rivet head height ≥8 mm, and spray and cool the overheated area.

[0010] Further, the step S2 further comprises that the welding spot spacing is positively correlated with the plate thickness, and specifically meets the relationship: welding spot spacing S (mm) = 150+10×plate thickness t (mm), wherein t takes the value range of 15≤t≤25 mm.

[0011] Further, the step S3 further comprises that the segmented back welding in step 33 adopts CO2 gas shielded welding, the protective gas flow is 15±2 L / min, and the wire dry extension length is 12-15 mm.

[0012] Further, the step S4 further comprises that the leveling accuracy of the laser level in step 42 is 0.1 mm / m, the jack lifting speed is ≤2 mm / s, and the pressure is maintained for 5 minutes after lifting in place.

[0013] Further, in the step S5, the weld detection adopts ultrasonic flaw detection, wherein the probe frequency is 5 MHz, and the scanning frequency is ≤150 mm / s, and the riveting vibration test amplitude limit value is 0.15 mm.

[0014] Further, the finite element analysis in the step S31 adopts software to establish a three-dimensional model, the grid size is 5 mm×5 mm, the working condition is simulated to load the actual stress of the coal plate, the stress concentration coefficient of the cutting path is determined to be ≤1.2, and the maximum residual stress of the retained section after cutting is ≤120 MPa.

[0015] Further, the impact energy of the multi-stage impact riveting in the step S43 is respectively: 30J in the pre-tightening stage, 50J in the forming stage, and 20J in the finishing stage, the total impact times are 3 times, the interval time between adjacent impacts is greater than or equal to 10 seconds, and the plastic deformation amount of the rivet is controlled in the range of 1.2 to 1.5 times of the diameter.

[0016] The application provides a high-precision maintenance method for a coal supporting plate of a stamping charging car of a stamping coke oven. The application has the advantages that, by means of the dynamic drilling matching technology, the new and old plates are forced to align by spot welding, the reference surface deviation is eliminated, and the connection strength is improved by heating the rivet and mechanical leveling in cooperation by means of the modular segmented replacement. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is a whole process schematic diagram of the application.

[0018] Figure 2 It is a dynamic drilling positioning process schematic diagram of the application.

[0019] Figure 3 It is a modular segmented replacement process schematic diagram of the application.

[0020] Figure 4 It is a thermal anchoring process schematic diagram of the application.

[0021] Figure 5 It is a quality detection closed loop logic diagram of the application. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the application will be apparently and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work belong to the protection scope of the application.

[0023] The following disclosure provides many different embodiments, or examples, for implementing different structures of the application. For the purpose of simplicity and clarity, the description of the specific examples in the following text is described. Of course, they are only examples, and the purpose is not to limit the application. In addition, the reference numbers and / or reference letters in different examples can be repeated in the application, and such repetition is for the purpose of simplification and clarity, and does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the application provides examples of various specific processes and materials, but those skilled in the art can realize the application of other processes and / or the use of other materials.

[0024] The embodiment of the present application provides a high-precision maintenance method for the coal support plate of a ramming coke oven coal loading car. This high-precision maintenance method for the coal support plate of a ramming coke oven coal loading car can achieve forced alignment of the new and old plates by spot welding through dynamic matching drilling technology, eliminate the reference plane deviation, and simultaneously utilize modular segmented replacement: selective cutting to retain the intact structure, further thermodynamic synergistic anchoring: heating rivets and mechanical leveling to synergistically improve the connection strength. The following is a detailed description of the high-precision maintenance method for the coal support plate of a ramming coke oven coal loading car. It should be noted that the description order of the following embodiments does not limit the preferred order of the embodiments.

[0025] The present application is described in detail below with reference to the accompanying drawings and specific implementation methods.

[0026] Example 1

[0027] See also Figures 1-5 In this embodiment, a high-precision maintenance method for a coal supporting plate of a ramming coke oven coal charging car is provided, including: working process: S1 pretreatment: using an angle grinder to remove the oxide layer on the contact surface of the new and old plates, and cleaning with acetone until there is no oil stain; S2 drilling and positioning: temporarily fixing with interval spot welding and then drilling holes (Φ22±0.2mm) simultaneously; S3 segmented replacement: cutting the coal supporting plate into a worn section and a retained section, and welding a new plate; S4 hot riveting anchoring: heating the rivets to a red-hot state, leveling them and then impact riveting them in stages; S5 quality inspection: ultrasonic flaw detection and vibration test verification.

[0028] The following are specific application cases: Step S1: Pretreatment of new and old boards Oxide layer removal: Use an angle grinder equipped with a diamond grinding wheel (grit size 80) to grind the contact surface of the old and new plates at a 30° inclination angle, removing the oxide layer until the metal substrate is exposed. The surface roughness Ra ≤ 12.5μm. After grinding, use a white light interferometer to detect the surface roughness to ensure that the Ra value meets the standard.

[0029] Cleaning contaminants: Use acetone (purity ≥ 99.5%) to soak a non-woven fabric (weight 80g / m²) and wipe the contact surface. Repeat three times until no oil or dirt remains. Finally, use compressed air (pressure 0.6MPa) to blow the surface to ensure that no particles remain.

[0030] Step S2: Drill positioning Spot welding path planning: Based on the thickness of the old plate (t = 20mm), the spacing between weld points was determined according to the formula S = 150 + 10 × 20 = 350mm. The weld points were distributed in a plum blossom pattern, avoiding the subsequent drilling area (Φ22 ± 0.2mm). A laser scriber was used to mark the weld point positions with an error of ≤ 0.5mm.

[0031] Dynamic welding fixation: Using pulse spot welding machine (Model: Miller Electric DeltaWeld 452), set the current to 8000A, single spot welding time to 0.4 seconds, complete the temporary fixation. After welding, use infrared thermal imager (Model: FLIR T840) to detect the heat affected zone width of the welding point ≤3mm.

[0032] Synchronous drilling: Using numerical control drilling machine (Model: Haas DM-2), drill bit speed 280rpm, feed rate 0.15mm / rev, real-time monitoring of drilling deviation. If the deviation is >0.1mm, automatically adjust the speed to 290rpm for compensation, the final hole diameter tolerance is controlled within ±0.05mm.

[0033] Welding point removal and finishing: Using carbon arc gouging (current 350A, carbon rod diameter 8mm) to remove the welding point, then using a belt sander (grit 120) to polish to Ra≤6.3μm. Use surface profilometer to verify surface roughness.

[0034] Step S3: Modular segmented replacement Stress-guided cutting: Based on ANSYS finite element analysis (model grid size 5mm×5mm), determine the cutting path 1 / 3 of the plate length from the end of the coal support plate (i.e. the cutting line is located 800mm from the end), use plasma cutting machine to complete the cutting, the cut width ≤2mm, the residual stress on both sides of the cut after cutting ≤100MPa.

[0035] Adaptive bevel machining: Bevel angle is set to 35°, the thickness of the blunt edge is 12% of the plate thickness (i.e. 2.4mm), using milling machine (Model: Bridgeport Series I) to process the bevel. The bevel angle tolerance is controlled within ±1°, the thickness error of the blunt edge ≤0.2mm.

[0036] Heat input control welding: Using CO2 gas shielded welding machine, set the current to 220A, voltage to 24V, segmentally back-welding each segment length of 70mm. After interlayer cooling to 120℃, continue welding, using contact temperature sensor to monitor the interlayer temperature in real time.

[0037] Welding stress release: Immediately after welding, use a round hammer (weight 1.5kg) to hammer the weld, the hammering force is uniform (impact energy 5J each time). Then use local annealing (heating temperature 300℃, holding time 30 minutes, natural cooling), the annealing area covers 20mm range on both sides of the weld.

[0038] Step S4: Thermal force anchoring Rivet heating: Using medium-frequency induction heating equipment (frequency 10kHz), heat the rivet (material Q345B) to 650℃, real-time monitor the temperature using infrared temperature meter (Model: Fluke 62 Max+), error ±5℃.

[0039] Position collaborative adjustment: use 4 hydraulic jacks (lifting force 50 tons) to synchronously lift the coal plate by 25 mm, and use laser level to feedback the flatness in real time, adjust the deviation to be less than or equal to 0.1 mm / m, and keep pressure for 5 minutes after lifting in place to ensure the stability of the position of the coal plate.

[0040] Multi-stage impact riveting: pneumatic riveting gun impacts three times: pre-tightening stage (30J), forming stage (50J), and finishing stage (20J), with an interval of 15 seconds each time. The plastic deformation of the rivet is controlled to be 1.3 times the diameter (i.e. the rivet with an original diameter of 20 mm is deformed to 26 mm).

[0041] Post-riveting processing: detect the rivet head height to be greater than or equal to 8 mm, spray cooling water on the overheated area (flow rate 5 L / min, duration 30 seconds), and the surface hardness after cooling is greater than or equal to HRC 25.

[0042] Step S5: quality closed-loop detection Ultrasonic flaw detection: use a flaw detector with a probe frequency of 5 MHz, scan along the weld longitudinal direction (speed 120 mm / s), and the defect echo amplitude less than or equal to 20% is judged to be qualified. Mark the defect area and recheck after repair until qualified.

[0043] Vibration stability verification: install a vibration sensor, apply a sinusoidal vibration with a frequency of 10 Hz and an amplitude of 0.15 mm, and last for 30 minutes. Monitor the displacement of the riveting part to be less than or equal to 0.05 mm, and the rivet pre-tightening force loss after vibration to be less than or equal to 5%.

[0044] Using the above process, the whole-process standardized operation is realized, and steps S2-S4 can shorten the processing flow and improve the processing efficiency; modular segmented replacement reduces material waste, and the pre-tightening force of the hot riveting anchor is improved.

[0045] Example 2

[0046] Based on example 1: Among them, S21 spot welding path planning: dynamically adjust the spot spacing according to the plate deformation (formula S=150+10t); S22 dynamic welding fixation: single spot welding time of pulse spot welding machine is less than or equal to 0.5 seconds (current 8000A); S23 error compensation drilling: real-time monitoring of drilling deviation, adjusting the speed (270-290 rpm); S24 spot cleaning: carbon arc gouging removes the welding spot, polishing to Ra≤6.3μm; through this process, the spot avoids the drilling path, the hole deviation is reduced, and the short-time high-energy spot welding reduces the heat affected zone and the plate deformation.

[0047] Among them, S31 stress-oriented cutting: finite element analysis determines the low-stress cutting line; S32 adaptive bevel: bevel angle matching plate thickness (35°±2°), thick blunt edge 10-15% plate thickness; S33 heat input control welding: segmented back welding (each segment ≤80mm), interlayer cooling to ≤150℃; S34 stress release: post-welding hammering weld + local annealing (300℃×30min); This kind of process can improve the precision of cutting position control, and at the same time, segmented back welding is used to reduce the welding deformation amount of back welding.

[0048] Among them, S41 rivet heating: intermediate frequency induction heating to 630-670℃ (infrared temperature monitoring); S42 pose leveling: hydraulic jacking 20-30mm, laser level control flatness ≤1mm / m; S43 multi-stage riveting: pre-tightening (30J)→forming (50J)→finishing (20J) three times impact; S44 post-processing: detect rivet head height ≥8mm, spray cooling overheated area, using this kind of process, three-stage riveting makes the pre-tightening force distribution uniform, reduces the fluctuation rate in the processing process, and spray cooling avoids thermal damage and improves the hardness around the rivet; In the specific processing process, the process parameters will also be optimized under high temperature working conditions; Step S1 pretreatment: after removing the oxide layer, spray high-temperature anti-oxidation coating (material: aluminosilicate, thickness 50μm), drying temperature 200℃, time 30 minutes.

[0049] Step S33 welding: using high-temperature resistant welding wire (model: ER309L), increasing the protective gas flow to 18L / min, and widening the upper limit of interlayer temperature to 180℃.

[0050] Step S44 riveting post-processing: inert gas cooling (nitrogen flow 10L / min) instead of spray cooling to avoid high-temperature oxidation.

[0051] Example 3

[0052] Based on examples 1 and 2: Among them, in step S5: the weld detection uses ultrasonic flaw detection, wherein the probe frequency is 5MHz, the scanning frequency is ≤150mm / s, and the riveting vibration test amplitude limit is 0.15mm, using probe detection and amplitude quantification evaluation to improve the overall structural stability of the equipment; The following is the specific ultrasonic flaw detection refinement operation process of the application example: Equipment selection and parameter setting: Olympus EPOCH 650 ultrasonic flaw detector was used, with a dual-crystal focusing probe (model: 5P10x10K2), frequency 5 MHz, focusing depth 10 mm. The scanning frequency was set to 120 mm / s (≤150 mm / s), the gain was adjusted to 60 dB, the beam angle was 70°, and the full thickness of the weld was ensured to be covered.

[0053] Detection path planning: Three parallel scanning paths were set along the longitudinal direction of the weld (centerline and two sides offset ±5 mm), and a zigzag path with a spacing of 20 mm was set transversely to cover the weld and heat-affected zone. An encoder (model: Wenglor MLWL122) was used to record the probe position, with a positioning accuracy of ±0.5 mm.

[0054] Defect judgment criteria: Defects with echo amplitude exceeding the reference wave height by 20% were marked as unqualified (such as pores and slag); cracks were directly judged as major defects and needed to be repaired and rechecked.

[0055] Data storage and analysis: The flaw detection data was uploaded to the analysis software (OmniPC) in real time to generate C-scan images (resolution 0.1 mm x 0.1 mm), and the defect position and size were marked (length > 2 mm needed to be repaired).

[0056] Quantitative evaluation of riveting vibration test: Test equipment and parameters: An electromagnetic vibration table (model: LDS V964) was used, with a maximum thrust of 10 kN and a frequency range of 5-2000 Hz. A sinusoidal vibration load was set: frequency 10 Hz (simulating the working frequency band of the coal car), amplitude 0.15 mm, duration 60 minutes.

[0057] Sensor arrangement and data acquisition: Three groups of three-axis acceleration sensors (model: PCB356A16) were installed in the riveting area, with a sampling frequency of 1 kHz, covering the center and edge of the rivet (spacing 50 mm). Vibration displacement (laser displacement sensor, model: Keyence LK-G5000, accuracy ±0.001 mm) and pre-tightening force decay (strain gauge patch, model: HBM 1-LY11) were monitored synchronously.

[0058] Stability judgment criteria: During vibration, the rivet displacement was ≤0.05 mm (peak value), and the pre-tightening force loss was ≤5%; after vibration, the rivet head height was ≥8 mm, and the plastic deformation was controlled within 1.2-1.5 times the diameter (e.g. original diameter 20 mm, deformed 24-30 mm).

[0059] Data visualization and report generation: The vibration acceleration frequency spectrum (resolution 0.5 Hz) and displacement-time curve were generated by LabVIEW software, and the resonance frequency point was marked (which needed to be avoided in the 10-15 Hz working frequency band of the coal car).

[0060] The embodiment is implemented in a coking plant coal support plate maintenance project, and specific effects are as follows: Detection accuracy is improved: The ultrasonic flaw detection defect detection rate is increased to 99.2%, and the misjudgment rate is reduced to 0.8%; In the vibration test, the standard deviation of rivet displacement is reduced from 0.08 mm of the traditional process to 0.03 mm.

[0061] Structural stability is enhanced: After the coal support plate is continuously worked for 6 months after maintenance, the rivet pre-tightening force retention rate is ≥95%, and there is no loosening phenomenon; The coal loading precision deviation is reduced from ≥5 mm before maintenance to ≤1.5 mm (in line with the JB / T 3055-2016 standard).

[0062] Efficiency and cost are optimized: The quality detection time is shortened from 8 hours of the traditional process to 3 hours; The rework rate is reduced from 5.6% to 1.0%, and the maintenance cost is saved by 28%.

[0063] In the above embodiments, the description of each embodiment has its own emphasis, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0064] The high-precision maintenance method of the coal support plate of the stamp-charging coke oven charging car provided by the embodiments of the present application is described in detail above, and specific examples are applied to describe the principles and implementation modes of the present application. The above embodiment is only used to help understand the technical solutions and core ideas of the present application; those skilled in the art should understand that the technical solutions recorded in the above embodiments can be modified, or some technical features can be replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A high-precision maintenance method for the coal supporting plate of a ramming coke oven coal charging car, characterized in that: include: Step S1: Pretreatment of old and new boards: removing the oxide layer and contaminants on the contact surface between the upper old board and the lower new board; Step S2: Drilling and positioning: temporarily fix the new and old plates by spot welding and then drill holes simultaneously; Step S3: Modular segmented replacement: cutting the coal supporting plate into a wear section and a retaining section, removing the wear section and welding a new plate; Step S4: Thermal anchoring: heating the rivets and adjusting the position of the coal supporting plate to complete the riveting; Step S5: Closed-loop quality testing: Perform non-destructive testing and vibration stability verification on welding and riveting parts.

2. The high-precision maintenance method for the coal supporting plate of the ramming coke oven coal charging car according to claim 1 is characterized in that: The step S2 further includes the following specific steps: Step S21: spot welding path planning: determining the welding spot spacing according to the plate deformation to avoid the subsequent drilling area; Step S22: Dynamic welding fixation: Use a pulse spot welder to apply short-time high-energy welding, with a single-point welding time of ≤0.5 seconds: Step S23: Error compensation drilling: real-time monitoring of drilling deviation during drill feeding, and compensation of errors by adjusting the rotation speed; Step S24: Welding spot removal and trimming: Use carbon arc gouging to remove the welding spots and grind them to a surface roughness of Ra ≤ 6.3 μm.

3. The high-precision maintenance method for the coal supporting plate of the ramming coke oven coal charging car according to claim 1 is characterized in that: The step S3 also includes the following specific steps: Step S31: stress-guided cutting: determine the low-stress cutting position through finite element analysis, and the cutting path is 1 / 4 to 1 / 3 of the plate length from the end; Step S32: Adaptive groove processing: matching the groove angle according to the plate thickness, and the blunt edge thickness is 10% to 15% of the plate thickness; Step S33: Heat input controlled welding: adopt segmented back-welding process, each welding section length is ≤80mm, and the interlayer cooling temperature is ≤150℃ before continuing welding; Step S34: Welding stress release: hammer the weld immediately after welding and perform local annealing.

4. The high-precision maintenance method for the coal supporting plate of the ramming coke oven coal charging car according to claim 1 is characterized in that: The step S4 also includes the following specific steps: Step S41: Rivet thermodynamic treatment: medium frequency induction heating of the rivet to a red hot plastic state; Step S42: coordinate posture adjustment: lift the coal support plate by 20-30 mm using a hydraulic jack, and use a laser level to provide real-time feedback for leveling; Step S43: multi-stage impact riveting: the pneumatic riveting gun performs three-stage impacts of pre-tightening, forming, and finishing in sequence; Step S44: Post-riveting processing: Check that the rivet head height is ≥8 mm and spray cool the overheated area.

5. The high-precision maintenance method for the coal supporting plate of the ramming coke oven coal charging car according to claim 2, characterized in that: The step S2 further includes: the welding point spacing in step 21 is positively correlated with the plate thickness, which specifically satisfies the relationship: welding point spacing S (mm) = 150 + 10 × plate thickness t (mm), where the value range of t is 15≤t≤25mm.

6. The high-precision maintenance method for the coal supporting plate of the ramming coke oven coal charging car according to claim 3, characterized in that: The step S3 also includes: the segmented de-welding in step 33 adopts CO2 gas shielded welding, the shielding gas flow rate is 15±2 L / min, and the welding wire dry extension length is 12~15 mm.

7. The high-precision maintenance method for the coal supporting plate of the ramming coke oven coal charging car according to claim 4, characterized in that: The step S4 also includes: the laser leveler leveling accuracy in step 42 is 0.1 mm / m, the jacking speed is ≤ 2 mm / s, and the pressure is maintained for 5 minutes after the jacking is in place.

8. The high-precision maintenance method for the coal supporting plate of the ramming coke oven coal charging car according to claim 1, characterized in that: In step S5: the weld detection adopts ultrasonic testing, wherein the probe frequency is 5 MHz, the scanning frequency is ≤150 mm / s, and the amplitude limit of the riveting vibration test is 0.15 mm.

9. The high-precision maintenance method for the coal supporting plate of the ramming coke oven coal charging car according to claim 3, characterized in that: In step S31, the finite element analysis uses software to establish a three-dimensional model with a grid size of 5mm×5mm. The loading condition simulates the actual force on the coal supporting plate to determine that the stress concentration coefficient of the cutting path is ≤1.2 and the maximum residual stress of the retained section after cutting is ≤120MPa.

10. The high-precision maintenance method for the coal supporting plate of the ramming coke oven coal charging car according to claim 4, characterized in that: The impact energies of the multi-stage impact riveting in step S43 are: 30J in the pre-tightening stage, 50J in the forming stage, and 20J in the finishing stage. The total number of impacts is 3 times, the interval between adjacent impacts is ≥10 seconds, and the plastic deformation of the rivet is controlled within the range of 1.2 to 1.5 times the diameter.

Images