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Common fault causes and solutions of COP1238K rock drill

FmribtAdmin — Fri, 15 Sep 2023 08:44:32 +0000

INTRODUCTION

The COP1238K rock drill is a hydraulic rock drill produced by Epiroc Company. Because it is relatively cheap and can meet production needs, it has been put into large use in certain mines in recent years. At the same time, failures caused by improper use or repair also occur frequently, which not only affects the efficiency of the rock drill, but also increases the cost of using the rock drill. To this end, many scholars have done a lot of research and summarized a lot of maintenance and use experience. On this basis, this article will combine common faults, analyze the causes of the fault, and propose solutions. It is hoped that it will have positive significance for the correct use and cost control of rock drills in the future.

1. Front end of rock drill

The front end of the rock drill is mainly composed of shell, guide sleeve, flushing head, thrust ring, hydraulic plate and other parts. It has two main functions. One is to guide and support the rotation of the drill tail; the other is to introduce water from the water pump into the drill tail and provide it to the drill pipe.

1.1 Wear of guide sleeve and thrust ring

The copper guide sleeve is generally not easy to wear when lubricated with drill tail oil. If the guide sleeve wears repeatedly in a short period of time (which needs to be judged based on the actual situation), you need to check whether the drill tail lubricating oil channel of the rock drill is blocked. If it is blocked, The rock drill needs to be disassembled and repaired.

When the rock drill drills holes upward, rock debris will also flow into the front end of the rock drill along the drill pipe, accelerating the wear of the guide sleeve. The medium-deep hole rock drilling rig used in a mine has a lot of upward drilling operations, so the guide sleeve wears much faster than the horizontal excavation rig. Installing a waterproof cover at the drill tail can better prevent debris from entering and extend the service life of the guide sleeve.

The thrust ring bears the axial impact force and radial friction force of Shank Adapter. If the wear degree at the contact position between the thrust ring and the drill tail spline exceeds 1mm, it needs to be replaced. The thrust ring is also lubricated with lubricating oil. If it is replaced frequently in a short period of time, you need to pay attention to whether the lubricating oil channel is blocked.

1.2 Water leakage from front end of rock drill

Worn front water seal can cause water leakage. The water seal is a 4-way Y-shaped seal, which not only prevents water leakage, but also prevents debris from entering. If water leakage occurs, the water seal should be replaced immediately, otherwise the front end of the rock drill will be damaged and the eye entry speed will be affected.

A cracked flush head can also cause water leakage from the front. There are two main reasons for the rupture of the flushing head. First, the operator has been dry drilling for a long time. When the operator cannot unload the drill pipe, he will start the impact vibration drill pipe. At this time, the drill pipe does not push against the rock, and most of the force is concentrated on the flushing head. Doing this for a long time will cause the flushing head to break; the second is caused by corrosion.

2. Gear box

The gearbox consists of a transmission shaft, a driving gear, a driven gear, a beating sleeve, a driving sleeve, a gearbox cover and a bearing. Its function is to transmit the power of the oil motor to the drill bit.

2.1 Drive sleeve wear

Under normal circumstances, the splines of the drive sleeve will be worn. When the spline exceeds 2mm, the drive sleeve needs to be replaced. The larger the diameter of the drill bit used, the faster the drive sleeve will wear. Excessive drill diameter will increase the load on the rock drill and cause the drive sleeve to rupture.

In the case of improper use, the drive sleeve will show abnormal wear. This is caused by a lack of grease in the gearbox or deterioration of the grease. Grease has the function of dissipating heat. If the temperature of the gearbox is too high, the copper bushing in the driven gear will rise above the step due to thermal expansion, and the drive sleeve will also rub against the thrust ring at the front end of the rock drill, eventually causing the end face of the drive sleeve to wear and tear. Debris generated by the friction of the drive sleeve will enter the inside of the rock drill, block the oil passage and even wear the cylinder part of the rock drill. Therefore, the grease in the gearbox needs to be resistant to high temperatures and should be replaced once a week.

2.2 The condom broke after being beaten

The beating sleeve is located at the end of the drill tail and the front end of the buffer piston, and transmits the recoil force of the drill tail to the buffer piston. Under normal circumstances, the contact position between the beating sleeve and the end of the drill tail needs to be replaced if the wear exceeds 1mm.

During an impact, the energy of the impact piston is transmitted to the drill tail. The drill tail transmits the energy to the back of the rock through the drill pipe, and the remaining energy is transmitted to the buffer piston through the beating sleeve. Frequent dry driving or oil leakage from the buffer piston seal may cause the beating sleeve to rupture. If the pressure gauge shows normal pressure but the rock drill enters the hole slowly, you need to disassemble the front end and check whether the beating sleeve is damaged.

2.3 Rotary pressure is too high when idling

When the rock drill is idling, the pressure is generally below 5MPa. If the pressure is high, there are two reasons if the pressure regulating valve is normal. First, there is no grease in the gear box, which is prone to wear of the drive sleeve; second, during the installation of the gear box, the preload force of the cylindrical roller bearing in the gear box is not grasped, and the adjustment pad is placed too much, which presses the bearing. If it is too tight, the problem of excessive pressure during idling will also occur. When assembling the gear box, special tools should be used to tighten the gear box cover. The tightening torque of the tool is 200N·m. Use a feeler gauge to measure the gap between the gearbox cover and the gearbox, and control the gap to 0.15~0.20mm by increasing or decreasing the adjustment pad. Only then can the gearbox be considered correctly installed.

3. Intermediate body and cylinder

The intermediate body and cylinder body are mainly composed of buffer piston, impact piston, front guide sleeve, rear guide sleeve, reversing valve and other parts. Both the intermediate body and the cylinder block can be understood as a form of oil cylinder.

3.1 Wear of buffer piston and intermediate inner cavity

The buffer piston also moves axially in the rock drill, and its surface will be worn by the two seals. When the wear degree exceeds 0.1mm, it needs to be replaced. If the buffer piston is severely worn and is not replaced, the buffer piston and the inner cavity of the intermediate body will rub against each other. At this time, the entire intermediate body will be scrapped, causing huge losses, as shown in Figure 3. When assembling the buffer piston, the intermediate body should be placed horizontally, apply hydraulic oil to the intermediate body cavity and the surface of the buffer piston, and press the buffer piston vertically. If you encounter large resistance or there is obvious rebound force when knocking, you should stop pressing immediately and check whether the buffer piston is placed vertically to avoid damage to the intermediate cavity.

3.2 Impact piston breaks

A broken impact piston is a very serious problem. In actual use, the operator cannot immediately judge after the piston breaks. If the impact continues, the broken piston and debris may wear the cylinder, causing the rock drill cylinder to be scrapped. Therefore, in daily maintenance, we should try our best to avoid this situation.

There are two main reasons for the fracture of the impact piston. One is the uneven wear of the two guide sleeves at the front and rear ends of the cylinder; the other is the different tightening torques of the three fixing bolts of the rock drill. When the gap between the guide sleeve and the piston exceeds 0.06mm, it needs to be replaced. It is important to note that the order should also be paid attention to when removing and assembling the impact piston. When dismantling the rock drill, you should first remove the impact piston, and then remove the fixing bolts of the rock drill. When assembling the rock drill, the three fixing bolts should be tightened to a torque of 300N·m, apply hydraulic oil to the piston, and slowly screw it in from the rear end. If resistance is encountered, the installation should be stopped immediately and the cause should be found. This is to ensure that the impact There will be no eccentricity after the piston is installed.

3.3 Impact piston cavitation

During an impact, if the hydraulic oil cannot be replenished, the vacuum generated by the cylinder will suck out the air mixed in the hydraulic oil, forming bubbles. The bubbles burst under high temperature and pressure and eroded the surface of the impact piston, causing cavitation. When cavitation occurs in the impact piston, its rough surface will accelerate the damage of the seal during the friction process with the seal, thereby causing oil leakage in the rock drill.

Regularly checking the accumulator pressure can effectively prevent cavitation of the impact piston. The two accumulators of the COP1238K rock drill are connected to the high-pressure oil circuit. When one of them fails to work, the other can still play a certain role. When it is found that the main oil return pipe of the rock drill is beating abnormally, it is necessary to add nitrogen or replace the accumulator. The nitrogen charging pressures of the two accumulators are 8 to 10 MPa respectively.

4. Precautions for use and maintenance

The rock drill is a precision core component of the rock drilling rig. The following points should be noted during use and maintenance:

(1) Make sure the hydraulic oil is clean and replace the hydraulic oil filter element regularly. When replacing the oil pipe and adding hydraulic oil, you should also be careful not to mix mud, gravel, etc.;

(2) Wearing parts such as the guide sleeve and water seal at the front end of the rock drill must be replaced in time;

(3) Regularly check the accumulator pressure and lubricating oil passage, regularly add grease and tighten the fixing bolts according to the torque requirements;

(4) After dismantling the rock drill, focus on checking the wear degree of the beating sleeve, drive sleeve, buffer piston, driven gear and other parts, and check the matching clearance between the impact piston and the front and rear end guide sleeves;

(5) When assembling the rock drill, attention should be paid to the installation sequence of the impact piston, the pretightening force of the gear box, and the tightening torque of each bolt of the rock drill.

5. CONCLUSION

By analyzing the causes of various failures of the COP1238K rock drill, suggestions for use and maintenance were put forward respectively, which provided theoretical support for preventing operators from improperly using rock drills and improving the skill level of maintenance personnel.

Common fault causes and solutions of COP1238K rock drill最先出现在Fmribt。

Down-The-Hole Drilling Rigs

FmribtAdmin — Fri, 15 Sep 2023 08:35:18 +0000

INTRODUCTION

With the rapid development of social economy, the demand for mineral resources has increased year by year, so mining facilities have also received widespread attention. It mainly briefly explains the working principle and structure of down-the-hole drilling rigs, analyzes common faults of down-the-hole drilling rigs and corresponding solutions, and also analyzes the maintenance measures of down-the-hole drilling rigs in open-pit mines, in order to ensure the safety and efficiency of mining. run.

Analysis of common faults of down-the-hole drilling rigs

Failures that often occur during the drilling process mainly include: relatively severe swing of the drill frame and overload problems of the rotary motor, which will lead to abnormal drilling; damage to the rotary mechanism, reducer bearings, and gear teeth, etc. As a result, the rotary load is too large and the coupling fails, causing the rotary mechanism to be unable to operate; when the drill is severely stuck, the lifting device cannot lift properly; due to damage to the seal or wear of the outer ring of the bearing, the sealing effect is not good, resulting in joints Air leakage and pressure relief phenomenon; the drilling rig manipulator cannot clamp the drill pipe, mainly because the chuck is worn or the manipulator claws are deformed; the main cause of walking problems may be that the bearings of the reducer are damaged or the track joints are worn or the track Stretching, pressure relief of the track tensioning cylinder, etc.; failure of the connecting and unloading rod components may be due to misalignment of the upper and lower positioning sensors of the drill rod magazine, unsynchronization of the upper and lower manipulator cylinders, bending of the drill rod, etc.; impactor frequency generation Abnormality. The reason for this abnormality is that the assembly gap between the cylinder and the piston is unreasonable, resulting in the gap between the sleeve and piston being too small or too large.

Working principle and structure of down-the-hole drilling rig

1． DTH HAMMER

Hammer has two exhaust structures, namely center exhaust and side exhaust. This article mainly introduces the center exhaust impactor. The exhaust gas and part of the compressed air generated by the work enter the bottom of the drill hole through the middle hole channel of the drill bit. In the working state, the impactor piston continuously impacts the drill bit, providing a steady stream of impact energy to squeeze the rock, and the cylinder is not subject to impact load. The main working principle of the impact stroke is: at the beginning, the piston is in the extreme left position, and part of the compressed air enters the cylinder through the valve cover, pushing the piston to move. At this time, the spline groove of the bushing is closed, the pressure continues to rise, and the rear end hole of the piston leaves The pressure of the air distribution rod decreases, and then impacts the drill tail at high speed, and the impact stroke ends.

2. slewing mechanism

As one of the important working parts of the down-the-hole drilling rig, the rotary mechanism mainly transports compressed air and drives the rotation of the impactor. The main working parts of this structure are the rotary reducer, rotary machine and air supply gyrator, which are connected as a whole through couplings and bolts and fixed on the sliding plate of the drill frame guide rail.

3． Slag discharge system

The drilling process will produce a large amount of cuttings and dust. If the slag is not discharged in time, it will affect the drilling work. Currently, there are two methods: dry slag discharge and wet slag discharge. The dry slag discharge uses the action of compressed air to discharge rock debris, and the wet slag discharge uses the effect of Feng Shui mixture to discharge. The quality of the slag discharge system is related to the working effect and service life of the drilling tool.

3. Troubleshooting Countermeasures

1． Countermeasures during the drilling process

During the drilling process of down-the-hole drilling rigs in open-pit mines, the sound of the drilling rig should be monitored at all times to distinguish vibration and abnormal noise conditions. When dealing with loose rock formations and severe cuttings falling off, if the drilling speed changes significantly and rocks are falling off at the same time, you should stop immediately, lift the drilling tool out of the borehole, and remove it beforehand. The adjusted adhesive is placed in the borehole. The combined action of the pressure and the drill pipe will cause the adhesive to adhere to the loose borehole wall, ensuring the smooth progress of the drilling work. The most important thing to pay attention to in this link is the stuck situation of the drill. Once the stuck phenomenon occurs, it will have a huge impact on the drilling speed and even cause damage to related parts. For stuck drill faults, do not act too hastily, otherwise the fault will amplify, such as rupture of the rotary motor oil pipe, toothing of the rotary gear, damaged bearings, etc. It should move up and down slowly, alternating positive and negative actions.

2. Things to note when stopping and moving

During the process of drilling another hole position, the impactor can no longer provide air pressure at this time, and then stop the ventilator. The drilling tool cannot be rotated. The drilling tool cannot be lifted to the top at once. It should be allowed to rise slowly. Coordinate all links and do not change the sequence. If the gas supply system is shut down prematurely, the speed of lifting the drilling tool will be too slow, and the cuttings and ash layer will easily wrap the drilling tool, causing the drill to get stuck. Go to the corresponding drilling hole position, adjust the operating parameters before operating.

4. Maintenance of down-the-hole drilling rigs in open-pit mines

When loading and unloading drill pipes, the different rotating arms of the drill pipe manipulator should be structurally concentric and synchronized and should not be deformed; ensure that the rotation angle of the drill pipe magazine is uniform and accurate, and that too many objects should not be accumulated in the tray of the drill pipe magazine. Dust; it is necessary to ensure that the manipulator slips are sufficiently tightened. Once the slips are worn, they need to be replaced in time to prevent the drill pipe from falling on site and causing safety accidents; when disassembling the drill pipe, the unloading cylinder is stuck The claws should block the main and auxiliary drill pipes, and the air supply system cannot be opened at this time. When raising and lowering the drilling rig, the rope releasing speed of the wire rope should be smaller than the free falling speed of the drilling rig, otherwise the wire rope will become knotted. When the drill frame is lifted to the appropriate working position, it should be reinforced. Otherwise, the swing of the drill frame during drilling will cause the drilling angle to change, and the drilling quality cannot be guaranteed. For the rotary air supply system, in-shift inspections should be strengthened to avoid loosening of connections. Particular attention needs to be paid to the meshing of the gears in the reducer. Once abnormal noise occurs and the rotation is inflexible, work must be stopped immediately and a specialized maintenance team must be dispatched. Personnel are required to open and inspect the internal components to see if any parts are damaged. The axial runout of the hollow spindle should be within 0.8mm, and the axial runout of the gear should be within 0.3mm. If it exceeds the range, the relevant parts must be repaired in time. Tighten and adjust. When air leakage occurs in the air supply system, the sealing condition should be checked immediately, and the sealing rings and severely worn bearings should be replaced if necessary. Maintenance of wire ropes, sky wheels and ground wheels: During the drilling process, professional maintenance personnel should adjust the tightness of the wire rope. The drilling stroke is closely related to its tightness.

In short, when using down-the-hole drilling rigs, great attention should be paid to the use, management and maintenance of mining equipment. In this way, we can improve the technical level of domestic mining rock drilling equipment management, better utilize the effective life of mining equipment, continuously improve the comprehensive benefit level of mines through scientific management methods, ensure the safe and efficient production of mineral mining enterprises, and better Escort the energy saving and efficiency improvement of mining enterprises.

Down-The-Hole Drilling Rigs最先出现在Fmribt。

overhaul of rock drilling rigs

FmribtAdmin — Thu, 14 Sep 2023 03:46:08 +0000

1 Overhaul timing and overhaul confirmation procedures

1.1 Timing of overhaul

The overhaul time of rock drilling rigs is generally after 8 to 10 years of operation, and the rock drilling impact time generally reaches 15,000 to 20,000 hours. The overall technical performance, drilling efficiency and accuracy decrease greatly, and the downtime for maintenance increases. When repairs are no longer sufficient to maintain the technical performance of the equipment, the user can apply for overhaul.

1.2 Overhaul confirmation procedure

The overhaul confirmation process implements a three-level technical appraisal system, that is, preliminary appraisal by the grassroots team, review by the business department, and review by the superior authority. The maintenance team of the grassroots unit will conduct technical appraisal without disassembly, submit an application for overhaul, and submit it to the equipment management department at the same level for review. The equipment management department shall make a horizontal comparison based on the equipment requirements for annual construction tasks, the inventory of equipment of the same type, and the technical status of the equipment to determine whether the equipment is suitable for overhaul, and report it to the superior authority for filing, waiting for the superior authority to issue an annual equipment overhaul plan.

After the equipment repair plan is issued, the equipment management department coordinates professional maintenance personnel to conduct detailed disassembly, clarify repair parts and components, and compile a detailed spare parts demand plan, outsourcing processing plan, and oil-attached auxiliary material plan. Based on the overhaul equipment application plan, the superior authority promptly organizes on-site review by professional forces, studies and determines the repair level and repair method, and finally approves the repair plan.

2. Preparation before repair

2.1 Compilation of technical data

Before repairing equipment, prepare a history of use and repair of the equipment, and collect as much technical information as possible about the model’s operating instructions, parts manuals, repair manuals, and overhaul files for similar equipment over the years. Adequate preparation of technical data is the basis for standardized equipment maintenance and is also the technical legal basis. Referring to the overhaul files of other equipment can enable us to accumulate necessary experience and avoid detours. It is necessary to ask the technical service provider to provide as detailed technical information on the equipment as possible, especially repair standard information. In addition, the internal training materials provided by the manufacturer are also a good reference source for repairs, which can enable us to gain a deeper understanding of the working principle of the equipment or assembly during the disassembly process.

For foreign language repair information on key parts of imported equipment, specialized technical personnel should be organized to translate and sort out the information, and should be repeatedly checked with equipment operators to prevent translation errors. The original text and translation should be numbered and archived and properly kept.

2.2 Plan preparation

A detailed maintenance plan is the basis for a successful equipment overhaul. It must be a complete plan based on equipment disassembly, involving professionals, and technically executable. The overhaul experience over the years proves that without dismantling the equipment, it is unscientific to rely only on the description of the operator, the maintenance experience of the appraiser, and copying the overhaul list of the same type of equipment in previous years. In this way, a secondary appraisal is likely to occur after the equipment is disassembled. The maintenance list needs to be added, deleted, or modified. If the scope of the increase is large, a second spare parts bidding will be required. This not only increases the workload of the agency, but also greatly extends the repair cycle.

The maintenance plan should include: ① Determine the maintenance location and location; ② Define the overhaul management organizational structure and division of responsibilities, and identify the majors and participants; ③ Clarify the repair process and precautions; ④ Attach an appraisal and three certificates approved by the superior Plans: Engineering equipment technical appraisal form and spare parts demand plan, outsourcing maintenance and processing plan, oil-attached auxiliary materials plan.

2.3 Repair site preparation

Rock drilling rigs are relatively complex large-scale equipment, and the maintenance site cannot be too simple. The area of the maintenance site must meet the basic disassembly and assembly needs. Generally, the main workshop is not less than 100m², the space height is not less than 6m, and it is equipped with a truss truck of ≥5t.

In order to ensure work efficiency, in addition to basic tools and equipment, special repair and monitoring tools are also essential. For example, hydraulic ejector specially used to remove pins, complete set of rock drill repair tools, hydraulic test bench, complete set of oil pipe processing equipment, etc. In order to meet the needs of large-area cleaning and paint removal, high-pressure cleaning water guns and pneumatic sandblasting machines with a pressure of ≥20MPa can be configured.

2.4 Training of participants

Rock drilling rig overhaul is a specialized activity, which is different from daily repairs and requires higher technical standards. Participants must undergo systematic training before repairs. The specific training method can coordinate the training of technical service providers, or arrange training for internal key personnel. The purpose of the training is to let everyone understand the basic procedures of repair plans and overhauls, become familiar with various technical materials, master the working principles of equipment, understand their responsibilities and positioning, and prevent the occurrence of buck-passing.

Learning by doing is an effective way to improve yourself in practice. As a trainee, you can gain knowledge from primary sources such as equipment manufacturers, technical service providers and professional books to solve practical maintenance problems encountered. Units can also take advantage of the overhaul opportunity to select operators or repairmen to participate in the overhaul work to integrate training and quickly improve the repair capabilities of front-line personnel so that they can better use equipment and tap the potential of equipment efficiency. In principle, the captain of the aircraft must participate in the overhaul work throughout the entire process.

The training objectives for the participants are as follows: ① Be familiar with and understand the appearance of various mechanical components, hydraulic components, and electrical components installed on the equipment, match them with the system schematic diagram, and solve the problem of “what they are” ; ② You must understand the role of each component in the system and solve the problem of “what it does”; ③ Be clear about the internal structure and working principles of various components, and try to be as familiar as possible to solve the problem of “why”; ④ It is necessary to have a comprehensive understanding of hydraulic circuits, electrical circuits, and water and gas circuits, master the functions and interrelationships of each component in the circuit and system, and solve the “how” problem.

3. Control of key links in repair

3.1 Maintenance and replacement standards of each assembly

Overhaul must take reliability and safety as the main goals. In principle, the replacement of components is determined based on the service life recommended by the equipment manufacturer. Generally, the hydraulic pump must be replaced, and the valve parts must be inspected to determine whether to replace them. It is best to replace all hydraulic hoses in the system, replace all seals, and replace the filter elements of the filters at each location. All monitoring instruments such as pressure gauges and timers must be calibrated or replaced.

The working arm end is the focus of overhaul and must be replaced if it is eligible for replacement. Under normal circumstances, consumable and wearing parts must be replaced, such as the wear-resistant steel skin of the propulsion beam, rubber top plate, propulsion and return wire ropes, etc. The pusher beam must be replaced if it is bent. Even if the pressure monitoring of the hydraulic cylinder is qualified, all seals should be disassembled and replaced. All pins and pin sleeves at the arm end should be replaced, and the base holes of the pins should be inspected and repaired to their original dimensions.

The design life of the engine is generally longer than the life of the vehicle. The engine should be fully inspected and maintained during overhaul to ensure its reliability. The electrical system will be repaired depending on the normal working stability of the equipment, and all cables and main electrical control cabinets will be replaced if necessary. If the air compressor and high-pressure water pump have not been replaced in the early stage and have a history of maintenance, it is recommended to replace them with new ones.

Overhaul must adhere to concept innovation and cannot “repair the old as before”. It is necessary to upgrade the equipment or improve its functions in a timely manner depending on the degree of technological development. For example, the DCS1200 rock drilling control system adopted 20 years ago can be upgraded to the currently commonly used DCS1800 rock drilling control system; the rock drill is the core component of the rock drilling rig, and the COP1838ME rock drill was the standard machine more than ten years ago. model, it can also be upgraded to the more durable COP1838HD or COP1838HD+ rock drill.

For models that can be restored to their original accuracy requirements through maintenance methods, every effort should be made to ensure that they meet the original accuracy standards. For models that cannot be restored to original factory standards, some emphasis should be placed on them. For several indicators that are closely related, such as the stability of the pressure of the entire machine system, the accuracy of the drill arm positioning, the reliability of the electrical system, etc., more technical efforts should be invested to make them meet the minimum technical standards. For the repair of specific parts, a reasonable repair plan should be formulated based on the structural characteristics and accuracy of the workpiece to be repaired and combined with the on-site repair capabilities, and corresponding repair methods should be used for repair.

3.2 Pollution control during maintenance

There is a famous saying in the repair industry: “80% of hydraulic system failures are caused by contamination of hydraulic oil and hydraulic systems.” Practice has also proven that there are many cases of hydraulic system failure and shortened life due to oil contamination. For this reason During the entire maintenance process, attention should be paid to pollution control and management. Source blocking, cleaning and filtration are effective measures to control pollution in hydraulic systems. Equipment assembly should be carried out in the workshop as much as possible, and precision parts should be assembled in a relatively closed dust-free environment.

3.2.1 Scientific cleaning of hydraulic system

It is necessary to focus on the three stages of cleaning work: The first is cleaning before the equipment is dismantled. In the cleaning field, high-pressure water guns are used to comprehensively clean the entire machine to remove accumulated oil and dust inside and outside the vehicle body. The second is cleaning of hydraulic components and hydraulic systems before installation. Hydraulic components, hydraulic auxiliary parts and hydraulic systems must be carefully cleaned to remove remaining chips, abrasive grains, yarn ends, oil stains, welding slag, rust flakes, peeling paint and plating materials attached to the surface. In addition to soaking and cleaning with kerosene, diesel or aqueous cleaning fluid, a more efficient ultrasonic cleaning machine can also be used to clean components with complex structures. The third is the cleaning of hydraulic components after they are installed in the system. Before commissioning, the hydraulic system circuit must be cleaned to remove dirt that entered the system during circuit installation and contamination from parts that have not been cleaned. At present, methods such as gravity cleaning, working fluid circulation cleaning and no-load operation cleaning are generally used.

3.2.2 Pressure hydraulic oil pipes must be prevented from contamination

When it is necessary to press a complete set of hydraulic oil pipes on site, while ensuring the quality of the press, it is necessary to prevent the outer rubber debris of the hydraulic oil pipe from remaining in the pipe. Hydraulic oil pipes should be flushed with a special pipe flusher, and rubber caps should be used to immediately seal both ends of the pipes, and they should be neatly sorted on the shelf for later use.

3.3 Spare parts management

Spare parts used for overhaul are specially purchased according to the demand plan. The spare parts purchased for each overhaul of rock drilling rigs are more than one million yuan. The value of the goods is high, so special parts should be managed exclusively. Under normal circumstances, it is managed by the maintenance equipment warehouse in the work area. When the overhaul site is far away from the maintenance equipment warehouse in the work area, a special storage space should be set up nearby and designated personnel should be arranged for safekeeping. Spare parts management at the overhaul site focuses on three aspects:

3.3.1 Arrival acceptance process

After the spare parts are notified of arrival, the on-site repair team must form an acceptance team together with the installation and management personnel in the work area, warehouse custodians, etc., and verify the parts one by one based on the relevant terms of the procurement contract and the relevant information on the parts list, and resolutely prevent parts from being shoddy or shoddy. Makeshift use, etc. After the parts pass the inspection, the acceptance team jointly signs the acceptance minutes and signs the parts arrival list for approval.

3.3.2 Storage and storage process

The circulation cycle of overhaul spare parts is generally within one year, and a special area should be set up in the warehouse for storage on special shelves, strictly separated from other maintenance equipment. Spare parts that pass the inspection should be sorted into categories in a timely manner, stored on shelves, and kept in a clean state. Maintenance team personnel should be on-site to assist when placing them. All overhaul spare parts should be marked with models, specifications, and usage parts to facilitate maintenance personnel to find them.

3.3.3 Receipt and delivery process

The principle of assembly on the same day of use must be adhered to, and spare parts shall not be stored at the maintenance site. The spare parts assembly record of the day must be consistent with the spare parts delivery record.

3.4 Old parts management

All old parts should be classified, stored centrally, labeled and managed on shelves to facilitate supervision and later review. It is necessary to continue to repair and recycle old parts that have continued use value. They can be used as spare parts in daily repairs and enter the circulation and use of normal spare parts.

3.5 Registration Statistics

The overhaul and repair cycle of rock drilling rigs is long, involves a wide range of specialties, and involves many repair and replacement parts. It is necessary to strengthen the registration and statistics work during the overhaul process in order to strengthen the maintenance plan progress management and trace the source of later problems. The replacement and debugging of components and seals during overhaul should be recorded and archived in detail. Under normal circumstances, registration statistics need to be completed, including equipment overhaul work log, disassembly and inspection record form, spare parts arrival and acceptance list, spare parts entry and exit registration form, outsourcing processing and repair acceptance form, assembly process registration form, and remaining spare parts registration after repair Table, used parts registration form, repair and waste spare parts list, etc.

4. Post-management after completion

After the repair team completes the overhaul work, documents and materials should be archived in a timely manner. Cooperate with the equipment overhaul and acceptance team of the superior agency to complete the inspection and acceptance of the equipment, and promptly carry out on-site rectification of the problems found.

When it is delivered to the construction site for use, in addition to explaining in detail the precautions for using the equipment after overhaul, the corresponding complete set of maintenance process data must also be handed over. The upgrading and transformation parts of the equipment should be highlighted, and the original parts manual should be supplemented and improved. Repeal parts, change parts, and add new parts. During the trial operation, the maintenance team must do a good job in early tracking of equipment failures, handle them promptly, and try to shorten the time from trial operation to stable operation of the equipment. The management of the subsequent fault handling process should be regarded as part of the overhaul work. After the overhaul work is completed, all process data should be bound into a volume and archived by the equipment management department.

overhaul of rock drilling rigs最先出现在Fmribt。

Aluminum & Aluminum Alloys

FmribtAdmin — Tue, 24 Nov 2020 04:45:06 +0000

INTRODUCTION

Aluminum has a lighter specific gravity, smaller rebound during forming, relatively high strength, close to or exceeding high-quality steel, and good plasticity. When the product is formed more complexly, it is easier to control than stainless steel. It has excellent electrical conductivity, thermal conductivity, and resistance. It is corrosive, and the surface treatment processes of aluminum such as anodizing, wire drawing, and sandblasting are already very mature. Aluminum is also widely used in mobile phones. According to the processing method, aluminum alloys can be divided into deformed aluminum alloys and cast aluminum alloys. The numbers of aluminum and aluminum alloys are mainly divided into eight series. The different characteristics and applications of these aluminum alloy series will be introduced in detail below.

1000 SERIES ALUMINUM ALLOY (PURE ALUMINUM )

Among all series, the 1000 series contains the most aluminum, and the purity can reach more than 99.00%. The minimum aluminum content of the 1000 series aluminum plate is determined based on the last two Arabic numerals of the series. For example, the last two Arabic numerals of the 1050 series are 50. According to the international brand naming principles, the aluminum content must reach more than 99.5% to be a qualified product. The 1000 series aluminum has good formability and surface treatment properties, and has the best corrosion resistance among aluminum alloys. Its strength is low, and the higher the purity, the lower its strength. 1000 series aluminum materials are relatively soft and are mainly used for decorative or interior parts.

2000 SERIES ALUMINUM ALLOY (COPPER ALLOY)

It is characterized by high hardness but poor corrosion resistance. Among them, the copper content is the highest. The 2000 series aluminum alloy represents 2024, 2A16, and 2A02. The copper content of the 2000 series aluminum plate is about 3% to 5%.2000 series aluminum rods are aviation aluminum materials and are used as structural materials. They are currently not commonly used in conventional industries.

3000 SERIES ALUMINUM ALLOY (MANAGANESE ALLOY)

3000 series aluminum rods are mainly composed of manganese. The 3000 series aluminum alloys mainly represent 3003, 3105 and 3A21. The content is 1.0~1.5, which is a series with better anti-rust function. It is commonly used as tanks and tanks for liquid products, construction processing parts, construction tools, various lighting parts, and various pressure vessels and pipes for sheet processing. Formability, weldability and corrosion resistance are all good.

4000 SERIES ALUMINUM ALLOY (SILICONALLOY)

4000 series aluminum usually has a silicon content of 4.5% to 6.0%. The higher the silicon content, the higher the strength. The 4000 series aluminum rods are represented by 4A01 and the 4000 series aluminum plates belong to the series with higher silicon content. It has good liquid flow and little solidification shrinkage. It is a building material, mechanical parts, forging materials, and welding materials. It has low melting point, good corrosion resistance, heat resistance, and wear resistance.

5000 SERIES ALUMINUM ALLOY (MAGNESIUM ALLOY)

5000 series aluminum rods belong to the more commonly used alloy aluminum plate series. The main element is magnesium, and the magnesium content is 3% to 5%. The 5000 series aluminum alloy represents the 5052, 5005, 5083, and 5A05 series. It can also be called aluminum-magnesium alloy. The main features are low density, high tensile strength and high elongation. The weight of aluminum-magnesium alloy is lower than that of other series under the same area, and it is also widely used in conventional industries.

The most commonly used in mobile phones is 5052, which is the most representative alloy with medium strength. It has good corrosion resistance, weldability and formability, especially high fatigue strength and good seawater resistance. It is often used in products with high strength requirements. , but its coloring effect is less than ideal. It is suitable for sandblasting process, but not suitable for chemical sanding, matte surface, etc. It mainly uses casting molding and is not suitable for extrusion molding.

6000 SERIES ALUMINUM ALLOY (MAGNESIUM SILICON ALLOY)

The 6000 series aluminum alloy adds magnesium and silicon as alloy elements, which has high strength, corrosion resistance and heat treatment responsiveness. This aluminum alloy is widely used in structural parts and housings in aerospace, automotive and construction industries.

7000 SERIES ALUMINUM ALLOY (ZINC ALLOY)

7000 series aluminum alloy adds zinc as an alloy element and has good plasticity and welding properties. This aluminum alloy also has high strength and corrosion resistance and is often used to make structural parts and housings in aerospace and automotive fields.

8000 SERIES ALUMINUM ALLOY (OTHER ALLOYS)

8000 series aluminum alloy is a special type of alloy, including aluminum-tin alloy, aluminum-lithium alloy, aluminum-bismuth alloy, etc. These aluminum alloys have high strength, hardness and corrosion resistance and are widely used in high-performance structural parts and components in aerospace, automotive and electronics.

CONCLUSION

Different series of aluminum alloys have different characteristics and applications. Choosing a suitable aluminum alloy series can be determined according to specific engineering needs and application environment to achieve the best performance and effect.

Aluminum & Aluminum Alloys最先出现在Fmribt。