Use technology and safety management of truck tires
Abstract: According to the particularity of the use of truck tires and engineering equipment tires, the composition and structure of truck tires and engineering tires are analyzed, and a proposal is made Proper use and safe management methods of truck tires and engineering tires
2. Classification of engineering tires and applicable vehicle types
2.1 Classification of engineering tires
（ 1) According to the structure of the tire, it is divided into two types: tubeless and tubeless.
(2) According to the air pressure of the tires, they are divided into two types: high-pressure tires and low-pressure tires.
(3) According to the carcass structure, they are divided into bias tires and radial tires. For bias tires, the cord direction of the carcass is at an angle of 35° to the centerline (circumferential direction) of the tire. For radial tires, the direction of the cords of the carcass is at an angle of 90° to the direction of the tire's centerline. This distribution of the cords is very similar to the radials on the earth, so it is called a radial tire.
(4) According to the tread pattern, they are divided into ordinary pattern tires, mixed pattern tires and off-road pattern tires.
2.2 Types of Applicable Vehicles
The vehicles suitable for engineering tires are shown in Table 1. Vehicle Type Purpose Vehicle Name Requirements Characteristics Transport machinery Transporting soil, gravel, rock, coal, etc. Trucks Heat resistance and abrasion resistance
Resistance to impact, heat, and explosion Leveling machinery Leveling, road leveling machine Ground attachment Strength and operational agility (straight-line driving stability) Loading and dozing machinery Loading and dozing loaders Bulldozers Split resistance and wear resistance Road rollers Compaction rollers Oil resistance, split resistance and wear resistance 3 Reasonable tires Usage
3.1 Controlling tire temperature
The temperature of tires is extremely important for mining vehicles. Due to the load, the sidewalls are stretched and compressed, resulting in flexion and extension between the cords inside the carcass, friction between the tread and the road surface, and frequent braking when driving downhill, resulting in an increase in tire temperature. The increase in tire temperature has a great impact on the service life of the tire. It can cause the rubber to age and crack, reduce its physical function, cause separation between the cord layers, and shorten the service life.
In order to prevent the tire operating temperature from exceeding the regulations and causing early damage to the tire, foreign tire manufacturers have formulated methods for selecting tires according to the use conditions and the TKPH value of the tire. The TKPH value of a tire reflects the relationship between factors that cause the temperature of the tire to increase, indicates the tire heat generation limit, and is an indicator used to limit the tire's operating conditions. The purpose is to prevent the tires from experiencing high temperatures during use and extend their service life; the load and driving speed of the tires are limited to a range suitable for the tire's working capacity. Therefore, each size of tire has a certain load speed limit value, that is, the TKPH value. As long as you choose to use tires according to the TKPH value, you can effectively extend the service life.
3.2 Standard inflation pressure
Failure to inflate the tire according to the standard tire pressure is one of the main causes of early tire wear and damage. The level of tire pressure affects the service life of the tire.
(1) When the tire is used under low air pressure, it deforms radially, and the cords in the carcass produce large variable stress and deformation, which accelerates the fatigue damage of the cords. When rolling with low air pressure, the tire temperature will rise sharply, the relative sliding between the tire and the ground will increase, and the friction will generate more heat, which will increase the tire temperature, which will cause partial tire delamination and cord relaxation. When the air pressure is too low, the contact area between the tire and the ground increases and the contact pressure is reduced, resulting in greater tire shoulder wear and less tread wear.
When the tire tread recesses are under low air pressure, stones are most likely to penetrate into them, causing mechanical damage.
(2) Excessive tire pressure will overstretch the tire cords, accelerating the fatigue process of the cords. As the use time increases, the cords will be pulled off, causing early damage. . When hitting an obstacle, the carcass is prone to explosion. If the tire pressure is too high, the ground contact area becomes smaller, the tread pressure at the ground contact area increases, and the wear in the middle of the tread accelerates.
4. Scientific management of tires
Manage and use tires reasonably and correctly, maintain and repair tires in a timely manner, maximize the service life of tires, reduce transportation costs, and improve the business Economic benefits are of great significance.
4.1 Tire management
(1) Equip professionals and improve various management systems. The assembly, disassembly, repair and maintenance of tires are relatively professional jobs, and they are also high-risk types of work. Therefore, those engaged in tire repair must undergo professional training, and only those with certain maintenance skills can perform tire repair operations.
(2) Acceptance and storage of tires. After the tires arrive at the site, a designated person must be designated for inspection and acceptance to ensure that the quality of each new tire meets the requirements. The storage of tires is critical to ensuring the quality of the tires. If the tires are exposed to the outdoors for a long time, the rubber of the tires will age rapidly and the service life of the tires will be greatly reduced. Therefore, the tires should be stored according to the following requirements to ensure the service life of the tires: ① Store new tires in a cool, dark, dry place indoors, and cover them with waterproof tarpaulin. ②Keep away from electrical equipment. ③Do not put it in the same room or adjacent room with gasoline and other oils. ④Do not pile up and store vertically.
(3) Create tire card.
Each truck must establish corresponding tire files and tire cards, make detailed and accurate tire tracking records, and have detailed knowledge of the operating time or operating kilometers of each tire in use or off the vehicle.
(4) Tire assessment. In order to enhance the driver's operating level and sense of responsibility, a reasonable tire use reward and penalty system is formulated for operating drivers, and tire awards are used to promote drivers' awareness of tire protection.
(5) Strengthen road maintenance. The quality of roads directly affects the service life of tires. First of all, all indicators of the mine road must meet the prescribed standards, such as the angle of the slope, the curvature of the turns, the camber of the road surface, etc. Then there is the investment in road maintenance equipment, strengthening the sense of responsibility of the drivers of road graders and rubber-tired bulldozers, and maintaining the loading spaces (shovel nests) and dumping ground roads is particularly important.
4.2 Tire maintenance
(1) Carry out routine maintenance, air pressure testing, etc. Check the appearance of the tire every day, and remove any small stones if they are found stuck in them; avoid stones getting stuck in or causing local cuts and peeling; and maintain the standard air pressure of the tires in cold conditions.
(2) Adjustment of toe-in. Whether the front toe of the truck is normal or not is very important. If the front toe is abnormal, it will cause severe local wear of the two front wheels. The so-called abnormal toe-in means that the two front wheels are not parallel, which is what people often call the front wheel's internal and external shapes. The consequence is eccentric tire wear and premature tire scrapping. Therefore, it is necessary to frequently test the tread depth on both sides of the two front tires. If any abnormal wear is found, adjust the toe in time.
(3) Tire rotation. Use tires well to maximize the use value of each tire. After a certain period of use, the tires should be reasonably rotated so that the tread is evenly worn. In mines, especially front rotation is more important when it comes to safety. Generally, the front wheel pattern can be replaced after about 40% of the new tire is used. The height difference between the two old tires assembled on the rear wheel should not exceed 15 mm, and tires from the same manufacturer should be assembled together as much as possible.
5 Safety Precautions for Using Tires
A tire filled with gas according to the specified pressure is equivalent to a high-pressure container. If the gas is released sharply, it will explode and cause damage to equipment or equipment. causing damage to personnel. Therefore, when repairing tires, you must strictly follow the safety operating procedures for tire repairs and strictly abide by the following safety precautions.
(1) Personnel who perform tire maintenance must undergo professional pre-job training and can only start working after passing the training.
(2) When performing tire maintenance, more than 2 people must be present.
(3) Appropriate labor protection equipment must be worn when performing tire repairs.
(4) Tire repair operations should be carried out within a designated safe work area. The site should be flat, clean and stable, away from elevated lines and vehicles and pedestrians.
(5) Vehicles carrying out tire repairs must be completely unloaded, the driver must be notified to brake, turn off the engine, and the work begins after the vehicle is plated and covered.
(6) When dealing with stones in twin tires, both tires must be deflated before proceeding.
(7) When replacing a cracked retaining ring or rim, even the inner tires must be double deflated.
(8) When installing a repaired tire, the tire patch is not allowed to be installed on the outside of the tire, and two repaired tires cannot be installed on one side at the same time.
(9) The two tires assembled on the rear wheel must be of the same manufacturer and model.
Safety Technical Operating Procedures for Tire Maintenance Operations
1. Strictly implement the provisions of the "Tire Management Regulations"
2. When trucks enter and exit the workshop, they must A dedicated person stands on the driver's side to direct
3. Tire engineering vehicles are only allowed to transport one giant tire of 3700R57 or above at a time. When transporting tires, it is strictly forbidden to use a forklift or other lifting equipment to touch the rim part
4. When using a tool truck to tow the air compressor, the lock must be inserted and the operating speed shall not exceed 10 kilometers per hour
5. When disassembling and assembling all vehicle tires, the vehicle should be parked on flat ground , there are no obstacles around, no high-voltage wires in the sky, shut down and turn off the brakes
6. When disassembling the tires of heavy trucks with a load of more than 85 tons, tires of bulldozers, front loaders, and other large equipment, in addition to using a jack to support Safety support piers should be installed outside the vehicle, and wooden boards should be placed on the contact surface to prevent slipping. The operation must be directed by a dedicated person
7. Disassemble and install any vehicle tire, whether it is a single wheel or a double wheel. As long as there is a fault such as heat peeling, cut peeling, local wear, damage to the rim assembly, etc., the tire must be completely deflated before disassembly and assembly work can be carried out, including disassembly of the tire due to non-tire failure, such as replacing the front suspension, electric wheel, etc. Work
8. When installing tires, the matching tires on both wheels should not be larger than 10MM
9. When using a tire service vehicle to disassemble and install tires, the hydraulic support should be put down and supported Smooth
10. It is strictly prohibited to start driving when disassembling 789 drive 3# or 6#
11. The replaced 170D 730E 685E truck tires must be transported once or must be transported to the workshop twice. Fastening
12. When assembling and disassembling the tire or disassembling the "O" ring, it is strictly forbidden to use hands instead of tools to remove the "O" ring
13. It is strictly prohibited to remove the "O" ring in the truck Assemble and disassemble the tire
14. When the tire is installed on the rim, welding on the rim is strictly prohibited
15. Cracked and deformed locking rings, flanges, and seats must be scrapped according to regulations , must not be reused, but should be kept properly to prevent damage. When assembling the tire, the locking ring and locking ring groove must be clean, and there must be no oil, rust, etc., and the locking ring and locking ring groove must be matched
16. When inflating, the air pressure must be measured frequently and specially assigned to supervise it to prevent inflation. An accident may occur if the pressure is too high
17. During the inflation process, pay close attention to the condition of the lock ring and lock ring groove. When charging to 10-20 PSI, stop inflating and check the tightening of the lock ring again. , only after confirming that it is correct can you continue to inflate. It is strictly forbidden to place various tools and objects on the tire during the inflation process
18. When removing the tire from the stone, the tire must be deflated and disassemble the tire if necessary
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19. Faulty tires that affect safety must be deflated immediately
20. It is not allowed to check the air pressure at the mining working surface
21. When checking the air pressure at other sites, You must get in touch with the driver. After the inspection, you can not notify the driver to drive until all personnel have evacuated.
22. Tires that are 50% lower than the standard air pressure and continuously inflated must be carefully inspected and disassembled. , identify the cause and then assemble and inflate
23. The tire pressure must be carefully checked, especially when the tire pressure is high, be sure to park it in a safe place for 12 hours and wait for the tire to cool down before adjusting the pressure
Causes and countermeasures of damage to giant tires in rain and snow seasons
Abstract: Giant tires are the main consumables for large-scale production and transportation tools in open-pit coal mines. In recent years, the international tire market has been a seller's market, with prices rising year by year, and the supply of goods is very scarce. Moreover, my country's giant tire production is not yet mature and can only rely on imports. Therefore, the normal production of some domestic open-pit coal mines is restricted. This article is based on the causes of damage to giant tires in Pingshuo Open-pit Coal Mine in recent years, analyzes the common causes of damage to giant tires in rain and snow seasons, and proposes relevant preventive measures. Improve the ability to prevent damage to giant tires in both rain and snow seasons. It is a practical measure to ensure safe production and reduce costs. It is of great significance to the good management, use and maintenance of giant tires in mines.
Keywords: giant tire, cut and peel, local wear, impact burst, preventive measures
0 Introduction
The tire diameter is 2.6m and the width is 0.8m Above or with specifications above 27.00R49, they can be called giant tires. Pingshuo Open-pit Coal Mine is one of the giants in the domestic coal industry. Various advanced heavy-duty mining transportation equipment account for a large proportion. It has more than 200 heavy-duty transport trucks of world-famous brands such as CAT and KOMATSU. Its characteristics are: high work efficiency, but relatively high maintenance costs. The most expensive material spare parts of these transport trucks are giant tires. Currently, the giant tire models used in Pingshuo Mining Area include 4 specifications: 27.00R49, 36.00R51, 37.00R57, and 53/80R63. Among them, the price of 53/80R63 tires for KOMATSU930E trucks is as high as nearly 300,000 yuan. According to statistics: Pingshuo mining area consumes more than 1,000 giant tires every year, worth nearly 100 million yuan, which is a huge expense. The price of giant tires has been rising year by year in the international tire market in recent years, and supply is in short supply.
Therefore, the reasonable use of giant tires directly affects whether the truck can operate normally, and is related to mining costs and raw material consumption. As the main consumables in open-pit coal mines, giant tires have attracted increasing attention for their safety performance and cost reduction. Only the correct use and perfect management of tires can ensure the normal operation of trucks. Only by reducing the loss of giant tires can production costs be saved, and it also plays an important role in production safety.
The rainy and snowy season is the most serious season for tire damage. According to the scrapping records of giant tires in the Pingshuo Mining Area in recent years, it is not difficult to find that the number of scrapped giant tires is particularly prominent in these two seasons, accounting for more than 65% of the total scrapping of giant tires throughout the year. The above data fully illustrates that both rain and snow Mid-season tire management is very important. Strengthening the management of giant tires in two seasons can minimize tire damage and lay a solid foundation for saving tire costs throughout the year.
1 Analysis of the causes of damage
During the rainy and snowy season, heavy trucks driving on slippery, muddy and icy roads will bring certain hidden dangers to production safety, and will also cause damage to giant tires. The service life will also be affected. Here are some common damages caused to giant tires when trucks drive in rain and snow.
1.1 Cut and Peeling
Cut and Peeling means that the giant tire was not disassembled and repaired in time after being cut during operation, but continued to run for a period of time, causing partial damage to the tire tread. Peeling off, voiding, falling off and other phenomena. According to statistics, the giant tires scrapped due to cuts and peeling during the rainy and snowy seasons in the Pingshuo mining area account for more than 30% of the total scrapped amount throughout the year. At present, the heavy-duty truck tires used in the Pingshuo Mining Area are all steel radial tires, and the main transportation roads are all uneven gravel roads. Due to the exposed sharp stones in some road sections or sharp roadside stones, in rainy and snowy weather, , its transportation trunk roads are prone to water, snow, and ice accumulation, which accelerates the ability of stones and water to cut tires. If the weather conditions are bad and the driver does not know enough about the road conditions, it is easy to cut the tires when the truck runs over them. If it is not discovered in time, the uneven stress on the tires of the truck while driving will cause the wound to spread. Due to the strong penetration of air and water, under the erosion of rain or snow, it will gradually penetrate into the steel wire layer along with the tire wound, causing the steel wire to The tread layer is quickly oxidized, rusted, broken, and gradually separated from the tread rubber, causing the wound to continue to grow and deepen. If it is not repaired in time, it will cause the tire to partially peel off, fall off pieces, and even be scrapped, which is a specific manifestation of early tire damage. It would be a big mistake to continue using the tire when it is not leaking. The tire wound will no longer be able to withstand external impacts due to surface peeling and emptying. Abnormal cuts or collisions will cause the tire to burst, which will bring serious consequences to production safety. A big hidden danger.
1.2 Local wear
Local wear is commonly known as local wear. It is the tread wear caused by the uneven wear energy due to the tire pattern ridges. The specific manifestation is that the tread is partially flattened. Exposed steel wires, etc. According to statistics, the giant tires scrapped due to local grinding in the Pingshuo mining area every year account for more than 30% of the total scrapped amount throughout the year. This kind of wear directly destroys the tire structure and is fatal to the tire life. If such wear and tear occurs, the tire cannot be repaired or refurbished, and can only be scrapped. The phenomenon of partial tire wear is most prominent in the rainy and snowy season, mainly because the road surface is slippery in rainy and snowy days, and occasionally there is ice. The truck's tires will slip when starting, braking, and going up and down hills. It directly causes the tire to shift and deviate, and it also causes serious damage to the tire's wear resistance and carcass strength. According to the actual situation in the Pingshuo mining area, some drivers increase the speed very high when starting, which causes the forward thrust of the tires to be greater than the adhesion, and the tires will slip on the spot; when the truck goes uphill under load, the rear wheels will overshoot. When the load is applied, the truck will slip laterally and longitudinally with the tires. This phenomenon is often called "the car falls off its butt" by the driver. When the truck is braking, it is best to use the spot braking method. If a truck brakes urgently, the temperature of the friction between the tire and the ground will rise sharply, directly destroying the performance of the tire. Long-term braking will cause a certain piece of tire tread rubber to wear flatter and flatter until the steel wire layer is exposed, and finally the tire will be damaged. The tire tread loses its circular rolling effect on the ground. This phenomenon fully indicates that the tire has been partially worn. In addition, the inertial force of the truck moving forward will be consumed by the rubbing shear stress in the carcass, seriously damaging the carcass structure and strength, causing tread grooves to vary in depth. In order to ensure safe production, tires damaged due to local wear must be scrapped resolutely and must not be used improvised.
1.3 Impact burst
When a tire hits an object under load, it will cause rapid deformation and produce a very large stress concentration in the carcass. Then the tire may be damaged. If this kind of collision happens to happen when the truck is overloaded or speeding, when the tire hits a sharp stone or obstacle, the stress and deformation it endures are too large, which often causes the tire to burst. According to statistics, the giant tires scrapped due to impact bursting during the rainy and snowy seasons in the Pingshuo mining area account for more than 5% of the total scrapped amount throughout the year. Although the proportion is small, this kind of damage brings great hidden dangers to safety production. Tire impact bursting will also occur under the following conditions, such as: damage to the steel wires in the carcass, partial wear, cuts, peeling, etc.
Tire impact bursts are extremely serious damage to heavy trucks. Giant tire bursts generally occur in the rear wheels of transport trucks. When one of the tires on one side suddenly bursts, the driver should stop immediately. The moment the tire bursts, a shock wave is generated. It will seriously harm the people or equipment around you as well as the surrounding environment. Wait until all conditions are clear before getting out of the car and checking. If it is a heavy load, the cargo should be cleared immediately and returned to the maintenance workshop for inspection and processing; if it occurs on the two front wheels of the truck, when one of the tires bursts, it may cause the heavy truck to roll over, the frame to twist, and the suspension and If the horn shaft is seriously damaged, the direct loss is immeasurable and brings great hidden dangers to production safety.
The above three causes of tire damage are the most common in rain and snow seasons. Tire damage directly affects the service life, and is also related to production safety and cost consumption. Only when tires are used scientifically, safely and correctly can they maximize their economic benefits.
2 Preventive measures
2.1 Level the main road and purify the road surface
In the Pingshuo mining area, some loading yards and dumping yards have long transportation distances. High temperature weather can directly lead to thermal peeling of tires; the road surface of transportation trunks is uneven and sharp stones can be seen everywhere, and trucks may slip off from time to time. If it rains or snows, it is easy to accumulate water, snow, and ice, and they are not cleaned up in time. It will cause the tire to be cut or even burst due to impact. These problems directly affect the normal use of tires. As the saying goes: "It is better to repair roads than to repair cars." It is recommended that relevant departments reasonably adjust the transportation distance between the loading site and the dumping site, reduce curves, lower the slope, and comprehensively carry out quality standardization of mine engineering, especially for transportation trunk roads. For work, first of all, there should be sufficient width. On a flat basis, the center of the main transport road should be used as the base point and extend to both sides with a slope of 3% to prevent water accumulation on the road from freezing. Drainage ditches should be dug on both sides of the road to drain rain and snow. The phenomenon of tire damage caused by water accumulation on the road has been completely solved. We also implemented a contract responsibility system for transportation trunk roads and strengthened on-site road leveling and maintenance work with road graders and bulldozers.
2.2 Strengthen measures to ensure smooth traffic
In rainy and snowy weather, undesirable phenomena such as truck slipping and tire spinning will occur when trucks go up, downhill or turning, especially It is most prominent on the working surface where loess is transported. These problems can cause serious damage to your truck and tires. It is recommended that when it rains or snows, make full use of the scraper to spread gravel on the main transportation roads, slopes, and curves to increase the friction between the tires and the ground, minimize the occurrence of truck slippage, and make the transportation truck stable. , safe and smooth operation.
2.3 Strengthen training and improve quality
At the mining site of open-pit coal mines, shovel drivers, truck drivers, bulldozer drivers, road grader drivers, etc. all have relevant knowledge about tires. connect. Problems in every link will cause abnormal tire consumption. For example, when a shovel driver loads a truck, abnormal wear of the tires will be accelerated if the truck is overloaded or unbalanced. Therefore, the loading quality of the shovel is critical to the tires. It is particularly important; the truck driver is the first person responsible for tire use. He should be primarily responsible for tire cuts, wear, and bursts caused by the truck during operation. This requires the truck driver to check the condition of all tires before and after the shift. If there is any problem, Repairs should be reported promptly and detailed records should be kept. When driving, be sure to start at a low speed, move forward at a constant speed, brake at a certain point, and try to avoid rolling over stones or other obstacles; the bulldozer driver should also take care of the work surface cleaning of the dump site and loading site, and should avoid trucks entering the work as much as possible The phenomenon of stones and other debris being crushed behind the surface; the road grader driver has the closest relationship with the tires, and the quality of his work directly affects the service life of the tires. First of all, work methods such as "quantitative road construction and regular inspections" should be followed, and problems should be dealt with in a timely manner. Only by cooperating and caring for the above four types of work can the tires be used safely and rationally at the mining site, so that the equipment driver can develop a sense of responsibility of "loving tires and saving tires". The above-mentioned employees should be trained regularly to improve their professional quality, strengthen their sense of responsibility, and contribute to ensuring the normal use of giant tires.
2.4 Regular maintenance and filing for reference
Planned maintenance work is currently the most advocated work idea in the maintenance industry, and it is also feasible for tires. Tire planned maintenance work is divided into two parts: First, strengthening daily tire inspection is a preventive measure to ensure the normal operation of tires. Truck tire pressure, wear degree, etc. must be carefully checked through daily maintenance, equipment refueling, etc. , and make detailed records and feedback to the workshop. It is necessary to know every truck and every tire thoroughly, and make planned replacements for tires that need to be replaced; secondly, comprehensively carry out preventive tire repair work, which means that tires should be repaired promptly after they are found to be cut. If a tire cut is not discovered in time, the wound will become larger and larger as the use time increases, and the value of repair will be lost when it peels off or falls off. This work requires the full cooperation of equipment drivers, tire workers, and maintenance workers. Strengthen the inspection of tires during daily inspection, oil filling and inflation, so as to extend the service life of tires. If necessary, some reward and punishment measures can be taken to improve the enthusiasm of staff.
2.5 Strict assessment, clear rewards and penalties
The quality of tire-related work directly affects the service life of the tire. Implementing an economic responsibility system for tire workers is the fundamental guarantee for managing tires well and reducing costs.
Comprehensively establish a safety and quality standardization work system for tire assembly, disassembly, replacement, repair, and inflation, and formulate relevant job responsibility systems to encourage every tire worker to complete their work safely and under standards. Regularly organize relevant management personnel to conduct assessments on tire work safety and quality. Teams and individuals who have safety or quality problems during the assessment must be given clear rewards and punishments in order to fully mobilize the enthusiasm of on-site tire staff.
3 Conclusion
By analyzing the most common causes of damage to giant tires in rain and snow seasons, and implementing the above practical preventive measures. In 2008, Pingshuo Mining Area received good results. First, the service life was extended, with an average service life of nearly 700 hours compared with last year. Second, the number of scrapped tires was reduced by 45 compared with the same period last year, equivalent to more than 5 million yuan, accounting for approximately 10% of the annual tire cost; the third is to ensure safe production and lay a good foundation for tire-related work in the coming year.