The milling machine is also important in the usual selection. Depending on the project and the engineering material, the milling machine can be selected roughly. For large construction projects, a milling machine with a milling width of 2m or more and a high degree of automation should be used. In this way, it is used in conjunction with maintenance machinery and equipment, which can better reflect the advantages of modern operations and save a lot of manpower and material resources. For general maintenance and municipal engineering, a small milling machine with a milling width of 0.5 to 1.3m should be used, which not only makes the operation simple and convenient, but also fully meets the construction requirements.
1. The performance requirements of the milling machine
The selected milling machine should also make clear requirements in the following aspects, and some projects must have certain quantitative indicators.
(1) Power performance. The engine of the milling machine should have sufficient overload capacity (power and torque) to ensure that it can rely on its own power to complete the milling work and the necessary site transfer under full load to adapt to the increase in smoke resistance encountered Unstableness caused by the big.
(2) Work reliability. The working reliability of the milling machine depends on the technical strength of the manufacturer and the manufacturing quality of the supporting parts, and the maintainability of the milling machine itself. Equipment with high working reliability has the characteristics of low early failure rate, fast failure repair speed and long interval between overhaul of the machine.
(3) Environmental adaptability. The climate adaptation conditions of the milling machine should be selected according to the needs of the project. For example, high temperature areas should prevent engine deflagration, low temperature areas should make the engine easy to start, humid weather areas should prevent components from corrosion, and climate areas should be protected from cooling water Evaporation is fast, and areas with low oxygen levels in the plateau should prevent problems such as a drop in engine power.
(4) Safety and comfort. The milling machine must have a good view and operating space. The driver should be able to observe the outer edge of the milling plan and the working condition of the conveyor belt from both front and rear directions. Anti-rollover safety protection devices can also be added to place strict requirements on the vibration damping, sound insulation, dust removal, steering, braking and flexible operation of the milling machine.
(5) Man-machine exchange function. The fewer the operating parts of the milling machine, the better, the simpler the better. It is necessary to install necessary indicating instruments, and an automatic alarm system should be provided for certain faults, and it is even necessary to add an intelligent control system to realize automatic control.
(6) Appearance requirements. Provisions are made on the appearance, color, sealing, packaging and transportation of the milling machine.
(7) Environmental protection requirements. The milling machine should not have leakage problems such as oil, water and electricity. The noise and smoke emission of the machine should be within the specified range.
2. Components assembly of milling machine
The configuration of the whole machine should meet the construction conditions and the appropriate economic affordability. The necessary items should be indicated in the purchase contract.
(1) Engine. Choose whether the engine cooling method is water-cooled or air-cooled, the product brand or manufacturer, and the emission standards comply with TIER1 or TIER2 to meet the construction environment. The air filter should be easy to clean and replace. The installation of the intake and exhaust pipes must not obstruct the driver's sight. The engine hood can be easily opened for maintenance.
(2) Working device. Determine the form of the drive system is full hydraulic, mechanical or crawler, wheel type; milling wheel diameter and milling depth, indicating whether the working direction of the milling wheel is up milling or down milling. The tool holder system should be assembled as a standard part, easy to replace at any time, the cutter head can be quickly replaced, and a sprinkler device and a conveying device for recycled materials that meet the needs of the construction project must also be prepared.
(3) Transmission system. Clearly indicate whether to use mechanical transmission, hydraulic transmission, or hydraulic + mechanical transmission, so that the machine can have a good passability. In addition, the machine must have two speeds of driving and working to adapt to various operating environments. Quickly transfer work sites, etc.
(4) Braking system. Brakes with sufficient capacity must be provided to determine the service braking mode and emergency braking control mode. It can also be matched with an automatic protection system, which can automatically brake when the pressure of the hydraulic system decreases.
(5) Hydraulic system. The milling machine should have its own independent walking and steering hydraulic system, with good hydraulic oil filtering and cooling performance.
(6) Control system. The milling machine should have a simple and convenient operation control system, even a highly automated control system should be easy to operate, to avoid increasing costs and maintenance costs.
(7) Electrical system. The milling machine should be equipped with reliable electrical components and connectors. It has functions such as fault diagnosis, fault alarm and repair and maintenance prompts, which can intuitively read various data and obtain the status parameters of various equipment under the working state of the milling machine.
3. Milling thickness and degree of mechanization
The construction of road maintenance and road rollers usually depends on the thickness of asphalt mixture and cement layer to a large extent. The load-bearing capacity, surface wear resistance and surface compactness of high-grade highways have strict requirements. Its maintenance layer thickness is generally about 200-300mm. A milling machine with a milling depth of 200mm or more should be used Consider its milling width; for general small projects, you can choose a small milling machine with a milling depth of about 150mm, and use a relatively simple and easy to operate milling machine.
4. Climatic conditions of the construction site
Winter construction should reduce the driving speed of the milling machine. Due to the low temperature in winter, the asphalt mixture layer becomes abnormally hard, which increases the load of the milling drum. Therefore, a larger milling machine should be used to reduce the working speed to improve the construction quality and reduce replacement. The number of cutter heads prolongs the service life of the cutter head. In addition, in the cold season, the milling machine with air-cooled engine should be selected, and the fuel, hydraulic oil and lubricating oil suitable for low temperature should be used to enhance the starting performance of the engine and prevent freezing. The milling machine constructed in the plateau area should also use an air-cooled engine with a turbocharger.
5. The need for technological progress
Foresighted engineering contractors will pay attention to keeping their construction equipment necessary technical reserves to show their company's technological leadership. When users buy a milling machine, they must consider the need for product replacement and bidding in the construction of modern projects.
6. Maintainability
Users should buy standard equipment and series of equipment as much as possible. The advantage of this is that it is easy to familiarize with the equipment, facilitate maintenance service and spare parts storage, and can significantly reduce the cost of milling machine. The engine, mechanical transmission system, milling principle, working system, hydraulic components, control mechanism and tires of the series milling machine have a high degree of generalization, which can greatly reduce the spare parts inventory, and its operation, maintenance and repair methods are also available. With great similarity, after the driver and maintenance personnel are familiar with the milling machine of one specification, they can easily master the same series of milling machines of other specifications, which greatly improves the work efficiency.
7. Technical support conditions
When a user purchases a device, in a sense, it purchases a "service". Therefore, if you purchase a certain type of milling machine, you should have a correct evaluation of the technical support conditions and quality assurance system of the milling machine itself and its manufacturer. The technical support conditions should include whether the relevant technical guidance documents, such as instruction manuals, parts catalogs, operation instructions, etc. are complete, whether they have the necessary maintenance and spare parts supply network, service network, etc. In addition, the manufacturer's technical strength and quality assurance system should also be investigated.
