Bulldozer is a kind of engineering vehicle, which is composed of torque converter, transmission and other components. It is widely used in construction projects, and can be used for site cleaning or leveling, excavation of foundation pits with small depth and backfill, and construction of subgrades with low height. This article will introduce to you some of the main classifications and technical requirements of bulldozers.
1. The main classification of bulldozers
1. Divided by walking mode:
Bulldozers can be divided into two types: crawler type and tire type. Crawler bulldozers have large attachment traction force, low ground contact pressure (0.04 to 0.13MPa), strong climbing ability, but low driving speed. The tire bulldozer has high driving speed, flexible maneuverability, short operation cycle time, and convenient transportation transfer, but the traction force is small, which is suitable for the situation where the worksite and field work need to be changed frequently.
2. According to usage:
Driven crawler bulldozer
It can be divided into two types: general type and special type. The universal type is a model that is produced according to standards and is widely used in earth and stone engineering. The special type is used in specific working conditions, including wetland bulldozers and swamp bulldozers that use triangular wide track shoes to reduce the ground contact pressure, amphibious bulldozers, underwater bulldozers, cabin bulldozers, unmanned bulldozers, high prototypes and high Bulldozers operating under wet conditions, etc.
3. According to power:
Small, medium and large (> 250kw)
4. According to walking system:
Wheel bulldozer, crawler bulldozer
5. According to the operation mode:
Steel cable bulldozer, hydraulic bulldozer
6. According to the transmission mode:
Four types of mechanical, hydraulic mechanical, full hydraulic, electric transmission, etc.
2. Technical requirements of bulldozer
1. Adopt humanized design
The appearance of the bulldozer produced in China and the layout of the cab are still far behind those of the advanced countries in the world. This has little to do with competition in the Chinese bulldozer industry. In view of China's accession to the WTO, the trade barriers to foreign equipment have gradually been lifted, and it must be aligned with advanced foreign companies. It pays great attention to the appearance of the product and the comfort of the cabin. The control system is gradually approaching the excavator and automobile industries to reduce the driver's labor intensity. The instrumentation adopts a three-level alarm electronic monitoring device and automatic fault diagnosis device. The cab uses a closed, air-conditioned cab with air filtration device, and adds advanced electronic equipment such as a tape recorder or even DVD to maximize the humanity of the driver化 Request.
2. Application of energy-saving technology
1). The hydraulic system of the working device adopts fixed-difference overflow technology. In this way, when the directional valve of the working device is in the process of throttling and speed regulation with a small opening, the excess oil supply of the oil pump can be directly returned to the oil tank from the differential pressure valve without returning to the oil tank through the safety valve, so that the system pressure is only higher than the working pressure during the speed regulation High certain value △ P, so as to achieve the purpose of reducing hydraulic power loss and oil temperature.
2). The hydraulic system and transmission system of the engine and working device adopt full power matching technology. The engine can automatically adjust the power output to the transmission system and the hydraulic system of the working device according to the actual working conditions, so as to maximize the use of the engine power to achieve the purpose of energy saving.
3). Hydrostatic transmission technology. The transmission adopts static pressure transmission. The whole machine reduces transmission components such as gearbox, torque converter (main clutch), steering clutch, etc., thereby greatly reducing mechanical power loss, and it is very easy to achieve full power matching with the engine to achieve energy-saving purposes.
3. Engine emissions meet Euro Ⅱ standard
With the increase in the construction and maintenance of transportation and infrastructure in large and medium cities, as well as the increasingly strict environmental protection requirements in the domestic and international markets, the engine emission requirements have reached at least Euro I standards, and some developed countries have even required to meet Euro II standards. Therefore, the engine equipped with the bulldozer must meet this market requirement as soon as possible.
