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Views on the current situation and development of domestic rotary drilling rigs

Abstract: This paper introduces the domestic overview, market demand and shortcomings of rotary drilling rigs with detailed data, and puts forward its own views on the development of domestic rotary drilling rigs

key words: development gap of rotary drilling rigs

1 Analysis of market demand for rotary drilling rigs

at present, China's ongoing large-scale urbanization construction provides a broad market demand for rotary drilling rigs. According to the statistics of the National Bureau of statistics, there are currently more than 660 cities in China, including more than 170 large cities with a population of more than 1 million. With the development of the national economy, the urbanization process will also accelerate. New pile foundation projects in the reconstruction of old cities and the construction of new cities will increase significantly. According to the urban construction and national long-term planning, huge investment is invested in the development of projects. The engineering projects to be invested in the short term are hundreds of billions of yuan. The market demand for rotary drilling rigs is calculated and analyzed from the number of units occupied by each city. The total number of rotary drilling rigs in China will reach 2000 in recent years. Due to its multi-function, high efficiency and other advantages, rotary drilling machine has already become the main type of cast-in-place pile construction machinery in foreign developed countries

in, the annual demand of domestic rotary drilling rigs is estimated in the following table:

year 2005 2006 2007 2008 2009

the estimated annual demand is 200 220 200 150 140 130

in short, the development of rotary drilling rigs has a good prospect in China, and a large number of imported products are pouring into the Chinese market, while the development of similar products in China is still in the initial stage, and will be in the rising period of rapid development in the next few years. Today, at the beginning of the century, China is in a period of great development. All kinds of engineering construction urgently need a large number of construction machinery, especially highway and bridge, railway, water conservancy, urban development, which requires a large number of pile machinery and equipment. From the speed of its development, the huge market outline of rotary drilling rig has appeared

2 the gap between domestic rotary drilling rigs and foreign products

2.1 domestic overview

rotary drilling rigs have been gradually popularized and applied in China in recent years, and a large number of imported products are pouring into the Chinese market, while the number and variety of similar products in China are small, and the development and production is still in the initial stage. From the perspective of the speed of development, the market of rotary drilling rigs is huge. However, the main factor restricting the import of rotary drilling rigs is their high price, which is also the reason for the booming market of second-hand rotary drilling rigs in some regions. Rotary drilling rig is an electromechanical equipment with high technical content and strict requirements for use technology and equipment maintenance. In recent years, several domestic units have successively carried out some development work on rotary drilling rigs, but due to various reasons, they have not been able to form a series of mature products. In the early 1980s, China introduced the working device from Japan and installed it on kh-125 crawler crane. In 1984, Tianjin exploration machinery factory introduced the rotary drilling rig of American RDI company and digested it. In 1987, the products of Italian Soilmec were exhibited for the first time in Beijing exhibition hall. In 1988, Beijing urban construction machinery factory developed a 1.5m diameter crawler crane attached rotary drilling rig based on the prototype of Soilmec. In 1994, Zhengzhou survey machinery factory introduced the production technology of British BSP attached rotary drilling machine, but there was no mass production. In 1992, baoe company set up a representative office in Beijing, China, and began its business in China. In 1995, baoe Tianjin Mechanical Engineering Co., Ltd., a wholly-owned subsidiary, was established in Tianjin to assemble baoe bg20 rotary drilling rig suitable for the Chinese market. In 1998, a Sino German joint venture Shanghai baoe Jintai Construction Machinery Co., Ltd. was established in Shanghai to produce and assemble BG15 rotary drilling rig. In recent years, rotary drilling rigs in China have achieved rapid development. At present, there are more than ten domestic manufacturers of rotary drilling rigs, mainly including XCMG technology, Sany Heavy Industry, Beijing Jingwei Juli, Hebei Shijiazhuang Coal machinery, Hunan Shanhe intelligent, Hangzhou Tianrui, North heavy truck, Harbin Sihai, Zhengzhou Jinniu, Lianyungang Huanghai, Lanzhou General Motors, Xinhe drilling rigs, etc

at present, foreign rotary drilling rig companies mainly invest in domestic companies: German baoe company, whose product series are bg12~bg25; Italian soil company, whose products are r412~r618; Hr130~hr240 of MAIT company; Af6~af50 of IMT company; Th12~th25 of CMV, etc. The maximum torque of foreign products can reach 36. The other one is 0knm in the beam, the engine power is 448kw, the drilling diameter is 4 meters, and the drilling depth is more than 90 meters. The brands are mainly concentrated in earth power, baoe, Yima, Maite, Casa Grande, Juli, and small torque rotary drilling rigs made in Japan

2.2 main gap

2.2.1 technical status of domestic rotary drilling rig

(1) the overall hydraulic system and configuration of domestic rotary drilling rig cannot reach the advanced level of foreign countries, especially compared with the world's advanced baoe drilling rig, there is still a certain gap. Foreign hydraulic systems adopt constant power systems or load sensing systems, and hydraulic components adopt internationally advanced and mature products

(2) the key components of domestic rotary drilling rigs, such as drill pipes, especially machine lock pressurized drill pipes, cannot meet the requirements of the host machine. The main reasons are: first, the roundness and straightness of domestic steel pipes cannot meet the design requirements when processing steel pipes, and neither the strength nor the accuracy can meet the requirements. Second, the processing technology of drill pipes is still under exploration, the welding quality cannot be guaranteed, and the deformation is easy to be adjusted after welding

(3) the appearance of the domestic rotary drilling rig and the layout of the instrument panel in the operation room are not as good as those in foreign countries. In this regard, we should learn from other domestic construction machinery, such as excavators. Some foreign rotary drilling rigs are equipped with full computer operating systems, so that the operator can master the drilling depth and the verticality of the drill frame in real time, so as to ensure that the drilling hole accurately reaches the design depth and maintains a good verticality; Grasp the working conditions of each system in real time, so as to take maintenance measures in time and ensure the normal operation of the drilling rig

(4) there is no display function for the engagement between the drill pipe insert and the power head and the drill pipe state of the domestic rotary drilling rig

2.2.2 technical status of foreign rotary drilling rigs

(1) the drill pipe teeth of foreign rotary drilling rigs have the function of displaying the engagement with the power head and the drill pipe status. The addition of these functions is indeed very practical. Anyone who has used a rotary drilling rig knows that the drill pipe inserts are very easy to wear (especially in the case of incomplete engagement), and the repair after wear is also very troublesome. In the past, the operator can only feel the meshing situation based on his own experience, so the requirement for the operator's proficiency is very high. With the display function of drill pipe tooth engagement, the display can accurately display the tooth engagement, which can be operated well even by an inexperienced operator, and greatly reduce the labor intensity of workers. During the drilling operation, the drilling depth often reaches tens of meters. Due to geological conditions, drill pipe and drill pipe, drill pipe and drill bit connection and other reasons, the drill pipe and drill bit fall off in the hole, causing great losses to the construction unit. The display function of drill pipe status provides a visual drill pipe for the operator, which facilitates the operator and avoids accidents

(2) when the rotary drilling rig is drilling, there is a process of drilling - lifting - rotating - throwing soil - rotating to the original orifice - aligning - re drilling. Domestic rotary drilling rigs have no return positioning function, so they also bring opportunities for the industry to borrow ships to go to sea, which consumes a lot of time and energy on time, and the manual alignment accuracy is low. The drilling rigs of Germany baoe and Italy CMV have the function of return positioning. The so-called return positioning function refers to that the machine can record the rotation angle when it rotates. When it returns after dumping, it will automatically stop once it reaches the recorded angle. In this way, ensure that it returns to the position before the first rotation. The labor intensity is greatly reduced, and the production efficiency and operation accuracy are improved

(3) foreign rotary drilling rigs have concrete cast-in-place pile mode. This mode can display concrete pressure, concrete flow, hydraulic system pressure and concrete pile shape to ensure the quality of piles

(4) foreign rotary drilling rigs are multifunctional. It can select a variety of drilling tools to operate in different soil or rock layers, and can carry out drilling, continuous wall grooving, precast pile construction, rock drilling anchor rod and other operations by replacing drilling tools. That is, the drilling rig adopts a multi-purpose modular design

can be used for:

- large diameter short screw and rotary bucket rotary construction

－ long spiral construction

- follow the pipe construction of the whole casing

- Construction of full casing followed by pipe + pile grinder

- Construction of underground diaphragm wall with hydraulic grab

－ high pressure rotary spraying construction

- DTH hammer construction

- precast pile construction

for the construction of the above different construction methods, only different work accessories need to be installed, so that one machine can be used for multiple purposes and the use cost can be saved. At present, bmuer company, Soilmec company, Casagrande company, etc. have all kinds of construction machinery

(5) foreign rotary drilling rigs adopt electro-hydraulic proportional servo control system, PLC, can bus control, etc., which improves the positioning drilling accuracy, and has the automatic detection of drilling depth, fluorescent screen display function, etc. when the drilling rig tilts, the drilling rig will automatically alarm and automatically adjust. The multi-functional liquid crystal display that can display a variety of information can be used to control the drilling rig, automatic vertical leveling, rotary dumping control, the monitoring of the engine taking another sample for rework, the measurement and display of the drilling depth, the animated display of the working state of the car body, the display of virtual instruments, fault detection and alarm and other information

(6) foreign rotary drilling rigs are well protected. The safety of the operator is fully considered in the design of the drilling rig, and some measures are taken:

- the front window of the cab is equipped with FOPS (falling object protection)

- height limit of winch

－ safety control of console in cab

－ engine, hydraulic and other parameters display, alarm, etc

(7) foreign rotary drilling rigs generally cooperate with professional manufacturers or develop their own special controllers and control software in terms of control functions. However, the domestic rotary drilling rig basically adopts imported control functions and does not have its own software

in short, at present, there is a big gap between China's rotary drilling rigs and foreign rotary drilling rigs, both in function and technology. Although the product cost is relatively low, it is incompatible with social development. In order to occupy a place in the increasingly fierce market competition of rotary drilling rigs, we must constantly improve the old products and gradually develop new products with high starting point and high-tech content. The energy used accounts for about 12% of the total energy consumption of the national economy

2.3 development direction of domestic rotary drilling rigs

(1) based on China's national conditions, develop large, medium and small rotary drilling rigs of different grades. Especially small and medium-sized rotary drilling rigs. Due to fierce domestic competition, try to reduce costs and improve reliability

(2) committed to the research on the construction method of rotary drilling rig. Develop new products in combination with construction methods, realize product serialization, meet various needs of customers through product personalization and differentiation, and vigorously develop the varieties of rotary drilling rigs. On the one hand, we should be good at learning from foreign rotary drilling rig enterprises and drawing on foreign advanced technology of rotary drilling rigs, and design and produce products suitable for China's national conditions on the basis of reference