Analysis and Application of Hydraulic System of Hydraulic Pile Driver

Analysis and Application of Hydraulic Pile Driver Power System Cai Zheng Xie Xushi Guo Jinji Chen Hai 31. Guangdong Dianbaidi Construction Engineering Company, Guangdong Dianbai 525200; 2. Guangdong Guangyuan Engineering Company, Guangzhou, Guangdong 51; 3. Zhongshan University, Guangzhou, Guangdong Dynamic response of the 510275 force system. Give the application afterwards. Application examples of the project.

The velocity acceleration of the force piston motion, analyze the dynamic response of the power system, and explain the related problems of construction engineering application.

1Hydraulic control system The hydraulic pile driver adopts full hydraulic walking type walking device, the working platform travels up and down, that is, the Descartes coordinate 2 direction movement, and the construction is called the horizontal ship longitudinal ship and the extension leg and the pile pile pile. All the movements are The hydraulic control system and its servo mechanism are completed. At present, there are 30074007500 series pile machines, which can be used for side pile construction.

The hydraulic pile machine crossbar is displaced by two cylinders in a short distance. The longitudinal tank is connected by two oil cylinders in parallel to complete the other direction of the longer distance, and the exact positioning of the pile is coordinated. The legs are vertically displaced by a cylinder distributed at the corners of the platform. There is a cylinder on the pile-picker, which is divided into two groups; the pile can be held at the same time, so that the pile-holding force is divided into two parts, which reduces the excessive concentration of pressure and prevents the broken pile from happening. The pile-pile cylinder can be divided into two groups of the main pressure cylinder secondary pressure cylinder. According to the model of the pile driver, the cylinder bore diameter is also different. The pressure setting labeling machine is also called the hydraulic pile driver. It is a new type of building foundation construction machinery, with no Strong shock and vibration, no noise, single pile bearing capacity, high test pile and fast construction speed, etc., have been widely used in large and medium cities, differential equations, using Laplace3 to derive the transfer function, and using 1 but 8.6; inverse transformation to solve the equation, obtain The oil pressure is ideal for the clamping force. The user can adjust it according to his own needs. The oil circuit has been set with secondary pressure and follow-up relief valve control.

Hydraulic pile machine crossbar longitudinal ship extension leg pile pile and pile pile sleeve hydraulic control system, except hydraulic oil pump relief valve check valve flow control check valve position valve relief valve type cylinder cylinder diameter length is different, hydraulic principle and control The system lines are identical.

See 1. The following selection of the position valve and cylinder composition for power system analysis.

2 transfer function of hydraulic servo. The position of the valve is composed of a piston and a cylinder. 2. The spool action of the position valve is generally simplified as follows. When the control signal solenoid valve is given, the high pressure oil is connected to the cylinder 1 when the spool is moved to the right; The power piston moves to the right and drags the load M to operate; the cylinder chamber is low pressure oil flowing back to the storage cylinder through the right channel of the spool. When the control signal solenoid valve is given and the spool moves to the left, the high pressure oil and oil return direction are opposite to the above, the piston will move to the left direction, and the power cylinder is unloaded and reset.

The drag load referred to here refers to the force including the mass displacement of the vertical ship longitudinal platform of the lifting platform of the pile-supporting pile. Assume that the amount of oil entering the power cylinder is the pressure difference between the two sides of the power piston. The displacement of the valve spool is long-term 2, then it can be regarded as the function of the household and the household. It is a nonlinear relationship.

Put the nonlinear equation 1 at the rated working point, the brother, the ruler, according to the lower 1 of the element, and linearize it. If the rated working conditions of the system are selected, =, ==, then =, then from 3 generations 2 can be obtained by 2, the incompressible oil flows out, the product of time ratio is equal to the product of the displacement area of ​​the power piston and the density of the oil, ie, =, the generation 4 thrust assumes the power piston The dragged load, mass, and viscous friction coefficient, the force generated by the power piston will be used to overcome the inertial force and the frictional frictional resistance. At this time, the differential equation of motion of the servo system dynamic system is quantified 8, 2, for example, the viscous friction coefficient, and the positive direction of 8.7.

Using the initial condition 00 = 0, the transfer function of the hydraulic servo mechanism can be determined by the equation 6 as the order, and the equivalent is the time constant. If the time constant is negligible, the transfer function 8 is transmitted. Block 3, implements open loop program control.

3 The dynamic response of the cylinder power system is set. The solenoid valve is controlled by the solenoid valve. It is an inductive load. The displacement can be changed by the response time of the small movement of the following type; 0 is the maximum distance of the movement of the spool.

The equation 1 is transformed by the Laplace transform and the inverse equation of the Laplace transform, and then the inverse differential equation of the dynamic piston can be solved by the inverse Laplace transform. The length 151 is obtained from the above analysis. Out, in addition to the area of ​​the piston, 4, it is also related to the two sides of the living cold; the jade force is related to the corpse, that is, the distance from the electromagnetic sliding movement. Under the condition that the oil density is 3 and the plant system is stable, the law of the 5th type can show the change of the drag load of the power piston with time. Generally, the time constant of the inductive load of the electromagnetic valve and the time constant T of the driving device are selected small. When r3 is 3r, the speed of the power piston dragging the load can be determined by the differential of the 3rd type and the time, and the selection is small, and When it is 3 to 3, the speed tends to be constant, so that the power system works stably. According to the 14th type, the speed can be delineated by the differential method, which can be differentiated by the 14th type. After finishing, the 16-type calculation can be used to calculate the power piston drag load. 4 Construction Engineering Application The full hydraulic static pile driver is a newly developed building foundation. Construction machinery products. Taking the 21500 butyl pile-pressing pile as an example, it can be said that the calculation from the oil-circuit system can not be obvious only when the pressure of the oil pump is suddenly stopped from the static pressure pile. For example, opening degree, = large, not enough, pressure can not go, can not reach the rated value.

The oil supply system of the cylinder directly affects the working state of the power piston. It can be seen from the 3 formula that 1 is 2 = 么, =., 2 is called the flow channel main channel flow increment and flow pressure coefficient respectively. The latter is determined by the slope of the flow pressure characteristic curve at the selected operating point. Under steady working conditions, the diameter of the known cylinder is 4280, and the pile speed is 0=4.931! It can calculate the single-cylinder oil supply flow, which is less than 0.30363. For example, there are 4 main and auxiliary cylinders. Therefore, the oil supply flow rate of the power piston supply system should not be less than the time constant 1 of the main control solenoid valve of the position-passing valve and the time of the power system. The constant 7 should be chosen to be a child, so that the system can work stably. Since the solenoid valve is an inductive load, the time constant is usually chosen to be no more than 50. The time constant of the power system is not more than 8, when 3, 3, the mountain 15 type can obtain the power piston. =, converted pressure, speed is 4.93, 10.082 claws, the acceleration is zero.

According to the type 17 can check the pressure of the oil pump, the piston thrust is known to be 500. The main cylinder has a total of 4 cylinder pistons to withstand 1257 diameter 28,1 which can be calculated as oil pressure can not be small dry 20.3 now select 23MPa to ensure normal operation.

Explain how to make the power system work stably. The maximum pressure pile force of the 21 5001 pile driver is 500 â–¡, which is provided by the main and auxiliary cylinders. The system oil pressure is 23, the piston diameter is 28, and the power pile piston is connected to the load. After the pile is pressed, the power piston thrust factory passes. The pile-holding pile is applied outside the foundation, and must overcome the frictional resistance between the foundation of the pile 4 and the inertial load caused by the instantaneous acceleration of the movement or sudden stop. 2. The known pile diameter is 500, the length B = 15, and the density is 7 piles. The mass is approximately equal to 13. The instantaneous starting acceleration = 4.9 yang, 2, the pile and ground friction coefficient = 0.25, from which the factory 2 = 7791 power piston thrust must be greater than + heart multiplied by the safety factor. 7 is related to the sudden loading of the power piston and the characteristic coefficient of the cylinder power system. If it is selected as 2, the hydraulic static pile driver equipment has the following advantages in the foundation engineering construction. 1 Civilized construction site is clean, noiseless and pollution-free environment, surrounding Buildings are not damaged by shock and vibration.

2 Due to the use of hydraulic and loaded piles, the vertical load of each pile can be guaranteed, and the uneven settlement deformation of the pile foundation after loading is reduced; and the bearing capacity of the single pile is high, and the pile body quality is easy to guarantee. 3 The construction speed is fast, the applicability is strong, and the visibility is high. 4 The test pile speed is fast, and the best pile driving speed, the final pile load control amount and the settlement amount can be known early in the test pile before the pile pile, and the parameters of the original pile are guided by this parameter. 5 It can be carried out by using pile load and equipment and pile static load test instrument; timely testing of pile mass bearing capacity and deformation to ensure pile foundation quality.

The equipment also has certain shortcomings, such as equipment assembly is large, the construction site has a large working surface and the equipment has a large self-weight, and it needs a good traffic environment and lifting facilities. Despite this, hydrostatic pile equipment has been widely used in large and medium cities due to its unique advantages.

The motion differential equation of the hydraulic servo mechanism is established, the velocity acceleration of the dynamic piston motion is obtained by Laplace transform, the dynamic response analysis and the steady-state working conditions are obtained, and the power system is provided with sufficient carrying capacity, safe, reliable and stable. Land work has greater guiding significance.

Memtt, HE. Hydraulic control system M. Chen Yanqing and other translations. Beijing Science Press, 1978.

Guo Jinji, Feng Daocun, Xie Yingying I Hydraulic control system for the unloader gate. Celebrating the 60th Anniversary of the University of Zhongshan University, the collection of mechanics 0, 1984.

Guo Jinji and other steel pipe plastic forming hydraulic filling system is the author of the introduction of Cai Zheng, male, assistant. Research field construction machinery design and application 1.

The 1st International Conference on Mechanical Engineering and the 6th International Federation of Mechanical Engineering Associations will be held in Shanghai. The International Federation of Mechanical Engineering Societies is an international organization of 55 mechanical engineering academic groups from 49 countries and regions. In order to actively promote the development of mechanical engineering technology in the new century, the 6th International Federation of Mechanical Engineering Associations will be held in the month of 2000; 20th to 22nd at the Shanghai International Convention Center in China, and the 1st International Conference on Mechanical Engineering will be held simultaneously. . In order to meet the new challenges of the 21st century, the 1st International Conference on Mechanical Engineering will focus on the globalization of manufacturing. In addition to the theme report of the conference, ten special papers will be set up and a corporate forum on strategies and measures to enhance competitiveness will be established. j Conference will invite Chen Qingtai Executive Deputy Director of the State Council Development Research Center Lu Yongxiang, Dean of the Chinese Academy of Sciences, Xu Guanhua, Vice Minister of Science and Technology Tian Changlin, President of the United States, John Paco, President of the American Society of Mechanical Engineers, Li Rongbin, Director of the Department of Mechanical Engineering, Hong Kong Polytechnic University, Smith 8 For example, the vice president of Germany Audi company and other famous people at home and abroad, said on the theme of the conference.

At the same time, 15 famous entrepreneurs and industry management experts will be invited to give speeches and discuss with the participants. The combination of high-level large-scale technology and economy is the hallmark of this conference. This is an excellent opportunity for academic exchanges to obtain products and technical information, as well as to find partners. We warmly invite the entrepreneurs of Guangdong Machinery Industry to participate in the meeting.

Contact Information Academic Office of the Headquarters of the China Mechanical Engineering Society.

Address: Chen Baoxia, No. 46, Lihe Road, Xicheng District, Beijing

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