Through in-depth analysis of the current situation of control system of static pile driver at home and abroad, the previous control of static pile driver is expounded.
Problems existing in the system. In view of this situation, the electromechanical integration technology solution of hydraulic static pile driver is put forward. PLc, electro-hydraulic control
System technology is applied to control system. According to the actual needs of products and users, the automatic stacking, leveling and floating of the machine are designed.
Practice has proved that its alarm control and automatic recording of construction data perfect the static pile driver.
The performance is greatly improved.
Keywords: static pile driver, electromechanical integration technology PLC
1. Introduction
Hydraulic static pile driver is a kind of pile foundation construction equipment, which is mainly used in deep and soft upper layer, uneven soil and places with large vibration.
When building various buildings on the load site, it is especially suitable for the construction of high-rise buildings, heavy-duty workshops and buildings with special requirements.
Where things are built. Because the hydraulic static pile driver has many advantages such as no vibration, no impact, no noise and no pollution.
It has been widely used in construction. However, due to the manual control of the hydrostatic pile driver, its function is too simple.
Single, so there are some problems that can not be ignored in practical application: 1) manual operation, the operator's labor intensity is high, and it is easy to fatigue;
2) The vertical precision of pile pressing is poor, so it cannot be adjusted in real time; 3) The static pile driver is easy to float or even sit down, causing equipment safety accidents.
There are also some related theoretical studies on the above problems in China, but they are all systematically and comprehensively solved as a whole, and actually respond to them.
It is still rarely used now. Therefore, the main work of this paper is to develop a set of electromechanical and hydraulic integrated control system and apply it.
The test on ZYJ series static pile driver produced by He Shan Intelligent Machinery Co., Ltd. shows that the control system is effective.
It can improve the construction efficiency, accuracy and pile-forming rate of the machine and improve the safety of the whole machine, and has a good application prospect.
2. Control system and related functions of static pile driver
2. 1 control system software and hardware and composition diagram
The system hardware adopts Finnish EPEC series CAN bus control system module. The control module is aimed at engineering practice.
In harsh environment (such as high vibration, large temperature change and humidity, etc. ), the controller is equipped with a high-performance microprocessor.
The device is suitable for automatic control of construction machinery. It integrates programmable controller, proportional amplifier, A-core module and relay output.
And other functions are integrated.
The controller has a large number of input and output points. It can not only be used as a multifunctional controller to drive electro-hydraulic proportional valve, but also drive various liquids.
Pressure cylinder, etc. , and can be used as an independent controller. Unlike traditional PLC, each I/O port of EPEC controller can be one.
Needles are versatile and can be used as switch input D, output switch control D or output pulse width modulation signal (PwM).
In order to control the proportional valve, the user can set the signal type of each port in the system in the control program, which makes the spirit of the controller
The activity is greatly enhanced. The controller has CAN bus interface, which CAN be connected with many standard CAN bus products at home and abroad.
Connect, or connect with other buses or host computers through gateway modules to form a large-scale system.
The software design adopts IEC 61131-3 language to program in cedesys integrated development environment to complete the software design, compilation,
Download, at the same time, you can connect EPECZo23 through CAN-USB adapter for debugging and monitoring, so that the program control can achieve the best effect.
The flow chart of the control program is shown in the following figure.
2.2 Automatic piling function
ZYJ series static pile drivers produced by Hunan He Shan Intelligent Machinery Co., Ltd. firstly clamp the main cylinder when piling.
Lift the pile box to the highest position, then the pile is clamped by the pile clamping cylinder on the pile clamping box, and then the main pressure cylinder extends out to generate strong pressure to press the pile in.
Foundation, until the end of the main cylinder stroke, the pile clamping cylinder is loosened and retracted. Then the master cylinder retracts again, lifting the pile box, and so on.
Circularly complete the actions of "clamping pile, pressing pile, loosening pile, clamping pile back …", and finally press the pile into the bearing stratum. In the low pressure stage, as long as
The master cylinder can work; In the post-loading pile pressing stage, the main pile pressing cylinder and the auxiliary pile pressing cylinder need to work simultaneously. If there is an abnormal situation and the pile needs to be lifted,
Then the pile is still clamped by the pile clamping cylinder, and the main pressure cylinder lifts the pile clamping box, so that the pile can be lifted. When manually driving piles, operate the pile clamping box every time.
Each cycle needs to operate the handle 4~6 times. Generally, a pile 12m needs about 6 cycles of operation. It can be seen that the operation is labor intensive.
Quite a degree.
The pile pressing operation valve group adopts electromagnetic reversing valve, and the panel is equipped with automatic pile pressing, inching pile pressing, inching pile lifting and inching pile clamping.
Sheet piling station, touch the five buttons of the paper loosening station. The function of each button is as follows:
Inching pile pressing: operate the pile pressing cylinder downwards for debugging and hole alignment.
Inching pile lifting: operate the pile clamping box to rise, which is used for debugging and hole alignment.
Inching pile clamping: inching pile clamping box to clamp piles.
Inching loose pile: inching loose pile and clamping box.
Automatic piling: by analyzing the pressure at this time, automatically switch between fast pressure mode and slow pressure mode, and decide whether to apply force according to the piling termination conditions. oneself
Complete the four processes of pile clamping, pile pressing, pile loosening and pile lifting, and determine the number of automatic circulation processes according to the records of pile pressing depth system.
Each pile will stop automatically when it is pressed in place. Fig. 3 is the hydraulic schematic diagram of automatic piling.
Fig. 3 hydraulic schematic diagram of automatic pile pressing
2.3 Automatic leveling function
The four lifting cylinders are controlled by electromagnetic directional valves. The hydraulic schematic diagram is shown in Figure 4, and Figure 5 shows the plane inclination of the fuselage, 1, 2,
3 and 4 are the positions of the four lifting cylinders. Two angular displacement sensors are installed in the lifting cylinder.
Keep still during automatic leveling. Suppose there is an inclination angle in the x and y directions of the fuselage.
1 nearby, with the oil cylinder 1 as the reference point.
. , p, the side length of the fuselage in x and y directions.
The relative heights of points A, B, 2, 3 and 4 relative to point 1 are as follows:
HZ=asinQh3=asina is sinph4 dibsinp.
H3 is caused by the relative height between 2 o'clock and 4 o'clock, so it is only necessary to move cylinders 2 and 3 by h2 at the same time.
Then, cylinders 4 and 3 move a distance h4 at the same time, and the fuselage can be leveled. The fuselage leveling adopts the "successive approximation" method, and every time it moves,
Move the tilt distance by 50%, and then conduct A/D conversion again to find the tilt angle. , p, and then move the inclined distance by 50% until
}。 } Hurry up. 1 Call Shao. (A., P. To determine the allowable tilt angle of the fuselage according to the construction requirements), the leveling process is over.
The moving speed of the oil cylinder is QxA. When the cylinder area a and flow q are constant, the control of cylinder displacement can be transformed into electromagnetism.
Control of power-on time of reversing valve.
2.4 Alarm and control functions of flotation machine
In the process of pile sinking, when the pile tip meets the hard soil layer or sand layer, the pile sinking resistance suddenly increases, even exceeding the maximum value of the pile driver.
Under static pressure, the pile driver is lifted as a whole, which is called a flotation machine.
When the pile sinking resistance exceeds the maximum static pressure of the pile driver, if effective measures are not taken quickly, the pile driver will be greatly lifted and tilted.
Construction will lead to broken piles, even flying. Once flying, it will cause major equipment accidents.
In order to effectively prevent sitting on the ship and make full use of the self-weight of the long ship, it is necessary to give an alarm and control when floating the ship and disconnect the pile pressing circuit. famous book
After the test, the pressure changes in the upper and lower cavities of the lifting cylinder of the flotation machine are shown in Figure 6:
It can be seen that by testing the pressure in the upper cavity of the lifting cylinder, the pressure is reduced to close to zero, and the machine has floated. The controller detects the pressure.
By comparing the force signals, the pile pressing loop is cut off in time at the beginning of the flotation machine to protect the machine.
2.5 construction data automatic recording function
In the process of construction, the bearing capacity is calculated by recording the construction oil pressure of single pile; Through the inclination sensor installed on the pile clamping box
A device for recording the verticality of a single pile records the driving depth of the pile through an encoder installed on the pile pressing frame. The above data is automatically stored.
Form a report in the controller, which can be downloaded to the supervisor to check the construction quality.
3. Conclusion
After adding the mechatronics control system, the He Shan intelligent static pile driver improves the working efficiency and reduces the labor intensity.
It improves the construction quality and changes the image of the hydrostatic pile driver, which is well received by users.
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