Time： 2019-11-14 19:20:09
Displacement sensor is widely used in displacement measurement and test of prestressed tension equipment. Commonly used are potentiometer principle linear displacement sensor, pull rope displacement sensor and magnetostrictive displacement sensor. Potentiometer principle linear displacement sensor is widely used in prestressed tensioning equipment because of its simple structure, high precision, good stability and low cost.
In order to improve the service performance of engineering structural components, the area under the external load is stressed in advance during the construction period, which can partially offset the tensile stress, bending moment or compressive stress caused by the load, delay the occurrence of cracks, increase the durability of components, and avoid structural damage. It is commonly used in concrete structures. It is possible to improve the performance of the structure and the bearing capacity of the structure by using the prestressed principle and technology reasonably.
The traditional prestressed tensioning equipment is basically composed of oil pump, tensioning jack and its accessories. During construction, oil is supplied to the jack through the electric oil pump, the jack piston drives the tool anchor to drive the steel strand to extend and apply prestress to the beam body, the load of the steel strand is converted by the pressure value on the oil pump, and the elongation of the steel strand is calculated by measuring the stroke of the jack piston with a steel ruler. Traditional prestressed tension construction has many disadvantages, such as large tension control error, large measurement error, unmeasurable retraction value, low synchronization rate of both ends; unable to realize the dual control of tension and, lack of reliable process control means and effective detection and evaluation methods, which are gradually replaced by intelligent tension technology.
Prestressed program-controlled (intelligent, CNC) tensioning technology refers to the automation control of tensioning operation based on computer intelligence and sensor technology. The modern program-controlled tension system is composed of program-controlled host and operation front-end. The front end of the work includes the measurement and control circuit, oil pump, Jack, sensor and other components. The host controls one or more measurement and control front ends according to preset tension parameters. The front end controls the oil pump motor through the variable frequency output stepless speed regulation according to the instructions of the main engine, and at the same time monitors the working pressure of the jack and the elongation value of the steel strand to feed back to the main engine. According to the feedback data, the host calculates the next command to continue to remote control the front end, thus forming a closed-loop control. The pre-stressed tension program control system takes the tension as the main control index and the elongation as the auxiliary control index, so as to realize the double control of the tension and the elongation value, and ensure that the tension and the elongation at both ends of the whole process of tension are highly synchronized.
KPM micro twisted linear displacement sensor, fish eye twisted at both ends, no special requirements for installation and alignment, suitable for small travel, measurement process swing occasions. Sensor absolute position measurement type, output DC voltage signal. The standard analog signal or digital signal can also be converted by adding sensor transmission module. KPM displacement sensor is used for displacement measurement and control of prestressed Jack and contact structure design. It has the advantages of high precision, good stability and high cost performance, and becomes the mainstream of the market.