The Key Technology Research On Design And Application Of High Speed Piezoelectric Shape Measuring Roll

As the economic development of our country enters into the new stage,the steel industry has entered the industry transition period after rapid development.Cold rolled strip,especially high strength automobile plate,coating plate and other high-end products,has become the key field of industry competition.As the key index of the high level strip,flatness detection and control technology of the cold rolled strip has received great attention from the industry.Shape meter is the "eye" of shape online detection,which is the premise of realizing the online detection and closed loop control.Therefore,it is one of the important symbols of enterprise competitiveness that whether to configure the shape meter with the ability of closed loop control.However,for a long time,the domestic large state-owned enterprises still imports shape meter,the introduction and maintenance costs are extremely expensive.Small and medium-sized enterprises can not install the flatness detection system because of the huge investment.The quality of products is difficult to improve,and it is not due to the high-end market.Due to the high accuracy of shape detection,the large electromagnetic interference in the service field and the complex working environment,and in order to meet the high-speed and continuous operation requirements of the modern cold rolling mill,the higher requirements for the stability,reliability and sustainability of the shape meter are put forward.Therefore,the development of shape meter has great technical difficulty and challenge.At present,only a few countries and institutions in the world have the technology research and development ability,and formed two main industrial shape meter based on piezomagnetic and piezoelectric sensors.In order to fill the gaps in the field of piezoelectric shape meter development in our country,to realize the independent development of piezoelectric shape meter instrument and to reverse the unfavorable situation that the high-end testing instruments in steel industry of our country rely on the import for a long time,it is urgent to solve the key technical problems in design and industrial applications.The development of shape meter involves many technical contents such as sensor parameter selection,roller body and load transfer structure design,precise assembly process,high speed acquisition and transmission processing of micro electrical signal,calibration curve and calibration compensation.This paper focuses on the mechanical detection principle of piezoelectric sensors and the characteristics of high sensitivity under the conditions of detecting dynamic load,non static output and high speed,through theoretical analysis,numerical simulation and experimental research,focusing on sensor parameter selection,flexible transmission force structure design,assembly process development,quasi-industrial performance testing and field application analysis and other key technical issues,to promote the localization and industrialization process of high-speed piezoelectric shape meter.Firstly,the shock dynamics and mechanical-electrical coupling model of multi contact body with roll body,piezoelectric sensor and elastic force transmission structure are established.The influence of load transfer characteristics of pulse width,pulse amplitude,area of action,load position and wrap angle,strip tension,strip delivery speed,effective strip width and other parameters,by changing the parameters for numerical simulation,was studied respectively under the condition of impact loading and strip loading.The theoretical basis and parameter design specification are laid for the design of the elastic force transmission structure and the selection of the piezoelectric sensors.Secondly,due to the particularity of the shape meter structure,it often does not have the conditions of repeated disassembly and assembly,which brings difficulties to the experimental adjustment and modification of the assembly process and structural parameters and greatly increases the trial production cost.In order to realize the assembly process experiment,the single-loop test system of piezoelectric shape analyzer was designed independently.The influence law of the assembly parameters such as pre tightening force of piezoelectric sensor and assembly of roller ring on the load transfer characteristics of a piezoelectric sensor is analyzed.The optimum parameters of the assembly process are determined,and the correctness of the second chapter finite element simulation is verified.Then,the dynamic calibration,signal coupling analysis and influencing factors compensation of each channel of the piezoelectric shape instrument are realized by using the international universal lever equivalent pressure calibration method.In order to make up for the shortage of the traditional lever equivalent pressure calibration method in the single loading mode,based on strip winding structure and axial mobile tension regulating mechanism,a set of quasi industrialization test platform for flatness detection is designed independently.Combined with the finite element simulation of roller loading,the analytical model of the front tension distribution of strip is established,and the construction of any front tension of the end plate is realized,which meets the requirements of off-line test and evaluation of the piezoelectric shape tester,and ensures the accuracy and reliability of online detection.Finally,based on the above research results,combined with the requirements of 900 UCM mill shape detection in a domestic factory,the design,manufacture,calibration analysis and site installation and debugging of the internal closed high speed piezoelectric shape meter have been completed independently.Through the analysis of the fault free running state and the flatness detection accuracy of the strip shape industrial field,it is determined that the piezoelectric shape tester can reflect the true shape of the strip and meet the requirement of spot shape inspection.It is also proved that the design of the piezoelectric shape meter is reasonable,which provides the conditions for the close loop detection and control of the high speed plate shape of cold rolling strip.