阅读说明：本技术 基于声弹效应的大型高速回转装备装配紧固力测量方法 (Large-scale high-speed rotation equipment assembling fastening force measuring method based on acoustic-elastic effect ) 是由 谭久彬 刘永猛 孙传智 王晓明 刘恩晓 于 2019-11-20 设计创作，主要内容包括：本发明提出一种基于声弹效应的大型高速回转装备装配紧固力测量方法,工控机控制激光器发射脉冲激光,脉冲激光被分光镜分成两束,数据采集卡将采集到的信号传至工控机进行处理,计算出Δt<Sub>0</Sub>；所有螺栓紧固后,对第一个螺栓进行测量,计算出Δt<Sub>1</Sub>,求出该螺栓的紧固力F<Sub>1</Sub>,工控机控制精密回转台转动一定角度,对第二个螺栓进行测量,计算出Δt<Sub>2</Sub>,求出该螺栓的紧固力F<Sub>2</Sub>,直至转子装配体回转一周,完成若干个螺栓紧固力的测量。解决了现有技术的航空发动机转子装配紧固力难以直接测量、测量效率低且会对转子表面造成腐蚀等问题,提出一种基于声弹效应的大型高速回转装备装配紧固力测量方法,实现航空发动机转子装配紧固力的直接、高效率和高精度测量。(The invention provides a large-scale high-speed rotation equipment assembling fastening force measuring method based on acoustic-elastic effect 0 (ii) a After all the bolts are fastened, measuring the first bolt and calculating delta t 1 Determining the fastening force F of the bolt 1 The industrial personal computer controls the precise rotary table to rotate a certain angle, measures the second bolt and calculates delta t 2 Determining the fastening force F of the bolt 2 And measuring the fastening force of the plurality of bolts until the rotor assembly body rotates for a circle. The method solves the problems that the assembly fastening force of the rotor of the aircraft engine in the prior art is difficult to directly measure, the measurement efficiency is low, the surface of the rotor can be corroded and the like, provides the method for measuring the assembly fastening force of the large-sized high-speed rotating equipment based on the acoustic-elastic effect, and realizes the direct, high-efficiency and high-precision measurement of the assembly fastening force of the rotor of the aircraft engine.)

1. A large-scale high-speed rotation equipment assembly fastening force measuring method based on a sound-elastic effect is characterized by comprising the following steps:

firstly, placing a rotor assembly (9) on a precision rotary table (11) and adjusting the position of the rotor assembly to enable the rotor assembly (9) to be consistent with the rotary axis of the precision rotary table (11), and fixing the rotor assembly (9) through a clamp (10);

secondly, the laser (1) and the spectroscope (2) are adjusted in position and posture, so that laser emitted by the laser (1) can penetrate through the spectroscope (2) to irradiate the center of the upper end face of the bolt (7);

thirdly, the second photoelectric detector (8) adjusts the position and the posture to enable the second photoelectric detector to receive the ultrasonic signal of the upper end face of the tested bolt (7);

fourthly, the position and the posture of the attenuation sheet (3), the focusing lens (4) and the first photoelectric detector (5) are adjusted, so that the laser beams split by the spectroscope (2) can pass through the attenuation sheet (3) and the focusing lens (4) to be received by the first photoelectric detector (5);

fifthly, before all the bolts (7) are not fastened, an industrial personal computer (13) controls a laser (1) to emit pulse laser, the pulse laser is divided into two beams by a spectroscope (2), one beam of the pulse laser passes through an attenuator (3) and then is received by a first photoelectric detector (5) through a focusing lens (4) and converted into an electric signal, the electric signal is transmitted into a data acquisition card (6) to be used as acquisition trigger of an ultrasonic signal, the other beam of the pulse laser irradiates the center of the upper end face of the bolt (7), ultrasonic waves are generated on the upper end face of the bolt (7), the ultrasonic waves are transmitted downwards along the axial direction of the bolt (7) after being generated until being transmitted to the lower end face of the bolt (7) and then reflected, the ultrasonic signals are transmitted upwards to the upper end face of the bolt (7) along the axial direction of the bolt (7), the ultrasonic signals transmitted to the upper end face of the bolt (7) are received by, the data acquisition card (6) transmits the acquired signals to an industrial personal computer (13) for processing, and calculates the time difference delta t between the time when the trigger signal of the first photoelectric detector (5) is received and the time when the ultrasonic signal of the second photoelectric detector (8) is received₀；

Sixthly, after all the bolts (7) are fastened, the industrial personal computer (13) sends an instruction to the laser (1) to emit pulse laser, the propagation route of the pulse laser and the generation and receiving process of the ultrasonic signal are the same as the fifth step, and the time difference delta t between the time when the trigger signal of the first photoelectric detector (5) is received and the time when the ultrasonic signal of the second photoelectric detector (8) is received is calculated₁；

A seventh step of determining the fastening force F of the bolt (7) to be tested according to the propagation time difference of the ultrasonic wave before and after fastening and the stress coefficient of the bolt₁；

Eighthly, the industrial personal computer (13) controls the precision rotary table (11) to rotate for a certain angle, the industrial personal computer (13) sends an instruction to the laser (1) to emit pulse laser after the rotation is finished, the propagation route of the pulse laser and the generation and receiving process of the ultrasonic signal are the same as the fifth step, and the time difference delta t between the time when the trigger signal of the first photoelectric detector (5) is received and the time when the ultrasonic signal of the second photoelectric detector (8) is received is calculated₂；

A ninth step of determining a fastening force F of the bolt based on a propagation time difference of the ultrasonic wave before and after fastening and a stress coefficient of the bolt₂；

And step ten, repeating the step nine until the rotor assembly body (9) rotates for a circle, and finishing the measurement of the fastening force of the plurality of bolts.

2. The laser ultrasound-based large-scale high-speed slewing equipment assembly fastening force measuring device of claim 1, wherein a calculation formula of the bolt fastening force Fi is Fi-sx σ i, where S is a stress sectional area of the bolt and σ i is a bolt fastening stress;

the calculation formula of the bolt fastening stress sigma i is that sigma i is K multiplied by delta T_iWhere K is a coefficient relating to the geometry and the material type of the bolt, determined by calibration tests, Δ T_iThe propagation time difference of the ultrasonic wave before and after the ith bolt is fastened;

the calculation formula of the propagation time difference of the ultrasonic waves before and after fastening is delta T_i＝Δt_i-Δt₀。

Technical Field

The invention relates to an assembly fastening force measuring method, in particular to a large-scale high-speed rotating equipment assembly fastening force measuring method based on a sound-elastic effect, and belongs to the technical field of ultrasonic measurement.

Background

The core engine system of the aircraft engine is formed by assembling multiple stages of rotors, and the assembling quality among the rotors at all stages has great influence on the performance of the aircraft engine. If the pretightening force of the bolt group is uneven, the bolt connection surface of the rotor is irregularly deformed, the coaxiality of the assembled rotor is easy to exceed the standard, and the unbalance exceeds the required value. After the engine works for a long time, the initial pretightening force of the bolt is reduced due to the creep phenomenon of the pretightening force of the bolt, the nonuniformity of the pretightening force of the bolt is amplified, the rigidity uniformity of the rotor is poor, the working performance of the rotor is greatly influenced when the rotor is subjected to axial load, the service life of the rotor is shortened, and the safety of the engine is reduced. Therefore, the assembly fastening force of the engine rotor is required to be precisely measured, and the assembly can be precisely carried out only when the measurement is precise.

The current commonly used bolt assembling and fastening force measuring methods include a torque pulling method, a resistance strain gauge electrical measurement method, a photorefractive method and the like. The torque pulling method is used for indirectly controlling the pretightening force of the bolt through torque, so that the measured value has larger error; the electrical measurement method of the resistance strain gauge obtains the axial stress of the bolt by measuring the surface strain of the bolt, but the surface of the bolt generates certain shear deformation when the bolt is screwed down, so that the measurement result has deviation from the actual axial stress; the photorefractive method is only limited to laboratory conditions and cannot be widely applied to on-line measurement in engineering. The above-mentioned testing method is limited by various aspects such as measuring accuracy, installation condition and field environment, so that it is difficult to implement on-line measurement in engineering.

The ultrasonic bolt assembling and fastening force measuring method obtains the bolt axial stress by measuring the change of the ultrasonic wave speed in the bolt, further obtains the bolt assembling and fastening force, and has the characteristics of no damage to a measured object, high measuring speed, high measuring precision and the like, so that domestic and foreign scholars carry out extensive research on the ultrasonic measuring method. The traditional ultrasonic technology mostly adopts a contact transducer, in order to ensure high sensitivity and reliability, various ultrasonic couplants are generally used, certain transit time is needed when ultrasonic waves pass through the couplants, interference harmonic waves can be generated, unstable factors are brought to measurement, extra workload can be added by using the couplants, the measurement efficiency is low, and certain corrosion and damage can be caused to the surface of a workpiece more seriously, so that the traditional ultrasonic method is limited in practical application.

Disclosure of Invention

The invention provides a method for measuring the assembly fastening force of large-scale high-speed rotating equipment based on an acoustic-elastic effect, which aims to solve the problems that the assembly fastening force of an aircraft engine rotor in the prior art is difficult to directly measure, the traditional ultrasonic method is low in measurement efficiency and can cause corrosion to the surface of a rotor, and the like, and the direct, high-efficiency and high-precision measurement of the assembly fastening force of the aircraft engine rotor is realized.

The invention provides a large-scale high-speed rotation equipment assembling fastening force measuring method based on a sound-elastic effect, which specifically comprises the following steps:

the method comprises the following steps that firstly, a rotor assembly body is placed on a precision rotary table and the position of the rotor assembly body is adjusted, so that the rotor assembly body is consistent with the rotary axis of the precision rotary table, and the rotor assembly body is fixed through a clamp;

secondly, the laser and the spectroscope are adjusted in position and posture, so that laser emitted by the laser can penetrate through the spectroscope and irradiate the center of the upper end face of the bolt;

thirdly, adjusting the position and the posture of a second photoelectric detector to enable the second photoelectric detector to receive ultrasonic signals of the upper end face of the bolt;

fourthly, the attenuation sheet, the focusing lens and the first photoelectric detector adjust the position and the posture, so that the laser beam split by the spectroscope can pass through the attenuation sheet and the focusing lens to be received by the first photoelectric detector;

fifthly, before all the bolts are not fastened, the industrial personal computer sends an instruction to the laser to emit pulse laser, the pulse laser is divided into two beams by the spectroscope, one beam of the pulse laser passes through the attenuation sheet and then is received by the first photoelectric detector through the focusing lens and converted into an electric signal to be transmitted into data acquisitionThe card is used as acquisition trigger of an ultrasonic signal, another beam irradiates the center of the upper end face of the bolt, ultrasonic waves are generated on the upper end face of the bolt due to the thermoelastic effect, the ultrasonic waves are transmitted downwards along the axial direction of the bolt after being generated until being transmitted to the lower end face of the bolt and then reflected, the ultrasonic waves are transmitted upwards along the axial direction of the bolt to the upper end face of the bolt, the ultrasonic signals transmitted to the upper end face of the bolt are received by a second photoelectric detector and converted into electric signals to be transmitted to a data acquisition card, the data acquisition card transmits the acquired signals to an industrial personal computer for processing, and the time difference delta t between the time when the trigger signal of the first photoelectric detector is received and the time₀；

Sixthly, after all the bolts are fastened, the industrial personal computer sends an instruction to the laser to emit pulse laser, the propagation route of the pulse laser and the generation and receiving process of the ultrasonic signal are the same as those in the fifth step, and the time difference delta t between the time when the trigger signal of the first photoelectric detector is received and the time when the ultrasonic signal of the second photoelectric detector is received is calculated₁，

A seventh step of determining a fastening force F of the bolt based on a propagation time difference of the ultrasonic wave before and after fastening and a stress coefficient of the bolt₁；

Eighthly, the industrial personal computer controls the precision rotary table to rotate by a certain angle, the industrial personal computer sends an instruction laser to emit pulse laser after the rotation is finished, the propagation route of the pulse laser and the generation and receiving process of the ultrasonic signal are the same as the fifth step, and the time difference delta t between the trigger signal of the first photoelectric detector and the ultrasonic signal of the second photoelectric detector is calculated₂；

A ninth step of determining a fastening force F of the bolt based on a propagation time difference of the ultrasonic wave before and after fastening and a stress coefficient of the bolt₂；

And step ten, repeating the step nine until the rotor assembly body 9 rotates for a circle, and finishing the measurement of the fastening force of the plurality of bolts.

Preferably, the calculation formula of the bolt fastening force Fi is Fi ═ sx σ i, where S is a stress sectional area of the bolt and σ i is a bolt fastening stress;

the calculation formula of the bolt fastening stress sigma i is that sigma i is K multiplied by delta T_iWhere K is a coefficient relating to the geometry and the material type of the bolt, determined by calibration tests, Δ T_iThe propagation time difference of the ultrasonic wave before and after the ith bolt is fastened;

the calculation formula of the propagation time difference of the ultrasonic waves before and after fastening is delta T_i＝Δt_i-Δt₀。

The method for measuring the assembling fastening force of the large-scale high-speed rotating equipment based on the acoustic-elastic effect has the beneficial effects that:

1. the large-scale high-speed rotating equipment assembling fastening force measuring method based on the acoustic-elastic effect adopts the laser and the photoelectric detector to respectively realize the excitation and the receiving of the ultrasonic method, can avoid using a liquid coupling agent which is necessary in the traditional ultrasonic method, thereby eliminating the corrosion and the pollution of the coupling agent to the surface of the bolt, simultaneously, the excitation and the receiving of the acoustic-elastic effect are instantly finished, the rapid and real-time measurement can be realized, and the anti-interference capability is stronger.

2. The method for measuring the assembling fastening force of the large-sized high-speed rotating equipment based on the acoustic-elastic effect adopts the precise rotating table to drive the rotor assembly body to rotate so as to realize the measurement of all bolts, has high automation degree and is beneficial to improving the measurement efficiency.

Drawings

FIG. 1 is a schematic structural diagram of a device corresponding to the method for measuring the assembling fastening force of the large-scale high-speed rotating equipment based on the acoustic-elastic effect;

in the figure: 1-a laser; 2-a spectroscope; 3-an attenuation sheet; 4-a focusing lens; 5-a first photoelectric detector; 6-a data acquisition card; 7-bolt; 8-a second photodetector; 9-a rotor assembly; 10-a clamp; 11-a precision turret; 12-a turntable base; and 13-an industrial personal computer.

Detailed Description

The following detailed description of embodiments of the invention is provided in conjunction with the appended drawings: