Bolt dynamic stress test analysis device based on simulated working condition

Abstract

The utility model discloses a bolt dynamic stress testing and analyzing device based on simulated working conditions. The bolt dynamic stress testing and analyzing device comprises a vibration simulator, a bolt fixing support, a bolt to be tested, an ultrasonic stress sensor, a controllable constant-temperature and constant-humidity chamber, an industrial personal computer and an ultrasonic generator. The vibration simulator is fixedly installed on the ground through bolts. The to-be-tested bolt is installed on the bolt fixing support. One end of the ultrasonic stress sensor is tightly attached to the bolt to be measured; the industrial personal computer is connected with the vibration simulator, the controllable constant-temperature and constant-humidity chamber, the ultrasonic stress sensor and the ultrasonic generator through connecting wires. The device provided by the utility model is used for simulating and controlling the temperature, the vibration frequency and the torsion of the bolt working environment, dynamically and continuously measuring the bolt stress and recording the change process of the stress, so that the test result is more in line with the real working environment and is more accurate.

Description

TECHNICAL FIELD

[0001] The utility model relates to bolt stress test technical field especially relates to a bolt dynamic stress test analysis device based on simulation working condition. BACKGROUND

[0002] Bolt, as a kind of fastener, two or more components are connected together tightly, is widely used in various trades and professions.In the field of high safety requirement, such as road bridge, space shuttle and automobile manufacturing industry, the quality requirement of bolt is extremely strict, needs to carry out simulation test to bolt before formal use, ensures that quality performance reaches standard.

[0003] Bolt stress is an important performance index that reflects the quality of bolt, is the force generated when bolt is subjected to tensile or compression and produces significant plastic deformation, unit is newton / square meter (N / m 2 ). Bolt stress is too small to lead to connection not firm, loose;When stress exceeds the bearable stress, it will lead to bolt fracture. Bolt bearable stress is not only related to internal factors, such as material, processing technology and installation mode, but also related to external use environment, such as temperature, vibration frequency and torsion.

[0004] At present, most bolt stress test methods and equipment are using the way of hydraulic cylinder extrusion to make bolt produce compression deformation, then using ultrasonic detector to measure bolt stress, such as patent literature with publication number CN119164524A. However, bolt is stretched by spanner in real use, and may be in high temperature, high frequency vibration environment, for example, subway linear motor is in high temperature, high frequency vibration environment for a long time, these environmental factors will lead to accelerated wear and failure of fastener, even cause the phenomenon such as looseness, cracking and fracture of the overall structure of motor.

[0005] Therefore, this type of stress test method and equipment do not consider and analyze the influence of external factors such as temperature, vibration frequency and torsion on stress, it is difficult to test the bearable stress of bolt under real working condition, and usually relies on manual record, introduces artificial error, cannot dynamically and continuously measure stress, has certain limitation. In addition, the working temperature, vibration frequency and torsion of bolt are dynamically changed, and the bolt stress will also change, and this change is a dynamic, nonlinear and continuous process, while the above-mentioned patent literature measures and records by artificial single time, not only operation is tedious, but also cannot dynamically and continuously measure bolt stress.

[0006] In order to overcome the limitations of the above method, a bolt dynamic stress test analysis device based on simulated working conditions is developed, which can control the temperature, vibration frequency and torque and other factors during the bolt test, simulate the real use environment of the bolt, dynamically, continuously and automatically measure the bolt stress, and achieve the purposes of reducing manual operation, improving detection efficiency and reducing detection error.

[0007] The current bolt stress test method and device analysis has the following problems:

[0008] (1) The existing method and device are all measured by the way of extrusion under ideal environment, without considering and controlling the temperature, vibration frequency and torque and other factors, so it is difficult to measure the maximum stress that the bolt can bear under real working conditions.

[0009] (2) It does not support dynamic and continuous measurement and recording of bolt stress. The bolt stress changes with the change of temperature, vibration frequency and torque, and it is a dynamic, continuous and nonlinear process. For example, the vibration frequency of the subway linear motor increases from static to high speed operation and then stabilizes, and the stress of the bolt on the motor also changes. Recording the change process of the stress can more effectively analyze the bolt stress. At present, the existing method and device cannot measure, record and analyze the dynamic change process of the stress.

[0010] (3) It relies on manual operation and recording, which is inconvenient and easy to introduce artificial error, resulting in low detection efficiency and inaccurate measurement results. SUMMARY

[0011] To solve the above technical problems, the purpose of the utility model is to provide a bolt dynamic stress test analysis device based on simulated working conditions, which can control the temperature, vibration frequency and torque and other factors during the bolt test, simulate the real use environment of the bolt, dynamically, continuously and automatically measure the bolt stress, and achieve the purposes of reducing manual operation, improving detection efficiency and reducing detection error.

[0012] The purpose of the utility model is realized by the following technical solutions:

[0013] A bolt dynamic stress test analysis device based on simulated working conditions comprises:

[0014] A vibration simulator, a bolt fixing support, a bolt to be tested, an ultrasonic stress sensor, a controllable constant temperature and humidity chamber, an industrial computer and an ultrasonic generator. The vibration simulator is fixed to the ground by a bolt. The bolt to be tested is installed on the bolt fixing support. One end of the ultrasonic stress sensor is closely attached to the bolt to be tested. The industrial computer is connected with the vibration simulator, the controllable constant temperature and humidity chamber, the ultrasonic stress sensor and the ultrasonic generator through connecting lines.

[0015] Further, the vibration simulator is composed of an eccentric motor, a buffer spring, a fixed mounting platform and a flexible sealing component.

[0016] Further, the bolt fixing support is fixedly mounted on the fixed mounting platform; and the fixed mounting platform is sealingly connected with the controllable constant temperature and humidity chamber through the flexible sealing component.

[0017] Further, the bolt to be tested is connected with an electric wrench, and the torque is controlled when the bolt stress test is realized through the bolt fixing support and the electric wrench.

[0018] Further, the other end of the ultrasonic stress sensor is connected with an ultrasonic generator.

[0019] Further, the ultrasonic generator is connected with an industrial computer.

[0020] Compared with the prior art, one or more embodiments of the present application can have the following advantages:

[0021] The device is used for simulating and controlling the temperature, vibration frequency and torque of the bolt working environment, dynamically and continuously measuring the bolt stress and recording the change process of the stress, so that the test result is more in line with the real working environment and more accurate. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a structural schematic view of a bolt dynamic stress test analysis device based on simulated working conditions;

[0023] Figure 2 is Figure 1 a front view schematic view of the device;

[0024] Figure 3 is Figure 1 a left view structural schematic view of the device.

[0025] Among them, 1, vibration simulator; 2, bolt fixing support; 3, bolt to be tested; 4, ultrasonic stress sensor; 5, controllable constant temperature and humidity chamber; 6, industrial computer; 7, ultrasonic generator;

[0026] 1-1, eccentric motor; 1-2, buffer spring; 1-3, fixed mounting platform; 1-4, flexible sealing component. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical scheme and advantages of the present application more clear, the following will combine embodiments and drawings to make further detailed description on the present application.

[0028] As Figures 1 to 3 shown, the structure of the bolt dynamic stress test analysis device based on simulated working conditions provided by the present application comprises:

[0029] Vibration simulator 1, bolt fixing support 2, bolt to be tested 3, ultrasonic stress sensor 4, controllable constant temperature and humidity chamber 5, industrial computer 6 and ultrasonic generator 7; the vibration simulator 1 is fixed on the ground by bolts; the bolt to be tested 3 is installed on the bolt fixing support 2; one end of the ultrasonic stress sensor 4 is closely attached to the bolt to be tested 3; the industrial computer 6 is connected with the vibration simulator 1, the controllable constant temperature and humidity chamber 5, the ultrasonic stress sensor 4 and the ultrasonic generator 7 through connecting lines.

[0030] The vibration simulator 1 is composed of an eccentric motor 1-1, a buffer spring 1-2, a fixed mounting platform 1-3 and a flexible sealing component 1-4, which is used to test the influence of vibration frequency on the stress of the bolt to be tested 3.

[0031] The bolt fixing support 2 is fixed on the fixed mounting platform 1-3; the fixed mounting platform 1-3 is sealingly connected with the controllable constant temperature and humidity chamber 5 through the flexible sealing component 1-4, which ensures the controllable temperature and humidity of the controllable constant temperature and humidity chamber, and at the same time, the vibration generated by the vibration simulator 1 is basically not transmitted to the controllable constant temperature and humidity chamber 5; by controlling the eccentric motor 1-1 to generate different vibration frequencies, the influence of vibration frequency on the stress of the bolt to be tested 3 is tested.

[0032] The controllable constant temperature and humidity chamber 5 generates corresponding temperature and humidity, which tests the influence of temperature and humidity on the stress of the bolt to be tested 3 in the corresponding working environment. The higher the environmental temperature, the worse the environment, the greater the influence on the service life of the bolt, and the smaller the pre-tightening force in the bolt, which may increase the stress inside the bolt (when the fatigue limit is not reached) or decrease the stress (when the fatigue limit is exceeded).

[0033] The bolt to be tested 3 is connected with an electric wrench, and the control of the torque during the bolt stress test is realized through the bolt fixing support 2 and the electric wrench. The bolt fixing support 2 is provided with bolt hole stations of various specifications, which can simultaneously test the influence of different working environment conditions on the stress under corresponding specifications and different torque tightening states.

[0034] Among them, the bolt stress test requirements and test process are as follows:

[0035] In the test of bolt stress, the pure stress test can not reflect the real working state of the bolt, and the working condition test of the selected bolt is needed before the bolt selection and installation. The embodiment utilizes the constant temperature control chamber to control the temperature and humidity in the test space to the required state. For example, for the fixing bolt of the metro train linear motor, the maximum temperature in the actual operation is 180℃, and the environmental humidity can reach 70%-80%. The bolt must meet the requirements of continuous operation in this state. Therefore, by using the constant temperature and humidity chamber, the temperature is increased to 180℃ and maintained, and the humidity is maintained at 70%-80% fluctuation state, so as to simulate the actual working environment of such bolt. After the temperature and humidity reach the required working condition, the selected bolt is installed and the pre-tightening force is selected according to the actual situation. After installation, the vibration simulator is used to simulate the running condition of the metro train to realize the vibration frequency simulation control of the bolt. The vibration frequency changes with the train speed, that is, the higher the speed, the higher the frequency, and the lower the speed, the lower the frequency. It is the vibration simulator that realizes the simulation of the vibration working condition. In the embodiment, the vibration frequency of the vibration motor is adjusted to realize the frequency change of the bolt, so as to simulate the frequency of the actual running condition of the train.

[0036] After the parameters of the constant temperature chamber and the vibration simulator are set according to the working condition parameters of the bolt, the ultrasonic stress sensor is used to test the stress condition of the pre-tightened bolt, so as to realize the simulated online stress measurement of the bolt and provide important data support for the subsequent bolt selection and installation.

[0037] The other end of the ultrasonic stress sensor 4 is connected with the ultrasonic generator 7.

[0038] The ultrasonic generator 7 is connected with the industrial computer 6. The industrial computer 6 is pre-installed with a control test program to realize the control of vibration, temperature and humidity, and to collect and record the stress data returned by the ultrasonic generator 7 in real time, so as to dynamically and continuously test the stress change of the measured bolt 3 under different working environments.

[0039] The working process of the above embodiment is as follows:

[0040] Firstly, the measured bolt 3 is tightened and installed on the bolt fixing support through the electric wrench; then the ultrasonic stress sensor 4 is connected with the measured bolt 3 through the coupling agent, and the measured bolt 3 is connected with the electric wrench; then the ultrasonic generator 7 is started to set the parameters such as the material and length of the measured bolt 3, and the industrial computer 6 is started to set the initial temperature, humidity and vibration frequency through the control software; the corresponding temperature, humidity and vibration frequency are adjusted through the control software to test, record and analyze the change of the bolt stress, so as to realize the dynamic, continuous and automatic stress change measurement of the measured bolt 3 under different working environments.

[0041] The hardware structure of the constant temperature chamber, the vibration simulator and the bolt fixing support provided by the device can control the related factors such as the test temperature, the vibration frequency and the torsion force when measuring the bolt stress, simulate the real working environment of the bolt, and make the measurement result more in line with the real situation and more accurate.

[0042] The hardware such as the constant temperature chamber, the vibration simulator and the ultrasonic generator is connected with the industrial computer, the changes of the temperature, the vibration and the torsion force can be controlled, and the dynamic and continuous test and analysis of the bolt stress change condition can be realized.

[0043] The stress signal is collected in real time, the stress of the bolt is recorded automatically by the control software, the operation is convenient, the manual operation is reduced, and the test efficiency is improved.

[0044] Although the embodiments disclosed by the utility model are as above, the content is only for the purpose of understanding the utility model and is not used to limit the utility model. Any person skilled in the art of the utility model can make any modification and change in the implementation form and details without departing from the spirit and scope of the utility model. The patent protection scope of the utility model is still subject to the scope defined by the attached claims.

Claims

1. A bolt dynamic stress test analysis device based on simulated working conditions, characterized in that, The device comprises a vibration simulator (1), a bolt fixing support (2), a bolt to be tested (3), an ultrasonic stress sensor (4), a controllable constant temperature and humidity chamber (5), an industrial computer (6) and an ultrasonic generator (7); the vibration simulator (1) is fixed on the ground by bolts; the bolt to be tested (3) is installed on the bolt fixing support (2); one end of the ultrasonic stress sensor (4) is closely attached to the bolt to be tested (3); the industrial computer (6) is connected with the vibration simulator (1), the controllable constant temperature and humidity chamber (5), the ultrasonic stress sensor (4) and the ultrasonic generator (7) through connecting lines.

2. The bolt dynamic stress test analysis device based on analog working condition according to claim 1, characterized in that, The vibration simulator (1) is composed of an eccentric motor (1-1), a buffer spring (1-2), a fixed mounting platform (1-3) and a flexible sealing component (1-4); The bolt fixing support (2) is fixed on the fixed mounting platform (1-3); the fixed mounting platform (1-3) is sealingly connected with the controllable constant temperature and humidity chamber (5) through the flexible sealing component (1-4).

3. The bolt dynamic stress test analysis device based on analog working condition according to claim 1, characterized in that, The bolt to be tested (3) is connected with an electric wrench, and the control of the torque is realized when the bolt stress test is carried out through the bolt fixing support (2) and the electric wrench.

4. The bolt dynamic stress test analysis device based on analog working condition according to claim 1, characterized in that, The other end of the ultrasonic stress sensor (4) is connected with the ultrasonic generator (7).

5. The analog condition based bolt dynamic stress test analysis device according to claim 1, wherein, The ultrasonic generator (7) is connected with the industrial computer (6).

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