Bolt dynamic stress test analysis device based on simulated working condition

Abstract

The invention discloses a bolt dynamic stress test and analysis device based on simulated working conditions, and the device comprises a vibration simulator which is used for testing the influence of the vibration frequency of a to-be-tested bolt on the stress of the bolt; the bolt fixing device is combined with the wrench to realize the control on the torsion force when the bolt stress test is carried out; the controllable constant-temperature and constant-humidity chamber is used for generating corresponding temperature and humidity during bolt stress testing and testing the influence of the temperature and humidity in the corresponding environment on the bolt stress to be tested; the ultrasonic generator is used for setting a to-be-measured bolt material and length parameters; and the industrial personal computer is used for controlling the vibration simulator, the controllable constant temperature and humidity chamber, the bolt fixing device, the ultrasonic stress sensor and the ultrasonic generator and collecting and recording stress data of the ultrasonic generator in real time. Stress signals are collected in real time, control software automatically records bolt stress, operation is convenient, manual operation is reduced, and testing efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of bolt stress testing, and in particular to a bolt dynamic stress testing and analysis device based on simulated working conditions. Background Art

[0002] Bolts, as a fastener, connect two or more parts tightly together and are widely used in various industries. In fields with high safety requirements, such as roads and bridges, space shuttles, and automobile manufacturing, the quality requirements for bolts are extremely strict. Before formal use, the bolts need to be simulated and tested to ensure that the quality performance meets the standards.

[0003] Bolt stress is an important performance indicator of bolt quality. It refers to the force generated when the bolt is stretched or compressed to produce significant plastic deformation. The unit is Newton / square meter (N / m 2 ). Too little bolt stress will lead to loose connections; when the stress exceeds the loadable stress, the bolt will break. The loadable stress of the bolt is not only related to its own internal factors, such as materials, processing technology and installation methods, but also to the external use environment, such as temperature, vibration frequency and torque.

[0004] At present, most bolt stress testing methods and equipment use hydraulic cylinder extrusion to make the bolt produce compression deformation, and then use ultrasonic detectors to measure the bolt stress, such as the patent document with publication number CN119164524A. However, in actual use, bolts are tightened by wrenches to produce tensile deformation, and may be in a high temperature and high-frequency vibration environment. For example, subway linear motors are in a high temperature and high-frequency vibration environment for a long time. These environmental factors will accelerate the wear and failure of fasteners, and even cause the overall structure of the motor to loosen, crack, and break.

[0005] Therefore, this type of stress testing method and equipment does not consider and analyze the influence of external factors such as temperature, vibration frequency and torque on stress, and it is difficult to test the load-bearing stress of the bolt under real working conditions. It usually relies on manual recording, introduces human errors, and cannot measure stress dynamically and continuously, which has certain limitations. In addition, the working temperature, vibration frequency and torque of the bolt are dynamically changing, and the bolt stress will also change accordingly. This change is a dynamic, nonlinear and continuous process. The above-mentioned patent document uses manual single measurement and recording, which is not only cumbersome to operate, but also fails to measure the bolt stress dynamically and continuously.

[0006] In order to overcome the limitations of the above methods, a bolt dynamic stress test and analysis device based on simulated working conditions was developed. The device can control factors such as temperature, vibration frequency and torque during bolt testing, simulate the actual use environment of the bolt, and measure the bolt stress dynamically, continuously and automatically, thereby reducing manual operation, improving detection efficiency and reducing detection errors. Summary of the invention

[0007] In order to solve the above technical problems, the purpose of the present invention is to provide a bolt dynamic stress testing and analysis device based on simulated working conditions, which is used to simulate and control the temperature, vibration frequency and torque of the bolt working environment, dynamically and continuously measure the bolt stress and record the stress change process, so that the test results are more in line with the actual working environment and more accurate.

[0008] The purpose of the present invention is achieved through the following technical solutions:

[0009] A bolt dynamic stress test and analysis device based on simulated working conditions, comprising:

[0010] Vibration simulator, bolt fixing device, controllable constant temperature and humidity chamber, ultrasonic stress sensor, ultrasonic generator and industrial computer;

[0011] The vibration simulator is used to test the influence of the vibration frequency of the bolt to be tested on the bolt stress;

[0012] The bolt fixing device is combined with a wrench to achieve torque control during bolt stress testing;

[0013] The controllable constant temperature and humidity chamber is used to generate corresponding temperature and humidity when implementing bolt stress testing, and to test the influence of temperature and humidity in the corresponding environment on the stress of the bolt to be tested;

[0014] The ultrasonic generator is used to set the material and length parameters of the bolt to be tested;

[0015] The industrial computer is used to control the vibration simulator, the controllable constant temperature and humidity chamber, the bolt fixing device, the ultrasonic stress sensor and the ultrasonic generator, and to collect and record the stress data of the ultrasonic generator in real time.

[0016] Furthermore, the vibration simulator is installed and fixed on the ground; and is composed of an eccentric motor, a buffer spring, a fixed installation platform and a flexible sealing component; the eccentric motor is used to generate different vibration frequencies, and test the stress influence of the bolt to be tested through different vibration frequencies.

[0017] Furthermore, the bolt fixing device is installed and fixed on a fixed installation platform, and the fixed installation platform is sealed and connected to the controllable constant temperature and humidity chamber through a flexible sealing component, which is used for controlling the temperature and humidity of the controllable constant temperature and humidity chamber.

[0018] Furthermore, the bolt to be tested is tightened on the bolt fixing device with an electric wrench; wherein the bolt fixing device is equipped with screw hole stations of various specifications for simultaneously testing stresses of corresponding specifications and corresponding to different tightening force states.

[0019] Furthermore, one end of the ultrasonic stress sensor is tightly connected to the bolt to be tested through a coupling agent, and the other end is connected to the ultrasonic generator.

[0020] Furthermore, the industrial computer is connected to the vibration simulator, the controllable constant temperature and humidity chamber, the ultrasonic stress sensor and the ultrasonic generator through connecting lines.

[0021] Furthermore, the ultrasonic generator is connected to an industrial computer and transmits stress data to the industrial computer.

[0022] Compared with the prior art, one or more embodiments of the present invention may have the following advantages:

[0023] Through hardware structures such as constant temperature chamber, vibration simulator and bolt fixing bracket, it is possible to control relevant factors such as test temperature, vibration frequency and torque when measuring bolt stress, simulate the real working environment of the bolt, and make the measurement results more in line with the actual situation and more accurate.

[0024] By connecting hardware such as the constant temperature chamber, vibration simulator and ultrasonic generator through an industrial computer, the changes in temperature, vibration and torque can be controlled, and dynamic and continuous testing and analysis of changes in bolt stress can be achieved.

[0025] The stress signal is collected in real time, and the control software automatically records the stress of the bolt. It is easy to operate, reduces manual operation, and improves test efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a structural diagram of a bolt dynamic stress test and analysis device based on simulated working conditions;

[0027] Figure 2 yes Figure 1 The front view structural diagram of the device shown;

[0028] Figure 3 yes Figure 1 The left side structural schematic diagram of the device shown.

[0029] Among them, 1. Vibration simulator; 2. Bolt fixing bracket; 3. Bolt to be tested; 4. Ultrasonic stress sensor; 5. Controllable constant temperature and humidity chamber; 6. Industrial computer; 7. Ultrasonic generator;

[0030] 1-1. Eccentric motor; 1-2. Buffer spring; 1-3. Fixed installation platform; 1-4. Flexible sealing component. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below in conjunction with embodiments and drawings.

[0032] like Figure 1 As shown, a bolt dynamic stress test and analysis device based on simulated working conditions includes a vibration simulator, a bolt fixing device, a controllable constant temperature and humidity chamber, an ultrasonic stress sensor, an ultrasonic generator, and an industrial computer;

[0033] The vibration simulator is used to test the influence of the vibration frequency of the bolt to be tested on the bolt stress;

[0034] The bolt fixing device, combined with the wrench, can control the torque during the bolt stress test;

[0035] The controllable constant temperature and humidity chamber is used to generate the corresponding temperature and humidity when realizing the bolt stress test, and to test the influence of temperature and humidity on the stress of the bolt to be tested in the corresponding environment; the higher the ambient temperature and the worse the environment, the greater the influence on the service life of the bolt, and the preload force will become smaller and smaller. The stress inside the bolt may increase (before reaching the fatigue limit) or decrease (when exceeding the fatigue limit).

[0036] Ultrasonic generator, used to set the material and length parameters of the bolt to be tested;

[0037] The industrial computer is used to control the vibration simulator, the controllable constant temperature and humidity chamber, the bolt fixing device, the ultrasonic stress sensor and the ultrasonic generator, and to collect and record the stress data of the ultrasonic generator in real time.

[0038] like Figure 1-3 As shown, the vibration simulator 1 is composed of an eccentric motor 1-1, a buffer spring 1-2, a fixed installation platform 1-3 and a flexible sealing component 1-4, and is used to test the influence of the vibration frequency of the bolt to be tested on the stress. The vibration simulator 1 is generally fixed on the ground by bolts, and the bolt fixing bracket 2 is fixed on the fixed installation platform 1-3. The fixed installation platform 1-3 is sealed and connected to the controllable constant temperature and humidity chamber 5 through the flexible sealing component 1-4 to ensure the controllable temperature and humidity controllability of the controllable constant temperature and humidity chamber 5. 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; the influence of the vibration frequency on the stress of the bolt 3 to be tested is tested by controlling the eccentric motor 1-1 to generate corresponding different vibration frequencies.

[0039] The bolt fixing bracket 2 is installed and fixed on the fixed installation platform 1-3. The bolt 3 to be tested is tightened on the bolt fixing bracket 2 by simulating the actual tightening of the bolt with an electric wrench. The bolt fixing bracket 2 is equipped with bolt hole stations of various specifications, which can simultaneously test the influence of corresponding specifications and corresponding different tightening force states on stress under different working environment conditions.

[0040] The ultrasonic stress sensor 4 is tightly attached to the bolt 3 to be tested through a coupling agent, and the other end is connected to the ultrasonic generator 7, and the ultrasonic generator 7 is connected to the industrial computer 6.

[0041] The controllable constant temperature and humidity chamber 5 is used to generate corresponding temperature and humidity, and the influence of temperature and humidity on the stress of the bolt 3 to be tested under the corresponding working environment is tested.

[0042] Among them, the bolt stress test requirements and test process are as follows:

[0043] When testing bolt stress, simple stress testing can no longer reflect the actual working state of the bolt. The selected bolt needs to be tested for working conditions before selection and installation. The present invention uses a constant temperature control room to control the temperature and humidity in the test space to the required state. For example, for the fixing bolts of the linear motor of a subway train, the actual operating temperature can reach up to 180°C, and the ambient humidity can reach 70%-80%. The bolt must meet the requirements of continuous work in this state. Therefore, by using a constant temperature and humidity chamber to raise the temperature to 180°C and maintain it, and the humidity to maintain a fluctuating state of 70%-80%, the actual working environment of such bolts can be simulated. After the temperature and humidity reach the required working conditions, the selected bolts are installed and the installation preload is selected according to the actual situation. After installation, it is necessary to use a vibration simulator to simulate the operation of the subway train to achieve simulated control of the vibration frequency of the bolts. This vibration frequency varies with the speed of the train. The faster the speed, the higher the frequency, and the slower the speed, the lower the frequency. It is precisely because of the vibration simulator that the simulation of the vibration working condition can be achieved. In the present invention, the frequency change applied to the bolts is achieved by adjusting the vibration frequency of the vibration motor, thereby simulating the frequency of the actual operation of the train.

[0044] After the constant temperature room and vibration simulator parameters are set according to the bolt working condition parameters, the ultrasonic stress sensor is used to test the stress condition of the pre-tightened bolts, thereby realizing the simulated online stress measurement of the bolts, providing important data support for the subsequent bolt selection and installation.

[0045] The industrial computer 6 is connected to the vibration simulator 1, the controllable constant temperature and humidity chamber 5, the ultrasonic stress sensor 4 and the ultrasonic generator 7 through an RS232 connection line. The industrial computer 6 is pre-installed with a control test program to achieve 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 changes of the bolt 3 to be tested under different working environments.

[0046] The working process of the above device is:

[0047] The bolt 3 to be tested is tightened by an electric wrench and installed on the bolt fixing bracket; then the ultrasonic stress sensor 4 is connected to the bolt 3 to be tested through a coupling agent, and the bolt 3 to be tested is connected to the electric wrench; then the ultrasonic generator 7 is turned on to set parameters such as the material and length of the bolt 3 to be tested, and the industrial computer 6 is turned on 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 changes in bolt stress, so as to realize dynamic, continuous and automatic stress change measurement of the bolt 3 to be tested under different working environments.

[0048] Although the embodiments disclosed in the present invention are as above, the above contents are only embodiments adopted for facilitating the understanding of the present invention and are not intended to limit the present invention. Any technician in the technical field to which the present invention belongs can make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed in the present invention, but the patent protection scope of the present invention shall still be subject to the scope defined in the attached claims.

Claims

1. A bolt dynamic stress test and analysis device based on simulated working conditions, characterized in that: include: Vibration simulator, bolt fixing device, controllable constant temperature and humidity chamber, ultrasonic stress sensor, ultrasonic generator and industrial computer; The vibration simulator is used to test the influence of the vibration frequency of the bolt to be tested on the bolt stress; The bolt fixing device is combined with a wrench to achieve torque control during bolt stress testing; The controllable constant temperature and humidity chamber is used to generate corresponding temperature and humidity when implementing bolt stress testing, and to test the influence of temperature and humidity in the corresponding environment on the stress of the bolt to be tested; The ultrasonic generator is used to set the material and length parameters of the bolt to be tested; The industrial computer is used to control the vibration simulator, the controllable constant temperature and humidity chamber, the bolt fixing device, the ultrasonic stress sensor and the ultrasonic generator, and to collect and record the stress data of the ultrasonic generator in real time.

2. The bolt dynamic stress test and analysis device based on simulated working conditions according to claim 1 is characterized in that: The vibration simulator is installed and fixed on the ground; and is composed of an eccentric motor, a buffer spring, a fixed installation platform and a flexible sealing component; the eccentric motor is used to generate different vibration frequencies, and the stress influence of the bolt to be tested is tested through different vibration frequencies.

3. The bolt dynamic stress test and analysis device based on simulated working conditions according to claim 2 is characterized in that: The bolt fixing device is installed and fixed on a fixed installation platform, and the fixed installation platform is sealed and connected to the controllable constant temperature and humidity chamber through a flexible sealing component, and is used for controlling the temperature and humidity of the controllable constant temperature and humidity chamber.

4. The bolt dynamic stress test and analysis device based on simulated working conditions according to claim 1 is characterized in that: The bolt to be tested is tightened on the bolt fixing device with an electric wrench; wherein the bolt fixing device is equipped with screw hole stations of various specifications for simultaneously testing the stresses of corresponding specifications and corresponding to different tightening force states.

5. The bolt dynamic stress test and analysis device based on simulated working conditions according to claim 1 is characterized in that: One end of the ultrasonic stress sensor is tightly connected to the bolt to be tested through a coupling agent, and the other end is connected to the ultrasonic generator.

6. The bolt dynamic stress test and analysis device based on simulated working conditions according to claim 1 is characterized in that: 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.

7. The bolt dynamic stress testing and analysis device based on simulated working conditions according to claim 1 is characterized in that: The ultrasonic generator is connected to the industrial computer and transmits stress data to the industrial computer.

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