System and method for calculating and setting bolt tightening monitoring torque and angle

Abstract

The invention discloses a system and method for calculating and setting bolt tightening monitoring torque and angle, and the method comprises the steps: setting a first monitoring torque value according to a final tightening torque value, and setting a first monitoring angle value according to the effective screwing length and thread specification of a bolt; a second monitoring torque value is set according to the final screwing torque value, and a second monitoring angle value is set according to the thread specification; according to a preset monitoring torque value and a preset monitoring angle value, data statistics is carried out on a tightening result, a normal distribution principle is used for multiple times to carry out analysis and calculation on statistical data to obtain a corrected monitoring torque value and a corrected monitoring angle value, and the bolt tightening working condition is monitored according to the corrected monitoring torque value and the corrected monitoring angle value. Workpiece defects can be found in time in the workpiece tightening process, scrapping and reworking caused by continuous tightening are avoided, and meanwhile thread slipping caused by excessive tightening of the workpiece can be avoided when workpiece tightening is about to be finished.

Description

Technical Field

[0001] The invention relates to the field of bolt tightening monitoring, and in particular to a system and method for calculating and setting torque and angle of bolt tightening monitoring. Background Art

[0002] In the assembly production line, there are various bolt tightening conditions. In order to improve the qualified rate of product tightening, the tightening strategy is optimized to avoid rework and scrap caused by bolt tightening. In the current tightening process, there is already a way to monitor the tightening torque and tightening angle during the tightening process, so as to find the quality defects of the workpiece in the tightening process as early as possible, terminate the tightening process in time, and perform rework and inspection. However, the existing technical solution has the problem of unreasonable monitoring values ​​set for angle monitoring and torque monitoring during the tightening process, which will cause the workpiece to be scrapped. Summary of the invention

[0003] The present invention provides, on the one hand, a method for calculating and setting a bolt tightening monitoring torque and angle, and on the other hand, provides a system for calculating and setting a bolt tightening monitoring torque and angle. The method and system can set reasonable and accurate monitoring torque values ​​and monitoring angle values, and can monitor the tightening torque and tightening angle during the tightening process, so as to early detect quality defects of the workpiece during the tightening process, terminate the tightening process in time, and perform repair and inspection.

[0004] To achieve this purpose, the present invention provides a method for calculating and setting a bolt tightening monitoring torque and angle, which comprises:

[0005] The first monitoring torque value is set according to the final tightening torque value, and the first monitoring angle value is set according to the effective screwing length of the bolt and the thread specification; the second monitoring torque value is set according to the final tightening torque value, and the second monitoring angle value is set according to the thread specification;

[0006] According to the first monitoring torque value, the first monitoring angle value, the second monitoring torque value and the second monitoring angle value, data statistics are performed on the tightening results of the workpiece, and the normal distribution principle is used multiple times to analyze and calculate the statistical data to obtain the corrected first monitoring torque value, the first monitoring angle value, the second monitoring torque value and the second monitoring angle value, and the bolt tightening condition is monitored according to the corrected first monitoring torque value, the first monitoring angle value, the second monitoring torque value and the second monitoring angle value.

[0007] Furthermore, the method for obtaining the first monitoring torque value and the first monitoring angle value includes: the first monitoring torque value is set to F1=T*(45%~50%), T is the final tightening torque value; the first monitoring angle value α=(M / m*360-360)°, M is the effective screwing length value of the bolt, and m is the thread specification.

[0008] Furthermore, the actual value of the first monitoring angle value α cannot be greater than the calculated value.

[0009] Furthermore, the method for obtaining the second monitoring torque value and the second monitoring angle value includes: setting the second monitoring torque value to F2=T*(95%-100%); the second monitoring angle value β=(m*360 / 2)°, where m is the thread specification.

[0010] Furthermore, the actual value of the second monitoring angle value β cannot be less than the calculated value.

[0011] Furthermore, according to the set first monitoring torque value, first monitoring angle value, second monitoring torque value, and second monitoring angle value, the tightening torque and tightening angle of the workpiece are monitored in the bolt tightening condition, the data of the tightening torque and tightening angle are recorded, and the data are statistically analyzed.

[0012] Furthermore, the method for performing statistical analysis on the recorded tightening torque and tightening angle data includes: taking data of a preset number of samples multiple times, with the number of sample data increasing successively, and using the normal distribution principle to calculate successively to obtain the statistical analysis range values ​​of the first monitoring torque value, the first monitoring angle value, the second monitoring torque value, and the second monitoring angle value, and taking the middle value of the statistical analysis range value of the final number of times as the corrected first monitoring torque value, the first monitoring angle value, the second monitoring torque value, and the second monitoring angle value.

[0013] Furthermore, the method for monitoring the bolt tightening condition according to the corrected first monitoring torque value, first monitoring angle value, second monitoring torque value, and second monitoring angle value includes: when the bolt tightening angle reaches the first monitoring angle value α, if the torque exceeds the set torque value, the workpiece thread is defective, otherwise the workpiece is tightened normally; when the bolt tightening angle reaches the second monitoring angle value β, if the torque exceeds the set torque value, the workpiece is tightened and the thread is slipped, otherwise the workpiece is tightened normally. When the workpiece is tightened abnormally, the tightening equipment will automatically alarm and shut down.

[0014] A bolt tightening monitoring torque and angle calculation setting system designed based on the above bolt tightening monitoring torque and angle calculation setting method includes a monitoring value preset module and a monitoring value correction module;

[0015] The monitoring value preset module is used to set a first monitoring torque value according to the final tightening torque value, and set a first monitoring angle value according to the effective screwing length of the bolt and the thread specification; set a second monitoring torque value according to the final tightening torque value, and set a second monitoring angle value according to the thread specification;

[0016] The monitoring value correction module is used to perform data statistics on the tightening results of the workpiece according to the first monitoring torque value, the first monitoring angle value, the second monitoring torque value, and the second monitoring angle value, and repeatedly use the normal distribution principle to analyze and calculate the statistical data to obtain the corrected first monitoring torque value, the first monitoring angle value, the second monitoring torque value, and the second monitoring angle value, and monitor the bolt tightening condition according to the corrected first monitoring torque value, the first monitoring angle value, the second monitoring torque value, and the second monitoring angle value.

[0017] Beneficial effects of the present invention: Some of the existing bolt tightening processes do not adopt the monitoring of tightening torque and tightening angle during the tightening process, and cannot detect the quality defects of the workpiece in the tightening process early, terminate the tightening process in time, and perform repair and inspection; some of them already have the ability to monitor the tightening torque and tightening angle during the tightening process, but the monitoring values ​​set for angle monitoring and torque monitoring are unreasonable, resulting in the scrapping of the workpiece. In order to improve the qualified rate of product tightening, optimize the configuration of the tightening strategy, avoid repairs and waste caused by bolt tightening, the present invention accurately corrects the angle monitoring value and torque monitoring value through the normal distribution principle, optimizes the tightening strategy, and improves the qualified rate of product tightening. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is the moment and angle variation diagram of the present invention;

[0019] Figure 2 The abnormal tightening curve of the present invention Figure 1 ;

[0020] Figure 3 The abnormal tightening curve of the present invention Figure 2 ;

[0021] Figure 4 It is the abnormal monitoring torque value diagram of the present invention;

[0022] Figure 5 It is the abnormal monitoring angle value diagram of the present invention;

[0023] Figure 6 It is a bolt specification diagram of the present invention;

[0024] Figure 7 A schematic diagram of monitoring value setting of the present invention;

[0025] Figure 8 It is a structural schematic diagram of the present invention. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0027] Figures 1 to 5The horizontal axis is the tightening angle, and the vertical axis is the tightening torque. The final torque line and the final angle line required for the final tightening of the bolt are drawn from the horizontal axis and the vertical axis respectively, such as Figure 1 During the normal tightening process of the screw shown in the figure, the ideal curve of tightening torque and tightening angle should gradually approach the intersection of the final torque line and the final angle line, and stabilize at the intersection. The ideal curve of tightening torque and tightening angle rises slowly when the bolt starts to be tightened, accelerates in the middle and late stages, and gradually stabilizes when approaching the intersection of the final torque line and the final angle line.

[0028] If the tightening torque and tightening angle are not monitored during the bolt tightening process: Figure 2 As shown in the figure, when the tightening angle remains unchanged during the bolt tightening process and the initial tightening torque increases suddenly, it is impossible to monitor the abnormal rise of the tightening torque and tightening angle curve when the bolt starts to be tightened, resulting in thread defects, or Figure 3 As shown, when the final torque is too small during the bolt tightening process, it is impossible to monitor that the tightening torque and tightening angle curves are not stable at the intersection of the final torque line and the final angle line, resulting in bolt slippage and failure to tighten;

[0029] If the monitoring value is set unreasonable: Figure 4 As shown: the monitoring torque value is set too large, for example, the monitoring torque value is set close to the final torque value, resulting in the inability to intercept the abnormal increase in the initial tightening torque of the bolt, causing damage to the bolt; or Figure 5 As shown, when the monitoring angle is set too small, the tightening torque and tightening angle curves are not stabilized at the intersection of the final torque line and the final angle line, resulting in the inability to determine the tightening condition of the bolt and no monitoring effect.

[0030] Example 1

[0031] In order to solve the above problems, Figure 7 As shown, a method for calculating and setting a bolt tightening monitoring torque and angle comprises:

[0032] A first monitoring torque value is set according to the final tightening torque value, and a first monitoring angle value is set according to the effective screwing length of the bolt and the thread specification; a second monitoring torque value is set according to the final tightening torque value, and a second monitoring angle value is set according to the thread specification;

[0033] According to the first monitoring torque value, the first monitoring angle value, the second monitoring torque value and the second monitoring angle value, data statistics are performed on the tightening results of the workpiece, and the normal distribution principle is used multiple times to analyze and calculate the statistical data to obtain the corrected first monitoring torque value, the first monitoring angle value, the second monitoring torque value and the second monitoring angle value, and the bolt tightening condition is monitored according to the corrected first monitoring torque value, the first monitoring angle value, the second monitoring torque value and the second monitoring angle value.

[0034] In the above technical solution, the method for obtaining the first monitoring torque value and the first monitoring angle value includes: the first monitoring torque value is set to F1=T*(45%-50%), T is the final tightening torque value; the first monitoring angle value α=(M / m*360-360)°, M is the effective screwing length value of the bolt, and m is the thread specification, such as Figure 6 The final tightening torque value T is a known design value.

[0035] The first monitoring angle value is the angle that the bolt needs to rotate when the bolt is tightened to about half, and the second monitoring angle value is the angle that the bolt needs to rotate when the bolt is fully tightened.

[0036] The preset value of the first monitoring torque value is obtained based on experience to avoid tightening damage and workpiece scrapping caused by unreasonable torque setting. The calculation method of the first monitoring torque value α is based on past experience and data statistical summary.

[0037] In the above technical solution, the actual value of the first monitoring angle value α cannot be greater than the calculated value.

[0038] If the actual value of the first monitoring torque value α is greater than the calculated value, the bolt will be over-tightened and the workpiece will be scrapped.

[0039] In the above technical solution, the method for obtaining the second monitoring torque value and the second monitoring angle value includes: the second monitoring torque value is set to F2 = T*(95% to 100%); the second monitoring angle value β = (m*360 / 2)°, where m is the thread specification. The preset value of the second monitoring torque value is obtained based on experience to prevent the parts from being damaged and scrapped due to excessive torque. The calculation method of the second monitoring torque value β is based on previous experience and data statistical summary.

[0040] In the above technical solution, the actual value of the second monitoring angle value β cannot be less than the calculated value. If the actual value of the second monitoring angle value β is less than the calculated value, the tightening device will alarm and stop working when the workpiece is not completely tightened.

[0041] In the above technical solution, according to the set first monitoring torque value, first monitoring angle value, second monitoring torque value, and second monitoring angle value, the workpiece tightening torque and tightening angle are monitored in the bolt tightening condition, the tightening torque and tightening angle data are recorded, and the data are statistically analyzed. By statistically analyzing the workpiece tightening data under the preset first monitoring torque value, first monitoring angle value, second monitoring torque value, and second monitoring angle value, the preset monitoring torque value and monitoring angle value are corrected.

[0042] In the above technical scheme, the method for performing statistical analysis on the recorded tightening torque and tightening angle data includes: taking data of a preset number of samples multiple times, the number of sample data increases successively, and using the normal distribution principle to calculate successively to obtain the statistical analysis range values ​​of the first monitoring torque value, the first monitoring angle value, the second monitoring torque value, and the second monitoring angle value, and taking the middle value of the statistical analysis range value of the final number of times as the corrected first monitoring torque value, the first monitoring angle value, the second monitoring torque value, and the second monitoring angle value.

[0043] Normal distribution principle:

[0044] 1. Calculate the mean μ

[0045] μ=(a1+a2+...+an) / n, where a1, a2, ..., an are the sample data extracted, and n is the number of samples extracted;

[0046] 2. Calculate the variance σ2: σ2 = [(a1-μ)2+(a2-μ)2+...+(an-μ)2] / (n). The variance can measure the degree of dispersion of the data distribution, that is, the average of the squares of the deviations between the data and its mean;

[0047] 3. Calculate the standard deviation σ: σ = √σ2. The standard deviation is the square root of the variance, which directly reflects the degree of dispersion of the data points.

[0048] 4. Determine the 3σ range: The 3σ range is the interval centered on the mean and bounded by plus or minus 3 standard deviations, i.e. (μ-3σ,μ+3σ). According to the 3σ principle, this interval contains 99.73% of the data points.

[0049] Specific implementation method:

[0050] Step 1: First, take sample data of 100 workpieces, the sample data including the first monitoring torque value, the first monitoring angle value, the second monitoring torque value, and the second monitoring angle value of these 100 workpiece samples, and use the 3σ principle to calculate the mean and standard deviation of the first monitoring torque value, the first monitoring angle value, the second monitoring torque value, and the second monitoring angle value, and determine the 3σ range of the four monitoring values ​​respectively. At this time, the mean of the four monitoring values ​​is used as the new first monitoring torque value, the first monitoring angle value, the second monitoring torque value, and the second monitoring angle value. Run for a period of time and proceed to step 2.

[0051] Step 2: Take sample data of 500 workpieces, including the first monitoring torque value, the first monitoring angle value, the second monitoring torque value, and the second monitoring angle value of the 500 workpiece samples. The data in the sample data of 500 workpieces that exceeds the 3σ range corresponding to step 1 is abnormal data. After eliminating the abnormal data, based on the normal data, the mean and 3σ range of the first monitoring torque value, the first monitoring angle value, the second monitoring torque value, and the second monitoring angle value of the 500 workpieces are obtained, and the obtained mean is used as the new first monitoring torque value, the first monitoring angle value, the second monitoring torque value, and the second monitoring angle value. Run for a period of time and proceed to step 3.

[0052] Step 3: Take sample data of 1000 workpieces and repeat step 1, the sample data includes the first monitoring torque value, the first monitoring angle value, the second monitoring torque value, and the second monitoring angle value of the 1000 workpiece samples. The data whose sample data exceeds the 3σ range corresponding to step 2 in the 1000 workpiece samples is abnormal data. After eliminating the abnormal data, based on the normal data, the mean and 3σ range of the first monitoring torque value, the first monitoring angle value, the second monitoring torque value, and the second monitoring angle value of the 1000 workpiece samples are obtained, and the obtained mean value is used as the final correction to obtain the first monitoring torque value, the first monitoring angle value, the second monitoring torque value, and the second monitoring angle value with higher accuracy. When the first monitoring torque value, the first monitoring angle value, the second monitoring torque value, and the second monitoring angle value with higher accuracy are finally corrected and applied to production, when the workpiece data exceeds the 3σ range obtained in step 3, it is detected as abnormal bolt tightening.

[0053] The preset first monitoring torque value, first monitoring angle value, second monitoring torque value, and second monitoring angle value are values ​​with a large range and large errors obtained based on experience and calculation. The three sampling corrections are performed based on the 3σ principle to further refine the values ​​of the first monitoring torque value, the first monitoring angle value, the second monitoring torque value, and the second monitoring angle value. Generally, the corrected first monitoring torque value, the first monitoring angle value, the second monitoring torque value, and the second monitoring angle value can be determined by proceeding to step 2, but the monitoring value obtained through step 3 is more accurate, that is, the more samples there are, the more corrections there are, and the higher the accuracy of the monitoring value is. The number of corrections can be considered according to the specific situation, and the number of samples in each step can also be considered according to the specific situation.

[0054] In the above technical scheme, the method for monitoring the bolt tightening condition according to the corrected first monitoring torque value, the first monitoring angle value and the second monitoring torque value, and the second monitoring angle value includes: when the bolt tightening angle reaches the first monitoring angle value α, if the torque exceeds the set torque value, the workpiece thread is defective, otherwise the workpiece is tightened normally; when the bolt tightening angle reaches the second monitoring angle value β, if the torque exceeds the set torque value, the workpiece is tightened and the thread is slipped, otherwise the workpiece is tightened normally. When the workpiece is tightened abnormally, the tightening equipment will automatically alarm and shut down.

[0055] By monitoring the bolt tightening condition through the corrected first monitoring torque value, the first monitoring angle value, the second monitoring angle value, the workpiece defects can be discovered in time during the tightening process to avoid scrapping and rework caused by continuous tightening. At the same time, over-tightening of the workpiece to cause thread slippage can be avoided when the tightening of the workpiece is about to end.

[0056] Example 2

[0057] like Figure 8 As shown, a bolt tightening monitoring torque and angle calculation setting system designed based on the above-mentioned bolt tightening monitoring torque and angle calculation setting method includes a monitoring value preset module and a monitoring value correction module;

[0058] The monitoring value preset module is used to set a first monitoring torque value according to the final tightening torque value, and set a first monitoring angle value according to the effective screwing length of the bolt and the thread specification; set a second monitoring torque value according to the final tightening torque value, and set a second monitoring angle value according to the thread specification;

[0059] The monitoring value correction module is used to perform data statistics on the tightening results of the workpiece according to the first monitoring torque value, the first monitoring angle value, the second monitoring torque value, and the second monitoring angle value, and repeatedly use the normal distribution principle to analyze and calculate the statistical data to obtain the corrected first monitoring torque value, the first monitoring angle value, the second monitoring torque value, and the second monitoring angle value, and monitor the bolt tightening condition according to the corrected first monitoring torque value, the first monitoring angle value, the second monitoring torque value, and the second monitoring angle value.

[0060] Example 3

[0061] The present invention also includes a computer program product, including a computer program / instruction, which, when executed by a processor, implements the steps of the above-mentioned bolt tightening monitoring torque and angle calculation setting method.

[0062] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

Claims

1. A method for calculating and setting a bolt tightening monitoring torque and angle, characterized in that: It includes: The first monitoring torque value is set according to the final tightening torque value, and the first monitoring angle value is set according to the effective screwing length of the bolt and the thread specification; Set the second monitoring torque value according to the final tightening torque value, and set the second monitoring angle value according to the thread specification; According to the first monitoring torque value, the first monitoring angle value, the second monitoring torque value and the second monitoring angle value, data statistics are performed on the tightening results of the workpiece, and the normal distribution principle is used multiple times to analyze and calculate the statistical data to obtain the corrected first monitoring torque value, the first monitoring angle value, the second monitoring torque value and the second monitoring angle value, and the bolt tightening condition is monitored according to the corrected first monitoring torque value, the first monitoring angle value, the second monitoring torque value and the second monitoring angle value.

2. A method for calculating and setting a bolt tightening monitoring torque and angle according to claim 1, characterized in that: The method for obtaining the first monitoring torque value and the first monitoring angle value includes: the first monitoring torque value is set to F1=T*(45%~50%), T is the final tightening torque value; the first monitoring angle value α=(M / m*360-360)°, M is the effective screwing length value of the bolt, and m is the thread specification.

3. A method for calculating and setting a bolt tightening monitoring torque and angle according to claim 2, characterized in that: The actual value of the first monitoring angle value α cannot be greater than the calculated value.

4. The method for calculating and setting the bolt tightening monitoring torque and angle according to claim 1, characterized in that: The method for obtaining the second monitoring torque value and the second monitoring angle value includes: setting the second monitoring torque value to F2=T*(95%-100%); the second monitoring angle value β=(m*360 / 2)°, where m is the thread specification.

5. A method for calculating and setting a bolt tightening monitoring torque and angle according to claim 4, characterized in that: The actual value of the second monitoring angle value β cannot be less than the calculated value.

6. The method for calculating and setting the bolt tightening monitoring torque and angle according to claim 1, characterized in that: According to the set first monitoring torque value, first monitoring angle value, second monitoring torque value, and second monitoring angle value, the workpiece tightening torque and tightening angle are monitored in the bolt tightening condition, the tightening torque and tightening angle data are recorded, and the data are statistically analyzed and calculated.

7. The method for calculating and setting the bolt tightening monitoring torque and angle according to claim 1, characterized in that: The method for performing statistical analysis on the recorded tightening torque and tightening angle data includes: taking data of a preset number of samples multiple times, with the number of sample data increasing successively, and using the normal distribution principle to calculate successively to obtain the statistical analysis range values ​​of the first monitoring torque value, the first monitoring angle value, the second monitoring torque value, and the second monitoring angle value, and taking the middle value of the statistical analysis range value of the final number of times as the corrected first monitoring torque value, the first monitoring angle value, the second monitoring torque value, and the second monitoring angle value.

8. A method for calculating and setting a bolt tightening monitoring torque and angle according to claim 1 or 7, characterized in that: The method for monitoring the bolt tightening condition according to the corrected first monitoring torque value, the first monitoring angle value, the second monitoring torque value, and the second monitoring angle value includes: when the bolt tightening angle reaches the first monitoring angle value α, if the torque exceeds the set torque value, the workpiece thread is defective, otherwise the workpiece is tightened normally; when the bolt tightening angle reaches the second monitoring angle value β, if the torque exceeds the set torque value, the workpiece is tightened and the thread is slipped, otherwise the workpiece is tightened normally. When the workpiece is tightened abnormally, the tightening equipment will automatically alarm and shut down.

9. A system based on a bolt tightening monitoring torque and angle calculation and setting method according to any one of claims 1 to 8, comprising: The monitoring value preset module is used to set a first monitoring torque value according to the final tightening torque value, and to set a first monitoring angle value according to the effective screwing length of the bolt and the thread specification; Set the second monitoring torque value according to the final tightening torque value, and set the second monitoring angle value according to the thread specification; The monitoring value correction module is used to perform data statistics on the tightening results of the workpiece according to the first monitoring torque value, the first monitoring angle value, the second monitoring torque value, and the second monitoring angle value, and repeatedly use the normal distribution principle to analyze and calculate the statistical data to obtain the corrected first monitoring torque value, the first monitoring angle value, the second monitoring torque value, and the second monitoring angle value, and monitor the bolt tightening condition according to the corrected first monitoring torque value, the first monitoring angle value, the second monitoring torque value, and the second monitoring angle value.

10. A computer program product, comprising a computer program / instruction, which implements the steps of the method according to claim 1 when executed by a processor.

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