PLC-based eccentric rotary valve machining control method and system and storage medium

Abstract

The application relates to a PLC-based eccentric rotary valve machining control method and system and a storage medium, relates to the technical field of valve machining, and comprises the following steps: collecting a current grinding stage of a preset valve core and a preset valve body; searching for corresponding experience grinding speed in a preset stage grinding speed relationship according to the current grinding stage; performing trial grinding on the valve core and the valve body in response to the experience grinding speed, collecting a trial grinding pressure stroke curve, analyzing the trial grinding pressure stroke curve to generate a speed correction coefficient, correcting the experience grinding speed based on the speed correction coefficient to generate a corrected grinding speed, and performing matched grinding on the valve core and the valve body in response to the corrected grinding speed. The application has the effect of improving the precision of matched grinding of the valve body and the valve core.

Description

Technical Field

[0001] This application relates to the technical field of valve processing, and in particular to a PLC-based control method, system, and storage medium for the processing of eccentric rotary valves. Background Technology

[0002] Eccentric rotary valves, also known as cam flexure valves, are high-performance control valves that combine features of ball valves and butterfly valves. They are renowned for their excellent sealing performance, large flow capacity, and good regulating characteristics.

[0003] In related technologies, in order to meet the sealing requirements of eccentric rotary valves, the valve core and valve body of the eccentric rotary valve are usually paired and ground. The valve body is fixed on a fixture, so that the valve core and valve body are pressed together with a certain pressure. Then, an empirical speed is selected to control the valve core to rotate along the actual rotation direction, so that the valve core and valve body are paired and ground, and the sealing surface fit is gradually improved.

[0004] Regarding the aforementioned technologies, the empirical speed is selected to control the valve core rotation for mating and grinding with the valve body. However, due to the individual differences between the valve core and the valve body, it cannot be guaranteed that the empirical speed is suitable for mating and grinding the valve core and the valve body. This may cause vibration in the valve body and valve core at the empirical speed, resulting in low mating and grinding accuracy of the valve body and valve core. There is still room for improvement. Summary of the Invention

[0005] To improve the precision of the mating grinding of the valve body and valve core, this application provides a PLC-based eccentric rotary valve processing control method, system, and storage medium.

[0006] Firstly, this application provides a PLC-based method for controlling the machining of eccentric rotary valves, employing the following technical solution:

[0007] A PLC-based control method for the machining of eccentric rotary valves includes:

[0008] Collect the current grinding stage of the preset valve core and preset valve body;

[0009] Based on the current grinding stage, find the corresponding empirical grinding speed from the preset stage grinding speed relationship;

[0010] The valve core and valve body were tested using an empirical grinding speed, and the test grinding pressure-stroke curves were collected.

[0011] The pressure-stroke curve of the trial grinding was analyzed to generate a speed correction coefficient;

[0012] The empirical grinding speed is corrected based on the speed correction coefficient to generate a corrected grinding speed;

[0013] In response to adjust the grinding speed for mating grinding of the valve core and valve body.

[0014] Optionally, the step of analyzing the test grinding pressure-stroke curve to generate a speed correction factor includes:

[0015] Based on the current grinding stage, find the corresponding standard pressure-stroke curve in the preset stage pressure-stroke relationship;

[0016] The pressure stroke curve of the trial grinding is denoised based on the standard pressure stroke curve to generate an accurate pressure stroke curve;

[0017] The standard pressure stroke curve and the precise pressure stroke curve are sampled synchronously according to the preset sampling sliding window to generate the sampling standard pressure and the sampling test grinding pressure.

[0018] Calculate the difference between the sampling standard pressure and the sampling test grinding pressure to generate the test grinding pressure difference value;

[0019] Determine whether the difference in test grinding pressure is greater than the preset reference pressure difference value;

[0020] If it is not greater than, then the preset uncorrected coefficient is defined as the speed correction coefficient;

[0021] If the difference is greater than the standard sampling pressure and the sampling test grinding pressure, then the difference between the standard sampling pressure and the test grinding pressure is quantified to generate a speed correction coefficient.

[0022] Optionally, the step of denoising the test grinding pressure-stroke curve based on the standard pressure-stroke curve to generate an accurate pressure-stroke curve includes:

[0023] Calculate the average pressure of the standard pressure stroke curve to generate a noise-reduced standard pressure;

[0024] The test grinding pressure stroke curve is sampled synchronously according to the preset sampling sliding window to generate the pressure to be tested and the corresponding stroke to be tested;

[0025] Determine whether the pressure to be tested is consistent with the noise reduction standard pressure;

[0026] If so, the pressure to be tested will be determined as the noise-reduced pressure;

[0027] If not, then the pressure to be tested is denoised according to the denoising standard pressure to generate a denoised pressure;

[0028] A precise pressure-stroke curve is redrawn based on the noise-reduced pressure and the stroke to be detected.

[0029] Optionally, the step of reducing the noise of the pressure to be tested according to the noise reduction standard pressure to generate the noise-reduced pressure includes:

[0030] The test pressure for the same stroke is obtained by sampling from the test grinding pressure-stroke curve based on the stroke to be tested.

[0031] Determine whether the pressure detected in the same stroke is consistent with the pressure to be detected;

[0032] If they match, the valve core and valve body are ground according to the preset noise reduction grinding speed to determine the noise reduction pressure.

[0033] If they are inconsistent, the pressure to be tested corresponding to the stroke to be tested is replaced with the noise-reduced standard pressure to generate the noise-reduced pressure.

[0034] Optionally, the step of grinding the valve core and valve body according to a preset noise-reducing grinding speed to determine the noise-reduced pressure includes:

[0035] The valve core and valve body are ground according to the preset noise reduction grinding speed, and the variable speed pressure stroke curve is collected.

[0036] The variable speed stroke detection pressure is obtained by sampling from the variable speed pressure stroke curve based on the stroke to be detected.

[0037] Determine whether the pressure detected during the shift stroke is consistent with the pressure to be detected;

[0038] If they match, the pressure to be tested corresponding to the stroke to be tested is replaced with the noise-reduced standard pressure to generate the noise-reduced pressure;

[0039] If there is a discrepancy, the pressure to be tested will be determined as the noise-reduced pressure.

[0040] Optionally, the step of quantifying the difference between the sampling standard pressure and the sampling test grinding pressure to generate the rotational speed correction factor includes:

[0041] Calculate the mean of the sampled standard pressures to generate the standard pressure mean;

[0042] Calculate the mean value of the sampled grinding pressure to generate the mean value of the grinding pressure;

[0043] Calculate the quotient of the average standard pressure and the average test grinding pressure to generate the first correction factor;

[0044] The first correction factor is adjusted based on the fluctuation of the sampling standard pressure and the sampling test grinding pressure to generate the rotational speed correction factor.

[0045] Optionally, the step of correcting the first correction coefficient based on the fluctuation of the sampling standard pressure and the sampling test grinding pressure to generate the rotational speed correction coefficient includes:

[0046] Calculate the standard deviation of the sampled standard pressure to generate standard pressure fluctuation values;

[0047] Calculate the standard deviation of the sampled grinding pressure to generate the grinding pressure fluctuation value;

[0048] Calculate the quotient of the standard pressure fluctuation value and the test grinding pressure fluctuation value to generate a second correction factor;

[0049] Collect defect mutation stress values;

[0050] The product of the first correction factor and the second correction factor is corrected based on the defect mutation pressure value to generate the speed correction factor.

[0051] Optionally, the step of correcting the product of the first correction factor and the second correction factor based on the defect mutation pressure value to generate the speed correction factor includes:

[0052] Calculate the quotient of the defect mutation pressure value and the sampling standard pressure to generate the defect influence coefficient;

[0053] Calculate the difference between the preset no-impact coefficient and the defect impact coefficient to generate the defect impact correction coefficient;

[0054] Calculate the product of the first correction factor, the second correction factor, and the defect influence correction factor to generate the speed correction factor.

[0055] Secondly, this application provides a PLC-based eccentric rotary valve processing control system, which adopts the following technical solution:

[0056] A PLC-based eccentric rotary valve machining control system includes:

[0057] The data acquisition module is used to acquire data on the current grinding stage and the pressure-stroke curve of the trial grinding process.

[0058] A memory for storing the program of the PLC-based eccentric rotary valve machining control method as described in any of the above items;

[0059] The processor and the program in the memory can be loaded and executed by the processor to implement the PLC-based eccentric rotary valve machining control method as described in any of the above.

[0060] Thirdly, this application provides a computer storage medium capable of storing corresponding programs, which facilitates improving the precision of the mating grinding of the valve body and valve core, and adopts the following technical solution:

[0061] A computer-readable storage medium storing a computer program that can be loaded by a processor and executed by the PLC-based eccentric rotary valve machining control method described above.

[0062] In summary, this application includes at least one of the following beneficial technical effects:

[0063] 1. By performing trial grinding on the valve core and valve body, the trial grinding pressure-stroke curve is collected. After analyzing the trial grinding pressure-stroke curve, the speed correction coefficient is obtained. The empirical grinding speed is corrected according to the speed correction coefficient to obtain the corrected grinding speed. The valve core and valve body are then paired and ground at the corrected grinding speed to ensure the stability of the valve core and valve body during the grinding process, thereby improving the accuracy of the paired grinding of the valve body and valve core.

[0064] 2. By reducing the noise of the test grinding pressure stroke curve using the standard pressure stroke curve, an accurate pressure stroke curve that eliminates the influence of valve core and valve body defects is obtained. Then, the sampling standard pressure and the sampling test grinding pressure are obtained by sampling from the standard pressure stroke curve and the accurate pressure stroke curve. The difference between the sampling standard pressure and the sampling test grinding pressure is quantified to obtain the speed correction coefficient, thereby improving the accuracy of the speed correction coefficient.

[0065] 3. By evaluating the stability of the sampling test grinding pressure and the influence coefficient of defect residue, the rotation speed correction coefficient is determined, thereby improving the accuracy of the rotation speed correction coefficient. Attached Figure Description

[0066] Figure 1 This is a flowchart of the PLC-based eccentric rotary valve processing control method in the embodiments of this application.

[0067] Figure 2 This is a flowchart of the steps in this application embodiment to analyze the test grinding pressure stroke curve to generate a rotational speed correction coefficient.

[0068] Figure 3 This is a flowchart of the steps in this application embodiment to reduce the noise of the test grinding pressure stroke curve based on the standard pressure stroke curve in order to generate an accurate pressure stroke curve.

[0069] Figure 4 This is a flowchart of the steps in this application embodiment to reduce the noise of the pressure to be tested according to the noise reduction standard pressure in order to generate a noise-reduced pressure.

[0070] Figure 5 This is a flowchart of the steps in this application embodiment to grind the valve core and valve body according to a preset noise reduction grinding speed in order to determine the noise reduction pressure.

[0071] Figure 6 This is a flowchart of the steps in this application embodiment to quantify the difference between the sampling standard pressure and the sampling test grinding pressure in order to generate a rotational speed correction coefficient.

[0072] Figure 7 This is a flowchart of the steps in this application embodiment to correct the first correction coefficient based on the fluctuation of the sampling standard pressure and the sampling test grinding pressure to generate the rotational speed correction coefficient.

[0073] Figure 8 This is a flowchart of the steps in this application embodiment to correct the product of the first correction coefficient and the second correction coefficient based on the defect mutation pressure value to generate the speed correction coefficient. Detailed Implementation

[0074] To make the purpose, technical solution, and advantages of this application clearer, the following description is provided in conjunction with the appendix. Figures 1 to 8 The present application will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the application.

[0075] Reference Figure 1 This application discloses a PLC-based method for controlling the machining of eccentric rotary valves, including the following steps:

[0076] Step S100: Collect the current grinding stage of the preset valve core and preset valve body.

[0077] The current grinding stage refers to the stage where the valve core and valve body are paired and ground. It usually includes a rough grinding stage, a fine grinding stage, and a polishing stage. The rough grinding stage has the highest rotation speed and is used to remove unevenness and defects on the valve core and valve body. The fine grinding stage has a lower rotation speed than the rough grinding stage and is used to improve the fit between the valve core and valve body. The polishing stage has a lower rotation speed than the fine grinding stage and is used to improve the smoothness of the sealing surfaces of the valve core and valve body. The current grinding stage can be entered by the operator in the processing terminal.

[0078] By collecting data on the current grinding stage of the valve core and valve body, the empirical grinding speed range for pairing grinding of the valve core and valve body can be determined, providing data support for further determining the optimal grinding speed.

[0079] Step S101: Find the corresponding empirical grinding speed in the preset stage grinding speed relationship according to the current grinding stage.

[0080] Among them, the relationship between the grinding speed of the stages refers to the correspondence between different paired grinding stages and the grinding speed. The empirical speed of the coarse grinding stage is the highest, taking 12 revolutions per minute as an example in this embodiment. The empirical speed of the fine grinding stage is the second highest, taking 8 revolutions per minute as an example in this embodiment. The empirical speed of the polishing stage is the lowest, taking 4 revolutions per minute as an example in this embodiment. The operator forms a mapping table by matching the different paired grinding stages with the empirical speed.

[0081] The empirical grinding speed refers to the empirical pairing grinding speed at the current stage. It is obtained by the processing terminal by looking up the corresponding mapping table of grinding speed relationships at the current grinding stage. By determining the empirical grinding speed, data support is provided for subsequent trial grinding of the valve core and valve body, thereby determining whether the pairing grinding of the valve core and valve body is stable at this speed.

[0082] Step S102: In response to the empirical grinding speed, perform trial grinding on the valve core and valve body, and collect the trial grinding pressure-stroke curve.

[0083] After determining the empirical grinding speed, the operator fixes the valve body on the fixture, fixes the valve core on the rotating shaft of the drive motor, and applies a certain pressure to the valve core and valve body using the pneumatic device. The processing terminal controls the drive motor to drive the valve core to rotate in the working direction at the empirical grinding speed, thereby performing a trial grinding of the valve core and valve body. The specific trial grinding time is taken as 3 minutes, and the trial grinding pressure-stroke curve is collected to provide data support for subsequent analysis on whether the paired grinding of the valve core and valve body at the empirical grinding speed is stable.

[0084] The test grinding pressure-stroke curve refers to the curve showing the change in pressure between the valve core and valve body during the test grinding process. The pressure between the valve core and valve body is detected by a pressure sensor installed on the valve core drive shaft, and the rotation stroke of the valve core is recorded by an angle encoder. After one revolution, the stroke is recalculated. Thus, the test grinding pressure-stroke curve is plotted with the stroke as the abscissa and the pressure as the ordinate. This provides an analytical object for subsequent analysis of whether the empirical grinding speed is stable for paired grinding of the valve core and valve body.

[0085] Step S103: Analyze the pressure-stroke curve of the trial grinding to generate a speed correction coefficient.

[0086] The speed correction coefficient refers to the time required to correct the empirical grinding speed. It is obtained after analyzing the test grinding pressure-stroke curve. For example, if the pressure on the test grinding pressure-stroke curve is lower than the pressure on the standard curve, it indicates that the speed is too fast, causing intermittent disengagement between the valve core and the valve body. Therefore, the speed needs to be reduced, and the speed correction coefficient is less than 1. When the pressure on the test grinding pressure-stroke curve is within the error range of the standard curve, it indicates that the speed is suitable for pairing grinding, and therefore no speed adjustment is needed. The speed correction coefficient is 1. When the pressure on the test grinding pressure-stroke curve is higher than the pressure on the standard curve, it indicates that the speed is too slow, causing excessive friction between the valve core and the valve body. Therefore, the speed needs to be increased, and the speed correction coefficient is greater than 1. For specific analysis methods, refer to [reference needed]. Figure 2 The steps.

[0087] By analyzing the pressure-stroke curve of the trial grinding, the rotational speed correction coefficient is obtained, providing data support for subsequent correction of the empirical grinding speed.

[0088] Step S104: Correct the empirical grinding speed based on the speed correction coefficient to generate a corrected grinding speed.

[0089] Among them, the corrected grinding speed refers to the optimal grinding speed in the current pairing grinding stage. It is obtained by multiplying the empirical grinding speed and the speed correction coefficient calculated by the processing terminal. By using the speed correction coefficient to correct the empirical grinding speed, the accuracy of the pairing grinding of the valve core and valve body meets the accuracy requirements.

[0090] Step S105: In response to adjusting the grinding speed, the valve core and valve body are mated and ground.

[0091] In this process, after determining the corrected grinding speed, the processing terminal controls the drive motor to drive the valve core to rotate along the working direction at the corrected grinding speed, so that the valve core and valve body can be paired and ground in a stable state, thereby improving the accuracy of the paired grinding of the valve core and valve body.

[0092] Reference Figure 2 The steps for analyzing the pressure-stroke curve of the trial grinding process to generate the rotational speed correction coefficient include:

[0093] Step S200: Find the corresponding standard pressure-stroke curve in the preset stage pressure-stroke relationship according to the current grinding stage.

[0094] Among them, the stage pressure stroke relationship refers to the correspondence between different paired grinding stages and pressure stroke curves. Operators select qualified valve cores and valve bodies of the same model and material, perform paired grinding at an experienced grinding speed, use pressure sensors to collect the pressure between the two, and plot the pressure stroke curves after corresponding with the strokes. Then, a mapping table is formed by matching the paired grinding stages with the pressure stroke curves one by one.

[0095] The standard pressure-stroke curve refers to the pressure-stroke curve that meets the grinding accuracy requirements when grinding at the experienced grinding speed in the current grinding stage. It is obtained by the processing terminal by looking up the corresponding mapping table of stage pressure-stroke relationship in the current grinding stage. By determining the standard pressure-stroke curve, the pressure change that meets the grinding accuracy requirements can be determined. This provides data support for subsequent comparison with the test grinding pressure-stroke curve to analyze and calculate the speed correction coefficient.

[0096] Step S201: Denoise the test grinding pressure stroke curve based on the standard pressure stroke curve to generate an accurate pressure stroke curve.

[0097] Among them, the precise pressure stroke curve refers to the pressure stroke curve that retains only the pressure fluctuations caused by the rotation speed. It is obtained by the processing terminal after noise reduction of the test grinding pressure stroke curve based on the standard pressure stroke curve. The specific method is described in [reference needed]. Figure 3 The steps involve determining a precise pressure stroke curve, thereby retaining only the pressure fluctuation caused by the rotational speed. When subsequently analyzing and calculating the rotational speed correction coefficient, only the pressure fluctuation caused by the rotational speed is compared with the standard pressure fluctuation, thus improving the accuracy of the calculated rotational speed correction coefficient.

[0098] Step S202: Simultaneously sample the standard pressure stroke curve and the precise pressure stroke curve according to the preset sampling sliding window to generate the sampling standard pressure and the sampling test grinding pressure.

[0099] The sampling sliding window refers to a sliding window that samples the standard pressure stroke curve and the precise pressure stroke curve. In this embodiment, a sliding window with a width of 1 degree is used as an example, so that the pressure value corresponding to 1 degree stroke is sampled each time.

[0100] The sampling standard pressure refers to the pressure value corresponding to one stroke in the standard pressure stroke curve. It is obtained by the processing terminal sampling sequentially along the horizontal axis of the standard pressure stroke curve according to the sampling sliding window, and identifying the vertical axis corresponding to each horizontal axis.

[0101] The sampling test grinding pressure refers to the pressure value corresponding to the same stroke in the precision pressure stroke curve. It is obtained by the processing terminal sampling sequentially along the horizontal axis of the precision pressure stroke curve according to the sampling sliding window, and identifying the vertical axis corresponding to each horizontal axis.

[0102] By determining the standard sampling pressure and the sampling test grinding pressure, the difference between the two is analyzed. On the one hand, it is determined whether the grinding of the valve core and valve body at the empirical grinding speed is stable. On the other hand, when it is determined that the grinding of the valve core and valve body is unstable, the speed correction coefficient is calculated based on the analysis of the two, and the empirical grinding speed is corrected in time. Thus, the valve core and valve body are paired and ground at the corrected speed to ensure the accuracy of the paired grinding of the valve core and valve body.

[0103] Step S203: Calculate the difference between the sampling standard pressure and the sampling test grinding pressure to generate the test grinding pressure difference value.

[0104] Among them, the test grinding pressure difference value refers to the index of the grinding stability between the valve core and the valve body. The larger the test grinding pressure difference value, the worse the grinding stability between the valve core and the valve body. Conversely, the smaller the test grinding pressure difference value, the better the grinding stability between the valve core and the valve body. The absolute value of the difference between the sampling standard pressure and the sampling test grinding pressure is calculated by the processing terminal.

[0105] Step S204: Determine whether the difference in test grinding pressure is greater than the preset reference pressure difference value.

[0106] The reference pressure difference value refers to the lowest pressure difference value that indicates good grinding stability between the valve core and the valve body. The specific value is determined by the operator based on the actual situation.

[0107] By processing the terminal to determine whether the difference in test grinding pressure is greater than the difference in reference pressure, it is possible to determine whether pairing grinding of valve core and valve body with empirical grinding speed is stable.

[0108] Step S2041: If it is not greater than, then the preset uncorrected coefficient is defined as the speed correction coefficient.

[0109] If the processing terminal determines that the difference in test grinding pressure is not greater than the difference in reference pressure, it indicates that the stability of pairing grinding of valve core and valve body with empirical grinding speed is good, and the accuracy of pairing grinding of valve core and valve body is high. Therefore, there is no need to correct the empirical grinding speed, so the no-correction coefficient is defined as the speed correction coefficient.

[0110] The uncorrected factor is a factor that does not correct for the empirical grinding speed, i.e., it is 1.

[0111] Step S2042: If it is greater than, then quantify the difference between the sampling standard pressure and the sampling test grinding pressure to generate a rotation speed correction coefficient.

[0112] If the processing terminal determines that the difference in test grinding pressure is greater than the difference in reference pressure, it indicates that the stability of pairing grinding of the valve core and valve body using the empirical grinding speed is poor, and the empirical grinding speed needs to be corrected. Therefore, the difference between the sampling standard pressure and the sampled test grinding pressure is quantified to obtain the speed correction coefficient. The specific method is described in [reference needed]. Figure 6 The steps.

[0113] Reference Figure 3 The steps for denoising the test grinding pressure stroke curve based on the standard pressure stroke curve to generate an accurate pressure stroke curve include:

[0114] Step S300: Calculate the average pressure of the standard pressure stroke curve to generate a noise-reduced standard pressure.

[0115] Among them, the noise reduction standard pressure refers to the first indicator for determining whether the pressure value corresponding to the test grinding pressure stroke curve needs to be noise-reduced. It is obtained by the processing terminal calculating the average value of all pressures in the standard pressure stroke curve. By determining the noise reduction standard pressure, data support is provided for subsequent noise reduction of the test grinding pressure stroke curve.

[0116] Step S301: The test grinding pressure stroke curve is sampled synchronously according to the preset sampling sliding window to generate the pressure to be tested and the corresponding stroke to be tested.

[0117] Among them, the pressure to be tested refers to the pressure in the test grinding pressure stroke curve that is waiting for noise reduction, and the stroke to be tested refers to the stroke corresponding to the pressure to be tested. It is obtained by the processing terminal by sliding the sampling window along the horizontal axis of the test grinding pressure stroke curve. By determining the pressure to be tested and the corresponding stroke to be tested, it is ensured that the test grinding pressure stroke curve can be comprehensively noise-reduced.

[0118] The sampling sliding window in this step is the same as the sampling sliding window in step S202, and will not be described again here.

[0119] Step S302: Determine whether the pressure to be tested is consistent with the noise reduction standard pressure.

[0120] Specifically, the processing terminal determines whether the pressure to be tested is consistent with the noise reduction standard pressure, thereby determining whether the pressure to be tested needs to be noise-reduced.

[0121] Step S3021: If yes, then the pressure to be detected is determined as the noise-reduced pressure.

[0122] If the processing terminal determines that the pressure to be detected is consistent with the noise reduction standard pressure, it indicates that the pressure to be detected is not unstable due to the rotation speed. Therefore, it is not necessary to reduce the noise of the pressure to be detected, thus determining the pressure to be detected as the noise-reduced pressure, providing data support for the subsequent redrawing of the accurate pressure stroke curve.

[0123] The noise-reduced pressure refers to the pressure after noise reduction in the test grinding pressure stroke curve. In this step, the noise-reduced pressure is the pressure to be tested itself.

[0124] Step S3022: If not, then reduce the noise of the pressure to be tested according to the noise reduction standard pressure to generate the noise-reduced pressure.

[0125] If the processing terminal determines that the pressure to be detected is inconsistent with the noise reduction standard pressure, it indicates that the pressure to be detected may be unstable due to the rotation speed. Therefore, the pressure to be detected is denoised according to the noise reduction standard pressure to generate the denoised pressure, which provides data support for redrawing the accurate pressure stroke curve.

[0126] The noise-reduced pressure in this step is the same as the noise-reduced pressure in step S3021. The difference is that the noise-reduced pressure in this step is obtained by the processing terminal after reducing the noise of the pressure to be detected according to the noise reduction standard pressure. For the specific method, please refer to [link / reference]. Figure 4 The steps.

[0127] Step S303: Redraw and generate an accurate pressure-stroke curve based on the noise-reduced pressure and the stroke to be detected.

[0128] In this step, the precise pressure stroke curve is consistent with the precise pressure stroke curve in step S201. The processing terminal uses the noise-reduced pressure as the vertical axis and the shape to be detected as the horizontal axis to input into the plotting software, thereby generating the precise pressure curve.

[0129] Reference Figure 4 The steps for reducing the noise of the pressure to be tested according to the noise reduction standard pressure to generate the noise-reduced pressure include:

[0130] Step S400: Based on the stroke to be tested, sample the same stroke test pressure from the test grinding pressure stroke curve.

[0131] Among them, the same stroke detection pressure refers to the pressure corresponding to the number of revolutions of the test stroke in the test grinding pressure stroke curve. For example, the test grinding pressure stroke curve includes the pressure and stroke of the valve core rotating n revolutions. The same stroke detection pressure is the pressure corresponding to the same test stroke in the n revolutions of pressure stroke. By determining the same stroke detection pressure, data support is provided for subsequent analysis of whether the pressure fluctuation of the stroke is caused by the rotation speed or defects in the valve core and valve body.

[0132] Step S401: Determine whether the pressure detected in the same stroke is consistent with the pressure to be detected.

[0133] Specifically, by processing the terminal to determine whether the pressure detected during the same stroke is consistent with the pressure to be detected, it can be determined whether the pressure change pattern is consistent in each revolution of the valve core and valve body grinding, thereby further determining whether the pressure change during the stroke is caused by the rotation speed or defects in the valve core and valve body.

[0134] Step S4011: If consistent, grind the valve core and valve body according to the preset noise reduction grinding speed to determine the noise reduction pressure.

[0135] If the processing terminal determines that the pressure detected during the same stroke is consistent with the pressure to be detected, it indicates that the pressure change pattern corresponding to that stroke is consistent for each revolution of the valve core and valve body during grinding. This may be due to changes in rotation speed or defects in the valve body. Therefore, the valve body and valve core are ground according to the noise reduction grinding speed to further analyze the cause of the pressure fluctuation and determine the noise-reduced pressure. Specific methods are described in [reference needed]. Figure 5 The steps.

[0136] Noise reduction grinding speed refers to the grinding speed of the valve body and valve core when the rotation speed cannot be determined or when pressure fluctuations are caused by defects in the valve body and valve core. The specific value is determined by the operator based on the actual situation. The noise reduction grinding speed is inconsistent with the experience grinding speed. If the pressure fluctuation at the stroke is caused by the rotation speed, the pressure fluctuation at that stroke will also change after the rotation speed is changed. However, if the pressure fluctuation at the stroke is caused by defects in the valve body and valve core, the pressure fluctuation at that stroke will not change even if the rotation speed is changed.

[0137] Step S4012: If they are inconsistent, replace the pressure to be tested corresponding to the stroke to be tested with the noise-reduced standard pressure to generate the noise-reduced pressure.

[0138] If the processing terminal determines that the pressure detected during the same stroke is inconsistent with the pressure to be detected, it indicates that the pressure fluctuation corresponding to that stroke is not caused by the rotational speed. Therefore, the pressure to be detected corresponding to the stroke to be detected needs to be replaced with the noise-reduced standard pressure to generate the noise-reduced pressure, so that the pressure fluctuation not caused by the rotational speed will not affect the rotational speed correction coefficient.

[0139] Reference Figure 5 The steps for grinding the valve core and valve body according to the preset noise reduction grinding speed to determine the noise reduction pressure include:

[0140] Step S500: Grind the valve core and valve body according to the preset noise reduction grinding speed, and collect the variable speed pressure stroke curve.

[0141] When the pressure detected during the same stroke is the same as the pressure to be detected, it is necessary to further analyze the cause of the pressure fluctuation. Therefore, the drive motor is controlled to rotate the valve core at a noise-reducing grinding speed to grind the valve core and valve body for a short time, and the variable speed pressure stroke curve is collected to provide data support for subsequent analysis of whether the pressure fluctuation at the same stroke changes.

[0142] The variable speed pressure stroke curve refers to the curve showing the change in pressure between the valve core and valve body during the grinding process after speed change, as the rotation stroke changes. The pressure between the valve core and valve body is detected by a pressure sensor installed on the valve core drive shaft, and the rotation stroke of the valve core is recorded by an angle encoder. After one revolution, the stroke is recalculated, and thus the variable speed pressure stroke curve is plotted with the stroke as the horizontal axis and the pressure as the vertical axis.

[0143] Step S501: Obtain the variable speed stroke detection pressure by sampling from the variable speed pressure stroke curve based on the stroke to be detected.

[0144] Among them, the speed change stroke detection pressure refers to the pressure corresponding to the stroke to be detected in the speed change pressure stroke curve. It is obtained by the processing terminal by identifying the corresponding pressure in the speed change pressure stroke curve according to the stroke to be detected. By determining the speed change stroke detection pressure, data support is provided for subsequent analysis of whether the pressure changes after the speed changes.

[0145] Step S502: Determine whether the pressure detected by the speed change stroke is consistent with the pressure to be detected.

[0146] Specifically, the processing terminal determines whether the pressure detected during the speed change stroke is consistent with the pressure to be detected, thereby determining whether the pressure fluctuation at the same stroke changes after the grinding speed changes.

[0147] Step S5021: If they match, replace the pressure to be tested corresponding to the stroke to be tested with the noise-reduced standard pressure to generate the noise-reduced pressure.

[0148] If the processing terminal determines that the pressure detected during the speed change stroke is consistent with the pressure to be detected, it indicates that the pressure at the same stroke did not change after the grinding speed changed. Therefore, it can be determined that the reason for the difference between the pressure at this stroke and the standard pressure is that there is a defect in the valve body or valve core. The pressure at this stroke should not affect the analysis speed correction coefficient. Therefore, all the pressures to be detected corresponding to the stroke to be detected are replaced with the noise-reduced standard pressure, thereby generating the noise-reduced pressure.

[0149] Step S5022: If there is no consistency, the pressure to be tested is determined to be the noise-reduced pressure.

[0150] If the processing terminal determines that the pressure detected during the speed change stroke is inconsistent with the pressure to be detected, it indicates that the pressure at the same stroke changes after the grinding speed changes. Therefore, the large difference between the pressure at this stroke and the standard pressure is due to the speed. Thus, the pressure to be detected is determined as the noise-reduced pressure, and the influence of the pressure to be detected in the analysis of the speed correction coefficient is maintained.

[0151] Reference Figure 6 The steps for quantifying the difference between the standard sampling pressure and the sampling test grinding pressure to generate a rotational speed correction coefficient include:

[0152] Step S600: Calculate the mean of the sampled standard pressures to generate the standard pressure mean.

[0153] The average standard pressure is an indicator used to judge whether the test grinding pressure is stable. It is obtained by calculating the average of the sampled standard pressures from the processing terminal. When the test grinding pressure is greater than the average standard pressure, it indicates that the rotation speed is too slow, resulting in excessive friction between the valve core and the valve body. When the test grinding pressure is less than the average standard pressure, it indicates that the rotation speed is too fast, resulting in intermittent separation between the valve core and the valve body.

[0154] Step S601: Calculate the average value of the sampled grinding pressure to generate the average value of the grinding pressure.

[0155] The average test grinding pressure refers to the data used to evaluate the grinding stability of the valve core and valve body. It is obtained by the processing terminal by calculating the average value of the sampled test grinding pressure. When the average test grinding pressure is greater than the average standard pressure, it indicates that the rotation speed is too slow, resulting in excessive friction between the valve core and valve body. When the average test grinding pressure is less than the average standard pressure, it indicates that the rotation speed is too fast, resulting in intermittent separation between the valve core and valve body.

[0156] Step S602: Calculate the quotient of the average standard pressure and the average test grinding pressure to generate the first correction factor.

[0157] The first correction factor refers to the correction factor for the rotational speed based on the difference in pressure amplitude. It is obtained by calculating the quotient of the average standard pressure and the average test grinding pressure at the processing terminal. When the average standard pressure is greater than the average test grinding pressure, the first correction factor is greater than 1, and the correction direction for the rotational speed is to increase the rotational speed. When the average standard pressure is less than the average test grinding pressure, the first correction factor is less than 1, and the correction direction for the rotational speed is to decrease the rotational speed.

[0158] Step S603: Correct the first correction coefficient according to the fluctuation of the sampling standard pressure and the sampling test grinding pressure to generate the rotation speed correction coefficient.

[0159] In this step, the rotational speed correction coefficient is the same as that in step S2042. The processing terminal first quantifies the fluctuation of the sampling standard pressure and the sampling test grinding pressure, thereby converting the fluctuation into a coefficient. Then, the coefficient is used to correct the first correction coefficient to obtain the rotational speed correction coefficient. The specific method is described in [reference needed]. Figure 7 The steps.

[0160] Reference Figure 7 The steps for generating the rotational speed correction coefficient by correcting the first correction coefficient based on the fluctuation of the sampling standard pressure and the sampling test grinding pressure include:

[0161] Step S700: Calculate the standard deviation of the sampled standard pressure to generate the standard pressure fluctuation value.

[0162] The standard pressure fluctuation value refers to the degree of fluctuation of the sampled standard pressure, which is obtained by calculating the standard deviation of the sampled standard pressure by the processing terminal. The standard pressure fluctuation value is an indicator for judging the stability of the fluctuation of the grinding pressure amplitude. If the pressure fluctuation value of the sampled test grinding pressure is greater than the standard pressure fluctuation value, it indicates that the rotation speed is too fast, resulting in excessive pressure fluctuation. If the pressure fluctuation value of the sampled test grinding pressure is less than the standard pressure fluctuation value, it indicates that the rotation speed is too slow, resulting in insufficient pressure fluctuation.

[0163] Step S701: Calculate the standard deviation of the sampled grinding pressure to generate the grinding pressure fluctuation value.

[0164] Among them, the test grinding pressure fluctuation value refers to the degree of fluctuation of the sampled test grinding pressure, which is obtained by the processing terminal calculating the standard deviation of the sampled test grinding pressure. The larger the test grinding pressure fluctuation value, the greater the fluctuation of the sampled test grinding pressure.

[0165] Step S702: Calculate the quotient of the standard pressure fluctuation value and the test grinding pressure fluctuation value to generate a second correction coefficient.

[0166] The second correction coefficient is a coefficient used to correct the rotation speed based on the degree of pressure fluctuation. It is obtained by calculating the quotient of the standard pressure fluctuation value and the test grinding pressure fluctuation value at the processing terminal. When the second correction coefficient is greater than 1, it indicates that the test grinding pressure fluctuation value is relatively mild and the rotation speed needs to be increased. When the second correction coefficient is less than 1, it indicates that the test grinding pressure fluctuation value is too severe and the rotation speed needs to be reduced.

[0167] Step S703: Collect defect mutation stress values.

[0168] Among them, the defect mutation pressure value refers to the average value of pressure mutation caused by defects on the surface of the valve core and valve body. The processing terminal identifies the defect mutation peak in the test grinding pressure stroke curve, and then calculates the difference between the defect mutation peak and the standard pressure to obtain the defect mutation value. The average value of the defect mutation values ​​is then calculated to obtain the defect mutation pressure value. By determining the defect mutation pressure value, data support is provided for subsequent analysis of the impact of defect residue on rotational speed.

[0169] Step S704: Correct the product of the first correction coefficient and the second correction coefficient according to the defect mutation pressure value to generate the speed correction coefficient.

[0170] In this step, the speed correction coefficient is the same as that in step S603. The processing terminal first calculates the product of the first correction coefficient and the second correction coefficient, and then corrects the product by the defect sudden change pressure value. This comprehensively considers the influence of three dimensions—the average pressure, the degree of pressure fluctuation, and the defect impact—on the speed to obtain the speed correction coefficient. The specific method is as follows: Figure 8 This process ensures the accuracy of the speed correction coefficient.

[0171] Reference Figure 8 The step of correcting the product of the first correction factor and the second correction factor based on the defect mutation pressure value to generate the speed correction factor includes:

[0172] Step S800: Calculate the quotient of the defect mutation pressure value and the sampling standard pressure to generate the defect influence coefficient.

[0173] Among them, the defect influence coefficient refers to the influence coefficient of the defect on the pressure. It is obtained by calculating the quotient of the defect sudden pressure value and the sampling standard pressure from the processing terminal. Defects on the surface of the valve body and valve core can cause the pressure to be artificially high or low. The larger the defect influence coefficient, the greater the degree of influence.

[0174] Step S801: Calculate the difference between the preset no-influence coefficient and the defect influence coefficient to generate the defect influence correction coefficient.

[0175] The no-effect coefficient refers to the correction coefficient for the rotational speed when there are no defects, which is 1.

[0176] The defect impact correction coefficient refers to the correction coefficient for the speed caused by the defect. It is obtained by calculating the difference between the no-impact coefficient and the defect impact coefficient at the processing terminal. When the defect impact coefficient is larger, the defect impact correction coefficient is smaller. In this case, the adjustment range of the speed is reduced to avoid over-correction of the speed.

[0177] Step S802: Calculate the product of the first correction factor, the second correction factor, and the defect influence correction factor to generate the speed correction factor.

[0178] In this step, the speed correction coefficient is the same as that in step S704. It is obtained by the processing terminal by calculating the product of the first correction coefficient, the second correction coefficient, and the defect influence correction coefficient. The first correction coefficient is used to bring the pressure between the valve core and the valve body during grinding back to the normal range, ensuring the stability of grinding. The second correction coefficient is used to keep the pressure between the valve core and the valve body during grinding stable, avoiding damage caused by strong fluctuations. Finally, the defect influence correction coefficient is used to limit the adjustment range of the speed, preventing excessive speed correction due to defects, which could cause damage to other parts.

[0179] Based on the same inventive concept, embodiments of this application provide a PLC-based eccentric rotary valve machining control system, including:

[0180] The data acquisition module is used to acquire data on the current grinding stage, the test grinding pressure-stroke curve, the variable speed pressure-stroke curve, and the defect sudden change pressure value.

[0181] The memory is used to store the program for the PLC-based eccentric rotary valve machining control method;

[0182] The processor can load and execute programs in memory to implement a PLC-based eccentric rotary valve machining control method.

[0183] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional modules is used as an example. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. The specific working process of the system, device, and unit described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0184] This application provides a computer-readable storage medium storing a computer program that can be loaded and executed by a processor, representing a PLC-based eccentric rotary valve machining control method.

[0185] Computer storage media include, for example, USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, optical disks, and other media that can store program code.

[0186] Based on the same inventive concept, this application provides an intelligent terminal, including a memory and a processor. The memory stores a computer program that can be loaded and executed by the processor to control the processing of an eccentric rotary valve based on a PLC.

[0187] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional modules is used as an example. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. The specific working process of the system, device, and unit described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0188] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Any feature disclosed in this specification (including the abstract and drawings) may be replaced by other equivalent or similar features unless specifically stated otherwise. That is, unless specifically stated otherwise, each feature is only one example of a series of equivalent or similar features.

Claims

1. A PLC-based method for controlling the machining of eccentric rotary valves, characterized in that, include: Collect the current grinding stage of the preset valve core and preset valve body; Based on the current grinding stage, find the corresponding empirical grinding speed from the preset stage grinding speed relationship; The valve core and valve body were tested using an empirical grinding speed, and the test grinding pressure-stroke curves were collected. The pressure-stroke curve of the trial grinding was analyzed to generate a speed correction coefficient; The empirical grinding speed is corrected based on the speed correction coefficient to generate a corrected grinding speed; In response to adjust the grinding speed for mating grinding of the valve core and valve body.

2. The PLC-based eccentric rotary valve machining control method according to claim 1, characterized in that, The steps for analyzing the pressure-stroke curve of the trial grinding to generate the speed correction factor include: Based on the current grinding stage, find the corresponding standard pressure-stroke curve in the preset stage pressure-stroke relationship; The pressure stroke curve of the trial grinding is denoised based on the standard pressure stroke curve to generate an accurate pressure stroke curve; The standard pressure stroke curve and the precise pressure stroke curve are sampled synchronously according to the preset sampling sliding window to generate the sampling standard pressure and the sampling test grinding pressure. Calculate the difference between the sampling standard pressure and the sampling test grinding pressure to generate the test grinding pressure difference value; Determine whether the difference in test grinding pressure is greater than the preset reference pressure difference value; If it is not greater than, then the preset uncorrected coefficient is defined as the speed correction coefficient; If the difference is greater than the standard sampling pressure and the sampling test grinding pressure, then the difference between the standard sampling pressure and the test grinding pressure is quantified to generate a speed correction coefficient.

3. The PLC-based eccentric rotary valve machining control method according to claim 2, characterized in that, The steps for reducing noise in the test grinding pressure stroke curve based on the standard pressure stroke curve to generate an accurate pressure stroke curve include: Calculate the average pressure of the standard pressure stroke curve to generate a noise-reduced standard pressure; The test grinding pressure stroke curve is sampled synchronously according to the preset sampling sliding window to generate the pressure to be tested and the corresponding stroke to be tested; Determine whether the pressure to be tested is consistent with the noise reduction standard pressure; If so, the pressure to be tested will be determined as the noise-reduced pressure; If not, then the pressure to be tested is denoised according to the denoising standard pressure to generate a denoised pressure; A precise pressure-stroke curve is redrawn based on the noise-reduced pressure and the stroke to be detected.

4. The PLC-based eccentric rotary valve machining control method according to claim 3, characterized in that, The steps for reducing the noise of the pressure to be tested according to the noise reduction standard pressure to generate the noise-reduced pressure include: The test pressure for the same stroke is obtained by sampling from the test grinding pressure-stroke curve based on the stroke to be tested. Determine whether the pressure detected in the same stroke is consistent with the pressure to be detected; If they match, the valve core and valve body are ground according to the preset noise reduction grinding speed to determine the noise reduction pressure. If they are inconsistent, the pressure to be tested corresponding to the stroke to be tested is replaced with the noise-reduced standard pressure to generate the noise-reduced pressure.

5. The PLC-based eccentric rotary valve machining control method according to claim 4, characterized in that, The steps for grinding the valve core and valve body according to the preset noise-reducing grinding speed to determine the noise-reduced pressure include: The valve core and valve body are ground according to the preset noise reduction grinding speed, and the variable speed pressure stroke curve is collected. The variable speed stroke detection pressure is obtained by sampling from the variable speed pressure stroke curve based on the stroke to be detected. Determine whether the pressure detected during the shift stroke is consistent with the pressure to be detected; If they match, the pressure to be tested corresponding to the stroke to be tested is replaced with the noise-reduced standard pressure to generate the noise-reduced pressure; If there is a discrepancy, the pressure to be tested will be determined as the noise-reduced pressure.

6. The PLC-based eccentric rotary valve machining control method according to claim 2, characterized in that, The steps for quantifying the difference between the standard sampling pressure and the sampled grinding pressure to generate a rotational speed correction factor include: Calculate the mean of the sampled standard pressures to generate the standard pressure mean; Calculate the mean value of the sampled grinding pressure to generate the mean value of the grinding pressure; Calculate the quotient of the average standard pressure and the average test grinding pressure to generate the first correction factor; The first correction factor is adjusted based on the fluctuation of the sampling standard pressure and the sampling test grinding pressure to generate the rotational speed correction factor.

7. The PLC-based eccentric rotary valve machining control method according to claim 6, characterized in that, The steps for generating the rotational speed correction coefficient by correcting the first correction coefficient based on the fluctuation of the sampling standard pressure and the sampling test grinding pressure include: Calculate the standard deviation of the sampled standard pressure to generate standard pressure fluctuation values; Calculate the standard deviation of the sampled grinding pressure to generate the grinding pressure fluctuation value; Calculate the quotient of the standard pressure fluctuation value and the test grinding pressure fluctuation value to generate a second correction factor; Collect defect mutation stress values; The product of the first correction factor and the second correction factor is corrected based on the defect mutation pressure value to generate the speed correction factor.

8. The PLC-based eccentric rotary valve machining control method according to claim 7, characterized in that, The steps for generating the speed correction coefficient by correcting the product of the first and second correction coefficients based on the defect mutation pressure value include: Calculate the quotient of the defect mutation pressure value and the sampling standard pressure to generate the defect influence coefficient; Calculate the difference between the preset no-impact coefficient and the defect impact coefficient to generate the defect impact correction coefficient; Calculate the product of the first correction factor, the second correction factor, and the defect influence correction factor to generate the speed correction factor.

9. A PLC-based eccentric rotary valve machining control system, characterized in that, include: The data acquisition module is used to acquire data on the current grinding stage and the pressure-stroke curve of the trial grinding process. A memory for storing the program of the PLC-based eccentric rotary valve machining control method as described in any one of claims 1 to 8; The processor and the program in the memory can be loaded and executed by the processor to implement the PLC-based eccentric rotary valve machining control method as described in any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that, The computer program is stored that can be loaded by a processor and executed as described in any one of claims 1 to 8, which is a PLC-based eccentric rotary valve machining control method.

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