High-quality machining method of valve body based on CNC machining center

Abstract

The present application relates to the field of high-quality processing technology, and specifically to a high-quality processing method for valve bodies based on CNC machining centers, the method comprising: real-time collection of power data, cutting force data, feed speed data, and rotation speed data when a CNC machine tool processes a valve body; determining the operation matching index of the cutting force and rotation speed at any of the acquisition moments; combining the operation matching index of the cutting force and rotation speed at any of the acquisition moments to obtain the machine operation matching index of the CNC machine tool at any of the acquisition moments; determining the feed speed abnormality factor of the CNC machine tool at any of the acquisition moments; and adjusting the linear speed in the spindle speed control instruction at the current acquisition moment based on the feed speed abnormality factor at the current acquisition moment. The present application aims to achieve high-quality processing of the valve body by adjusting the feed speed during the valve body processing process to reduce surface roughness and tool wear.

Description

Technical Field

[0001] The present application relates to the technical field of high-quality machining, and in particular to a method for high-quality machining of a valve body based on a numerical control machining center. Background Art

[0002] With the development of science and technology, especially in precision engineering and industrial automation, CNC machining technology has become a key factor in improving product quality and production efficiency. As the core component for controlling fluid flow, the valve body plays a vital role in many industries such as petroleum, chemical, and energy. The application of CNC machining centers in valve body processing not only improves production efficiency and product quality, but also promotes the manufacturing industry to develop in a higher precision, higher automation and more sustainable direction.

[0003] When processing the valve body, constant linear speed control is mainly used to regulate the feed speed. However, due to the influence of various factors such as material properties, processing technology and tool selection, the feed speed of CNC machine tools when processing valve bodies is not constant. The feed speed of CNC machine tools has a significant impact on the accuracy of valve body processing. If the feed speed is too fast, the contact time between the tool and the workpiece will be shortened, thereby increasing the cutting temperature and tool wear, which will affect the quality of the processed surface. At the same time, too fast a feed speed may also cause vibration of the machine tool structure and deformation of the workpiece. In addition, the unevenness of the feed speed will also cause processing errors, especially when processing complex surfaces. Sudden changes in the feed speed may cause deviations in the processing path and affect the processing accuracy. Summary of the invention

[0004] In view of the above, it is necessary to provide a high-quality valve body machining method based on a CNC machining center. Compared with the traditional high-quality valve body machining method, the high-quality machining of the valve body can be achieved by adjusting the feed speed during the valve body machining process, reducing the surface roughness and tool wear.

[0005] The high-quality valve body processing method based on the CNC machining center of this application adopts the following technical solutions:

[0006] One embodiment of the present application provides a high-quality machining method for a valve body based on a CNC machining center, the method comprising the following steps:

[0007] Real-time collection of power data, cutting force data, feed speed data and speed data when CNC machine tools process valve bodies;

[0008] The time at which each abnormal power data is located before any collection time and its multiple neighboring collection time constitute each time window, and based on the discrete degree of all cutting force data and all rotational speed data in each time window, as well as the difference between the cutting force data in each time window and the overall cutting force data, and the difference between the rotational speed data and the overall rotational speed data, the operation matching index of the cutting force and the rotational speed at any collection time is determined respectively;

[0009] Combining the operation matching index of the cutting force and the rotation speed at any of the acquisition moments, the machine operation matching index of the CNC machine tool at any of the acquisition moments is obtained;

[0010] By analyzing the correlation between the feed speed data and the cutting force data, the correlation between the feed speed data and the rotational speed data before any of the acquisition moments, and the change of the cutting force data and the rotational speed data when the feed speed data changes, and combining the machine tool operation matching index, the feed speed abnormality factor of the CNC machine tool at any of the acquisition moments is determined;

[0011] Based on the feed speed abnormality factor at the current acquisition moment, the linear speed in the spindle speed control instruction at the current acquisition moment is adjusted.

[0012] In one embodiment, each time window is a window constructed with the time at which each abnormal power data is located as the center.

[0013] In one embodiment, the process of determining the operation matching index of the cutting force and the rotation speed at any acquisition time is as follows:

[0014] Arrange the cutting force data and the rotation speed data at any collection time and all the collection times before the collection time in time sequence to form a cutting force sequence and a rotation speed sequence;

[0015] Calculate the mean of all cutting force data in the cutting force series;

[0016] Calculate the average value of the difference between all cutting force data in each time window and the mean value;

[0017] The operation matching index of the cutting force at any acquisition moment is positively correlated with the discrete degree of all cutting force data in each time window and the average value;

[0018] For the rotation speed data, the operation matching index of the rotation speed at any acquisition moment is calculated according to the same calculation method as the operation matching index of the cutting force at any acquisition moment.

[0019] In one embodiment, the expression of the operation matching index of the cutting force at any acquisition moment is:

[0020] ; In the formula, represents the operation matching index of the cutting force at the i-th acquisition moment; Represents the total number of time windows before the i-th acquisition moment; represents the average value in the f-th time window before the i-th acquisition moment; It represents the discrete degree of all cutting force data in the fth time window before the i-th acquisition moment.

[0021] In one embodiment, the machine tool operation matching index is the average of the operation matching index of the cutting force and the operation matching index of the rotation speed at any acquisition moment.

[0022] In one embodiment, the process of determining the feed speed abnormality factor is as follows:

[0023] Arrange the feed speed data at any one acquisition time and all previous acquisition times in time sequence to form a feed speed sequence;

[0024] Calculate the correlation coefficient between the feed speed sequence and the cutting force sequence, and the correlation coefficient between the feed speed sequence and the rotation speed sequence at any acquisition moment, which are recorded as the first correlation coefficient and the second correlation coefficient respectively;

[0025] The feed speed data and cutting force data at each acquisition time are combined into two-dimensional data points, which are recorded as cutting data points; the feed speed data and rotation speed data at each acquisition time are combined into two-dimensional data points, which are recorded as rotation speed data points;

[0026] Respectively obtain the fitting straight lines of the cutting data points and the rotation speed data points at any acquisition time and all the acquisition times before the above, and record them as the first fitting straight line and the second fitting straight line;

[0027] The feed speed abnormality factor is obtained by combining the first correlation coefficient, the second correlation coefficient, the slope of the first fitting straight line, the slope of the second fitting straight line and the machine tool operation matching index.

[0028] In one embodiment, the feed speed abnormality factor is expressed as:

[0029] ; In the formula, It represents the abnormal feed speed factor of the CNC machine tool at the i-th acquisition moment; represents the mean of the first correlation coefficient and the second correlation coefficient at the i-th acquisition moment; represents the average of the slope of the first fitting straight line and the slope of the second fitting straight line at the i-th acquisition moment; It represents the machine operation matching index of the CNC machine tool at the i-th acquisition moment.

[0030] In one of the embodiments, during the adjustment of the linear speed in the spindle speed control instruction, if the normalized value of the feed speed abnormality factor of the CNC machine tool at the current moment is less than or equal to a preset threshold value, the linear speed in the spindle speed control instruction is not adjusted; otherwise, the linear speed in the spindle speed control instruction is adjusted.

[0031] In one embodiment, the expression for adjusting the linear velocity in the spindle speed control instruction is:

[0032] ; In the formula, Indicates the adjusted linear speed in the main axis speed control instruction at the i-th acquisition moment; Indicates the linear speed before adjustment in the main axis speed control instruction at the i-th acquisition moment; μ is a value preset to be greater than 0; represents the feed speed abnormality factor of the CNC machine tool at the i-th acquisition moment; norm() represents the normalization function; T represents the preset threshold.

[0033] In one embodiment, when When the value of is less than the preset minimum linear speed, the preset minimum linear speed is assigned to .

[0034] This application has at least the following beneficial effects:

[0035] The present application aims at the problem of the matching degree between cutting force and spindle power in the process of CNC machine tool processing, analyzes the fluctuation of cutting force data during the time period when power abnormality occurs, and the degree of deviation of cutting force relative to the overall cutting force during the time period when power abnormality occurs, thereby improving the accuracy of the coordination analysis between energy consumption change and cutting force control; then, based on the operation matching index of cutting force and speed, the machine operation matching index of CNC machine tool is obtained to reflect the matching of cutting force change, speed change and spindle power change; further, combined with the correlation between feed speed change and cutting force change, feed speed change and the matching degree between feed speed change and spindle power change, the matching degree between feed speed change and spindle power change is obtained; The feed speed anomaly factor of the CNC machine tool can be obtained by analyzing the correlation between the change in cutting force and the change in speed, as well as the sensitivity of the change in cutting force and speed to the change in feed speed. This can accurately reflect the impact of the feed speed on the operating parameters of the CNC machine tool, and avoid misjudging the cutting force change or speed change caused by other factors as being caused by the feed speed change. The linear speed in the spindle speed control instruction is adjusted based on the feed speed anomaly factor, which improves the accuracy of the feed speed adjustment. Then, the valve body is processed based on the adjusted feed speed, which can reduce the surface roughness of the valve body and the tool wear, thereby achieving high-quality processing of the valve body. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0037] Figure 1 A flowchart of the steps of the high-quality machining method of the valve body based on the CNC machining center provided in this application;

[0038] Figure 2 It is a schematic diagram of the process of determining the operation matching index of the cutting force;

[0039] Figure 3 Schematic diagram of the process of determining the feed speed abnormality factor. DETAILED DESCRIPTION

[0040] In the description of the embodiments of the present application, words such as "exemplary", "or", "for example" and the like are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary", "or", "for example" and the like is intended to present related concepts in a concrete manner.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the present application. The terms used in the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. It should be understood that, unless otherwise specified, " / " means or.

[0042] It should also be noted that the terms "first" and "second" in the present application are used to distinguish similar objects rather than to describe a specific order or sequence.

[0043] The specific scheme of the high-quality valve body processing method based on a CNC machining center provided by the present application is described in detail below in conjunction with the accompanying drawings.

[0044] An embodiment of the present application provides a high-quality valve body processing method based on a CNC machining center. Specifically, the following high-quality valve body processing method based on a CNC machining center is provided. Figure 1 , the method comprises the following steps:

[0045] Step 1: Real-time collection of power data, cutting force data, feed speed data and rotation speed data when the CNC machine tool processes the valve body.

[0046] Collect various relevant data when CNC machine tools process valve bodies, specifically: install a power sensor on the spindle of the CNC machine tool to collect spindle power data; install a capacitive force sensor in the contact area between the tool and the workpiece of the CNC machine tool to collect cutting force data; in the control system of the CNC machine tool, collect spindle speed data and feed speed data through the Programmable Logic Controller (PLC).

[0047] In this embodiment, the acquisition frequency for collecting various data is set to 20 Hz. The value of the acquisition frequency is preset manually and can be set by the implementer. This application does not impose any special restrictions.

[0048] Taking the i-th acquisition moment as an example, the power data, cutting force data, feed speed data, and speed data of the i-th acquisition moment and all previous acquisition moments are arranged in time sequence to form the power sequence, cutting force sequence, feed speed sequence, and speed sequence of the i-th acquisition moment. In order to eliminate the influence of dimension, the power sequence, cutting force sequence, feed speed sequence, and speed sequence are normalized respectively.

[0049] In this embodiment, the Min-Max normalization method is used to normalize the power sequence, cutting force sequence, feed speed sequence, and rotational speed sequence. As other implementation methods, on the basis of being able to realize normalization of the power sequence, cutting force sequence, feed speed sequence, and rotational speed sequence, the implementer may use other existing technologies for normalization, such as the Z-Score normalization method, the decimal calibration normalization method, etc., and this application does not impose any special restrictions.

[0050] Step 2, the time when each abnormal power data is located before any collection time and its multiple neighboring collection time are combined into each time window, based on the discrete degree of all cutting force data and all speed data in each time window, as well as the difference between the cutting force data in each time window and the overall cutting force data, and the difference between the speed data and the overall speed data, respectively determine the operation matching index of the cutting force and the speed at any collection time; obtain the machine operation matching index of the CNC machine tool at any collection time.

[0051] When machining valve bodies with CNC machine tools, the power sequence reflects the change in energy consumption of the spindle under different load conditions, which is directly related to the rationality of the feed speed; too high or too low a feed speed may lead to power abnormalities, affecting machining efficiency and product quality. The cutting force sequence shows the change in force during the cutting process. An inappropriate feed speed will cause cutting force fluctuations, resulting in increased surface roughness of the valve body or increased tool wear; the speed sequence reflects the operating status of the spindle. An inappropriate feed speed may lead to unstable speed, which in turn affects the machining accuracy and surface finish of the valve body. Improper matching between power, cutting force and speed will lead to an uncoordinated machining process and affect the quality of valve body machining.

[0052] All abnormal power data in the power sequence at the i-th collection moment are obtained. At the moment of each abnormal power data, the spindle encounters an unexpected high load or low load situation. The moment of each abnormal power data and its multiple neighboring collection moments form each time window.

[0053] In this embodiment, the Pettitt mutation point detection algorithm is used to obtain abnormal power data in the power sequence. As other implementation methods, on the basis of being able to obtain abnormal power data in the power sequence, the implementer may adopt other existing technologies, such as the Bayesian mutation point detection algorithm, the Mann-Kendall mutation point detection algorithm, etc., and this application does not make any special restrictions.

[0054] In this embodiment, each time window is a window constructed with the time at which each abnormal power data is located as the center, and the size of the window is 1×55. The size of the window is preset manually and can be set by the implementer. This application does not impose any special restrictions. If the length of the window exceeds the length of the power sequence, the excess part is filled with data.

[0055] In this embodiment, the mean filling method is used for data filling. As other implementation methods, on the basis of achievable data filling, the implementer may use other existing technologies for data filling, such as the median filling method, interpolation method, etc., and this application does not impose any special restrictions.

[0056] Calculate the mean of all cutting force data in the cutting force sequence, calculate the difference between each cutting force data in each time window and the mean, record it as the cutting force difference, and calculate the average value of all the cutting force differences in each time window.

[0057] In this embodiment, the difference between the cutting force data and the mean is the square of the difference. As other implementation methods, on the basis of being able to measure the difference between the cutting force data and the mean, the implementer may adopt other calculation methods, such as the absolute value of the difference, the ratio, etc., and this application does not impose any special restrictions.

[0058] Based on the discrete degree of the cutting force data in all time windows and the average value in all time windows, the operation matching index of the cutting force at the i-th acquisition moment is determined, and the expression is:

[0059] ; In the formula, represents the operation matching index of the cutting force at the i-th acquisition moment; Represents the total number of time windows before the i-th acquisition moment; represents the average value in the f-th time window before the i-th acquisition moment; It represents the discrete degree of all cutting force data in the fth time window before the i-th acquisition moment.

[0060] In this embodiment, the degree of discreteness is the standard deviation. As other implementation methods, on the basis of being able to measure the uneven distribution of cutting force data in each time window, the implementer may use other existing technologies for measurement, such as variance, coefficient of variation, etc., and this application does not impose any special restrictions.

[0061] It should be noted that the degree of dispersion It reflects the stability of the cutting force in the time window of the shaft power abnormality. If the discrete degree value is smaller, it means that the cutting force changes less in each time window, that is, when the shaft power is abnormal, the cutting force does not change to match it, and the value of the running matching index of the cutting force at the i-th acquisition time is smaller; the average value It reflects the degree of deviation between the cutting force in the fth time window and the overall cutting force mean. If the mean value is larger, it means that the degree of deviation of the cutting force in the fth time interval is larger, that is, when the shaft power is abnormal, the cutting force has a more matching change with it, and the value of the operation matching index of the cutting force at the i-th acquisition moment is larger; the larger the value of the operation matching index, the more matching the fluctuation of the cutting force with the power change of the shaft during the processing, and the more coordinated the force control and energy consumption change. The schematic diagram of the process of determining the operation matching index of the cutting force is shown in the figure. Figure 2 shown.

[0062] For the rotation speed data, the operation matching index of the rotation speed at the i-th collection moment is calculated according to the same calculation method as the operation matching index of the cutting force at the i-th collection moment.

[0063] The average of the operation matching index of the cutting force at the i-th acquisition moment and the operation matching index of the rotation speed at the i-th acquisition moment is taken as the machine operation matching index of the CNC machine tool at the i-th acquisition moment.

[0064] Step 3, by analyzing the correlation between the feed speed data and the cutting force data, the correlation between the feed speed data and the rotational speed data before any of the collection moments, and the changes in the cutting force data and the rotational speed data when the feed speed data changes, and combining with the machine tool operation matching index, determine the feed speed abnormality factor of the CNC machine tool at any of the collection moments.

[0065] CNC machine tools usually use constant linear speed control during the processing process. Constant linear speed means that the speed of the tool moving along the workpiece surface remains constant during the cutting process. This control method can improve the processing accuracy and surface quality, because the constant tool movement speed can reduce the vibration and impact during the processing and improve the cutting effect. However, due to the influence of various factors such as material properties, processing technology and tool selection, the feed speed of CNC machine tools when processing valve bodies is not constant. Therefore, the feed speed needs to be dynamically adjusted to maintain a constant cutting speed. However, when the feed speed is not adjusted properly, it will cause cutting force fluctuations and unstable speed. If the feed speed is too high or too low, it will cause power abnormality, affecting processing efficiency and product quality.

[0066] Based on the above analysis, the correlation coefficients between the feed speed sequence and the cutting force sequence, and the correlation coefficients between the feed speed sequence and the speed sequence are calculated, recorded as the first correlation coefficient and the second correlation coefficient, and the feed speed data and the cutting force data at each acquisition time are combined into two-dimensional data points, recorded as cutting data points, and the feed speed data and the speed data at each acquisition time are combined into two-dimensional data points, recorded as speed data points; the fitting straight lines of the cutting data points and the speed data points at the i-th acquisition time and all the previous acquisition times are obtained, respectively, and recorded as the first fitting straight line and the second fitting straight line. In the process of obtaining the first fitting straight line and the second fitting straight line, the horizontal coordinates are the feed speed, and the vertical coordinates are the cutting force and the speed, respectively.

[0067] In this embodiment, the correlation coefficient between the feed speed sequence and the cutting force sequence, and the correlation coefficient between the feed speed sequence and the rotational speed sequence are both Pearson correlation coefficients. As other implementation methods, on the basis of being able to measure the correlation between the feed speed sequence and the cutting force sequence, and the correlation between the feed speed sequence and the rotational speed sequence, the implementer may adopt other existing technologies for measurement, such as the Spearman correlation coefficient, the Kendall rank correlation coefficient, etc., and this application does not impose any special restrictions.

[0068] In this embodiment, the least squares straight line fitting method is used to obtain the fitting straight line. As other implementation methods, on the basis of obtaining the fitting straight line of the cutting data points and the rotational speed data points, the implementer can use other existing technologies to obtain the fitting straight line of the cutting data points and the rotational speed data points, such as linear regression analysis, weighted least squares method, etc., and this application does not impose any special restrictions.

[0069] Further, based on the first correlation coefficient, the second correlation coefficient, the slope of the first fitting straight line, the slope of the second fitting straight line and the machine tool operation matching index, the feed speed abnormality factor of the CNC machine tool at the i-th acquisition time is jointly determined, and the expression is:

[0070] ; In the formula, It represents the abnormal feed speed factor of the CNC machine tool at the i-th acquisition moment; represents the mean of the first correlation coefficient and the second correlation coefficient at the i-th acquisition moment; represents the average of the slope of the first fitting straight line and the slope of the second fitting straight line at the i-th acquisition moment; It represents the machine operation matching index of the CNC machine tool at the i-th acquisition moment.

[0071] It should be noted that: As an influence weight, the significance is to quantify the possibility of feed speed affecting the operating parameters of CNC machine tools. Reflects the correlation between feed speed change and cutting force change, and the correlation between feed speed change and speed change, average The larger the value, the more consistent the changing trends of feed speed, cutting force and rotation speed are; the absolute value Indicates the average change in cutting force and speed for every unit change in feed speed, absolute value The magnitude of reflects the sensitivity of cutting force changes and rotation speed changes to feed speed changes; It is a quantitative indicator of the effect of feed speed on cutting force and speed. The larger its value, the greater the possibility of changes in the CNC machine tool operating parameters caused by changes in feed speed. It reflects the fluctuation of cutting force and speed when the shaft power is abnormal, as well as the deviation between the cutting force and the overall cutting force mean, and the deviation between the speed and the overall speed mean. The larger the value, the more closely the changes in cutting force and rotation speed match the changes in shaft power during valve body machining. The larger the value of the feed speed abnormality factor, the greater the overall impact of the feed speed on the CNC machine tool, that is, the change in feed speed will cause a stronger overall parameter deviation in the CNC machine tool, thus affecting the coordination of the machining process and product quality. The flow chart for determining the feed speed abnormality factor is shown in the figure below. Figure 3 shown.

[0072] Step 4: Based on the feed speed abnormality factor at the current acquisition moment, adjust the linear speed in the constant linear speed control at the current acquisition moment.

[0073] The present application adjusts the linear speed in the spindle speed control instruction according to the value of the feed speed abnormality factor. In this embodiment, the spindle speed control instruction is the G96 instruction. If the value of the feed speed abnormality factor is large, the linear speed can be appropriately reduced to reduce the impact of the feed speed change on the cutting force and rotation speed, thereby reducing the abnormality. The specific adjustment method is:

[0074] If the normalized value of the feed speed abnormality factor of the CNC machine tool at the current moment is less than or equal to the preset threshold, the linear speed in the spindle speed control instruction is not adjusted; otherwise, the linear speed in the spindle speed control instruction is adjusted, and the expression is:

[0075] ; In the formula, Indicates the adjusted linear speed in the main axis speed control instruction at the i-th acquisition moment; Indicates the linear speed before adjustment in the spindle speed control instruction at the i-th acquisition moment; μ is a value greater than 0, which is used to determine the amplitude of linear speed adjustment. The larger the μ value, the greater the linear speed adjustment. The more sensitive the response; represents the feed speed abnormality factor of the CNC machine tool at the i-th acquisition moment; norm() represents the normalization function; T represents the preset threshold.

[0076] It should be noted that: in order to avoid the adjusted linear speed being too small or too large, the adjusted linear speed is further processed. The specific process is: when the adjusted linear speed is less than the minimum linear speed, the minimum linear speed is used as the adjusted linear speed in the G96 instruction; when the adjusted linear speed is greater than the maximum linear speed, the maximum linear speed is used as the adjusted linear speed in the G96 instruction. Among them, the minimum linear speed and the maximum linear speed are both determined according to the linear speed at the first moment when the valve body is processed. In this embodiment, the minimum linear speed and the maximum linear speed are 0.9 times and 1.1 times the linear speed at the first moment, respectively. It should be noted that 0.9 and 1.1 are only an embodiment of the present application. The specific value can be determined according to the tool type, the material of the processed valve body and the complexity of the processing.

[0077] In this embodiment, the value of the preset threshold is 0.8. The value of the preset threshold is preset manually and can be set by the implementer. This application does not impose any special restrictions.

[0078] In this embodiment, the Sigmoid function is used to obtain the normalized value of the feed speed abnormality factor. As other implementation methods, on the basis of being able to obtain the normalized value of the feed speed abnormality factor, the implementer may use other existing technologies to obtain the normalized value of the feed speed abnormality factor, such as the hyperbolic tangent function, decimal calibration normalization method, etc., and this application does not make any special restrictions.

[0079] In this embodiment, in order to avoid excessive adjustment of the linear speed and affect the valve body processing quality, the value of μ is 2. The value of μ is preset manually and can be set by the implementer. This application does not impose any special restrictions.

[0080] According to the same method as adjusting the linear speed in the spindle speed control instruction at the i-th acquisition moment, the linear speed at each acquisition moment is adjusted to achieve segmented control of constant linear speed. By dynamically adjusting the feed speed, the abnormalities caused by feed speed changes during the machining process of the CNC machine tool can be effectively dealt with, thereby reducing surface roughness and tool wear, improving machining accuracy and product quality, and achieving high-quality machining of the valve body. It should be noted that if there is insufficient data when adjusting the linear speed during the valve body machining process, resulting in an inability to adjust, the linear speed will not be adjusted.

[0081] In summary, the present application aims at the problem of the matching degree between cutting force and spindle power in the process of CNC machine tool processing, analyzes the fluctuation of cutting force data during the time period when power abnormality occurs, and the degree of deviation of cutting force relative to the overall cutting force during the time period when power abnormality occurs, thereby improving the accuracy of the coordination analysis between energy consumption change and cutting force control; then, based on the operation matching index of cutting force and speed, the machine operation matching index of CNC machine tool is obtained to reflect the matching of cutting force change, speed change and shaft power change; further, combined with the correlation between feed speed change and cutting force change, feed speed change and the matching degree between feed speed change and cutting force change, the matching degree between feed speed change and cutting force change is analyzed. The correlation between speed change and rotational speed change, as well as the sensitivity of cutting force change and rotational speed change to feed speed change, can be used to obtain the feed speed anomaly factor of the CNC machine tool, which can accurately reflect the impact of the feed speed on the operating parameters of the CNC machine tool, and avoid misjudging the cutting force change or rotational speed change caused by other factors as caused by the feed speed change; the linear speed in the spindle speed control instruction is adjusted based on the feed speed anomaly factor, which improves the accuracy of the feed speed adjustment, and then the valve body is processed based on the adjusted feed speed, which can reduce the surface roughness of the valve body and tool wear, thereby achieving high-quality processing of the valve body.

[0082] The flowchart and block diagram in the accompanying drawings show the possible architecture, function and operation of the system, method and computer program product according to the embodiment of the present disclosure. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of the code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. In some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. In the description corresponding to the flowchart and the block diagram in the accompanying drawings, the operations or steps corresponding to different boxes can also occur in a different order from the order disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. Each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented by a dedicated hardware-based system that performs the specified functions or actions, or may be implemented by a combination of dedicated hardware and computer instructions.

[0083] It is obvious to those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and that the present application can be implemented in other specific forms without departing from the basic features of the present application. Therefore, no matter from which point of view, the above embodiments of the present application should be regarded as exemplary and non-restrictive.

Claims

1. High-quality machining method for valve body based on CNC machining center, characterized in that: The method comprises the following steps: Real-time collection of power data, cutting force data, feed speed data and speed data when CNC machine tools process valve bodies; The time at which each abnormal power data is located before any collection time and its multiple neighboring collection time constitute each time window, and based on the discrete degree of all cutting force data and all rotational speed data in each time window, as well as the difference between the cutting force data in each time window and the overall cutting force data, and the difference between the rotational speed data and the overall rotational speed data, the operation matching index of the cutting force and the rotational speed at any collection time is determined respectively; Combining the operation matching index of the cutting force and the rotation speed at any of the acquisition moments, the machine operation matching index of the CNC machine tool at any of the acquisition moments is obtained; By analyzing the correlation between the feed speed data and the cutting force data, the correlation between the feed speed data and the rotational speed data before any of the acquisition moments, and the change of the cutting force data and the rotational speed data when the feed speed data changes, and combining the machine tool operation matching index, the feed speed abnormality factor of the CNC machine tool at any of the acquisition moments is determined; Based on the feed speed abnormality factor at the current acquisition moment, the linear speed in the spindle speed control instruction at the current acquisition moment is adjusted.

2. The high-quality valve body machining method based on a CNC machining center according to claim 1 is characterized in that: Each time window is a window constructed with the time at which each abnormal power data is located as the center.

3. The high-quality valve body machining method based on a CNC machining center according to claim 1 is characterized in that: The process of determining the operation matching index of the cutting force and the rotation speed at any acquisition time is as follows: Arrange the cutting force data and the rotation speed data at any collection time and all the collection times before the collection time in time sequence to form a cutting force sequence and a rotation speed sequence; Calculate the mean of all cutting force data in the cutting force series; Calculate the average value of the difference between all cutting force data in each time window and the mean value; The operation matching index of the cutting force at any acquisition moment is positively correlated with the discrete degree of all cutting force data in each time window and the average value; For the rotation speed data, the operation matching index of the rotation speed at any acquisition moment is calculated according to the same calculation method as the operation matching index of the cutting force at any acquisition moment.

4. The high-quality valve body machining method based on a CNC machining center according to claim 3 is characterized in that: The expression of the operation matching index of the cutting force at any acquisition time is: ; In the formula, represents the operation matching index of the cutting force at the i-th acquisition moment; Represents the total number of time windows before the i-th acquisition moment; represents the average value in the f-th time window before the i-th acquisition moment; It represents the discrete degree of all cutting force data in the fth time window before the i-th acquisition moment.

5. The high-quality valve body machining method based on a CNC machining center according to claim 1, characterized in that: The machine tool operation matching index is the average of the operation matching index of the cutting force and the operation matching index of the rotation speed at any acquisition moment.

6. The high-quality valve body machining method based on a CNC machining center as claimed in claim 3, characterized in that: The determination process of the feed speed abnormality factor is as follows: Arrange the feed speed data at any one acquisition time and all previous acquisition times in time sequence to form a feed speed sequence; Calculate the correlation coefficient between the feed speed sequence and the cutting force sequence, and the correlation coefficient between the feed speed sequence and the rotation speed sequence at any acquisition moment, which are recorded as the first correlation coefficient and the second correlation coefficient respectively; The feed speed data and cutting force data at each acquisition time are combined into two-dimensional data points, which are recorded as cutting data points; the feed speed data and rotation speed data at each acquisition time are combined into two-dimensional data points, which are recorded as rotation speed data points; Respectively obtain fitting straight lines of cutting data points and rotation speed data points at any acquisition moment and all acquisition moments before the above, and record them as a first fitting straight line and a second fitting straight line; The feed speed abnormality factor is obtained by combining the first correlation coefficient, the second correlation coefficient, the slope of the first fitting straight line, the slope of the second fitting straight line and the machine tool operation matching index.

7. The high-quality valve body machining method based on a CNC machining center according to claim 6, characterized in that: The expression of the feed speed abnormality factor is: ; In the formula, It represents the abnormal feed speed factor of the CNC machine tool at the i-th acquisition moment; represents the mean of the first correlation coefficient and the second correlation coefficient at the i-th acquisition moment; represents the average of the slope of the first fitting straight line and the slope of the second fitting straight line at the i-th acquisition moment; It represents the machine operation matching index of the CNC machine tool at the i-th acquisition moment.

8. The high-quality valve body machining method based on a CNC machining center according to claim 1, characterized in that: During the adjustment process of the linear speed in the spindle speed control instruction, if the normalized value of the feed speed abnormality factor of the CNC machine tool at the current moment is less than or equal to the preset threshold value, the linear speed in the spindle speed control instruction is not adjusted; otherwise, the linear speed in the spindle speed control instruction is adjusted.

9. The high-quality valve body machining method based on a CNC machining center according to claim 8, characterized in that: The expression for adjusting the linear speed in the spindle speed control instruction is: ; In the formula, Indicates the adjusted linear speed in the main axis speed control instruction at the i-th acquisition moment; Indicates the linear speed before adjustment in the main axis speed control instruction at the i-th acquisition moment; μ is a value preset to be greater than 0; represents the feed speed abnormality factor of the CNC machine tool at the i-th acquisition moment; norm() represents the normalization function; T represents the preset threshold.

10. The high-quality valve body machining method based on a CNC machining center according to claim 9, characterized in that: when When the value of is less than the preset minimum linear speed, the preset minimum linear speed is assigned to ;when When the value of is greater than the preset maximum linear speed, the preset maximum linear speed is assigned to .

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