A grinding method for complex integral impellers

Abstract

This application relates to the technical field of grinding and polishing, and particularly to a grinding method for complex integral impellers, including: obtaining the feeding speed, abrasive flow rate, and impeller temperature of the abrasive flow polishing machine during the impeller grinding and polishing process, obtaining the temperature oscillation value of each temperature subsequence through the temperature change deviation in each temperature subsequence, and combining the flow rate deviation in each flow rate subsequence to obtain the flow rate change degree of the abrasive flow polishing machine in each time period; fitting the flow rate change degree in each time period, analyzing the change trend of the flow rate change degree, and combining the feeding speed of the abrasive flow polishing machine in the current time period to obtain the feeding adjustment speed of the abrasive flow polishing machine in the current time period, and adjusting the feeding valve during the impeller grinding process. This application can improve the grinding quality and efficiency of complex integral impellers.

Description

Technical Field

[0001] The present application relates to the technical field of grinding and polishing, and in particular to a grinding method for a complex integral impeller. Background Art

[0002] Impellers are one of the most typical complex channel parts in the mechanical equipment industry. As key components of power machinery, they operate under harsh conditions and are subject to complex stresses and vibrations. Their design and manufacturing often require knowledge of multiple disciplines, such as fluid mechanics and tribology. Therefore, the overall performance of an impeller product is determined by its machining precision and quality. The grinding process for integral impellers includes two steps: cutting and grinding and polishing. Grinding and polishing are used to improve the roughness of the impeller surface, effectively enhancing its smoothness and improving product quality.

[0003] The grinding of the integral impeller with traditional technology is generally done by an abrasive flow polishing machine. For fields such as aviation and aerospace that require higher precision of devices, the impeller has a complex structure, uneven thickness and complex free-form surfaces. The abrasive flow polishing machine with a fixed abrasive entry speed is prone to abrasive scratches on the impeller surface during the later grinding process, causing problems with the overall impeller processing quality. Summary of the invention

[0004] In order to solve the above technical problems, the present application provides a grinding method for a complex integral impeller to solve the existing problems.

[0005] A grinding method for a complex integral impeller in this application adopts the following technical solution:

[0006] One embodiment of the present application provides a grinding method for a complex integral impeller, comprising the following steps:

[0007] Obtain the feed rate of the abrasive flow polisher in each time period during the impeller grinding and polishing process, as well as the abrasive flow rate and impeller temperature at each sampling moment in each time period;

[0008] For each time period, the impeller temperature and abrasive flow rate at all acquisition moments within the time period are divided into subsequences to obtain temperature subsequences and flow rate subsequences. The temperature oscillation value of each temperature subsequence is obtained based on the temperature variation deviation in each temperature subsequence. The flow rate variation of the abrasive flow polisher in each time period is obtained by combining the flow rate deviation in each flow rate subsequence and the temperature oscillation value of each temperature subsequence.

[0009] Fit the flow rate change degree for each time period, analyze the change trend of the flow rate change degree, and combine the feeding speed of the abrasive flow polishing machine in the current time period to obtain the feeding adjustment speed of the abrasive flow polishing machine in the current time period, and adjust the feeding valve during the impeller grinding process.

[0010] Preferably, each temperature subsequence further includes: the temperatures at all acquisition moments within each time period are arranged in ascending order of time to form the temperature sequence of each time period, and the temperature sequence is evenly divided into multiple subsequences, denoted as each temperature subsequence.

[0011] Preferably, each flow rate subsequence further includes: the abrasive flow rates at all acquisition moments within each time period are arranged in ascending order of time to form the flow rate sequence of each time period, and the flow rate sequence is evenly divided into multiple subsequences, denoted as each flow rate subsequence.

[0012] Preferably, the expression for the temperature oscillation value of each temperature subsequence is:

[0013] ; where, represents the temperature oscillation value of the i-th temperature subsequence; represents the number of temperatures in the temperature subsequence; represents the j-th temperature value in the i-th temperature subsequence; represents the value at the j-th position in the temperature straight line fitted from the i-th temperature subsequence; || represents the absolute value symbol.

[0014] Preferably, the expression for the flow rate change degree of the abrasive flow polishing machine in each time period is:

[0015] ; where, YV represents the flow rate change degree of the abrasive flow polishing machine in the current time period; represents the mean value of all temperature oscillation values corresponding to the current time period; represents the mean value of the flow rate mean deviation sequence; r represents the correlation coefficient between the temperature oscillation value sequence and the flow rate mean deviation sequence; represents a constant to avoid a zero denominator.

[0016] Preferably, the construction of the temperature oscillation value sequence further includes: sorting the temperature oscillation values of all temperature subsequences corresponding to the current time period according to the positions of the temperature subsequences to obtain the temperature oscillation value sequence of the current time period.

[0017] Preferably, the construction of the flow rate mean deviation sequence further includes: statistically calculating the mean absolute deviation of each flow rate subsequence in each time period, and sorting the mean absolute deviations of all flow rate subsequences in each time period according to the positions of the flow rate subsequences to obtain the flow rate mean deviation sequence of each time period.

[0018] Preferably, the expression for the feed adjustment speed of the abrasive flow polishing machine in the current time period is:

[0019] ; where represents the feed adjustment speed of the abrasive flow polishing machine in the current time period; the trend slope of the current time period; represents the set composed of the absolute values of the trend slopes of the current time period and all previous time periods; represents the maximum value function; represents the feed speed of the abrasive flow polishing machine in the current time period; represents a constant to avoid a zero denominator.

[0020] Preferably, the trend slope further includes: performing a linear fitting on the flow rate change degrees of the current time period and all previous time periods, and recording the slope of the straight line as the trend slope of the current time period, where the trend slope of the first time period is set to 0.

[0021] Preferably, the expression for the opening degree of the adjusted feed valve is: ; where is the opening degree of the adjusted feed valve; is the opening degree of the feed valve in the current time period; is the feed speed of the abrasive flow polishing machine in the current time period; represents the feed adjustment speed of the abrasive flow polishing machine in the current time period.

[0022] This application has at least the following beneficial effects:

[0023] In view of the limitations of the existing technology in the grinding processing method of complex integral impellers, due to the complexity of the impeller structure and the diversity of material properties, which cause processing quality problems, this application provides a grinding processing method for complex integral impellers based on sensor data acquisition and intelligent control. By collecting the operation data of the abrasive flow polishing machine in real time, analyzing the temperature changes and flow rate fluctuations during the grinding process to construct a temperature oscillation value sequence, which characterizes the change of the impeller surface roughness; constructing a flow rate average deviation sequence through the flow rate change of the abrasive flow polishing machine, which characterizes the change of the friction force between the abrasive and the impeller surface; combining the temperature oscillation value sequence and the flow rate average deviation sequence, calculating the flow rate change degree, which is used to evaluate the relationship between the impeller surface state and the abrasive state during the grinding process, so as to determine the change of the impeller surface roughness. By calculating the feed adjustment speed of the abrasive flow polishing machine in the current time period through the flow rate change degree, intelligent adjustment during the grinding processing of complex integral impellers is realized, thereby improving the surface quality and processing efficiency of the impeller under various processing conditions. Therefore, this application avoids the processing quality problems caused by the influence of the complexity of the structure and the diversity of material properties in the existing grinding processing method of complex integral impellers, and can effectively improve the processing quality and efficiency of complex integral impellers, making the grinding processing of complex integral impellers more intelligent and accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0025] Figure 1 It is a flowchart of the steps of a grinding processing method for complex integral impellers provided by this application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] In order to further elaborate on the technical means and effects adopted by this application to achieve the intended invention purpose, the following will, in combination with the accompanying drawings and preferred embodiments, detail the specific implementation manners, structures, features, and effects of a grinding processing method for complex integral impellers proposed according to this application. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. In addition, the specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0027] Unless otherwise defined, terms such as "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a circuit structure, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such article or device. Without further limitation, an element defined by the statement "including one..." does not exclude the presence of additional identical elements in the article or device including said element. Additionally, the term "and / or" as used herein includes any and all combinations of one or more of the related listed items. All technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs.

[0028] The following specifically describes the specific solution of a grinding method for a complex integral impeller provided by this application in conjunction with the accompanying drawings.

[0029] A grinding method for a complex integral impeller provided by an embodiment of this application. Specifically, please refer to Figure 1 , including the following steps:

[0030] Step 1: Obtain the feeding speed of the abrasive flow polishing machine at each time period during the impeller grinding and polishing process, as well as the abrasive flow rate and impeller temperature at each acquisition moment within each time period.

[0031] For the grinding of the integral impeller, there are the following two steps in this embodiment:

[0032] S1. Cutting: In this embodiment, through the five-axis machine tool data processing of the blade profile, the tool collects the ball nose taper milling cutter to cut the device raw material, and uses VERICUT software for simulation. The ball nose taper milling cutter includes two main structures: a tool shank and a taper tool body. The taper tool body is provided with a number of conical cutting edges, which are spiral. The spiral angle of the conical cutting edges is 30°; the bottom of the taper tool body is spherical, and a positioning groove is opened. There are two cutting edges on the spherical surface. The cutting edges spiral upward on the conical surface. Spiral chip removal grooves are provided under the cutting edges. The spiral chip removal grooves are provided with edge cleaning, and ridges are provided on the edge cleaning; there is a step between the tool body and the tool shank, which is conical;

[0033] S2. Grinding and polishing: In this embodiment, the abrasive particle diameter of the abrasive flow polishing machine is 0.425 mm, the abrasive medium is SiC (silicon carbide), the initial working pressure is 4 MPa, the coolant is water, the grinding and polishing time is 20 min, and the initial feeding speed is 0.5 s / m. Among them, the setting of each parameter during the grinding and polishing process can be set by the implementer during actual application, and this embodiment does not make special restrictions on this.

[0034] During the grinding and polishing process, the temperature of the entire impeller is obtained by the semi-artificial thermocouple method; the flow rate of the abrasive in the grinding chamber is measured by an electromagnetic flowmeter. For data acquisition, in this embodiment, the data acquisition frequency is 10 Hz, and each 1 minute is taken as a time period. For the data collected in each time period, the temperatures at all acquisition moments within the time period are arranged in ascending order of time to form the temperature sequence of each time period. Correspondingly, the flow rate sequence is obtained. The calculation process of the semi-artificial thermocouple method is a well-known technology, and the specific calculation process will not be elaborated here.

[0035] Step 2: For each time period, the impeller temperature and the abrasive flow rate at all acquisition moments within the time period are respectively divided into subsequences to obtain each temperature subsequence and each flow rate subsequence; the temperature oscillation value of each temperature subsequence is obtained through the temperature change deviation situation in each temperature subsequence; in combination with the flow rate deviation situation in each flow rate subsequence and the temperature oscillation value of each temperature subsequence, the flow rate change degree of the abrasive flow polishing machine in each time period is obtained.

[0036] When the impeller is put into the abrasive flow polishing machine for grinding, as the abrasive in the grinding chamber continuously flows and forms a frictional force with the impeller surface, the frictional force will remove the material on the impeller surface, making the impeller surface smoother. Since friction generates heat, the temperature of the impeller surface will continuously increase. However, due to the different roughnesses of the surfaces of each blade of the impeller, the frictional forces between the abrasive and the blades are also different, resulting in the temperature rise on the impeller surface not being a straight line increase but having a non-linear characteristic.

[0037] During grinding, since the abrasive continuously frictions with the impeller surface to generate heat, the overall trend of the impeller temperature is continuously rising. In the early stage of grinding, due to the relatively large roughness of the impeller surface, the frictional force between the abrasive and the impeller is relatively large, so the impeller temperature rises relatively fast. As grinding progresses, the roughness of the impeller surface continuously decreases, and the frictional force between the abrasive and the impeller also continuously decreases, causing the temperature rise of the impeller to weaken, and within the same time, the rising temperature tends to the same value.

[0038] Based on the above analysis, for each time period, in this embodiment, the current time period is taken as an example for detailed description. Specifically, the temperature sequence of the current time period is evenly divided into N temperature subsequences. In this embodiment, N is taken as 20. Further, a straight line fitting is performed on the temperatures in the temperature subsequences to obtain a temperature straight line. Preferably, in this embodiment, the first temperature value and the last temperature value are used to obtain the temperature straight line through the two-point form equation of the straight line. According to the temperature change situation of the temperature straight line, the temperature oscillation value of each temperature subsequence is calculated. In this embodiment, the specific calculation formula is:

[0039] ; where, represents the temperature oscillation value of the i-th temperature subsequence; represents the number of temperatures in the temperature subsequence; represents the j-th temperature value in the i-th temperature subsequence; represents the value at the j-th position in the temperature straight line fitted from the i-th temperature subsequence; || represents the absolute value symbol.

[0040] In the early stage when the abrasive flow polishing machine grinds the integral impeller, due to the relatively high surface roughness of the integral impeller, the frictional force between the abrasive grains and the impeller surface is large. Since the roughness distribution on the impeller surface is uneven, the values of the temperature rise of the impeller within the same time are different. As a result, the difference between the impeller temperature and the temperature straight line increases, causing the temperature oscillation value of the impeller temperature subsequence to increase. It is necessary to increase the entry of the cooling material so that the cooling material can flow quickly and take away the heat on the impeller surface.

[0041] Furthermore, in the later stage of impeller grinding, due to the reduction of the impeller surface roughness, the frictional force value between the abrasive and the impeller decreases and tends to be stable. This situation will lead to a slowdown in the rate of temperature rise of the impeller. Without considering the cooling material taking away the heat of the impeller, the temperature rise within the same time tends to be stable. However, due to the continuous entry of the cooling material, the cooling material will take away the heat on the impeller surface. Therefore, the temperature oscillation value of the impeller at the same moment will approach 0.

[0042] Due to the friction between the abrasive and the impeller surface, the kinetic energy of the abrasive is converted into heat on the impeller surface, resulting in a reduction in the speed of the abrasive. In the early stage of grinding, due to the different roughnesses at various positions on the impeller surface, the change in the speed of the abrasive in the grinding chamber shows oscillation, and the relationship with the change in the impeller surface temperature decreases. In the later stage of grinding, the roughnesses at various positions on the impeller surface decrease and tend to the same value. Therefore, there is a strong correlation between the flow rate in the grinding intensity and the impeller surface temperature.

[0043] Based on the above analysis, the collected flow rate sequence of the grinding substance in the abrasive flow polishing machine is evenly divided into N subsequences, and then the mean absolute deviation of each flow rate subsequence is obtained. The mean absolute deviations of all flow rate subsequences corresponding to the current time period are sorted according to the positions of the flow rate subsequences to obtain the flow rate mean deviation sequence of the current time period, and the temperature oscillation values of all temperature subsequences corresponding to the current time period are sorted according to the positions of the temperature subsequences to obtain the temperature oscillation value sequence of the current time period.

[0044] Further, the temperature oscillation value sequence and the flow velocity mean deviation sequence are used as the inputs of the grey relational analysis algorithm, and the output is the correlation coefficient r between the temperature oscillation value sequence and the flow velocity mean deviation sequence. Thus, the flow velocity change degree of the abrasive flow polishing machine is calculated. In this embodiment, the specific calculation formula is:

[0045] ; where YV represents the flow velocity change degree of the abrasive flow polishing machine in the current time period; represents the mean value of all temperature oscillation values corresponding to the current time period; represents the mean value of the flow velocity mean deviation sequence; r represents the correlation coefficient between the temperature oscillation value sequence and the flow velocity mean deviation sequence; represents a constant to avoid a zero denominator, with a value range from 0 to 1. In this embodiment, the value is 0.1.

[0046] In the early stage of grinding the integral impeller, the surface roughness of the impeller is relatively high. During the grinding process of the impeller, the frictional force between the abrasive and the impeller surface is relatively large, and more heat energy is generated. Therefore, the mean value of all temperature oscillation values will be relatively large, and the flow velocity of the abrasive will decrease due to the frictional force, making the mean value of all elements in the flow velocity mean deviation sequence relatively large. Due to the different surface roughnesses of the impeller in the early stage, the temperature change of the impeller is relatively large, and the flow velocity change of the abrasive is relatively large. The relationship between the two parameters is relatively low; in the later stage of grinding, the smoothness of the impeller surface improves, the frictional force between the abrasive and the impeller surface decreases, and the magnitude of the frictional force is relatively stable. Therefore, the temperature on the impeller surface is relatively stable (with the cooling material taking away the heat), so the change in the flow velocity is also relatively stable. The correlation coefficient r between the two parameters is larger than that in the early stage of grinding. Therefore, the value of the flow velocity change degree YV of the abrasive flow polishing machine obtained in the early stage is relatively large, and the value of the flow velocity change degree YV in the later stage is relatively small. In order to grind the impeller more precisely, the pressure on the grinding machine is reduced, so that the grinding of the impeller can be carried out smoothly.

[0047] Step three: Fit the flow velocity change degrees of each time period, analyze the change trend of the flow velocity change degree, and combine the feeding speed of the abrasive flow polishing machine in the current time period to obtain the feeding adjustment speed of the abrasive flow polishing machine in the current time period, and adjust the feeding valve during the impeller grinding process.

[0048] During the grinding process of the whole, the surface roughness of the impeller continuously decreases. When the roughness is relatively low, the impeller should be ground with abrasive at a higher flow velocity, but it is necessary to prevent serious abrasive scratches on the impeller surface due to the too fast flow velocity of the abrasive, resulting in problems with the grinding quality of the impeller.

[0049] Under normal circumstances, the surface roughness of the impeller decreases with the progress of grinding time, and the flow rate of the abrasive flow polisher changes accordingly. The value of is decreasing, showing a downward trend. Therefore, in order to reduce the possibility of abrasive scratches on the impeller surface in the later stage, the grinding intensity pressure should be reduced, and the abrasive entry speed should also be continuously reduced over time.

[0050] Based on the above analysis, a straight line fit is performed on the flow velocity changes for the current time period and all previous time periods. In this embodiment, the flow velocity changes for the current time period and all previous time periods are used as inputs for the least squares method to obtain a fitted straight line. The slope of the fitted line is calculated and recorded as the trend slope for the current time period. Since only one time period exists in the first time period, no fitting can be performed. Therefore, the trend slope for the first time period is set to 0. The process of fitting a straight line using the least squares method is well known, and the specific calculation process is not repeated here.

[0051] Thus, the feed speed of the abrasive flow polisher is adjusted by changing the slope of different time periods. Based on the trend slope of each time period and the maximum value of the trend slope of each time period and multiple time periods before it, combined with the feed speed of the abrasive flow polisher in each time period, the feed adjustment speed of the abrasive flow polisher in the current time period is obtained. In this embodiment, the specific calculation formula is:

[0052] Where, Indicates the feed adjustment speed of the abrasive flow polisher in the current time period; The trend slope for the current time period; It represents the set of absolute values of trend slopes for the current time period and all previous time periods; represents the maximum value function; Indicates the feed rate of the abrasive flow polisher in the current time period. During grinding and polishing, the initial feed rate of the abrasive flow polisher in this embodiment is set to 0.5 m / s; Indicates a constant to prevent the denominator from being zero, with a value ranging from 0 to 1. In this embodiment, the value is 0.1.

[0053] As the abrasive flow polisher continuously grinds the entire impeller, the smoothness of the impeller surface improves. During the grinding process of the impeller, in order to prevent the abrasive from scratching the impeller surface, the pressure in the grinding chamber needs to be reduced. To adjust the pressure in the grinding chamber, it is necessary to adjust the entry rate of the abrasive. When grinding normally, the flow rate change of the abrasive flow polisher continues to decrease, and the value of the decrease continues to decrease, thereby making the trend slope of the abrasive flow polisher at different times negative, making the flow rate of the abrasive flow polisher at different time periods negative. The value is less than 1, so that the feeding adjustment speed of the abrasive flow polishing machine is relatively small, which can reduce the entry rate of the abrasive and perform more delicate grinding on the impeller.

[0054] Adjust the feeding port rate of the abrasive flow polishing machine according to the feeding adjustment speed and the actual feeding speed of the abrasive flow polishing machine in the current time period. By analyzing the feeding adjustment speed, the actual feeding rate, and the opening degree of the feeding valve in the current time period, accurately calculate the opening degree of the feeding valve after adjustment. In this embodiment, specifically, the calculation formula for the opening degree of the feeding valve after adjustment is:

[0055] ; In the formula, is the opening degree of the feeding valve after adjustment, is the opening degree of the feeding valve in the current time period, is the feeding speed of the abrasive flow polishing machine in the current time period, represents the feeding adjustment speed of the abrasive flow polishing machine in the current time period.

[0056] Adjust the feeding valve according to the obtained opening degree of the feeding valve, so as to realize the dynamic adjustment of the feeding speed. This proportional adjustment mechanism not only ensures the stability and consistency of the feeding speed, but also improves the response speed and flexibility of the entire grinding and polishing process.

[0057] It can be understood that referring to "one embodiment" or "some embodiments" described in the specification of this application means that specific features, structures, or characteristics described in connection with that embodiment are included in one or more embodiments of this application. Thus, if "in one embodiment", "in some embodiments", "in other some embodiments", "in still other embodiments", etc. appear in different places in this specification, they do not necessarily all refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "include", "comprise", "have" and their variants all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0058] It should be noted that the above sequence of the embodiments of this application is only for description and does not represent the superiority or inferiority of the embodiments. And the above specific embodiments of this specification have been described. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous. At the same time, the size of the serial numbers of the steps in the embodiments does not mean the sequence of execution. The execution sequence of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments in this specification.

[0059] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the various embodiments of the present application, and should all be included within the protection scope of the present application.

Claims

1. A grinding method for complex integral impellers, characterized in that, Including the following steps: Obtain the feeding speed of the abrasive flow polishing machine at each time period during the impeller grinding and polishing process, as well as the abrasive flow rate and impeller temperature at each acquisition moment within each time period; For each time period, perform subsequence division on the impeller temperature and abrasive flow rate at all acquisition moments within the time period to obtain each temperature subsequence and each flow rate subsequence; obtain the temperature oscillation value of each temperature subsequence through the temperature change deviation situation in each temperature subsequence; combine the flow rate deviation situation in each flow rate subsequence and the temperature oscillation value of each temperature subsequence to obtain the flow rate change degree of the abrasive flow polishing machine in each time period; Fit the flow rate change degrees of each time period, analyze the change trend of the flow rate change degree, and combine the feeding speed of the abrasive flow polishing machine in the current time period to obtain the feeding adjustment speed of the abrasive flow polishing machine in the current time period, and adjust the feeding valve during the impeller grinding process.

2. The grinding method for a complex integral impeller according to claim 1, characterized in that Each of the temperature subsequences further includes: the temperatures at all acquisition moments within each time period are arranged in ascending order of time to form the temperature sequence of each time period, and the temperature sequence is evenly divided into multiple subsequences, denoted as each temperature subsequence.

3. A grinding method for a complex integral impeller as described in claim 1, characterized in that Each of the flow rate subsequences further includes: the abrasive flow rates at all acquisition moments within each time period are arranged in ascending order of time to form the flow rate sequence of each time period, and the flow rate sequence is evenly divided into multiple subsequences, denoted as each flow rate subsequence.

4. A grinding method for a complex integral impeller according to claim 1, characterized in that, The expression for the temperature oscillation value of each temperature subsequence is: ; where, represents the temperature oscillation value of the i-th temperature subsequence; represents the number of temperatures in the temperature subsequence; represents the j-th temperature value in the i-th temperature subsequence; represents the value at the j-th position in the temperature straight line fitted from the i-th temperature subsequence; || represents the absolute value symbol.

5. A grinding method for a complex integral impeller according to claim 1, characterized in that, The expression for the flow rate change degree of the abrasive flow polishing machine in each time period is: ; where YV represents the flow velocity change degree of the abrasive flow polishing machine in the current time period; represents the mean value of all temperature oscillation values corresponding to the current time period; represents the mean value of the flow velocity mean deviation sequence; r represents the correlation coefficient between the temperature oscillation value sequence and the flow velocity mean deviation sequence; represents a constant to avoid a zero denominator.

6. A grinding method for a complex integral impeller according to claim 5, characterized in that The construction of the temperature oscillation value sequence further includes: sorting the temperature oscillation values of all temperature subsequences corresponding to the current time period according to the positions of the temperature subsequences to obtain the temperature oscillation value sequence of the current time period.

7. A grinding method for a complex integral impeller as claimed in claim 5, characterized in that, The construction of the flow rate average deviation sequence further includes: statistically calculating the average absolute deviation of each flow rate subsequence in each time period, and sorting the average absolute deviations of all flow rate subsequences in each time period according to the positions of the flow rate subsequences to obtain the flow rate average deviation sequence of each time period.

8. A grinding method for a complex integral impeller according to claim 1, characterized in that, The expression for the feeding adjustment speed of the abrasive flow polishing machine in the current time period is: ; wherein, represents the feed adjustment speed of the abrasive flow polishing machine in the current time period; the trend slope in the current time period; represents the set composed of the absolute values of the trend slopes in the current time period and all previous time periods; represents the maximum value function; represents the feed speed of the abrasive flow polishing machine in the current time period; represents a constant to avoid a zero denominator.

9. A grinding method for a complex integral impeller according to claim 8, characterized in that, The trend slope further includes: performing linear fitting on the flow rate change degrees of the current time period and all previous time periods, and denoting the straight line slope as the trend slope of the current time period, where the trend slope of the first time period is set to 0.

10. A grinding method for a complex integral impeller according to claim 1, characterized in that, The expression for the opening degree of the adjusted feed valve is as follows: ; In the formula, is the opening degree of the adjusted feed valve; is the opening degree of the feed valve in the current time period; is the feed rate of the abrasive flow polishing machine in the current time period; represents the feed adjustment rate of the abrasive flow polishing machine in the current time period.

Images