A method for online monitoring and evaluation of superhard material grinding wheel performance

Abstract

The present invention discloses an online monitoring and evaluation method for the performance of a superhard material grinding wheel, comprising the following steps: establishing an online monitoring system platform for the wear resistance of a grinding wheel in the outer cylindrical processing step in the superhard material grinding wheel manufacturing process, calculating the wear ratio by an indirect measurement method of the outer diameter D of the tool grinding wheel, introducing a dressing coefficient correction, and obtaining the batch wear ratio. The present invention combines the measurement of the wear ratio with further parameter dressing, thereby enabling data judgment and risk warning of the wear resistance and processing life of the batch-produced grinding wheel, and can remind the product of the hidden dangers of life fluctuations. Through risk response measures, the phenomenon of large fluctuations in life reaching the required critical value at the application terminal can be effectively avoided. At the same time, the product manufacturing process can be traced and audited through monitoring data, providing a judgment basis for improving the quality stability of the product in the manufacturing link.

Description

Technical Field

[0001] The invention relates to the technical field of superhard material processing, and in particular to an online monitoring and evaluation method for superhard material grinding wheel performance. Background Art

[0002] At present, superhard grinding wheels refer to abrasives made of diamond or cubic boron nitride as abrasives, metal, resin or ceramic materials as binders and different types of fillers, prepared by special processes such as physical or chemical methods; they can be used for different types of mechanical processing such as grinding, lapping, polishing or cutting, and have production characteristics such as multiple varieties, small batches and customization, and have very high requirements for precision, process and quality stability. Application areas include: national defense, aerospace, electronic chips, photovoltaics, automobile manufacturing, tool manufacturing, etc., and have the title of "industrial teeth".

[0003] The manufacturing process of superhard material grinding wheels generally includes process flows such as compounding, matrix processing, compression molding, sintering and curing, plane processing, inner hole processing, outer circle processing, and quality inspection. The performance requirements of this type of product include: strength, rigidity, sharpness, wear resistance, processing quality and processing life, etc. Among them, processing life refers to the amount of material removed by the grinding wheel from the beginning of grinding to the consumption of the limit size. Commonly used units: volume, weight, number of pieces, length, etc., are product indicators that end customers focus on, and the length of processing life is mainly reflected in the wear resistance of the abrasive layer of the superhard material grinding wheel. At present, for finished grinding wheels, the conventional quality inspection process generally only involves geometric dimension inspection such as product appearance, dimensional tolerance or form and position tolerance, and does not have the inspection capabilities and evaluation methods for intrinsic performance. Therefore, the wear resistance and cutting life of the grinding wheel cannot be effectively tested and evaluated.

[0004] There are many factors that affect the wear resistance of grinding wheels, including raw material quality, abrasive layer formula design, molding process, mold loss, curing and sintering process, post-processing shape and dimensional accuracy, etc. For the processing life of grinding wheels, in addition to the factors affecting the wear resistance of grinding wheels, it also includes aspects such as the workpiece material, machine tool performance, grinding process, cooling effect, etc. at the end user's site. Due to the lack of effective detection or monitoring methods, it is impossible to evaluate and determine the wear resistance before the product is shipped, and it is impossible to assess whether the end user's processing life meets the standards.

[0005] Therefore, if an online monitoring system for the wear resistance of grinding wheels can be established to monitor batch abnormalities in real time during the manufacturing process, and to classify and grade them for use, as well as to detect, isolate and dispose of them early, it will be possible to prevent problematic products from flowing out, and change from passive cooperation and improvement after problems occur to active monitoring and prevention, thereby improving product quality stability. Summary of the invention

[0006] The purpose of the present invention is to provide an online monitoring and evaluation method for the performance of superhard material grinding wheels, which can monitor the wear resistance of batch-produced superhard material grinding wheels, determine the fluctuation range and provide risk warning, meet the requirements of the end-user life indicators, and provide a judgment basis for improving the quality stability of grinding wheels in the manufacturing process. The above problems have been solved, and the wear resistance of different batches of superhard material grinding wheels can be monitored, thereby effectively evaluating the processing life of the product terminal application site.

[0007] The technical solution adopted by the present invention is:

[0008] A method for online monitoring and evaluation of superhard material grinding wheel performance comprises the following steps:

[0009] Step A: Establishing an online monitoring system platform for grinding wheel wear resistance in the cylindrical machining process of superhard material grinding wheel manufacturing process, wherein the online monitoring platform comprises a CNC cylindrical grinder, a tool grinding wheel, a product grinding wheel, an active measuring instrument, a data interface and a monitoring computer, wherein the tool grinding wheel and the product grinding wheel are respectively arranged on a grinding wheel frame and a workbench, wherein the computer controls the CNC cylindrical grinder to drive the tool grinding wheel and the product grinding wheel to grind, and the active measuring instrument is used to monitor the diameter of the product grinding wheel and send the data to the monitoring computer through the data interface;

[0010] Step B: Calculate the volume wear ratio g; Specifically, expand the calculation formula, extract the direct measurement value, and then calculate the characteristic value of the wear resistance evaluation of the superhard material grinding wheel, that is, the volume wear ratio g;

[0011] v = π (r1 2 -r2 2 )t=π(d1 2 -d2 2 )t / 4=π(d1+d2)(d1-d2)t / 4;

[0012] The calculation formula of tool grinding wheel loss volume is expanded: V=π(R1 2 -R2 2 )T=π(D1 2 -D2 2 )T / 4=π(D1+D2)(D1-D2)T / 4;

[0013] In actual experiments, the calculation process is as follows: V=π(X1+657.873-d1+X2+657.873-d2)(X1+657.873-d1-X2-657.873+d2)T / 4, V=π(1315.746+X1+X2-d1-d2)(X1-X2-d1+d2)T / 4.

[0014] Among them, v is the loss volume of the product grinding wheel, V is the loss volume of the tool grinding wheel, d1 is the initial diameter of the product grinding wheel, r1 is the initial radius of the product grinding wheel; r2 is the radius of the product grinding wheel after grinding, X1 is the initial machine tool coordinate value of the tool grinding wheel, d2 is the diameter of the product grinding wheel after grinding, X2 is the machine tool coordinate value of the tool grinding wheel after grinding, t is the thickness of the product grinding wheel group, T is the thickness of the tool grinding wheel, D1 is the initial diameter of the tool grinding wheel, R1 is the initial radius of the tool grinding wheel; R2 is the radius of the tool grinding wheel after grinding, and D2 is the diameter of the product tool grinding wheel after grinding; the diameter D of the tool grinding wheel is obtained by indirect measurement, d1 and d2 are measured by the active measuring instrument installed on the CNC cylindrical grinder and automatically transmitted to the monitoring system computer; X1 and X2 are extracted by the machine tool control system and transmitted to the monitoring system computer through the data interface; t and T are manually measured by the wireless data transmission micrometer and transmitted to the monitoring system computer. The final calculation formula is: g=V 工具砂轮 / V 产品砂轮 =V / v;

[0015] Step C: Introduce the tool grinding wheel correction factor to correct the system error caused by the difference in wear resistance of different tool grinding wheels:

[0016] The correction coefficient of the tool grinding wheel is determined by grinding with a standard grinding wheel. The standard grinding wheel is made of superhard material. The manufacturing process fixes all production factors such as machine, material, method, and environment measurement and is completed in a short time. In this way, it can be approximately considered that there is no wear resistance fluctuation of the standard grinding wheel. When the first tool grinding wheel is used, it is first ground with the standard grinding wheel. The volume wear ratio G1 of the two is obtained by the above method. When the second tool grinding wheel is used, G2 is obtained. By analogy, G3, G4, G5...G n The correction coefficient of the tool grinding wheel is recorded as M. The calculation formula of the correction coefficient of the first tool grinding wheel is: M1=G1 / G1, the correction coefficient formula of the second tool grinding wheel is: M2=G2 / G1, the correction coefficient of the third tool grinding wheel is recorded as: M3=G3 / G1, and so on. The correction coefficients of all tool grinding wheels can be obtained;

[0017] Step D: Collect data on the grinding wheels of the batch to be monitored:

[0018] Solidify the external cylindrical machining process parameters, grind the products to be monitored, group and number the grinding wheels of the products in the monitoring batch, and then grind them with the tool grinding wheel in turn, and then collect the grinding data. Collect k groups of monitoring data for each batch, and calculate the volume wear ratios g1, g2, ..., g k , the CNC external cylindrical machining process parameters that need to be fixed include: spindle tool grinding wheel speed, product grinding wheel speed, reciprocating distance, reciprocating speed, single-pass feed amount, and product grinding wheel quantity;

[0019] The calculated volume wear ratio g is divided by the correction coefficient M of the tool grinding wheel corresponding to the monitoring data to obtain the volume wear ratio after the first correction, which is recorded as: g 修正1 =g / M, k groups of data are recorded as: g 1修正1 , g 2修正1 ……g k修正1 ;

[0020] Step E: Introduce the compensation coefficient N of the tool grinding wheel outer diameter and the product grinding wheel outer diameter data to correct the system error caused by the numerical difference between the different initial outer diameters D1 of the same tool grinding wheel and the different diameter sections d1 and d2 of the product grinding wheel;

[0021] Specifically, all monitoring data of tool grinding wheel grinding g 1修正1 , g 2修正1 ……g k修正1 According to the three factors of D1, d1, and d2, a multivariate regression analysis is performed to obtain the regression equation, Y=F(x)=a*D1+b*d1+c*d2+e, where a, b, and c are equation coefficients, and e is the equation constant; suppose that after this correction, the monitoring data is equivalent to the wear ratio when the outer diameter of the tool grinding wheel is D1' and the outer diameter of the product grinding wheel is d1' and d2', where D1', d1', and d2' are all fixed values; the calculation formula for the correction compensation coefficient N is:

[0022] N = F (D1', d1', d2') - F (D1, d1, d2) = a* (D1'-D1) + b* (d1'-d1) + c* (d2'-d2), the volume wear ratio g calculated in step D 修正1 Add the correction compensation coefficient N, recorded as: g 修正2 ,but:

[0023] g 修正2 =g 修正1 +N,k groups of data are recorded as: g 1修正2 , g 2修正2 ……g k修2 ;

[0024] Step F: Calculate the batch average volume wear ratio `g 修正2 , as the characteristic value of wear resistance of this production batch;

[0025] The average volume wear ratio of batch n is recorded as: `g 修正2 (Pn), the average volume wear ratio calculation formula of batch 1 is:

[0026] `g 修正2 (P1) = (g 1修正2 +g 2修正2 ……g k修正2 ) / k, and so on, calculate `g 修正2 (P2), `g修正2 (P3) ... 修正2 (Pn);

[0027] Step G: Output the batch average volume wear ratio SPC control chart according to the wear resistance characteristic value of the batch obtained in step F, and make a steady-state judgment on the wear resistance data of the product grinding wheel according to the 9 abnormal data judgment criteria;

[0028] Step H: After long-term implementation, the batch average volume wear ratio of the first Q batches of the SPC control chart under steady-state control

[0029] `g 修正2 (Pn), and then calculate the average value as the wear resistance index of the grinding wheel of this model product, recorded as S, then:

[0030] S=(`g 修正2 (P1)+`g 修正2 (P2)+……+`g 修正2 (PQ)) / Q;

[0031] Step I: Based on the S value, calculate the upper and lower control limits of the monitoring index of the wear resistance fluctuation of the product grinding wheel batch of ±10%, ±20%, and ±30%. Based on this, calculate the wear resistance fluctuation range of each subsequent production batch. By comparing the two, it can be determined whether the wear resistance of the product grinding wheel batch to be monitored meets the requirements.

[0032] The indirect measurement method of the outer diameter D of the tool grinding wheel is as follows:

[0033] From the relationship between the tool grinding wheel, product grinding wheel and machine tool coordinates in the CNC external cylindrical grinder grinding, it can be known that: R+r=xy; D+d=2x-2y=XY; Y=XDd, and X=2x, Y=2y, since D and d can be obtained by measuring a set of data, and X can be extracted from the machine tool control system, the Y value can be obtained by measuring a set of data: Y=XDd, and since the Y value of the same CNC external cylindrical grinder is a fixed value, after the Y value is determined, the second and subsequent data can be reversed by the formula D=XYd and the X value and d value to obtain the tool grinding wheel diameter D value: R is the tool grinding wheel radius, D is the tool grinding wheel diameter, r is the product grinding wheel radius, d is the product grinding wheel diameter, x is the tool grinding wheel coordinate value, X is the tool grinding wheel machine tool coordinate value, y is the product grinding wheel coordinate value, and Y is the product grinding wheel machine tool coordinate value.

[0034] The k value is: k≥3.

[0035] It also includes the following step J, which establishes the risk level of product grinding wheel batch wear resistance fluctuation, response procedures, risk reminder records, end-user life feedback records and closed-loop management measures for problem handling based on the S value according to actual control requirements.

[0036] The Q value is: Q≥15.

[0037] The present invention introduces an online monitoring system for the wear resistance of superhard material grinding wheels to monitor the wear ratio of the grinding wheels in real time, then performs parameter adjustment on the monitored wear ratio, and then performs data judgment and risk warning on the wear resistance and processing life of batch-produced grinding wheels through the wear ratio of batches, which can remind the product of the hidden danger of life fluctuation, and effectively avoid the phenomenon of large fluctuations in life reaching the required critical value at the application terminal through risk response measures, and also can trace and audit the product manufacturing process through monitoring data, so as to provide a judgment basis for improving the quality stability of products in the manufacturing link. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 is a flow chart of the present invention;

[0040] Figure 2 This is a structural principle diagram of the grinding wheel wear resistance online monitoring system platform of the present invention;

[0041] Figure 3 This is a coordinate relationship diagram of the external cylindrical CNC grinding tool grinding wheel, product grinding wheel and machine tool described in the present invention. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] like Figure 1 , 2 As shown in 3, the present invention comprises the following steps:

[0044] Step A: Establishing an online monitoring system platform for grinding wheel wear resistance in the cylindrical machining process of superhard material grinding wheel manufacturing process, wherein the online monitoring platform comprises a CNC cylindrical grinder, a tool grinding wheel, a product grinding wheel, an active measuring instrument, a data interface and a monitoring computer, wherein the tool grinding wheel and the product grinding wheel are respectively arranged on a grinding wheel frame and a workbench, wherein the computer controls the CNC cylindrical grinder to drive the tool grinding wheel and the product grinding wheel to grind, and the active measuring instrument is used to monitor the diameter of the product grinding wheel and send the data to the monitoring computer through the data interface;

[0045] Step B: Calculate the volume wear ratio g; Specifically, expand the calculation formula, extract the direct measurement value, and then calculate the characteristic value of the wear resistance evaluation of the superhard material grinding wheel, that is, the volume wear ratio g;

[0046] The formula for calculating the loss volume of the product grinding wheel is expanded as follows: v=π(r1 2 -r2 2 )t=π(d1 2 -d2 2 )t / 4=π(d1+d2)(d1-d2)t / 4;

[0047] The calculation formula of tool grinding wheel loss volume is expanded: V=π(R1 2 -R2 2 )T=π(D1 2 -D2 2 )T / 4=π(D1+D2)(D1-D2)T / 4;

[0048] In actual experiments, the calculation process is as follows: V=π(X1+657.873-d1+X2+657.873-d2)(X1+657.873-d1-X2-657.873+d2)T / 4, V=π(1315.746+X1+X2-d1-d2)(X1-X2-d1+d2)T / 4.

[0049] Among them, v is the loss volume of the product grinding wheel, V is the loss volume of the tool grinding wheel, d1 is the initial diameter of the product grinding wheel, r1 is the initial radius of the product grinding wheel; r2 is the radius of the product grinding wheel after grinding, X1 is the initial machine tool coordinate value of the tool grinding wheel, d2 is the diameter of the product grinding wheel after grinding, X2 is the machine tool coordinate value of the tool grinding wheel after grinding, t is the thickness of the product grinding wheel group, T is the thickness of the tool grinding wheel, D1 is the initial diameter of the tool grinding wheel, R1 is the initial radius of the tool grinding wheel; R2 is the radius of the tool grinding wheel after grinding, and D2 is the diameter of the product tool grinding wheel after grinding; the diameter D of the tool grinding wheel is obtained by indirect measurement, d1 and d2 are measured by the active measuring instrument installed on the CNC cylindrical grinder and automatically transmitted to the monitoring system computer; X1 and X2 are extracted by the machine tool control system and transmitted to the monitoring system computer through the data interface; t and T are manually measured by the wireless data transmission micrometer and transmitted to the monitoring system computer. The final calculation formula is: g=V 工具砂轮 / V 产品砂轮 =V / v;

[0050] Step C: Introduce the tool grinding wheel correction factor to correct the system error caused by the difference in wear resistance of different tool grinding wheels:

[0051] The correction coefficient of the tool grinding wheel is determined by grinding with a standard grinding wheel. The standard grinding wheel is made of superhard material. The manufacturing process fixes all production factors such as machine, material, method, and environment measurement and is completed in a short time. In this way, it can be approximately considered that there is no wear resistance fluctuation of the standard grinding wheel. When the first tool grinding wheel is used, it is first ground with the standard grinding wheel. The volume wear ratio G1 of the two is obtained by the above method. When the second tool grinding wheel is used, G2 is obtained. By analogy, G3, G4, G5...G n The correction coefficient of the tool grinding wheel is recorded as M. The calculation formula of the correction coefficient of the first tool grinding wheel is: M1=G1 / G1, the correction coefficient formula of the second tool grinding wheel is: M2=G2 / G1, the correction coefficient of the third tool grinding wheel is recorded as: M3=G3 / G1, and so on. The correction coefficients of all tool grinding wheels can be obtained;

[0052] Step D: Collect data on the grinding wheels of the batch to be monitored:

[0053] Solidify the external cylindrical machining process parameters, grind the products to be monitored, group and number the grinding wheels of the products in the monitoring batch, and then grind them with the tool grinding wheel in turn, and then collect the grinding data. Collect k groups of monitoring data for each batch, and calculate the volume wear ratios g1, g2, ..., g k , the CNC external cylindrical machining process parameters that need to be fixed include: spindle tool grinding wheel speed, product grinding wheel speed, reciprocating distance, reciprocating speed, single-pass feed amount, and product grinding wheel quantity;

[0054] The calculated volume wear ratio g is divided by the correction coefficient M of the tool grinding wheel corresponding to the monitoring data to obtain the volume wear ratio after the first correction, which is recorded as: g 修正1 =g / M, k groups of data are recorded as: g 1修正1 , g 2修正1 ……g k修正1 ;

[0055] Step E: Introduce the compensation coefficient N of the tool grinding wheel outer diameter and the product grinding wheel outer diameter data to correct the system error caused by the numerical difference between the different initial outer diameters D1 of the same tool grinding wheel and the different diameter sections d1 and d2 of the product grinding wheel;

[0056] Specifically, all monitoring data of tool grinding wheel grinding g 1修正1 , g 2修正1 ……g k修正1 According to the three factors of D1, d1, and d2, a multivariate regression analysis is performed to obtain the regression equation, Y=F(x)=a*D1+b*d1+c*d2+e, where a, b, and c are equation coefficients, and e is the equation constant; suppose that after this correction, the monitoring data is equivalent to the wear ratio when the outer diameter of the tool grinding wheel is D1' and the outer diameter of the product grinding wheel is d1' and d2', where D1', d1', and d2' are all fixed values; the calculation formula for the correction compensation coefficient N is:

[0057] N = F (D1', d1', d2') - F (D1, d1, d2) = a* (D1'-D1) + b* (d1'-d1) + c* (d2'-d2), the volume wear ratio g calculated in step D 修正1 Add the correction compensation coefficient N, recorded as: g 修正2 ,but:

[0058] g 修正2 =g 修正1 +N,k groups of data are recorded as: g 1修正2 , g 2修正2 ……g k修2 ;

[0059] Step F: Calculate the batch average volume wear ratio `g 修正2 , as the characteristic value of wear resistance of this production batch;

[0060] The average volume wear ratio of batch n is recorded as: `g 修正2 (Pn), the average volume wear ratio calculation formula of batch 1 is:

[0061] `g 修正2 (P1) = (g 1修正2 +g 2修正2 ……g k修正2 ) / k, and so on, calculate `g 修正2 (P2), `g修正2 (P3) ... 修正2 (Pn);

[0062] Step G: Output the batch average volume wear ratio SPC control chart according to the wear resistance characteristic value of the batch obtained in step F, and make a steady-state judgment on the wear resistance data of the product grinding wheel according to the 9 abnormal data judgment criteria;

[0063] Step H: After long-term implementation, the batch average volume wear ratio of the first Q batches of the SPC control chart under steady-state control

[0064] `g 修正2 (Pn), and then calculate the average value as the wear resistance index of the grinding wheel of this model product, recorded as S, then:

[0065] S=(`g 修正2 (P1)+`g 修正2 (P2)+……+`g 修正2 (PQ)) / Q;

[0066] Step I: Based on the S value, calculate the upper and lower control limits of the monitoring index of the wear resistance fluctuation of the product grinding wheel batch of ±10%, ±20%, and ±30%. Based on this, calculate the wear resistance fluctuation range of each subsequent production batch. By comparing the two, it can be determined whether the wear resistance of the product grinding wheel batch to be monitored meets the requirements.

[0067] The indirect measurement method of the outer diameter D of the tool grinding wheel is as follows:

[0068] From the relationship between the tool grinding wheel, product grinding wheel and machine tool coordinates in the CNC external cylindrical grinder, it can be known that: R+r=xy; and X=2x, Y=2y, so D+d=2x-2y=XY; Y=XDd, since D and d can be obtained by measuring a set of data, and X can be extracted from the machine tool control system, the Y value can be obtained by measuring a set of data: Y=XDd, and since the Y value of the same CNC external cylindrical grinder is a fixed value, after the Y value is determined, the second and subsequent data can be reversed by the formula D=XYd and the X value and d value to obtain the tool grinding wheel diameter D value: R is the tool grinding wheel radius, D is the tool grinding wheel diameter, r is the product grinding wheel radius, d is the product grinding wheel diameter, x is the tool grinding wheel coordinate value, X is the tool grinding wheel machine tool coordinate value, y is the product grinding wheel coordinate value, and Y is the product grinding wheel machine tool coordinate value. By indirectly measuring the outer diameter D of the grinding wheel, the efficiency of measurement can be greatly improved, and the accuracy is also very high, which provides a strong guarantee for subsequent monitoring. Specifically, according to the attached Figure 3From the relationship diagram of the external cylindrical CNC grinding tool grinding wheel, product grinding wheel and machine tool coordinates, we can see that: R+r=xy ⇒ D+d=2x-2y=XY ⇒ Y=XDd. Since D and d can be obtained by measuring a set of data, and X can be extracted from the machine tool control system, the Y value can be obtained by measuring a set of data: Y=XDd=-657.873 (the Y value of different CNC external cylindrical grinders is different and is a fixed value). After the Y value is determined, the second and subsequent data can be used to reversely calculate the tool grinding wheel diameter D value through the formula D=XYd and the X value and d value: D=XYd=X+657.873-d. In this way, the outer diameter D of the tool grinding wheel can be indirectly measured, and the measurement results are concise and efficient, and the data is reliable, with an error of ≤0.01.

[0069] The monitoring data k value is K≥3. When k is less than 3 groups, the sample size of the monitoring data is small, which is not representative enough for the overall (batch to be monitored) data and may cause relatively large sampling errors. In principle, the larger the k value is, the more sufficient the sampling data is, and the more reliable the monitoring value finally obtained is. Generally speaking, when 3≤k≤10, it can meet the actual needs.

[0070] It also includes the following step J, which establishes the risk level of product grinding wheel batch wear resistance fluctuation, response procedures, risk reminder records, end-user life feedback records and closed-loop management measures for problem handling based on the S value according to actual control requirements.

[0071] The batch number Q selected in the SPC control chart under steady-state control is ≥15. When Q<15, the normality of the monitoring data may be insufficient, thereby affecting the accuracy of the calculated value of the product grinding wheel wear resistance index S. In practical applications, the Q value range is generally 15-25.

[0072] The present invention provides an online monitoring system and evaluation method for the wear resistance of a superhard material grinding wheel. Figure 2 As shown, the online monitoring system is installed in the external cylindrical processing process of superhard material grinding wheels, and is composed of a CNC external cylindrical grinder, a workbench 1, a product grinding wheel 2, a tool grinding wheel 3, a CNC grinder control system 4, a data interface 5, an active diameter gauge 8, a wireless data transmission micrometer 7 and a monitoring computer 6. Among them, the CNC external cylindrical grinder control program adopts a fixed processing technology, the workbench processing process provides reciprocating motion, the tool grinding wheel and the product grinding wheel are fed in opposite directions for grinding processing, the CNC grinder control system transmits the machine tool coordinate value to the monitoring computer through the data interface, the active diameter gauge transmits the product grinding wheel outer diameter value to the monitoring computer through the data interface, and the tool grinding wheel and product grinding wheel thickness values ​​are transmitted to the monitoring computer through the wireless data transmission micrometer. After the computer summarizes the data, it calculates the wear resistance evaluation characteristic value-volume wear ratio g 修正2。The following is an explanation based on a specific case, assuming that the batch number of the monitored grinding wheel is 26:

[0073] Step 1: prepare a set of standard grinding wheels, install the tool grinding wheel and the standard grinding wheel on the CNC cylindrical grinder, grind both according to fixed process parameters, collect machine tool coordinate data X1, X2, product grinding wheel outer diameter values ​​d1 and d2, and tool grinding wheel thickness value T and product grinding wheel thickness value t, and transmit them to the monitoring computer. According to the method in step C of the specific implementation method, the monitoring computer automatically outputs the tool grinding wheel correction coefficient M.

[0074] Step 2: Prepare 5 groups of product grinding wheels and install them on CNC cylindrical grinders respectively. Grind them according to fixed process parameters. Collect machine coordinate data X1, X2, product grinding wheel outer diameter values ​​d1 and d2, tool grinding wheel thickness value T and product grinding wheel thickness value t respectively, and transmit them to the monitoring computer. According to the method in step D of the specific implementation method, the monitoring computer automatically outputs 5 groups of volume wear ratios g1, g2, g3, g4 and g5.

[0075] Step 3: According to the formula: g 修正1 = g / M, automatically output by the monitoring computer 1修正1 , g 2修正1 ……g 5修正1 .

[0076] Step 4: Calculate the correction compensation coefficient N using statistical analysis software according to the method described in step E of the specific implementation method.

[0077] According to the formula: g 修正2 =g 修正1 +N, automatically output by the monitoring computer g 1修正2 , g 2修正2 ……g 5修2 .

[0078] Step 5: Calculate the batch average volume wear ratio g according to the method described in step F of the specific implementation method. 修正2 (Pn), as the wear resistance characteristic value of the grinding wheel of this batch of products, `g 修正2 (P26) = (g 1修正2 +g 2修正2 +g 3修正2 +g 4修正2 +g 5修正2 ) / 5.

[0079] Step 6: Based on the data obtained in step 5 and combined with previous historical data, output the batch average volume wear ratio `g 修正2 The SPC control chart of (Pn) is used to determine the steady-state of the product grinding wheel wear resistance data based on 9 abnormal data determination criteria.

[0080] Step 7: According to the method described in step H of the specific implementation method, the batch average volume wear ratio of the first 25 batches in the SPC control chart under the steady-state control state is calculated based on historical data. 修正2 (Pn), and then calculate the average value as the wear resistance index of the grinding wheel of this model product, recorded as S, S= (`g 修正2 (P1)+`g 修正2 (P2)+……+`g 修正2 (P25)) / 25.

[0081] Step 8: Compare the S value and the average volume wear ratio of this batch `g 修正2 (P26), calculate the fluctuation range, recorded as S%

[0082] Then, S%=(`g 修正2 (P26) -S) / S*100%, compare S% with the upper and lower limit requirements to determine whether the wear resistance of the grinding wheel of this batch of products meets the requirements.

[0083] Step 9: Based on actual control requirements, establish closed-loop management measures for product grinding wheel batch wear resistance fluctuation risk levels, response procedures, risk reminder records, end-user life feedback records, and problem handling.

[0084] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

[0085] In the description of the present invention, it should be noted that directional words, such as the terms "center", "lateral", "longitudinal", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like, indicating directions and positional relationships based on the directions or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and cannot be understood as limiting the specific protection scope of the present invention.

[0086] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0087] Note that the above are only preferred embodiments of the present invention and the principles of the application technology. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention is described in more detail through the above embodiments, the present invention is not limited to the specific embodiments described herein, and may include more other effective embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A method for online monitoring and evaluation of superhard material grinding wheel performance, characterized in that: The steps include: Step A: Establishing an online monitoring system platform for grinding wheel wear resistance in the external cylindrical processing step of the superhard material grinding wheel process, wherein the online monitoring system platform comprises a CNC external cylindrical grinder, a tool grinding wheel, a product grinding wheel, an active measuring instrument, a data interface and a monitoring computer, wherein the tool grinding wheel and the product grinding wheel are respectively arranged on a grinding wheel frame and a workbench, and the monitoring computer controls the CNC external cylindrical grinder to drive the tool grinding wheel and the product grinding wheel to grind, and the active measuring instrument is used to monitor the diameter of the product grinding wheel and send it to the monitoring computer through the data interface; Step B: Calculate the volume wear ratio g; Specifically, expand the calculation formula, extract the direct measurement value, and then calculate the characteristic value of the wear resistance evaluation of the superhard material grinding wheel, that is, the volume wear ratio g; The formula for calculating the loss volume of the product grinding wheel is expanded as follows: v=π(r1 2 -r2 2 )t=π(d1 2 -d2 2 )t / 4=π(d1+d2)(d1-d2)t / 4; The calculation formula of tool grinding wheel loss volume is expanded: V=π(R1 2 -R2 2 )T=π(D1 2 -D2 2 )T / 4=π(D1+D2)(D1-D2)T / 4 Among them, v is the loss volume of the product grinding wheel, V is the loss volume of the tool grinding wheel, d1 is the initial diameter of the product grinding wheel, r1 is the initial radius of the product grinding wheel; r2 is the radius of the product grinding wheel after grinding, X1 is the initial machine tool coordinate value of the tool grinding wheel, d2 is the diameter of the product grinding wheel after grinding, X2 is the machine tool coordinate value of the tool grinding wheel after grinding, t is the thickness of the product grinding wheel group, T is the thickness of the tool grinding wheel, D1 is the initial diameter of the tool grinding wheel, R1 is the initial radius of the tool grinding wheel; R2 is the radius of the tool grinding wheel after grinding, and D2 is the diameter of the tool grinding wheel after grinding; the diameter D of the tool grinding wheel is obtained by indirect measurement, d1 and d2 are measured by the active measuring instrument installed on the CNC external cylindrical grinder and automatically transmitted to the monitoring system computer; X1 and X2 are extracted by the machine tool control system and transmitted to the monitoring system computer through the data interface; t and T are manually measured by the wireless data transmission micrometer and transmitted to the monitoring system computer. The final calculation formula is: g=V 工具砂轮 / V 产品砂轮 =V / v; Step C: Introduce the tool grinding wheel correction factor to correct the system error caused by the difference in wear resistance of different tool grinding wheels: The correction coefficient of the tool grinding wheel is determined by grinding with a standard grinding wheel. The standard grinding wheel is made of superhard material. The manufacturing process fixes all the production factors of man-machine, material-method, environment and measurement and is completed in a short time. In this way, it can be approximately considered that there is no wear resistance fluctuation of the standard grinding wheel. When the first tool grinding wheel is used, it is first ground with the standard grinding wheel. The volume wear ratio G1 of the two is obtained by the above method. When the second tool grinding wheel is used, G2 is obtained. By analogy, G3, G4, G5...G n The correction coefficient of the tool grinding wheel is recorded as M. The calculation formula of the correction coefficient of the first tool grinding wheel is: M1=G1 / G1, the correction coefficient formula of the second tool grinding wheel is: M2=G2 / G1, the correction coefficient of the third tool grinding wheel is recorded as: M3=G3 / G1, and so on. The correction coefficients of all tool grinding wheels can be obtained; Step D: Collect data on the grinding wheels of the batch to be monitored: Solidify the external cylindrical machining process parameters, grind the products to be monitored, group and number the grinding wheels of the products in the monitoring batch, and then grind them with the tool grinding wheel in turn, and then collect the grinding data. Collect k groups of monitoring data for each batch, and calculate the volume wear ratios g1, g2, ..., g k , the CNC external cylindrical machining process parameters that need to be fixed include: spindle tool grinding wheel speed, product grinding wheel speed, reciprocating distance, reciprocating speed, single-pass feed amount, and product grinding wheel quantity; The calculated volume wear ratio g is divided by the correction coefficient M of the tool grinding wheel corresponding to the monitoring data to obtain the volume wear ratio after the first correction, which is recorded as: g 修正1 =g / M, k groups of data are recorded as: g 1修正1 , g 2修正1 ……g k修正1 ; Step E: Introduce the compensation coefficient N of the tool grinding wheel outer diameter and the product grinding wheel outer diameter data to correct the system error caused by the numerical difference between the different initial outer diameters D1 of the same tool grinding wheel and the different diameter sections d1 and d2 of the product grinding wheel; Specifically, all monitoring data of tool grinding wheel grinding g 1修正1 , g 2修正1 ……g k修正1 According to the three factors of D1, d1, and d2, a multivariate regression analysis is performed to obtain the regression equation, Y=F(x)=a*D1+b*d1+c*d2+e, where a, b, and c are equation coefficients, and e is the equation constant; suppose that after this correction, the monitoring data is equivalent to the wear ratio when the outer diameter of the tool grinding wheel is D1' and the outer diameter of the product grinding wheel is d1' and d2', where D1', d1', and d2' are all fixed values; the calculation formula for the correction compensation coefficient N is: N = F (D1', d1', d2') - F (D1, d1, d2) = a* (D1'-D1) + b* (d1'-d1) + c* (d2'-d2), the volume wear ratio g calculated in step D 修正1 Add the correction compensation coefficient N, recorded as: g 修正2 ,but: g 修正2 =g 修正1 +N,k groups of data are recorded as: g 1修正2 , g 2修正2 ……g k修2 ; Step F: Calculate the batch average volume wear ratio `g 修正2 , as the wear resistance characteristic value of the current batch; The average volume wear ratio of batch n is recorded as: `g 修正2 (Pn), the average volume wear ratio calculation formula of batch 1 is: `g 修正2 (P1) = (g 1修正2 +g 2修正2 ……g k修正2 ) / k, and so on, calculate `g 修正2 (P2), `g 修正2 (P3) ... 修正2 (Pn); Step G: Output the batch average volume wear ratio SPC control chart according to the wear resistance characteristic value of the batch obtained in step F, and make a steady-state judgment on the wear resistance data of the product grinding wheel according to the 9 abnormal data judgment criteria; Step H: After long-term implementation, the batch average volume wear ratio of the first Q batches of the SPC control chart under steady-state control is `g 修正2 (Pn), and then calculate the average value as the wear resistance index of the grinding wheel of this model product, recorded as S, then: S=(`g 修正2 (P1)+`g 修正2 (P2)+……+`g 修正2 (PQ)) / Q; Step I: Based on the S value, calculate the upper and lower control limits of the monitoring index of the wear resistance fluctuation of the product grinding wheel batch of ±10%, ±20%, and ±30%. Based on this, calculate the wear resistance fluctuation range of each subsequent production batch. By comparing the two, it can be determined whether the wear resistance of the product grinding wheel batch to be monitored meets the requirements.

2. The method for online monitoring and evaluation of superhard material grinding wheel performance according to claim 1, characterized in that: The indirect measurement method of the outer diameter D of the tool grinding wheel is as follows: From the relationship between the tool grinding wheel, product grinding wheel and machine tool coordinates in the CNC external cylindrical grinder grinding, it can be known that: R+r=xy; D+d=2x-2y=XY; Y=XDd, and X=2x, Y=2y, since D and d can be obtained by measuring a set of data, and X can be extracted from the machine tool control system, the Y value can be obtained by measuring a set of data: Y=XDd, and since the Y value of the same CNC external cylindrical grinder is a fixed value, after the Y value is determined, the second and subsequent data can be reversed by the formula D=XYd and the X value and d value to obtain the tool grinding wheel diameter D value: R is the tool grinding wheel radius, D is the tool grinding wheel diameter, r is the product grinding wheel radius, d is the product grinding wheel diameter, x is the tool grinding wheel coordinate value, X is the tool grinding wheel machine tool coordinate value, y is the product grinding wheel coordinate value, and Y is the product grinding wheel machine tool coordinate value.

3. The method for online monitoring and evaluation of superhard material grinding wheel performance according to claim 2, characterized in that: The k value is: k≥3.

4. The method for online monitoring and evaluation of superhard material grinding wheel performance according to claim 2, characterized in that: It also includes the following step J, which establishes the risk level of product grinding wheel batch wear resistance fluctuation, response procedures, risk reminder records, end-user life feedback records and closed-loop management measures for problem handling based on the S value according to actual control requirements.

5. The method for online monitoring and evaluation of superhard material grinding wheel performance according to claim 3 is characterized in that: The Q value is: Q≥15.

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