Grinding parameter compensation method for sand belt wear influence

Abstract

This invention provides a grinding parameter compensation method for the influence of abrasive belt wear, characterized by the following steps: Step 1: Establishing a grinding depth prediction model for planar abrasive belt grinding; Step 2: Calibrating the abrasive belt wear coefficient K. t The changing pattern; Step 3: Establish a grinding parameter compensation method with the goal of maintaining a constant grinding depth, based on the model in Step 1, with K t =1 Obtain the initial grinding parameters: belt linear velocity v s With feed rate v w The grinding parameter during the first Δt period is used to calculate the belt wear coefficient K at the end of the first Δt period. t The abrasion coefficient K obtained by this calculation t The grinding parameters for the second Δt period are reacquired, and this process is repeated iteratively until the expected grinding depth is obtained, and the grinding parameters corresponding to each Δt are output. This invention solves the problem of maintaining stable material removal due to wear in planar belt grinding, and can realize dynamic compensation of grinding parameters in the process of planar belt grinding. It has the characteristics of high compensation accuracy, short calculation time, and wide applicability.

Description

Technical Field

[0001] This invention belongs to the field of belt grinding technology and relates to a grinding parameter compensation method for wear problems in the process of planar belt grinding. Background Technology

[0002] Belt grinding is a finishing process that relies on the relative friction between high-hardness abrasive grains and the workpiece surface to remove material. The sharpness of the abrasive grains in the belt has a crucial impact on the material removal efficiency. However, as grinding time increases, the abrasive grains gradually wear down, including frictional wear, adhesive wear, and shedding wear, all of which ultimately result in a decrease in the belt's material removal capacity. When external factors such as the contact state between the belt and the workpiece and the grinding parameters remain constant, the material removal rate of belt grinding will decrease over time, gradually exceeding the expected dimensional and geometric tolerances. Therefore, dynamically compensating for changes in belt wear during belt grinding to maintain a relatively stable material removal rate is of great significance for improving the geometric accuracy of the workpiece.

[0003] Numerous factors influence the wear of abrasive belts. The degree of wear often exhibits a nonlinear relationship with variables such as material properties, contact pressure, belt linear speed, and working time. This poses a significant challenge to maintaining a stable grinding depth. Previous methods have not achieved accurate dynamic compensation of grinding parameters to address the impact of belt wear. Summary of the Invention

[0004] To address the aforementioned issues, this invention establishes a grinding depth prediction model for planar belt grinding by analyzing the grinding process. Combined with the variation law of belt wear coefficient calibrated by multi-factor wear experiments, a dynamic compensation method for grinding parameters in planar workpiece belt grinding is proposed to achieve stable control of grinding depth.

[0005] Specifically, this invention provides a grinding parameter compensation method for the influence of abrasive belt wear, characterized by the following steps: Step 1: Establishing a grinding depth prediction model for planar abrasive belt grinding.

[0006]

[0007] In equation (11), h is the expected grinding depth, r is the material removal depth per unit time at a point in the contact area (mm / s), P is the contact pressure at that point (MPa), and v s K represents the linear velocity of the abrasive belt, in m / s; K is a comprehensive constant related to factors such as workpiece material and abrasive belt type. t Let K be the abrasion coefficient of the abrasive belt, defined as varying within the range of (0,1]. For a new abrasive belt... t =1, the wear coefficient of the used sanding belt meets the condition 0 < K t <1;

[0008] Step 2: Calibrate the abrasion coefficient K of the sanding belt t The pattern of change

[0009]

[0010] In equation (12), t w The unit length working time of the abrasive belt represents the continuous service time of each point on the belt, measured in seconds (s). The base b1 is a number within the interval (0,1), and its magnitude directly reflects the wear rate of the abrasive belt, determined by factors such as contact pressure, belt linear velocity, workpiece material, and belt type. The unit length working time t of the abrasive belt... w Calculate according to the following formula:

[0011]

[0012] In formula (13), L is the circumference of the abrasive belt in mm; t is the total time for the abrasive belt to grind the workpiece in seconds; and l is the dimension of the contact area between the abrasive belt and the workpiece in the direction of the abrasive belt circumference in mm. For planar abrasive belt grinding, l is the width of the contact area 2b.

[0013] Step 3: Establish a grinding parameter compensation method with the goal of maintaining a constant grinding depth.

[0014] The time interval Δt for compensating grinding parameters is specified, based on the model in step one, with K... t =1 Obtain the initial grinding parameters: belt linear velocity v s With feed rate v w The grinding parameter during the first Δt period is used to calculate the belt wear coefficient K at the end of the first Δt period. t The abrasion coefficient K obtained from this calculation t Reacquire the grinding parameters during the second Δt period, and update the belt wear coefficient at the end of the second Δt period again. Repeat this iteration until the expected grinding depth is obtained, and output the grinding parameters corresponding to each Δt period.

[0015] Furthermore, in step two, the wear coefficient K of the abrasive belt is calibrated through a wear test. t The relationship between contact pressure, belt speed, and working time.

[0016] Furthermore, in step two, the value of b1 is calibrated through a wear test.

[0017] Furthermore, in step two, the wear test steps for calibrating b1 include:

[0018] S1: Determine the various combinations of contact pressure and abrasive belt linear velocity parameters used for abrasion, i.e., determine the abrasion parameters, as well as the contact pressure, abrasive belt linear velocity, and time interval used for calibrating the abrasion coefficient, i.e., determine the calibration parameters;

[0019] S2: Select a set of wear parameters from S1 to perform belt abrasion, and then conduct a calibration test under the calibration parameters to obtain the material removal rate r under the current combination of wear parameters. t Assuming no wear, if the material removal rate of this type of abrasive belt when grinding the same test bar under the same calibration parameters is r0, then the wear coefficient K of this abrasive belt at this time is... t for:

[0020]

[0021] By changing the wear duration and repeating the above steps, K can be obtained under the current wear parameters. t The relationship between K and wear duration is used to obtain K under the current wear parameters. t With t w The scatter plot is fitted to obtain the b1 value under the current wear parameters;

[0022] S3: Repeat S1 and S2 to obtain the b1 value under different combinations of wear parameters. Assume the wear coefficient of the abrasive belt at time t0 is... In [t] i ,t i+1 The value of b1 within the time period is b 1,i Working time per unit length (t) w For t w,i Then in [t n ,t n+1 Wear coefficient of the abrasive belt within a time period for:

[0023]

[0024] In equation (15), b 1,i It is based on the linear velocity v of the sander belt s The average pressure calculated by equation (9) is obtained by lookup or interpolation; t w,i It is calculated based on equations (6) and (13).

[0025] Furthermore, in step three, the function `Function` is called to calculate the grinding parameters. The inputs to `Function` include: the expected grinding depth `h` of the flat workpiece, the contact pressure `F` during grinding, and the current wear coefficient `K` of the abrasive belt. t The optimization range of the abrasive belt linear velocity is calculated by considering the constant K, coefficients b2 and b3, the radius R and width w of the abrasive belt, the Young's modulus E and Poisson's ratio ν of the abrasive belt. sd ,vsu , the optimized range of the feed speed [v wd , v wu , the decrement of the feed speed δ, the output of the function Function includes: the recommended belt speed v s and the feed speed v w , when the grinding contact pressure F, the belt wear coefficient K t , the comprehensive constant K, the coefficients b2, b3, the radius R and width w of the abrasive belt wheel, the Young's modulus E and Poisson's ratio ν of the abrasive belt wheel all meet the function input values, according to the belt speed v s and the feed speed v w for surface grinding, a stable grinding depth h can be obtained within a period of time.

[0026] Further, the function Function includes the following steps:

[0027] A1: After inputting the parameters, let v w = v wu ;

[0028] A2: Calculate the depth h w through v sd , calculate the depth h d through v w and v su ; u ;

[0029] A3: If h d < h < h u , then let v s = (v sd + v su ) / 2, calculate the depth h w through v s , enter step A4; otherwise let v m = v w - δ, enter step A5; w - δ, enter step A5;

[0030] A4: If |h m - h| < 0.05h, then output v w and v s , otherwise when h m < h let v sd = v s and return to step A3, when h m ≥ h let v su = v s and return to step A3;

[0031] A5: If h m < h then output no solution, otherwise return to step A3.

[0032] Furthermore, in step three, the iteration is repeated until the function has no solution during a certain Δt period, at which point the calculation is terminated and the grinding parameters corresponding to each Δt are output.

[0033] Furthermore, in the Function, the depth is calculated using equations (5) to (11):

[0034] The pressure distribution in the contact area during surface belt grinding is as follows:

[0035]

[0036] In equation (5), x is the radial distance from a point within the contact area to the contact center, and the width of the rectangular area is calculated according to the following formula:

[0037]

[0038] p0 is the maximum pressure within the contact area:

[0039]

[0040] E * It is the equivalent elastic modulus:

[0041]

[0042] In equation (8), E and ν are Young's modulus and Poisson's ratio of the abrasive belt pulley, respectively.

[0043] Average pressure P in the contact area ave for:

[0044]

[0045] When the abrasive belt wheel is at a feed speed v w When moving relative to the workpiece, the dwell time of each point on the workpiece surface within the contact area is... If we define the moment when a point just enters the contact region as t = 0, according to equation (5), the change law of the pressure P(t) of that point in the contact region with time t is expressed as:

[0046]

[0047] In a shorter time The wear coefficient K of the sander belt is considered to be... t Since it remains unchanged, combining equations (1) and (10), the grinding depth h of a certain point on the workpiece surface after the passing of the abrasive belt wheel is calculated according to the following formula:

[0048]

[0049] Equation (11) is called the grinding depth prediction model. In equation (11), K t The wear coefficient of the abrasive belt should be taken at a point on the workpiece surface before entering the contact area, i.e., at t=0.

[0050] Beneficial effects

[0051] This invention solves the problem of maintaining stable material removal due to wear in planar abrasive belt grinding by studying the relationship between grinding depth and various factors and combining it with quantitative analysis of abrasive belt wear. This invention enables dynamic compensation of grinding parameters during planar abrasive belt grinding, featuring high compensation accuracy, short calculation time, and wide applicability. Attached Figure Description

[0052] Figure 1 The contact between the abrasive belt wheel and the flat workpiece is shown.

[0053] Figure 2 K is a set of grinding parameters t With t w Relationship diagram.

[0054] Figure 3 The flowchart for calculating the recommended function for grinding parameters is shown.

[0055] Figure 4 This is a flowchart of a dynamic compensation method for grinding parameters. Detailed Implementation

[0056] This invention addresses the problem of reduced material removal capacity caused by abrasive belt wear. It provides a grinding parameter compensation method for maintaining a constant grinding depth. The specific embodiments of this invention will be further described in detail below with reference to the accompanying drawings.

[0057] This invention first combines the traditional material removal rate model and elastic contact model of belt grinding to obtain a grinding depth prediction model for planar belt grinding through integration. Then, through calibration experiments (wear experiments), the complex relationship between the belt wear coefficient and factors such as contact pressure, belt linear velocity, and working time is determined, achieving accurate prediction of the wear state. Subsequently, based on the grinding depth prediction model, a set of grinding parameter recommendation functions is established with the goal of achieving the expected grinding depth. Finally, the change in the wear coefficient is introduced into the grinding depth prediction model, and it iterates with the predicted wear state. By continuously updating the current wear state and calculating new grinding parameters, a dynamic compensation method for grinding parameters is established with the goal of maintaining a constant grinding depth, thereby realizing dynamic compensation of grinding parameters in the planar belt grinding process.

[0058] The first step of this invention is to calculate the grinding parameters for each time interval, and the second step is to calculate the wear state of the abrasive belt for each time interval.

[0059] Step 1: Establish a grinding depth prediction model for surface belt grinding

[0060] In the contact area between the abrasive belt and the material being ground, the material removal efficiency can be calculated using the following formula, which is called the material removal rate model for abrasive belt grinding:

[0061]

[0062] In equation (1): r is the material removal depth per unit time at a point within the contact area, in mm / s; P is the contact pressure at that point, in MPa; v s K represents the linear velocity of the abrasive belt, in m / s; K is a comprehensive constant related to factors such as workpiece material and abrasive belt type; K t The wear coefficient of the abrasive belt is defined as its range of variation as (0,1]. The K value of a new abrasive belt... t =1, the wear coefficient of the used sanding belt meets the condition 0 < K t <1. Normally, r is related to P and v. s All are positively correlated.

[0063] Once the type of abrasive belt and the material of the workpiece are determined, the coefficients b2, b3 and K in equation (1) need to be calibrated through experiments.

[0064] The test blocks were ground under different combinations of contact pressure and belt linear velocity, and the height change of the test blocks was measured after the same time. The material removal rate r was calculated based on the height change ΔH of the test block within the grinding time Δt. The calculation formula is as follows:

[0065]

[0066] The grinding experiment design is shown in Table 1, and the calculated material removal rate r is recorded in Table 1. As a control variable, each grinding operation requires the use of a new, unused abrasive belt of the same type. Therefore, K... t =1, and the grinding time Δt must remain the same.

[0067] Table 1. Material removal rate determination under different grinding parameters.

[0068]

[0069] Taking the logarithm of both sides of equation (1), let y = lg(r), b0 = lg(K), x2 = lg(P), x3 = lg(v) s If ), then the expression becomes:

[0070] y = b0 + b2x2 + b3x3 (3)

[0071] Let x be the independent variable of the i-th experiment. i,2 ,xi,3 The experimental results are denoted as y. i ,make

[0072]

[0073] Based on least squares estimation, the estimated values ​​of parameters b0, b2, and b3 are... The calculation can be performed using the following formula:

[0074]

[0075] According to the Hertzian contact model, when an elastic abrasive belt wheel with radius R and width w comes into contact with a rigid plane under grinding pressure F, the contact area is a rectangle with length w and width 2b, and the center of the rectangular contact area is also the location of the current contact point. Figure 1 This illustrates the contact between the abrasive belt wheel and the flat workpiece, such as... Figure 1 As shown, if the direction of relative feed is defined as the x-axis, the pressure distribution in the contact area on the x-axis is semi-elliptical, and the pressure does not change in the direction perpendicular to the x-axis.

[0076] According to the Hertzian contact model, the pressure distribution in the contact area during surface belt grinding is as follows:

[0077]

[0078] In equation (5), x is the radial distance from a point within the contact area to the contact center, and the width of the rectangular area can be calculated using the following formula:

[0079]

[0080] p0 is the maximum pressure within the contact area:

[0081]

[0082] E * It is the equivalent elastic modulus:

[0083]

[0084] In equation (8), E and ν are Young's modulus and Poisson's ratio of the abrasive belt pulley, respectively.

[0085] Average pressure P in the contact area ave for:

[0086]

[0087] When the abrasive belt wheel is at a feed speed v w When moving relative to the workpiece, the dwell time of each point on the workpiece surface within the contact area is... If we define the moment when a point just enters the contact region as t = 0, according to equation (5), the change law of the pressure P(t) of that point in the contact region with time t can be expressed as:

[0088]

[0089] In a shorter time Within this range, the wear coefficient K of the abrasive belt can be considered as... t Since the grinding depth h of a certain point on the workpiece surface after the passing of the abrasive belt wheel remains unchanged, combining equations (1) and (10), the grinding depth h can be calculated according to the following formula:

[0090]

[0091] Equation (11) is called the grinding depth prediction model. Note that in equation (11), K t The wear coefficient of the abrasive belt should be taken at a point on the workpiece surface before entering the contact area (at time t=0).

[0092] Step 2: Calibrate the abrasion coefficient K of the sanding belt t The pattern of change

[0093] Abrasion coefficient K of sanding belt t It is a real number in the interval (0,1], and its change can be represented by an exponential function:

[0094]

[0095] In equation (12), t w This refers to the working time per unit length of the sanding belt, representing the continuous service time at various points on the sanding belt, measured in seconds (s). The working time per unit length of the sanding belt is t. w It can be calculated using the following formula:

[0096]

[0097] In equation (13), L is the circumference of the abrasive belt in mm; t is the total time for the abrasive belt to grind the workpiece in seconds; and l is the dimension of the contact area between the abrasive belt and the workpiece along the circumference of the abrasive belt in mm. For planar abrasive belt grinding, l is the width of the contact area, 2b.

[0098] In equation (12), K t It is monotonically decreasing in (0,1], t w It is a positive number. According to the properties of the exponential function, the base b1 is a number in the interval (0,1). The magnitude of b1 directly represents the rate of abrasive belt wear, which is determined by factors such as contact pressure, abrasive belt linear velocity, workpiece material, and abrasive belt type.

[0099] In practical applications, the value of b1 needs to be calibrated beforehand through wear tests. The wear test for b1 calibration consists of two parts: the abrasive belt wear process under given parameters and the abrasive belt wear coefficient calibration process. The purpose of conducting the wear process is to obtain abrasive belts under different wear states.

[0100] Calculate the wear coefficient K of the sander belt t First, b1 needs to be calibrated. The calibration process of b1 is divided into two steps: the abrasive belt wear process under different wear parameter combinations and wear durations, and the material removal rate calibration process under the calibration parameter combination.

[0101] Taking workpiece material #45, abrasive material white corundum, and abrasive belt grit size #150 as an example, the specific steps for the wear test to calibrate b1 are as follows:

[0102] S1: Determine the various combinations of contact pressure and belt linear velocity parameters used for abrasive belts, i.e., determine the abrasion parameters, and determine the contact pressure, belt linear velocity, and time interval used for calibrating the abrasion coefficient, i.e., determine the calibration parameters.

[0103] Determining the parameters for the abrasive belt wear process and the abrasive belt wear coefficient calibration process involves first determining the wear parameters and calibration parameters. For example, the wear parameters are: the contact pressure during the abrasive belt wear process is selected as 0.1 MPa, 0.2 MPa, and 0.3 MPa, and the abrasive belt linear velocity is selected as 10 m / s, 20 m / s, and 30 m / s; the calibration parameters are: the contact pressure for calibrating the wear coefficient is selected as 0.2 MPa, the abrasive belt linear velocity for calibrating the wear coefficient is selected as 20 m / s, and the time interval for calibrating the wear coefficient is selected as 100 s, forming the 9 sets of experiments shown in Table 2.

[0104] Table 2. Wear coefficient calibration experiments under different grinding parameters.

[0105]

[0106]

[0107] S2: Select a set of wear parameters from S1 to perform belt abrasion, and then conduct a calibration test under the calibration parameters to obtain the material removal rate r under the current combination of wear parameters. t .

[0108] Several cubic test bars with a side length of 10 mm were prepared from 45# steel. K was calibrated under the nine conditions listed in Table 2. t The changing pattern.

[0109] Taking the first group of experiments as an example, a new abrasive belt was taken, and the abrasive belt linear speed was controlled at 10 m / s to make the test bar contact the abrasive belt. The contact pressure was controlled to be uniformly distributed and 0.1 MPa. After grinding for 100 s, under the parameters of abrasive belt linear speed of 20 m / s and contact pressure of 0.2 MPa, the material removal rate r of the same test bar ground by the abrasive belt at this time was calculated according to formula (2). t (That is, the material removal rate r is calculated based on the change in the height of the specimen during the grinding time).

[0110] Assuming that the material removal rate of this type of abrasive belt when grinding the same test bar under the same calibration parameters is r0 before wear, then the wear coefficient K of this abrasive belt at this time is... t for:

[0111]

[0112] By changing the wear duration and repeating the above steps, K can be obtained under the current wear parameters. t The relationship between K and wear duration is used to obtain K under the current wear parameters. t With t w The scatter plot is used to obtain the b1 value under the current wear parameters through fitting.

[0113] Following the method described above, the wear coefficient of the abrasive belt after continuous grinding for 200s, 300s, and 400s can be determined, thus yielding K. t Based on the relationship between the wear parameters and the grinding time, and using equations (12) and (13), we can obtain K under the first set of wear parameters. t With t w Scatter plot. Figure 2 K is a set of grinding parameters t With t w A relationship diagram. For example... Figure 2 As shown, by fitting, the b1 value under the first set of wear parameters is obtained.

[0114] S3: Repeat S1 and S2 to obtain the b1 value under different combinations of wear parameters. Assume the wear coefficient of the abrasive belt at time t0 is... In [t] i ,t i+1 The value of b1 within the time period is b 1,i During this time period, b1 depends on the recommended grinding parameters at that time, and the working time t per unit length. w For t w,i Then in [t n ,t n+1 Wear coefficient of the abrasive belt within a time period for:

[0115]

[0116] Repeat the calibration method described above to obtain the b1 values ​​under different combinations of grinding parameters, and fill the results into Table 3.

[0117] Table 3 b1 values ​​under different grinding parameter combinations

[0118]

[0119] Assume the wear coefficient of the abrasive belt at time t0 is In [t] i ,t i+1 The value of b1 within the time period is b 1,i During this time period, b1 depends on the recommended grinding parameters at that time, and the working time t per unit length. w For t w,i Then in [t n ,t n+1 Wear coefficient of the abrasive belt within a time period for:

[0120]

[0121] In equation (15), b 1,i It is based on the linear velocity v of the sander belt s The average pressure calculated by equation (9) is obtained by looking up or interpolating from Table 3; t w,i It is calculated based on equations (6) and (13).

[0122] In actual grinding, the pressure distribution in the contact area between the abrasive belt and the workpiece is uneven at every instant. Here, the average pressure calculated using equation (9) is used to approximate the contact pressure in the wear parameters. The value of b1 for each parameter combination is obtained by fitting a curve, i.e. Figure 2 The process. Table 3 records b1 under some parameter combinations, but it is impossible to obtain b1 for every parameter. For example, b1 for linear speeds of 10 and 20 has been fitted. If you want to know b1 for linear speed of 15, you can only interpolate based on adjacent b1. The more wear tests you do, the smaller the interpolation error will be.

[0123] Step 3:

[0124] After completing steps one and two, a grinding parameter recommendation function can be constructed. The inputs to this function include: the expected grinding depth h of the flat workpiece, the grinding contact pressure F, and the current wear coefficient K of the abrasive belt. t The comprehensive constant K, coefficients b2 and b3 determined in step one, the radius R and width w of the abrasive belt, the Young's modulus E and Poisson's ratio ν of the abrasive belt, and the optimized range of the abrasive belt linear velocity [v] sd ,v su ], the optimal range of feed rate [vwd , v wu , the decrement δ of the feed rate. The output of the function Function includes: the recommended abrasive belt linear speed v s and the feed rate v w .

[0125] Grinding according to the recommended parameters can obtain the expected grinding depth h under the input parameter conditions.

[0126] The function Function includes the following steps:

[0127] A1: After inputting the parameters, let v w = v wu ;

[0128] A2: Calculate the depth h w through v sd and v d , and calculate the depth h w through v su and v u ;

[0129] A3: If h d < h < h u , then let v s = (v sd + v su ) / 2, calculate the depth h w through v s , and enter step A4; otherwise let v m = v w - δ, and enter step A5; w - δ, and enter step A5;

[0130] A4: If |h m - h| < 0.05h, then output v w and v s , otherwise when h m < h, let v sd = v s and return to step A3, when h m ≥ h, let v su = v s and return to step A3.

[0131] A5: If h m < h, then output no solution, otherwise return to step A3.

[0132] In the function Function, the depth is calculated by equations (5) to (10).

[0133] When the grinding contact pressure F, the abrasive belt wear coefficient K tWhen the constant K, coefficients b2 and b3, belt radius R, width w, Young's modulus E, and Poisson's ratio ν of the belt all conform to the function input values, the belt linear velocity v output by the function will be calculated. s and feed rate v w By performing surface grinding, a stable grinding depth h can be obtained over a period of time.

[0134] It should be noted that the calculation results of the Function do not take into account the decrease in the abrasive belt wear coefficient and are only accurate within a short grinding time. Figure 3 The flowchart shows the calculation process for the recommended function (Function) for grinding parameters. The specific implementation steps of the function (Function) are as follows: Figure 3 .like Figure 3 As shown,

[0135] Once the grinding parameter recommendation function is obtained, a dynamic compensation method for grinding parameters during the belt grinding process can be constructed. Figure 4 The flowchart shows the dynamic compensation method for grinding parameters. Figure 4 As shown, the characteristic of the dynamic compensation method for grinding parameters to address the impact of abrasive belt wear lies in calibrating the abrasive belt wear coefficient K through wear experiments. t The relationship between the grinding parameters and factors such as contact pressure, belt speed, and working time is defined. The time interval Δt for compensating grinding parameters is specified. The Function is called to calculate the recommended grinding parameters for the first Δt period. Based on the calculated grinding parameters and Table 2 and Equation (15), the wear coefficient of the belt at the end of the first Δt is calculated. The new belt wear coefficient is substituted into the second Δt, and the Function is called again to calculate the recommended grinding parameters for the second Δt period. The belt wear coefficient at the end of the second Δt is updated again. This process is repeated iteratively until the expected grinding depth is obtained. That is, it is iterated until a certain calculation cannot be solved within the parameter range, which means that the wear has become unusable and the removal depth cannot be met. Specifically, this process is repeated iteratively until the Function has no solution for a certain Δt period. The calculation can then be terminated, and the grinding parameters corresponding to each Δt are output (i.e., Table 4). The grinding parameters are dynamically adjusted during the grinding process according to the output results, which can compensate for the decrease in material removal capacity caused by belt wear, thereby ensuring a constant grinding depth.

[0136] The method ultimately outputs the linear velocity v of the sanding belt. s With feed rate v w The changes over time t are shown in Table 4 (the values ​​in the table are examples). By dynamically adjusting the parameters during the grinding process according to the values ​​given in Table 4, the decrease in material removal capacity caused by belt wear can be compensated, thereby ensuring a constant grinding depth.

[0137] Table 4 Grinding parameters calculated using the compensation method

[0138]

[0139] It should be noted that the above description is merely illustrative and explanatory of the present invention. Those skilled in the art should understand that any modifications and substitutions to the present invention fall within the scope of protection of the present invention.

Claims

1. A grinding parameter compensation method against the influence of abrasive belt wear, characterized by, The method comprises the following steps: Step one: establishing a grinding depth prediction model of flat belt grinding （11） In formula (11), is the expected grinding depth, is the material removal depth per unit time at a certain point in the contact area, with units of mm / s; is the contact pressure at the point, with units of MPa; is the belt linear speed, with units of m / s; is a comprehensive constant related to the workpiece material and the type of belt; is the belt wear coefficient, defined to vary in the range (0, 1], with the new belt wear coefficient being , and the worn belt wear coefficient satisfying , is a coefficient; Step two: Calibration of the sanding belt wear coefficient of the change law （12） In formula (12) is the unit length working time of the abrasive belt, which represents the continuous service time of each point on the abrasive belt, and the unit is s; the base is a number in the interval (0, 1), The size of intuitively represents the rate of abrasive belt wear, which is determined by factors such as contact pressure, abrasive belt linear speed, workpiece material, and abrasive belt type; the unit length working time of the abrasive belt is calculated according to the following formula: （13） L is the length of the belt, in mm; L is the length of the belt, in mm; L is the length of the belt, in mm; L is the length of the belt, in mm; L is the length of the belt, in mm; L is the length of the belt, in mm; Step three: establishing a grinding parameter compensation method with the goal of maintaining constant grinding depth Specify the time interval for compensating grinding parameters Based on the model in step one, with Obtain initial grinding parameters: belt linear velocity With feed rate As the first The grinding parameters during the period, and the first calculation based on these parameters. At the end, the sanding belt wear coefficient The abrasion coefficient of the sander belt obtained by this calculation Reacquire the second one The grinding parameters during the process were updated again for the second time. The abrasion coefficient at the end is calculated, and this process is repeated iteratively until the desired grinding depth is obtained, and each result is output. The corresponding grinding parameters, In step three, a function Function is called to calculate the grinding parameters, the input of the function Function includes: the expected grinding depth of the plane workpiece , the contact pressure during grinding , the current wear coefficient of the abrasive belt , the comprehensive constant , the coefficient , the radius of the abrasive belt wheel , the width , the Young's modulus of the abrasive belt wheel , the Poisson's ratio , the optimization range of the abrasive belt linear velocity , the optimization range of the feed speed , the decrement of the feed speed , the output of the function Function includes: the recommended abrasive belt linear velocity and the feed speed , when the grinding contact pressure , the abrasive belt wear coefficient , the comprehensive constant , the coefficient , the abrasive belt wheel radius , the width , the Young's modulus of the abrasive belt wheel , the Poisson's ratio all meet the function input values, the plane grinding is carried out according to the abrasive belt linear velocity and the feed speed output by the function, and a stable grinding depth is obtained within a period of time ; In the function Function, the depth is calculated by equations (5)-(11): The contact pressure distribution in the contact area of flat belt grinding is: （5） In formula (5), The width of the rectangular area is calculated according to the following formula: （6） is the maximum pressure in the contact area: （7） is the equivalent elastic modulus: （8） In equation (8) and These are Young's modulus and Poisson's ratio of the abrasive belt wheel, respectively. Average pressure in the contact area Is: （9） When the abrasive belt wheel is at the feed speed When moving relative to the workpiece, the dwell time of each point on the workpiece surface within the contact area is... If the moment when a point just enters the contact region is defined as... According to equation (5), the pressure at this point in the contact area varies with time. The pattern of change Expressed as: （10） In the contact area between the belt and the material to be ground, the material removal efficiency is calculated according to the following formula, which is called the material removal rate model of belt grinding: （1） In a shorter time The wear coefficient of the sanding belt is considered to be... Since it remains unchanged, combining equations (1) and (10), the grinding depth of a certain point on the workpiece surface after the abrasive belt wheel has passed is... Calculate according to the following formula: （11） The equation (11) is called a grinding depth prediction model, in the equation (11), The abrasive belt wear coefficient value at the time when the workpiece surface point enters the contact area before = 0.

2. The grinding parameter compensation method for the influence of abrasive belt wear according to claim 1, characterized by, In step two, the abrasive belt wear coefficient is calibrated by the wear experiment The relationship between the contact pressure, the abrasive belt linear speed, and the working time.

3. The grinding parameter compensation method for the influence of abrasive belt wear according to claim 1, characterized by, In step two, the values of the number of revolutions to failure are determined by the wear test .

4. The grinding parameter compensation method for the influence of abrasive belt wear according to claim 3, characterized by, In step two, the calibration The wear test step comprises: S1: determining a plurality of contact pressure and belt linear velocity parameter combinations for the worn belt, i.e., determining the wear parameters, and determining the contact pressure, belt linear velocity, and time interval for calibrating the wear coefficient, i.e., determining the calibration parameters; S2: select a set of wear parameters for belt wear, and then conduct a calibration test under the calibration parameters to obtain the material removal rate under the current wear parameter combination , assuming that the material removal rate of the same kind of test bar is , under the same calibration parameters, the wear coefficient of the belt at this time is: （14） Change the wear time, repeat the above steps, that is, the current wear parameters under The relationship with the wear time, the current wear parameters under With Scatter plot, by fitting the current wear parameters under the Value; S3: Repeat S1 and S2 to obtain the results under different combinations of wear parameters. Value, assuming the sand belt is The wear coefficient at time is ,exist within the time period Value Working time per unit length for Then in Wear coefficient of sanding belt over a period of time for: （15） In formula (15), is calculated according to the belt linear velocity and the average pressure calculated by formula (9), obtained by looking up or interpolating; calculated according to formula (6) and formula (13).

5. The grinding parameter compensation method for the effect of abrasive belt wear according to Claim 1, characterized by, The function Function comprises the following steps: A1: After inputting the parameters, let = ;​ A2: by and computing depth by and computing depth ; A3: if then let = ( + ) / 2, compute depth by and , go to A4; otherwise let = - , go to A5;​​ A4: if , then output and , otherwise at < , let = and return to step A3, at ≥ , let = and return to step A3; A5: If then output no solution, otherwise go to step A3.​ 6. The grinding parameter compensation method for the influence of abrasive belt wear according to claim 5, characterized by, In step three, the iteration is repeated until a certain one The function Function during the period has no solution, i.e. the calculation is terminated, and the respective Grinding parameters are output.

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