Prediction method, device and terminal for circumferential waviness of a part machined by external cylindrical grinding

Abstract

The application relates to the technical field of machining processes, and discloses a prediction method and device for circumferential waviness of an outer circle grinding machining part and a terminal, the method comprising the following steps: acquiring a grinding wheel parameter and a workpiece parameter during outer circle grinding machining; acquiring a machining motion parameter during outer circle grinding machining; calculating a circumferential waviness amplitude value of the outer circle grinding part based on the grinding wheel parameter, the workpiece parameter and the machining motion parameter; obtaining a function of the circumferential waviness profile in a polar coordinate system; and obtaining the circumferential waviness profile based on the function. The grinding wheel parameter, the workpiece parameter and the machining motion parameter during outer circle grinding are acquired, the amplitude value is calculated by using an amplitude calculation coefficient, the profile function is calculated by using a profile calculation coefficient, the functions of predicting the grinding waviness profile and the amplitude value of the workpiece before grinding machining are realized, and theoretical basis is provided for pre-judging whether the machining precision of the part is qualified and for optimizing suitable machining process parameters.

Description

Technical Field

[0001] This invention relates to the field of machining technology, specifically to a method, apparatus, and terminal for predicting the circumferential waviness of parts processed by external cylindrical grinding. Background Technology

[0002] Among the many machining processes, grinding is often considered a decisive process in forming critical dimensions and surfaces. This process particularly determines the key precision indicators of parts. For high-precision rotating parts, their dimensional accuracy, geometric accuracy, and surface quality largely depend on external cylindrical grinding.

[0003] Surface waviness describes the irregularity of a surface, consisting of random or approximately periodic components much larger than surface roughness. This accuracy index lies in the frequency range between surface roughness and shape accuracy. During cylindrical grinding, vibrations of the machine tool, workpiece, and grinding wheel system are the primary cause of periodic undulations around the part's circumference. By definition, the amplitude of a single wave refers to the radius difference between adjacent peaks and valleys on the circumferential waviness profile; while the amplitude of circumferential waviness refers to the average of the five largest amplitudes across a cross-section.

[0004] Circumferential waviness has a significant impact on the performance and service life of rotating parts. For example, surface waviness errors in optical components affect image quality. If the surface waviness amplitude of a bearing raceway is reduced from 2.5 micrometers to 0.5 micrometers, its service life can more than double. It is worth noting that waviness errors generated during external cylindrical grinding are difficult to completely eliminate even in subsequent fine machining. Therefore, controlling the waviness amplitude during the grinding process is crucial. Predicting the potential circumferential waviness and amplitude after grinding, and selecting appropriate grinding parameters accordingly, is of great value for practical production.

[0005] Literature review reveals that current research on surface waviness in grinding primarily focuses on vibration analysis of grinding systems. These studies are largely theoretical, and due to the difficulty in measuring the vibration characteristics of machine tools, their practical guidance for operators is limited. Summary of the Invention

[0006] The technical problem to be solved by this invention is how to effectively predict the circumferential waviness profile and amplitude value of parts processed by external cylindrical grinding. The purpose is to provide a method, device and terminal for predicting the circumferential waviness of parts processed by external cylindrical grinding, taking into account adjustable processing parameters and grinding wheel and workpiece parameters, and making the prediction method and process simple, clear and easy to operate.

[0007] This invention is achieved through the following technical solution:

[0008] A method for predicting the circumferential waviness of parts machined by external cylindrical grinding includes:

[0009] Obtain the grinding wheel parameters and workpiece parameters during external cylindrical grinding.

[0010] Obtain the machining motion parameters during external cylindrical grinding;

[0011] Calculate the circumferential waviness amplitude value of the external cylindrical grinding part based on the grinding wheel parameters, workpiece parameters, and machining motion parameters;

[0012] Obtain the function of the circumferential waviness profile in polar coordinates;

[0013] The circumferential ripple profile is obtained by drawing based on functions.

[0014] Optionally, the grinding wheel parameters include: grinding wheel radius r g Grinding wheel width B g Grinding wheel circular runout error e r ;

[0015] The workpiece parameters include: workpiece radius r w ;

[0016] The machining motion parameters include: workpiece rotation speed N. w Grinding wheel speed N g Feed rate V f Grinding depth a p .

[0017] Optionally, the circumferential waviness amplitude value W of the external cylindrical grinding part z The calculation formula is: C1 and C2 are amplitude calculation coefficients.

[0018] The functional expression R(β) of the circumferential waviness profile in polar coordinates is:

[0019] R(β)=r w +W z ·(1-sin(π(C3β-floor(C3β)))), where 0≤β≤2π, C3 is the contour calculation coefficient, β is the angle in the polar coordinate system, and floor() is the integer function that takes the largest integer less than or equal to the value.

[0020] Optionally, the formula for calculating the amplitude calculation coefficient C1 is as follows:

[0021] The formula for calculating the amplitude calculation factor C2 is as follows:

[0022] The formula for calculating the profile calculation factor C3 is as follows:

[0023] Where, Nwc T is the critical speed of the workpiece. θ denoted as the wave shift value of the grinding wheel-workpiece speed ratio, and n as the grinding width ratio;

[0024] Specifically, the critical speed N of the workpiece wc The calculation formula is:

[0025] The wave shift value T of the grinding wheel-workpiece speed ratio θ The calculation formula is:

[0026] The formula for calculating the grinding width ratio n is:

[0027] Where, round() is the integer rounding function that takes the nearest integer value, B f This refers to the grinding width.

[0028] Optionally, the grinding wheel circular runout error is obtained by measuring it during actual grinding rotation using a non-contact method.

[0029] Alternatively, the circumferential waviness profile is obtained by inputting the function expression R(β) into mathematical plotting software.

[0030] A device for predicting the circumferential waviness of parts processed by external cylindrical grinding includes:

[0031] The parameter acquisition module is used to acquire the grinding wheel parameters and workpiece parameters during external cylindrical grinding; it is also used to acquire the machining motion parameters during external cylindrical grinding.

[0032] The amplitude calculation module is used to calculate the circumferential waviness amplitude of external cylindrical grinding parts based on grinding wheel parameters, workpiece parameters, and machining motion parameters.

[0033] The profile function module is used to obtain the function of the circumferential waviness profile in polar coordinates.

[0034] The contour drawing module is used to draw circular ripple contours based on functions.

[0035] A terminal for predicting the circumferential waviness of a cylindrically ground part includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the method for predicting the circumferential waviness of a cylindrically ground part as described above.

[0036] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0037] This invention obtains the grinding wheel parameters, workpiece parameters, and machining motion parameters during external cylindrical grinding, and calculates the wave amplitude value using the amplitude calculation coefficient and the contour function using the contour calculation coefficient. It enables the prediction of the workpiece grinding waviness profile and wave amplitude value before grinding, providing a theoretical basis for predicting whether the part machining accuracy is qualified and for selecting appropriate machining process parameters. Attached Figure Description

[0038] The accompanying drawings illustrate exemplary embodiments of the present invention and, together with the description thereof, serve to explain the principles of the invention. These drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, but do not constitute a limitation on the embodiments of the present invention.

[0039] Figure 1 This is a flowchart illustrating a method for predicting the circumferential waviness of a cylindrically ground part according to the present invention.

[0040] Figure 2 This is a schematic diagram of the external cylindrical grinding process of parts according to the present invention.

[0041] Figure 3 It is the predicted circumferential waviness profile of the part to be ground on the outer cylindrical surface, based on the first set of parameters in Example 2.

[0042] Figure 4 It is the predicted circumferential waviness profile of the part to be ground on the outer cylindrical surface, based on the second set of parameters in Example 2.

[0043] Figure 5 It is the predicted circumferential waviness profile of the part to be ground on the outer cylindrical surface when using the third set of parameters in Example 2. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0045] It should also be noted that, for ease of description, only the parts relevant to the present invention are shown in the accompanying drawings.

[0046] Where there is no conflict, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0047] Example 1

[0048] like Figure 1 As shown, a method for predicting the circumferential waviness of parts processed by external cylindrical grinding includes:

[0049] Step 1: Obtain the grinding wheel parameters and workpiece parameters for external cylindrical grinding. Grinding wheel parameters include: grinding wheel radius r. g (mm), Grinding wheel width B g (mm), grinding wheel runout error e r Workpiece parameters include: workpiece radius r w (mm); The circular runout error of the grinding wheel is obtained by measuring it during actual grinding rotation using a non-contact method.

[0050] Step 2: Obtain the machining motion parameters during external cylindrical grinding; the machining motion parameters include: workpiece rotational speed N. w (rpm), grinding wheel speed N g (rpm), feed rate V f (mm / min), grinding depth a p (mm).

[0051] Step 3: Calculate coefficients C1, C2, and C3.

[0052] Step 4: Calculate the circumferential waviness amplitude value of the external cylindrical grinding part using the parameters obtained in Steps 1 and 2 and the coefficients calculated in Step 3; Circumferential waviness amplitude value W of the external cylindrical grinding part. z The calculation formula is: C1 and C2 are amplitude calculation coefficients.

[0053] Step 5: Using the parameters obtained in Step 1, the coefficients calculated in Step 3, and the amplitude value calculated in Step 4, obtain the function of the circumferential waviness profile in the polar coordinate system. The function expression R(β) is: R(β) = r w +W z ·(1-sin(π(C3β-floor(C3β)))), where 0≤β≤2π, C3 is the contour calculation coefficient, β is the angle in the polar coordinate system, and floor() is the integer function that takes the largest integer less than or equal to the value.

[0054] Then, the circumferential ripple profile is obtained by inputting the function expression R(β) into mathematical plotting software.

[0055] In step three, C1, C2, and C3 are calculated as follows:

[0056] The formula for calculating the amplitude calculation factor C1 is as follows:

[0057] Critical speed N of the workpiece wc The calculation formula is:

[0058] The formula for calculating the amplitude calculation factor C2 is as follows:

[0059] The wave shift value T of the grinding wheel-workpiece speed ratio θ The calculation formula is: The formula for calculating the grinding width ratio n is: round() is a rounding function that takes the nearest integer value. f This refers to the grinding width.

[0060] The formula for calculating the profile calculation factor C3 is as follows:

[0061] Example 2

[0062] This embodiment takes the grinding of the outer diameter of a 45# steel shaft part as an example. The grinding process diagram is shown below. Figure 2 As shown, a white corundum grinding wheel was selected. The grinding waviness profile and amplitude value were predicted according to the method in Example 1.

[0063] Step 1: Obtain the grinding wheel parameters and workpiece parameters for external cylindrical grinding.

[0064] Step 2: Obtain the machining motion parameters during external cylindrical grinding. To compare different prediction results, three sets of parameters are listed, with variations in the grinding wheel speed.

[0065] Step 3: Calculate the coefficients C1, C2, C3, and N according to the formula. wc T θ And n. The calculation results of coefficients C1, C2 and C3.

[0066] Step 4: Calculate the circumferential wrench amplitude value w of the external cylindrical grinding part using the parameters obtained in Steps 1 and 2 and the coefficients calculated in Step 3. z Wz.

[0067] Step 5: Using the parameters obtained in Step 1, the coefficients calculated in Step 3, and the calculation results in Step 4, obtain the functional expression R(β) of the circular waviness profile in the polar coordinate system. Then, input this formula into mathematical plotting software to obtain the circular waviness profile, as shown in the appendix. Figure 3 Appendix Figure 4 and attached Figure 5 .

[0068] Theoretical predictions show that the waviness amplitude is maximized when the ratio of the grinding wheel speed to the workpiece speed is an integer; conversely, the waviness amplitude is significantly reduced when the speed ratio is non-integer, which aligns with practical production experience. This invention provides a theoretical basis for predicting whether the machining accuracy of parts is up to standard and for selecting appropriate machining parameters.

[0069] Example 3

[0070] A device for predicting the circumferential waviness of parts processed by external cylindrical grinding includes:

[0071] The parameter acquisition module is used to acquire the grinding wheel parameters and workpiece parameters during external cylindrical grinding; it is also used to acquire the machining motion parameters during external cylindrical grinding.

[0072] The amplitude calculation module is used to calculate the circumferential waviness amplitude of external cylindrical grinding parts based on grinding wheel parameters, workpiece parameters, and machining motion parameters.

[0073] The profile function module is used to obtain the function of the circumferential waviness profile in polar coordinates.

[0074] The contour drawing module is used to draw circular ripple contours based on functions.

[0075] Example 4

[0076] A terminal for predicting the circumferential waviness of a cylindrically ground part includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the above-described method for predicting the circumferential waviness of a cylindrically ground part.

[0077] Memory is used to store software programs and modules. The processor executes various terminal functions and data processing by running the software programs and modules stored in memory. Memory can mainly consist of a program storage area and a data storage area. The program storage area can store the operating system, at least one executable program required for a given function, etc.

[0078] The storage data area can store data created based on the use of the terminal. Furthermore, the memory can include high-speed random access memory, and may also include non-volatile memory, such as at least one disk storage device, flash memory, or other volatile solid-state storage devices.

[0079] A computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the above-described method for predicting the circumferential waviness of a cylindrically ground part.

[0080] Without loss of generality, computer-readable media can include computer storage media and communication media. Computer storage media includes volatile and non-volatile, removable and non-removable media implemented using any method or technology for storing information such as computer-readable instruction data structures, program modules, or other data. Computer storage media includes RAM, ROM, EPROM, EEPROM, flash memory or other solid-state storage technologies, CD-ROM, DVD or other optical storage, magnetic tape cassettes, magnetic tape, disk storage, or other magnetic storage devices. Of course, those skilled in the art will recognize that computer storage media are not limited to the above-mentioned types. The aforementioned system memories and mass storage devices can be collectively referred to as memory.

[0081] In the description of this specification, the references to terms such as "one embodiment / mode," "some embodiments / modes," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment / mode or example is included in at least one embodiment / mode or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment / mode or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments / modes or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments / modes or examples described in this specification, as well as the features of different embodiments / modes or examples.

[0082] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0083] Those skilled in the art should understand that the above embodiments are merely for illustrating the present invention and are not intended to limit the scope of the invention. Those skilled in the art can make other changes or modifications based on the above invention, and these changes or modifications still fall within the scope of the present invention.

Claims

1. A method for predicting the circumferential waviness of parts processed by external cylindrical grinding, characterized in that, include: Obtain the grinding wheel parameters and workpiece parameters during external cylindrical grinding. The grinding wheel parameters include: grinding wheel radius. Grinding wheel width Grinding wheel runout error The workpiece parameters include: workpiece radius. ; Obtain the machining motion parameters during external cylindrical grinding; the machining motion parameters include: workpiece rotation speed. Grinding wheel speed Feed rate Grinding depth ; Calculate the circumferential waviness amplitude value of the external cylindrical grinding part based on the grinding wheel parameters, workpiece parameters, and machining motion parameters; Obtain the function of the circumferential waviness profile in polar coordinates; Obtain the circumferential ripple profile based on function drawing; Among them, the circumferential waviness amplitude value of external cylindrical grinding parts The calculation formula is: ,in, , Calculate the coefficient for amplitude; Functional expression of circumferential waviness profile in polar coordinates for: ,in, , Calculate the coefficients for the profile. Angle in polar coordinates. A function to round up the largest integer less than or equal to the given value; Amplitude calculation coefficient The calculation formula is: ; Amplitude calculation coefficient The calculation formula is: ; Profile calculation coefficient The calculation formula is: ; in, The critical speed of the workpiece. This represents the wave shift value of the grinding wheel-workpiece speed ratio. Grinding width ratio; critical speed of workpiece The calculation formula is: ; Wave shift value of grinding wheel-workpiece speed ratio The calculation formula is: Grinding width ratio The calculation formula is: ; This is a function that rounds a value to the nearest integer. This refers to the grinding width.

2. The method for predicting the circumferential waviness of a cylindrically ground part according to claim 1, characterized in that, The circular runout error of the grinding wheel is obtained by measuring it during actual grinding rotation using a non-contact method.

3. The method for predicting the circumferential waviness of a cylindrically ground part according to claim 1, characterized in that, Circumferential ripple profile is expressed through a function expression. The data was obtained by inputting it into mathematical plotting software.

4. A terminal for predicting the circumferential waviness of a cylindrically ground part, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements a method for predicting the circumferential waviness of a cylindrical grinding part as described in any one of claims 1-3.

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