Grinding assistance device, display device, and storage medium

Abstract

The invention provides a grinding support device which can obtain tangential resistance according to various grinding conditions without using experimental values of specific grinding energy. Information for specifying a grinding condition when grinding the material to be cut by an amount of feed while rotating the grinding wheel and moving the material to be cut relative to the grinding wheel, and information for specifying a physical property value of the material to be cut are input to an input unit. The calculation unit calculates a tangential resistance applied to the working surface of the grinding wheel in the circumferential direction on the basis of information for specifying the grinding conditions and the physical property value of the material to be cut, which is input to the input unit, and finds a tangential resistance predicted value. The output unit outputs information indicating the tangential resistance predicted value obtained by the calculation unit.

Description

[0001] This application claims priority based on Japanese Patent Application No. 2023-128663 filed on August 7, 2023. The entire contents of the Japanese Patent Application are incorporated herein by reference. Technical Field

[0002] The invention relates to a grinding support device, a display device and a storage medium. Background Art

[0003] When determining the processing conditions for grinding, it is necessary to meet the required specifications such as roughness, waviness, geometric accuracy and processing time, and to find conditions that can be processed using a grinding machine. In the past, trial processing was performed under processing conditions determined by mobilizing accumulated processing data, the expertise of skilled workers, and the insights of manufacturers of grinding wheels and grinding machines or research institutions such as universities, and the optimal processing conditions were determined through repeated trials.

[0004] The grinding resistance generated during grinding is represented by the tangential resistance acting on the working surface (peripheral surface) of the grinding wheel in the tangential direction and the normal resistance acting on the working surface of the grinding wheel in the normal direction. In particular, the tangential resistance is directly related to the spindle power of the grinding machine (the power that rotates the grinding wheel), and the size of the tangential resistance is used to determine whether the existing grinding machine can be used for processing. In addition, the tangential resistance affects the processing energy efficiency.

[0005] In addition, part of the grinding resistance is converted into thermal energy and becomes grinding heat. Grinding heat causes defects such as grinding cracks and grinding warping. However, the grinding resistance varies greatly depending on the grinding conditions such as the material of the workpiece, the feed rate of the grinding wheel, the rotation speed of the grinding wheel, and the moving speed of the workpiece relative to the grinding wheel, so it is difficult to predict.

[0006] Next, a conventional grinding resistance prediction formula will be described.

[0007] The amount of work done by the grinding wheel on the material being cut depends on the volume of material being cut. The volume removed is proportional to the energy applied by the grinding wheel to the material being cut. If this is considered per unit time, the grinding wheel output power L [kW] is proportional to the removal volume speed q (mm 3 / s). The output power L of the grinding wheel is proportional to the peripheral speed V of the grinding wheel. s and tangential resistance F t The volume removal rate q is the product of the grinding width b and the feed amount Z. c and the moving speed V of the material being cut w If the proportionality constant between the grinding wheel output power L and the removal volume rate q is marked as k, the following equation holds.

[0008] [Formula 1]

[0009] L=F t ·V s = k·b·Z c ·V w …(1)

[0010] By transforming equation (1), the following equation can be obtained.

[0011] [Formula 2]

[0012]

[0013] From formula (2), we can see that the tangential resistance F t The moving speed V of the material being cut w is proportional to the grinding wheel peripheral speed V s It is inversely proportional.

[0014] The proportionality constant k is the grinding energy per unit volume [J / mm 3 ], which is called specific grinding energy. Patent Document 2 shows a method of using a conical abrasive grain model and calculating the tangential resistance F according to the specific grinding energy. t method.

[0015] Non-patent literature 1: Koichi Ichihara, Research on the grinding mechanism of multi-strip dressing grinding wheels Part 2: Evaluation method of grinding efficiency and the influence of the material of the workpiece, ABTEC2020

[0016] Non-patent document 2: Katsuo Shoji, Grinding Processing Engineering, Yangxiantang (2004), Chapter 5, page 88

[0017] In the method disclosed in Patent Document 2, the tangential resistance F can be calculated from the specific grinding energy. t , but it is not possible to predict the tangential resistance when grinding a cut material for which there is no data related to the specific grinding energy.

[0018] In the method shown in formula (1), formula (2) and non-patent document 2, the grinding energy consumed is only proportional to the volume removed, and the difference in efficiency caused by different grinding methods cannot be explained. For example, it can be seen that the volume removed when grinding once with a feed of 10 μm and grinding 10 times with a feed of 1 μm is the same, but in actual grinding, the grinding energy consumed when grinding 10 times with a feed of 1 μm is greater. It can be understood that this is because: as the size of the chips becomes smaller, the surface area cut per unit volume increases inversely proportional to the chip size, and the shear energy of the chips increases.

[0019] However, the previous tangential resistance prediction method does not reflect the influence of chip size, and cannot show the phenomenon that the grinding resistance per unit feed amount increases as the feed amount decreases. In addition, the experimental value of the specific grinding energy will differ based on the grinding conditions such as the dressing conditions or feed amount during the measurement. Therefore, if the grinding conditions when predicting the grinding resistance are different from the grinding conditions when the experimental value of the specific grinding energy is obtained, the prediction accuracy of the grinding resistance will decrease. Summary of the invention

[0020] An object of the present invention is to provide a grinding support device and a storage medium capable of obtaining tangential resistance according to various grinding conditions without using experimental values ​​of specific grinding energy.

[0021] According to one aspect of the present invention, there is provided a grinding support device comprising:

[0022] An input unit for inputting information for specifying grinding conditions and information for specifying physical property values ​​of a workpiece, wherein the grinding conditions are grinding conditions for grinding by causing the grinding wheel to rotate while causing the grinding wheel to cut into the workpiece by an amount of cutting and causing the workpiece to move relative to the grinding wheel;

[0023] a calculation unit that calculates a tangential resistance in a circumferential direction applied to a working surface of the grinding wheel and obtains a predicted value of the tangential resistance based on information input to the input unit for specifying the grinding conditions and the physical property values ​​of the cut material; and

[0024] The output unit outputs information indicating the predicted value of the tangential resistance obtained by the calculation unit.

[0025] According to another aspect of the present invention, a display device is provided, which displays as follows:

[0026] prompting input of information for specifying grinding conditions and information for specifying physical property values ​​of a workpiece, wherein the grinding conditions are grinding conditions in which the grinding wheel is rotated so that the grinding wheel cuts into the workpiece by an amount of cutting and the workpiece moves relative to the grinding wheel to perform grinding; and

[0027] Information indicating a predicted tangential resistance value obtained by calculating the tangential resistance in the circumferential direction applied to the working surface of the grinding wheel based on the input information for specifying the grinding conditions and the physical property values ​​of the cut material.

[0028] According to another aspect of the present invention, a storage medium is provided, wherein the program is executed by a computer to perform the following functions:

[0029] Acquiring information for specifying grinding conditions and physical property values ​​of a workpiece, wherein the grinding conditions are grinding conditions in which the grinding wheel is rotated so that the grinding wheel cuts into the workpiece by an amount of cutting and the workpiece moves relative to the grinding wheel to grind;

[0030] obtaining a predicted value of a tangential resistance in a circumferential direction applied to a working surface of the grinding wheel based on information for specifying the grinding conditions and the physical property values ​​of the cut material; and

[0031] The predicted value of the tangential resistance is output.

[0032] Effects of the Invention

[0033] The tangential resistance can be calculated for various workpiece materials or grinding conditions without using experimental values ​​of specific grinding energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a block diagram of the grinding support device according to the first embodiment and a schematic perspective view of the structure of a grinding machine that performs grinding and is supported by the grinding support device.

[0035] Figure 2 This is a flowchart for explaining the procedure of calculations performed by the calculation unit.

[0036] Figure 3 (A) is a schematic diagram of the material being cut and the grinding wheel being cut as viewed from the y direction. Figure 3 The middle part is a cross-sectional view of the grinding wheel and the material being cut parallel to the yz plane.

[0037] Figure 4 It indicates the physical properties of the material being cut, the grinding conditions, and the calculated shear area S( Figure 2 ), equivalent shear stress prediction value τ eq ( Figure 2 ), friction coefficient setting value μ, tangential resistance prediction value F t_pre , predicted value of normal resistance F n_pre , tangential resistance experimental value F t_exp And the normal resistance experimental value F n_exp of charts.

[0038] Figure 5 The predicted tangential resistance values ​​F calculated for the five types of cutting materials are t_pre and the experimental value of tangential resistance F t_exp Compare the displayed graphs.

[0039] Figure 6 It indicates the grinding conditions and the calculated shear area S( Figure 2 ), equivalent shear stress prediction value τ eq( Figure 2 ), predicted value of tangential resistance F t_pre , predicted value of normal resistance F n_pre , tangential resistance experimental value F t_exp , normal resistance experimental value F n_exp of charts.

[0040] Figure 7 Is to set the feed amount Z for each c The predicted tangential resistance value F t_pre and the experimental value of tangential resistance F t_exp Compare the displayed graphs.

[0041] Figure 8 This is a schematic diagram for explaining the grinding support device according to the second embodiment, in which a workpiece cut by a grinding wheel and a grinding wheel 54 are viewed from the y direction.

[0042] Fig. 9 The contact arc P is schematically represented based on a mathematical model. B0 P B1 ( Figure 8 The normal resistance F at any point on n and tangential resistance F t A graph of the size of .

[0043] In the figure: 10-grinding machine, 30-grinding support device, 31-input unit, 32-calculation unit, 33-output unit, 34-storage unit, 50-base, 51-worktable guiding mechanism, 52-movable worktable, 53-grinding wheel head, 54-grinding wheel, 55-lateral guide rail, 60-cutting material. DETAILED DESCRIPTION

[0044] Figure 1 This is a block diagram of the grinding support device 30 according to the first embodiment and a schematic structural perspective view of the grinding machine 10 that performs grinding and is the object of support of the grinding support device 30. The movable table 52 is supported on the base 50 via the table guide mechanism 51 so as to be reciprocatingly movable in one direction in the horizontal plane. An xyz rectangular coordinate system is defined in which the moving direction of the movable table 52 is the x direction and the downward direction of the plumb bob is the positive direction of the z axis. The workpiece 60 is supported on the movable table 52.

[0045] The grinding wheel head 53 is supported above the movable table 52. The grinding wheel head 53 can be raised and lowered and can move in a direction (y direction) in a plane perpendicular to the moving direction of the movable table 52. For example, the saddle is supported to be movable in the y direction along the traverse direction guide rail 55, and the grinding wheel head 53 is supported on the saddle so as to be raised and lowered.

[0046] A grinding wheel 54 is mounted at the lower end of the grinding wheel head 53. The grinding wheel 54 has a working surface along the side surface of the cylinder, and its central axis is parallel to the y-axis direction. When the grinding wheel head 53 is lowered and the lower end of the grinding wheel 54 is lowered to a level slightly below the surface of the workpiece 60, the workpiece 60 is moved in the grinding direction (x direction) while the grinding wheel 54 is rotated, thereby grinding the workpiece 60. The length in the z direction from the surface of the workpiece 60 to the lower end of the grinding wheel 54 during grinding is referred to as the feed amount.

[0047] The area where the grinding wheel 54 is ground when it is cut into the workpiece 60 and moved from one end of the workpiece 60 to the other end in the x direction is called a "path." By repeating the process of shifting the grinding wheel head 53 in the lateral direction (y direction) and the process of grinding one path, the entire area of ​​the upper surface (processed surface) of the workpiece 60 can be ground.

[0048] The grinding support device 30 includes an input unit 31 , a calculation unit 32 , an output unit 33 , and a storage unit 34 .

[0049] Information for specifying grinding conditions during grinding and information for specifying physical property values ​​of the material to be cut are input to the input unit 31. The input unit 31 may be a keyboard, a touch panel, a combination of a display and a pointing device, a removable medium reader / writer, a communication device, or the like.

[0050] The calculation unit 32 obtains a predicted value of the tangential resistance in the circumferential direction applied to the working surface of the grinding wheel 54 (hereinafter referred to as the predicted tangential resistance value) based on the information for specifying the grinding conditions and the information for specifying the physical property values ​​of the cut material input to the input unit 31. For example, the calculation unit 32 includes a microprocessing unit (MPU) that realizes the function of obtaining the predicted tangential resistance value by executing a program stored in the storage unit 34.

[0051] Information indicating the predicted value of the tangential resistance obtained by the calculation unit 32 is output from the output unit 33. As the output unit 33, for example, a display device (display), a reader / writer for a removable medium, a communication device, or the like can be used.

[0052] When the output unit 33 is a display device, a prompt may be displayed to prompt the user to input information for specifying grinding conditions and information for specifying physical property values ​​of the cut material. When the user sees the prompt and inputs the information for specifying grinding conditions and information for specifying physical property values ​​of the cut material into the input unit 31, the calculation unit 32 may obtain the predicted tangential resistance value and display information indicating the obtained predicted tangential resistance value on the display device.

[0053] In addition, as information indicating the predicted tangential resistance value, the display device may display information indicating whether the existing grinder can be used for processing based on the predicted tangential resistance value. Furthermore, as information indicating the predicted tangential resistance value, information notifying a user who is about to consider the specifications of the grinder based on the predicted tangential resistance value how much grinding output is required may also be displayed. In this way, the display device may calculate the predicted tangential resistance value based on the information for specifying the grinding conditions and the physical property values ​​of the cut material, and may display the specifications (conditions) of the grinder required by the user based on the predicted tangential resistance value.

[0054] Figure 2 32 is a flowchart for explaining the procedure of calculation performed by the calculation unit 32. Figure 1 ) physical properties such as tensile strength σ max , shear strength τ max , elongation E L The value of is input to the input unit 31 ( Figure 1 ). In addition, according to von Mises' shear energy theory, under the tensile strength σ max and shear strength τ max The following relationship exists between them.

[0055] [Formula 3]

[0056]

[0057] Therefore, if the tensile strength σ is input to the input unit 31 max and shear strength τ max One of the values ​​in will do.

[0058] Grinding wheel diameter D and feed amount Z as grinding conditions c , grinding width b, grinding wheel speed N, moving speed V of the cut material w and grinding wheel peripheral speed V s The value of is input to the input unit 31 ( Figure 1 ). In addition, at the grinding wheel peripheral speed V s , there is the following relationship between the grinding wheel diameter D and the grinding wheel speed N.

[0059] [Formula 4]

[0060] V s =N·π·D…(4)

[0061] Therefore, as long as the grinding wheel peripheral speed V is input to the input unit 31 s , at least two values ​​of the grinding wheel diameter D and the grinding wheel speed N are sufficient.

[0062] The calculation unit 32 calculates the tensile strength σ max and shear strength τmax An input value and elongation E L The equivalent shear stress is calculated by using the input value of eq About the predicted value of equivalent shear stress τ eq The calculation method of will be described later. c , grinding width b, grinding wheel speed N and moving speed V of the cut material w The shearing area is calculated and the shearing area calculated value S is obtained. The calculation method of the shearing area calculated value S will be described later.

[0063] The calculation unit 32 obtains the predicted tangential resistance value F according to the following formula: t_pre .

[0064] [Formula 5]

[0065] F t_pre =τ eq ·S…(5)

[0066] Then, the friction coefficient μ between the grinding wheel and the workpiece is used to calculate the normal resistance prediction value F according to the following formula: n_pre .

[0067] [Formula 6]

[0068]

[0069] Next, refer to Figure 3 and Figure 4 , to find the predicted value of equivalent shear stress τ eq The method of calculating the shear area value S is described below.

[0070] Figure 3 (A) is a schematic diagram of the grinding wheel 54 and the cut material 60 cut by the grinding wheel 54 as viewed from the y direction. Figure 3 (B) is a cross-sectional view of the grinding wheel 54 and the workpiece 60 parallel to the yz plane. The length in the z direction from the surface of the workpiece 60 to the lowest point of the grinding wheel 54 corresponds to the cutting amount Z c In fact, the cut material 60 moves relative to the grinding wheel 54 along the positive direction of the x-axis, but Figure 3 In (A), the grinding wheel 54 moves from the position indicated by the solid line to the position indicated by the dotted line in the negative direction of the x-axis relative to the workpiece 60. That is, it can be regarded as the grinding wheel 54 moving in the negative direction of the x-axis at a moving speed V w The grinding wheel 54 rotates as follows: at the lowest point of the grinding wheel 54, the working surface of the grinding wheel 54 moves in the same direction as the moving direction of the grinding wheel 54 (the negative direction of the x-axis) at a peripheral speed Vs move.

[0071] Grinding width b( Figure 3 (B) is the dimension in the y direction of the portion of the workpiece 60 that is ground by the grinding wheel 54 .

[0072] The lowest point of the grinding wheel 54 shown by the solid line is marked as P A0 The intersection of the grinding wheel 54 and the surface of the workpiece 60 shown by the solid line is marked as P A1 The lowest point of the grinding wheel 54 shown by the dotted line is marked as P B0 The intersection of the grinding wheel 54 and the surface of the workpiece 60 shown by the dotted line is marked as P B1 . From point P A0 To point P A1 The grinding wheel 54 is in contact with the workpiece 60 in the arc portion. This arc is called the contact arc. A0 Arrival point P A1 During the period of the contact arc, the grinding wheel 54 moves to the position shown by the dotted line. This moving distance is referred to as the movement amount λ per contact arc. c From point P A0 To point P A1 The length of the contact arc from point P B0 To point P B1 The length of the contact arc is equal to that of the contact arc. The length of the contact arc is called the contact arc length L c .

[0073] Movement per contact arc λ c And the contact arc length L c It can be calculated by the following formula.

[0074] [Formula 7]

[0075]

[0076] If the grinding wheel 54 moves only by the amount λ per contact arc c , then the contact arc P A0 P A1 , straight line P A1 P B1 , contact arc P B1 P B0 and straight line P B0 P A0 The cut material 60 in the enclosed area is ground to become chips. The portion that becomes chips is referred to as a chip portion. The length L of the cross section of the chip portion is s The following formula can be used to approximate it. Usually, the feed amount Z c is in μm level, and the tangent arc length is L cIt is in the mm level, so the following approximation holds true.

[0077] [Formula 8]

[0078] L s ≈L c +λ c …(8)

[0079] Tangential resistance F t This corresponds to the shear force on the shearing surface of the cut material to form chips. A0 P A1 The shear force is applied in the form of friction force in the tangential direction of the grinding wheel 54 dragging the cut material 60 in the circumferential direction. The shear force is applied only during the period when the metal bond between the chip side and the cut side is displaced and deformed and thus stretched. If the metal bond is broken, the shear force becomes zero.

[0080] The chip portion on the shear plane is displaced relative to the workpiece 60 by the chip portion moving together with the working surface of the grinding wheel 54. Assuming that the chip portion is displaced by a distance L s When the metal bond breaks, the elongation of the cut material 60 on the shear surface becomes 100%. However, the elongation of ordinary metal materials is less than 100%. That is, regarding the shear force, the length L of the cross section of the chip portion dragged by the grinding wheel 54 is s The metal bonds are cut in the process and the shear force becomes zero. Therefore, the shear force does not extend over the length L of the chip cross section. s produced over the entire length of the

[0081] It can be considered that the deformation strain of the shear surface is proportional to the elongation of the physical property value of the cut material 60, so it can be considered that the shear failure stress is reduced to the shear strength τ which is the physical property value of the cut material 60. max Multiply by the elongation E L Based on this study, the equivalent shear stress prediction value τ is defined by the following formula: e q .

[0082] [Formula 9]

[0083]

[0084] Add to elongation E L The exponent n is used to compensate the final predicted tangential resistance value F t_pre and tangential resistance F t For example, as the exponent n, 1.2 can be used. η th is used to make the shear strength τ max and the predicted value of equivalent shear stress τ eqThe magnitude of the correction factor matches the shear strength τ max and elongation E L The value obtained by multiplication is about two orders of magnitude larger than the shear stress value obtained in the actual machine test, so a correction factor η is introduced. th For example, as η th , use 0.040.

[0085] Below, the equivalent shear stress prediction value τ eq The reason why the shear stress value obtained in the actual machine test differs by about two orders of magnitude is explained below.

[0086] The chips are subjected to friction and shear force from the grinding wheel and instantly become a high temperature state close to 1000°C, so sparks can be observed during grinding. The parts around the chips of the cut material also become hot and soften, which leads to a significant decrease in shear strength. For example, it is known that the tensile strength of stainless steel σ max When the temperature rises from room temperature to 1000°C, it decreases by about one order of magnitude. In the actual machine test, the shear stress reflecting the decrease in shear strength was measured, and the equivalent shear stress prediction value τ eq The reduction in shear strength due to softening is not reflected in the calculation of . Therefore, there is a difference of about two orders of magnitude between the two.

[0087] Shear area calculation value S( Figure 2 ) can be calculated based on the length L of the cross section of the chip part. s And the grinding width b is calculated by the following formula.

[0088] [Formula 10]

[0089] S=b·L s …(10)

[0090] If the grinding wheel diameter D and feed amount Z are provided as grinding conditions c , grinding width b, grinding wheel speed N and moving speed V of the cut material w , the shear area calculation value S can be calculated according to equations (7), (8) and (10).

[0091] If the equivalent shear stress prediction value τ is obtained eq and the calculated shear area value S, the predicted tangential resistance value F can be calculated according to equations (5) and (6): t_pre and the predicted value of normal resistance F n_pre .

[0092] A study was conducted to confirm the predicted tangential resistance value F obtained using the grinding support device 30 according to the first embodiment. t_pre and the predicted value of normal resistance Fn_pre Next, refer to the accuracy evaluation experiment. Figure 4 and Figure 5 The results of the evaluation experiment will be described below. In the evaluation experiment, SUS304, SS400, S55C, NAK55, and FC250 were used as the workpiece 60 .

[0093] Figure 4 is the physical property value of the cut material 60, the grinding conditions, and the shear area calculation value S( Figure 2 ), equivalent shear stress prediction value τ eq ( Figure 2 ), friction coefficient setting value μ, tangential resistance prediction value F t_pre , predicted value of normal resistance F n_pre , tangential resistance experimental value F t_exp And the normal resistance experimental value F n_exp As the physical property value of the cut material 60, the tensile strength σ is shown. max , shear strength τ max And elongation E L The grinding conditions are shown as follows: grinding wheel diameter D, grinding wheel speed N, and moving speed V of the workpiece. w , Feed amount Z c And grinding width b.

[0094] As the friction coefficient setting value μ, for example, a value measured by the method described below can be used.

[0095] Prepare a sample of the grinding wheel 54 and a sample of the cut material 60. Prepare a grinding wheel having a flat working surface (e.g., a rectangular parallelepiped shape) as the sample of the grinding wheel 54. Make the working surface of the sample of the grinding wheel 54 contact the cut surface of the cut material 60, and fix one of the sample of the grinding wheel 54 and the sample of the cut material 60 to the inclined surface.

[0096] If the inclination angle of the inclined surface is gradually increased, the sample of the grinding wheel 54 and the sample of the workpiece 60 that is not fixed to the inclined surface will start to slide. The tangent of the angle at this time is equivalent to the static friction coefficient. This static friction coefficient can be used as the friction coefficient setting value μ.

[0097] In the calculation, the exponent n of formula (9) is set to 1.2, and the correction coefficient η is th Set to 0.040. In addition, the index n and the correction coefficient η th The most appropriate value of can be found by conducting evaluation experiments on various cutting materials 60.

[0098] Tangential resistance experimental value F t_exp And the normal resistance experimental value F n_expThe force can be obtained by grinding the workpiece 60 under the grinding conditions actually provided and measuring the force applied to the workpiece 60 .

[0099] Figure 5 The predicted tangential resistance values ​​F obtained for the five types of cut materials 60 are t_pre and the experimental value of tangential resistance F t_exp The curve diagram shown in the figure shows that no matter which material 60 is being cut, the predicted tangential resistance value F t_pre and the experimental value of tangential resistance F t_exp Also extremely similar.

[0100] Moreover, when the feed amount Z is changed c In the case of t_pre and the predicted value of normal resistance F n_pre The accuracy of the test is evaluated by the experiment. Figure 6 and Figure 7 The results of the evaluation experiment are described below. In the evaluation experiment, FC250 was used as the workpiece 60, and the feed amount Z was changed within the range of 1 μm to 20 μm. c .

[0101] Figure 6 It indicates the grinding conditions and the calculated shear area S( Figure 2 ), equivalent shear stress prediction value τ eq ( Figure 2 ), predicted value of tangential resistance F t_pre , predicted value of normal resistance F n_pre , tangential resistance experimental value F t_exp And the normal resistance experimental value F n_exp For the feed amount Z c Five cases of 1 μm, 2 μm, 5 μm, 10 μm and 20 μm were evaluated.

[0102] Figure 7 Is to set the feed amount Z for each c The predicted tangential resistance value F t_pre and the experimental value of tangential resistance F t_exp Compare the curves shown. It can be seen from the figure that no matter the feed amount Z c What is the predicted value of tangential resistance F? t_pre and the experimental value of tangential resistance F t_exp Also extremely similar.

[0103] Next, the excellent effects of the first embodiment will be described.

[0104] In the first embodiment, the predicted tangential resistance value F can be obtained based on the physical properties of the material being cut and the grinding conditions. t_pre and the predicted value of normal resistance F n_pre Therefore, even for a workpiece without data on specific grinding energy, the predicted tangential resistance value F can be calculated. t_pre and the predicted value of normal resistance F n_pre .

[0105] Then, the tangential resistance F calculated using the conventional method shown in formula (2) is t and feed amount Z c However, based on experience, as an example, even if the feed amount Z c From 10μm to 1μm, the tangential resistance F t In the first embodiment, if Figure 7 As shown, when the feed amount Z c When the diameter of the tangential resistance is reduced from 10 μm to 1 μm, the predicted value F e_pre It is not 1 / 10, but about 1 / 3. This is consistent with the experimental value of tangential resistance F t_exp Thus, in the first embodiment, for various feed amounts Z c , can more accurately predict the tangential resistance F t .

[0106] If the predicted tangential resistance F is obtained t_pre and the predicted value of normal resistance F n_pre , it is possible to predict the Figure 1 ) The power required for rotation. For example, when introducing a new grinding machine, the predicted value of tangential resistance F t_pre and the predicted value of normal resistance F n_pre This is useful information for determining the specifications of the grinding machine to be introduced. In addition, when using an existing grinding machine for grinding, the predicted tangential resistance value F t_pre and the predicted value of normal resistance F n_pre This is useful information for determining grinding conditions.

[0107] Next, the grinding support device according to the second embodiment will be described. Figure 1 to Figure 7 The grinding support device described in the first embodiment is similar in structure to the grinding support device described in the first embodiment. In the first embodiment, it is assumed that the length L of the cross section of the chip portion represented by the formula (8) is s Shearing is performed over the entire length of the cutting material 60, but in the second embodiment, the friction zone in which the working surface of the grinding wheel 54 slides relative to the cutting material 60 is considered and the tangential resistance and the normal resistance are predicted.

[0108] The chips are generated as follows: abrasive grains or dressing layer blades are embedded in the cut surface and cut off from the cut surface by shear force. As a result, grooves are formed on the cut surface to show the traces of the chips being removed. It can be considered that the tangential resistance of the grinding wheel 54 is the resistance to shear failure of the shear surface acting on the chips.

[0109] Shear force F s is the product of shear stress and shear area, so the shear strength τ of the cut material 60 is used. max The shear area calculation value S during grinding is obtained as follows. In the following formula, the shear area calculation value S is transformed using formula (10).

[0110] [Formula 11]

[0111] F s =τ max S = τ max ·b·L s …(11)

[0112] Figure 8 is a schematic diagram of a material 60 and a grinding wheel 54 cut by a grinding wheel 54 as viewed from the y direction, which shows the same Figure 3 The same state as shown in (A).

[0113] From the center point of the grinding wheel 54 shown by the solid line toward point P A1 The intersection of the extended line of the radius and the outer circumference of the grinding wheel 54 shown by the dotted line is marked as P m . A1 P m The length is set as the maximum cutting depth h max The amount of interference between the cut material 60 and the grinding wheel 54 is at point P. m The surface pressure is also at point P. m becomes the maximum. That is, the tangential resistance F t Also click P m Become the biggest.

[0114] If the friction coefficient between the grinding wheel 54 and the workpiece 60 is represented by μ, and the contact surface pressure is represented by σ n , the small length in the tangential direction of the part where the contact surface pressure is applied is marked as dl, then the tangential resistance F t The record is as follows.

[0115] [Formula 12]

[0116] F t =∫μσ n bdl…(12)

[0117] If point Pm The contact surface pressure at n_max , then take point P B0 When it is the origin, the contact arc P B0 P B1 The contact surface pressure σ at any point on n It increases roughly in proportion to the distance l from the origin. c (Equation (8)) is used to approximate the origin P B0 To point P m The distance l to the contact surface is n It is expressed as the following formula.

[0118] [Formula 13]

[0119]

[0120] If the contact surface pressure σ in equation (13) is n Substituting into equation (12), we can obtain the following equation.

[0121] [Formula 14]

[0122]

[0123] If the tangential resistance F t Shear force F exceeding 60% of the material being cut s , the chip part moves along the contact arc due to shear failure, and the tangential resistance F t becomes the shear force F s Equal. In the tangential resistance F t Less than the shear force F of the cut material 60 s When the working surface of the grinding wheel 54 is in the contact arc P A0 P A1 Slide upward, thus generating friction resistance.

[0124] Maximum contact surface pressure σ n_max The contact rigidity K between the grinding wheel 54 and the cut material 60 can be used. E , click P m Maximum feed h max It is expressed as the following formula

[0125] [Formula 15]

[0126] σ n_max =K E h max …(15) If the continuous cutting edge interval is set to the contact arc length L c If they are equal, the maximum feed amount h max It can be expressed by the following formula.

[0127] [Formula 16]

[0128]

[0129] If equations (15) and (16) are substituted into equation (14), the maximum tangential resistance F can be obtained by the following equation: t_max .

[0130] [Formula 17]

[0131]

[0132] If equation (17) is integrated to the contact arc length L c And the shear force F in formula (11) s The maximum tangential resistance F in formula (17) t_max Set them equal and find the shear length L s , the following formula can be obtained.

[0133] [Formula 18]

[0134]

[0135] Fig. 9 The contact arc P is schematically represented based on the above mathematical model. B0 P B1 The normal resistance F at any point on n and tangential resistance F t The horizontal axis is equivalent to the value from point P. B0 Along the contact arc P B0 P B1 Towards point P B1 The vertical axes of the upper and lower graphs represent the normal resistance F. n and tangential resistance F t The point with length L1 is equivalent to the shear starting point, and the point with length L2 is equivalent to the point P with the maximum contact surface pressure. m ( Figure 8 ). In the interval from the origin to the length L1, due to the normal resistance F n The working surface of the grinding wheel 54 slides on the contact arc. Therefore, the sliding friction resistance F r If the length from the origin exceeds L1, shearing begins and the tangential resistance F t Will rise to the shear force F s The length of the shear is marked as the shear length L s .

[0136] In the first embodiment, as shown in equation (8), it is assumed that shearing occurs in the entire area of ​​the contact arc. In the second embodiment, a section where sliding occurs and a section where shearing occurs are distinguished.

[0137] If the maximum sliding friction resistance is marked as F r_max , then the average value of the friction resistance (hereinafter referred to as the average value of the friction resistance F r_ave ) becomes the maximum sliding friction resistance F r_max And, the normal resistance is at point P which is L2 from the origin. m The maximum value of normal resistance is marked as F n_max The average value of normal resistance F n_ave The maximum value F n_max 1 / 2 of.

[0138] Shear force F s The chip is displaced on the shear plane and breaks when the deformation exceeds the limit of plastic deformation. If the chip is broken, the tangential resistance F t Become zero.

[0139] The displacement on the shearing surface is generated by the contact surface of the chip portion and the working surface of the grinding wheel 54 moving together. s If the elongation of the chip shear surface is equal to 100%, the elongation of the chip shear surface becomes 100%, but the elongation of the physical property value of ordinary metal materials is less than 100%. Therefore, the effective shear length to which the shear force is applied becomes the shear length L s The value obtained by multiplying the elongation of the cut material 60. This is equivalent to the shear force F s Reduce to elongation E L times.

[0140] Therefore, the average value of the tangential resistance during cutting contact arc (hereinafter referred to as the average value of the tangential resistance F t_ave ) can be calculated by the following formula by adding the sliding friction resistance and shear resistance weighted by the lengths they act on.

[0141] [Formula 19]

[0142]

[0143] As in formula (6), the average value of normal resistance F n_ave According to the average tangential resistance F t_ave If equation (19) is expressed in terms of stress, the following equation can be obtained.

[0144] [Formula 20]

[0145]

[0146] The average shear stress τ ave Corresponding to the equivalent shear stress predicted value τ obtained in the first embodiment eq(Formula (9)), the average value of tangential resistance F t_ave Corresponding to the predicted tangential resistance value F obtained in the first embodiment t_pre ( Figure 2 ). Therefore, the average value of shear stress τ ave It is called the equivalent shear stress prediction value, which can be expressed as the average value of the tangential resistance F t_ave It is called the predicted value of tangential resistance.

[0147] Next, the excellent effects of the second embodiment will be described.

[0148] In the second embodiment, the average tangential resistance F can be obtained using equation (19): t_ave . In Fig. 9 The origin P shown B0 The range of the start length L1 takes into account the sliding of the working surface of the grinding wheel 54 with respect to the workpiece 60. Therefore, the phenomenon of grinding can be described in more detail.

[0149] The above embodiments are examples. Of course, the structures shown in different embodiments can be partially replaced or combined. The same effects based on the same structure in multiple embodiments are not mentioned one by one in each embodiment. Moreover, the present invention is not limited to the above embodiments. For example, the present invention can be subjected to various changes, improvements, combinations, etc., which are obvious to those skilled in the art.

Claims

1. A grinding support device, characterized in that: have: An input unit for inputting information for specifying grinding conditions and information for specifying physical property values ​​of a workpiece, wherein the grinding conditions are grinding conditions for grinding by causing the grinding wheel to rotate while causing the grinding wheel to cut into the workpiece by an amount of cutting and causing the workpiece to move relative to the grinding wheel; a calculation unit that calculates a tangential resistance in a circumferential direction applied to a working surface of the grinding wheel and obtains a predicted value of the tangential resistance based on information input to the input unit for specifying the grinding conditions and the physical property values ​​of the cut material; and The output unit outputs information indicating the predicted value of the tangential resistance obtained by the calculation unit.

2. The grinding support device according to claim 1, characterized in that The calculation unit calculates the normal resistance applied to the working surface of the grinding wheel in the normal direction according to the predicted tangential resistance value, and obtains the predicted normal resistance value. The output unit outputs the normal resistance prediction value obtained by the calculation unit.

3. The grinding support device according to claim 1 or 2, characterized in that: The physical property values ​​of the cut material input to the input unit include the tensile strength or shear strength and elongation of the cut material. The computing unit is configured as follows: The equivalent shear stress is obtained based on the tensile strength or shear strength of the material to be cut and the elongation of the material to be cut input to the input unit. According to the grinding conditions, a shearing area of ​​the workpiece is obtained during a period in which the grinding wheel rotates and the lowest point of the grinding wheel moves to the surface of the workpiece. The predicted value of the tangential resistance is obtained by multiplying the equivalent shear stress by the shear area.

4. The grinding support device according to any one of claims 1 to 3, characterized in that: The grinding conditions input to the input unit include information indicating the cutting amount of the grinding wheel, the grinding width, the diameter of the grinding wheel, the rotation speed of the grinding wheel, and the moving speed of the workpiece relative to the grinding wheel.

5. The grinding support device according to claim 4, characterized in that: The calculation unit is configured to calculate the shear area by multiplying the grinding width by the sum of a circumferential length of the working surface of the grinding wheel from the lowest point of the grinding wheel to the surface of the cutting material, i.e., a contact arc length, and a length of movement of the cutting material relative to the grinding wheel during a period in which the grinding wheel rotates and the lowest point of the grinding wheel moves to the surface of the cutting material.

6. A display device, characterized in that: The display is as follows: a prompt for inputting information for specifying grinding conditions and information for specifying physical property values ​​of a workpiece, wherein the grinding conditions are grinding conditions in which the grinding wheel is rotated so as to cut into the workpiece by an amount and the workpiece is relatively moved relative to the grinding wheel; and Information indicating a predicted tangential resistance value obtained by calculating the tangential resistance in the circumferential direction applied to the working surface of the grinding wheel based on the input information for specifying the grinding conditions and the physical property values ​​of the cut material.

7. A storage medium storing a program, characterized in that: The program is executed by the computer to perform the following functions: Acquiring information for specifying grinding conditions and physical property values ​​of the cut material, wherein the grinding conditions are grinding conditions for grinding by rotating a grinding wheel, causing the grinding wheel to cut into the cut material by a certain amount, and causing the cut material to move relative to the grinding wheel; obtaining a predicted value of a tangential resistance in a circumferential direction applied to a working surface of the grinding wheel based on information for specifying the grinding conditions and the physical property values ​​of the cut material; and The predicted value of the tangential resistance is output.

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