Grinding method and device for eccentric peripheral relief surface, numerical control machine and storage medium

Abstract

The application relates to a grinding method and device of an eccentric peripheral flank face, a numerical control machine and a storage medium. The method comprises the following steps: acquiring a peripheral helical blade line function; acquiring a transformation matrix for converting a peripheral coordinate system to a workpiece coordinate system; the peripheral coordinate system is established with a blade line point of the peripheral helical blade line function as an origin; the workpiece coordinate system is established with a tool rotary shaft as one of the coordinate axes; performing coordinate system transformation based on the transformation matrix and an initial grinding wheel position in the peripheral coordinate system to obtain a target grinding wheel grinding track in the workpiece coordinate system; performing coordinate system transformation based on the transformation matrix and an initial grinding wheel axis vector in the peripheral coordinate system to obtain a target grinding wheel axis vector in the workpiece coordinate system; and performing eccentric peripheral flank face grinding based on the target grinding wheel grinding track and the target grinding wheel axis vector. The method can improve the tool blade strength and the machining surface quality.

Description

Technical Field

[0001] This application relates to the field of computer technology, and in particular to a grinding method, apparatus, CNC machine, and storage medium for an eccentric circumferential cutting edge. Background Technology

[0002] The peripheral flank of a solid end mill is primarily used to reduce friction between the tool and the workpiece transition surface, thereby improving the machined surface. It is one of the key structural features of an end mill. Depending on the grinding process, the three cross-sectional shapes of the ground end mill flank are: planar, eccentric, and concave. Currently, the planar flank is the most commonly used, but its grinding effect is unsatisfactory. Therefore, there is an urgent need to propose a flank grinding method to improve the surface quality of the machined material. Summary of the Invention

[0003] Therefore, it is necessary to provide a grinding method, apparatus, CNC machine, and storage medium for an eccentric peripheral cutting edge flank that can improve the cutting edge strength and surface quality of the tool, in order to address the above-mentioned technical problems.

[0004] A grinding method for an eccentric peripheral cutting edge flank, the method comprising:

[0005] Function to obtain the peripheral spiral cutting edge line;

[0006] Obtain the transformation matrix that transforms the peripheral cutting edge coordinate system to the workpiece coordinate system; the peripheral cutting edge coordinate system is established with the cutting edge point of the peripheral cutting edge spiral cutting edge function as the origin; the workpiece coordinate system is established with the tool rotation axis as one of the coordinate axes;

[0007] Based on the transformation matrix and the initial grinding wheel position in the peripheral coordinate system, a coordinate system transformation is performed to obtain the target grinding wheel grinding trajectory in the workpiece coordinate system.

[0008] Based on the transformation matrix and the initial grinding wheel axis vector in the peripheral coordinate system, a coordinate system transformation is performed to obtain the target grinding wheel axis vector in the workpiece coordinate system.

[0009] Eccentric peripheral cutting face grinding is performed based on the target grinding wheel grinding trajectory and the target grinding wheel axis vector.

[0010] A grinding device for an eccentric peripheral cutting edge face, the device comprising:

[0011] The function acquisition module is used to obtain the function for the circumferential spiral cutting edge line;

[0012] The transformation matrix acquisition module is used to acquire the transformation matrix for transforming the peripheral cutting edge coordinate system to the workpiece coordinate system; the peripheral cutting edge coordinate system is established with the cutting edge point of the peripheral cutting edge spiral cutting edge function as the origin; the workpiece coordinate system is established with the tool rotation axis as one of the coordinate axes;

[0013] The trajectory determination module is used to perform coordinate system transformation based on the transformation matrix and the initial grinding wheel position in the peripheral coordinate system to obtain the target grinding wheel grinding trajectory in the workpiece coordinate system.

[0014] The grinding wheel axis vector determination module is used to perform coordinate system transformation based on the transformation matrix and the initial grinding wheel axis vector in the peripheral coordinate system to obtain the target grinding wheel axis vector in the workpiece coordinate system.

[0015] The grinding module is used to perform eccentric peripheral cutting face grinding based on the grinding trajectory of the target grinding wheel and the axis vector of the target grinding wheel.

[0016] A CNC machine includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps of an embodiment of a grinding method for each eccentric peripheral cutting face.

[0017] A computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of an embodiment of a grinding method for each eccentric circumferential cutting edge.

[0018] The aforementioned grinding method, apparatus, CNC machine, and storage medium for eccentric peripheral cutting tool faces establish a peripheral coordinate system with the cutting edge point of the peripheral spiral cutter as the origin, and a workpiece coordinate system with the tool rotation axis as one of the coordinate axes. Since it is difficult for the CNC machine to perform tool grinding in the peripheral coordinate system, a transformation matrix is ​​obtained to transform the peripheral coordinate system to the workpiece coordinate system. The transformation matrix contains variables related to the cutting edge point. Therefore, the initial grinding wheel axis vector can be transformed into a coordinate system based on the transformation matrix to obtain the target grinding wheel grinding trajectory and the target grinding wheel axis vector. This enables the CNC machine to perform eccentric peripheral cutting tool face grinding in the workpiece coordinate system. The obtained eccentric peripheral cutting tool face has a large tool tip angle, high tool edge strength, and good cutting performance and surface quality. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of three cross-sectional shapes of the flank face of an end mill in one embodiment;

[0020] Figure 2 This is an application environment diagram of a grinding method for an eccentric peripheral cutting edge in one embodiment;

[0021] Figure 3 This is a schematic diagram of the workpiece coordinate system and tool parameters in one embodiment;

[0022] Figure 4 This is a schematic diagram of the peripheral coordinate system and tool parameters in one embodiment;

[0023] Figure 5 This is a schematic diagram of the rear arc of the circumferential cutting edge in one embodiment;

[0024] Figure 6 This is a schematic flowchart of a grinding method for an eccentric peripheral cutting edge face in one embodiment;

[0025] Figure 7 This is a schematic diagram of the initial grinding posture of the grinding wheel in one embodiment;

[0026] Figure 8 This is a schematic diagram of the calculation model for the grinding wheel tilt angle in one embodiment;

[0027] Figure 9 This is a schematic diagram of the grinding result of an eccentric flank face in one embodiment;

[0028] Figure 10 This is a structural block diagram of a grinding device for an eccentric peripheral cutting edge in one embodiment;

[0029] Figure 11 This is an internal structural diagram of a CNC machine in one embodiment. Detailed Implementation

[0030] It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0031] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0032] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly. The connection can be a direct connection or an indirect connection.

[0033] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0034] In one embodiment, Figure 1 This is a schematic diagram of three cross-sectional shapes of the flank face of an end mill in one embodiment. Figure 1The types are a. planar, b. eccentric, and c. concave. Currently, the planar type is the most commonly used. However, from the perspective of reducing friction and ensuring the cutting edge strength, the overall performance of both the planar and concave types of clearance angles is inferior to that of the eccentric type. Therefore, this application provides a grinding method for an eccentric peripheral clearance face. The eccentric peripheral clearance face obtained by this method has a larger tip angle, higher cutting edge strength, and better cutting performance and surface finish.

[0035] Furthermore, the grinding methods for flat and concave flank faces are relatively simple. Flat flank faces are ground using the large end face of the grinding wheel, while concave flank faces are ground using the side of the grinding wheel, which represents the curvature of the concave surface. However, the grinding of eccentric flank faces is more complex.

[0036] The grinding method for the eccentric peripheral cutting edge provided in this application can be applied to, for example... Figure 2 In the application environment. Figure 2 This is an application environment diagram of a grinding method for an eccentric peripheral cutting edge in one embodiment. Figure 2 The system includes a CNC machine 200, which contains a grinding wheel 210. The grinding wheel 210 is used to grind the tool 220 to be ground.

[0037] 1.1 Workpiece coordinate system O w -X w Y w Z w

[0038] For ease of understanding, let's establish... Figure 3 The workpiece coordinate system O shown w -X w Y w Z w . Figure 3 This is a schematic diagram of the workpiece coordinate system and tool parameters in one embodiment. The coordinate system is based on the tool rotation axis as Z. w The axis is defined by the bottom rotating end face of the end mill tooth as X. w O w Z w The plane, with the center of the rotating end face as the origin O. w .

[0039] 1.2 Zhouren Coordinate System O m -X m Y m Z m

[0040] Let any point on the helical cutting edge be the grinding point P, and define O m -X m Y m Z m Let be the coordinate system of the moving edge. Figure 4This is a schematic diagram of the peripheral cutting edge coordinate system and tool parameters in one embodiment. The Z-axis of the peripheral cutting edge coordinate system is... m With coordinate axis Z w Parallel, origin O m Coinciding with point P, coordinate axis Y m It is parallel to the tangent of the outer contour of the workpiece.

[0041] Tool parameter definition:

[0042] (1) Blade length L w

[0043] In the workpiece coordinate system, the length of the cutting edge along the tool axis is defined as the cutting edge length L. w .

[0044] (2) Tool starting rotation radius R w

[0045] In the workpiece coordinate system, the tool rotation radius at the starting point of the circumferential helical cutting edge is defined as the tool initial rotation radius R. w .

[0046] (3) Helix angle β

[0047] In the workpiece coordinate system, the angle between the helical tangent vector and the tool axis is the helical angle β.

[0048] (4) Back angle α of the circular arc of the circumferential blade

[0049] like Figure 5 The diagram shown illustrates the back angle of the peripheral cutting edge in one embodiment. In the peripheral cutting edge coordinate system, the tangent at the tip of the cutting edge's back face intersects with the Y-axis. m The included angle of the axis is the arc back angle α.

[0050] (5) Taper angle of the inverted cone of the circumferential blade k

[0051] In the workpiece coordinate system, the angle between the outer contour of the tool's rotating body and the axis of the tool's rotation center is defined as the taper angle k.

[0052] like Figure 6 The diagram shown is a schematic flowchart of a grinding method for an eccentric peripheral cutting edge flank in one embodiment. The method is illustrated using an application on a CNC machine as an example, and includes:

[0053] Step 602: Obtain the peripheral spiral cutting edge line function.

[0054] The peripheral spiral cutting edge line function can be pre-existing in the CNC machine or generated based on the peripheral spiral cutting edge parameter values ​​input by the user.

[0055] Specifically, the CNC machine acquires the input parameters of the circumferential spiral cutting edge and inputs these parameters into a preset circumferential spiral cutting edge model to obtain the circumferential spiral cutting edge function. The input parameters of the circumferential spiral cutting edge may include the initial rotation angle. Tool starting rotation radius R w And the helix angle β, and may also include the taper angle k.

[0056] Step 604: Obtain the transformation matrix to transform the peripheral cutting edge coordinate system to the workpiece coordinate system; the peripheral cutting edge coordinate system is established with the cutting edge point of the peripheral cutting edge spiral cutting edge function as the origin; the workpiece coordinate system is established with the tool rotation axis as one of the coordinate axes.

[0057] The peripheral cutting edge coordinate system is established with the cutting edge point on the peripheral cutting edge spiral cutting edge function as its origin, and the direction of one coordinate axis in the peripheral cutting edge coordinate system is the same as the direction of the tool rotation axis. The workpiece coordinate system has the tool rotation axis as one of its coordinate axes, and its origin can be located at the top of the tool blank.

[0058] Specifically, the CNC machine rotates and translates the peripheral coordinate system to obtain the workpiece coordinate system, and obtains the transformation matrix. This transformation matrix includes the rotation matrix and the translation matrix.

[0059] Step 606: Based on the transformation matrix and the initial grinding wheel position in the peripheral coordinate system, perform coordinate system transformation to obtain the target grinding wheel grinding trajectory in the workpiece coordinate system.

[0060] The initial grinding wheel position is the point where the edge of the grinding wheel touches the helical cutting edge function of the peripheral cutting edge, and satisfies the target radius rake angle and the target helix angle. The initial grinding wheel position can be a specific location. The target grinding wheel grinding trajectory contains a series of tool position coordinates.

[0061] Specifically, based on the transformation matrix, the CNC machine performs rotational and translational transformations on the initial grinding wheel position in the peripheral cutting edge coordinate system to obtain the target grinding wheel grinding trajectory in the workpiece coordinate system. Since the transformation matrix contains the cutting edge points of the peripheral cutting edge spiral cutting edge function, that is, it contains variables, and these variables are in the transformation matrix; therefore, by performing coordinate transformation, the grinding wheel position corresponding to each cutting edge point in the workpiece coordinate system can be obtained, thereby obtaining the target grinding wheel grinding trajectory in the workpiece coordinate system.

[0062] Step 608: Based on the transformation matrix and the initial grinding wheel axis vector in the peripheral coordinate system, perform coordinate system transformation to obtain the target grinding wheel axis vector in the workpiece coordinate system.

[0063] The target grinding wheel axis vector is a vector perpendicular to the end face of the grinding wheel. The end face of the grinding wheel is the circular surface (toroidal surface) of the grinding wheel. Preferably, the grinding wheel axis vector can be the vector of the grinding wheel axis center. The initial grinding wheel axis vector is the vector when the edge of the grinding wheel touches a point on the peripheral helical cutting edge function and satisfies the target arc back angle and the target helix angle. The initial grinding wheel axis vector can be a specific position.

[0064] Specifically, based on the transformation matrix, the CNC machine rotates the initial grinding wheel axis vector in the peripheral cutting edge coordinate system to obtain the target grinding wheel axis vector in the workpiece coordinate system. Similarly, since the transformation matrix contains the cutting edge points of the peripheral cutting edge spiral cutting edge function, that is, it contains variables, and these variables are in the transformation matrix; therefore, by performing coordinate transformation, the grinding wheel axis vector corresponding to each cutting edge point in the workpiece coordinate system can be obtained.

[0065] Step 610: Perform eccentric peripheral cutting face grinding based on the target grinding wheel grinding trajectory and the target grinding wheel axis vector.

[0066] Specifically, the CNC machine can determine the workpiece coordinate system by detecting the origin of the workpiece coordinate system and determining the tool rotation axis by positioning the tool. Under the workpiece coordinate system, the CNC machine controls the grinding wheel to perform peripheral cutting face grinding based on the target grinding wheel grinding trajectory and the target grinding wheel axis vector.

[0067] In this embodiment, a peripheral coordinate system is established with the cutting edge point of the peripheral helical cutter as the origin, and a workpiece coordinate system is established with the tool rotation axis as one of the coordinate axes. Since it is difficult for a CNC machine to perform tool grinding in the peripheral coordinate system, a transformation matrix is ​​obtained to transform the peripheral coordinate system to the workpiece coordinate system. The transformation matrix contains variables related to the cutting edge point. Therefore, the initial grinding wheel axis vector can be transformed into a coordinate system based on the transformation matrix. The target grinding wheel grinding trajectory and the target grinding wheel axis vector are obtained by performing a coordinate system transformation on the initial grinding wheel axis vector, so that the CNC machine can perform eccentric peripheral flank grinding in the workpiece coordinate system. This facilitates the post-processing to obtain the motion of each feed axis of the five-axis CNC tool grinder. The obtained eccentric peripheral flank has a large tool tip angle, high tool edge strength, and good cutting performance and surface quality.

[0068] In one embodiment, the peripheral spiral cutting edge line function is determined based on the tool rotation angle and rotation radius variables; both the tool rotation angle and rotation radius are variables whose values ​​change along the tool rotation axis.

[0069] The peripheral spiral cutting edge line can be viewed as the trajectory curve formed by a moving point P on the surface of the rotating tool, spiraling from the starting end face to the ending end face according to a specific law. For example... Figure 3 As shown, project any point on the helical blade onto X. w O w Z wIn a plane, relative to X w The included angle of the shaft is set as the tool rotation angle. Let the rotation angle at the starting point of the helical cutting edge be the initial rotation angle. The change in rotation angle of a moving point P relative to its initial position when it moves to any position on the cutting edge is: If this change is expressed with the z-coordinate as the independent variable, then the tool rotation angle of the moving point P is: Let the radius of rotation at the moving point P be R. (z) This change also takes the z-coordinate as its independent variable. The actual rotation angle of a tool with a constant helix angle cutting edge. and R (z) The formula is as follows:

[0070]

[0071] R (z) =R w +z·tank,-L w ≤z≤0

[0072] We can obtain the cutting edge point P on the peripheral edge in the workpiece coordinate system O. w -X w Y w Z w The coordinates are

[0073]

[0074] In this embodiment, a peripheral spiral cutting edge line function is constructed by using tool rotation angle and rotation radius variables. Both tool rotation angle and rotation radius are variables with values ​​taken on the tool rotation axis. This allows for the determination of grinding posture in conjunction with the cutting edge line, making calculation convenient and improving processing speed.

[0075] In one embodiment, the initial grinding wheel position is determined based on the end face radius and the grinding wheel tilt angle; the initial grinding wheel axis vector is determined based on the grinding wheel tilt angle.

[0076] Here, the z-axis is the direction of the tool's rotation axis, and the grinding wheel tilt angle is the angle between the projection of the grinding wheel's side surface onto the XZ plane and the X-axis in the peripheral cutting coordinate system.

[0077] Specifically, such as Figure 7 The diagram shows the initial grinding posture of the grinding wheel in one embodiment. The peripherally oriented eccentric flank face is ground using a 1A1 parallel grinding wheel. The initial grinding wheel posture during grinding the flank face is as follows: Figure 4 As shown. Based on the grinding principle of the eccentric relief face of the grinding wheel, the center O of the grinding wheel is set... g In plane X m Z m Inside, define the end face of the grinding wheel in plane X. m Z m Projection within and Xm The included angle between the axes is θ, called the grinding wheel tilt angle. Therefore, in the peripheral coordinate system, the initial grinding wheel position O g_m The coordinates can be expressed as:

[0078] Where R g End face radius

[0079] Its initial grinding wheel axis vector F g_m This can be expressed as:

[0080]

[0081] It is understandable that, given a fixed grinding wheel tilt angle and end face radius, the initial grinding wheel position and initial grinding wheel axis vector are constants.

[0082] In this embodiment, the initial grinding wheel position is determined based on the end face radius and the grinding wheel tilt angle, and the initial grinding wheel axis vector is determined based on the grinding wheel tilt angle. Coordinate transformation is performed based on constants to obtain the target grinding wheel grinding trajectory and the target grinding wheel axis vector in the workpiece coordinate system, thus obtaining an accurate grinding posture. The CNC machine can perform grinding based on this, thereby improving the surface quality of the machined object.

[0083] In one embodiment, the grinding wheel tilt angle is determined based on the rake face radius and the helix angle.

[0084] Specifically, such as Figure 8 The figure shown is a schematic diagram of the calculation model for the grinding wheel tilt angle in one embodiment. Figure 8 The right-middle image is a schematic diagram of the cutting tool. The cutting edge line is the circumferential helical cutting edge line; the flank face is the tool face formed after grinding based on this cutting edge line; the contact line is the contact line between the grinding wheel and the flank face. The cylindrical surface is the cylindrical surface of the cutting tool.

[0085] AB is the helical cutting edge line, BC is the contact line between the grinding wheel and the flank face, AC is the cross-sectional line of the flank face, and AD is the cross-sectional line of the cylindrical face. Based on geometric relationships, we can obtain:

[0086] CD = BD·tanθ

[0087] AD = BD · tanβ

[0088] tanα=CD / AD

[0089] Combining the above three equations, the grinding wheel tilt angle can be obtained as follows:

[0090] θ=tan -1 (tanα·tanβ)

[0091] From the above formula, we can see that the grinding wheel tilt angle θ is only related to the back arc angle α of the back face and the helix angle β.

[0092] Understandable, Figure 7 and Figure 8 The wheel inclination angle is a crucial grinding parameter in eccentric flank grinding. It affects not only the initial wheel position and axis vector but also the final grinding trajectory and axis vector. Furthermore, analysis shows that calculating this wheel inclination angle allows for the acquisition of a wheel posture that conforms to the rake face radius and helix angle, thus yielding a grinding trajectory and wheel posture suitable for eccentric flank grinding.

[0093] In one embodiment, the transformation matrix includes a rotation matrix and a translation matrix; the rotation matrix is ​​obtained by rotating the peripheral coordinate system about the tool rotation axis by a rotation angle; the translation matrix is ​​obtained by translating the peripheral coordinate system.

[0094] Specifically, the Zhouren coordinate system O m -X m Y m Z m Around Z m Axis rotation Angle, then translation to obtain the workpiece coordinate system O w -X w Y w Z w Therefore, the coordinate system O of the flank face of the cutting edge is... m -X m Y m Z m To the workpiece coordinate system O w -X w Y w Z w rotation matrix R m-w for

[0095]

[0096] Translation matrix T m-w for

[0097]

[0098] It can be seen that the rotation matrix and translation matrix mentioned above both use the tool rotation angle as a variable, while the tool rotation angle uses the value on the tool rotation axis as a variable.

[0099] In this embodiment, the transformation matrix includes a rotation matrix and a translation matrix. The rotation matrix is ​​obtained by rotating the tool rotation angle around the tool rotation axis in the peripheral coordinate system, and the translation matrix is ​​obtained by translating the peripheral coordinate system. This can convert the pose in the peripheral coordinate system into the pose in the workpiece coordinate system, so that the CNC machine can perform grinding of the eccentric back face based on this.

[0100] In one embodiment, a coordinate system transformation is performed based on the transformation matrix and the initial grinding wheel position in the peripheral coordinate system to obtain the target grinding wheel trajectory in the workpiece coordinate system, including:

[0101] Based on the product of the initial grinding wheel position and the rotation matrix in the peripheral coordinate system, and the sum of the translation matrix, the target grinding wheel grinding trajectory in the workpiece coordinate system is obtained.

[0102] Based on the transformation matrix and the initial grinding wheel axis vector in the peripheral coordinate system, a coordinate system transformation is performed to obtain the target grinding wheel axis vector in the workpiece coordinate system, including:

[0103] The target grinding wheel axis vector in the workpiece coordinate system is obtained by multiplying the initial grinding wheel axis vector in the peripheral coordinate system with the rotation matrix.

[0104] Specifically, the initial grinding wheel position O g_m With rotation matrix R m-w The product of the translation matrix T and the product of the translation matrix T m-w The sum of these values ​​yields the target grinding wheel trajectory O in the workpiece coordinate system. g_w :

[0105] O g_w =R m-w O g_m +T m-w

[0106] The product of the initial grinding wheel axis vector in the peripheral coordinate system and the rotation matrix yields the target grinding wheel axis vector F in the workpiece coordinate system. g_w :

[0107] F g_w =R m-w F g_m

[0108] In this embodiment, the grinding trajectory of the target grinding wheel in the workpiece coordinate system is obtained by multiplying the initial grinding wheel position in the peripheral coordinate system with the rotation matrix and the translation matrix. The target grinding wheel axis vector in the workpiece coordinate system is obtained by multiplying the initial grinding wheel axis vector in the peripheral coordinate system with the rotation matrix. This facilitates post-processing to obtain the motion of each feed axis of the five-axis CNC tool grinder and the grinding wheel orientation.

[0109] In one embodiment, a coordinate system transformation is performed based on a transformation matrix and an initial grinding wheel axis vector in the peripheral coordinate system to obtain a grinding wheel axis vector in the workpiece coordinate system. This includes: obtaining an end face radius vector; determining the end face radius vector based on the grinding wheel tilt angle; and rotating the initial grinding wheel axis vector around the end face radius vector by a preset swing angle to obtain the grinding wheel axis vector in the workpiece coordinate system.

[0110] Wherein, the swing angle μ is defined as the radius vector F of the grinding wheel around the end face of the grinding wheel.b The angle of rotation. One end of the end face radius vector is at the cutting edge point, and the other end is at the grinding wheel position. For example... Figure 7 As shown, the end face radius vector F of the grinding wheel can be easily obtained. b for:

[0111]

[0112] Given a vector revolving around any unit vector N (N x N y N z The general formula for the rotation matrix of rotation angle γ is:

[0113]

[0114] Where v ers γ = 1 - cosγ.

[0115] After adding the swing angle, the initial grinding wheel axis vector is rotated around the end face radius vector by a preset swing angle to obtain the transformed grinding wheel axis vector F′. g_m :

[0116] F′ g_m =rot(F b ,μ)×F g_m

[0117] The target grinding wheel vector F in the workpiece coordinate system is obtained by multiplying the transformed grinding wheel axis vector and rotation vector. g_w :

[0118] F g_w =R m-w F′ g_m

[0119] In this embodiment, the grinding wheel tilt angle process parameter is introduced into the coordinate system of the peripheral cutting edge face, and the target grinding wheel axis vector in the workpiece coordinate system is calculated accordingly. This can avoid the interference of the grinding wheel on the adjacent tooth feature structure that may occur during the grinding process.

[0120] In one embodiment, a grinding method for an eccentric peripheral cutting edge rake face includes:

[0121] Step (a1) obtains the peripheral spiral cutting edge line function; the peripheral spiral cutting edge line function is determined based on the tool rotation angle and rotation radius; the tool rotation angle and rotation radius are both variables with the values ​​on the tool rotation axis.

[0122] Step (a2) is to obtain the transformation matrix that transforms the peripheral cutting edge coordinate system to the workpiece coordinate system; the peripheral cutting edge coordinate system is established with the cutting edge point of the peripheral cutting edge spiral cutting edge function as the origin; the workpiece coordinate system is established with the tool rotation axis as one of the coordinate axes.

[0123] Step (a3) ​​is to obtain the target grinding wheel trajectory in the workpiece coordinate system based on the product of the initial grinding wheel position and the rotation matrix in the peripheral coordinate system and the sum of the translation matrix; the initial grinding wheel position is determined based on the end face radius and the grinding wheel tilt angle; the initial grinding wheel axis vector is determined based on the grinding wheel tilt angle; the grinding wheel tilt angle is determined based on the back arc angle and the helix angle of the flank face.

[0124] Step (a4): Obtain the end face radius vector; the end face radius vector is determined based on the grinding wheel tilt angle.

[0125] Step (a5) involves rotating the initial grinding wheel axis vector around the end face radius vector by a preset swing angle to obtain the transformed grinding wheel axis vector.

[0126] Step (a6) is to obtain the target grinding wheel axis vector in the workpiece coordinate system based on the product of the transformed grinding wheel axis vector and the rotation vector.

[0127] Step (a7) involves grinding the eccentric peripheral cutting edge face based on the target grinding wheel's grinding trajectory and the target grinding wheel's axis vector.

[0128] This embodiment provides a method for calculating the grinding trajectory of an eccentric peripheral cutting edge rake face. First, the structural parameters of the eccentric peripheral cutting edge rake face are defined, and a coordinate system for the peripheral cutting edge rake face and a workpiece coordinate system following the peripheral cutting edge helical cutting line are established. Second, the angle of the grinding wheel during grinding is calculated based on the grinding principle and tool parameters, thereby determining the grinding posture of the grinding wheel. Then, the grinding wheel tool position coordinates in the workpiece coordinate system are derived and calculated through coordinate transformation matrices and kinematic principles. Finally, the accuracy and effectiveness of the eccentric peripheral cutting edge rake face are verified through simulation. The eccentric peripheral cutting edge rake face obtained by this method has a large tool tip angle, high tool edge strength, good cutting performance, and good surface finish. Furthermore, the introduction of the grinding wheel tilt angle process parameter can avoid interference of the grinding wheel with adjacent tooth features during the grinding process.

[0129] In one embodiment, to verify the eccentric peripheral cutting edge face grinding pose algorithm proposed in various embodiments of this application, this paper uses a 6mm diameter three-flute end mill as the research and verification object, and grinds it with a 6mm thick 1A1 flat grinding wheel. The design values ​​of the main tool structure parameters and the measured values ​​of the simulation results are shown in Table 1. The error values ​​of each item in Table 1 are all low, which is significantly lower than the error values ​​of traditional methods.

[0130] The calculation results of some grinding trajectories are shown in Table 2, and the results of grinding simulation are shown in Table 3. Figure 9 As shown. Figure 9 This is a schematic diagram of the grinding result of an eccentric flank face in one embodiment. 902 is the eccentric peripheral flank face. Figure 9 The left image is a 3D view of the cutting tool, and the right image is a projection view of the cutting tool in the XY plane. Figure 9The arc shape of the blade in the middle right image indicates that it is an eccentric blade.

[0131] Table 1

[0132]

[0133] Table 2

[0134]

[0135]

[0136] Measurement and simulation results show that the grinding algorithm for the eccentric circumferential cutting edge face proposed in the various embodiments of this application can basically meet the design and machining requirements of the eccentric circumferential cutting edge face.

[0137] It should be understood that, although the above Figure 6 In the flowchart, the steps are shown sequentially according to the arrows, and the steps (a1) through (a7) are shown sequentially according to their numbers. However, these steps are not necessarily executed in the order indicated by the arrows or numbers. Unless explicitly stated herein, there is no strict order requirement for the execution of these steps; they can be executed in other orders. Figure 6 At least some of the steps in the process may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but may be executed at different times. The execution order of these steps or stages is not necessarily sequential, but may be executed in turn or alternately with other steps or at least some of the steps or stages in other steps.

[0138] In one embodiment, such as Figure 10 The figure shown is a structural block diagram of a grinding device for an eccentric peripheral cutting edge in one embodiment. Figure 10 A grinding device for an eccentric peripheral cutting edge is provided. This device can be a software module, a hardware module, or a combination of both, integrated into a CNC machine. Specifically, the device includes: a function acquisition module 1002, a transformation matrix acquisition module 1004, a trajectory determination module 1006, a grinding wheel axis vector determination module 1008, and a grinding module 1010, wherein:

[0139] Function acquisition module 1002 is used to acquire the peripheral spiral cutting edge line function;

[0140] The transformation matrix acquisition module 1004 is used to acquire the transformation matrix for transforming the peripheral cutting edge coordinate system to the workpiece coordinate system; the peripheral cutting edge coordinate system is established with the cutting edge point of the peripheral cutting edge spiral cutting edge function as the origin; the workpiece coordinate system is established with the tool rotation axis as one of the coordinate axes.

[0141] The trajectory determination module 1006 is used to perform coordinate system transformation based on the transformation matrix and the initial grinding wheel position in the peripheral coordinate system to obtain the target grinding wheel grinding trajectory in the workpiece coordinate system.

[0142] The grinding wheel axis vector determination module 1008 is used to perform coordinate system transformation based on the transformation matrix and the initial grinding wheel axis vector in the peripheral cutting edge coordinate system to obtain the target grinding wheel axis vector in the workpiece coordinate system.

[0143] Grinding module 1010 is used for grinding the eccentric peripheral cutting face based on the grinding trajectory of the target grinding wheel and the axis vector of the target grinding wheel.

[0144] In this embodiment, a peripheral coordinate system is established with the cutting edge point of the peripheral helical cutter as the origin, and a workpiece coordinate system is established with the tool rotation axis as one of the coordinate axes. Since it is difficult for a CNC machine to perform tool grinding in the peripheral coordinate system, a transformation matrix is ​​obtained to transform the peripheral coordinate system to the workpiece coordinate system. The transformation matrix contains variables related to the cutting edge point. Therefore, the initial grinding wheel axis vector can be transformed into a coordinate system based on the transformation matrix. By transforming the initial grinding wheel axis vector into a coordinate system, the target grinding wheel grinding trajectory and the target grinding wheel axis vector can be obtained, so that the CNC machine can perform eccentric peripheral flank grinding in the workpiece coordinate system. The obtained eccentric peripheral flank has a large tool tip angle, high tool edge strength, and good cutting performance and surface quality.

[0145] In one embodiment, the peripheral spiral cutting edge line function is determined based on the tool rotation angle and rotation radius variables; both the tool rotation angle and rotation radius are variables whose values ​​change along the tool rotation axis.

[0146] In this embodiment, a peripheral spiral cutting edge line function is constructed by using tool rotation angle and rotation radius variables. Both tool rotation angle and rotation radius are variables with values ​​taken on the tool rotation axis. This allows for the determination of grinding posture in conjunction with the cutting edge line, making calculation convenient and improving processing speed.

[0147] In one embodiment, the initial grinding wheel position is determined based on the end face radius and the grinding wheel tilt angle; the initial grinding wheel axis vector is determined based on the grinding wheel tilt angle.

[0148] In this embodiment, the initial grinding wheel position is determined based on the end face radius and the grinding wheel tilt angle, and the initial grinding wheel axis vector is determined based on the grinding wheel tilt angle. Coordinate transformation is performed based on constants to obtain the target grinding wheel grinding trajectory and the target grinding wheel axis vector in the workpiece coordinate system, thus obtaining an accurate grinding posture. The CNC machine can perform grinding based on this, thereby improving the surface quality of the machined object.

[0149] In one embodiment, the grinding wheel tilt angle is determined based on the rake face radius and helix angle. In this embodiment, through analysis, the grinding wheel tilt angle can be calculated to obtain a grinding wheel posture that conforms to the rake face radius and helix angle, thereby obtaining a grinding trajectory and grinding wheel posture that conforms to eccentric rake face grinding.

[0150] In one embodiment, the transformation matrix includes a rotation matrix and a translation matrix; the rotation matrix is ​​obtained by rotating the peripheral coordinate system about the tool rotation axis by a rotation angle; the translation matrix is ​​obtained by translating the peripheral coordinate system.

[0151] In this embodiment, the transformation matrix includes a rotation matrix and a translation matrix. The rotation matrix is ​​obtained by rotating the tool rotation angle around the tool rotation axis in the peripheral coordinate system, and the translation matrix is ​​obtained by translating the peripheral coordinate system. This can convert the pose in the peripheral coordinate system into the pose in the workpiece coordinate system, so that the CNC machine can perform grinding of the eccentric back face based on this.

[0152] In one embodiment, the trajectory determination module 1006 is used to obtain the target grinding trajectory of the grinding wheel in the workpiece coordinate system based on the product of the initial grinding wheel position in the peripheral coordinate system and the rotation matrix, and the sum of the translation matrix.

[0153] The grinding wheel axis vector determination module 1008 is used to obtain the target grinding wheel axis vector in the workpiece coordinate system based on the product of the initial grinding wheel axis vector in the peripheral coordinate system and the rotation matrix.

[0154] In this embodiment, the grinding trajectory of the target grinding wheel in the workpiece coordinate system is obtained by multiplying the initial grinding wheel position in the peripheral coordinate system with the rotation matrix and the translation matrix. The target grinding wheel axis vector in the workpiece coordinate system is obtained by multiplying the initial grinding wheel axis vector in the peripheral coordinate system with the rotation matrix. This facilitates post-processing to obtain the motion of each feed axis of the five-axis CNC tool grinder and the grinding wheel orientation.

[0155] In one embodiment, the grinding wheel axis vector determination module 1008 is used to obtain the end face radius vector; the end face radius vector is determined based on the grinding wheel tilt angle; the initial grinding wheel axis vector is rotated around the end face radius vector by a preset swing angle to obtain the grinding wheel axis vector in the workpiece coordinate system.

[0156] In this embodiment, the grinding wheel tilt angle process parameter is introduced into the coordinate system of the peripheral cutting edge face, and the target grinding wheel axis vector in the workpiece coordinate system is calculated accordingly. This can avoid the interference of the grinding wheel on the adjacent tooth feature structure that may occur during the grinding process.

[0157] Specific limitations regarding the grinding device for eccentric peripheral cutting edges can be found in the above description of the grinding method for eccentric peripheral cutting edges, and will not be repeated here. Each module in the aforementioned grinding device for eccentric peripheral cutting edges can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the CNC machine's processor in hardware form or independent of it, or stored in the CNC machine's memory in software form, so that the processor can call and execute the corresponding operations of each module.

[0158] In one embodiment, a CNC machine is provided, which may be a terminal device, and its internal structure diagram may be as follows: Figure 11 As shown, the CNC machine includes a processor, memory, communication interface, display screen, and input devices connected via a system bus. The processor provides computational and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage medium. The communication interface allows for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, carrier networks, NFC (Near Field Communication), or other technologies. When executed by the processor, the computer program implements a grinding method for an eccentric circumferential cutting edge. The display screen can be an LCD screen or an e-ink screen. The input devices can be a touch layer covering the display screen, buttons, a trackball, or a touchpad on the CNC machine casing, or an external keyboard, touchpad, or mouse.

[0159] Those skilled in the art will understand that Figure 11 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the CNC machine to which the present application is applied. A specific CNC machine may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0160] In one embodiment, a numerical control machine is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the above-described method embodiments.

[0161] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described method embodiments.

[0162] In one embodiment, a computer program product or computer program is provided, comprising computer instructions stored in a computer-readable storage medium. The processor of a CNC machine reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the CNC machine to perform the steps described in the above method embodiments.

[0163] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. This computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes described in the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, or optical storage, etc. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0164] The above description is only a preferred embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural changes made based on the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A grinding method for the eccentric peripheral cutting edge rake face, characterized in that, The method includes: Obtain the peripheral spiral cutting edge function; the peripheral spiral cutting edge function is determined based on the tool rotation angle and the radius of rotation; both the tool rotation angle and the radius of rotation are variables with values ​​on the tool rotation axis; the peripheral spiral cutting edge function includes the inverted taper angle k, and the radius of rotation R(z) varies linearly with the axial coordinate z. Rw is the initial rotation radius of the tool; Obtain the transformation matrix to transform the peripheral cutting edge coordinate system to the workpiece coordinate system; the peripheral cutting edge coordinate system is established with the cutting edge point of the peripheral cutting edge spiral cutting edge function as the origin; the workpiece coordinate system is established with the tool rotation axis as one of the coordinate axes; the transformation matrix includes a rotation matrix and a translation matrix; the rotation matrix is ​​obtained by rotating the peripheral cutting edge coordinate system around the tool rotation axis by the tool rotation angle; the translation matrix is ​​obtained by translating the peripheral cutting edge coordinate system; The target grinding wheel trajectory in the workpiece coordinate system is obtained by multiplying the initial grinding wheel position in the peripheral coordinate system by the rotation matrix and the translation matrix. The initial grinding wheel position is determined based on the end face radius and the grinding wheel tilt angle. The grinding wheel tilt angle θ is determined based on the rake face radius α and the helix angle β, and satisfies the following conditions: ; Obtain the end face radius vector; the end face radius vector is determined based on the grinding wheel tilt angle; The initial grinding wheel axis vector in the peripheral coordinate system is rotated around the end face radius vector by a preset swing angle to obtain the transformed grinding wheel axis vector; the initial grinding wheel axis vector is determined based on the grinding wheel tilt angle. Based on the product of the transformed grinding wheel axis vector and the rotation matrix, the target grinding wheel axis vector in the workpiece coordinate system is obtained; Eccentric peripheral cutting face grinding is performed based on the target grinding wheel grinding trajectory and the target grinding wheel axis vector.

2. A grinding device for an eccentric peripheral cutting edge rear face, characterized in that, The apparatus is used to implement the method of claim 1, comprising: The function acquisition module is used to obtain the peripheral spiral cutting edge line function; the peripheral spiral cutting edge line function is determined based on the tool rotation angle and the rotation radius; both the tool rotation angle and the rotation radius are variables with values ​​on the tool rotation axis; the peripheral spiral cutting edge line function includes the inverted taper angle k, and the rotation radius R(z) varies linearly with the axial coordinate z. The initial rotation radius of the tool; A transformation matrix acquisition module is used to acquire a transformation matrix that transforms the peripheral cutting edge coordinate system to the workpiece coordinate system. The peripheral cutting edge coordinate system is established with the cutting edge point of the peripheral cutting edge spiral cutting edge function as the origin. The workpiece coordinate system is established with the tool rotation axis as one of the coordinate axes. The transformation matrix includes a rotation matrix and a translation matrix. The rotation matrix is ​​obtained by rotating the peripheral cutting edge coordinate system around the tool rotation axis by the tool rotation angle. The translation matrix is ​​obtained by translating the peripheral cutting edge coordinate system. The trajectory determination module is used to obtain the target grinding trajectory of the grinding wheel in the workpiece coordinate system based on the product of the initial grinding wheel position in the peripheral cutting edge coordinate system and the rotation matrix, and the sum of the translation matrix; the initial grinding wheel position is determined based on the end face radius and the grinding wheel tilt angle; the grinding wheel tilt angle θ is determined based on the rake face radius α and the helix angle β, and satisfies... ; The grinding wheel axis vector determination module is used for: Obtain the end face radius vector; the end face radius vector is determined based on the grinding wheel tilt angle; The initial grinding wheel axis vector in the peripheral coordinate system is rotated around the end face radius vector by a preset swing angle to obtain the transformed grinding wheel axis vector; the initial grinding wheel axis vector is determined based on the grinding wheel tilt angle. Based on the product of the transformed grinding wheel axis vector and the rotation matrix, the target grinding wheel axis vector in the workpiece coordinate system is obtained; The grinding module is used to perform eccentric peripheral cutting face grinding based on the grinding trajectory of the target grinding wheel and the axis vector of the target grinding wheel.

3. A numerical control machine, comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method of claim 1.

4. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the method of claim 1.

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