Method and device for grinding stepped surface of tool, numerical control machine and storage medium

Abstract

The application relates to a stepped curved surface grinding method and device of a tool, a numerical control machine and a storage medium. The method comprises the following steps: acquiring a target generatrix vector corresponding to a point on a reference alignment line of a stepped curved surface; offsetting the point on the reference alignment line by a distance corresponding to a preset relief angle along a preset direction to obtain a point on a target alignment line; determining a grinding point located on the target generatrix vector based on the point on the target alignment line to obtain a grinding track; and grinding the stepped curved surface of a workpiece to be processed based on the grinding track. The method can simplify the track calculation process and improve the grinding efficiency.

Description

Technical Field

[0001] This application relates to the field of computer technology, and in particular to a method, apparatus, CNC machine, and storage medium for grinding stepped curved surfaces of cutting tools. Background Technology

[0002] Step drills are commonly used drilling tools, offering the advantage of replacing multiple drill bits with a single drill bit, thus improving drilling efficiency. Their structure typically consists of a drill tip, spiral flutes, a cylindrical cutting edge, and a stepped surface. The stepped surface significantly influences tool performance, including cutting forces and chip flow direction during drilling. Traditional grinding of stepped surfaces involves cumbersome trajectory calculations, leading to low grinding efficiency. Summary of the Invention

[0003] Therefore, it is necessary to provide a method, apparatus, CNC machine, and storage medium for grinding stepped curved surfaces of cutting tools to address the above-mentioned technical problems, which can simplify the trajectory calculation process and improve grinding efficiency.

[0004] A method for grinding stepped curved surfaces of a cutting tool, the method comprising:

[0005] Obtain the target generatrix vector corresponding to the point on the reference directrix of the stepped surface;

[0006] The point on the reference guideline is offset along a preset direction by a distance corresponding to a preset rear angle to obtain the point on the target guideline;

[0007] Based on the points on the target standard line, determine the grinding points located on the corresponding target generatrix vector to obtain the grinding trajectory;

[0008] The stepped surface of the workpiece is ground based on the grinding trajectory.

[0009] A stepped surface grinding apparatus for cutting tools, the apparatus being used to implement the steps of an embodiment of a stepped surface grinding method for each cutting tool.

[0010] 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 step surface grinding method for each tool.

[0011] A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of an embodiment of a step surface grinding method for various cutting tools.

[0012] The aforementioned method, apparatus, CNC machine, and storage medium for grinding stepped surfaces of cutting tools allow the stepped surface to be viewed as points on a guideline where generatrices are distributed. Furthermore, the direction of these generatrices remains unchanged regardless of various deviations of the guideline, thus, for stepped surfaces under different conditions, the target generatrice vector corresponding to a point on the reference guideline of the same stepped surface can be obtained. The points on the reference guideline are offset along a preset direction by a distance corresponding to a preset back angle to obtain points on the target guideline. Based on these points, the grinding point located on the corresponding target generatrice vector is determined, thus obtaining the grinding trajectory. This is derived from an ideal frustum surface, utilizing the idea of ​​multiple generatrices distributed on the guideline. The points on the reference guideline are offset by a distance corresponding to a preset back angle to meet the back angle control requirements in the process, simplifying trajectory calculation and enabling rapid grinding of stepped surfaces. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of a stepped surface and its corresponding coordinate system in one embodiment;

[0014] Figure 2 This is a schematic flowchart of a stepped surface grinding method for a cutting tool in one embodiment;

[0015] Figure 3 This is a schematic diagram of the axial clearance angle of the tool in one embodiment;

[0016] Figure 4 This is a schematic diagram of the radial clearance angle of the tool in one embodiment;

[0017] Figure 5 This is an internal structural diagram of a CNC machine in one embodiment. Detailed Implementation

[0018] It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0019] 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.

[0020] 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.

[0021] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. If the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed in this application.

[0022] 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.

[0023] The stepped surface grinding method for cutting tools provided in this application can be applied to, for example... Figure 1 In the application environment. Figure 1 This diagram illustrates the application environment of a stepped surface grinding method for a cutting tool in one embodiment. The terminal device can be, but is not limited to, various personal computers, laptops, smartphones, tablets, and portable wearable devices. The server can be a standalone server or a server cluster consisting of multiple servers.

[0024] In one embodiment, the stepped surface can be the side surface of a frustum, which can be viewed as a set of straight lines distributed along a fixed path point. The taper angle characterizes the inclination angle of the frustum surface. In tool design, controlling the preset clearance angles of the tool, such as the radial clearance angle and the axial clearance angle, is paramount. For ease of description, a coordinate system is established, such as... Figure 1 As shown, Figure 1 This is a schematic diagram of a stepped surface and its corresponding coordinate system in one embodiment. The origin O is at the center of the end face of the stepped frustum (reference plane), the Z-axis is the tool axis, the Z-axis direction is the tool axial direction, and the XY plane is parallel to the end face of the stepped cylinder. Figure 1 The relevant parameters include: taper angle δ, angle parameter θ = n * θs (where the angle step is θs, n represents the number of points, i.e., the nth point, and the product of the two is the rotation angle θ; it can be understood that θ, n, and θs are all angle parameters), and small end cylinder radius R1; in addition, the grinding wheel parameters include: grinding wheel radius G. r The angle parameter θ is the angle between the point P on the XY plane directrix trajectory and the X-axis. The stepped surface grinding method in this embodiment can be applied to CNC machines, tool grinding machines, etc.

[0025] In one embodiment, such as Figure 2The diagram shown is a flowchart illustrating a stepped surface grinding method for a cutting tool in one embodiment, taking its application to a CNC machine as an example. The method includes:

[0026] Step 202: Obtain the target generatrix vector corresponding to the point on the reference directrix of the stepped surface.

[0027] The directrix of the ideal frustum is called the reference directrix. The plane containing the reference directrix is ​​called the reference directrix plane. The reference directrix plane is perpendicular to the tool axis. Specifically, the reference directrix plane can be the end face of a stepped frustum.

[0028] Specifically, considering only the taper angle, the stepped surface is an ideal frustum side surface. The stepped surface can be viewed as a series of generatrices distributed at points on the directrix. The target generatrice vector is the vector represented by the generatrices of the stepped surface. The angle between the target generatrice vector and the tool axis is the taper angle. The target generatrice vector corresponding to a point on the reference directrix can be pre-stored in the CNC machine. The points on the reference directrix are determined by angle parameters.

[0029] Step 204: Offset the point on the reference line by a distance corresponding to the preset rear angle along the preset direction to obtain the point on the target line.

[0030] The preset clearance angle can be input by the user or a value preset in the CNC machine. The preset direction corresponds to the preset clearance angle. For example, if the preset clearance angle is axial, then the preset direction is the tool axis. If the preset clearance angle is radial, then the preset direction is the radial direction of the reference plane.

[0031] The preset direction indicates the direction in which a point on the reference headline is offset. The preset direction can include either the tool axis or the radial direction of the reference headline plane. The tool axis is the direction indicated by the tool's axis of rotation. The radial direction of the reference headline plane is the direction along the diameter or radius on the reference headline plane.

[0032] The preset clearance angle is the control angle of the cutting tool. The clearance angle of a stepped surface has a significant impact on tool performance, such as cutting force and chip flow direction during drilling. The preset clearance angle can include at least one of the axial clearance angle and the radial clearance angle. The axial clearance angle refers to the angle of change of a point on the reference line along the tool's axial direction.

[0033] Specifically, the CNC machine offsets the point on the reference guideline of the stepped surface by a distance corresponding to the preset back angle along a preset direction corresponding to the preset back angle, thereby obtaining the point on the target guideline.

[0034] Optionally, the CNC machine offsets the points on the reference guideline of the stepped surface along the tool axis by the axial distance corresponding to the axial back angle to obtain the points on the target guideline.

[0035] Optionally, the CNC machine offsets the point on the reference guideline of the stepped surface by the radial distance corresponding to the radial back angle along the radial direction of the reference plane to obtain the point on the target guideline.

[0036] Optionally, the CNC machine obtains the point on the target line by offsetting a point on the reference guideline of the stepped surface along the tool axis by the axial distance corresponding to the axial clearance angle, and by offsetting a point along the reference guideline plane by the radial distance corresponding to the radial clearance angle. The order of these two operations is not limited and can be implemented in either case.

[0037] Step 206: Based on the points on the target standard line, determine the grinding points located on the corresponding target generatrix vector to obtain the grinding trajectory.

[0038] The grinding trajectory is used to represent the movement trajectory of the grinding tool. For example, the grinding trajectory can be the trajectory of the center point of the grinding tool, or the trajectory of the position of a point on the edge of the grinding tool, etc., and is not limited to these.

[0039] Specifically, the CNC machine determines the grinding point located on the corresponding target generatrix vector based on a point on the target standard line, thus obtaining the grinding trajectory. That is, based on a point Pn'' on the target standard line, it determines the grinding point on the target generatrix vector Tn corresponding to point Pn'', thus obtaining the grinding trajectory. In other words, the grinding point lies in the direction represented by the target generatrix vector Tn corresponding to point Pn'' on the target standard line.

[0040] Step 208: Grind the stepped surface of the workpiece based on the grinding trajectory.

[0041] Specifically, the workpiece to be processed can be a tool blank, a worn tool, a cylindrical object, etc., but is not limited to these. The CNC machine controls the grinding tool to perform stepped surface grinding on the workpiece according to this grinding trajectory.

[0042] In this embodiment, the stepped surface can be regarded as a series of generatrices distributed on the points of the guideline. Under the requirements of the tool grinding scenario, the direction of the generatrices does not change due to various offsets of the guideline. Therefore, for stepped surfaces under different conditions, the target generatrice vector corresponding to the point on the reference guideline of the same stepped surface can be obtained. The point on the reference guideline is offset along the preset direction by a distance corresponding to a preset back angle to obtain the point on the target guideline. Based on the point on the target guideline, the grinding point located on the corresponding target generatrice vector is determined to obtain the grinding trajectory. That is, it is derived from the ideal frustum surface. By using the idea of ​​multiple generatrices distributed on the guideline, the point on the reference guideline is offset by a distance corresponding to a preset back angle to meet the back angle control in the process. This simplifies the trajectory calculation and quickly realizes the grinding of the stepped surface.

[0043] In one embodiment, obtaining the target generatrix vector corresponding to a point on the reference directrix of the stepped surface includes:

[0044] The initial generatrix vector representing the taper angle on the stepped surface is rotated around the tool axis by an angle parameter to obtain the target generatrix vector corresponding to the point on the reference line.

[0045] In this context, disregarding the axial clearance angle α1 and radial clearance angle α2, and considering only the taper angle, the stepped surface is an ideal frustum-shaped side surface. The stepped surface can be viewed as a series of generatrices distributed at points on the directrix. The target generatrice vector is the vector represented by the generatrices of the stepped surface. The angle between the target generatrice vector and the tool axis is the taper angle.

[0046] Specifically, in an ideal scenario, neglecting the back angle and only considering the taper angle, the stepped surface can be regarded as a frustum surface. In this case, the starting point is on the X-axis, and the sweep trajectory is the reference directrix, i.e., the arc of the frustum's end face. Therefore, the initial generatrix vector T0 is...

[0047]

[0048] Point Pn on the reference line corresponding to different angular parameters θ is

[0049]

[0050] Based on the rotation matrix corresponding to the angle parameter, the initial generatrix vector T0 is rotated around the tool axis by the angle parameter θ of point Pn on the reference headline to obtain the target generatrix vector Tn corresponding to point Pn on the reference headline:

[0051]

[0052] The matrix on the left side of the formula is a rotation matrix that rotates around the tool axis.

[0053] Since the direction of the generatrix vector remains unchanged after considering the rear angle, the expression of the target generatrix vector remains unchanged, and the target generatrix vector also corresponds to a point on the target generatrix.

[0054] In this embodiment, the stepped surface is regarded as the side of an ideal frustum, and the initial generatrix vector representing the taper angle on the stepped surface can be easily obtained. The initial generatrix vector is rotated around the tool axis to obtain the angle parameter corresponding to the point on the reference line, thereby obtaining the target generatrix vector corresponding to the point on the reference line. The calculation is simple and fast, which improves the tool grinding speed.

[0055] In one embodiment, the preset direction includes the tool axis; the preset clearance angle includes the axial clearance angle, which represents the angle of change of a point on the reference line along the tool axis.

[0056] The points on the reference line are offset along a preset direction by a distance corresponding to a preset rear angle to obtain the points on the target line, including:

[0057] The axial distance corresponding to the axial rear angle is determined based on the product of the angle parameter, the tangent of the axial rear angle, and the radius of the reference directrix plane.

[0058] The point on the reference line is offset axially along the tool axis by a distance to obtain the point on the target line.

[0059] Among them, such as Figure 3 The diagram shows a schematic of the tool axial clearance angle in one embodiment. The axial clearance angle α1 represents the angle of change of a point on the reference line along the tool axial direction. The axial clearance angle α1 can also be interpreted as the angle between the tangent vector of point Pn′ (i.e., on the target line in this embodiment) and the plane passing through point Pn on the reference line and parallel to the tool axis, after considering the axial clearance angle. Figure 3 The central directrix can be considered as a cylindrical helix, and the rear angle of the axis is complementary to the helix angle of the directrix. Figure 3 This includes point Pn on the nth reference line and point P on the (n-1)th reference line. n-1 Consider the nth point Pn′ after the axial rearward angle α1. As the value of the angle parameter increases, point Pn moves along the arc while simultaneously moving downwards along the axial direction by Z. n .

[0060] Therefore, it is necessary to determine the axial distance corresponding to the axial rearward angle in three-dimensional space. Thus, based on the product of the angle parameter θ, the radius R1 of the reference directrix plane, and the tangent of the axial rearward angle α1, the axial distance Z corresponding to the axial rearward angle α1 is determined. n Then there is

[0061] Z n =R1*(θs*n)*tanα1

[0062] The distance Pn moves on the plane passing through Pn and parallel to the tool axis is determined by the product of the radius R1 of the reference plane and the angle parameter (θ = θs * n); then multiplying by tanα1 gives the axial distance offset in the tool axis.

[0063] Then, the point Pn on the reference guideline is offset by the axial distance Z along the tool axis. n Obtain point Pn′ on the target standard line:

[0064]

[0065] In this embodiment, the axial distance corresponding to the axial rear angle is determined based on the product of the angle parameter, the tangent of the axial rear angle, and the radius of the reference plane. The point on the reference plane is offset along the tool axis by the axial distance to obtain the point on the target plane. The point on the helical line can be quickly obtained through the reference plane. The calculation is simple and meets the requirements, and the grinding speed is fast.

[0066] In one embodiment, the preset direction includes the radial direction of the reference guide plane; the preset rear angle includes a radial rear angle, which represents the angle of change of a point on the reference guide in the radial direction of the reference guide plane.

[0067] The points on the reference line are offset along a preset direction by a distance corresponding to a preset rear angle to obtain the points on the target line, including:

[0068] Obtain the radial vector corresponding to a point on the reference directrix on the reference directrix plane;

[0069] Based on the reference radius, angle parameters, and the tangent of the radial rear angle, determine the radial distance corresponding to the radial rear angle;

[0070] The point on the reference line is offset radially by a radial distance along the radial vector to obtain the point on the target line.

[0071] Among them, such as Figure 4 The diagram shows a schematic representation of the radial clearance angle of the tool in one embodiment. The radial clearance angle α2 represents the angle of change of a point on the reference line in the radial direction of the reference line plane. The radial clearance angle can also be expressed as the angle between the tangent vector of point Pn" on a plane passing through point Pn on the reference line and perpendicular to the tool axis and the initial point P0. Figure 4 This includes point P on the (n-1)th reference guideline. n-1 Let Pn be the point on the nth reference line after rotating θs, and Pn' be the point on the nth reference line after considering the radial rear angle α2. It is understandable that the radius corresponding to the points on the reference line is R1.

[0072] Obtain the radial vector Tr corresponding to point Pn on the reference directrix in the reference directrix plane. N :

[0073]

[0074] Where θ is the rotation angle corresponding to the current point Pn.

[0075] Point P on the reference directrix with the reference radius as the reference radius N The radius R1, which corresponds to the reference plane, will be used as an example for explanation. P N Pn" is the distance between point Pn on the reference line in the XY plane and the nth point Pn" after considering the radial angle α2, which is also the radial distance. Let the angle Pn"PnP n-1 If the angle is approximately right, then the following relationship holds:

[0076] Rp n =R1-P n Pn"

[0077] Among them, Rp n "is the radius corresponding to Pn".

[0078] The radial distance P is obtained based on the reference radius R1, the rotation angle θ of the point on the reference directrix, and the tangent of the radial rear angle α2. n Pn" is

[0079] P n Pn"=R1-R1*θ*tanα2

[0080] Finally, point Pn″ on the target standard line is

[0081] Pn"=P n -Trn*P n Pn"

[0082] In this embodiment, the radial vector corresponding to the point on the reference guideline is obtained on the reference guideline plane. Then, based on the reference radius, angle parameters and the tangent value of the radial clearance angle, the radial distance corresponding to the radial clearance angle is determined. The point on the reference guideline is offset along the radial vector by the radial distance to obtain the point on the target guideline. This allows for the grinding of a stepped surface that conforms to the radial clearance angle, thereby achieving tool performance control.

[0083] In one embodiment, the reference radius is the radius of a point on the previous target line; the angle parameter includes the angular step distance between the two points;

[0084] Based on the reference radius, angle parameters, and the tangent of the radial clearance angle, the radial distance corresponding to the radial clearance angle is determined, including:

[0085] The radius of the point on the current target line is obtained by multiplying the radius, angle layout, and tangent of the radial rear angle of the point on the previous target line.

[0086] Determine the difference between the radius of a point on the previous target line and the radius of a point on the current target line, and obtain the radial distance corresponding to the radial rear angle.

[0087] Specifically, point P on the previous target line is taken as the reference radius. n-1 "corresponding radius Rp n-1 Let's take an example to illustrate. Rp n-1 "For P" n-1 The radius corresponding to the point. Rp n "The radius corresponding to point Pn". n Pn" is the distance between point Pn on the reference line in the XY plane and the nth point Pn" after considering the radial angle α2, which is also the radial distance. Since the discrete angular step size θs is very small, the angle Pn"PnP n-1 If we can approximate it as a right angle, then we have the following relationship:

[0088] Rp n =Rp n-1 "-P n Pn″

[0089] Based on the reference radius R n-1 The radial distance P is obtained by taking the tangent of the angle parameter (angle step) θs and the radial back angle α2. n Pn" is

[0090] P n Pn"=Rp n-1 -Rp n-1 "*θs*tanα2

[0091] Finally, point Pn″ on the target standard line is

[0092] Pn″=P n -Trn*P n Pn″

[0093] By using the current Rp n "As Rp for the next calculation" n-1 ", and you will get the next Pn".

[0094] Understandable, Figure 4 P as represented in n-1 It is a starting point, with reference point P. n-1 Point P on the target line n-1 "If it is the same point, then point P on the previous reference line can be used." n-1 As a point on the previous target line.

[0095] In this embodiment, the arc length corresponding to the point after rotating around the tool axis by the angle step is calculated from the point on the previous target line, and is used as a reference value for the tangent side length. Since the angle step value is small, the radial distance is calculated through this short arc segment, and the error between the two points is not obvious. This can effectively prevent the error from increasing indefinitely, and the ground stepped surface is smoother.

[0096] In one embodiment, the preset direction includes the tool axis and the radial direction of the reference plane; the preset clearance angle includes an axial clearance angle and a radial clearance angle, wherein the axial clearance angle represents the angle of change of a point on the reference plane in the tool axis, and the radial clearance angle represents the angle of change of a point on the reference plane in the radial direction.

[0097] The points on the reference line are offset along a preset direction by a distance corresponding to a preset rear angle to obtain the points on the target line, including:

[0098] The point on the reference guideline is obtained by offsetting the point along the tool axis by the axial distance corresponding to the axial back angle, and by offsetting the point along the reference guideline plane by the radial distance corresponding to the radial back angle.

[0099] Specifically, the axial clearance angle represents the change along the tool axis, while the radial clearance angle represents the change in a plane perpendicular to the tool axis; the two do not affect each other. Therefore, the order of the axial distance offset along the tool axis corresponding to the axial clearance angle and the radial distance offset along the reference plane corresponding to the radial clearance angle is not important.

[0100] Optionally, a point on the reference guideline is offset along the tool axis by the axial distance corresponding to the axial clearance angle to obtain an axial offset point; the axial offset point is then offset along the reference guideline plane by the radial distance corresponding to the radial clearance angle to obtain a point on the target guideline.

[0101] Specifically, based on the product of the angle parameter, the tangent of the axial clearance angle, and the radius of the reference headline plane, the axial distance corresponding to the axial clearance angle is determined; the point on the reference headline is offset along the tool axis by the axial distance to obtain the axial offset point; the radial vector corresponding to the point on the reference headline plane is obtained; based on the reference radius, the angle parameter, and the tangent of the radial clearance angle, the radial distance corresponding to the radial clearance angle is determined; the axial offset point is offset along the radial direction of the reference headline plane by the radial distance corresponding to the radial clearance angle to obtain the point on the target headline.

[0102] For example, the axial offset point is

[0103]

[0104] The point on the target line is

[0105] Pn″=Pn′-Trn*Pn′Pn"

[0106] Optionally, a point on the reference guideline is offset radially along the reference guideline plane by a distance corresponding to the radial clearance angle to obtain a radial offset point; this radial offset point is then offset along the tool axis by a distance corresponding to the axial clearance angle to obtain a point on the target guideline. Specifically, the radial vector corresponding to the point on the reference guideline plane is obtained; the radial distance corresponding to the radial clearance angle is determined based on the reference radius, angle parameters, and the tangent of the radial clearance angle; the axial offset point is offset radially along the reference guideline plane by a distance corresponding to the radial clearance angle to obtain a radial offset point; the axial distance corresponding to the axial clearance angle is determined based on the product of the angle parameters, the tangent of the axial clearance angle, and the radius of the reference guideline plane; and the point on the target guideline is offset along the tool axis by an axial distance.

[0107] For example, the radial offset point is

[0108] Pn"=Pn-Trn*P n Pn"

[0109] The point on the target line is

[0110]

[0111] In this embodiment, the axial distance corresponding to the axial back angle of the point on the reference guideline is offset along the tool axis, and the radial distance corresponding to the radial back angle is offset along the plane of the reference guideline. The combination of the two includes the changes of the reference guideline in three-dimensional space, which can cover the back angle situation that occurs in the machining, simplify the trajectory calculation, and quickly realize the grinding control of the stepped surface.

[0112] In one embodiment, the grinding method for the stepped surface further includes: obtaining an initial grinding posture perpendicular to the stepped surface; rotating the initial grinding posture around the tool axis by an angle parameter to obtain the grinding posture.

[0113] Grinding of stepped surfaces on the workpiece based on grinding trajectories includes:

[0114] With this grinding posture, the workpiece is ground with a stepped surface based on the grinding trajectory.

[0115] Among them, grinding posture represents the direction of the central axis of the grinding tool.

[0116] Specifically, the initial grinding posture perpendicular to the stepped surface is determined based on the taper angle δ, such as the initial grinding posture Vg0 being...

[0117]

[0118] Then, by rotating the initial grinding posture Vg0 around the tool axis by the angle parameter θ, the grinding posture Vg of the grinding tool is obtained. n :

[0119]

[0120] The CNC machine, in this grinding posture, grinds the workpiece according to the grinding tool position indicated by the grinding trajectory to obtain the stepped surface.

[0121] In this embodiment, the initial grinding posture perpendicular to the stepped surface is obtained, and the initial grinding vector is rotated around the tool axis by an angle parameter to obtain the grinding posture. With this grinding posture, the stepped surface of the workpiece is ground based on the grinding trajectory, which enables the grinding tool to be tangent to the grinding surface better, thereby improving the grinding effect.

[0122] In one embodiment, the stepped surface is a ruled surface similar to a cone, which can be considered as a set of straight lines distributed along a fixed path point. In the tool structure, controlling its radial and axial clearance angles is of paramount importance. This embodiment describes the tool in the order of considering the axial clearance angle first, followed by the radial clearance angle.

[0123] A stepped surface can be visualized as a series of generatrices distributed at points on a certain curve (directrix). In this embodiment, a discrete method (i.e., a step size of θs) is used to solve for the point P on the directrix trajectory and its corresponding generatrices. The discrete variable is chosen as the rotation angle θ, which is the angle between the reference directrix trajectory point P in the XY plane and the X-axis. The discrete step size is θs, where θ = n * θs, and n represents the nth point.

[0124] I. Ignoring the axial clearance angle α1 and radial clearance angle α2, and considering only the taper angle δ, the stepped surface is an ideal frustum lateral surface. The starting point is on the X-axis, and the sweep trajectory is the reference directrix, i.e., the arc of the frustum end face. Therefore, the initial generatrix vector T0 is...

[0125]

[0126] Point Pn on the reference line corresponding to different angular parameters θ is

[0127]

[0128] Where R1 is the radius of the reference plane.

[0129] Based on the rotation matrix corresponding to the angle parameters, the initial generatrix vector T0 is rotated around the tool axis by the rotation angle θ of point Pn on the reference line, thus obtaining the target generatrix vector Tn corresponding to point Pn on the reference line:

[0130]

[0131] II. Stepped surfaces exhibit diverse forms, and in manufacturing processes, they are generally determined using the axial clearance angle and the radial clearance angle. First, consider the axial clearance angle α1, which can be interpreted as the angle between the tangent vector at point Pn on the reference directrix and the tangent vector at point Pn′ on the directrix after considering the axial clearance angle α1. For example... Figure 3 As shown, this can be considered a cylindrical helix. Point Pn moves along the arc while simultaneously moving downwards along the axial direction by Z as the angle parameter increases. n Then there is

[0132] Z n =R1*(θs*n)*tanα1

[0133] Offset point Pn on the reference guideline by the axial distance Z along the tool axis. nObtain point Pn′ on the target standard line:

[0134]

[0135] III. Consider the radial clearance angle α2. The radial clearance angle α2 is the angle between the tangent vector of point Pn on the reference line in the XY plane and the tangent vector of point Pn″ after considering the radial clearance angle α2, such as... Figure 4 As shown. In the XY plane, referring to the polar coordinate representation, point Pn is determined by the rotation angle θ and the radius. A discrete iterative method is used to facilitate the solution, from P... n-1 Moving to point Pn can be decomposed into rotation and rotation along the radial vector Tr. n These two movements are considered. Therefore, point Pn″ is obtained by moving point Pn a certain distance radially along the reference line (ideal circular arc) corresponding to the same rotation angle θ.

[0136] Obtain the radial vector Tr corresponding to point Pn on the reference directrix in the reference directrix plane. n :

[0137]

[0138] by Figure 4 For example, Figure 4 P as represented in n-1 It is a starting point, and at this point, the reference point is point P. n-1 Point P on the target line n-1 "For the same point, point P on the previous reference line can be..." n-1 As a point on the previous target line. Rp n-1 That is, P n-1 The radius corresponding to the point. Furthermore, it can be understood that if point Pn coincides with point Pn′ on the XY plane, then Rp... n Let Pn' and Pn' be the radii corresponding to points Pn and Pn' respectively. Pn'Pn'" is the distance between the nth point Pn' (considering the axial rearward angle α1) and the nth point Pn'' (considering the radial rearward angle α2) in the XY plane. Since the discrete angular step size θs is very small, the angles Pn''Pn''Pn''Pn''... n-1 It can be approximated as a right angle, so:

[0139] Rp n =Rp n-1 -Pn′Pn″

[0140] Pn′Pn″=(Rp n-1 -Rp n-1 *θs*tanα2)

[0141] Taking all factors into consideration, the final expression for point Pn″ on the target standard line is:

[0142] Pn″=Pn′-Trn*Pn′Pn″

[0143] Given that the initial n is 1, and the radius Rp0 corresponding to the initial point P0 is R1, substituting these values ​​allows for iterative solutions to obtain the discrete point set Pn″ and its corresponding values. For example, the current Rp... n Rp as the next calculation n-1 Then you can obtain the next Pn″.

[0144] IV. Grinding trajectory and grinding posture of the grinding wheel

[0145] Given each discrete point P on the target standard line and the corresponding generatrix vector direction, the grinding wheel cutter position (center point) and the cutter axis vector can be determined.

[0146] The grinding trajectory Gpn of the grinding wheel is

[0147] Gpn=Pn″+Tn*Gr

[0148] Where Gr is the radius of the grinding wheel.

[0149] The grinding wheel is used for face grinding. The generatrix corresponding to each point Pn should be on the end face of the grinding wheel. At the same time, in order to reduce interference, the axis of the grinding wheel should be perpendicular to the initial frustum surface. Therefore:

[0150]

[0151] This means that the initial grinding posture Vg0 is rotated around the tool axis by an angle parameter θ to obtain the grinding posture Vg of the grinding tool. n .

[0152] Finally, the grinding trajectory and grinding posture of the grinding wheel are obtained. After post-processing to obtain the corresponding CNC program code, the stepped surface can be obtained by grinding on a CNC machine.

[0153] In this embodiment, by determining the structural parameters of the stepped surface, and then calculating based on these parameters to obtain diverse frustum surfaces, the cutting performance of the tool can be adjusted. This invention employs a discrete iterative numerical calculation method, starting from an ideal conical surface. Utilizing the idea that multiple generatrices of a ruled surface are distributed on the guideline points, it satisfies the control of axial and radial clearance angles in the process, simplifies trajectory calculation, is easy to understand, and effectively achieves stepped surface grinding control.

[0154] In one embodiment, a method for grinding a stepped surface of a cutting tool includes:

[0155] Step (a1) involves rotating the initial generatrix vector representing the taper angle on the stepped surface around the tool axis by an angle parameter to obtain the target generatrix vector corresponding to the point on the reference guideline.

[0156] Step (a2) determines the axial distance corresponding to the axial rear angle based on the product of the angle parameter, the tangent of the axial rear angle, and the radius of the reference plane.

[0157] Step (a3) ​​is to obtain the radial vector corresponding to the point on the reference line in the reference line plane.

[0158] Step (a4) is to obtain the radius of the point on the current target line based on the product of the radius, angular step distance and tangent of the radial back angle of the point on the previous target line.

[0159] Step (a5) determines the difference between the radius of the point on the previous target line and the radius of the point on the current target line, and obtains the radial distance corresponding to the radial rear angle.

[0160] Step (a6) involves offsetting the point on the reference guideline by the axial distance corresponding to the axial back angle along the tool axis, and by the radial distance corresponding to the radial back angle along the plane of the reference guideline, to obtain the point on the target guideline.

[0161] Step (a7): Based on the points on the target standard line, determine the grinding points located on the corresponding target generatrix vector to obtain the grinding trajectory.

[0162] Step (a8) obtains the initial grinding posture perpendicular to the stepped surface.

[0163] Step (a9) involves rotating the initial grinding posture around the tool axis by an angle parameter to obtain the grinding posture.

[0164] Step (a10): Grind the stepped surface of the workpiece in a grinding posture based on the grinding trajectory.

[0165] In this embodiment, the stepped surface can be regarded as a series of generatrices distributed on the points of the guideline. Under the requirements of the tool grinding scenario, the direction of the generatrices does not change due to various offsets of the guideline. Therefore, for stepped surfaces under different conditions, the target generatrice vector corresponding to the point on the reference guideline of the same stepped surface can be obtained. The point on the reference guideline is offset along the preset direction by a distance corresponding to a preset back angle to obtain the point on the target guideline. Based on the point on the target guideline, the grinding point located on the corresponding target generatrice vector is determined to obtain the grinding trajectory. That is, it is derived from the ideal frustum surface. By using the idea of ​​multiple generatrices distributed on the guideline, the point on the reference guideline is offset by a distance corresponding to a preset back angle to meet the back angle control in the process. This simplifies the trajectory calculation and quickly realizes the grinding of the stepped surface.

[0166] It should be understood that, although the above Figure 2In the flowchart, the steps are shown sequentially according to the arrows, and the steps (a1) to (a10) 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 2 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.

[0167] In one embodiment, a stepped surface grinding apparatus for a cutting tool, which may employ software modules, hardware modules, or a combination of both as part of a computer device, specifically includes: a target generatrix vector acquisition module, an offset module, a grinding trajectory determination module, and a grinding module, wherein:

[0168] The target generatrix vector acquisition module is used to acquire the target generatrix vector corresponding to the point on the reference guideline of the stepped surface;

[0169] The offset module is used to offset a point on the reference line by a distance corresponding to a preset rear angle along a preset direction to obtain a point on the target line.

[0170] The grinding trajectory determination module is used to determine the grinding point located on the corresponding target generatrix vector based on the point on the target standard line, and obtain the grinding trajectory;

[0171] The grinding module is used to grind stepped surfaces on the workpiece based on the grinding trajectory.

[0172] In one embodiment, the target generatrix vector acquisition module is used to obtain the target generatrix vector corresponding to a point on the reference guideline by rotating the initial generatrix vector representing the taper angle on the stepped surface around the tool axis by an angle parameter.

[0173] In one embodiment, the preset direction includes the tool axis; the preset clearance angle includes an axial clearance angle, which represents the angle of change of a point on the reference line along the tool axis; the offset module is used for:

[0174] Based on the product of the angle parameter, the tangent of the axial clearance angle, and the radius of the reference plane, determine the axial distance corresponding to the axial clearance angle; offset the point on the reference line along the tool axis by the axial distance to obtain the point on the target line.

[0175] In one embodiment, the preset direction includes the radial direction of the reference guideline plane; the preset rear angle includes a radial rear angle, which represents the angle of change of a point on the reference guideline in the radial direction of the reference guideline plane; the offset module is used for:

[0176] Obtain the radial vector corresponding to a point on the reference directrix on the reference directrix plane;

[0177] Based on the reference radius, angle parameters, and the tangent of the radial rear angle, determine the radial distance corresponding to the radial rear angle;

[0178] The point on the reference line is offset radially by a radial distance along the radial vector to obtain the point on the target line.

[0179] In one embodiment, the reference radius is the radius of a point on the previous target line; the angle parameter includes the angular step distance between the two points; the offset module is used for:

[0180] The radius of the point on the current target line is obtained by multiplying the radius, angular step, and tangent of the radial rear angle of the point on the previous target line.

[0181] Determine the difference between the radius of a point on the previous target line and the radius of a point on the current target line, and obtain the radial distance corresponding to the radial rear angle.

[0182] In one embodiment, the preset direction includes the tool axis and the radial direction of the reference plane; the preset clearance angle includes an axial clearance angle and a radial clearance angle, wherein the axial clearance angle represents the angle of change of a point on the reference plane in the tool axis, and the radial clearance angle represents the angle of change of a point on the reference plane in the radial direction.

[0183] Offset module, used for:

[0184] The point on the reference guideline is obtained by offsetting the point along the tool axis by the axial distance corresponding to the axial back angle, and by offsetting the point along the reference guideline plane by the radial distance corresponding to the radial back angle.

[0185] In one embodiment, the stepped surface grinding apparatus for the tool further includes a grinding posture determination module, which is used for:

[0186] Obtain the initial grinding posture perpendicular to the stepped surface;

[0187] The initial grinding posture is rotated around the tool axis by an angle parameter to obtain the grinding posture;

[0188] The grinding module is used to grind stepped surfaces on the workpiece in a grinding posture based on the grinding trajectory.

[0189] Specific limitations regarding the stepped surface grinding apparatus for cutting tools can be found in the limitations of the stepped surface grinding method for cutting tools described above, and will not be repeated here. Each module in the aforementioned stepped surface grinding apparatus for cutting tools can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device in hardware form, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module.

[0190] In one embodiment, a computer device is provided, which may be a numerical control machine, and its internal structure diagram may be as shown below. Figure 5 As shown, the computer device includes a processor, memory, communication interface, display screen, and input devices connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media 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 media. The communication interface is used 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 stepped surface grinding method for a cutting tool. 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 mounted on the computer device casing, or an external keyboard, touchpad, or mouse.

[0191] Those skilled in the art will understand that Figure 5 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 computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0192] 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.

[0193] 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.

[0194] In one embodiment, a computer program product or computer program is provided, the computer program product or computer program including computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, causing the computer device to perform the steps in the above method embodiments.

[0195] 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.

[0196] 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 method for grinding stepped curved surfaces of a cutting tool, characterized in that, The method includes: Obtain the target generatrix vector corresponding to a point on the reference directrix of the stepped surface; the reference directrix is ​​the arc of the end face of the frustum; The point on the reference guideline is offset along a preset direction by a distance corresponding to a preset rear angle to obtain the point on the target guideline; Based on the points on the target standard line, determine the grinding points located on the corresponding target generatrix vector to obtain the grinding trajectory; The stepped surface of the workpiece is ground based on the grinding trajectory. The step of obtaining the target generatrix vector corresponding to a point on the reference directrix of the stepped surface includes: The initial generatrix vector representing the taper angle on the stepped surface is rotated around the tool axis by an angle parameter to obtain the target generatrix vector corresponding to the point on the reference line; The preset direction includes the radial direction of the reference guideline plane; the reference guideline plane is the end face of a stepped frustum; the preset rear angle includes a radial rear angle, which represents the angle of change of a point on the reference guideline in the radial direction of the reference guideline plane; The step of offsetting a point on the reference guideline by a distance corresponding to a preset rear angle along a preset direction to obtain a point on the target guideline includes: Obtain the radial vector corresponding to a point on the reference guideline in the reference guideline plane; Based on the reference radius, the angle parameter, and the tangent of the radial rear angle, the radial distance corresponding to the radial rear angle is determined; The point on the reference guideline is offset by the radial distance along the radial vector to obtain the point on the target guideline; The reference radius is the radius of a point on the previous target line; the angle parameter includes the angular step distance between two points; Determining the radial distance corresponding to the radial rear angle based on the reference radius, the angle parameter, and the tangent of the radial rear angle includes: The radius of the point on the current target line is obtained by multiplying the radius of the point on the previous target line, the angular step distance, and the tangent of the radial rear angle. The difference between the radius of a point on the previous target line and the radius of a point on the current target line is determined to obtain the radial distance corresponding to the radial rear angle.

2. The method according to claim 1, characterized in that, The preset direction also includes the tool axis; the preset clearance angle also includes an axial clearance angle, which represents the angle of change of a point on the reference line along the tool axis; The step of offsetting a point on the reference guideline by a distance corresponding to a preset rear angle along a preset direction to obtain a point on the target guideline further includes: The axial distance corresponding to the axial rear angle is determined based on the product of the angle parameter, the tangent of the axial rear angle, and the radius of the reference directrix plane. The point on the reference guideline is offset by the axial distance along the tool axis to obtain the point on the target guideline.

3. The method according to claim 1 or 2, characterized in that, The method further includes: Obtain the initial grinding posture perpendicular to the stepped surface; The initial grinding posture is rotated around the tool axis by the angle parameter to obtain the grinding posture; The grinding of the stepped surface of the workpiece based on the grinding trajectory includes: The stepped surface of the workpiece is ground in the aforementioned grinding posture based on the aforementioned grinding trajectory.

4. A stepped surface grinding device for cutting tools, characterized in that, The apparatus is used to implement the steps of the method according to any one of claims 1 to 3.

5. 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 according to any one of claims 1 to 3.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 3.

Images