Method, device and numerical control apparatus for grinding a threaded tool

Abstract

The application relates to a thread tool grinding method, device and numerical control equipment. The method comprises the following steps: determining the intersection between the chip flute edge line on the outer cylindrical surface of a blank and a thread guide line; determining the circumferential machining range of a machining track section from the intersection based on a machining range parameter; determining the axial distribution of the thread guide line along the tool axis within the circumferential machining range as the axial distribution of the machining track section along the tool axis from the intersection; decreasing the bottom surface circle radius of the blank along the circumferential deflection angle relative to the intersection based on a radial clearance angle parameter to obtain the radial distribution of the machining track section along the tool radial direction from the intersection; and determining the grinding track of a grinding wheel on the blank when grinding thread teeth based on the geometric parameters of the grinding wheel and the radial distribution and axial distribution of the machining track section. The method can ensure the grinding efficiency of the thread tool.

Description

Technical Field

[0001] This application relates to the field of machining technology, and in particular to a grinding method, apparatus and CNC equipment for thread cutting tools. Background Technology

[0002] With the development of machining technology, thread cutting tools have emerged. These tools use processes such as cutting and rolling to machine threaded structures on workpieces, enabling workpieces to be connected and fixed together via threads. The grinding quality of thread cutting tools directly determines the reliability of thread machining; therefore, the grinding of thread cutting tools is of paramount importance.

[0003] However, due to the complex thread structure on the thread cutting tool, it is difficult to plan the grinding trajectory of the thread cutting tool, and the problem of low grinding efficiency of the thread cutting tool cannot be avoided. Summary of the Invention

[0004] Therefore, it is necessary to provide a grinding method, apparatus, and CNC equipment for thread cutting tools that can improve grinding efficiency in response to the above-mentioned technical problems.

[0005] In a first aspect, this application provides a method for grinding thread cutting tools, comprising:

[0006] Determine the intersection point of the chip groove cutting line and the thread guide line on the outer cylindrical surface of the blank;

[0007] The circumferential processing range of the processing trajectory segment from the intersection point is determined based on the processing range parameters;

[0008] The axial distribution of the thread guide line along the tool axis within the circumferential machining range is defined as the axial distribution of the machining trajectory segment along the tool axis starting from the intersection point.

[0009] Based on the radial clearance angle parameter, the radius of the bottom circle of the blank is decreased with the circumferential deflection angle relative to the intersection point to obtain the radial distribution of the machining trajectory segment from the intersection point along the radial direction of the tool.

[0010] Based on the geometric parameters of the grinding wheel and the radial and axial distribution of the machining trajectory segment, the grinding trajectory of the grinding wheel when grinding thread teeth on the blank is determined.

[0011] Secondly, this application also provides a grinding apparatus for thread cutting tools, comprising:

[0012] The determination module is used to determine the intersection point between the chip groove cutting line and the thread guide line on the outer cylindrical surface of the blank; determine the circumferential machining range of the machining trajectory segment from the intersection point based on the machining range parameters; determine the axial distribution of the thread guide line along the tool axis within the circumferential machining range as the axial distribution of the machining trajectory segment from the intersection point along the tool axis; and obtain the radial distribution of the machining trajectory segment from the intersection point along the tool radial direction by decreasing the bottom circle radius of the blank with respect to the circumferential deflection angle relative to the intersection point based on the radial clearance angle parameters.

[0013] The planning module is used to determine the grinding trajectory of the grinding wheel when grinding thread teeth on the blank, based on the geometric parameters of the grinding wheel and the radial and axial distribution of the machining trajectory segment.

[0014] Thirdly, this application also provides a numerical control device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method.

[0015] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps in the above-described method.

[0016] Fifthly, this application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps in the above-described method.

[0017] The aforementioned thread-grinding methods, apparatuses, CNC equipment, storage media, and computer program products, in order to provide a geometric basis for the grinding trajectory planning of thread-grinding tools, require the distribution of thread teeth to be characterized by machining trajectory segments. To simplify the grinding trajectory planning process, without considering the partitioning of chip grooves and the offset of the tooth flank face relative to the outer cylindrical surface, the axial distribution of thread teeth is characterized by the thread guide line on the outer cylindrical surface of the blank. Since adjacent thread tooth segments in the circumferential direction are separated by chip grooves, the starting position of each thread tooth segment can be considered to be distributed on the cutting edge formed by the intersection of the chip groove and the thread tooth. The cutting edge formed by the intersection of the chip groove and the thread tooth is characterized by the chip groove cutting edge line on the outer cylindrical surface of the blank. By determining the intersection point between the chip groove cutting edge line and the thread guide line on the outer cylindrical surface of the blank, this intersection point can reflect the starting position of each thread tooth segment separated by the chip groove on the outer cylindrical surface.

[0018] Furthermore, based on the machining range parameters, the circumferential machining range of the machining trajectory segment from the intersection point is determined. The circumferential machining range reflects the distribution range of a thread tooth segment along the circumferential direction from the starting position. The axial distribution of the thread guide line along the tool axis within the circumferential machining range is determined as the axial distribution of the machining trajectory segment along the tool axis from the intersection point. The axial distribution of the machining trajectory segment reflects the axial distribution of a thread tooth segment along the tool axis from the starting position. Since the flank face of the thread tooth is offset inward relative to the outer cylindrical surface, in the radial plane perpendicular to the tool axis, the tangent of the flank face profile of the thread tooth at the intersection point has a radial clearance angle relative to the circumferential tangent at the intersection point. Based on the radial clearance angle parameter, the radius of the bottom circle of the blank is decreased with the circumferential deflection angle relative to the intersection point to obtain the radial distribution of the machining trajectory segment along the tool radial direction from the intersection point. The radial distribution of the machining trajectory segment reflects the radial distribution of a thread tooth segment along the tool radial direction from the starting position. The machining trajectory segment can completely and accurately reflect the distribution of a thread tooth, providing an accurate geometric basis for the grinding trajectory planning of the thread cutting tool. Therefore, based on the geometric parameters of the grinding wheel and the radial and axial distribution of the machining trajectory segment, the grinding trajectory of the grinding wheel when grinding thread teeth on the blank can be determined, which greatly simplifies the grinding trajectory planning process and can improve the grinding efficiency of the thread cutting tool. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic flowchart illustrating a thread-grinding method for an embodiment of this application.

[0021] Figure 2 This is a schematic diagram of a chip groove cutting edge and a thread guide provided in an embodiment of this application.

[0022] Figure 3 This is a schematic diagram of the intersection points provided in an embodiment of this application.

[0023] Figure 4 This is a schematic diagram of a three-dimensional model of two threading tools provided in the embodiments of this application.

[0024] Figure 5 This is a schematic diagram illustrating the radial distribution of a processing trajectory segment as provided in an embodiment of this application.

[0025] Figure 6The above and front views show a tool feed trajectory segment, a machining trajectory segment, a tool retraction trajectory segment, and a transition trajectory segment provided in the embodiments of this application.

[0026] Figure 7 This is a schematic diagram illustrating the grinding of a threaded tooth groove using a sharp-angled grinding wheel, as provided in an embodiment of this application.

[0027] Figure 8 This is a schematic diagram of the geometric parameters of a sharp-angled grinding wheel provided in an embodiment of this application.

[0028] Figure 9 This is a schematic diagram of grinding the back face of a threaded tooth with a flat grinding wheel, as provided in an embodiment of this application.

[0029] Figure 10 This is a schematic diagram showing the location of a grinding point according to an embodiment of this application.

[0030] Figure 11 This is a schematic diagram of a threading tool provided in an embodiment of this application.

[0031] Figure 12 This is a structural block diagram of a thread grinding device provided in an embodiment of this application.

[0032] Figure 13 This is an internal structural diagram of a CNC device provided in an embodiment of this application. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0034] In one exemplary embodiment, such as Figure 1 As shown, a schematic diagram of a grinding method for a thread cutting tool is provided. Taking the application of this method to a CNC machine as an example, the method includes the following steps 102 to 110.

[0035] Step 102: Determine the intersection point between the chip groove cutting line and the thread guide line on the outer cylindrical surface of the blank.

[0036] The blank includes a cylindrical blank used for grinding thread cutting tools. The outer cylindrical surface is the outer surface of the blank excluding the end faces. The chip flute cutting edge is used to characterize the cutting edge formed by the intersection of the thread teeth and the chip flutes. The thread guide line reflects the distribution of each segment of thread teeth along the tool axis. The tool axis refers to the direction of the tool axis located at the cylindrical center axis of the blank. The intersection point is the point where the chip flute cutting edge and the thread guide line intersect, reflecting the starting position of each segment of thread teeth.

[0037] In some embodiments, the CNC equipment can obtain the intersection point between the chip groove cutting line and the thread guide line on the outer cylindrical surface of the input blank.

[0038] In some embodiments, the CNC equipment can determine the intersection point between the chip groove cutting line and the thread guide line on the outer cylindrical surface of the blank based on the structural parameters of the blank, thread teeth, and chip groove.

[0039] In some embodiments, the CNC equipment can substitute the structural parameters of the blank, thread teeth, and chip groove into the mathematical expression of the intersection point in the reference coordinate system to obtain the position data of the intersection point in the reference coordinate system. The mathematical expression of the intersection point in the reference coordinate system is obtained by simultaneously solving the mathematical expressions of the chip groove cutting line and the thread guide line in the reference coordinate system.

[0040] In some embodiments, the structural parameters of the blank may include a tool diameter parameter. The tool diameter parameter characterizes the diameter of the bottom circle of the blank. The structural parameters of the thread teeth may include a pitch parameter. The pitch parameter characterizes the axial distance between two adjacent thread teeth along the tool axis. The pitch parameter indicates the distance traveled upwards along the tool axis after one revolution on the thread leader line. The structural parameters of the chip flute may include a helix angle parameter and a number of cutting edges parameter. The helix angle parameter characterizes the helix angle of the cutting edge formed by the intersection of the thread teeth and the chip flute. The helix angle parameter indicates the helix angle of the chip flute cutting edge line.

[0041] In some embodiments, the chip groove cutting edge can be a cylindrical helix. The thread guide line can also be a cylindrical helix. For example... Figure 2 The diagram illustrates a chip groove cutting edge line and a thread guide line. The dashed cylindrical helix is ​​the thread guide line constructed in a reference coordinate system, while the solid cylindrical helix is ​​the chip groove cutting edge line constructed in the reference coordinate system. The reference coordinate system... The first coordinate axis The third coordinate axis passes through the starting point of the first chip groove cutting edge line and the starting point of the thread guide line. Aligned with the tool axis.

[0042] In the reference coordinate system, the mathematical expression for the threaded guide is formula (1).

[0043] (1).

[0044] in, This represents the tool diameter parameter. The radius of the cylindrical base circle of the blank is also known as the tool radius. This represents the rotation angle corresponding to a point on the threaded guide line. The pitch parameter is represented by Formula (1). Formula (1) is used to describe the relationship between the position data of the points on the thread guide and the parameters in Formula (1).

[0045] In the reference coordinate system, the first The mathematical expression for the chip groove cutting edge is formula (2).

[0046] (2).

[0047] in, The radius of the cylindrical base circle representing the blank. This represents the rotation angle corresponding to a point on the chip groove cutting edge. Representing the The offset angle corresponding to each chip groove cutting edge line. The offset angle corresponding to each chip groove cutting edge line is used to characterize the offset angle of that chip groove cutting edge line relative to the first chip groove cutting edge line. This represents the number of blades. The helix angle parameter is represented by formula (2). Formula (2) is used to describe the relationship between the position data of the points on the chip groove cutting edge and the parameters in formula (2).

[0048] It is understandable that by combining formulas (1) and (2), we can obtain the mathematical expression for the intersection point.

[0049] In some embodiments, such as Figure 3 As shown, a schematic diagram of each intersection point is provided. Using the mathematical expression for the intersection points, we can obtain... Figure 3 The intersection points marked by the circles shown.

[0050] In some embodiments, the axial distribution of the machining trajectory segment may include the axial position at each rotation angle corresponding to different trajectory points. The rotation angle is the angle of rotation about the tool axis. The axial position may be the position component on the third coordinate axis in the reference coordinate system.

[0051] In some embodiments, the threading tool may include at least one of a tap or a thread milling cutter. Figure 4 The diagram shows three-dimensional model illustrations of two types of threading tools. If each segment of the threading tool has a descending helix, meaning there is a helical descending height between the start and end positions of a segment of the thread, then the thread guide line can be a helix. If each segment of the threading tool does not have a descending helix, meaning there is no helical descending height between the start and end positions of a segment of the thread, then the thread guide line can be multiple circumferences spaced apart along the tool's axial direction on the outer cylindrical surface.

[0052] Step 104: Determine the circumferential machining range of the machining trajectory segment from the intersection point based on the machining range parameters.

[0053] The machining range parameter reflects the angular range of each thread tooth segment in the circumferential direction around the tool axis. The machining trajectory segment characterizes the distribution of the thread teeth. The circumferential machining range reflects the angular range of the thread teeth whose starting position is at the intersection point in the circumferential direction.

[0054] For example, the circumferential machining range includes rotation angles corresponding to different trajectory points on the machining trajectory segment. The position data of the intersection point can include the rotation angle corresponding to the intersection point. It can be understood that the machining trajectory segment starts from the intersection point, so the starting point of the machining trajectory segment is the intersection point. The CNC equipment can determine the rotation angle corresponding to the intersection point as the rotation angle corresponding to the starting point of the machining trajectory segment. The circumferential deflection interval, which is not less than zero and not greater than the machining range parameter, is discretized to obtain each circumferential deflection angle. The circumferential deflection angle and the rotation angle corresponding to the starting point of the machining trajectory segment are superimposed to obtain each rotation angle within the circumferential machining range.

[0055] In some embodiments, the CNC equipment can superimpose the machining range parameters and the rotation angle corresponding to the starting point of the machining trajectory segment to obtain the rotation angle corresponding to the ending point of the machining trajectory segment. The interval formed by the rotation angles corresponding to the starting point and ending point of the machining trajectory segment is discretized to obtain each rotation angle within the circumferential machining range.

[0056] Step 106: Determine the axial distribution of the thread guide line along the tool axis within the circumferential machining range as the axial distribution of the machining trajectory segment from the intersection point along the tool axis.

[0057] The axial distribution of the machining trajectory segment is used to characterize the distribution of thread teeth along the tool axis at the intersection point where the starting position is located.

[0058] For example, the axial distribution of the machining trajectory segment can include the axial position of the machining trajectory segment at each rotation angle. The axial position is the distribution position along the tool axis. It can be understood that each rotation angle within the circumferential machining range is the rotation angle corresponding to each trajectory point on the machining trajectory segment. The CNC equipment can determine the axial position of the thread guide line at each rotation angle within the circumferential machining range as the axial position of the machining trajectory segment at that rotation angle.

[0059] In some embodiments, the CNC equipment can determine the axial position of the thread guide line at each rotation angle within the circumferential machining range as the axial position of the machining trajectory segment at that rotation angle by using the mathematical expression of the thread guide line in the reference coordinate system.

[0060] Step 108: Based on the radial back angle parameter, the radius of the bottom circle of the blank is reduced with the circumferential deflection angle of the relative intersection point to obtain the radial distribution of the machining trajectory segment from the intersection point along the radial direction of the tool.

[0061] The radial clearance angle parameter reflects the deflection angle of the tangent line to the two-dimensional profile of the thread tooth's relief face at the starting position, relative to the circumferential tangent line of the outer cylindrical surface at the starting position, within the radial plane. The radial plane is a plane perpendicular to the tool axis. The radial distribution of the machining trajectory segment characterizes the distribution of the thread teeth at the intersection point along the tool radial direction. The tool radial direction refers to the radial direction perpendicular to the tool axis. The tool radial direction of a point relative to the tool axis is the tool radial direction at that point. It can be understood that, within the radial plane, the deflection angle of the tangent line to the two-dimensional projection of the machining trajectory segment at the intersection point, relative to the circumferential tangent line of the outer cylindrical surface at the intersection point, should conform to the radial clearance angle parameter.

[0062] For example, the CNC equipment can decrease the radius of the bottom circle of the blank with the circumferential deflection angle of the relative intersection point, so that in the radial plane, the deflection angle of the tangent of the two-dimensional projection of the machining trajectory segment at the intersection point relative to the circumferential tangent of the outer cylindrical surface at the intersection point conforms to the radial clearance angle parameter, thereby obtaining the radial distribution of the machining trajectory segment along the radial direction of the tool from the intersection point. It should be noted that in this embodiment, the method of decreasing the radius of the bottom circle with the circumferential deflection angle of the relative intersection point is not specifically limited, as long as the structural requirements of the thread teeth are met and the radial distribution of the machining trajectory segment matches the radial clearance angle parameter.

[0063] In some embodiments, such as Figure 5 As shown, a schematic diagram of the radial distribution of the machining trajectory segments is provided. This represents the radial clearance angle parameter. Represents the tool radius. Represents the rotation angle. This represents the processing range parameter. Represents the rotation angle The radial distance from the radial position at the location to the tool axis. Rotation angle. The larger the value, the larger the circumferential deflection angle relative to the intersection point, and the larger the rotation angle. The radial distance at that point is smaller. This can be understood as the rotation angle... The radial distance at that point is obtained by decreasing the tool radius with respect to the circumferential deflection angle.

[0064] Step 110: Based on the geometric parameters of the grinding wheel and the radial and axial distribution of the machining trajectory segments, determine the grinding trajectory of the grinding wheel when grinding thread teeth on the blank.

[0065] For example, the radial distribution of the machining trajectory segments can include the radial positions of the machining trajectory segments at each rotation angle. The radial position is the distribution position along the radial direction of the tool. The axial distribution of the machining trajectory segments can include the axial positions of the machining trajectory segments at each rotation angle. The axial position is the distribution position along the axial direction of the tool. Each rotation angle corresponds to a different trajectory point. The radial and axial positions at the rotation angles corresponding to the trajectory points are the positional components of the trajectory points along the radial direction of the tool and along the axial direction of the tool.

[0066] CNC equipment can determine the grinding pose corresponding to a trajectory point on a machining trajectory segment based on the geometric parameters of the grinding wheel and the radial and axial positions of the machining trajectory segment at the corresponding rotation angle. The grinding pose characterizes the position of the grinding wheel when the radial direction of the grinding wheel at the grinding point on its outer edge is perpendicular to the tangent of the machining trajectory segment at that point. CNC equipment can determine the grinding trajectory of the grinding wheel when grinding thread teeth on a workpiece based on the grinding pose.

[0067] In some embodiments, the CNC equipment can determine the grinding trajectory based on a reference direction, the geometric parameters of the grinding wheel, and the radial and axial distribution of the machining trajectory segment. The grinding trajectory characterizes the path of the grinding wheel during the grinding of thread teeth on a workpiece, where the radial direction of the grinding wheel at the grinding point on the outer edge of the grinding wheel is perpendicular to both the reference direction and the tangent of the machining trajectory segment. It should be noted that the reference direction can be adaptively set, as long as grinding wheel interference is prevented.

[0068] In some embodiments, for a trajectory point on a machining trajectory segment, the grinding pose corresponding to the trajectory point is determined based on the reference direction, the geometric parameters of the grinding wheel, and the radial and axial positions of the machining trajectory segment at the corresponding rotation angle. The grinding pose is used to characterize the pose of the grinding wheel when the radial direction of the grinding wheel at the grinding point on the outer edge of the grinding wheel is perpendicular to both the reference direction and the tangent of the machining trajectory segment at the trajectory point.

[0069] In some embodiments, the grinding pose may include a grinding radial direction, a grinding axial direction, and a grinding position. The grinding radial direction characterizes the radial direction of the grinding wheel at the grinding point when grinding at the trajectory point. The grinding axial direction characterizes the axial direction of the grinding wheel when grinding at the trajectory point. The grinding position characterizes the position of the grinding wheel when grinding at the trajectory point. The CNC equipment can, for a trajectory point on a machining trajectory segment, perform a cross product between the vector of the reference direction and the vector of the tangent to the machining trajectory segment at the trajectory point to obtain the grinding radial direction corresponding to the trajectory point. Performing a cross product between the grinding radial direction and the vector of the tangent to the machining trajectory segment at the trajectory point yields the grinding axial direction corresponding to the trajectory point. The grinding position is determined based on the geometric parameters of the grinding wheel, the grinding radial direction, the grinding axial direction, and the radial and axial positions of the machining trajectory segment at the corresponding rotation angle.

[0070] In some embodiments, the reference direction may include the tool axis. The CNC equipment can use formula (3) to determine the grinding axis and grinding radial direction corresponding to the trajectory points on the machining trajectory segment.

[0071] (3).

[0072] in, A vector representing the reference direction. The vector representing the grinding radial direction. The vector representing the grinding axis. The vector represents the tangent line of the machining trajectory segment at the trajectory point. The symbol "T" in the upper right corner of the matrix is ​​an abbreviation for transpose, which means to interchange the rows and columns of the matrix. It can be understood that formula (3) is used to describe the relationship between the vector of the reference direction, the vector of the grinding radial direction, and the vector of the grinding axial direction.

[0073] In the aforementioned thread grinding method, to provide a geometric basis for the grinding trajectory planning of the thread tool, the distribution of thread teeth needs to be characterized by the machining trajectory segments. To simplify the grinding trajectory planning process, without considering the interruption of the chip grooves and the offset of the tooth flank face relative to the outer cylindrical surface, the axial distribution of thread teeth is characterized by the thread guide line on the outer cylindrical surface of the blank. Since adjacent thread teeth in the circumferential direction are separated by chip grooves, the starting position of each thread tooth segment can be considered to be distributed on the cutting edge formed by the intersection of the chip groove and the thread tooth. The cutting edge formed by the intersection of the chip groove and the thread tooth is characterized by the chip groove cutting edge line on the outer cylindrical surface of the blank. By determining the intersection point between the chip groove cutting edge line and the thread guide line on the outer cylindrical surface of the blank, this intersection point can reflect the starting position of each thread tooth segment separated by the chip groove on the outer cylindrical surface.

[0074] Furthermore, based on the machining range parameters, the circumferential machining range of the machining trajectory segment from the intersection point is determined. The circumferential machining range reflects the distribution range of a thread tooth segment along the circumferential direction from the starting position. The axial distribution of the thread guide line along the tool axis within the circumferential machining range is determined as the axial distribution of the machining trajectory segment along the tool axis from the intersection point. The axial distribution of the machining trajectory segment reflects the axial distribution of a thread tooth segment along the tool axis from the starting position. Since the flank face of the thread tooth is offset inward relative to the outer cylindrical surface, in the radial plane perpendicular to the tool axis, the tangent of the flank face profile of the thread tooth at the intersection point has a radial clearance angle relative to the circumferential tangent at the intersection point. Based on the radial clearance angle parameter, the radius of the bottom circle of the blank is decreased with the circumferential deflection angle relative to the intersection point to obtain the radial distribution of the machining trajectory segment along the tool radial direction from the intersection point. The radial distribution of the machining trajectory segment reflects the radial distribution of a thread tooth segment along the tool radial direction from the starting position. The machining trajectory segment can completely and accurately reflect the distribution of a thread tooth, providing an accurate geometric basis for the grinding trajectory planning of the thread cutting tool. Therefore, based on the geometric parameters of the grinding wheel and the radial and axial distribution of the machining trajectory segment, the grinding trajectory of the grinding wheel when grinding thread teeth on the blank can be determined, which greatly simplifies the grinding trajectory planning process and can improve the grinding efficiency of the thread cutting tool.

[0075] In some embodiments, determining the intersection point between the chip groove cutting edge line and the thread guide line on the outer cylindrical surface of the blank includes: determining the intersection point between the chip groove cutting edge line and the thread guide line on the outer cylindrical surface of the blank based on pitch parameters, tool diameter parameters, number of cutting edges parameters, and helix angle parameters; wherein, the pitch parameter is used to characterize the axial distance between two adjacent thread teeth along the tool axis; the tool diameter parameter is used to characterize the bottom circle diameter of the blank; the number of cutting edges parameter is used to characterize the number of chip grooves; and the helix angle parameter is used to characterize the helix angle of the cutting edge formed by the intersection of the thread teeth and the chip grooves.

[0076] In some embodiments, the CNC equipment can use the mathematical expression of the intersection point to determine the intersection point between the chip groove cutting line and the thread guide line on the outer cylindrical surface of the blank based on the pitch parameter, tool diameter parameter, number of cutting edges parameter and helix angle parameter.

[0077] In some embodiments, the CNC equipment can substitute the pitch parameter, tool diameter parameter, number of cutting edges parameter, and helix angle parameter into the mathematical expression of the intersection point in the reference coordinate system to obtain the position data of the intersection point in the reference coordinate system. The position data of the intersection point includes the rotation angle corresponding to the intersection point.

[0078] In some embodiments, a process is provided as shown below, in which the mathematical expressions of the threaded guide line and the chip groove cutting edge line are solved simultaneously to obtain the mathematical expression of the intersection point.

[0079] First, the intersection point satisfies the simultaneous conditions of formulas (1) and (2). Formula (4) can be obtained from the fact that the coordinates on the third coordinate axis of formulas (1) and (2) are equal.

[0080] (4).

[0081] Formula (4) can be transformed to obtain formula (5).

[0082] (5).

[0083] in, Represents the tool radius. This represents the rotation angle corresponding to a point on the threaded guide line. This represents the pitch parameter. This represents the rotation angle corresponding to a point on the chip groove cutting edge. This represents the helix angle parameter.

[0084] Furthermore, since there are multiple chip groove cutting lines, the intersection points should also satisfy formula (6).

[0085] (6).

[0086] in, This represents the rotation angle corresponding to a point on the threaded guide line. This represents the rotation angle corresponding to a point on the chip groove cutting edge. The number of revolutions is an integer. Representing the The offset angle corresponding to the chip groove cutting edge line. This represents the blade length parameter. This represents the pitch parameter. This is understandable. This means that the ratio of the cutting edge length parameter to the pitch parameter is rounded up, which ensures that the distance between the first and last intersection points along the tool axis reaches the distribution length represented by the cutting edge length parameter, thereby ensuring that the cutting edge length reaches the cutting edge length parameter.

[0087] Formula (7) can be obtained based on formula (6) and formula (5).

[0088] (7).

[0089] Based on formulas (6) and (7), the mathematical expression for the intersection point is formula (8).

[0090] (8).

[0091] in, This represents the rotation angle corresponding to the intersection point. This represents the pitch parameter. This represents the helix angle parameter. The number of revolutions is an integer. Representing the The offset angle corresponding to the chip groove cutting edge line. , This represents the number of blades. Represents the tool radius. , The parameter represents the tool diameter. Formula (8) is used to describe the relationship between the position data of the intersection point and the parameters in formula (8).

[0092] It should be noted that the denominator in formula (8) This is the feature discriminant. When When the system degrades, the CNC equipment can exit the logic of finding the intersection point using formula (8). Wherein, This represents a safety threshold. It's understandable that, to prevent system degradation caused by a denominator of zero, a minimum value is typically set as the safety threshold.

[0093] In some embodiments, the mathematical expression for the intersection point is not limited to formula (8). For example, the problem of the intersection of the thread guide line and the chip groove cutting edge line in space can be abstracted as a phase matching problem of two helical motions.

[0094] Specifically, characteristic coefficients can be defined as in formula (9).

[0095] (9).

[0096] in, Represents the characteristic coefficient. This represents the pitch parameter. This represents the helix angle parameter. Represents the tool radius. Formula (9) is used to describe the relationship between the characteristic coefficient and the parameters in formula (9).

[0097] Based on formula (9), formula (7) can be transformed into formula (10).

[0098] (10).

[0099] Accordingly, the mathematical expression for the intersection point can be converted into formula (11).

[0100] (11).

[0101] in, This represents the rotation angle corresponding to the intersection point. Represents the characteristic coefficient. The number of revolutions is an integer. Representing the The offset angle corresponding to the chip groove cutting edge line. This represents the number of blades. The diameter parameter represents the tool diameter. Formula (11) is used to describe the relationship between the position data of the intersection point and the parameters in formula (11).

[0102] It should be noted that when When the value approaches 1, the denominator of the mathematical expression for the intersection point in formula (11) approaches 0, corresponding to the special case where the two helical movements corresponding to the chip groove cutting edge line and the thread guide line are synchronized. Therefore, in order to ensure grinding efficiency, the CNC equipment can... A prompt will be given when the value approaches 1.

[0103] In some embodiments, the CNC equipment can determine the intersection point between the chip groove cutting line and the thread guide line on the outer cylindrical surface of the blank based on the cutting edge length parameter, pitch parameter, tool diameter parameter, number of cutting edges parameter, and helix angle parameter. The cutting edge length parameter is used to characterize the distribution length of the cutting edge along the tool axis and can indicate the distribution length of the chip groove cutting line along the tool axis.

[0104] In this embodiment, the intersection point between the chip groove cutting line and the thread guide line on the outer cylindrical surface of the blank is determined based on the pitch parameter, tool diameter parameter, number of cutting edges parameter and helix angle parameter. This realizes the mapping from the structural parameters of the thread cutting tool to the intersection point in geometric space, ensuring that the determined intersection point meets the structural requirements of the thread cutting tool and can guarantee the grinding effect of the thread cutting tool.

[0105] In some embodiments, the radius of the bottom circle of the blank is decreased with the circumferential deflection angle relative to the intersection point based on the radial clearance angle parameter to obtain the radial distribution of the machining trajectory segment from the intersection point along the radial direction of the tool. This includes: based on an exponential decay coefficient matched with the radial clearance angle parameter, the radius of the bottom circle of the blank is decreased exponentially with the circumferential deflection angle relative to the intersection point to obtain the radial distribution of the machining trajectory segment from the intersection point along the radial direction of the tool.

[0106] For example, the CNC equipment can determine the cotangent value of the complementary angle of the radial clearance angle parameter as an exponential decay coefficient. The CNC equipment can discretize the circumferential deflection interval, which is not less than zero and not greater than the machining range parameter, to obtain each circumferential deflection angle. Based on the exponential decay coefficient, the tool radius decays exponentially with the circumferential deflection angle to obtain the radial distance corresponding to the circumferential deflection angle. The radial distance corresponding to the circumferential deflection angle is used to characterize the distance from the trajectory point of the relative intersection point along the circumferential direction to the tool axis. The CNC equipment can superimpose the circumferential deflection angle and the rotation angle corresponding to the intersection point to obtain the rotation angle corresponding to the trajectory point within the circumferential machining range. The radial position of the machining trajectory segment at that rotation angle is determined based on the radial distance corresponding to the circumferential deflection angle and the rotation angle corresponding to the trajectory point.

[0107] In some embodiments, the CNC equipment can utilize the exponential decay formula to decrease the tool radius exponentially with the circumferential deflection angle according to the exponential decay coefficient, thereby obtaining the radial distance corresponding to the circumferential deflection angle. Specifically, the exponential decay formula can be formula (12).

[0108] (12).

[0109] in, This represents the radial distance corresponding to the circumferential deflection angle. Represents the tool radius. It represents the circumferential deflection angle. This represents the radial clearance angle parameter. This represents the processing range parameter. It is the Euler number. Formula (12) is used to describe the relationship between the radial distance corresponding to the circumferential deflection angle and the parameters in formula (12).

[0110] CNC equipment can use the mathematical expression of the machining trajectory segment to determine the radial position of the machining trajectory segment at the rotation angle based on the radial distance corresponding to the circumferential deflection angle and the rotation angle corresponding to the trajectory point. Specifically, the mathematical expression of the machining trajectory segment is formula (13).

[0111] (13).

[0112] in, The representative machining trajectory segment corresponds to the circumferential deflection angle. The location data of the trajectory points. Circumferential deflection angle The corresponding radial distance. This represents the rotation angle corresponding to the intersection point. This represents the pitch parameter. The parameters represent the processing range. Formula (13) is used to describe the relationship between the position data of the trajectory points on the processing trajectory segment and the parameters in formula (13).

[0113] In some embodiments, the CNC equipment can discretize the interval formed by the rotation angles corresponding to the start and end points of the machining trajectory segment to obtain the rotation angles corresponding to the trajectory points within the circumferential machining range. Based on an exponential decay coefficient, the tool radius is exponentially decayed by the difference in circumferential deflection angle between the rotation angle corresponding to the trajectory point and the rotation angle corresponding to the intersection point, yielding the radial distance from the trajectory point to the tool axis. The CNC equipment can determine the radial position of the machining trajectory segment at that rotation angle based on the radial distance from the trajectory point to the tool axis and the rotation angle corresponding to the trajectory point.

[0114] In some embodiments, the CNC equipment can use an exponential decay formula to exponentially decay the tool radius with respect to the difference between the circumferential deflection angle between the rotation angle corresponding to the trajectory point and the rotation angle corresponding to the intersection point, based on the exponential decay coefficient, to obtain the radial distance from the trajectory point to the tool axis.

[0115] Specifically, the exponential decay formula can be Equation (14).

[0116] (14).

[0117] in, The segment representing the machining trajectory corresponds to the rotation angle The radial distance from the trajectory point to the tool axis. Represents the tool radius. This represents the rotation angle corresponding to the intersection point. It represents the circumferential deflection angle. This represents the processing range parameter. Represents the radial clearance angle parameter. Formula (14) is used to describe the relationship between the radial distance from the trajectory point to the tool axis and the parameters in formula (14).

[0118] CNC equipment can use the mathematical expression of the machining trajectory segment to determine the radial position of the machining trajectory segment at the rotation angle based on the radial distance from the trajectory point corresponding to the rotation angle to the tool axis and the rotation angle corresponding to the trajectory point. The radial position includes the position components on the first coordinate axis and the position components on the second coordinate axis. Specifically, the mathematical expression of the machining trajectory segment can be formula (15).

[0119] (15).

[0120] in, The segment representing the machining trajectory corresponds to the rotation angle The location data of the trajectory points. The segment representing the machining trajectory corresponds to the rotation angle The radial distance from the trajectory point to the tool axis. This represents the rotation angle corresponding to the intersection point. This represents the processing range parameter. The pitch parameter is represented by Formula (15). Formula (15) is used to describe the relationship between the radial distance from the trajectory point to the tool axis and the parameters in Formula (15).

[0121] In this embodiment, based on the exponential decay coefficient matching the radial clearance angle parameter, the radius of the bottom circle of the blank is decreased exponentially with the circumferential deflection angle relative to the intersection point, so as to obtain the radial distribution of the machining trajectory segment from the intersection point along the radial direction of the tool. The machining trajectory segment can accurately characterize the distribution of the thread teeth along the radial direction of the tool, providing an accurate geometric basis for the grinding trajectory planning of the thread tool.

[0122] In some embodiments, the grinding trajectory of the grinding wheel when grinding thread teeth on a blank is determined based on the geometric parameters of the grinding wheel and the radial and axial distribution of the machining trajectory segments. This includes: determining an infeed trajectory segment whose endpoint is connected to the starting point of the machining trajectory segment and whose radial offset distance along the starting point of the machining trajectory segment matches the infeed distance parameter; determining a retraction trajectory segment whose starting point is connected to the ending point of the machining trajectory segment and whose radial offset distance along the ending point of the machining trajectory segment matches the retraction distance parameter; determining the grinding pose corresponding to the trajectory points on the machining trajectory segment according to the geometric parameters of the grinding wheel and the radial and axial distribution of the machining trajectory segments; and determining the grinding trajectory of the grinding wheel when grinding thread teeth on a blank according to the geometric parameters of the grinding wheel, the grinding pose corresponding to the trajectory points on the machining trajectory segment, the infeed trajectory segment, and the retraction trajectory segment.

[0123] For example, the CNC equipment can use the mathematical expression of the infeed trajectory segment to determine the position data of the trajectory points on the infeed trajectory segment based on the starting point of the machining trajectory segment, the tool radial distance at the starting point of the machining trajectory segment, and the infeed distance parameters. Specifically, the mathematical expression of the infeed trajectory segment can be formula (16).

[0124]

[0125] in, The weighted parameters correspond to the infeed trajectory segment. The location data of the trajectory points. For Discretized and used as weighting parameters Take the value, then substitute it into This will give you the corresponding weighting parameters. The position data of the trajectory points on the feed trajectory segment. This represents the starting point of the tool infeed trajectory segment. This represents the starting point of the processing trajectory segment. This represents the feed distance parameter. The radial direction of the tool at the starting point of the machining trajectory segment. The rotation angle corresponding to the starting point of the machining trajectory segment. The symbol "T" in the upper right corner of the matrix is ​​an abbreviation for transpose, which means to interchange the rows and columns of the matrix. It can be understood that the rotation angle corresponding to the starting point of the machining trajectory segment can also be regarded as the azimuth angle of the starting point of the machining trajectory segment. Formula (16) is used to describe the relationship between the position data of the trajectory points on the feed trajectory segment and the parameters in formula (16).

[0126] CNC equipment can use the mathematical expression of the retraction trajectory segment to determine the retraction trajectory segment based on the endpoint of the machining trajectory segment, the tool radial distance at the endpoint of the machining trajectory segment, and the retraction distance parameters. Specifically, the mathematical expression of the retraction trajectory segment can be formula (17).

[0127]

[0128] in, The weighted parameter corresponds to the retraction trajectory segment. The location data of the trajectory points. For Discretized and used as weighting parameters Take the value, then substitute it into This will give you the corresponding weighting parameters. The position data of the trajectory points on the retraction trajectory segment. This represents the end point of the retraction trajectory segment. This represents the end point of the processing trajectory segment. This represents the retraction distance parameter. The radial direction of the tool at the end of the machining trajectory segment. The rotation angle corresponding to the end point of the machining trajectory segment. The symbol "T" in the upper right corner of the matrix is ​​an abbreviation for transpose, which means to interchange the rows and columns of the matrix. It can be understood that the rotation angle corresponding to the end point of the machining trajectory segment can also be regarded as the azimuth angle of the end point of the machining trajectory segment. Formula (17) is used to describe the relationship between the position data of the trajectory points on the retraction trajectory segment and the parameters in formula (17).

[0129] CNC equipment can use the mathematical expression of the tangent of the machining trajectory segment to determine the vector of the tangent at the trajectory point based on the rotation angle corresponding to the trajectory point. It can be understood that the mathematical expression of the tangent of the machining trajectory segment is obtained by differentiating the mathematical expression of the machining trajectory segment. Specifically, the mathematical expression of the tangent of the machining trajectory segment can be given by formula (18).

[0130] (18).

[0131] in, The vector representing the tangent to the processing trajectory segment. The mathematical expression representing the processing trajectory segment (15). This represents the exponential decay formula (14). This represents the rotation angle corresponding to the trajectory point on the machining trajectory segment. This represents the pitch parameter. Represents the tool radius. Represents the radial back angle parameter. Formula (18) is used to describe the relationship between the vector of the tangent of the machining trajectory segment and the parameters in formula (18).

[0132] CNC equipment can determine the grinding posture corresponding to each trajectory point on the machining trajectory segment based on the grinding wheel's geometric parameters and the tangent of the machining trajectory segment at that point. It can also determine the grinding posture corresponding to the trajectory points on the infeed trajectory segment based on the grinding wheel's geometric parameters and the grinding posture corresponding to the start point of the machining trajectory segment. Finally, it can determine the grinding posture corresponding to the trajectory points on the retraction trajectory segment based on the grinding wheel's geometric parameters and the grinding posture corresponding to the end point of the machining trajectory segment.

[0133] In this embodiment, an infeed trajectory segment is determined where the endpoint is connected to the starting point of the machining trajectory segment, and the radial offset distance of the tool along the starting point of the machining trajectory segment matches the infeed distance parameter; a retraction trajectory segment is determined where the starting point is connected to the endpoint of the machining trajectory segment, and the radial offset distance of the tool along the endpoint of the machining trajectory segment matches the retraction distance parameter; based on the geometric parameters of the grinding wheel and the radial and axial distribution of the machining trajectory segment, the grinding posture corresponding to the trajectory point on the machining trajectory segment is determined; based on the geometric parameters of the grinding wheel, the grinding posture corresponding to the trajectory point on the machining trajectory segment, the infeed trajectory segment, and the retraction trajectory segment, the grinding trajectory of the grinding wheel grinding thread teeth on the blank is determined, realizing the grinding trajectory planning of the thread tool from infeed to machining to retraction, which can ensure the grinding efficiency of the thread tool.

[0134] In some embodiments, the intersection points are distributed sequentially along the thread guide line; the distribution order of the machining trajectory segments starting from the intersection points is consistent with the distribution order of the intersection points; the grinding trajectory of the grinding wheel grinding thread teeth on the blank is determined according to the geometric parameters of the grinding wheel, the grinding posture corresponding to the trajectory points on the machining trajectory segment, the infeed trajectory segment, and the retraction trajectory segment, including: interpolating according to the end point of the retraction trajectory segment connected to the machining trajectory segment and the starting point of the infeed trajectory segment connected to the next machining trajectory segment in the subsequent distribution order to obtain the transition trajectory segment; the grinding trajectory of the grinding wheel grinding thread teeth on the blank is determined according to the geometric parameters of the grinding wheel, the grinding posture corresponding to the trajectory points on the machining trajectory segment, the infeed trajectory segment, the retraction trajectory segment, and the transition trajectory segment.

[0135] For example, a CNC machine can perform curve interpolation in the radial plane and linear interpolation along the tool axis based on the endpoint of the retraction trajectory segment connected to the machining trajectory segment and the starting point of the infeed trajectory segment connected to the next machining trajectory segment in the subsequent distribution sequence, to obtain a transition trajectory segment. The curve interpolation method may include at least one of circular interpolation or Archimedean spiral interpolation.

[0136] CNC equipment can determine the grinding posture corresponding to the trajectory points on the feed trajectory segment based on the grinding wheel's geometric parameters and the grinding posture corresponding to the starting point of the machining trajectory segment. It can also determine the grinding posture corresponding to the trajectory points on the retraction trajectory segment based on the grinding wheel's geometric parameters and the grinding posture corresponding to the ending point of the machining trajectory segment. Finally, it can determine the grinding posture corresponding to the trajectory points on the transition trajectory segment based on the grinding wheel's geometric parameters, the grinding posture corresponding to the ending point of the retraction trajectory segment connected to the transition trajectory segment, and the grinding posture corresponding to the starting point of the feed trajectory segment connected to the transition trajectory segment.

[0137] In some embodiments, the CNC equipment can utilize the mathematical expression of the transition trajectory segment to perform Archimedean spiral interpolation in the radial plane and linear interpolation along the tool axis, based on the endpoint of the retraction trajectory segment connected to the machining trajectory segment and the starting point of the infeed trajectory segment connected to the next machining trajectory segment in the subsequent distribution sequence, to obtain the position data of the trajectory points on the transition trajectory segment. Specifically, the mathematical expression of the transition trajectory segment can be formula (19).

[0138] (19).

[0139] in, The first segment representing the transition trajectory. Location data of each trajectory point. Representing the The radial distance from each trajectory point to the tool axis. Representing the The rotation angle corresponding to each trajectory point. Representing the The axial position of each trajectory point. The endpoint of the retraction trajectory segment that connects to the machining trajectory segment. The radial vector of the tool at the location . represent The radial distance to the tool axis. Represents the starting point of the feed path segment connected to the next machining path segment. The radial vector of the tool at the location . represent The radial distance to the tool axis. This represents the number of interpolation points. Formula (19) is used to describe the relationship between the position data of the trajectory points on the transition trajectory segment and the parameters in formula (19).

[0140] In this embodiment, interpolation is performed based on the endpoint of the retraction trajectory segment connected to the machining trajectory segment and the starting point of the infeed trajectory segment connected to the next machining trajectory segment in the distribution order to obtain the transition trajectory segment. Based on the geometric parameters of the grinding wheel, the grinding pose corresponding to the trajectory points on the machining trajectory segment, the infeed trajectory segment, the retraction trajectory segment, and the transition trajectory segment, the grinding trajectory of the grinding wheel when grinding thread teeth on the blank is determined. This realizes the grinding trajectory planning from infeeding to machining a section of thread teeth, then retraction, and after transition, infeeding again to machine the next section of thread teeth, thereby achieving continuous grinding of each section of thread teeth and ensuring the grinding efficiency of the thread cutting tool.

[0141] In some embodiments, the CNC equipment can determine the grinding posture corresponding to the trajectory point on the infeed trajectory segment based on the grinding wheel's geometric parameters and the grinding posture corresponding to the starting point of the machining trajectory segment connected to the infeed trajectory segment. It can also determine the grinding posture corresponding to the trajectory point on the retraction trajectory segment based on the grinding wheel's geometric parameters and the grinding posture corresponding to the ending point of the machining trajectory segment connected to the retraction trajectory segment. Finally, it can determine the grinding posture corresponding to the trajectory point on the transition trajectory segment based on the grinding wheel's geometric parameters, the grinding posture corresponding to the ending point of the retraction trajectory segment connected to the transition trajectory segment, and the grinding posture corresponding to the starting point of the infeed trajectory segment connected to the transition trajectory segment.

[0142] In some embodiments, determining the grinding pose corresponding to the trajectory point on the machining trajectory segment based on the geometric parameters of the grinding wheel and the radial and axial distribution of the machining trajectory segment includes: for each trajectory point on the machining trajectory segment, determining the grinding pose corresponding to the trajectory point based on the geometric parameters of the grinding wheel and the tangent of the machining trajectory segment at the trajectory point; the grinding pose includes the grinding posture characterizing the attitude of the grinding wheel and the grinding position characterizing the position of the grinding wheel; determining the grinding trajectory when the grinding wheel grinds thread teeth on the blank based on the geometric parameters of the grinding wheel, the grinding pose corresponding to the trajectory point on the machining trajectory segment, the infeed trajectory segment, the retraction trajectory segment, and the transition trajectory segment includes: determining the grinding trajectory corresponding to the starting point of the machining trajectory segment connected to the infeed trajectory segment. The grinding posture is determined as the grinding posture corresponding to the trajectory point on the infeed trajectory segment; the grinding posture corresponding to the end point of the machining trajectory segment connected to the retraction trajectory segment is determined as the grinding posture corresponding to the trajectory point on the retraction trajectory segment; interpolation is performed on the grinding posture corresponding to the end point of the retraction trajectory segment connected to the transition trajectory segment and the grinding posture corresponding to the start point of the infeed trajectory segment connected to the transition trajectory segment to obtain the grinding posture corresponding to the trajectory point on the transition trajectory segment; for the trajectory points on the infeed trajectory segment, retraction trajectory segment and transition trajectory segment, the grinding pose corresponding to the trajectory point is determined according to the geometric parameters of the grinding wheel and the grinding posture corresponding to the trajectory point; the grinding trajectory of the grinding wheel grinding the thread teeth on the blank is determined based on the grinding pose.

[0143] For example, such as Figure 6 As shown, a top view and a front view are provided for the tool approach trajectory segment, machining trajectory segment, tool retraction trajectory segment, and transition trajectory segment. The top view shows the two-dimensional projection of each trajectory segment in the radial plane, and the positions of the dotted points are the positions of the intersection points.

[0144] CNC equipment can determine the vector of the tangent at a given trajectory point on a machining trajectory segment using the mathematical expression of the tangent to that point and the rotation angle corresponding to that point. The cross product of the tool axis vector and the vector of the tangent at that point yields the grinding radial direction. The cross product of the grinding radial direction and the vector of the tangent at that point yields the grinding axis.

[0145] CNC equipment can determine the grinding position based on the mathematical expression of the grinding position corresponding to the machining trajectory segment, according to the geometric parameters of the grinding wheel, the grinding radial direction, the grinding axial direction, and the radial and axial positions of the machining trajectory segment at the corresponding rotation angle. Specifically, the grinding position is the position of the grinding wheel center during grinding. The mathematical expression of the grinding position corresponding to the machining trajectory segment can be given by formula (20).

[0146] (20).

[0147] in, Represents the rotation angle The grinding position corresponding to the trajectory point. Represents the rotation angle The position data of the trajectory points. The position data of the trajectory points may include the radial position on the first and second coordinate axes, and the axial position on the third coordinate axis. Represents the rotation angle The grinding radial direction corresponding to the trajectory point. This represents the radius of the grinding wheel. This represents the depth of cut. Represents the rotation angle The grinding axis corresponding to the trajectory point. The thickness of the grinding wheel is represented by the formula (20). Formula (20) is used to describe the relationship between the grinding position corresponding to the trajectory point on the machining trajectory segment and the parameters in formula (20).

[0148] The CNC equipment can determine the grinding posture corresponding to the starting point of the machining trajectory segment connected to the infeed trajectory segment as the grinding posture corresponding to the trajectory point on the infeed trajectory segment. For the trajectory point on the infeed trajectory segment, the grinding position corresponding to the trajectory point on the infeed trajectory segment is determined by using the mathematical expression of the grinding position corresponding to the infeed trajectory segment, based on the position data of the trajectory point, the geometric parameters of the grinding wheel, and the grinding posture corresponding to the trajectory point. Specifically, the mathematical expression of the grinding position corresponding to the infeed trajectory segment can be formula (21).

[0149] (twenty one).

[0150] in, The weighted parameters correspond to the infeed trajectory segment. The grinding position corresponding to the trajectory point. This represents the weighted parameters. The position data of the trajectory points on the feed trajectory segment. This represents the grinding radial direction corresponding to the trajectory point on the feed path segment. This represents the radius of the grinding wheel. This represents the depth of cut. This represents the grinding axis corresponding to the trajectory point on the feed path segment. The thickness of the grinding wheel is represented by the formula (21). Formula (21) is used to describe the relationship between the grinding position corresponding to the trajectory point on the feed trajectory segment and the parameters in formula (21).

[0151] The CNC equipment can determine the grinding posture corresponding to the end point of the machining trajectory segment connected to the retraction trajectory segment as the grinding posture corresponding to the trajectory point on the retraction trajectory segment. For the trajectory point on the retraction trajectory segment, the grinding position corresponding to the trajectory point on the retraction trajectory segment is determined by using the mathematical expression of the grinding position corresponding to the retraction trajectory segment, based on the position data of the trajectory point, the geometric parameters of the grinding wheel, and the grinding posture corresponding to the trajectory point. Specifically, the mathematical expression of the grinding position corresponding to the retraction trajectory segment can be formula (22).

[0152] (twenty two).

[0153] in, The weighted parameter corresponds to the retraction trajectory segment. The grinding position corresponding to the trajectory point. This represents the weighted parameters. The position data of the trajectory points on the retraction trajectory segment. This represents the grinding radial direction corresponding to the trajectory point on the retraction trajectory segment. This represents the radius of the grinding wheel. This represents the depth of cut. This represents the grinding axis corresponding to the trajectory point on the retraction trajectory segment. The thickness of the grinding wheel is represented by the formula (22). Formula (22) is used to describe the relationship between the grinding position corresponding to the trajectory point on the retraction trajectory segment and the parameters in formula (22).

[0154] The CNC equipment can determine the grinding posture corresponding to the end point of the retraction trajectory segment connected to the transition trajectory segment as the grinding posture corresponding to the start point of the transition trajectory segment. It can also determine the grinding posture corresponding to the start point of the infeed trajectory segment connected to the transition trajectory segment as the grinding posture corresponding to the end point of the transition trajectory segment. Using the mathematical expression of the grinding posture corresponding to the transition trajectory segment, interpolation is performed based on the grinding postures corresponding to the start and end points of the transition trajectory segment to determine the grinding posture corresponding to the trajectory points on the transition trajectory segment. Specifically, the mathematical expression of the grinding posture corresponding to the transition trajectory segment can be (23).

[0155] (twenty three).

[0156] in, The first segment representing the transition trajectory. The grinding posture corresponding to each trajectory point. This represents the number of interpolation points. The grinding posture corresponding to the starting point of the transition trajectory segment. The grinding posture corresponds to the end point of the transition trajectory segment. The grinding posture includes the grinding radial direction and the grinding axial direction. Formula (23) is used to describe the relationship between the grinding radial and grinding axial vectors corresponding to the trajectory points on the transition trajectory segment and the parameters in formula (23).

[0157] The CNC equipment can determine the grinding position corresponding to the trajectory point on the transition trajectory segment by using the mathematical expression of the grinding position corresponding to the transition trajectory segment, based on the position data of the trajectory point, the geometric parameters of the grinding wheel, and the grinding posture corresponding to the trajectory point. Specifically, the mathematical expression of the grinding position corresponding to the retraction trajectory segment can be formula (24).

[0158] (twenty four).

[0159] in, The first segment representing the transition trajectory. The grinding position corresponding to each trajectory point. The first segment representing the transition trajectory. Location data of each trajectory point. This represents the grinding radial direction corresponding to the trajectory point on the transition trajectory segment. This represents the radius of the grinding wheel. This represents the depth of cut. The first segment representing the transition trajectory. The grinding axis corresponding to each trajectory point. The thickness of the grinding wheel is represented by the formula (24). Formula (24) is used to describe the relationship between the grinding position corresponding to the trajectory point on the transition trajectory segment and the parameters in formula (24).

[0160] In this embodiment, for each trajectory point on the machining trajectory segment, the grinding pose corresponding to the trajectory point is determined based on the geometric parameters of the grinding wheel and the tangent of the machining trajectory segment at the trajectory point. The grinding pose includes the grinding pose characterizing the attitude of the grinding wheel and the grinding position characterizing the position of the grinding wheel. The grinding pose corresponding to the starting point of the machining trajectory segment connected to the infeed trajectory segment is determined as the grinding pose corresponding to the trajectory point on the infeed trajectory segment. The grinding pose corresponding to the ending point of the machining trajectory segment connected to the retraction trajectory segment is determined as the grinding pose corresponding to the trajectory point on the retraction trajectory segment. Based on the grinding pose corresponding to the ending point of the retraction trajectory segment connected to the transition trajectory segment and the grinding pose corresponding to the starting point of the infeed trajectory segment connected to the transition trajectory segment... Interpolation is performed on the state to obtain the grinding posture corresponding to the trajectory point on the transition trajectory segment. For the trajectory points on the infeed trajectory segment, retraction trajectory segment, and transition trajectory segment, the grinding pose corresponding to the trajectory point is determined according to the geometric parameters of the grinding wheel and the grinding posture corresponding to the trajectory point. Based on the grinding pose, the grinding trajectory of the grinding wheel grinding the thread teeth on the blank is determined. The grinding trajectory planning is from infeed to machining a section of thread teeth and then to retraction, and after transition, to infeed again to machine the next section of thread teeth. The grinding poses corresponding to the trajectory points on the retraction trajectory segment, infeed trajectory segment, and transition trajectory segment are all directly or indirectly related to the grinding poses corresponding to the trajectory points on the machining trajectory segment, which can ensure the continuous grinding of each section of thread teeth, thereby ensuring grinding efficiency.

[0161] In some embodiments, the grinding wheel includes a pointed grinding wheel; determining the grinding trajectory of the grinding wheel when grinding thread teeth on a blank based on the geometric parameters of the grinding wheel and the radial and axial distribution of the machining trajectory segment includes: determining the grinding pose corresponding to the trajectory point on the machining trajectory segment according to the geometric parameters of the pointed grinding wheel, the depth of cut parameter, and the radial and axial distribution of the machining trajectory segment; the grinding pose is used to characterize the pose of the pointed grinding wheel when the distance between the grinding point on the outer edge of the pointed grinding wheel and the trajectory point matches the depth of cut parameter, and the radial direction of the grinding wheel at the grinding point is perpendicular to the tangent of the machining trajectory segment at the trajectory point; and determining the grinding trajectory of the pointed grinding wheel when grinding the tooth groove of the thread teeth on the blank based on the grinding pose.

[0162] For example, such as Figure 7 The diagram illustrates the grinding of a threaded tooth groove using a sharp-angled grinding wheel. The grinding pose characterizes the position of the sharp-angled grinding wheel when the distance between the grinding point on the outer edge of the grinding wheel and the trajectory point matches the depth of cut parameter, and the radial direction of the grinding wheel at the grinding point is perpendicular to the tool axis and the tangent of the machining trajectory segment at the trajectory point. The grinding pose can include the grinding axis, grinding radial direction, and grinding position. Figure 8 The diagram shows a schematic of the geometric parameters of a sharp-angled grinding wheel. This represents the thickness of the grinding wheel. This represents the radius of the grinding wheel. This represents the sharp angle of the grinding wheel. When a sharp-angled grinding wheel grinds the tooth groove of a thread, the distance between the grinding point on the outer edge and the trajectory point is non-zero.

[0163] The CNC equipment can determine the vector of the tangent of the machining trajectory segment at the trajectory point using formula (18) based on the rotation angle corresponding to the trajectory point. The cross product of the tool axial vector and the vector of the tangent of the machining trajectory segment at the trajectory point is used to obtain the grinding radial direction corresponding to the trajectory point. The cross product of the grinding radial direction and the vector of the tangent of the machining trajectory segment at the trajectory point is used to obtain the grinding axial direction corresponding to the trajectory point. Using formula (20), the grinding position is determined based on the geometric parameters of the angled grinding wheel, the grinding radial direction, the grinding axial direction, and the radial and axial positions of the machining trajectory segment at the corresponding rotation angle. The grinding trajectory of the angled grinding wheel when grinding the tooth groove of the thread teeth on the blank is determined according to the distribution order of the trajectory points on the trajectory segment and the corresponding grinding posture.

[0164] In this embodiment, the grinding pose corresponding to the trajectory point on the machining trajectory segment is determined based on the geometric parameters, depth of cut parameters, and radial and axial distribution of the machining trajectory segment of the sharp-angled grinding wheel. The grinding trajectory of the sharp-angled grinding wheel when grinding the tooth groove of the thread tooth on the blank is determined based on the grinding pose, thereby realizing the grinding of the tooth groove of the thread tooth and ensuring the grinding efficiency of the thread cutting tool.

[0165] In some embodiments, the grinding wheel includes a flat grinding wheel; determining the grinding trajectory of the grinding wheel when grinding thread teeth on a blank based on the geometric parameters of the grinding wheel and the radial and axial distribution of the machining trajectory segment includes: determining the grinding pose corresponding to the trajectory point on the machining trajectory segment according to the geometric parameters of the flat grinding wheel and the radial and axial distribution of the machining trajectory segment; the grinding pose is used to characterize the pose of the flat grinding wheel when the grinding point on the outer edge of the flat grinding wheel is in contact with the trajectory point and the radial direction of the grinding wheel at the grinding point is perpendicular to the tangent of the machining trajectory segment at the trajectory point; and determining the grinding trajectory of the flat grinding wheel when grinding the tooth flank face of the thread teeth on the blank according to the grinding pose.

[0166] For example, such as Figure 9 The diagram illustrates a flat grinding wheel grinding the flank face of a threaded tooth. The grinding pose characterizes the position of the flat grinding wheel when the grinding point on its outer edge contacts the trajectory point, and the radial direction of the grinding wheel at the grinding point is perpendicular to the tool axis and the tangent of the machining trajectory segment is at the trajectory point. Figure 10 As shown, a schematic diagram of the location of the grinding point is provided. This represents the grinding radial direction during flat grinding wheel grinding. This represents the direction of the tangent to the machining trajectory segment. When a flat grinding wheel grinds the tooth groove of a thread, the grinding point on the outer edge contacts the trajectory point.

[0167] The CNC equipment can determine the vector of the tangent of the machining trajectory segment at the trajectory point using formula (18) based on the rotation angle corresponding to the trajectory point. The cross product of the tool axial vector and the vector of the tangent of the machining trajectory segment at the trajectory point is used to obtain the grinding radial direction corresponding to the trajectory point. The cross product of the grinding radial direction and the vector of the tangent of the machining trajectory segment at the trajectory point is used to obtain the grinding axial direction corresponding to the trajectory point. Using formula (20), the grinding position is determined based on the geometric parameters of the flat grinding wheel, the grinding radial direction, the grinding axial direction, and the radial and axial positions of the machining trajectory segment at the corresponding rotation angle. The grinding trajectory of the flat grinding wheel grinding the tooth flank face of the thread teeth on the blank is determined according to the distribution order of the trajectory points on the trajectory segment and the corresponding grinding posture.

[0168] In this embodiment, the grinding posture corresponding to the trajectory point on the machining trajectory segment is determined according to the geometric parameters of the flat grinding wheel and the radial and axial distribution of the machining trajectory segment. The grinding trajectory of the flat grinding wheel when grinding the tooth flank face of the thread tooth on the blank is determined according to the grinding posture, thereby realizing the grinding of the tooth flank face of the thread tooth and ensuring the grinding efficiency of the thread tool.

[0169] In some embodiments, the CNC equipment can use formula (8) or formula (9) to determine the position data of the intersection point between the chip groove cutting line and the thread guide line on the outer cylindrical surface of the blank, based on the pitch parameter, tool diameter parameter, number of cutting edges parameter and helix angle parameter. The circumferential machining range includes each rotation angle corresponding to different trajectory points on the machining trajectory segment. The position data of the intersection point can include the rotation angle corresponding to the intersection point. The CNC equipment can determine the rotation angle corresponding to the intersection point as the rotation angle corresponding to the starting point of the machining trajectory segment. Discretize the circumferential deflection interval that is not less than zero and not greater than the machining range parameter to obtain each circumferential deflection angle. Superimpose the circumferential deflection angle and the rotation angle corresponding to the starting point of the machining trajectory segment to obtain each rotation angle within the circumferential machining range. Using formula (12), according to the exponential decay coefficient matched with the radial clearance angle parameter, the tool radius is decreased exponentially with the circumferential deflection angle to obtain the radial distance corresponding to the circumferential deflection angle. For each rotation angle within the circumferential machining range, the axial position of the thread guide line at that rotation angle is determined using formula (13), which is then used as the axial position of the machining trajectory segment at that rotation angle. The radial position of the machining trajectory segment at that rotation angle is determined based on the radial distance corresponding to the circumferential deflection angle and the rotation angle corresponding to the trajectory point. The position data of the trajectory point includes both radial and axial positions.

[0170] The CNC equipment can use formula (16) to determine the position data of the trajectory points on the feed trajectory segment connected to the machining trajectory segment based on the position data of the starting point of the machining trajectory segment and the tool radial and feed distance parameters at the starting point of the machining trajectory segment. Using formula (17), the position data of the trajectory points on the retraction trajectory segment can be determined based on the position data of the ending point of the machining trajectory segment and the tool radial and retraction distance parameters at the ending point of the machining trajectory segment. Using formula (19), the position data of the center of the interpolation arc can be determined based on the radius parameter of the interpolation arc, the position data of the ending point of the retraction trajectory segment connected to the machining trajectory segment, and the position data of the starting point of the feed trajectory segment connected to the next machining trajectory segment in the subsequent distribution order. Using formula (20), the position data of the trajectory points on the transition trajectory segment can be determined based on the position data of the center of the interpolation arc, the radius parameter, the position data of the ending point of the retraction trajectory segment connected to the machining trajectory segment, and the position data of the starting point of the feed trajectory segment connected to the next machining trajectory segment in the subsequent distribution order.

[0171] The CNC equipment can determine the vector of the tangent of the machining trajectory segment at the trajectory point using formula (18) based on the rotation angle corresponding to the trajectory point. The cross product of the tool axial vector and the vector of the tangent of the machining trajectory segment at the trajectory point is used to obtain the grinding radial direction corresponding to the trajectory point. The cross product of the grinding radial direction and the vector of the tangent of the machining trajectory segment at the trajectory point is used to obtain the grinding axial direction corresponding to the trajectory point. Using formula (20), the grinding position is determined based on the geometric parameters of the grinding wheel, the grinding radial direction, the grinding axial direction, and the radial and axial positions of the machining trajectory segment at the corresponding rotation angle.

[0172] To ensure the continuity of the grinding trajectory, the grinding posture corresponding to the trajectory point on the feed trajectory segment is consistent with the grinding posture corresponding to the starting point of the machining trajectory segment connected to the feed trajectory segment. The CNC equipment can determine the grinding posture corresponding to the starting point of the machining trajectory segment connected to the feed trajectory segment as the grinding posture corresponding to the trajectory point. The grinding posture can include the grinding radial and grinding axial directions. Using formula (16), the position data of the trajectory point is determined based on the starting point of the machining trajectory segment connected to the feed trajectory segment, the tool radial direction at the starting point of the machining trajectory segment, and the feed distance parameters. Using formula (21), the grinding position corresponding to the trajectory point is determined based on the position data of the trajectory point, the geometric parameters of the grinding wheel, and the grinding radial and grinding axial directions corresponding to the trajectory point.

[0173] To ensure the continuity of the grinding trajectory, the grinding posture corresponding to the trajectory point on the retraction trajectory segment is consistent with the grinding posture corresponding to the end point of the machining trajectory segment to which the retraction trajectory segment is connected. The CNC equipment can determine the position data of the trajectory point on the retraction trajectory segment using formula (17), based on the end point of the machining trajectory segment connected to the retraction trajectory segment, the tool radial distance at the end point of the machining trajectory segment, and the retraction distance parameters. Using formula (22), the grinding position corresponding to the trajectory point is determined based on the position data of the trajectory point, the geometric parameters of the grinding wheel, and the grinding axial and radial directions corresponding to the trajectory point.

[0174] To ensure the continuity of the grinding trajectory, the grinding posture corresponding to the trajectory point on the transition trajectory segment is obtained by uniformly changing the grinding posture between the end point of the retraction trajectory segment connected to the transition trajectory segment and the start point of the infeed trajectory segment. It can be understood that the transition trajectory segment refers to the trajectory segment between the retraction trajectory segment connected to the machining trajectory segment and the infeed trajectory segment connected to the next machining trajectory segment. Therefore, the retraction trajectory segment connected to the transition trajectory segment is the retraction trajectory segment connected to the machining trajectory segment. The infeed trajectory segment connected to the transition trajectory segment is the infeed trajectory segment connected to the next machining trajectory segment. The CNC equipment can use the retraction trajectory segment connected to the machining trajectory segment as the retraction trajectory segment connected to the transition trajectory segment, and the infeed trajectory segment connected to the next trajectory segment as the infeed trajectory segment connected to the transition trajectory segment. For the trajectory point on the transition trajectory segment, the position data of the trajectory point is determined by formula (20) based on the position data of the center of the interpolated arc, the radius parameter, the end point of the retraction trajectory segment connected to the transition trajectory segment, and the start point of the infeed trajectory segment connected to the transition trajectory segment. The grinding posture corresponding to the end point of the retraction trajectory segment connected to the transition trajectory segment is determined as the grinding posture corresponding to the start point of the transition trajectory segment. The grinding posture corresponding to the start point of the infeed trajectory segment connected to the transition trajectory segment is determined as the grinding posture corresponding to the end point of the transition trajectory segment. Using formula (23), the grinding posture corresponding to the trajectory point is determined according to the geometric parameters of the grinding wheel and the grinding postures corresponding to the start and end points of the transition trajectory segment. Using formula (24), the grinding position corresponding to the trajectory point is determined according to the position data of the trajectory point, the geometric parameters of the grinding wheel, and the grinding radial and grinding axial directions corresponding to the trajectory point.

[0175] The CNC equipment can determine the sub-path corresponding to each machining trajectory segment starting from the first intersection point, following the sequence of the start-to-end points of the feed trajectory segments connected to the machining trajectory segment, the machining trajectory segment itself, and the retraction trajectory segments connected to the machining trajectory segment, based on the corresponding grinding posture. For each machining trajectory segment starting from the first intersection point, the sub-path corresponding to each intersection point is determined according to the sequence of the start-to-end points of the transition trajectory segments connected to the feed trajectory segment, the machining trajectory segment itself, and the retraction trajectory segments connected to the machining trajectory segment, based on the corresponding grinding posture. Based on the distribution order of each intersection point and the corresponding sub-path, the grinding trajectory of the grinding wheel when grinding thread teeth on the blank is determined.

[0176] In some embodiments, such as Figure 11 The diagram illustrates a threading tool. The threading tool has threaded teeth and chip grooves. The threaded teeth have tooth grooves and tooth relief faces. The grinding wheel can include a flat grinding wheel and a pointed grinding wheel. The flat grinding wheel is used to grind the tooth relief face. The pointed grinding wheel is used to grind the tooth grooves.

[0177] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0178] Based on the same inventive concept, this application also provides a thread grinding apparatus for implementing the above-described thread grinding method. The solution provided by this apparatus is similar to the solution described in the above method; therefore, the specific limitations of one or more thread grinding apparatus embodiments provided below can be found in the limitations of the thread grinding method described above, and will not be repeated here.

[0179] In one exemplary embodiment, such as Figure 12 As shown, a thread grinding apparatus 1200 is provided, including a determination module 1202 and a planning module 1204.

[0180] The determination module 1202 is used to determine the intersection point between the chip groove cutting line and the thread guide line on the outer cylindrical surface of the blank; determine the circumferential machining range of the machining trajectory segment from the intersection point based on the machining range parameters; determine the axial distribution of the thread guide line along the tool axis within the circumferential machining range as the axial distribution of the machining trajectory segment from the intersection point along the tool axis; and obtain the radial distribution of the machining trajectory segment from the intersection point along the tool radial direction by decreasing the bottom circle radius of the blank with the circumferential deflection angle relative to the intersection point based on the radial clearance angle parameters.

[0181] Planning module 1204 is used to determine the grinding trajectory of the grinding wheel when grinding thread teeth on the blank based on the geometric parameters of the grinding wheel and the radial and axial distribution of the machining trajectory segment.

[0182] In some embodiments, the determining module 1202 is further configured to determine the intersection point between the chip groove cutting line and the thread guide line on the outer cylindrical surface of the blank based on the pitch parameter, the tool diameter parameter, the number of cutting edges parameter, and the helix angle parameter; wherein, the pitch parameter is used to characterize the axial distance between two adjacent segments of thread teeth along the tool axis; the tool diameter parameter is used to characterize the bottom circle diameter of the blank; the number of cutting edges parameter is used to characterize the number of chip grooves; and the helix angle parameter is used to characterize the helix angle of the cutting edge formed by the intersection of the thread teeth and the chip grooves.

[0183] In some embodiments, the determining module 1202 is further configured to, based on an exponential decay coefficient matched with the radial clearance angle parameter, decrease the bottom circle radius of the blank exponentially with respect to the circumferential deflection angle relative to the intersection point, thereby obtaining the radial distribution of the machining trajectory segment from the intersection point along the radial direction of the tool.

[0184] In some embodiments, the planning module 1204 is further configured to: determine an infeed trajectory segment whose endpoint is connected to the starting point of the machining trajectory segment and whose radial offset distance of the tool along the starting point of the machining trajectory segment matches the infeed distance parameter; determine a retraction trajectory segment whose starting point is connected to the ending point of the machining trajectory segment and whose radial offset distance of the tool along the ending point of the machining trajectory segment matches the retraction distance parameter; determine the grinding posture corresponding to the trajectory point on the machining trajectory segment based on the geometric parameters of the grinding wheel and the radial and axial distribution of the machining trajectory segment; and determine the grinding trajectory of the grinding wheel grinding thread teeth on the blank based on the geometric parameters of the grinding wheel, the grinding posture corresponding to the trajectory point on the machining trajectory segment, the infeed trajectory segment, and the retraction trajectory segment.

[0185] In some embodiments, the intersection points are distributed sequentially along the thread guide line; the distribution order of the machining trajectory segments starting from the intersection points is consistent with the distribution order of the intersection points; the planning module 1204 is also used to interpolate based on the end point of the retraction trajectory segment connected to the machining trajectory segment and the starting point of the infeed trajectory segment connected to the next machining trajectory segment in the subsequent distribution order to obtain the transition trajectory segment; based on the geometric parameters of the grinding wheel, the grinding posture corresponding to the trajectory points on the machining trajectory segment, the infeed trajectory segment, the retraction trajectory segment and the transition trajectory segment, the grinding trajectory of the grinding wheel grinding the thread teeth on the blank is determined.

[0186] In some embodiments, the planning module 1204 is further configured to, for each trajectory point on the machining trajectory segment, determine the grinding posture corresponding to the trajectory point based on the geometric parameters of the grinding wheel and the tangent of the machining trajectory segment at the trajectory point; the grinding posture includes a grinding posture representing the attitude of the grinding wheel and a grinding position representing the position of the grinding wheel; the grinding posture corresponding to the starting point of the machining trajectory segment connected to the infeed trajectory segment is determined as the grinding posture corresponding to the trajectory point on the infeed trajectory segment; the grinding posture corresponding to the ending point of the machining trajectory segment connected to the retraction trajectory segment is determined as the retraction posture. The grinding postures corresponding to the trajectory points on the trajectory segment are determined. Interpolation is performed based on the grinding postures corresponding to the endpoints of the retraction trajectory segment connected to the transition trajectory segment and the starting points of the infeed trajectory segment connected to the transition trajectory segment to obtain the grinding postures corresponding to the trajectory points on the transition trajectory segment. For the trajectory points on the infeed trajectory segment, retraction trajectory segment, and transition trajectory segment, the grinding pose corresponding to the trajectory point is determined based on the grinding wheel's geometric parameters and the grinding posture corresponding to the trajectory point. The grinding trajectory of the grinding wheel when grinding thread teeth on the blank is determined based on the grinding pose.

[0187] In some embodiments, the grinding wheel includes a pointed grinding wheel; the planning module 1204 is further configured to determine the grinding pose corresponding to the trajectory point on the machining trajectory segment based on the geometric parameters, depth of cut parameters, and radial and axial distribution of the machining trajectory segment of the pointed grinding wheel; the grinding pose is used to characterize the pose of the pointed grinding wheel when the distance between the grinding point on the outer edge of the pointed grinding wheel and the trajectory point matches the depth of cut parameter, and the radial direction of the grinding wheel at the grinding point is perpendicular to the tangent of the machining trajectory segment at the trajectory point; and the grinding trajectory of the pointed grinding wheel grinding the tooth groove of the thread tooth on the blank is determined based on the grinding pose.

[0188] In some embodiments, the grinding wheel includes a flat grinding wheel; the planning module 1204 is further configured to determine the grinding posture corresponding to the trajectory point on the machining trajectory segment based on the geometric parameters of the flat grinding wheel and the radial and axial distribution of the machining trajectory segment; the grinding posture is used to characterize the posture of the flat grinding wheel when the grinding point on the outer edge of the flat grinding wheel contacts the trajectory point and the radial direction of the grinding wheel at the grinding point is perpendicular to the tangent of the machining trajectory segment at the trajectory point; and the grinding trajectory is determined based on the grinding posture when the flat grinding wheel grinds the tooth flank face of the thread teeth on the blank.

[0189] Each module in the aforementioned thread grinding device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of the CNC machine in hardware form or independent of it, or stored in the memory of the CNC machine in software form, so that the processor can call and execute the operations corresponding to each module.

[0190] In one exemplary embodiment, a CNC machine is provided, the internal structure of which can be shown in the following diagram. Figure 13 As shown, the CNC equipment includes a processor, memory, input / output interface, communication interface, display unit, and input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interface. The processor provides computational 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 the environment for the operation of the operating system and computer programs in the non-volatile storage media. The input / output interface is used for exchanging information between the processor and external devices. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, NFC (Near Field Communication), or other technologies. When the computer program is executed by the processor, it implements a thread grinding method. The display unit of the CNC equipment is used to form a visually visible image and can be a display screen, projection device, or virtual reality imaging device. The display screen can be an LCD screen or an e-ink screen. The input device of the CNC equipment can be a touch layer covering the display screen, or buttons, trackballs, or touchpads set on the housing of the CNC equipment, or external keyboards, touchpads, or mice, etc.

[0191] Those skilled in the art will understand that Figure 13 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 equipment to which the present application is applied. Specific CNC equipment 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 device is also 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 in the above method embodiments.

[0193] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, implements the steps in the above method embodiments.

[0194] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0195] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments described above. Any references to memory, 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, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0196] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0197] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A grinding method for thread cutting tools, characterized in that, The method includes: Determine the intersection point of the chip groove cutting line and the thread guide line on the outer cylindrical surface of the blank; The circumferential processing range of the processing trajectory segment from the intersection point is determined based on the processing range parameters; The axial distribution of the thread guide line along the tool axis within the circumferential machining range is defined as the axial distribution of the machining trajectory segment along the tool axis starting from the intersection point. Based on the radial clearance angle parameter, the radius of the bottom circle of the blank is decreased with the circumferential deflection angle relative to the intersection point to obtain the radial distribution of the machining trajectory segment from the intersection point along the radial direction of the tool. Based on the geometric parameters of the grinding wheel and the radial and axial distribution of the machining trajectory segment, the grinding trajectory of the grinding wheel when grinding thread teeth on the blank is determined.

2. The method according to claim 1, characterized in that, Determining the intersection point between the chip groove cutting line and the thread guide line on the outer cylindrical surface of the blank includes: The intersection point between the chip groove cutting line and the thread guide line on the outer cylindrical surface of the blank is determined based on the pitch parameter, tool diameter parameter, number of cutting edges parameter, and helix angle parameter. Wherein, the pitch parameter is used to characterize the axial distance between two adjacent thread teeth along the tool axis; the tool diameter parameter is used to characterize the bottom circle diameter of the blank; the number of cutting edges parameter is used to characterize the number of chip grooves; and the helix angle parameter is used to characterize the helix angle of the cutting edge formed by the intersection of the thread teeth and the chip grooves.

3. The method according to claim 1, characterized in that, The step of decreasing the bottom circle radius of the blank with respect to the circumferential deflection angle relative to the intersection point based on the radial clearance angle parameter, to obtain the radial distribution of the machining trajectory segment from the intersection point along the tool radial direction, includes: Based on an exponential decay coefficient that matches the radial clearance angle parameter, the radius of the bottom circle of the blank is decreased exponentially with the circumferential deflection angle relative to the intersection point, thus obtaining the radial distribution of the machining trajectory segment along the tool radial direction from the intersection point.

4. The method according to any one of claims 1 to 3, characterized in that, The grinding trajectory of the grinding wheel on the blank is determined based on the geometric parameters of the grinding wheel and the radial and axial distribution of the machining trajectory segments, including: Determine the feed trajectory segment whose endpoint is connected to the starting point of the machining trajectory segment, and whose radial offset distance of the tool along the starting point of the machining trajectory segment matches the feed distance parameter; Determine a tool retraction trajectory segment whose starting point is connected to the ending point of the machining trajectory segment, and whose radial offset distance of the tool along the ending point of the machining trajectory segment matches the tool retraction distance parameter; Based on the geometric parameters of the grinding wheel and the radial and axial distribution of the machining trajectory segment, the grinding posture corresponding to the trajectory point on the machining trajectory segment is determined; The grinding trajectory of the grinding wheel when grinding thread teeth on the blank is determined based on the geometric parameters of the grinding wheel, the grinding posture corresponding to the trajectory point on the machining trajectory segment, the feed trajectory segment, and the retraction trajectory segment.

5. The method according to claim 4, characterized in that, The intersection points are distributed sequentially along the thread guide line; the distribution order of the machining trajectory segments starting from the intersection points is consistent with the distribution order of the intersection points; determining the grinding trajectory of the grinding wheel when grinding thread teeth on the blank based on the geometric parameters of the grinding wheel, the grinding posture corresponding to the trajectory points on the machining trajectory segments, the feed trajectory segment, and the retraction trajectory segment includes: Interpolation is performed based on the end point of the retraction trajectory segment connected to the machining trajectory segment and the start point of the infeed trajectory segment connected to the next machining trajectory segment in the distribution order to obtain the transition trajectory segment; The grinding trajectory of the grinding wheel when grinding thread teeth on the blank is determined based on the geometric parameters of the grinding wheel, the grinding posture corresponding to the trajectory point on the machining trajectory segment, the feed trajectory segment, the retraction trajectory segment, and the transition trajectory segment.

6. The method according to claim 5, characterized in that, The step of determining the grinding pose corresponding to the trajectory points on the machining trajectory segment based on the geometric parameters of the grinding wheel and the radial and axial distribution of the machining trajectory segment includes: For each trajectory point on the machining trajectory segment, the grinding pose corresponding to the trajectory point is determined according to the geometric parameters of the grinding wheel and the tangent of the machining trajectory segment at the trajectory point; the grinding pose includes the grinding pose characterizing the attitude of the grinding wheel and the grinding position characterizing the position of the grinding wheel. The step of determining the grinding trajectory of the grinding wheel when grinding thread teeth on the blank based on the geometric parameters of the grinding wheel, the grinding posture corresponding to the trajectory points on the machining trajectory segment, the feed trajectory segment, the retraction trajectory segment, and the transition trajectory segment includes: The grinding posture corresponding to the starting point of the machining trajectory segment connected to the infeed trajectory segment is determined as the grinding posture corresponding to the trajectory point on the infeed trajectory segment. The grinding posture corresponding to the end point of the machining trajectory segment connected to the retraction trajectory segment is determined as the grinding posture corresponding to the trajectory point on the retraction trajectory segment. Interpolation is performed based on the grinding posture corresponding to the end point of the retraction trajectory segment connected to the transition trajectory segment and the grinding posture corresponding to the start point of the infeed trajectory segment connected to the transition trajectory segment to obtain the grinding posture corresponding to the trajectory point on the transition trajectory segment. For the trajectory points on the feed trajectory segment, the retraction trajectory segment, and the transition trajectory segment, the grinding posture corresponding to the trajectory point is determined according to the geometric parameters of the grinding wheel and the grinding posture corresponding to the trajectory point. The grinding trajectory of the grinding wheel when grinding thread teeth on the blank is determined based on the grinding posture.

7. The method according to any one of claims 1 to 3, characterized in that, The grinding wheel includes a sharp-angled grinding wheel; determining the grinding trajectory of the grinding wheel when grinding thread teeth on the blank based on the geometric parameters of the grinding wheel and the radial and axial distribution of the machining trajectory segment includes: Based on the geometric parameters and depth-of-cut parameters of the pointed grinding wheel, as well as the radial and axial distribution of the machining trajectory segment, the grinding pose corresponding to the trajectory point on the machining trajectory segment is determined. The grinding pose is used to characterize the pose of the pointed grinding wheel when the distance between the grinding point on the outer edge of the pointed grinding wheel and the trajectory point matches the depth-of-cut parameter, and the radial direction of the grinding wheel at the grinding point is perpendicular to the tangent of the machining trajectory segment at the trajectory point. The grinding trajectory of the sharp-angled grinding wheel when grinding the groove of the threaded teeth on the blank is determined based on the grinding posture.

8. The method according to any one of claims 1 to 3, characterized in that, The grinding wheel includes a flat grinding wheel; determining the grinding trajectory of the grinding wheel when grinding thread teeth on the blank based on the geometric parameters of the grinding wheel and the radial and axial distribution of the machining trajectory segment includes: Based on the geometric parameters of the flat grinding wheel and the radial and axial distribution of the machining trajectory segment, the grinding posture corresponding to the trajectory point on the machining trajectory segment is determined; the grinding posture is used to characterize the posture of the flat grinding wheel when the grinding point on the outer edge of the flat grinding wheel is in contact with the trajectory point, and the radial direction of the grinding wheel at the grinding point is perpendicular to the tangent of the machining trajectory segment at the trajectory point; The grinding trajectory of the flat grinding wheel when grinding the tooth back face of the threaded tooth on the blank is determined based on the grinding posture.

9. A grinding apparatus for threaded cutting tools, characterized in that, The device includes: The determination module is used to determine the intersection point between the chip groove cutting line and the thread guide line on the outer cylindrical surface of the blank; determine the circumferential machining range of the machining trajectory segment from the intersection point based on the machining range parameters; determine the axial distribution of the thread guide line along the tool axis within the circumferential machining range as the axial distribution of the machining trajectory segment from the intersection point along the tool axis; and obtain the radial distribution of the machining trajectory segment from the intersection point along the tool radial direction by decreasing the bottom circle radius of the blank with respect to the circumferential deflection angle relative to the intersection point based on the radial clearance angle parameters. The planning module is used to determine the grinding trajectory of the grinding wheel when grinding thread teeth on the blank, based on the geometric parameters of the grinding wheel and the radial and axial distribution of the machining trajectory segment.

10. A numerically controlled device, 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 8.

Images