A tool mounting model, a tool cutting edge design method and system

Abstract

This invention provides a tool mounting model, a tool cutting edge design method, and a system. Specifically, the tool has the same structure as a gear turning cutter, employing a cylindrical tool body structure. The cutting edge is located on the end face of the tool, and the cutting edge uses a planar rake face, with the rake face approximately perpendicular to the helix angle of the cutting teeth. The tool and gear workpiece are mounted in space using a gear turning machining method. There is no interference between the side of the tool and the chamfered machining surface of the gear workpiece. The cutting edge of the tool teeth is aligned with the tooth groove of the gear workpiece, and the tool has an installation distance relative to the end face of the gear workpiece to achieve interference-free machining of the chamfered profile of the gear workpiece end face. This invention fundamentally guarantees the consistency of machining accuracy from the machining principle, and significantly improves the manufacturing economy, usage economy, and processability of the tool.

Description

Technical Field

[0001] This invention belongs to the field of gear machining technology, specifically to a tool mounting model, a tool cutting edge design method and system. Background Technology

[0002] With the vigorous development of new energy vehicles, new requirements and challenges have been placed on the manufacturing precision and processes of transmission system gears. To reduce noise in high-speed transmission gear systems and improve the fatigue life of gears, it is necessary to perform chamfering on the gear end face profile with high consistency. Traditional machining methods based on meshing and extrusion can cause local structural deformation of the tooth surface, affecting meshing performance; machining methods based on tooth surface profile trajectory milling are inefficient; and chamfering methods based on cyclone milling, due to the use of straight-edged tools, can only produce chamfered structures but are difficult to meet the uniformity requirements of the chamfer profile. In contrast, driven by the manufacturing philosophy of high efficiency and concentrated processes in new energy vehicle manufacturing, a continuous chamfering cutting method for cylindrical gear end faces based on hobbing has been proposed (ZL202111267144.X "A High-Speed ​​Continuous Cutting Method for Chamfering Gear End Face Profile"). Due to its advantages such as not occupying an independent machine tool and being able to be integrated with the hobbing process, it has strong market vitality. However, the hobbing chamfering tool used in the above patent has axially distributed cutting teeth, generally only 2 to 4 teeth. To perform a complete cutting traverse of the workpiece tooth groove, the tool needs to rotate a large number of times, resulting in low processing efficiency. At the same time, the tool has few teeth and a short lifespan. Summary of the Invention

[0003] To address the problems existing in the prior art, this invention provides a tool mounting model, a tool cutting edge design method, and a system. The cutting edge of the tool teeth is redirected to the direction of the tool's axial end face, similar to a gear turning tool. This allows for a higher density of tool teeth, thereby further improving machining efficiency. From the perspective of the tool's entire lifecycle, compared to the current conical tool body, a reasonable cylindrical tool body structure is proposed. A cylindrical tool body structure and a gear workpiece mounting model are also proposed, enabling interference-free machining of the cylindrical gear end face chamfer using the cylindrical tool body. This fundamentally guarantees consistent machining accuracy from a machining principle perspective, significantly improving the manufacturing economy, usage economy, and processability of the tool.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a gear chamfering tool mounting model, specifically:

[0005] The tool has the same structure as the gear cutting tool, adopting a cylindrical tool body structure. The cutting edge of the tool is located on the end face of the tool. The cutting edge adopts a planar rake face, and the rake face of the cutting edge is approximately perpendicular to the helix angle of the cutting tooth.

[0006] The cutting tool and the gear workpiece are installed in space using a gear turning machining method. There is no interference between the side of the cutting tool and the chamfered machining surface of the gear workpiece. The cutting edge of the cutting tool teeth is aligned with the tooth groove of the gear workpiece. The cutting tool has an installation distance relative to the end face of the gear workpiece to achieve interference-free machining of the chamfered profile of the end face of the gear workpiece.

[0007] Furthermore, to achieve the installation of the cutting tool and gear workpiece in space using a gear turning method, there must be an axial angle Σ and a mounting center distance Ec between the cutting tool and the gear workpiece. The calculation of the axial angle Σ and the mounting center distance Ec is as follows:

[0008] Axial angle

[0009] Installation center distance

[0010] Among them, the equivalent axis intersection angle Workpiece tool setting angle , kc For the direction of the tool rotation, βg For the helix angle of the gear workpiece, βc The helix angle of the cutting tool. λ The process angle that separates the cutting tool and the gear. Rg The pitch circle radius of the gear workpiece. Rc The tool pitch circle radius, φc The included angle at which the tool intervenes in the chamfering cut.

[0011] Furthermore, the mounting distance between the tool and the gear end face is the axial distance Ea between the origin of the tool coordinate system and the origin of the gear workpiece coordinate system, specifically:

[0012] Axial distance

[0013] in, Rc The tool pitch circle radius, φc The included angle at which the tool intervenes in the chamfering cut.

[0014] Furthermore, the tool is offset in the direction perpendicular to the installation center distance to ensure no interference between the tool side and the chamfered surface of the gear workpiece. The offset is achieved using axial offset. Ee Specifically, it means:

[0015] Axis offset

[0016] in, Rg The pitch circle radius of the gear workpiece. Rc The tool pitch circle radius, φc The included angle at which the tool intervenes in the chamfering cut; the workpiece tool setting angle. Equivalent axis intersection angle λ is the process angle at which the cutting tool and gear separate; kc For the direction of the tool rotation, βg For the helix angle of the gear workpiece, βc The helix angle of the cutting tool.

[0017] Furthermore, by limiting the initial tool setting angle Ф between the gear workpiece and the cutting tool, the cutting edge of the cutting tool teeth is aligned with the tooth groove of the gear workpiece.

[0018] This invention also provides a method for designing the cutting edge of a cutting tool, the specific steps of which are as follows:

[0019] S1 obtains the above-mentioned gear chamfering machining tool mounting model, which limits the tool cutting edge to be located on the end face of the tool, the cutting edge adopts a planar rake face, and the rake face of the tool cutting edge is approximately perpendicular to the helix angle of the tool teeth;

[0020] S2 obtains the intersection lines C1(u) and C2(u) of the gear chamfer edge line G1(u) and the gear end face chamfer profile line G2(u) with the rake face SR of the cutter tooth when the gear workpiece moves relative to the cutter in space;

[0021] S3 intersects the cutting edge SR on the rake face of the cutting tooth at the corresponding point C1(u) on the line C1(u) and C2(u). i ) and C2(u i Connect the two points, and take the midpoint E(u) of the line connecting the two points. i According to point C1(u) i ) and C2(u i ) to the midpoint E(u i The evaluation function is established based on the distance. f e ;

[0022] S4 uses the initial tool setting angle Ф as the evaluation function. f e The variables are used to establish an optimization problem. A numerical search method is employed to obtain the initial tool setting angle Ф that minimizes the numerical value of the optimization problem, thus obtaining the optimal midpoint E(u). i );

[0023] S5 will obtain the midpoint E(u) i By sequentially connecting the cutting edges, the fitted cutting edge curve E(u) is obtained. On the cylindrical tool body structure, the cutting edge curve is swept according to the set helical lead to obtain the tool tooth structure.

[0024] Furthermore, in S2, the intersection point of each point on the gear chamfering edge line G1(u) and the gear end face chamfering profile line G2(u) with the rake face SR of the cutter tooth is determined by the following method:

[0025] Specifically, taking a point G(u) on the gear workpiece as an example, its spatial motion relative to the cutting tool can be expressed as a time-space equation. t The homogeneous coordinate transformation matrix M for variables gc :

[0026]

[0027] in: ;

[0028] ;

[0029] ;

[0030] Σ The angle between the axes, Ec For installation center distance, Ee This is the axis offset. Ea This is the axial distance. Zg This refers to the number of teeth on the gear. Zc This refers to the number of teeth on the cutting tool.

[0031] The intersection of this point and the rake face can be expressed as a function of the time variable. t The equation is as follows:

[0032]

[0033] Where Oc and Nc are the rake face S of the cutting edge. R A point on the plane and its normal vector;

[0034] The variable t corresponding to the intersection point is obtained through a numerical search algorithm. c Solving this problem allows us to determine the coordinates of the intersection point, C(u) = M. gc (t c )·G(u).

[0035] Furthermore, in S3, the corresponding points C1(u) on the intersection lines C1(u) and C2(u) on the rake face SR of the cutting teeth are... i ) and C2(u i Connect the two points, and take the midpoint E(u) of the line connecting the two points. i ), all points C1(u i ) and C2(u i ) to the midpoint E(u i The sum of squares of ) is used as the evaluation function f e Specifically:

[0036]

[0037] Where Ф is the initial tool setting angle, Σ The angle between the axes, EcFor installation center distance, Ee This is the axis offset. Ea This is the axial distance. Zg This refers to the number of teeth on the gear. Zc This represents the number of teeth on the cutting tool.

[0038] Furthermore, in S4, the optimization problem is described as follows:

[0039] min .

[0040] The present invention also provides a design system for the cutting edge of a cutting tool, comprising:

[0041] The tool parameter limiting module is used to limit the location of the tool cutting edge on the end face of the tool. The cutting edge adopts a planar rake face, and the rake face of the tool cutting edge is approximately perpendicular to the helix angle of the tool teeth.

[0042] The intersection line acquisition module is used to acquire the above-mentioned gear chamfering machining tool installation model, and obtain the intersection lines C1(u) and C2(u) of the gear chamfering edge line G1(u) and the gear end face chamfering profile line G2(u) with the rake face SR of the cutter tooth when the gear workpiece moves relative to the tool in space;

[0043] The evaluation function establishment module is used to establish the corresponding points C1(u) on the intersection lines C1(u) and C2(u) on the rake face SR of the cutting tooth. i ) and C2(u i Connect the two points, and take the midpoint E(u) of the line connecting the two points. i According to point C1(u) i ) and C2(u i ) to the midpoint E(u i The evaluation function is established based on the distance. f e ;

[0044] The optimization problem-setting module is used to evaluate the initial tool-setting angle Ф as the evaluation function. f e The variables are used to establish an optimization problem. A numerical search method is employed to obtain the initial tool setting angle Ф that minimizes the numerical value of the optimization problem, thus obtaining the optimal midpoint E(u). i );

[0045] The tooth structure fabrication module is used to prepare the obtained midpoint E(u) i By sequentially connecting the cutting edges, the fitted cutting edge curve E(u) is obtained. On the cylindrical tool body structure, the cutting edge curve is swept along the tool according to the set helical lead to obtain the tool tooth structure.

[0046] Compared with the prior art, the present invention has at least the following beneficial effects:

[0047] This invention provides a tool mounting model. From the perspective of the entire life cycle of the tool, compared with the current conical tool body, the tool of this invention adopts a cylindrical tool body structure, which converts the cutting edge of the tool teeth to the direction of the tool's axial end face, similar to a gear turning tool. This allows for a higher density of the tool teeth, increasing the number of teeth involved in cutting, which on the one hand further improves processing efficiency, and on the other hand extends the tool's service life. Furthermore, tool grinding does not cause changes in the cutting edge profile, ensuring the consistency of the chamfering quality of gear workpieces. At the same time, the tooth profile grinding of cylindrical tools is simpler and can be directly achieved by forming or generating machining, unlike the increased processing cycle and difficulty caused by separately processing the two tooth surfaces of conical tools.

[0048] Furthermore, traditional gear chamfering tools often use extrusion fitting methods, which can cause local deformation of the tooth surface, worsen the gear's meshing contact performance, reduce lifespan, and increase noise. In the tool mounting model of this invention, the tool and gear workpiece are mounted in space using a gear turning method. During machining, the tool cuts the gear end face profile chamfer through meshing motion. This not only achieves high machining efficiency but also ensures that the local morphological changes of the tooth surface caused by extrusion are avoided, thus not affecting the gear's meshing performance. Moreover, it limits the interference between the tool side and the chamfering surface of the gear workpiece, with the cutting edge of the tool teeth aligned with the gear workpiece tooth groove, and the tool having an installation distance relative to the gear workpiece end face. This achieves interference-free machining of the cylindrical gear end face profile chamfer by the cylindrical tool body, fundamentally guaranteeing the consistency of machining accuracy from the machining principle, and significantly improving the manufacturing economy, usage economy, and processability of the tool.

[0049] The installation model of this invention corresponds to a small machine tool axis intersection angle, making it applicable to gear turning machines and mill-turn machining centers, etc., and providing good basic equipment support conditions for application.

[0050] Based on the aforementioned installation model and the relative motion relationship between the gear workpiece and the cutting tool, this invention specifically designs the cutting edge of the cutting tool. By solving the intersection line of the gear chamfer edge line and the gear end face chamfer profile line with the cutting tool rake face SR, the cutting edge curve E(u) is obtained through fitting. Based on the cutting edge curve, the cutting is swept according to the set helical lead to obtain the cutting tool tooth structure. The cutting tool tooth structure of this invention is a helical sweep structure with equal radius, which greatly improves the manufacturing convenience, operability, and manufacturing economy of this type of tool, ensuring its competitiveness in the market. Attached Figure Description

[0051] Figure 1 This is the processing and installation model of the present invention.

[0052] Figure 2This is a schematic diagram illustrating the calculation principle of the intersection line of the gear chamfering structure relative to the rake face of the cutting tool in this invention.

[0053] Figure 3 This is a schematic diagram of the meshing calculation model of the cutting edge of the present invention.

[0054] Figure 4 This is a schematic diagram of the cylindrical blade structure obtained by the present invention. Detailed Implementation

[0055] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments. All equivalent modifications made based on the technical solutions of this application fall within the protection scope of the present invention.

[0056] The purpose of this invention is to provide a machining and installation model for chamfering the end face profile of cylindrical gears based on a gear turning machining mode, and a design method for such a tool using a cylindrical tool body structure.

[0057] For details, please refer to the following: Figure 1 This invention provides a gear chamfering tool mounting model for chamfering the end face profile of cylindrical gears. The mounting model requires the following data to be determined:

[0058] The minimum distance between the gear rotation axis and the tool rotation axis, i.e., the center distance. Ec ;

[0059] The angle between the gear rotation axis and the tool rotation axis is called the shaft angle. Σ ;

[0060] Axial distance between the origin of the tool coordinate system and the origin of the workpiece coordinate system Ea ;

[0061] The distance between the origin of the tool coordinate system and the origin of the workpiece coordinate system in the direction perpendicular to the minimum distance. Ee ;

[0062] The rotation angle Ф of the tool coordinate system relative to the workpiece coordinate system about the z-axis;

[0063] The specific setup method for installing the model is as follows:

[0064] 1) Obtaining gear workpiece parameters includes: number of gear teeth. Zg Pitch circle radius Rg helix angle βg Rotation direction kg (Right-hand = 1, Left-hand = -1, Straight tooth = 0), Gear chamfer edge curve G1(u) and gear chamfer end face curve G2(u);

[0065] 2) The cutting tool adopts the same structure as a gear-turning cutter, that is, the cutting edge is located on the end face of the tool, and the tool as a whole resembles a gear with a large number of teeth. Based on this, further requirements are needed:

[0066] (a) The tool body adopts a cylindrical structure;

[0067] (b) The cutting edge of the tool adopts a planar rake face;

[0068] (c) The rake face of the cutting edge of the tool is approximately perpendicular to the helix angle of the cutting teeth by means of the inclination angle.

[0069] Obtaining tool parameters includes: the number of teeth selected based on experience. Zc Pitch circle radius Rc helix angle βc Rotation direction kc (Right-handed = 1, Left-handed = -1, Straight tooth = 0), Cutting face of the cutting tooth SR ;

[0070] 3) The tool and gear workpiece should be installed in space similar to the gear turning process, ensuring that there is an axial angle between the tool and the workpiece. Σ and installation center distance Ec The angle between the gear rotation axis and the tool rotation axis is called the axis angle. Σ The minimum distance between the gear rotation axis and the tool rotation axis is the installation center distance. Ec The specific calculation is as follows:

[0071] Axial angle

[0072] Installation center distance

[0073] Among them, the equivalent axis intersection angle Workpiece tool setting angle λ is the process angle at which the cutting tool and gear separate, typically selected within the range of 0.5° to 3°. φc The included angle at which the tool intervenes in the chamfering cut;

[0074] 2) To ensure the chamfering of the gear end face profile by the cutting tool, it is necessary to limit the mounting distance of the tool relative to the gear end face, and the axial distance between the origin of the tool coordinate system and the origin of the gear workpiece coordinate system. Ea The specific calculation of the installation distance is as follows:

[0075] Axial distance

[0076] in, φc The included angle for the tool to engage in chamfering cutting is generally selected within the range of 45°.

[0077] 3) To achieve interference-free cutting with a cylindrical tool body structure, the tool needs to be positioned at the installation center distance. Ec The tool is positioned perpendicular to the workpiece coordinate system, and an installation offset is set to ensure separation between the tool side and the chamfered surface of the gear workpiece without interference. Therefore, it is necessary to determine the distance between the origin of the tool coordinate system and the origin of the gear workpiece coordinate system in the direction perpendicular to the minimum distance. Ee The calculation is as follows:

[0078] Axis offset

[0079] Among them, the equivalent axis intersection angle Workpiece tool setting angle λ is the process angle at which the tool and gear separate, generally selected in the range of 0.5° to 3°; φc is the angle at which the tool intervenes in the chamfering cut, generally selected in the range of 45°.

[0080] 4) The initial tool setting angle between the gear workpiece and the tool, i.e. the rotation angle Ф of the tool coordinate system relative to the workpiece coordinate system around the z-axis, is limited to ensure that the cutting edge of the tool teeth is aligned with the tooth groove of the gear workpiece, so that the chamfering of the symmetrical structure can be completed.

[0081] In summary, a tool mounting model for chamfering the end face profile of cylindrical gears is obtained.

[0082] This invention also provides a method for designing the cutting edge of a cutting tool. Based on the aforementioned mounting model, the relative motion relationship between the cutting tool and the gear workpiece is determined. The cutting edge curve of the cutting tool is calculated by combining the gear chamfer edge curve G1(u) and the gear chamfer end face curve G2(u), as detailed below:

[0083] 1) Based on the above installation model, the gear and the cutter perform meshing motion at a fixed speed ratio. At this time, the gear chamfer edge line G1(u) and the gear end face chamfer profile line G2(u) move relative to the cutter in space, and form intersection lines C1(u) and C2(u) with the rake face SR of the cutter tooth. Specifically, taking a point G(u) on the gear as an example, its spatial motion relative to the cutter can be expressed as a homogeneous coordinate transformation matrix M with time t as the variable. gc :

[0084]

[0085] in: ;

[0086] ;

[0087] ;

[0088] The intersection of this point and the rake face can be expressed as a function of the time variable. tThe equation is as follows:

[0089]

[0090] Where Oc and Nc are the rake face S of the cutting edge. R A point on the surface and its normal vector.

[0091] For this formula, the variables corresponding to the intersection points can be determined using a numerical search algorithm. t c Solving this problem allows us to determine the coordinates of the intersection point, C(u) = M. gc (t c )·G(u).

[0092] like Figure 2 As shown, the solution of the intersection point of each point on the gear chamfering edge line G1(u) and the gear end face chamfering profile line G2(u) with the rake face SR of the cutter tooth is finally obtained, and the corresponding intersection lines C1(u) and C2(u) are obtained.

[0093] 2) For the intersection lines C1(u) and C2(u) corresponding to the gear chamfering edge line G1(u) and the gear end face chamfering profile line G2(u), connect the points on the rake face SR of the cutter tooth according to the corresponding serial numbers, and then take the midpoint E(u) of the line connecting the corresponding points on the intersection lines C1(u) and C2(u). i ),like Figure 3 As shown.

[0094] At the same time, the distance between each point on the intersection lines C1(u) and C2(u) and the determined midpoint is recorded, and the sum of the squares of all point distances is used as an evaluation function. f e It is used to evaluate the consistency of the cutting edge curves generated on the gear chamfering edge line G1(u) and the gear end face chamfering profile line G2(u).

[0095]

[0096] (5) The consistency of the corresponding cutting edges generated on the gear chamfering edge line G1(u) and the gear end face chamfering profile line G2(u) is expressed as an optimization problem about the initial tool setting angle. Due to the installation parameters Ф, Σ , Ec , Ee and Ea Generally, given a specific variable, the initial tool setting angle Ф is adjusted to ensure that the cutting edges generated by the gear chamfering edge line and the gear end face chamfering profile line are basically coincident. This guarantees good quality cutting of the gear end face chamfering profile. Specifically:

[0097] The tool cutting edge curves generated on the gear chamfering edge line G1(u) and the gear end face chamfering profile line G2(u) are fitted respectively. An optimization problem is constructed with the initial tool setting angle in the machining and installation model parameters as the variable, with the goal of minimizing the sum of squared residuals after fitting. The optimization problem is described as follows:

[0098] min

[0099] (6) The above optimization problem is solved by numerical search method to obtain the initial tool setting angle Ф. At the same time, the determined midpoint E(u) is obtained. The obtained midpoints E(u) are connected in sequence to obtain the fitted cutting edge curve E(u).

[0100] (7) On the cylindrical tool body structure, the complete tool tooth structure can be determined by sweeping according to the set spiral lead based on the cutting edge curve.

[0101] Example

[0102] This invention provides a machining model and tool design method for chamfering the end face profile of cylindrical gears using a gear turning process. It proposes a machining and installation model similar to gear turning for chamfering the end face profile of cylindrical gears, and further provides a design method for cylindrical chamfering cutting tools.

[0103] For a specific implementation of the present invention, the known input conditions are as follows:

[0104] Gear: Number of teeth Zg Pitch circle radius Rg helix angle βg Rotation direction kg (Right-handed = 1, Left-handed = -1, Straight tooth = 0), Gear chamfer edge curve G1(u) and gear chamfer end face curve G2(u);

[0105] Cutting tool: Number of teeth selected based on experience Zc Pitch circle radius Rc helix angle βg Rotation direction kc (Right-handed = 1, Left-handed = -1, Straight tooth = 0), Rake face SR;

[0106] Installation-related empirical parameters: the included angle at which the tool intervenes in the chamfering cut. φc The process angle formed by the separation of the cutting tool and the gear λ ;

[0107] Based on the above input, the machining installation model and tool design process of the present invention are as follows:

[0108] Step 1: Calculate the processing and installation parameters as follows:

[0109] Axial angle

[0110] center distance

[0111] Axial distance

[0112] Axis offset

[0113] The initial tool setting angle Ф is to be determined as a subsequent optimization variable;

[0114] Among them, the equivalent axis intersection angle Workpiece tool setting angle

[0115] Generally, the included angle φc for the tool to engage in chamfering can be selected within the range of 45°; the process included angle λ for the tool and gear to separate can be selected within the range of 0.5° to 3°.

[0116] Step 2: Perform basic calculations of the cutting edge curve based on the gear chamfering edge line G1(u) and the gear end face chamfering profile line G2(u).

[0117] The solution for the intersection of each point G(u) on the gear chamfering edge line G1(u) and the gear end face chamfering profile line G2(u) with the rake face of the cutter tooth is obtained through a numerical search algorithm using the motion time variable. tc Solve the following equation:

[0118]

[0119] Where Oc and Nc are the rake face S of the cutting edge. R A point on the plane and its normal vector; M gc This is the spatial motion transformation matrix from the gear coordinate system to the tool coordinate system driven by machining motion, as detailed below:

[0120]

[0121]

[0122]

[0123]

[0124] The intersection point C(u) and the rake face SR is obtained as M. gc ( tc )·G(u);

[0125] Step 3: Perform fitting calculations for the cutting edge curve. For the intersection points C1(u) and C2(u) of the gear chamfering edge line G1(u) and the gear end face chamfering profile line G2(u), perform fitting point by point on the rake face SR according to the corresponding sequence number, that is, take the midpoint E(u) of the line connecting the corresponding points. i) .

[0126] Step 4: Calculate the evaluation function of the fitted cutting edge. f e Record each point C1(u) i ) or C2(u i ) and determine the midpoint E(u) i The distance to ) is used as the evaluation function, with the sum of the squares of the distances to all points. f e It is used to evaluate the consistency of the cutting edge curves generated on the gear chamfering edge line G1(u) and the gear end face chamfering profile line G2(u).

[0127]

[0128] Step 5: Solve the optimization problem with the initial tool setting angle Ф as the variable and the goal of minimizing the consistency of the fitting cutting edge. A general numerical search can be used to solve this problem. During the solution process, if necessary, perform dynamic adjustment calculations for cutting as described in Step 2 until an acceptable numerical solution is obtained, and then proceed to Step 6.

[0129] min.

[0130] Step 6: Based on the optimization results obtained in the previous step, obtain (a) the initial tool setting angle Ф in the machining installation parameters; and (b) the fitted cutting edge curve. The cutting edge curve is swept according to the helical structure of the cutting teeth to construct cylindrical tool teeth (e.g., ...). Figure 4 As shown in the figure, this enables the digital design of cutting tools.

[0131] This invention provides a design system for the cutting edge of a cutting tool, comprising:

[0132] The tool parameter limiting module is used to limit the location of the tool cutting edge on the end face of the tool. The cutting edge adopts a planar rake face, and the rake face of the tool cutting edge is approximately perpendicular to the helix angle of the tool teeth.

[0133] The intersection line acquisition module is used to acquire the above-mentioned gear chamfering machining tool installation model, and obtain the intersection lines C1(u) and C2(u) of the gear chamfering edge line G1(u) and the gear end face chamfering profile line G2(u) with the rake face SR of the cutter tooth when the gear workpiece moves relative to the tool in space;

[0134] The evaluation function establishment module is used to establish the corresponding points C1(u) on the intersection lines C1(u) and C2(u) on the rake face SR of the cutting tooth. i ) and C2(u i Connect the two points, and take the midpoint E(u) of the line connecting the two points. i According to point C1(u) i ) and C2(u i ) to the midpoint E(u i The evaluation function is established based on the distance. f e ;

[0135] The optimization problem-setting module is used to evaluate the initial tool-setting angle Ф as the evaluation function. f e The variables are used to establish an optimization problem. A numerical search method is employed to obtain the initial tool setting angle Ф that minimizes the numerical value of the optimization problem, thus obtaining the optimal midpoint E(u). i );

[0136] The tooth structure fabrication module is used to prepare the obtained midpoint E(u) i By sequentially connecting the cutting edges, the fitted cutting edge curve E(u) is obtained. On the cylindrical tool body structure, the cutting edge curve is swept along the tool according to the set helical lead to obtain the tool tooth structure.

Claims

1. A tool mounting model for gear chamfering, characterized in that, Specifically: The tool has the same structure as the gear turning tool, adopting a cylindrical tool body structure. The cutting edge of the tool is located on the end face of the tool. The cutting edge adopts a planar rake face, and the rake face of the cutting edge is approximately perpendicular to the helix angle of the cutting tooth. The cutting tool and the gear workpiece are installed in space using a gear turning machining method. There is no interference between the side of the cutting tool and the chamfered machining surface of the gear workpiece. The cutting edge of the cutting tool teeth is aligned with the tooth groove of the gear workpiece. The cutting tool has an installation distance relative to the end face of the gear workpiece to achieve interference-free machining of the chamfered profile of the end face of the gear workpiece. Set a mounting offset for the tool in the direction perpendicular to the mounting center distance to ensure no interference between the tool side and the chamfered surface of the gear workpiece. The mounting offset is based on the axial offset. Ee Specifically, it means: Axis offset in, Rg The pitch circle radius of the gear workpiece. Rc The tool pitch circle radius, φc The included angle at which the tool intervenes in the chamfering cut; the workpiece tool setting angle. Equivalent axis intersection angle λ is the process angle at which the cutting tool and gear separate; kc For the direction of the tool rotation, βg For the helix angle of the gear workpiece, βc The helix angle of the cutting tool; By limiting the initial tool setting angle Ф between the gear workpiece and the tool, the cutting edge of the tool teeth is aligned with the tooth groove of the gear workpiece. The mounting distance between the cutting tool and the end face of the gear workpiece is the axial distance Ea between the origin of the cutting tool coordinate system and the origin of the gear workpiece coordinate system, specifically: Axial distance in, Rc The tool pitch circle radius, φc The included angle at which the tool intervenes in the chamfering cut.

2. The gear chamfering tool mounting model according to claim 1, characterized in that, To achieve the installation of the cutting tool and gear workpiece in space using a gear turning method, the cutting tool and gear workpiece must have an axial intersection angle Σ and a mounting center distance Ec. The calculation of the axial intersection angle Σ and the mounting center distance Ec is as follows: Axial angle Installation center distance Among them, the equivalent axis intersection angle Workpiece tool setting angle , kc For the direction of the tool rotation, βg For the helix angle of the gear workpiece, βc The helix angle of the cutting tool. λ The process angle that separates the cutting tool and the gear. Rg The pitch circle radius of the gear workpiece. Rc The tool pitch circle radius, φc The included angle at which the tool intervenes in the chamfering cut.

3. A method for designing the cutting edge of a cutting tool, characterized in that, The specific steps are as follows: S1 obtains a gear chamfering machining tool mounting model according to any one of claims 1 to 2, which defines the tool cutting edge as being located on the end face of the tool, the cutting edge adopts a planar rake face, and the rake face of the tool cutting edge is approximately perpendicular to the helix angle of the tool teeth; S2 obtains the intersection lines C1(u) and C2(u) of the gear chamfer edge line G1(u) and the gear end face chamfer profile line G2(u) with the rake face SR of the cutter tooth when the gear workpiece moves relative to the cutter in space; S3 intersects the cutting edge SR on the rake face of the cutting tooth at the corresponding point C1(u) on the line C1(u) and C2(u). i ) and C2(u i Connect the two points, and take the midpoint E(u) of the line connecting the two points. i According to point C1(u) i ) and C2(u i ) to the midpoint E(u i The evaluation function is established based on the distance. f e ; S4 uses the initial tool setting angle Ф as the evaluation function. f e The variables are used to establish an optimization problem. A numerical search method is employed to obtain the initial tool setting angle Ф that minimizes the numerical value of the optimization problem, thus obtaining the optimal midpoint E(u). i ); S5 connecting the obtained midpoints E(u i ) in sequence to obtain the fitted cutting edge curve E(u), and based on the cutting edge curve, the tool teeth structure is obtained by sweeping on the cylindrical tool body structure according to the set helix lead.

4. The method for designing the cutting edge of a cutting tool according to claim 3, characterized in that, In S2, the intersection point of each point on the gear chamfer edge line G1(u) and the gear end face chamfer profile line G2(u) with the rake face SR of the cutter tooth is determined by the following method: Specifically, taking a point G(u) on the gear workpiece as an example, its spatial motion relative to the cutting tool can be expressed as a time-space equation. t The homogeneous coordinate transformation matrix M for variables gc : in: ; ； ； Σ The angle between the axes, Ec For installation center distance, Ee This is the axis offset. Ea It is the axial distance. Zg This refers to the number of teeth on the gear. Zc This refers to the number of teeth on the cutting tool. The intersection of this point and the rake face can be expressed as a function of the time variable. t The equation is as follows: Where Oc and Nc are the rake face S of the cutting edge. R A point on the plane and its normal vector; The variable t corresponding to the intersection point is obtained through a numerical search algorithm. c Solving this problem allows us to determine the coordinates of the intersection point, C(u) = M. gc (t c )·G(u).

5. The method for designing the cutting edge of a cutting tool according to claim 3, characterized in that, In S3, the points C1(u) and C2(u) on the intersection line C1(u) and C2(u) on the rake face SR of the cutting tooth are intersected. i ) and C2(u i Connect the two points, and take the midpoint E(u) of the line connecting the two points. i ), all points C1(u i ) and C2(u i ) to the midpoint E(u i The sum of squares of ) is used as the evaluation function f e Specifically: Where Ф is the initial tool setting angle, Σ The angle between the axes, Ec For installation center distance, Ee This is the axis offset. Ea It is the axial distance. Zg This refers to the number of teeth on the gear. Zc This represents the number of teeth on the cutting tool.

6. The method for designing the cutting edge of a cutting tool according to claim 3, characterized in that, In S4, the optimization problem is described as follows: min 。 7. A design system for the cutting edge of a cutting tool, characterized in that, include: The tool parameter limiting module is used to limit the location of the tool cutting edge on the end face of the tool. The cutting edge adopts a planar rake face, and the rake face of the tool cutting edge is approximately perpendicular to the helix angle of the tool teeth. The intersection line acquisition module is used to acquire the gear chamfering tool mounting model according to any one of claims 1 to 2, and obtain the intersection lines C1(u) and C2(u) of the gear chamfering edge line G1(u) and the gear end face chamfering profile line G2(u) with the rake face SR of the cutter tooth when the gear workpiece moves relative to the cutter in space; The evaluation function establishment module is used to establish the corresponding points C1(u) on the intersection lines C1(u) and C2(u) on the rake face SR of the cutting tooth. i ) and C2(u i Connect the two points, and take the midpoint E(u) of the line connecting the two points. i According to point C1(u) i ) and C2(u i ) to the midpoint E(u i The evaluation function is established based on the distance. f e ; The optimization problem-setting module is used to evaluate the initial tool-setting angle Ф as the evaluation function. f e The variables are used to establish an optimization problem. A numerical search method is employed to obtain the initial tool setting angle Ф that minimizes the numerical value of the optimization problem, thus obtaining the optimal midpoint E(u). i ); The tooth structure fabrication module is used to prepare the obtained midpoint E(u) i By sequentially connecting the cutting edges, the fitted cutting edge curve E(u) is obtained. On the cylindrical tool body structure, the cutting edge curve is swept along the tool according to the set helical lead to obtain the tool tooth structure.

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