A method for processing and installing a cylindrical gear cutting tool

Abstract

The present invention provides a method for offset processing and installation of a cylindrical gear turning cutter, which determines the process back angle of the cutter, and determines the installation axis intersection angle of the cutter in the machine tool according to the process back angle of the cutter; based on the installation axis intersection angle, determines the angle of rotation of the workpiece around the workpiece rotation axis, that is, the workpiece tool setting angle, determines the position of the meshing point between the cutter pitch circle and the workpiece pitch circle, and determines the angle of rotation of the cutter around the tool rotation axis, that is, the tool setting angle, according to the position of the meshing point between the cutter pitch circle and the workpiece pitch circle; according to the size of the workpiece and the cutter, combined with the cutter installation axis intersection angle, the workpiece tool setting angle and the cutter tool setting angle, determines the offset of the cutter pitch circle center in space relative to the workpiece pitch circle center; installs the cutter according to the installation axis intersection angle, the workpiece tool setting angle, the cutter tool setting angle and the offset of the cutter pitch circle center in space relative to the workpiece pitch circle center. The present invention provides a possibility for avoiding machining interference of a cylindrical gear turning cutter.

Description

Technical Field

[0001] The invention belongs to the technical field of gear cutting processing and installation, and in particular belongs to a method for offset processing and installation of a cylindrical gear cutting tool. Background Art

[0002] As a new gear processing method, powerful gear turning processing combines the continuous development motion mode of gear hobbing and the end face cutting characteristics of gear shaping. It can efficiently complete the processing of internal gear rings, multi-gear shafts with tight space requirements, and gear parts with non-transparent structures. With the rise of new energy vehicles and other industries, it has strong market vitality. In traditional gear turning processing, the tool and the workpiece are in a pair of spatial staggered axis gear meshing relationship. The tool and the gear mesh at the closest point of their spatial axis. The processing and installation method is determined by the installation center distance, the installation axis angle, and the tool axial offset. In this processing and installation method, a conical gear turning cutter is mainly used. The non-zero back angle of the tooth side is used to avoid the interference between the tooth side and the workpiece tooth groove surface. If a cylindrical gear turning cutter is used, it is very easy to cause interference and extrusion between the tooth side and the workpiece machined tooth groove surface, destroying the processing quality of the tooth groove surface. However, with the advancement of rake face grinding, the cutting edge shape of the conical gear turning cutter continues to change, which leads to an increase in the profile error of the workpiece tooth groove processing and a short tool life. In comparison, the cylindrical gear turning cutter can maintain the cutting profile before and after sharpening, and theoretically maintain the processing of blade error, which is of great significance for improving the consistency of workpiece processing accuracy.

[0003] The cylindrical gear turning cutter has a zero-degree back angle structure. In order to ensure that there is no interference between the side surface of the cutter tooth and the tooth groove surface during processing, a certain additional process back angle needs to be set for the cutter. If the method of adding a swing indexing axis is used, the complexity and cost of the machine tool will be greatly increased, and the rigidity of the machine tool will be reduced. Therefore, the tool is adjusted by adjusting the axial offset of the tool to form a certain non-zero process back angle relative to the tooth groove of the workpiece. However, the method based on the axial offset will change the spatial pitch circle relationship between the tool and the workpiece, which is inconsistent with the determination of the spatial pitch circle relationship as the primary principle of tool design and processing installation, resulting in the trial and error of the gear turning processing installation method, complex design process and low efficiency. In addition, the relationship between the relative posture of the tool and the workpiece caused by the axial offset of the tool cannot be directly mapped to the tool setting installation of the gear turning machine, resulting in problems such as unintuitive tool setting and inconvenient operation. Therefore, a gear turning processing installation method that combines active control of the process back angle of the cylindrical gear turning cutter with consistent machine tool processing configuration is very necessary. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the present invention provides a method for offset processing and installation of a cylindrical gear turning cutter to solve the problem of repeated trial and error in the design of non-interference cylindrical gear turning cutters and the inconsistency between the installation parameters of the cylindrical gear turning cutter and the machine tool configuration.

[0005] To achieve the above purpose, the present invention provides the following technical solution: a method for offset processing and installation of a cylindrical gear cutting tool, the specific steps are as follows:

[0006] S1 determines the tool process back angle λ, and determines the installation axis intersection angle Σ of the tool in the machine tool according to the tool process back angle λ;

[0007] S2 determines the workpiece rotation axis z based on the installation axis intersection angle Σ g The angle of rotation, that is, the workpiece tool angle K g , thereby determining the position of the meshing point P between the tool pitch circle and the workpiece pitch circle, and determining the tool rotation axis z around the tool according to the position of the meshing point P between the tool pitch circle and the workpiece pitch circle c，1 The angle of rotation, that is, the tool setting angle K c ;

[0008] S3 is based on the size of the workpiece and tool, combined with the tool installation axis angle Σ and the workpiece tool setting angle K g And tool setting angle K c , determine the tool pitch center O c Relative to the workpiece pitch center O g The offset in space;

[0009] S4 is based on the installation axis intersection angle Σ and the workpiece tool setting angle K g , Tool setting angle K c and tool pitch center O c Relative to the workpiece pitch center O g The tool is mounted with an offset in space.

[0010] Furthermore, in S1, the tool rotation axis z is set c，1 The equivalent installation axis angle Σ is formed by the tangent plane at the meshing point P of the tool pitch circle and the workpiece pitch circle e , according to the tool process back angle λ and the equivalent installation axis angle Σ e Determine the installation axis angle Σ of the tool in the machine tool.

[0011] Furthermore, in S1, the calculation formula of the installation axis angle Σ is:

[0012]

[0013] Furthermore, in S1, the tool process back angle λ ranges from 0 to 90°.

[0014] Furthermore, in S2, the workpiece tool setting angle K g The calculation formula is:

[0015]

[0016] Among them, k io represents the structure of the workpiece, k io =1 indicates external tooth structure, k io =-1 indicates internal tooth structure; Σ e The meshing point P of the workpiece pitch circle and the center O of the workpiece pitch circle g Corresponding to the equivalent installation axis angle in the tangent plane.

[0017] Furthermore, in S3, the tool pitch center O c Relative to the workpiece pitch center O g The offset in space is determined by the center distance E x , eccentricity E y and tool pitch circle center offset E z Indicates that the size of the workpiece is specifically the workpiece pitch radius R g The tool size is specifically the tool pitch radius R c :

[0018] According to the workpiece pitch radius R g , Workpiece tool setting angle K g , Tool pitch radius R c , tool setting angle K c Determine the tool pitch center O c Relative to the workpiece pitch center O g The offset in the x-axis direction, that is, the installation center distance E of the tool x ;

[0019] According to the workpiece pitch radius R g , Workpiece tool setting angle K g , Tool pitch radius R c , tool setting angle K c , the tool installation axis intersection angle Σ determines the tool pitch circle center O c Relative to the workpiece pitch center O g The offset in the y-axis direction, that is, the installation eccentricity E of the tool y ;

[0020] Tool pitch radius R c , tool setting angle K c And the tool installation axis intersection angle Σ determines the tool pitch circle center O c Relative to the workpiece pitch center O g The offset in the z-axis direction, that is, the tool pitch circle center offset E z .

[0021] Furthermore, in S3, the installation center distance of the tool is E x , eccentricity E y and tool pitch circle center offset E z The calculation formula is as follows:

[0022] E x =R g cos(K g )-R c cos(K c )

[0023] E y =R g sin(K g )+R c sin(K c )cos(Σ)

[0024] E z =-|R c sin(K c )sin(Σ)|.

[0025] Further, in S3, the tool pitch circle radius R is calculated according to the tool design parameters. c , tool design parameters include the number of workpiece teeth Z g , Workpiece pitch radius R g , Workpiece pitch helix angle β g 、Number of tool teeth Z c , Tool pitch helix angle β c , specifically:

[0026]

[0027] Furthermore, according to the workpiece tool angle K g The tool setting angle K is determined by the tool installation axis intersection angle Σ and the workpiece structure. c , the calculation formula is:

[0028]

[0029] Among them, k io represents the structure of the workpiece, k io =1 indicates external tooth structure, k io =-1 indicates internal tooth structure; Σ e The meshing point P of the workpiece pitch circle and the center O of the workpiece pitch circle g Corresponding to the equivalent installation axis angle in the tangent plane.

[0030] Furthermore, the equivalent installation shaft angle Σ e Use workpiece pitch helix angle β g , workpiece tooth rotation direction k g , Tool pitch helix angle β c and tooth rotation k c Calculation, specifically:

[0031] Σe =-k g β g -k io k c β c

[0032] Among them, k g and k c Represent the rotation direction of the workpiece and tool respectively, with a value of 1 for right-hand rotation, -1 for left-hand rotation, and 0 for straight teeth; k io represents the structure of the workpiece, k io =1 indicates external tooth structure, k io =-1 indicates an internal tooth structure.

[0033] Compared with the prior art, the present invention has at least the following beneficial effects:

[0034] The present invention provides a method for offsetting the machining and installation of a cylindrical gear turning cutter. The axial intersection angle and the process clearance angle of the gear turning cutter relative to the workpiece can be formed only by offsetting the installation. The process clearance angle provides a possibility for avoiding machining interference of the cylindrical gear turning cutter. Specifically, the process clearance angle of the cutter is used as an active design control variable to make the tool rotation axis z c，1 The installation axis intersection angle Σ is formed relative to the tangent plane at the meshing point P of the tool pitch circle and the workpiece pitch circle. Combined with the design parameters of the workpiece and the tool, the position of the meshing point P of the tool pitch circle and the workpiece pitch circle and the center O of the tool pitch circle can be determined while ensuring that the spatial meshing relationship between the workpiece and the tool remains unchanged. c Relative to the workpiece pitch center O g The offset in space determines the installation parameters of the tool. By installing the tool under the determined installation parameter conditions, the preset tool process back angle can be achieved. The present invention can effectively avoid the reciprocating trial and error process of using the axial elongation of the tool as a variable and then calibrating the tool process back angle in the traditional design method.

[0035] The present invention establishes a relative installation posture relationship between a tool coordinate system and a workpiece coordinate system for tool setting for machine tool installation, so that the installation method is consistent with the motion configuration of a universal gear turning machine, the center distance, eccentricity and tool pitch circle center offset are consistent with the linear motion axis of the universal gear turning machine, and the tool setting angle and the workpiece setting angle are consistent with the tool spindle and the workpiece rotary spindle. It can be seen that the installation method of the present invention can be directly applied to machine tool tool setting.

[0036] The offset processing and installation method of the present invention can support cylindrical gear cutting tools, and can also meet the installation and processing of conical gear cutting tools with zero offset. Therefore, the processing and installation method of the present invention can be used for the development of gear cutting machine CAM system and the design of matching tools. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the installation principle of the gear cutting process of the present invention, wherein FIG a is a top view; FIG b is a front view; and FIG c is a view along the common section of the meshing point P. DETAILED DESCRIPTION

[0038] The present invention is further described below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical solution of this application fall within the protection scope of the present invention.

[0039] For the processing of cylindrical gear cutting tools, the present invention proposes the following Figure 1 The tool is installed in an offset position relative to the workpiece. The workpiece pitch circle and the tool pitch circle touch at point P, which deviates from the tool rotary axis z. c，1 With the workpiece rotation axis z 3，g The shortest center line, that is, x1-O g -z1 plane; at the same time, let the tool rotate along the axis z c，1 The tangent plane at the meshing point P between the tool pitch circle and the workpiece pitch circle forms the installation axis intersection angle Σ and the tool inclination angle. That is, the tool inclination angle is formed while ensuring the tool installation axis intersection angle Σ. The tool inclination angle is the process back angle.

[0040] In this offset processing installation method, referring to the machine tool motion configuration, the tool indexing rotary axis is parallel to the rotary indexing axis of the machine tool coordinate system, and the z axis of the tool coordinate system is c The axis coincides with the tool rotation axis, and the z axis of the workpiece coordinate system g The axis coincides with the workpiece rotation axis, and the origin of the tool and the workpiece are the tool pitch circle center O c and workpiece pitch center O g Based on this, the tool installation axis angle Σ is applied around the x1 axis, which is consistent with the kinematic configuration of the machine tool; the workpiece pitch circle and the tool pitch circle mesh at point P, which is not necessarily located at x1. 1,2 The axis is not on the ground, but there is an offset, that is, the eccentricity E y ; When the eccentricity E y When it is not zero, the common tangent plane between the tool pitch circle and the workpiece pitch circle at point P is not perpendicular to x 1,2,3 The axis is also not parallel to the tool rotation axis vector, but forms a separate process back angle, which makes it possible to avoid machining interference of cylindrical gear turning cutters.

[0041] For this installation method, its design follows the intuitive gear cutting tool process. Starting from the pitch circle of the workpiece and the tool, the tool's process back angle is actively controlled while ensuring that the pitch circle meshing conditions remain unchanged, and then the six core installation parameters are determined, namely the installation axis intersection angle Σ, the tool pitch circle center O c Relative to workpiece pitch center O g Installation center distance E x, eccentricity E y , tool pitch circle center offset E z , tool setting angle K c And the workpiece tool angle K g .

[0042] The invention discloses a cylindrical gear cutting tool offset processing and installation method. The known data in the gear cutting tool design task of the gear workpiece include: the number of teeth, helix angle, hand direction, and tooth profile curve of the gear; the number of teeth of the tool, hand direction of the tool teeth, and helix angle of the tool pitch circle; the preferred tool process back angle λ; the tool parameter to be designed is the tool pitch circle radius R c ; The ultimate goal is to find out the installation parameters of the tool to support the subsequent cutting edge calculation and other links; specifically includes the following steps:

[0043] (1) Determine the tool pitch radius R c :

[0044] According to the input parameters of the gear cutting tool design (number of teeth on the workpiece Z g , workpiece pitch radius R g , workpiece pitch helix angle β g , number of tool teeth Z c , tool pitch helix angle β c ), calculate the tool pitch radius R c as follows:

[0045]

[0046] (2) Determine the equivalent installation axis angle Σ e :

[0047] According to the workpiece pitch helix angle β g , workpiece tooth rotation direction k g , Tool pitch helix angle β c and tooth rotation k c , determine the equivalent installation axis angle Σ of the tool axis projection in the tangent plane at the meshing point P e as follows:

[0048] Σ e =-k g β g -k io k c β c

[0049] Here, k g and k c Respectively represent the rotation direction of the workpiece and the tool, k g =1 means right-hand rotation, k g =-1 means left-hand rotation, k g =0 means straight teeth; k iorepresents the structure of the workpiece, k io =1 indicates external tooth structure, k io =-1 indicates an internal tooth structure.

[0050] (3) Determine the installation axis angle Σ of the tool in the machine tool:

[0051] According to the tool back angle λ and the meshing point P, the equivalent installation axis angle Σ in the tangent plane e Determine the installation axis angle Σ of the tool in the machine tool. The specific calculation formula is as follows:

[0052]

[0053] Preferably, the process back angle control range is 0 to 90°. When the tool process back angle λ is in the range of 0°, the installation method of the present invention can also meet the installation and processing requirements of the tapered gear cutting tool.

[0054] (4) Determine the position of the meshing point P between the workpiece pitch circle and the tool pitch circle:

[0055] According to the installation shaft angle Σ and the equivalent installation shaft angle Σ e The structure of the workpiece determines the workpiece rotation axis z g The rotation angle, that is, the workpiece tool angle K g , after rotation, the coordinate system x3 axis rotates to x g Axis, x g The intersection of the axis and the workpiece pitch circle is the location of the meshing point P between the tool pitch circle and the workpiece pitch circle;

[0056] According to the position of the meshing point P between the tool pitch circle and the workpiece pitch circle, based on the workpiece tool setting angle K g The intersection angle Σ with the tool installation axis and the structure of the workpiece determine the tool rotation axis z c，1 The angle of rotation, that is, the tool setting angle K c , after rotation, the coordinate system axis x 1,2 Rotate to x c axis;

[0057] Workpiece tool setting angle K g And tool setting angle K c The calculation formula is as follows:

[0058]

[0059]

[0060] (5) Determine the tool pitch center O c Relative to the workpiece pitch center O g The eccentric position:

[0061] Based on the workpiece pitch radius Rg , Tool pitch radius R c , tool installation axis angle Σ, workpiece tool setting angle K g And tool setting angle K c , determine the installation center distance E of the tool x , eccentricity E y and tool pitch circle center offset E z , thereby determining the tool pitch center O c Relative to the workpiece pitch center O g The locations are as follows:

[0062] E x =R g cos(K g )-R c cos(K c )

[0063] E y =R g sin(K g )+R c sin(K c )cos(Σ)

[0064] E z =-|R c sin(K c )sin(Σ)|

[0065] In this way, all parameters of the gear cutting process installation are determined, and the cylindrical gear cutting cutter is installed according to the above installation parameters.

[0066] This method has the following corresponding relationship with the configuration of general gear turning machine tools or the configuration of turning-milling composite machining centers: the tool installation axis intersection angle Σ is directly swung out by the rotary indexing axis of the gear turning machine, that is, z in the figure c,1 The axis is perpendicular to the rotary indexing axis of the machine tool; the center of the tool pitch circle is O c Relative to workpiece pitch center O g Installation center distance E x , eccentricity E y and tool pitch circle center offset E z Direct positioning by the linear motion axis of the machine tool; workpiece tool setting angle K g And the tool setting angle K c Directly set by the machine tool's workpiece rotary axis and tool spindle.

[0067] During machining, if the workpiece has no circumferential machining benchmark requirements, it is only necessary to ensure the installation center distance E x , eccentricity E y When the workpiece has circumferential processing benchmark requirements, it is necessary not only to ensure the installation center distance Ex , eccentricity E y The intersection angle Σ with the installation axis must also strictly ensure that the tool setting angle K c , Workpiece tool setting angle K g and tool pitch circle center offset E z . Because the center distance E x , eccentricity E y Determines the spatial configuration relationship between the meshing motion of the tool and the workpiece for the target processing shape, and the tool setting angle K c , Workpiece tool setting angle K g and tool pitch circle center offset E z Determines the position where the tool cuts into the workpiece, that is, the position of the tooth groove in the circumference of the workpiece.

Claims

1. A method for offset machining and installation of a cylindrical gear cutting tool, characterized in that: The specific steps are as follows: S1 determines the tool process back angle λ, and determines the installation axis intersection angle Σ of the tool in the machine tool according to the tool process back angle λ; S2 determines the workpiece rotation axis z based on the installation axis intersection angle Σ g The rotation angle, that is, the workpiece tool angle K g , thereby determining the position of the meshing point P between the tool pitch circle and the workpiece pitch circle, and determining the tool rotation axis z around the tool according to the position of the meshing point P between the tool pitch circle and the workpiece pitch circle c，1 The angle of rotation, that is, the tool setting angle K c ; S3 is based on the size of the workpiece and tool, combined with the tool installation axis angle Σ and the workpiece tool setting angle K g And tool setting angle K c , determine the tool pitch center O c Relative to the workpiece pitch center O g The offset in space; S4 is based on the installation axis intersection angle Σ and the workpiece tool setting angle K g , tool setting angle K c and tool pitch center O c Relative to the workpiece pitch center O g The tool is mounted with an offset in space; In S1, let the tool rotate along the axis z c，1 The equivalent installation axis angle Σ is formed by the tangent plane at the meshing point P of the tool pitch circle and the workpiece pitch circle e , according to the tool process back angle λ and the equivalent installation axis angle Σ e Determine the installation axis intersection angle Σ of the tool in the machine tool; In S1, the calculation formula for the installation axis intersection angle Σ is: In S1, the tool back angle λ ranges from 0 to 90°; In S2, the workpiece tool setting angle K g The calculation formula is: Among them, k io represents the structure of the workpiece, k io =1 indicates external tooth structure, k io =-1 indicates internal tooth structure; Σ e The meshing point P of the workpiece pitch circle and the center O of the workpiece pitch circle g The equivalent installation axis angle in the corresponding tangent plane; In S3, the tool pitch center O c Relative to the workpiece pitch center O g The offset in space is determined by the center distance E x , eccentricity E y and tool pitch circle center offset E z Indicates that the size of the workpiece is specifically the workpiece pitch radius R g The tool size is specifically the tool pitch radius R c : According to the workpiece pitch radius R g , Workpiece tool setting angle K g , Tool pitch radius R c , tool setting angle K c Determine the tool pitch center O c Relative to the workpiece pitch center O g The offset in the x-axis direction, that is, the installation center distance E of the tool x ; According to the workpiece pitch radius R g , Workpiece tool setting angle K g , Tool pitch radius R c , tool setting angle K c , the tool installation axis intersection angle Σ determines the tool pitch circle center O c Relative to the workpiece pitch center O g The offset in the y-axis direction, that is, the installation eccentricity E of the tool y ; Tool pitch radius R c , tool setting angle K c And the tool installation axis intersection angle Σ determines the tool pitch circle center O c Relative to the workpiece pitch center O g The offset in the z-axis direction, that is, the tool pitch circle center offset E z ; In S3, the installation center distance of the tool is E x , eccentricity E y and tool pitch circle center offset E z The calculation formula is as follows: E x =R g cos(K g )-R c cos(K c ) E y =R g sin(K g )+R c sin(K c )cos(Σ) TO z =-|R c sin(K c )sin(∑)|; According to the workpiece tool angle K g The tool setting angle K is determined by the tool installation axis intersection angle Σ and the workpiece structure. c , the calculation formula is: Among them, k io represents the structure of the workpiece, k io =1 indicates external tooth structure, k io =-1 indicates internal tooth structure; Σ e The meshing point P of the workpiece pitch circle and the center O of the workpiece pitch circle g The equivalent installation axis angle in the corresponding tangent plane; The equivalent installation shaft angle Σ e Use workpiece pitch helix angle β g , workpiece tooth rotation direction k g , Tool pitch helix angle β c and tooth rotation k c Calculation, specifically: ∑ e =-k g b g -k io k c b c Among them, k g and k c Represent the rotation direction of the workpiece and tool respectively, with a value of 1 for right-hand rotation, -1 for left-hand rotation, and 0 for straight teeth; k io represents the structure of the workpiece, k io =1 indicates external tooth structure, k io =-1 indicates an internal tooth structure.

2. A cylindrical gear cutting cutter offset processing and installation method according to claim 1, characterized in that: In S3, the tool pitch radius R is calculated based on the tool design parameters. c , tool design parameters include the number of workpiece teeth Z g , Workpiece pitch radius R g , Workpiece pitch helix angle β g 、Number of tool teeth Z c , Tool pitch helix angle β c , specifically:

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