CN-121997490-A - Driving design method for cylindrical turning tooth knife with given relief angle

CN121997490ACN 121997490 ACN121997490 ACN 121997490ACN-121997490-A

Abstract

The invention discloses an active design method of a given relief angle cylindrical turning gear cutter, which belongs to the fields of gear machining and cutter design thereof, and comprises the following steps: setting a machining back angle, a front angle, a cutter tooth number and an initial spiral angle, calculating installation parameters, adjusting the cutter spiral angle, calculating a cutter blade shape by a forming rack, calculating a barrel-shaped envelope surface conjugated with a workpiece gear, checking whether the envelope surface is intersected with a cutter curved surface, and determining the cutter tooth width to obtain the design and installation parameters of the cylindrical turning gear cutter. According to the parameters, the turning machining of the workpiece gear can be realized. The invention aims at the problems that the processing precision of a bowl-loading turning gear cutter is fast along with the attenuation speed of the sharpening situation, and the conventional cylindrical turning gear cutter cannot realize the active design of a processing relief angle, and the designed turning gear cutter has a given design relief angle and has constant processing precision after sharpening.

Inventors

CAO BING
TANG LEYAN
XU KAI
CHEN YONGPENG
LI GUOLONG

Assignees

重庆交通大学

Dates

Publication Date: 20260508
Application Date: 20260108

Claims (9)

1. The method for actively designing the given relief angle cylindrical turning gear knife is characterized by comprising the following steps of: S1, determining a tool relief angle according to gear workpiece parameters and expected machining states Angle of front Tooth number of cutter Initial helix angle of cutter ; S2, establishing a virtual forming rack according to the gear workpiece, and determining the normal modulus of the forming rack Normal pressure angle Helix angle ; S3, according to the given tool relief angle Calculating cone angle between virtual forming rack joint plane and cutter axis And the included angle between the axis of the cutter and the tooth line in the plane of the virtual rack section; S4, calculating the machining back angles of left and right cutting edges of the cutter, adjusting the helix angle of the cutter, and determining the design helix angle of the cutter ; S5, under the condition that the gear workpiece and the cutter are ensured to be accurately meshed with the virtual forming rack, calculating the installation parameters of the cutter in a machine tool coordinate system; s6, calculating an envelope surface and a cutting edge curve of the virtual forming rack in a tool coordinate system according to the installation position relation of the tool relative to the virtual forming rack and the front angle of the tool; S7, establishing a barrel-shaped enveloping surface of the workpiece gear, and determining the tooth width of the cutter Checking whether the envelope surface is intersected with the curved surface of the cutter, and if so, reducing the tooth width of the cutter according to a preset value. And S8, manufacturing a turning cutter on a turning machine tool by using the cutter parameters determined according to the steps to realize turning machining.
2. The method for actively designing a given relief angle cylindrical turning gear cutter according to claim 1, wherein the number of teeth of the cutter in S1 is as follows The selection principle of the tool tooth number and the workpiece tooth number are ensured to be mutually consistent.
3. The method for actively designing a given relief angle cylindrical turning gear cutter according to claim 1, wherein the relief angle of the cutter in S1 is as follows Is the difference between the helix angle of the tooth surface where the left and right cutting edges of the cutter are positioned and the helix angle of the tooth surface where the workpiece gear is correctly meshed.
4. The method for actively designing a given relief angle cylindrical turning gear cutter according to claim 1, wherein the normal modulus of the forming rack is determined in S2 Normal pressure angle Helix angle The calculation formulas of (a) are respectively as follows: in the formula, Representing the pitch radius of the workpiece gear; representing the number of teeth of the workpiece gear; Representing the base radius of the workpiece gear; For the radius of the indexing circle of the workpiece gear, Pitch angle for workpiece gear pitch circle.
5. The method for actively designing a given relief angle cylindrical turning gear cutter according to claim 1, wherein the included angle between the projection of the cutter axis in the S3 and the tooth line on the virtual rack section plane is the initial helix angle of the cutter ; Cone angle of tool axis and virtual rack The following relationship is satisfied: 。
6. the method for actively designing a given relief angle cylindrical turning gear cutter according to claim 1, wherein in S4, the cutter is designed with a helix angle The adjustment principle of (2) is that the back angles of the left cutting edge and the right cutting edge are ensured to be equal, and the calculation formulas are respectively as follows: ; ; tool design helix angle The expression of (2) is as follows: 。
7. The method for actively designing a given relief angle cylindrical turning gear cutter according to claim 1, wherein in S5, the installation parameters of the cutter in a machine tool coordinate system are calculated, and the method comprises the following steps of The intersection point of the cutter axis and the gear axis is positioned relative to the theoretical cutting position in the directions of the X axis, the Y axis and the Z axis 、 And ; The angle of intersection of the cutter axis and the gear axis The plane formed by the axes of the cutter parallel to the Z axis and the Y axis of the machine tool is required to be satisfied, and the calculation formula is as follows: in the formula, Representing the pitch angle of the pitch circle of the workpiece gear; for the rotation angle of the virtual rack around the gear axis, the calculation formula is as follows: According to the installation angle Virtual rack rotation angle Calculating the offset distance of the machining position relative to the intersection point of the gear axis and the cutter axis 、 And The calculation formula is as follows: in the formula, The pitch circle radius of the cutter; For the included angle between the connecting line of the meshing point and the center of the front cutter face of the cutter and the X axis, the calculation formula is as follows: 。
8. the method for actively designing a given relief angle cylindrical turning gear cutter according to claim 7, wherein the pitch radius of the cutter is as follows The expression of (2) is as follows: 。
9. The method for actively designing a given relief angle cylindrical turning gear cutter according to claim 1, wherein in the step S6, the cutting edge of the cutter is a section of an envelope surface and a rake surface of a virtual product-shaped rack in a cutter coordinate system; The envelope surface of the virtual shaped rack may be expressed as follows: in the formula, For virtually forming racks in the tool coordinate system Is provided with an envelope surface; a transformation matrix from the virtual generating rack coordinate system to the tool coordinate system; For virtually forming racks in a virtually forming rack coordinate system The equation in (a); virtual shape-producing rack edge The distance of movement of the shaft, In the tool coordinate system for virtually forming tooth surface of rack Is a normal vector in (a); when the intersection point of the tool pitch circle and the left and right blades is relative to the tool coordinate system In axisymmetry, the normal vector of the rake face may be expressed in the tool coordinate system as Thus, the cutting edge type can be expressed as follows: in the formula, Is the pitch circle of the cutter Intersection of axes.

Description

Driving design method for cylindrical turning tooth knife with given relief angle Technical Field The invention relates to the field of gear machining and cutter design thereof, in particular to an active design method of a given relief angle cylindrical turning gear cutter. Background The gear is an intelligent key machine and universal part with wide range. With the development of new energy automobiles and robots, the demand of the inner gear ring is increased in an explosive manner. The internal tooth processing can not be realized by the hobbing, the difficult problem of low processing efficiency is faced by the slotting process, and the high-precision and high-efficiency processing requirements of the annular gear can not be met. The turning gear processing is a novel process for processing gears, can realize the processing of inner and outer teeth and duplex teeth with shorter tool withdrawal grooves, and has the characteristics of high processing efficiency and high precision. The turning gear is a key for ensuring the turning gear precision, and structural parameters such as a front angle, a rear angle and the like of the cutter are key parameters for influencing the service life and the cutting state of the cutter. The currently commonly adopted turning tooth cutter is a bowl-loading turning tooth cutter. The turning tooth cutter is conical along the axial direction of the cutter. The cutting relief angle is realized by changing the helix angle of the left and right tooth surfaces of the cutter. However, in the actual machining process, the outer diameter of the cutter becomes smaller gradually in the sharpening process along with the abrasion of the cutting edge, so that machining theoretical errors are introduced. The cylindrical turning gear knife is a novel turning gear knife, and the cutting edge type of the turning gear knife is unchanged along the axial direction of the knife. Thus, a constant machining accuracy can be maintained by sharpening multiple times. However, the existing cylindrical turning tool design method is to realize the design of the blade type of the tool by changing the position of the front tool face of the tool on the basis of ensuring the conjugate of the tool and the workpiece, and the rear angle of the tool cannot be ensured although the active design of the front angle of the tool can be realized. Therefore, there is a need for an active design method for a cylindrical turning gear that can achieve a given tool relief angle. Disclosure of Invention Aiming at the defects in the prior art, the invention provides an active design method for a cylindrical turning gear cutter with a given relief angle, wherein the left and right tooth surfaces of the designed turning gear cutter are standard spiral surfaces and have the given relief angle at the same time, and multiple iterations are not needed. The invention achieves the above purpose by the following technical means: S1, determining a tool relief angle according to gear workpiece parameters and expected machining states Angle of frontTooth number of cutterInitial helix angle of cutter; Number of teeth of cutterThe selection principle of the tool tooth number and the workpiece tooth number are ensured to be mutually consistent; tool relief angle Is the difference between the helix angle of the tooth surface where the left and right cutting edges of the cutter are positioned and the helix angle of the tooth surface where the workpiece gear is correctly meshed. S2, establishing a virtual forming rack according to the gear workpiece, and determining the normal modulus of the forming rackNormal pressure angleHelix angle; Based on the workpiece parameters and the cutter parameters of S1, calculating the normal modulus of the virtual forming rackNormal pressure angleHelix angleThe expressions are as follows: in the formula, Representing the pitch radius of the workpiece gear; representing the number of teeth of the workpiece gear; Representing the base radius of the workpiece gear; For the radius of the indexing circle of the workpiece gear, Pitch angle for workpiece gear pitch circle. S3, calculating the cone angle between the axis of the cutter and the virtual rack and the included angle between the axis of the cutter and the tooth line in the plane of the virtual rack section; according to a given working relief angle, i.e. based on the relief angle in S1 And S2, the included angle between the projection of the cutter axis on the virtual rack section plane and the rack tooth line is the initial helix angle of the cutterCone angle of tool axis and virtual rackThe following relationship is satisfied: By this equation solve 。 Further, the pitch circle radius of the cutterCalculated from the following formula: 。 S4, adjusting the helix angle of the cutter and determining the design helix angle of the cutter ; Tool design helix angleThe adjustment principle of (2) is that the clearance angles of the left cutting edge and the