CN-121976029-A - High-precision gear key slot heat treatment deformation control method

CN121976029ACN 121976029 ACN121976029 ACN 121976029ACN-121976029-A

Abstract

The invention relates to a high-precision gear key slot heat treatment deformation control method which comprises the following steps of S100, S200, S300, S400, S500, and S500, wherein the heat treatment is carried out, the heat post detection and feedback optimization is carried out, the heat stress distribution and residual deformation trend of a key slot in each stage of heat treatment is obtained in advance through the heat treatment deformation prediction, the heat post deformation trend is counteracted through applying reverse prestress to side walls, and finally the pretension is carried out according to the adjusted prestress in the actual heat treatment process, so that the two side walls of the key slot are controlled and restrained in the heat shrinkage and phase change expansion process, the deviation of the symmetry degree and the matching dimension drift of the key slot after the heat treatment are obviously reduced, the matching precision and consistency of the gear key slot are improved, the predictive control and the active compensation of the heat treatment deformation are realized, the follow-up grinding allowance and the rework rate are reduced, the product percent of pass and the process stability are improved, and the high engineering practical value is achieved.

Inventors

ZHANG FAN
TIAN RUI
ZHANG HONGLEI
LIU XUELEI
SUN JIAN
ZUO MINGYU
QUAN YU

Assignees

南阳浩帆车辆部件有限公司

Dates

Publication Date: 20260505
Application Date: 20260304

Claims (10)

1. The high-precision gear key slot heat treatment deformation control method is characterized by comprising the following steps of: S100, predicting primary thermal deformation; Collecting material composition, a three-dimensional model and heat treatment process parameters of a workpiece, analyzing thermal stress distribution conditions of each stage through a heat treatment deformation prediction model, and simulating and predicting deformation data of a key slot after heat treatment; s200, designing prestress; According to the thermal post-deformation data of the key slot and the thermal stress distribution conditions of each stage, designing initial prestress, and pre-tightening two side walls with symmetry requirements in the key slot to compensate the thermal stress generated in the thermal treatment process and resist the thermal deformation trend; S300, predicting secondary thermal deformation; the initial prestress is brought into a heat treatment deformation prediction model, deformation data of the key slot after heat is simulated and predicted again, and the initial prestress is adjusted according to a simulation result so as to control the thermal deformation in a designated interval; S400, performing heat treatment; according to the data predicted in the last time, carrying out heat treatment on the workpiece, and applying the adjusted prestress to the two side walls with symmetry requirements in the key slot through a prestress device; s500, post-heat detection and feedback optimization; and detecting the heat-treated workpiece, acquiring post-heat detection data, and feeding back to the heat treatment deformation prediction model.
2. The method for controlling heat treatment deformation of high-precision gear key slot according to claim 1, wherein the heat treatment prediction model predicts the post-heat deviation data by: s110, geometric model mesh division; Establishing a heat treatment simulation geometric model based on a three-dimensional model of the gear, and carrying out finite element mesh division on the geometric model; S120, establishing a temperature field; Calculating the internal temperature field evolution of the workpiece by adopting a heat conduction equation in combination with the material composition of the workpiece and the heat treatment process parameters, and establishing a temperature field model in the heat treatment process for simulating the temperature change of each part of the workpiece in the heat treatment process; s130, thermodynamic coupling calculation; By combining expansion coefficient, phase change characteristic and material mechanical characteristic, analyzing thermal stress caused by temperature field change and influence on the geometry of the workpiece through thermo-mechanical coupling calculation; s140, predicting a thermal deformation result; And predicting the thermal deformation result of the workpiece after heat treatment according to the relation between the temperature field and the geometric deformation of the workpiece.
3. The method for controlling deformation of high-precision gear key slot by heat treatment according to claim 2, wherein in step S200, the initial prestress is designed by the following steps; s210, extracting a thermal deformation amount segment and calculating a target compensation amount; Based on a primary thermal deformation prediction result, extracting deformation model fragments at a plurality of moments according to time steps, and acquiring normal thermal deformation trends of two side walls with symmetry requirements in a key slot at each moment; S220, calculating equivalent tangential stiffness; freezing the temperature field and the phase change state of the deformation model segment, applying normal load increment to two side walls with symmetry requirements in the key slot, obtaining corresponding displacement increment, and calculating equivalent tangential stiffness at the moment according to the ratio of the load increment to the displacement increment; S230, calculating a moment loading value of initial prestress; Determining loading set values of initial prestress at all moments based on the equivalent tangential stiffness and the thermal deformation trend; S240, calculating an initial pre-stress curve; Fitting or smoothing the prestress loading set values at all times to obtain an initial prestress loading curve.
4. The method for controlling deformation of a high-precision gear key groove by heat treatment according to claim 3, wherein in step S300, And taking two side walls with symmetry requirements in the key groove as loading areas, applying an initial pre-stress loading curve as an external load changing along with time to the loading areas, and inputting the initial pre-stress loading curve and the heat treatment process parameters into a heat treatment deformation prediction model together to obtain residual stress distribution and residual deformation prediction results under the condition of applying the initial pre-stress loading curve.
5. The method for controlling deformation of a high-precision gear key slot by heat treatment according to any one of claims 1 to 4, wherein the heat treatment process comprises normalizing, quenching and tempering which are sequentially carried out, and the prestress is only applied to two side walls with symmetry requirements in the key slot in the quenching process.
6. The heat treatment deformation control method for the high-precision gear key slot is characterized in that the prestress device comprises a clamp seat (1), a sliding rod (2) and a pre-tightening seat (3); the clamp seat (1) is used for being arranged on a quenching machine tool, and avoidance holes (101) are formed in the middle of the clamp seat (1); a groove is formed between the inner ring and the outer ring of the gear (5), and a positioning through hole is formed on one side of the groove away from the opening; the clamp seat (1) is provided with a boss (102) matched with the groove, and the boss (102) is provided with a positioning pin (4) matched and spliced with the positioning through hole; The sliding rod (2) is horizontally arranged on the clamp seat (1) in a sliding manner, one end of the sliding rod (2) extends outwards and is fixedly connected with the hydraulic driving device, and the other end of the sliding rod extends into the avoidance hole (101) and is fixedly provided with the pre-tightening seat (3); the pre-tightening seats (3) are distributed in the avoiding holes (101), and the pre-tightening seats (3) are adhered to one side wall of the key groove and exert pre-stress on the side wall along with the outward application of the sliding rod (2).
7. The heat treatment deformation control method for the high-precision gear key slot is characterized in that the clamp seat (1) is divided into a positioning seat (103) and a base (104) which are spliced up and down from the middle part, The lower surface of the positioning seat (103) and the upper surface of the base (104) are correspondingly provided with semicircular sliding grooves so as to splice and form sliding holes (105) matched with the sliding rod (2).
8. The method for controlling the deformation of the key slot of the high-precision gear, as set forth in claim 7, wherein the sliding rod (2), the sliding hole (105) and the positioning seat (103) are symmetrically arranged in left-right direction, and the two side walls with symmetry requirements in the key slot are pre-tightened.
9. The method for controlling the deformation of the key slot of the high-precision gear by heat treatment according to claim 8, wherein the pre-tightening seat (3) is provided with a mounting groove (301) in a region corresponding to the side wall of the key slot, a pre-tightening block (302) is arranged in the mounting groove (301) through a connecting piece (6), and the pre-tightening seat (3) is contacted and attached with the key slot through the pre-tightening block (302).
10. The method for controlling deformation of a high-precision gear key groove by heat treatment according to claim 9, wherein a strain gauge is arranged between the pre-tightening block (302) and the pre-tightening seat (3) so as to detect the installation pre-tightening force of the pre-tightening block (302) and the pre-stress actually applied to the key groove.

Description

High-precision gear key slot heat treatment deformation control method Technical Field The invention relates to the technical field of high-precision gear machining, in particular to a high-precision gear key slot heat treatment deformation control method. Background In the process of the modern high-end equipment manufacturing industry moving towards high precision and high reliability, the high-precision speed reducer is used as a core component of an industrial transmission system, and the performance quality of the high-precision speed reducer directly determines the running stability and reliability of equipment. The symmetry and the matching precision of the gear key slot are used as key structures for transmitting torque, and play a decisive role in the meshing transmission precision of the speed reducer. If the key slot symmetry is insufficient or the matching precision is poor, uneven stress can be caused in the gear meshing process, vibration and noise are generated, the transmission efficiency is reduced, even early failure of the gear is caused, and the development of the high-end equipment manufacturing industry in China is severely restricted. In the traditional gear key slot processing technology, in the process of carrying out heat treatment on a gear, a workpiece is influenced by deformation caused by heat treatment material tissue transformation and stress release, if the heat deformation is lack of control, the symmetry degree and the matching precision of the key slot are difficult to ensure, so that the size deviation of the key slot exceeds +/-0.05 mm, the precision stability is poor, the gear is further enabled to be in non-uniform engagement stress, vibration (amplitude 1.2 mm/s) and noise (75 dB (A)) are generated, the transmission efficiency is reduced (92%), and even early failure is caused. Therefore, when the traditional processing technology is used for processing the gear key slot, particularly in the heat treatment process, the thermal deformation is lack to be controlled, the symmetry and the matching precision of the key slot are difficult to be effectively ensured, the key slot becomes the bottleneck of industry development, and the development of high-end equipment manufacturing industry in China is restricted. Based on this, it is necessary to study a high-precision gear key groove heat treatment deformation control method. Disclosure of Invention In view of the above, the invention aims to provide a high-precision gear key slot heat treatment deformation control method, which can effectively solve the problem that the traditional processing technology of the gear key slot lacks control of the heat deformation and is difficult to ensure the symmetry degree and the matching precision of the key slot. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: the high-precision gear key slot heat treatment deformation control method comprises the following steps: S100, predicting primary thermal deformation; Collecting material composition, a three-dimensional model and heat treatment process parameters of a workpiece, analyzing thermal stress distribution conditions of each stage through a heat treatment deformation prediction model, and simulating and predicting deformation data of a key slot after heat treatment; s200, designing prestress; According to the thermal post-deformation data of the key slot and the thermal stress distribution conditions of each stage, designing initial prestress, and pre-tightening two side walls with symmetry requirements in the key slot to compensate the thermal stress generated in the thermal treatment process and resist the thermal deformation trend; S300, predicting secondary thermal deformation; the initial prestress is brought into a heat treatment deformation prediction model, deformation data of the key slot after heat is simulated and predicted again, and the initial prestress is adjusted according to a simulation result so as to control the thermal deformation in a designated interval; S400, performing heat treatment; according to the data predicted in the last time, carrying out heat treatment on the workpiece, and applying the adjusted prestress to the two side walls with symmetry requirements in the key slot through a prestress device; s500, post-heat detection and feedback optimization; and detecting the heat-treated workpiece, acquiring post-heat detection data, and feeding back to the heat treatment deformation prediction model. Further, the thermal treatment prediction model predicts post-thermal bias data by: s110, geometric model mesh division; Establishing a heat treatment simulation geometric model based on a three-dimensional model of the gear, and carrying out finite element mesh division on the geometric model; S120, establishing a temperature field; Calculating the internal temperature field evolution of the workpiece by adopting a heat conduction equation in combination with