Mechanical seal dynamic pressure groove laser processing process parameter inversion and groove depth processing precision control method
By using a calculation model for the groove depth of the dynamic pressure groove laser processing and a process parameter inversion program, the problem of accurate control of the groove depth of the dynamic pressure groove in mechanical seals was solved, achieving efficient and precise groove depth processing and improving sealing performance and stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- KUNMING UNIV OF SCI & TECH
- Filing Date
- 2023-07-09
- Publication Date
- 2026-08-04
AI Technical Summary
Existing technologies struggle to precisely control the machining accuracy of the hydrodynamic groove in mechanical seals, which affects sealing performance and operational stability. There is also a lack of simple and effective methods for retrieving process parameters.
A dynamic pressure groove laser processing groove depth calculation model was adopted, and a process parameter inversion program was developed. The laser processing parameters were adjusted through multiple inversions until the target groove depth and relative error requirements were met. The groove depth was then processed and measured using a fiber laser marking machine.
Precision machining of the dynamic pressure groove of the mechanical seal has been achieved, with high groove depth accuracy, simple operation process, fewer tests, low cost, high efficiency, and meeting the design control objectives.
Smart Images
Figure CN116652398B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a method for inverting process parameters and controlling the accuracy of groove depth machining in laser processing of dynamic pressure grooves for mechanical seals, belonging to the field of laser precision machining technology for mechanical seals. Background Technology
[0002] As mechanical seal systems evolve towards more complex operating conditions, the requirements for the machining accuracy of the dynamic pressure groove are also increasing. Since the machining accuracy of the dynamic pressure groove depth has a significant impact on sealing performance, accurately controlling the groove depth is of great importance for improving sealing performance and operational stability.
[0003] Currently, laser technology is widely used in the machining of dynamic pressure grooves for mechanical seals, but it can generally only achieve a groove depth accuracy at the micrometer level, and there is still a lack of simple and effective means to precisely control the groove depth. Some researchers, such as Zhang Shan, Mao Wenyuan, and Wang Yan, have conducted research on laser machining of dynamic pressure grooves. Among them, the applicant constructed a simple and effective groove depth calculation model for laser machining of dynamic pressure grooves based on the relationship between groove depth and laser energy density and interaction time. The groove depth calculation results obtained based on the model agree well with experimental results, but it can only be used to predict the groove depth under different process parameters, and cannot obtain a set of process parameters that meet the target groove depth requirements. Furthermore, the applicant previously conducted research on the optimization of laser processing technology for spiral grooves based on the uniform experimental method and the Alternating Conditional Expectations (ACE) method, selecting three sets of process parameters that met the design control objectives. The developed program can predict the groove depth under different process parameters relatively accurately. However, when the actual groove depth does not meet the groove depth processing accuracy requirements, it is necessary to re-predict and perform dynamic pressure groove processing and groove depth measurement until the experimental groove depth meets the groove depth processing accuracy requirements. This operation is somewhat cumbersome and lacks simple and effective measures and methods. Therefore, conducting inversion of process parameters and control of groove depth processing accuracy in laser processing of dynamic pressure grooves for mechanical seals is of significant research importance. Summary of the Invention
[0004] Therefore, the present invention aims to provide a method for inverting process parameters of laser processing of dynamic pressure grooves for mechanical seals and controlling the accuracy of groove depth processing.
[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:
[0006] (1) Based on the processing requirements of the dynamic pressure groove, set the design control target for the dynamic pressure groove: target groove depth h g And the relative error ε of the groove depth;
[0007] (2) Based on the calculation model of groove depth for dynamic pressure groove laser processing, a program for inverting process parameters of dynamic pressure groove laser processing was developed.
[0008] (3) Use the inversion program to perform the first inversion and obtain a set of process parameters that meet the target tank depth requirements;
[0009] (4) Based on the process parameters obtained in the first inversion, the dynamic pressure groove is processed on the end face of the sealing ring using a fiber laser marking machine, and the groove depth is measured using a surface roughness shape measuring machine.
[0010] (5) If the experimental tank depth after the first inversion processing meets the design control target requirements, then the precision machining of the dynamic pressure tank is completed;
[0011] (6) If the experimental tank depth after the first inversion processing does not meet the design control target, then according to the relationship between the experimental tank depth and the target tank depth, select the appropriate inversion method to perform multiple inversion processing until the dynamic pressure tank design control target requirements are met.
[0012] Preferably, the target trench depth in step (1) is 1 to 500 μm, and the relative error of the trench depth is 0 to 5%.
[0013] Preferably, the process parameters are: laser power 1-100W, repetition frequency 1-100kHz, scanning speed 1-10000mm / s, number of markings 1-100 times, and filling spacing 1-100μm.
[0014] Preferably, the shape of the dynamic pressure groove is not limited, and it can be any one of rectangular groove, triangular groove, spiral groove, T-shaped groove, U-shaped groove, herringbone groove, straight groove, and circular arc groove.
[0015] Preferably, the sealing ring material is not limited, including silicon carbide, tungsten carbide, stainless steel, etc.
[0016] Preferably, the experimental tank depth and the target tank depth are related as follows: the experimental tank depth is greater than the target tank depth or the experimental tank depth is less than the target tank depth.
[0017] Preferably, the inversion method is as follows: when the experimental groove depth after the first inversion is less than the target groove depth, the second inversion uses the groove depth error of the first inversion as the target groove depth, and so on for multiple inversion processes; when the experimental groove depth after the first inversion is greater than the target groove depth, the experimental groove depth can be made less than the target groove depth by reducing the number of markings, and then the difference between the target groove depth and the experimental groove depth with reduced markings is used as the target groove depth for the second inversion, and so on for multiple inversion processes.
[0018] Preferably, the calculation model for the depth of the dynamic pressure groove laser processing is as follows:
[0019]
[0020] In the formula, h gTarget groove depth; P is laser power; f is repetition frequency; r0 is focused spot radius; n is the number of markings; τ is pulse width; L mark v is the marking length; scan For scanning speed; P th This represents the ablation power threshold.
[0021] The preferred model for calculating trench depth error is as follows:
[0022] Δh g =h ge -h g
[0023] In the formula, Δh g h represents the groove depth error. ge This refers to the depth of the experimental tank.
[0024] Preferably, the calculation model for the relative error of the trench depth is as follows:
[0025]
[0026] Advantages of this invention: The method for inverting process parameters and controlling the machining accuracy of the groove depth in laser processing of dynamic pressure grooves proposed in this invention is based on the inversion program developed by the groove depth calculation model for laser processing of dynamic pressure grooves. Generally, only one inversion is needed to directly obtain the process parameters that meet the target groove depth and the relative error requirements of the groove depth. If the deviation between the experimental groove depth and the target groove depth is large, the process parameters that meet the target groove depth and the relative error requirements of the groove depth can be obtained through 2 to 3 inversions based on the deviation relationship between the experimental groove depth and the target groove depth. This achieves precision machining of the dynamic pressure groove and has the characteristics of simple operation process, fewer tests, high machining accuracy, low cost, and high efficiency.
[0027] The beneficial effects of this invention are that it can be applied not only to the laser precision machining of dynamic pressure grooves in mechanical seals, but also to the precision machining of microgrooves in other fields, providing theoretical guidance and technical support for the precise control of groove depth in various mechanical seal dynamic pressure grooves or other fields. Attached Figure Description
[0028] Figure 1 This is a flowchart of the present invention;
[0029] Figure 2 The image shows the two-dimensional morphology of the groove depth after the first inversion processing at a target groove depth of 5 μm.
[0030] Figure 3 Two-dimensional topographic images of the groove depth after two inversion processes at a target groove depth of 5μm;
[0031] Figure 4 The image shows the two-dimensional morphology of the trench after the first inversion processing at a target trench depth of 20 μm.
[0032] Figure 5 Two-dimensional topographic images of the groove depth after two inversion processes at a target groove depth of 20 μm. Detailed Implementation
[0033] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.
[0034] Example 1: A method for inverting process parameters and controlling the machining accuracy of groove depth in laser processing of dynamic pressure grooves for mechanical seals, comprising the following steps:
[0035] (1) Based on the processing requirements of the dynamic pressure groove, set the design control target for the dynamic pressure groove: target groove depth h g And the relative error ε of the groove depth;
[0036] (2) Based on the calculation model of groove depth for dynamic pressure groove laser processing, a program for inverting process parameters of dynamic pressure groove laser processing was developed.
[0037] (3) Use the inversion program to perform the first inversion and obtain a set of process parameters that meet the target tank depth requirements;
[0038] (4) Based on the process parameters obtained in the first inversion, the dynamic pressure groove is processed on the end face of the sealing ring using a fiber laser marking machine, and the groove depth is measured using a surface roughness shape measuring machine.
[0039] (5) If the experimental tank depth after the first inversion processing meets the design control target requirements, then the precision machining of the dynamic pressure tank is completed;
[0040] (6) If the experimental tank depth after the first inversion processing does not meet the design control target, then according to the relationship between the experimental tank depth and the target tank depth, select the appropriate inversion method to perform multiple inversion processing until the dynamic pressure tank design control target requirements are met.
[0041] Example 2: The dynamic pressure groove is machined into a 3×3mm square shape. The design control target is: target groove depth h. g =5μm, relative error of tank depth ε =5%. Based on the developed process parameter inversion program, the first inversion was performed, obtaining a set of process parameters that meet the design control objectives: P = 9.61W, f = 60kHz, v scan = 609.44 mm·s -1 S = 17.3606 μm, n = 3, and the dynamic pressure groove was processed and the groove depth was measured using this set of process parameters. The measured groove depth was only 4.15 μm, that is, the experimental groove depth after the first inversion processing differed from the target groove depth by 0.85 μm, and the relative error of the groove depth was 17.00%. Therefore, multiple inversion processing is required to meet the design control target requirements.
[0042] The target groove depth for the second inversion was set to 0.85 μm, and the number of calibrations was set to 1 to improve the processing efficiency of the dynamic pressure groove. The second inversion was performed using the developed process parameter inversion program, yielding a set of process parameters that met the target groove depth requirements: P = 3.87 W, f = 35 kHz, v scan = 707.14 mm·s -1 S = 6.0433 μm, n = 1. Using the process parameters obtained from the first and second inversions, the same area of the sealing ring was processed sequentially. The groove depth after the two inversions was measured to be 4.9 μm, meaning the groove depth after the second inversion was 0.75 μm, with a relative error of 11.76%. The relative error of the groove depth after two inversions was 2%. These results indicate that although the relative error of the groove depth after the second inversion exceeded 10%, the groove depth processing error of the dynamic pressure groove can still be controlled within 5% through two inversions, meeting the design control target requirements of the dynamic pressure groove.
[0043] Figure 2 This is a two-dimensional topographic image of the groove depth after the first inversion processing at a target groove depth of 5 μm. Figure 3 The figures show the two-dimensional topography of the groove depth after two inversion processes at a target groove depth of 5 μm. As can be seen from the figures, the experimental groove depth after the first inversion process deviates significantly from the target groove depth. However, through two inversion processes, the groove depth is ultimately controlled to approximately 5 μm, with the relative error of the groove depth controlled within 5%. This demonstrates the feasibility of the proposed method for inverting process parameters and controlling the groove depth machining accuracy in laser processing of dynamic pressure grooves for mechanical seals.
[0044] Example 3: The dynamic pressure groove is machined into a 3×3mm square shape. The design control target is: target groove depth h. g =20μm, tank depth error ε=5%. Based on the developed process parameter inversion program, the first inversion was performed, obtaining a set of process parameters that meet the design control objectives: P=17.11W, f=40kHz, v scan = 495.16 mm·s -1 S = 16.0909 μm, n = 3, and the dynamic pressure groove was processed and the groove depth was measured using this set of process parameters. The measured groove depth was 21.11 μm, that is, the experimental groove depth after the first inversion processing was 1.11 μm higher than the target groove depth, and the relative error of the groove depth was 5.55%.
[0045] To control the relative error of the groove depth within 5%, the number of calibrations was reduced by one, while keeping other process parameters unchanged. The actual groove depth after two calibrations was 14.06 μm, which differed from the target groove depth by 5.94 μm. The target groove depth for the second inversion was set to 5.94 μm, and the number of calibrations was again set to one. Using the developed process parameter inversion program, the second inversion was performed, obtaining a set of process parameters that met the target groove depth requirements: P = 9.61 W, f = 50 kHz, v scan = 239.34 mm·s -1 S = 14.7195 μm, n = 1. The same area of the sealing ring was processed sequentially using the process parameters obtained from the first and second inversions. The groove depth after the two inversions was measured to be 20.10 μm, that is, the groove depth after the second inversion was 6.04 μm, and the relative error of the groove depth was 1.68%. The relative error of the groove depth after the two inversions was 0.5%, which meets the design control target requirements of the dynamic pressure groove.
[0046] Figure 4 This is a two-dimensional topographic image of the groove depth after the first inversion processing at a target groove depth of 20 μm. Figure 5 The figures show the two-dimensional morphology of the groove depth after two inversion processes at a target groove depth of 20 μm. As can be seen from the figures, the experimental groove depth after the first inversion process still deviates somewhat from the target groove depth. However, through two inversion processes, the groove depth is ultimately controlled to approximately 20 μm, with the relative error of the groove depth controlled within 5%. This demonstrates the feasibility of the proposed method for inverting process parameters and controlling the groove depth machining accuracy in laser processing of dynamic pressure grooves for mechanical seals.
[0047] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of the invention and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of the invention should be included within the protection scope of the invention. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.
Claims
1. A mechanical seal dynamic pressure groove laser processing process parameter inversion and groove depth processing precision control method, characterized in that, The method includes the following steps: (1) According to the dynamic pressure groove processing requirements, set the dynamic pressure groove design control target: target groove depth h g and groove depth relative error ε ; (2) Based on the calculation model of groove depth for dynamic pressure groove laser processing, develop a program for inverting process parameters of dynamic pressure groove laser processing; (3) Use the inversion program to perform the first inversion and obtain a set of process parameters that meet the target tank depth requirements; (4) Based on the process parameters obtained in the first inversion, the dynamic pressure groove is processed on the end face of the sealing ring using a fiber laser marking machine, and the groove depth is measured using a surface roughness shape measuring machine. (5) If the experimental tank depth after the first inversion processing meets the design control target requirements, then the precision machining of the dynamic pressure tank is completed; (6) If the experimental tank depth after the first inversion processing does not meet the design control target, then according to the relationship between the experimental tank depth and the target tank depth, select the appropriate inversion method to perform multiple inversion processing until the dynamic pressure tank design control target requirements are met. The inversion method is as follows: when the experimental groove depth after the first inversion is less than the target groove depth, the second inversion uses the groove depth error of the first inversion as the target groove depth, and so on for multiple inversion processes; when the experimental groove depth after the first inversion is greater than the target groove depth, the experimental groove depth can be made less than the target groove depth by reducing the number of markings, and then the difference between the target groove depth and the experimental groove depth with reduced markings is used as the target groove depth for the second inversion, and so on for multiple inversion processes.
2. The mechanical seal dynamic pressure groove laser processing process parameter inversion and groove depth processing precision control method according to claim 1, characterized in that: the target groove depth h g is 1-500 µm, the relative error of groove depth ε is 0-5%.
3. The mechanical seal dynamic pressure groove laser processing process parameter inversion and groove depth processing precision control method according to claim 1, characterized in that: The process parameters are: laser power 1~100W, repetition frequency 1~100kHz, scanning speed 1~10000mm / s, number of markings 1~100 times, and filling spacing 1~100μm.
4. The mechanical seal dynamic pressure groove laser processing process parameter inversion and groove depth processing precision control method according to claim 1, characterized in that: The shape of the dynamic pressure groove is not limited, and can be any one of the following: rectangular groove, triangular groove, spiral groove, T-shaped groove, U-shaped groove, herringbone groove, straight groove, and circular arc groove.
5. The mechanical seal dynamic pressure groove laser processing process parameter inversion and groove depth processing precision control method according to claim 1, characterized in that: The sealing ring material is not limited, including silicon carbide, tungsten carbide or stainless steel.
6. The mechanical seal dynamic pressure groove laser processing process parameter inversion and groove depth processing precision control method according to claim 1, characterized in that: The experimental tank depth and the target tank depth are related in that the experimental tank depth is greater than the target tank depth or the experimental tank depth is less than the target tank depth.
7. The method for inverting process parameters and controlling groove depth machining accuracy in laser processing of dynamic pressure grooves for mechanical seals according to claim 1, characterized in that: The trench depth error calculation model is as follows: 。 8. The mechanical seal dynamic pressure groove laser processing process parameter inversion and groove depth processing precision control method according to claim 1, characterized in that: The calculation model for the relative error of the trench depth is as follows: 。 9. The mechanical seal dynamic pressure groove laser processing process parameter inversion and groove depth processing precision control method according to claim 1, characterized in that: The calculation model for the depth of the laser processing groove in the dynamic pressure groove of the mechanical seal is as follows: 。