A damping oil precision filling method based on vacuum environment control

Abstract

The present application relates to damping oil filling technical field, disclose a kind of based on vacuum environment control's damping oil precision filling method, comprising the following steps: step 1, establish the datum absolute pressure of oil cavity and workpiece cavity and set process temperature;Step 2, detect the absolute pressure of two cavities and in the same pressure state with small opening degree to open communication valve and carry out pre-wetting;Step 3, calculate the first pressure difference and set two cavity pressure difference;Step 4, obtain real-time correction quality forms filling process data;Step 5, according to filling process data adjustment first pressure difference, in real-time correction quality reaches target proportion when trigger end pressure relief;Step 6, determine filling termination time, determine final filling quality after pressure maintaining;Step 7, execute sealing and sealing detection, and based on process parameter and filling data generation fixed setting parameter table.The present application realizes the stable propulsion of damping oil filling process, accurate determination of end point and high-precision control of final filling quality.

Description

Technical Field

[0001] This invention belongs to the field of damping oil filling technology, specifically relating to a precision filling method for damping oil based on vacuum environment control. Background Technology

[0002] Damping oil is widely used in precision machinery, instruments, and consumer electronics to achieve smooth damping control, structural buffering, and motion stability. As product structures evolve towards miniaturization, lightweighting, and high consistency, the requirements for the accuracy and repeatability of damping oil filling have significantly increased, especially in small cavities or narrow flow channels where the filling volume is minimal and the allowable deviation is extremely low, placing higher demands on process control. Conventional damping oil filling methods are mostly based on atmospheric pressure environments, relying on flow control valves or pressure-driven mechanisms for propulsion. However, atmospheric pressure environments are susceptible to the effects of gas compressibility, interface discontinuities, pressure fluctuations, and weighing system response lags. This leads to instability in the initial filling stage, difficulty in accurately matching the flow rate to the target, and significant noise interference in endpoint judgment. Furthermore, even after sealing, micro-leakage or residual pressure can still cause quality deviations.

[0003] To address these issues, the industry has gradually introduced vacuum-assisted filling methods, which reduce gas entrainment by lowering ambient pressure. However, existing technologies often only perform vacuuming before filling, failing to establish a complete vacuum environment pressure control chain throughout the filling process. This makes it difficult to achieve consistent control across multiple stages, including pressure source, flow response, interface status, and weighing calibration. Furthermore, existing filling methods generally lack closed-loop adjustment mechanisms based on real-time mass or mass flow rate, making it impossible to dynamically correct the pressure drive quantity according to the actual flow conditions during filling. In terms of filling endpoint determination and subsequent sealing detection, they largely rely on single-point data or empirical thresholds, resulting in limited stability and difficulty in meeting the demands of high-consistency mass production. Summary of the Invention

[0004] This invention provides a precision filling method for damping oil based on vacuum environment control, which solves the technical problems in related technologies, such as difficulty in maintaining stability during the damping oil filling process, easy misjudgment of the filling endpoint, and impact on batch consistency caused by interface discontinuity, flow rate regulation lag, and residual pressure interference.

[0005] This invention provides a method for precise filling of damping oil based on vacuum environment control, comprising the following steps:

[0006] Step 1: Establish a reference absolute pressure environment and set the process temperature in the oil chamber and workpiece chamber, obtain the zero point value of the platform scale, and set the process parameters.

[0007] Step 2: Under the reference absolute pressure environment, detect the absolute pressure of the oil chamber and the absolute pressure of the workpiece chamber. When it is determined that the oil chamber and the workpiece chamber are under the same pressure, control the connecting valve to open for pre-wetting.

[0008] Step 3: Determine the first pressure difference based on the process parameters, the equivalent radius of the channel, and the channel length, and set the pressure difference between the oil chamber and the workpiece chamber based on the reference absolute pressure;

[0009] Step 4: Under the first differential pressure, open the connecting valve to push the damping oil into the workpiece cavity. Obtain the real-time correction mass based on the zero point value of the platform scale according to the preset sampling cycle, and form the filling process data, which includes the real-time correction mass and the real-time mass flow rate.

[0010] Step 5: Adjust the first differential pressure according to the target volume flow rate in the filling process data and process parameters. When the real-time correction quality reaches the preset ratio of the target filling quality, trigger the end depressurization process.

[0011] Step 6: During the final depressurization process, determine the injection termination time based on the injection process data, close the connecting valve, and maintain the reference absolute pressure of the oil chamber and the workpiece chamber during the pressure holding time. Determine the final injection quality based on the real-time correction quality at the end of the pressure holding time.

[0012] Step 7: Perform sealing and sealing tests on the workpiece, and generate a fixed setting parameter table based on process parameters, filling process data, and final filling quality.

[0013] Furthermore, the process parameters include oil viscosity, oil density, target volumetric flow rate, and target filling mass.

[0014] Furthermore, the absolute pressure of the oil chamber and the absolute pressure of the workpiece chamber are detected, and when it is determined that the oil chamber and the workpiece chamber are under the same pressure, the connecting valve is opened for pre-wetting, including:

[0015] Step 11: Collect the absolute pressure of the oil chamber and the absolute pressure of the workpiece chamber respectively, and determine that the oil chamber and the workpiece chamber are under the same pressure when the difference between the two does not exceed the preset pressure difference threshold.

[0016] Step 12: When the oil chamber and the workpiece chamber are under the same pressure, control the connecting valve to open at a preset small opening, and maintain the preset small opening during the pre-wetting time.

[0017] Step 13: After the pre-wetting time is over, close the connecting valve and use the liquid distribution state generated at the inlet of the workpiece cavity as the continuous oil film interface.

[0018] Further, a first pressure difference is determined, and the pressure difference between the oil chamber and the workpiece chamber is set based on the reference absolute pressure, including:

[0019] Step 21: Extract the oil viscosity and target volumetric flow rate from the process parameters, and extract the channel equivalent radius and channel length from the channel structure. Calculate the first pressure difference based on the Poiseuille laminar flow model.

[0020] Step 22: Under the condition that the absolute pressure of the workpiece cavity is kept at the reference absolute pressure, the absolute pressure of the oil cavity is set to the sum of the reference absolute pressure and the first pressure difference, and the absolute pressure of the oil cavity is monitored with a fixed sampling period, so that the difference between the maximum and minimum values ​​of the absolute pressure of the oil cavity collected in N consecutive samples does not exceed the preset stable threshold.

[0021] Step 23: Calculate the difference between the absolute pressure of the oil chamber and the absolute pressure of the workpiece chamber using data collected N times consecutively as the actual pressure difference. When the actual pressure difference does not exceed the preset steady-state threshold of pressure difference, it is determined that the first pressure difference is in a steady state.

[0022] Furthermore, real-time calibration quality is acquired, and filling process data is generated, including:

[0023] Step 31: After the first differential pressure reaches a steady state, control the connecting valve to switch from the closed state to the open state, and start the sampling timer corresponding to the preset sampling period to execute a unified time reference;

[0024] Step 32: Read the mass measurement value from the platform scale at each sampling time, calculate the real-time corrected mass at that sampling time based on the zero point value of the platform scale, record the real-time corrected mass and the time label of the corresponding sampling time as a real-time corrected mass sequence arranged in time order, and continuously detect the real-time corrected mass sequence according to the sampling period, and remove abnormal jump values.

[0025] Step 33: The real-time quality flow rate is obtained by normalizing the difference in real-time correction quality between adjacent sampling times in the real-time correction quality sequence according to a preset sampling period. The real-time quality flow rate is then combined with the real-time correction quality at the corresponding sampling time to generate the refueling process data arranged in chronological order.

[0026] Further, the first differential pressure is adjusted, and when the real-time correction mass reaches a preset ratio of the target injection mass, the end-of-line depressurization process is triggered, including:

[0027] Step 41: Obtain the real-time mass flow rate, convert the real-time mass flow rate and the target volumetric flow rate in the process parameters into the target mass flow rate according to the density relationship, generate the mass flow rate deviation based on the difference between the two, and calculate the first differential pressure adjustment amount based on the product of the mass flow rate deviation and the preset adjustment coefficient.

[0028] Step 42: The first differential pressure adjustment amount is superimposed with the current first differential pressure to obtain the updated first differential pressure, and an updated first differential pressure sequence is generated with the sampling time as the index;

[0029] Step 43: During the process of updating the first differential pressure sequence, the real-time correction mass is read from the filling process data, and the ratio of the real-time correction mass to the target filling mass in the process parameters is calculated. When the ratio reaches the preset ratio, an end-of-line depressurization trigger signal is generated to trigger the end-of-line depressurization process.

[0030] Furthermore, a preset adjustment step size upper limit is set for the first differential pressure adjustment amount, and the portion exceeding the preset adjustment step size upper limit is truncated during the adjustment process.

[0031] Furthermore, the refueling termination time is determined, and the final refueling quality is determined based on the real-time correction quality, including:

[0032] Step 51: Obtain the real-time quality flow rate. When the real-time quality flow rate is not higher than the preset flow termination threshold in M ​​consecutive samplings, the Mth sampling time is taken as the refueling termination time, and the connecting valve is switched from the open state to the closed state at the refueling termination time.

[0033] Step 52: After the connecting valve is closed, the absolute pressure of the oil chamber and the absolute pressure of the workpiece chamber are set as the reference absolute pressure. During the pressure holding time, the absolute pressure of the oil chamber and the absolute pressure of the workpiece chamber are collected according to the preset sampling period. It is determined that the continuous sampling values ​​are all within the preset pressure stability threshold of the reference absolute pressure.

[0034] Step 53: At the end of the pressure holding time, read the real-time correction mass corresponding to the end of the pressure holding time from the filling process data, determine the real-time correction mass as the final filling mass, and use the final filling mass as the end value of the filling process.

[0035] Furthermore, the workpiece is sealed and tested for sealing, and a fixed parameter table is generated based on process parameters, filling process data, and final filling quality, including:

[0036] Step 61: Perform a sealing operation on the workpiece, record the sealing action data, and collect the absolute pressure of the workpiece cavity according to the preset sampling period. The Pth sampling time when the consecutive P sampling values ​​are all within the sealing detection threshold is taken as the sealing detection completion time, and sealing detection data is formed.

[0037] Step 62: At the moment when the seal test is completed, integrate the process temperature, target volume flow rate and target filling mass in the process parameters with the real-time mass flow rate sequence and real-time correction mass sequence in the filling process data, as well as the final filling mass, to form a filling record dataset.

[0038] Step 63: Construct the field structure of the fixed setting parameter table based on the filling record dataset and sealing test data, and write the corresponding data content according to the field to generate the fixed setting parameter table for the corresponding batch.

[0039] Furthermore, during the sealing test, a first sealing test threshold and a second sealing test threshold are set respectively. The absolute pressure of the workpiece cavity is continuously collected according to a preset sampling period. When the Q consecutive sampling values ​​are all within the preset range corresponding to the first sealing test threshold, the Qth sampling time is determined as the sealing stability judgment time. The difference between the maximum and minimum sampling values ​​within the preset sliding sampling window is calculated as the fluctuation amplitude. When the fluctuation amplitude does not exceed the second sealing test threshold, the fluctuation requirement is determined to be met. When the sampling interval where the sealing stability judgment time is located completely overlaps with the sliding sampling window corresponding to the fluctuation amplitude and both judgment conditions are met, the sealing test is determined to be qualified.

[0040] The beneficial effects of this invention are as follows: By establishing a stable vacuum environment pressure baseline throughout the entire filling process, this invention ensures that the oil chamber and workpiece chamber are under controllable pressure conditions before, during, and after filling, effectively avoiding initial flow instability caused by gas entrainment, interface abrupt changes, and environmental fluctuations under normal pressure conditions. Through the calculation of the first pressure difference based on the Poiseuille laminar flow model, combined with the acquisition and correction of real-time mass and mass flow rates, precise driving and dynamic closed-loop regulation of the filling process are achieved, ensuring that the filling flow rate continuously matches the process target. Pre-wetting establishes a continuous oil film interface, further reducing transient deviations in the initial filling stage; end-of-line pressure relief, flow termination determination, and pressure stabilization confirmation ensure accurate and reliable final filling quality. The seal detection introduces a dual-threshold and sliding window mechanism, enabling a comprehensive judgment of the stability and volatility of the seal state under vacuum conditions. Overall, this invention improves the accuracy, consistency, and repeatability of damping oil filling. Attached Figure Description

[0041] Figure 1 This is a flowchart of a precision damping oil filling method based on vacuum environment control according to the present invention. Detailed Implementation

[0042] The subject matter described herein will now be discussed with reference to exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and implement the subject matter described herein, and changes may be made to the function and arrangement of the elements discussed without departing from the scope of this specification. Various processes or components may be omitted, substituted, or added as needed in the examples. Furthermore, features described in some examples may be combined in other examples.

[0043] It should be noted that, unless otherwise defined, the technical or scientific terms used in one or more embodiments of the present invention should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in one or more embodiments of the present invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0044] like Figure 1 As shown, a method for precise filling of damping oil based on vacuum environment control includes the following steps:

[0045] Step 1: Establish a reference absolute pressure environment and set the process temperature in the oil chamber and workpiece chamber, obtain the zero point value of the platform scale, and set the process parameters.

[0046] Step 2: Under the reference absolute pressure environment, detect the absolute pressure of the oil chamber and the absolute pressure of the workpiece chamber. When it is determined that the oil chamber and the workpiece chamber are under the same pressure, control the connecting valve to open for pre-wetting.

[0047] Step 3: Determine the first pressure difference based on the process parameters, the equivalent radius of the channel, and the channel length, and set the pressure difference between the oil chamber and the workpiece chamber based on the reference absolute pressure;

[0048] Step 4: Under the first differential pressure, open the connecting valve to push the damping oil into the workpiece cavity. Obtain the real-time correction mass based on the zero point value of the platform scale according to the preset sampling cycle, and form the filling process data, which includes the real-time correction mass and the real-time mass flow rate.

[0049] Step 5: Adjust the first differential pressure according to the target volume flow rate in the filling process data and process parameters. When the real-time correction quality reaches the preset ratio of the target filling quality, trigger the end depressurization process.

[0050] Step 6: During the final depressurization process, determine the injection termination time based on the injection process data, close the connecting valve, and maintain the reference absolute pressure of the oil chamber and the workpiece chamber during the pressure holding time. Determine the final injection quality based on the real-time correction quality at the end of the pressure holding time.

[0051] Step 7: Perform sealing and sealing tests on the workpiece, and generate a fixed setting parameter table based on process parameters, filling process data, and final filling quality.

[0052] In one embodiment of the invention, a reference absolute pressure environment is first established in the oil chamber and the workpiece chamber. The reference absolute pressure refers to the state where the oil chamber and the workpiece chamber are jointly evacuated to a preset stable absolute pressure under the action of a vacuum system. This absolute pressure serves as a unified pressure baseline for subsequent filling processes, preventing environmental pressure fluctuations from affecting the flow state of the damping oil and the quality measurement process. Simultaneously with establishing the reference absolute pressure, a temperature control device maintains the system at a set process temperature. The process temperature ensures that the oil viscosity remains stable within a controllable range, keeping the flow resistance caused by viscosity consistent, thereby avoiding flow disturbances caused by temperature drift.

[0053] After the reference absolute pressure and process temperature have stabilized, a zero-point calibration operation is performed on the platform scale to obtain the zero-point value. The zero-point value is used to eliminate the initial offset of the platform scale caused by factors such as changes in cavity pressure, thermal drift of the platform, or changes in mechanical support force in a vacuum environment, so that subsequent mass measurements based on the platform scale can reflect the actual mass of the oil entering the workpiece cavity.

[0054] The process parameters required for this invention are set, including oil viscosity, oil density, target volumetric flow rate, and target filling mass. Oil viscosity characterizes the flow resistance of the oil within the channel; oil density is used to convert the mass measurement result to the volumetric flow rate; the target volumetric flow rate defines the expected oil propulsion speed during filling; and the target filling mass determines the filling termination condition.

[0055] In one embodiment of the present invention, detecting the absolute pressure of the oil chamber and the absolute pressure of the workpiece chamber, and determining that the oil chamber and the workpiece chamber are under the same pressure, controls the opening of the connecting valve for pre-wetting, including:

[0056] Step 11: The absolute pressure of the oil chamber and the absolute pressure of the workpiece chamber are collected by the pressure sensor at a preset sampling period. When the difference between the two does not exceed the preset pressure difference threshold, it is determined that the oil chamber and the workpiece chamber are under the same pressure. The absolute pressure of the oil chamber and the absolute pressure of the workpiece chamber represent the current absolute pressure values ​​of the two chambers in a vacuum environment. The preset pressure difference threshold is used to limit the maximum allowable pressure difference range between the two chambers to avoid the oil from becoming unstable due to sudden pressure difference when the connecting valve is opened later.

[0057] Step 12: When the oil chamber and the workpiece chamber are under the same pressure, the control valve is opened to a preset small opening, so that the oil enters the inlet area of ​​the workpiece chamber with a very low propulsion amount, and the preset small opening is maintained during the pre-wetting time. The pre-wetting time refers to the time period during which the oil is kept in slow contact with the inlet of the workpiece chamber under the small opening state, which is used to ensure that the oil is fully spread in the vacuum environment and forms a continuous liquid covering layer.

[0058] Step 13: After the pre-wetting time is completed, close the connecting valve and use the liquid distribution state generated at the inlet of the workpiece cavity as the continuous oil film interface. The continuous oil film interface refers to the uniform and uninterrupted liquid coating layer formed by the oil on the solid surface under vacuum. This coating layer can provide a stable starting interface for the subsequent high-flow-rate filling stage, avoiding gas entrainment, interface rupture, or transient unstable flow in the early stage of filling.

[0059] Through the above steps, this embodiment enables the oil chamber and the workpiece chamber to reach the same pressure in a vacuum environment, and then forms a continuous oil film interface in a controlled manner, providing stable flow initiation conditions for the subsequent damping oil filling process. This method can significantly improve the controllability of the filling process and reduce flow disturbances caused by interface discontinuities in the initial stage, making the precision filling of damping oil more stable, repeatable, and highly consistent.

[0060] In one embodiment of the present invention, determining a first pressure difference and setting the pressure difference between the oil chamber and the workpiece chamber based on a reference absolute pressure includes:

[0061] Step 21: Extract the oil viscosity and target volumetric flow rate from the process parameters, and extract the channel equivalent radius and channel length from the channel structure. Calculate the first pressure difference based on the Poiseuille laminar flow model. The channel equivalent radius represents the overall dimensional characteristics of the channel, and the channel length and channel equivalent radius together determine the flow resistance characteristics of the oil within the channel. The Poiseuille laminar flow model can analytically describe the relationship between fluid flow rate and pressure difference under laminar flow conditions, and therefore can be used to obtain the pressure difference driving quantity that matches the target volumetric flow rate, i.e., the first pressure difference.

[0062] Step 22: While maintaining the absolute pressure of the workpiece cavity at the reference absolute pressure, set the absolute pressure of the oil cavity to the sum of the reference absolute pressure and the first pressure difference, and monitor the absolute pressure of the oil cavity at a fixed sampling period, so that the difference between the maximum and minimum values ​​of the absolute pressure of the oil cavity collected in N consecutive samples does not exceed the preset stable threshold; where N is an integer from 3 to 10, preferably set to 5. This step is used to ensure that the pressure regulation action has reached a stable state in the vacuum environment and will not affect the subsequent filling process due to pressure fluctuations.

[0063] Step 23: Calculate the difference between the absolute pressure in the oil chamber and the absolute pressure in the workpiece chamber using N consecutive data acquisitions. If this actual pressure difference does not exceed a preset steady-state pressure difference threshold, the first pressure difference is determined to be in a steady state. The preset steady-state pressure difference threshold is used to limit the allowable pressure difference deviation range between the oil chamber and the workpiece chamber, thereby ensuring that the first pressure difference has formed a pressure difference condition suitable for stabilizing the propulsion damping oil under vacuum conditions. It should be noted that step 22 is only used to determine that the oil chamber pressure is stable, while step 23 is used to determine that the pressure difference is stable.

[0064] Through the above steps, this embodiment accurately establishes the first pressure difference based on the fluid laminar flow theory in a vacuum environment, and ensures that the pressure driving conditions are stable and reliable through a two-stage steady-state judgment mechanism. This provides a clear, stable and repeatable pressure driving force for the subsequent damping oil filling process, avoiding pressure disturbances and flow instability problems that are prone to occur in normal pressure environments, thereby improving the stability and consistency of precise damping oil filling.

[0065] In one embodiment of the present invention, acquiring real-time calibration quality and forming filling process data includes:

[0066] Step 31: After the first differential pressure reaches a steady state, control the connecting valve to switch from the closed state to the open state, and start the sampling timer corresponding to the preset sampling period so that all subsequent sampling moments are recorded with a unified time reference. This unified time reference avoids measurement deviations caused by time drift or asynchronous sampling.

[0067] Step 32: At each sampling moment, the mass measurement value is read from the platform scale. The real-time corrected mass at that sampling moment is calculated based on the zero-point value of the platform scale. The zero-point value of the platform scale is used to eliminate the initial offset of the platform scale caused by changes in external force or cavity pressure under vacuum conditions, so that the real-time corrected mass can accurately reflect the mass of the oil entering the workpiece cavity. The real-time corrected mass and the corresponding sampling moment timestamp are recorded as a real-time corrected mass sequence arranged in chronological order. The real-time corrected mass sequence is continuously detected according to the sampling period to identify and eliminate abnormal jump values ​​caused by mechanical vibration, sensor transient noise, or environmental interference, thereby ensuring the validity and stability of the data.

[0068] Step 33: The real-time mass flow rate is calculated by normalizing the real-time correction mass difference between adjacent sampling times in the real-time correction mass sequence according to a preset sampling period. The real-time mass flow rate is then combined with the real-time correction mass at the corresponding sampling time to generate filling process data arranged in chronological order. The real-time mass flow rate reflects the change in the mass of damping oil entering the workpiece cavity per unit time under vacuum conditions.

[0069] Through the above steps, this embodiment acquires high-precision real-time mass data under a unified time reference in a vacuum environment and calculates the real-time mass flow rate corresponding to the actual filling state. This process can effectively suppress data distortion caused by pressure fluctuations or weighing response delays in a vacuum environment, providing a stable and accurate input basis for subsequent differential pressure adjustment and end-of-line pressure relief determination based on flow deviation, thereby improving the controllability, consistency, and repeatability of the damping oil precision filling process.

[0070] In one embodiment of the present invention, adjusting the first differential pressure, and triggering the end-of-line depressurization process when the real-time correction mass reaches a preset ratio of the target injection mass, includes:

[0071] Step 41: Obtain the real-time mass flow rate, convert the real-time mass flow rate and the target volumetric flow rate in the process parameters into the target mass flow rate according to the density relationship. The real-time mass flow rate reflects the mass change of oil entering the workpiece cavity per unit time, while the target mass flow rate is used to characterize the stable propulsion rate expected to be achieved during the filling process. Generate the mass flow rate deviation based on the difference between the two. The mass flow rate deviation represents the degree of deviation of the actual filling state from the target flow rate state. Calculate the first differential pressure adjustment amount based on the product of the mass flow rate deviation and the preset adjustment coefficient.

[0072] Step 42: The first differential pressure adjustment amount is superimposed with the current first differential pressure to obtain the updated first differential pressure, and an updated first differential pressure sequence is generated with the sampling time as the index. Through the serialized differential pressure update method, fine-grained control of the oil propulsion rate can be achieved in a vacuum environment, which helps to suppress the transient flow fluctuation of damping oil in the channel and improve the stability of the overall filling process.

[0073] Step 43: During the process of updating the first differential pressure sequence, the real-time corrected mass is read from the filling process data. The ratio of the real-time corrected mass to the target filling mass in the process parameters is calculated. When the ratio reaches a preset proportion, an end-of-line depressurization trigger signal is generated to trigger the end-of-line depressurization process. The real-time corrected mass represents the actual mass of oil entering the workpiece cavity after zero-point correction under vacuum conditions, while the target filling mass is the final filling amount preset in the process parameters.

[0074] Through the above steps, this embodiment constructs a dynamic differential pressure regulation mechanism based on mass flow feedback in a vacuum environment, enabling the damping oil propulsion rate to match the process setting target in real time, and accurately triggering end pressure relief when approaching the filling endpoint, thereby improving the stability, endpoint consistency and filling quality control capability of precise damping oil filling.

[0075] In one embodiment of the present invention, a preset adjustment step size upper limit is set for the first differential pressure adjustment amount to avoid excessive adjustment due to instantaneous changes in mass flow rate deviation, and the portion exceeding the preset adjustment step size upper limit is truncated during the adjustment process to prevent the system from becoming unstable due to excessive pressure adjustment.

[0076] In one embodiment of the present invention, determining the dispensing termination time and determining the final dispensing quality based on real-time correction quality includes:

[0077] Step 51: Obtain the real-time mass flow rate. When the real-time mass flow rate does not exceed the preset flow termination threshold in M ​​consecutive samples, the Mth sampling time is taken as the filling termination time, and the connecting valve is switched from the open state to the closed state at the filling termination time. The flow termination threshold is used to limit the minimum effective inflow rate of damping oil in the later stage of filling to prevent misjudgment of the endpoint due to transient flow fluctuations or measurement noise. At the filling termination time, the connecting valve is controlled to switch from the open state to the closed state to prevent oil from continuing to enter the workpiece cavity. M is preferably set to 8.

[0078] Step 52: After the connecting valve is closed, to eliminate the influence of residual pressure in the channel on the final quality determination, the absolute pressure of the oil chamber and the absolute pressure of the workpiece chamber are set as the reference absolute pressure. During the pressure holding time, the absolute pressures of the oil chamber and the workpiece chamber are collected according to a preset sampling period. It is determined that the continuous sampling values ​​are all within the preset pressure stability threshold of the reference absolute pressure. The reference absolute pressure is a unified vacuum pressure baseline established before filling, used to ensure that the system is in a stable state under conditions of no oil flow. This step ensures that there is no residual pressure driving force in the channel under vacuum conditions, thus ensuring that the final filling quality is determined solely by the actual inflow of oil.

[0079] Step 53: At the end of the pressure holding time, read the real-time correction mass corresponding to the end of the pressure holding time from the filling process data, determine the real-time correction mass as the final filling mass, and use the final filling mass as the end value of the filling process.

[0080] Through the above steps, this embodiment establishes a reliable final filling quality determination mechanism in a vacuum environment through three stages: flow termination determination, pressure stability confirmation, and quality benchmark reading. This mechanism can effectively avoid endpoint deviations caused by pressure hysteresis, residual drive, weighing errors, or flow fluctuations in a vacuum environment, making the termination point of damping oil precision filling more accurate, stable, and repeatable, thereby improving the accuracy and consistency of the overall filling process.

[0081] In one embodiment of the present invention, the workpiece is sealed and a seal test is performed, and a fixed parameter table is generated based on process parameters, filling process data, and final filling quality, including:

[0082] Step 61: Perform a sealing operation on the workpiece and record the sealing action data. The sealing action data is used to characterize the integrity of the sealing execution process, such as the closing time of the sealing mechanism and the trend of the applied force. The absolute pressure of the workpiece cavity is collected according to the preset sampling period. The Pth sampling time when the consecutive P sampling values ​​are all within the sealing detection threshold is taken as the sealing detection completion time, and sealing detection data is formed. P is preferably set to 10.

[0083] Step 62: At the moment when the seal test is completed, integrate the process temperature, target volume flow rate and target filling mass in the process parameters with the real-time mass flow rate sequence and real-time correction mass sequence in the filling process data, as well as the final filling mass, to form a filling record dataset.

[0084] Step 63: Construct the field structure of the fixed setting parameter table based on the filling record dataset and sealing test data, and write the corresponding data content according to the field to generate the fixed setting parameter table for the corresponding batch.

[0085] In one embodiment of the present invention, to further improve the reliability of workpiece sealing detection in a vacuum environment, a dual-threshold combined with a sliding sampling window method is used to analyze the stability of the absolute pressure in the workpiece cavity. During the sealing detection process, a first sealing detection threshold and a second sealing detection threshold are set. The first sealing detection threshold is used to limit the allowable deviation range of the absolute pressure in the workpiece cavity to evaluate whether the overall cavity pressure is stable under sealing conditions. The second sealing detection threshold is used to limit the maximum allowable amount of fluctuation. The absolute pressure in the workpiece cavity is continuously sampled according to a preset sampling period. When Q consecutive sampling values ​​are all within the preset range corresponding to the first sealing detection threshold, the Qth sampling time is determined as the sealing stability judgment time, indicating that the workpiece cavity pressure after sealing has reached a continuously stable state for the first time. The difference between the maximum and minimum sampling values ​​is calculated within a preset sliding sampling window as the fluctuation amplitude. When the fluctuation amplitude does not exceed the second sealing detection threshold, the fluctuation requirement is satisfied. When the sampling interval where the sealing stability judgment time is located completely overlaps with the sliding sampling window corresponding to the fluctuation amplitude, and both judgment conditions are satisfied, i.e., when both the overall stability requirement and the local fluctuation requirement are simultaneously met, the sealing detection is determined to be qualified. Preferably, Q is set to 10.

[0086] This embodiment, through the aforementioned dual-threshold synergy and sliding window fluctuation analysis mechanism, can perform more accurate and hierarchical detection of the pressure in the sealed workpiece cavity under vacuum conditions. This avoids misjudgment caused by single-point pressure anomalies and can also effectively identify small irregular pressure fluctuations caused by micro-leakage or residual channel effects. As a result, this invention can make a multi-dimensional comprehensive judgment on the sealing status of the workpiece during the precision filling of damping oil under vacuum conditions, thereby improving the robustness and reliability of the sealing detection.

[0087] It should be noted that the interval and threshold sizes are set for ease of comparison. The size of the threshold depends on the amount of sample data and the base number set by those skilled in the art for each set of sample data, as long as it does not affect the proportional relationship between the parameter and the quantized value. Furthermore, the above formulas are all dimensionless calculations, and the formulas are derived from software simulations using a large amount of collected data to obtain the most recent real-world results. The preset parameters in the formulas are set by those skilled in the art according to the actual situation.

[0088] The embodiments of the present invention have been described above, but the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms based on the guidance of the present embodiments, all of which are within the protection scope of the present embodiments.

Claims

1. A method for precise filling of damping oil based on vacuum environment control, characterized in that, Includes the following steps: Step 1: Establish a reference absolute pressure environment and set the process temperature in the oil chamber and workpiece chamber, obtain the zero point value of the platform scale, and set the process parameters. Step 2: Under the reference absolute pressure environment, detect the absolute pressure of the oil chamber and the absolute pressure of the workpiece chamber. When it is determined that the oil chamber and the workpiece chamber are under the same pressure, control the connecting valve to open for pre-wetting. Step 3: Determine the first pressure difference based on the process parameters, the equivalent radius of the channel, and the channel length, and set the pressure difference between the oil chamber and the workpiece chamber based on the reference absolute pressure; Step 4: Under the first differential pressure, open the connecting valve to push the damping oil into the workpiece cavity. Obtain the real-time correction mass based on the zero point value of the platform scale according to the preset sampling cycle, and form the filling process data, which includes the real-time correction mass and the real-time mass flow rate. Step 5: Adjust the first differential pressure based on the target volumetric flow rate in the filling process data and process parameters. When the real-time correction mass reaches a preset ratio of the target filling mass, trigger the end-of-line depressurization process, including: Step 41: Obtain the real-time mass flow rate, convert the real-time mass flow rate and the target volumetric flow rate in the process parameters into the target mass flow rate according to the density relationship, generate the mass flow rate deviation based on the difference between the two, and calculate the first differential pressure adjustment amount based on the product of the mass flow rate deviation and the preset adjustment coefficient. Step 42: The first differential pressure adjustment amount is superimposed with the current first differential pressure to obtain the updated first differential pressure, and an updated first differential pressure sequence is generated with the sampling time as the index; Step 43: During the process of updating the first differential pressure sequence, the real-time correction mass is read from the filling process data, and the ratio of the real-time correction mass to the target filling mass in the process parameters is calculated. When the ratio reaches the preset ratio, the end pressure relief trigger signal is generated to trigger the end pressure relief process. Step 6: During the final depressurization process, determine the injection termination time based on the injection process data, close the connecting valve, and maintain the reference absolute pressure of the oil chamber and the workpiece chamber during the pressure holding time. Determine the final injection quality based on the real-time correction quality at the end of the pressure holding time. Step 7: Perform sealing and sealing tests on the workpiece, and generate a fixed setting parameter table based on process parameters, filling process data, and final filling quality.

2. The method for precise filling of damping oil based on vacuum environment control according to claim 1, characterized in that, The process parameters include oil viscosity, oil density, target volumetric flow rate, and target injection mass.

3. The method for precise filling of damping oil based on vacuum environment control according to claim 1, characterized in that, The absolute pressure of the oil chamber and the absolute pressure of the workpiece chamber are detected. When it is determined that the oil chamber and the workpiece chamber are under the same pressure, the connecting valve is opened to perform pre-wetting, including: Step 11: Collect the absolute pressure of the oil chamber and the absolute pressure of the workpiece chamber respectively, and determine that the oil chamber and the workpiece chamber are under the same pressure when the difference between the two does not exceed the preset pressure difference threshold. Step 12: When the oil chamber and the workpiece chamber are under the same pressure, control the connecting valve to open at a preset small opening, and maintain the preset small opening during the pre-wetting time. Step 13: After the pre-wetting time is over, close the connecting valve and use the liquid distribution state generated at the inlet of the workpiece cavity as the continuous oil film interface.

4. The method for precise filling of damping oil based on vacuum environment control according to claim 1, characterized in that, Determine the first pressure difference, and set the pressure difference between the oil chamber and the workpiece chamber based on the reference absolute pressure, including: Step 21: Extract the oil viscosity and target volumetric flow rate from the process parameters, and extract the channel equivalent radius and channel length from the channel structure. Calculate the first pressure difference based on the Poiseuille laminar flow model. Step 22: Under the condition that the absolute pressure of the workpiece cavity is kept at the reference absolute pressure, the absolute pressure of the oil cavity is set to the sum of the reference absolute pressure and the first pressure difference, and the absolute pressure of the oil cavity is monitored with a fixed sampling period, so that the difference between the maximum and minimum values ​​of the absolute pressure of the oil cavity collected in N consecutive samples does not exceed the preset stable threshold. Step 23: Calculate the difference between the absolute pressure of the oil chamber and the absolute pressure of the workpiece chamber using data collected N times consecutively as the actual pressure difference. When the actual pressure difference does not exceed the preset steady-state threshold of pressure difference, it is determined that the first pressure difference is in a steady state.

5. The method for precise filling of damping oil based on vacuum environment control according to claim 1, characterized in that, Acquire real-time calibration quality and generate filling process data, including: Step 31: After the first differential pressure reaches a steady state, control the connecting valve to switch from the closed state to the open state, and start the sampling timer corresponding to the preset sampling period to execute a unified time reference; Step 32: Read the mass measurement value from the platform scale at each sampling time, calculate the real-time corrected mass at that sampling time based on the zero point value of the platform scale, record the real-time corrected mass and the time label of the corresponding sampling time as a real-time corrected mass sequence arranged in time order, and continuously detect the real-time corrected mass sequence according to the sampling period, and remove abnormal jump values. Step 33: The real-time quality flow rate is obtained by normalizing the difference in real-time correction quality between adjacent sampling times in the real-time correction quality sequence according to a preset sampling period. The real-time quality flow rate is then combined with the real-time correction quality at the corresponding sampling time to generate the refueling process data arranged in chronological order.

6. The method for precise filling of damping oil based on vacuum environment control according to claim 1, characterized in that, A preset adjustment step size upper limit is set for the first differential pressure adjustment amount, and the portion exceeding the preset adjustment step size upper limit is truncated during the adjustment process.

7. The method for precise filling of damping oil based on vacuum environment control according to claim 1, characterized in that, Determine the refueling termination time and the final refueling quality based on real-time calibration quality, including: Step 51: Obtain the real-time quality flow rate. When the real-time quality flow rate is not higher than the preset flow termination threshold in M ​​consecutive samplings, the Mth sampling time is taken as the refueling termination time, and the connecting valve is switched from the open state to the closed state at the refueling termination time. Step 52: After the connecting valve is closed, the absolute pressure of the oil chamber and the absolute pressure of the workpiece chamber are set as the reference absolute pressure. During the pressure holding time, the absolute pressure of the oil chamber and the absolute pressure of the workpiece chamber are collected according to the preset sampling period. It is determined that the continuous sampling values ​​are all within the preset pressure stability threshold of the reference absolute pressure. Step 53: At the end of the pressure holding time, read the real-time correction mass corresponding to the end of the pressure holding time from the filling process data, determine the real-time correction mass as the final filling mass, and use the final filling mass as the end value of the filling process.

8. The method for precise filling of damping oil based on vacuum environment control according to claim 1, characterized in that, The workpiece is sealed and tested for sealing, and a fixed parameter table is generated based on process parameters, filling process data, and final filling quality, including: Step 61: Perform a sealing operation on the workpiece, record the sealing action data, and collect the absolute pressure of the workpiece cavity according to the preset sampling period. The Pth sampling time when the consecutive P sampling values ​​are all within the sealing detection threshold is taken as the sealing detection completion time, and sealing detection data is formed. Step 62: At the moment when the seal test is completed, integrate the process temperature, target volume flow rate and target filling mass in the process parameters with the real-time mass flow rate sequence and real-time correction mass sequence in the filling process data, as well as the final filling mass, to form a filling record dataset. Step 63: Construct the field structure of the fixed setting parameter table based on the filling record dataset and sealing test data, and write the corresponding data content according to the field to generate the fixed setting parameter table for the corresponding batch.

9. The method for precise filling of damping oil based on vacuum environment control according to claim 8, characterized in that, During the sealing test, a first sealing test threshold and a second sealing test threshold are set respectively. The absolute pressure of the workpiece cavity is continuously collected according to a preset sampling period. When the Q consecutive sampling values ​​are all within the preset range corresponding to the first sealing test threshold, the Qth sampling time is determined as the sealing stability judgment time. Within the preset sliding sampling window, the difference between the maximum and minimum sampled values ​​is calculated as the fluctuation amplitude. When the fluctuation amplitude does not exceed the second sealing detection threshold, the fluctuation requirement is deemed to be met. When the sampling interval at the sealing stability determination time completely overlaps with the sliding sampling window corresponding to the fluctuation amplitude and both determination conditions are met, the sealing detection is deemed to be qualified.

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