An Adaptive Pressure Adjustment Method for Injection Molding Machine Accumulators Based on Operating Condition Sensing

Abstract

This invention relates to an adaptive pressure adjustment method for an injection molding machine accumulator based on operating condition perception, belonging to the field of injection molding machine technology. The method includes starting the equipment and collecting the initial pressure and current oil temperature of the accumulator; determining the leakage rate based on the initial pressure and current oil temperature; determining a charging pressure threshold based on the current oil temperature; if the current oil temperature is greater than a preset oil temperature threshold, calculating the temperature difference between the current oil temperature and the preset oil temperature threshold; adjusting the charging pressure threshold according to the leakage rate and temperature difference to obtain a secondary pressure threshold; determining the pressure volume based on the secondary pressure threshold and a preset pressure model; substituting the pressure volume into a preset oil volume model to obtain the hydraulic oil volume during the injection process; and performing injection when the initial pressure of the accumulator reaches the secondary pressure threshold and the hydraulic oil volume is greater than the preset hydraulic oil threshold. This application has the effect of improving efficiency under different operating conditions.

Description

Technical Field

[0001] This invention relates to the field of injection molding machine technology, and in particular to an adaptive adjustment method for accumulator pressure in injection molding machines based on working condition perception. Background Technology

[0002] In the injection molding industry, accumulators are key equipment in the hydraulic system of injection molding machines, and their performance directly affects the quality of plastic products, production efficiency, and energy consumption.

[0003] In existing technologies, injection molding machine accumulators typically employ a fixed pressure threshold triggering mechanism for pressure control. A single pressure value is set via an external level sensor; when the pressure within the accumulator reaches this fixed value, the system determines that charging is complete. This control method can meet basic injection molding production needs, providing the necessary energy to the hydraulic system and ensuring the smooth operation of the injection molding process. It has been widely used in traditional injection molding production scenarios.

[0004] Different situations require different hydraulic oil, and the corresponding threshold settings require the accumulator to be charged to a fixed high pressure before releasing energy. This cannot be adjusted according to the actual situation, resulting in serious energy waste, extended production cycles, and limited efficiency. Summary of the Invention

[0005] To improve efficiency under different operating conditions, this invention provides a method for adaptive adjustment of accumulator pressure in injection molding machines based on operating condition perception.

[0006] This invention provides a method for adaptive adjustment of accumulator pressure in injection molding machines based on operating condition perception, employing the following technical solution: An adaptive pressure adjustment method for accumulators in injection molding machines based on operating condition perception includes: Start the equipment and collect the initial pressure and current oil temperature of the accumulator; The leakage rate is determined based on the initial pressure and the current oil temperature; Determine the charging pressure threshold based on the current oil temperature; If the current oil temperature is greater than the preset oil temperature threshold, calculate the temperature difference between the current oil temperature and the preset oil temperature threshold. The secondary pressure threshold is obtained by adjusting the charging pressure threshold based on the leakage rate and the temperature difference. The pressure volume is determined based on the secondary pressure threshold and the preset pressure model. The hydraulic oil volume during the injection molding process is obtained by substituting the pressure volume into a preset oil volume model. Injection is performed when the initial pressure of the accumulator reaches the secondary pressure threshold and the hydraulic oil volume is greater than the preset hydraulic oil threshold.

[0007] By adopting the above technical solution, the initial pressure and current oil temperature of the accumulator are collected, the leakage rate is determined and the charging pressure threshold is calculated. Then, the secondary pressure threshold is obtained by correcting the temperature difference and finally injecting. This allows the accumulator pressure to be adjusted in real time according to the working conditions, ensuring the pressure stability of the injection molding process and improving the efficiency under different working conditions.

[0008] Optionally, determining the leakage rate includes: The pressure difference is determined based on the initial pressure and the charging pressure threshold. The leakage value is obtained by multiplying the pressure difference, the preset leakage area, and the preset leakage parameters. The viscosity ratio is obtained by combining the temperature difference with a preset viscosity temperature coefficient. The hydraulic oil viscosity is obtained by multiplying the preset initial hydraulic oil viscosity by the viscosity ratio. The leakage rate is obtained by dividing the leakage value by the hydraulic oil viscosity.

[0009] By adopting the above technical solution, the leakage value is calculated based on the pressure difference, leakage area and leakage parameters. The leakage rate is obtained by correcting the hydraulic oil viscosity with the temperature difference, which ensures the accuracy of the leakage rate and provides a reliable basis for subsequent adjustments.

[0010] Optionally, adjusting the charging pressure threshold based on the leakage rate and the temperature difference to obtain the secondary pressure threshold includes: Determine the leakage rate difference based on the leakage rate; When the leakage rate difference is 0, the charging pressure threshold is used as the secondary pressure threshold.

[0011] Optional methods for determining the leakage rate difference include: Retrieve historical and current leakage rates based on the stated leakage rate; The leakage rate difference is calculated based on the historical leakage rate and the current leakage rate.

[0012] By adopting the above technical solution, the leakage rate difference is determined, thereby providing data reference for judging the condition of the hydraulic system. When the leakage rate difference is 0, it indicates that no change has occurred in the hydraulic oil and no adjustment is required.

[0013] Optionally, adjusting the charging pressure threshold based on the leakage rate and the temperature difference to obtain the secondary pressure threshold further includes: When the leakage rate difference is not 0, the charging pressure threshold is updated based on the leakage rate and the temperature difference. The updated charging pressure threshold is corrected according to the preset proportional gain to obtain the secondary pressure threshold.

[0014] By adopting the above technical solution, when the leakage rate difference is not 0, it indicates that the hydraulic oil is leaking. It is necessary to update and adjust the charging pressure threshold according to the leakage rate and temperature difference to obtain the secondary pressure threshold.

[0015] Optionally, updating the charging pressure threshold based on the leakage rate and the temperature difference includes: When the temperature difference is not 0, a correction value is determined based on the preset rated leakage rate and the leakage rate difference. The charging coefficient is determined based on the correction value and the preset rated ratio; Update the charging pressure threshold based on the charging coefficient; When the temperature difference is 0, the charging pressure threshold is not updated.

[0016] By adopting the above technical solution, the charging pressure threshold is dynamically adjusted according to the change in leakage rate. When the oil temperature changes, the viscosity of the hydraulic oil will also change accordingly, and the pressure needs to be adjusted accordingly. By adjusting the charging pressure of the accumulator to compensate for the impact, the pressure holding capability is improved, and pressure stability is ensured.

[0017] Optionally, the secondary pressure threshold is obtained by correcting the updated charging pressure threshold according to a preset proportional gain, including: The leakage rate difference is calculated by subtracting the preset leakage rate threshold from the leakage rate. The corrected pressure value is calculated based on the leakage rate difference and the preset proportional gain; The secondary pressure threshold is calculated based on the charging pressure threshold and the corrected pressure value.

[0018] By adopting the above technical solution, the difference between the leakage rate and the leakage rate threshold is multiplied by the proportional gain to obtain the corrected pressure value. This value is then multiplied by the charging pressure threshold to obtain the secondary pressure threshold, thereby realizing the adjustment of the charging pressure threshold correction and improving the response speed and adjustment accuracy.

[0019] In summary, this application includes at least one of the following beneficial technical effects: 1. Collect the initial pressure and current oil temperature of the accumulator, determine the leakage rate and calculate the charging pressure threshold, and then correct it according to the temperature difference to obtain the secondary pressure threshold. Finally, inject the accumulator pressure so that it can be adjusted in real time according to the working conditions, ensuring the pressure stability of the injection molding process and improving the efficiency under different working conditions. 2. By adjusting the dynamic pressure, energy redundancy is reduced, the heating and cooling energy consumption of the hydraulic system is decreased, energy efficiency is improved, charging time is shortened, adaptability to high-speed injection molding scenarios is improved, production continuity is enhanced, and efficiency is further improved. 3. Through an automatic compensation mechanism, the impact of variables such as oil temperature and leakage is reduced, and the charging pressure threshold can be adjusted in real time according to the working conditions, thereby reducing the product defect rate and enhancing the stability of the equipment. Attached Figure Description

[0020] Figure 1 This is a flowchart of a method for adaptive adjustment of accumulator pressure in an injection molding machine based on working condition perception, according to an embodiment of the present invention. Figure 2 This is a flowchart of a method for determining the leakage rate according to an embodiment of the present invention. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0022] This application discloses a method for adaptive adjustment of accumulator pressure in injection molding machines based on operating condition perception.

[0023] Reference Figure 1 An adaptive pressure adjustment method for accumulators in injection molding machines based on operating condition perception includes the following steps: Step S100: Start the equipment and collect the initial pressure and current oil temperature of the accumulator.

[0024] The initial pressure refers to the pressure value that the accumulator is pre-charged after initial stabilization. It is collected in real time by a pressure sensor, which is preset by technicians according to the actual situation and will not be described in detail here.

[0025] The current oil temperature refers to the temperature value of the hydraulic oil when it is running stably. It is collected in real time by a temperature sensor. The temperature sensor is preset by technicians according to the actual situation, which will not be described in detail here.

[0026] The equipment is an accumulator for injection molding machines, which will not be described in detail here.

[0027] Step S101: Determine the leakage rate based on the initial pressure and current oil temperature.

[0028] Leakage rate refers to the ratio of hydraulic oil leakage caused by changes in oil temperature per unit time, and is used to quantify the degree of leakage in a hydraulic system.

[0029] Reference Figure 2 Determining the leakage rate includes the following steps: Step S200: Determine the pressure difference based on the initial pressure and the charging pressure threshold.

[0030] Pressure difference refers to the difference used to determine pressure conditions, which is obtained by subtracting the initial pressure from the charging pressure threshold.

[0031] Step S201: Multiply the pressure difference, the preset leakage area, and the preset leakage parameters to obtain the leakage value.

[0032] The leakage area refers to the effective leakage area of ​​the sealing surface of the hydraulic system, which is preset by technicians according to the actual situation and will not be elaborated here.

[0033] Leakage parameters refer to empirical coefficients related to sealing materials and structures, which are preset by technicians based on actual conditions and will not be elaborated here.

[0034] Leakage value refers to the data value used to determine leakage situations.

[0035] The leakage value is calculated by substituting the pressure difference, leakage area, and leakage parameters into the formula: [Formula omitted for brevity] ;in, For leakage values, Leakage coefficient, For the leak area, This is the pressure difference.

[0036] Step S202: Obtain the viscosity ratio by combining the temperature difference and the preset viscosity temperature coefficient.

[0037] The viscosity-temperature coefficient refers to the coefficient by which the viscosity of hydraulic oil changes with temperature. It is preset by technicians according to actual conditions and will not be elaborated here.

[0038] Viscosity ratio refers to the ratio used to determine the viscosity of hydraulic oil.

[0039] The viscosity ratio is calculated by substituting the temperature difference and the viscosity temperature coefficient into the formula, which is: ;in, This refers to the viscosity ratio. This is the temperature difference value. The viscosity temperature coefficient, It is the natural base (common knowledge).

[0040] Step S203: Multiply the preset initial hydraulic oil viscosity by the viscosity ratio to obtain the hydraulic oil viscosity.

[0041] The preliminary hydraulic oil viscosity refers to the hydraulic oil viscosity at standard temperature, which is preset by technicians according to actual conditions and will not be elaborated here.

[0042] Hydraulic oil viscosity refers to the viscosity of hydraulic oil at the current oil temperature.

[0043] The hydraulic oil viscosity is calculated by substituting the preliminary hydraulic oil viscosity and viscosity ratio into the formula, which is: ;in, The viscosity of the hydraulic oil at the current oil temperature. Reference temperature The viscosity of the hydraulic oil below, This represents the viscosity ratio.

[0044] Step S204: Divide the leakage value by the hydraulic oil viscosity to obtain the leakage rate.

[0045] The leakage rate is calculated by dividing the leakage value by the hydraulic oil viscosity and substituting the result into the formula: [Formula omitted for brevity] ;in, Leakage rate, For hydraulic oil viscosity, This is the leakage value.

[0046] Step S102: Determine the charging pressure threshold based on the current oil temperature.

[0047] The charging pressure threshold refers to the minimum charging gas pressure of the accumulator set to ensure the operation of subsequent functions.

[0048] The charging pressure threshold is obtained by inputting the current oil temperature into the preset charging database. The charging database is a database that is preset by technicians according to the actual situation. The charging database contains a relationship table between the current oil temperature and the charging pressure threshold. The relationship table is preset by technicians according to the actual situation and will not be described in detail here.

[0049] Step S103: If the current oil temperature is greater than the preset oil temperature threshold, calculate the temperature difference between the current oil temperature and the preset oil temperature threshold.

[0050] The oil temperature threshold refers to the highest allowable oil temperature critical value of the equipment, which is preset by technicians according to the actual situation, and will not be elaborated here.

[0051] Temperature difference refers to the difference between the current oil temperature and the oil temperature threshold.

[0052] If the current oil temperature is greater than the oil temperature threshold, it means that the oil temperature is sufficient and the machine can run, and then the temperature difference can be calculated.

[0053] Step S104: Adjust the charging pressure threshold according to the leakage rate and temperature difference to obtain the secondary pressure threshold.

[0054] The secondary pressure threshold refers to the corrected charging pressure value after compensation and adjustment.

[0055] The specific method for obtaining the secondary pressure threshold is described in steps S300 to S703, and will not be repeated here.

[0056] Step S105: Determine the pressure volume based on the secondary pressure threshold and the preset pressure model.

[0057] A pressure model is a mathematical model that describes the relationship between pressure and volume. It is set up in advance by technicians according to the actual situation and will not be elaborated on here.

[0058] Pressure volume refers to the gas volume required by the accumulator under the secondary pressure threshold.

[0059] The secondary pressure threshold is input into the pressure model to obtain the corresponding pressure volume. The pressure model is as follows: P1 represents the pre-charged gas pressure inside the accumulator, and V1 represents the fixed total volume of the accumulator; these are the initial fixed parameters of the accumulator. As the accumulator charges and discharges, its internal pressure and volume change accordingly: when the accumulator finishes discharging, its internal pressure drops to P2, and the volume inside the accumulator is V2; while when the accumulator finishes charging, its internal pressure rises to P3, and the corresponding volume inside the accumulator is V3.

[0060] Step S106: Substitute the pressure volume into the preset oil volume model to obtain the hydraulic oil volume during the injection molding process.

[0061] The hydraulic fluid volume model refers to a mathematical model that represents the relationship between pressure volume and hydraulic fluid volume.

[0062] Hydraulic oil volume refers to the minimum volume of hydraulic oil required to complete a single injection molding process.

[0063] The oil volume model is a curve within the 3D model. Once one of the coordinates is determined, a unique point can be found. The coordinates of this point correspond to the values ​​of the three parameters, which are preset by technicians according to the actual situation and will not be elaborated here.

[0064] Step S107: When the initial pressure of the accumulator reaches the secondary pressure threshold and the hydraulic oil volume is greater than the preset hydraulic oil threshold, injection is performed.

[0065] The hydraulic oil threshold refers to the minimum amount of hydraulic oil required for a single injection. It is preset by technicians according to the actual situation and will not be elaborated here.

[0066] When the secondary pressure threshold is reached and the hydraulic oil volume is greater than the hydraulic oil threshold, it indicates that the energy release condition has been met and the hydraulic oil volume is sufficient, and injection molding can proceed.

[0067] The secondary pressure threshold is obtained by adjusting the charging pressure threshold based on the leakage rate and temperature difference, including the following steps: Step S300: Determine the leakage rate difference based on the leakage rate.

[0068] Leakage rate difference refers to the difference data used to determine the leakage status of hydraulic oil.

[0069] Specific methods for determining the leakage rate difference include: Step S400: Retrieve historical leakage rates and current leakage rates based on the leakage rate.

[0070] Historical leakage rate refers to the leakage rate data from the last historical period.

[0071] The current leakage rate refers to the leakage rate data obtained in this real-time event.

[0072] The system inside the injection molding machine records relevant data in real time and uses it as the leakage rate. When needed, the leakage rate can be retrieved directly.

[0073] Step S401: Calculate the difference in leakage rates based on historical leakage rates and current leakage rates.

[0074] The leakage rate difference refers to the change in leakage rate after one charge-discharge cycle.

[0075] The difference between the historical leakage rate and the current leakage rate is obtained.

[0076] Step S301: When the leakage rate difference is 0, the charging pressure threshold is used as the secondary pressure threshold.

[0077] When the difference in leakage rate is 0, it means that nothing has changed and no adjustment is needed.

[0078] The process of adjusting the charging pressure threshold based on the leakage rate and temperature difference to obtain the secondary pressure threshold also includes the following steps: Step S500: When the leakage rate difference is not 0, update the charging pressure threshold based on the leakage rate and temperature difference.

[0079] When the leakage rate difference is not 0, it indicates that there is a leakage in the hydraulic oil, and the charging pressure threshold needs to be updated.

[0080] Updating the charging pressure threshold based on leakage rate and temperature difference includes the following steps: Step S600: When the temperature difference is not 0, determine the correction value based on the preset rated leakage rate and the leakage rate difference.

[0081] The rated leakage rate refers to the preset standard leakage rate, which is set in advance by technicians according to the actual situation, and will not be elaborated here.

[0082] The correction value refers to the amount of correction used to adjust the charging pressure threshold.

[0083] The correction value is calculated by substituting the rated leakage rate and the difference in leakage rate into the formula, which is: ;in, For correction amount, The change in leakage rate This is the rated leakage rate.

[0084] Step S601: Determine the charging coefficient based on the correction value and the preset rated ratio.

[0085] The rated ratio refers to the ratio coefficient between the correction value and the pressure threshold, with a value of 1. It is preset by technicians according to the actual situation and will not be elaborated here.

[0086] The charging coefficient refers to the coefficient used to update the charging pressure threshold.

[0087] Substituting the correction value and the rated ratio into the formula, the charging coefficient is calculated. The formula is: ;in, The energy coefficient is... This is a correction amount.

[0088] Step S602: Update the charging pressure threshold based on the charging coefficient.

[0089] Substituting the charging coefficient and charging pressure threshold into the formula updates the charging pressure threshold. The formula is as follows: ;in, The energy coefficient is... The adjusted charging pressure threshold. The charging pressure threshold before adjustment.

[0090] Step S603: When the temperature difference is 0, the charging pressure threshold is not updated.

[0091] When the temperature difference is 0, it means that nothing has changed and there is no need to update the charging pressure threshold.

[0092] Step S501: Correct the updated charging pressure threshold according to the preset proportional gain to obtain the secondary pressure threshold.

[0093] Proportional gain refers to the gain coefficient used to correct the pressure value. It is preset by technicians according to the actual situation and will not be elaborated here.

[0094] The process of correcting the updated charging pressure threshold based on a preset proportional gain to obtain the secondary pressure threshold includes the following steps: Step S700: Subtract the preset leakage rate threshold from the leakage rate to calculate the leakage rate difference.

[0095] The leakage rate threshold refers to the maximum allowable leakage rate, which is preset by technicians according to the actual situation and will not be elaborated here.

[0096] Leakage rate difference refers to the difference between the current leakage rate and the threshold.

[0097] The leakage rate difference is calculated by substituting the leakage rate and leakage rate threshold into the formula, which is: ;in, Due to poor leakage rate, Given the current leakage rate, This is the leakage rate threshold.

[0098] Step S701: Calculate the corrected pressure value based on the leakage rate difference and the preset proportional gain.

[0099] The correction pressure value refers to the amount of correction used to adjust the charging pressure threshold.

[0100] The corrected pressure value is calculated by substituting the leakage rate difference and the proportional gain value into the formula, which is: ;in, To correct the pressure value, Due to poor leakage rate, This is the proportional gain.

[0101] Step S702: Calculate the secondary pressure threshold based on the charging pressure threshold and the corrected pressure value.

[0102] The secondary pressure threshold is calculated by substituting the charging pressure threshold and the corrected pressure value into the formula. The formula is as follows: ;in, As the reference charging pressure, To correct the pressure value.

[0103] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A method for adaptive adjustment of accumulator pressure in an injection molding machine based on working condition perception, characterized in that, include: Start the equipment and collect the initial pressure and current oil temperature of the accumulator; The leakage rate is determined based on the initial pressure and the current oil temperature; The charging pressure threshold is determined based on the current oil temperature. The charging pressure threshold refers to the minimum charging gas pressure of the accumulator set to ensure the requirements of subsequent operations. If the current oil temperature is greater than the preset oil temperature threshold, calculate the temperature difference between the current oil temperature and the preset oil temperature threshold. The secondary pressure threshold is obtained by adjusting the charging pressure threshold based on the leakage rate and the temperature difference. The pressure volume is determined based on the secondary pressure threshold and the preset pressure model. The hydraulic oil volume during the injection molding process is obtained by substituting the pressure volume into a preset oil volume model. When the initial pressure of the accumulator reaches the secondary pressure threshold and the hydraulic oil quantity is greater than the preset hydraulic oil threshold, injection is performed; Determining the leakage rate includes: The pressure difference is determined based on the initial pressure and the charging pressure threshold. The leakage value is obtained by multiplying the pressure difference, the preset leakage area, and the preset leakage parameters. The viscosity ratio is obtained by combining the temperature difference with a preset viscosity temperature coefficient. The hydraulic oil viscosity is obtained by multiplying the preset initial hydraulic oil viscosity by the viscosity ratio. The leakage rate is obtained by dividing the leakage value by the hydraulic oil viscosity.

2. The method for adaptive adjustment of accumulator pressure in injection molding machines based on working condition perception as described in claim 1, characterized in that, The secondary pressure threshold is obtained by adjusting the charging pressure threshold based on the leakage rate and the temperature difference, including: Determine the leakage rate difference based on the leakage rate; When the leakage rate difference is 0, the charging pressure threshold is used as the secondary pressure threshold. Methods for determining the leakage rate difference include: Retrieve historical and current leakage rates based on the stated leakage rate; The leakage rate difference is calculated based on the historical leakage rate and the current leakage rate.

3. The method for adaptive adjustment of accumulator pressure in injection molding machines based on working condition perception according to claim 2, characterized in that, The secondary pressure threshold is obtained by adjusting the charging pressure threshold based on the leakage rate and the temperature difference, and further includes: When the leakage rate difference is not 0, the charging pressure threshold is updated based on the leakage rate and the temperature difference. The updated charging pressure threshold is corrected according to the preset proportional gain to obtain the secondary pressure threshold.

4. The method for adaptive adjustment of accumulator pressure in injection molding machines based on working condition perception according to claim 3, characterized in that, Updating the charging pressure threshold based on the leakage rate and the temperature difference includes: When the temperature difference is not 0, a correction value is determined based on the preset rated leakage rate and the leakage rate difference. The charging coefficient is determined based on the correction value and the preset rated ratio; Update the charging pressure threshold based on the charging coefficient; When the temperature difference is 0, the charging pressure threshold is not updated.

5. The method for adaptive adjustment of accumulator pressure in injection molding machines based on working condition perception according to claim 3, characterized in that, The secondary pressure threshold is obtained by correcting the updated charging pressure threshold according to a preset proportional gain, including: The leakage rate difference is calculated by subtracting the preset leakage rate threshold from the leakage rate. The corrected pressure value is calculated based on the leakage rate difference and the preset proportional gain; The secondary pressure threshold is calculated based on the charging pressure threshold and the corrected pressure value.

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