Pressure maintaining control method, device and equipment for injection molding process and medium

Abstract

The invention discloses a pressure maintaining control method, device and equipment for an injection molding process and a medium, and relates to the technical field of injection molding. The method comprises the steps that first pressure maintaining pressure for maintaining pressure on a first surface of a target injection molding part, second pressure maintaining pressure for maintaining pressure on a second surface of the target injection molding part, first pressure maintaining duration for maintaining pressure on the first surface and second pressure maintaining duration for maintaining pressure on the second surface are determined; the wall thickness of the first surface is smaller than that of the second surface; controlling the injection molding machine to perform pressure maintaining operation on the first surface according to the first pressure maintaining pressure and the first pressure maintaining duration under the condition of determining that the cavity of the mold is completely filled with the plastic melt; and after determining that the first surface completes the pressure maintaining operation, controlling the injection molding machine to perform pressure maintaining operation on the second surface according to the second pressure maintaining pressure and the second pressure maintaining duration. According to the method, material shrinkage of areas with different wall thicknesses can be controlled in a targeted manner, deformation caused by shrinkage difference is reduced, and the appearance quality of a target injection molding part is improved.

Description

Technical Field

[0001] The present application relates to the field of injection molding technology, and in particular to a pressure holding control method, device, equipment and medium for an injection molding process. Background Art

[0002] In the production process of automotive interior and exterior decorative parts, flange designs are usually used to enhance their aesthetics and functionality. However, the wall thickness of these flange structures is usually smaller than the wall thickness of their main surface. Under standard injection molding pressure holding process conditions, due to the characteristics of material cooling and shrinkage, the shrinkage of the flange area will be smaller than that of the main surface. This shrinkage difference causes significant deformation problems of decorative parts after injection molding, especially in parts such as wheel eyebrows, spoilers, electroplated decorative parts, luggage rack decorative parts and roof decorative parts. This phenomenon seriously affects the appearance quality of decorative parts. Summary of the invention

[0003] In response to the above-mentioned technical problems, the embodiments of the present application provide a pressure holding control method, device, equipment and medium for an injection molding process, which can specifically control the material shrinkage in areas with different wall thicknesses, thereby reducing deformation caused by shrinkage differences, helping to ensure the shape and dimensional accuracy of the target injection molded parts, and improving the overall appearance quality of the target injection molded parts.

[0004] The technical solution of this application is implemented as follows:

[0005] In a first aspect, an embodiment of the present application provides a pressure holding control method for an injection molding process, comprising:

[0006] Determining a first holding pressure for holding a first surface of a target injection molded part and a second holding pressure for holding a second surface of the target injection molded part, and determining a first holding time for holding the first surface and a second holding time for holding the second surface; a wall thickness of the first surface is less than a wall thickness of the second surface;

[0007] When it is determined that the cavity of the mold for molding the target injection molded part is completely filled with the plastic melt, controlling the injection molding machine to perform a holding pressure operation on the first surface according to the first holding pressure and the first holding pressure duration;

[0008] After determining that the injection molding machine completes the pressure holding operation on the first surface, controlling the injection molding machine to perform the pressure holding operation on the second surface according to the second pressure holding pressure and the second pressure holding time.

[0009] In some embodiments, determining a first holding pressure for holding a first surface of a target injection molded part and a second holding pressure for holding a second surface of the target injection molded part includes:

[0010] determining a maximum rated pressure of the injection molding machine;

[0011] The first holding pressure and the second holding pressure are determined based on the maximum rated pressure.

[0012] In some embodiments, the first holding pressure is less than a first multiple of the maximum rated pressure, the second holding pressure is within a target range, the minimum value of the target range is a second multiple of the maximum rated pressure, and the maximum value of the target range is a third multiple of the maximum rated pressure; the first multiple is less than the second multiple, and the second multiple is less than the third multiple.

[0013] In some embodiments, determining a first holding time for holding pressure on the first surface and a second holding time for holding pressure on the second surface includes:

[0014] Obtaining a first time point at which the mold cavity of the mold is filled with the plastic melt in a first volume ratio and a second time point at which the mold cavity of the mold is filled with the plastic melt in a second volume ratio; the first volume ratio is smaller than the second volume ratio;

[0015] Determine, by using a mold flow analysis method, a third time point at which the freezing degree of the first surface reaches a first freezing ratio and a fourth time point at which the freezing degree of the second surface reaches a second freezing ratio; the first freezing ratio is less than the second freezing ratio;

[0016] Determine the first pressure-holding time based on the second time point and the third time point, and determine the second pressure-holding time based on the first time point and the fourth time point;

[0017] The first time point, the second time point, the third time point and the fourth time point are all measured based on the time when the injection molding machine starts to inject the plastic melt into the cavity of the mold.

[0018] In some embodiments, before determining a first holding pressure for holding a first surface of a target injection molded part and a second holding pressure for holding a second surface of the target injection molded part, and determining a first holding time for holding the first surface and a second holding time for holding the second surface, the method further includes:

[0019] Controlling the injection molding machine to inject the plastic melt into the mold cavity of the mold in a manner of gradually increasing the injection amount;

[0020] When it is determined that the mold cavity is completely filled with the plastic melt, the injection molding machine is controlled to lock the injection process parameters involved in the process of the injection molding machine injecting the plastic melt into the mold cavity.

[0021] In some embodiments, before controlling the injection molding machine to inject the plastic melt into the mold cavity of the mold in a manner of gradually increasing the injection amount, the method further includes:

[0022] The temperature control device is instructed to control the temperature of the mold within a first set temperature range, and to control the temperature of the plastic melt within a second set temperature range.

[0023] In some embodiments, the injection molding process parameters at least include: injection molding temperature and injection molding time.

[0024] In a second aspect, an embodiment of the present application provides a pressure holding control device for an injection molding process, comprising:

[0025] A determination module, used to determine a first holding pressure for holding a first surface of a target injection molded part and a second holding pressure for holding a second surface of the target injection molded part, and determine a first holding time for holding the first surface and a second holding time for holding the second surface; a wall thickness of the first surface is less than a wall thickness of the second surface;

[0026] a first control module, configured to control the injection molding machine to perform a holding pressure operation on the first surface according to the first holding pressure and the first holding time when it is determined that the cavity of the mold for molding the target injection molded part is completely filled with the plastic melt;

[0027] The second control module is used to control the injection molding machine to perform the pressure holding operation on the second surface according to the second pressure holding pressure and the second pressure holding time after determining that the injection molding machine completes the pressure holding operation on the first surface.

[0028] In a third aspect, an embodiment of the present application provides an electronic device, comprising a memory and a processor, wherein the memory is used to store executable data instructions; when the processor is used to execute the executable data instructions stored in the memory, the steps in the pressure holding control method for the injection molding process as described in the first aspect are implemented.

[0029] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, in which a computer program is stored. When the computer program is executed by a processor, the steps in the pressure holding control method for the injection molding process as described in the first aspect are implemented.

[0030] The pressure holding control method, device, equipment and medium for the injection molding process provided in the embodiments of the present application first determine a first holding pressure for a first surface of a target injection molded part and a second holding pressure for a second surface of the target injection molded part, and determine a first holding time for the first surface and a second holding time for the second surface, wherein the wall thickness of the first surface is less than the wall thickness of the second surface, and then, when it is determined that the cavity of the mold for injection molding the target injection molded part is completely filled with the plastic melt, the injection molding machine is controlled to perform a pressure holding operation on the first surface according to the first holding pressure and the first holding time, and then, after it is determined that the injection molding machine completes the pressure holding operation on the first surface, the injection molding machine is controlled to perform a pressure holding operation on the second surface according to the second holding pressure and the second holding time, so that by setting specific holding pressures and holding times for the first surface with a smaller wall thickness and the second surface with a larger wall thickness, respectively, the material shrinkage of different wall thickness areas can be controlled in a targeted manner, thereby reducing deformation caused by shrinkage differences, helping to ensure the shape and dimensional accuracy of the target injection molded part, and improving the overall appearance quality of the target injection molded part. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0032] Figure 1 A structural schematic diagram of an automotive interior and exterior decorative part provided for related technology;

[0033] Figure 2 A schematic diagram of the wall thickness distribution of an automotive interior and exterior decorative part provided for related technology;

[0034] Figure 3 One of the flow diagrams of a pressure holding control method for an injection molding process provided in an embodiment of the present application;

[0035] Figure 4 A second flow chart of a pressure holding control method for an injection molding process provided in an embodiment of the present application;

[0036] Figure 5 A third flow chart of a pressure holding control method for an injection molding process provided in an embodiment of the present application;

[0037] Figure 6 A schematic structural diagram of a pressure holding control device for an injection molding process provided in an embodiment of the present application;

[0038] Figure 7A schematic diagram of the physical structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0040] It should be noted that in the description of the embodiments of the present application, the terms "first", "second", etc. are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of the same type, and the number of objects is not limited. For example, the first object can be one or more.

[0041] In order to facilitate a clearer understanding of the various embodiments of the present application, the structure and wall thickness distribution of automobile interior and exterior decorative parts are first briefly introduced as follows.

[0042] Figure 1 A structural schematic diagram of an automotive interior and exterior decoration part provided for related technology, such as Figure 1 As shown, the automobile interior and exterior decoration part is composed of two parts: a main surface and a flange. It should be noted that the flange can have only one side, such as a wheel eyebrow or other parts; or the flange can have multiple sides.

[0043] Figure 2 A schematic diagram of the wall thickness distribution of an automotive interior and exterior decorative part is provided for related technology, such as Figure 2 As shown in the figure, the wall thickness of the main surface is T, the wall thickness of the right flange is T1, and T1<T; the wall thickness of the left flange is T2, and T2<T. It can be seen that the wall thickness of the flange is usually smaller than the wall thickness of the main surface. Therefore, under the standard injection molding holding pressure process conditions, due to the characteristics of material cooling and shrinkage, the shrinkage of the flange area will be smaller than that of the main surface. This shrinkage difference will cause significant deformation problems of decorative parts after injection molding, thereby affecting the appearance quality of decorative parts.

[0044] In order to improve the above-mentioned defects existing in the related technology, the embodiments of the present application provide a holding pressure control method, device, equipment and medium for the injection molding process. By setting specific holding pressure and holding time for the surface with smaller wall thickness and the surface with larger wall thickness, respectively, the material shrinkage of different wall thickness areas can be controlled in a targeted manner, thereby reducing deformation caused by shrinkage differences, helping to ensure the shape and dimensional accuracy of the target injection molded parts, and improving the overall appearance quality of the target injection molded parts.

[0045] The following is an illustrative introduction to the pressure holding control method, device, equipment and medium for the injection molding process provided in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application.

[0046] Figure 3 One of the flow diagrams of a pressure holding control method for an injection molding process provided in an embodiment of the present application is shown in FIG. Figure 3 As shown, the method includes:

[0047] S301, determining a first holding pressure for holding a first surface of a target injection molded part and a second holding pressure for holding a second surface of the target injection molded part, and determining a first holding time for holding the first surface and a second holding time for holding the second surface; the wall thickness of the first surface is smaller than the wall thickness of the second surface.

[0048] It should be noted that the target injection molded part in the embodiment of the present application may be any injection molded part including structures with different wall thicknesses (wherein the structures with different wall thicknesses include a first surface and a second surface).

[0049] It should be noted that in the embodiment of the present application, the wall thickness of the first surface is smaller than the wall thickness of the second surface. The first surface can be regarded as the flange area of ​​the target injection molded part, and its wall thickness is smaller; the second surface can be regarded as the main surface area of ​​the target injection molded part, and its wall thickness is larger.

[0050] In some embodiments, the first holding pressure and the first holding time for holding the first surface, and the second holding pressure and the second holding time for holding the second surface can be determined based on the wall thickness of the first surface and the second surface and combined with the characteristics of material cooling and shrinkage.

[0051] In some embodiments, the first holding pressure and the first holding time for holding the first surface, and the second holding pressure and the second holding time for holding the second surface can be determined based on the wall thickness of the first surface and the second surface and combined with historical holding process parameters.

[0052] S302: When it is determined that the cavity of the mold for molding the target injection-molded part is completely filled with the plastic melt, control the injection molding machine to perform a holding pressure operation on the first surface according to the first holding pressure and the first holding time.

[0053] It can be understood that the cavity of the mold used for injection molding the target injection molded part is completely filled with the plastic melt, indicating that during the injection molding stage of the target injection molded part, the injection molding machine completes the injection molding short shot operation of 100% of the volume of the target injection molded part.

[0054] It should be noted that during the injection molding process, the plastic melt is injected into the mold cavity, and as the melt cools and solidifies, the injection molded part is gradually formed. In order to ensure the dimensional accuracy and appearance quality of the injection molded part, it is necessary to perform pressure holding operations at different stages after the melt fills the cavity.

[0055] In the embodiment of the present application, after determining that the mold cavity is completely filled with the plastic melt, the injection molding machine can be immediately controlled to perform a holding pressure operation on the first surface according to the first holding pressure and the first holding pressure duration. In this step, the first surface with a smaller wall thickness is intended to have a larger shrinkage with a smaller holding pressure.

[0056] S303: After determining that the injection molding machine completes the pressure-holding operation on the first surface, control the injection molding machine to perform the pressure-holding operation on the second surface according to the second pressure-holding pressure and the second pressure-holding time.

[0057] In the embodiment of the present application, after the first stage of the pressure holding operation is completed (i.e., the pressure holding operation is completed on the first surface), the injection molding machine can be immediately controlled to perform the pressure holding operation on the second surface according to the second pressure holding pressure and the second pressure holding time. In this step, the second surface with a larger wall thickness is intended to have a smaller shrinkage, so as to reduce the shrinkage difference between the first surface and the second surface, thereby reducing the deformation caused by the shrinkage difference.

[0058] It should be noted that the pressure holding control method for the injection molding process provided in the embodiment of the present application is particularly suitable for injection molded parts with different wall thickness structures. By setting specific holding pressures and holding times for surfaces with smaller wall thicknesses and surfaces with larger wall thicknesses, respectively, the material shrinkage of areas with different wall thicknesses can be controlled in a targeted manner to reduce deformation caused by shrinkage differences.

[0059] It can be understood that the holding pressure control method for the injection molding process provided in the embodiment of the present application first determines a first holding pressure for the first surface of the target injection molded part and a second holding pressure for the second surface of the target injection molded part, and determines a first holding pressure time for the first surface and a second holding pressure time for the second surface, wherein the wall thickness of the first surface is less than the wall thickness of the second surface, and then, when it is determined that the cavity of the mold used to inject the target injection molded part is completely filled with the plastic melt, the injection molding machine is controlled to perform a holding pressure operation on the first surface according to the first holding pressure and the first holding pressure time, and then after it is determined that the injection molding machine completes the holding pressure operation on the first surface, the injection molding machine is controlled to perform a holding pressure operation on the second surface according to the second holding pressure and the second holding pressure time. In this way, by setting specific holding pressures and holding pressure times for the first surface with a smaller wall thickness and the second surface with a larger wall thickness, respectively, the material shrinkage of different wall thickness areas can be controlled in a targeted manner, thereby reducing deformation caused by shrinkage differences, helping to ensure the shape and dimensional accuracy of the target injection molded part, and improving the overall appearance quality of the target injection molded part.

[0060] In some embodiments, determining a first holding pressure for holding a first surface of a target injection molded part and a second holding pressure for holding a second surface of the target injection molded part includes:

[0061] determining a maximum rated pressure of the injection molding machine;

[0062] The first holding pressure and the second holding pressure are determined based on the maximum rated pressure.

[0063] In the embodiment of the present application, the maximum rated pressure of the injection molding machine can be used as a reference to determine the first holding pressure for the first surface and the second holding pressure for the second surface. Among them, for the first surface, considering that it is more susceptible to cooling shrinkage due to its thin wall thickness, when setting the first holding pressure, it is necessary to ensure that the holding pressure can effectively compensate for material shrinkage and will not cause deformation of the injection molded part due to excessive holding pressure; for the second surface, due to its large wall thickness, its cooling shrinkage process is relatively slow, so when setting the second holding pressure, the holding pressure value can be appropriately increased to better control material shrinkage. In addition, it is necessary to ensure that the set first holding pressure and second holding pressure do not exceed the maximum rated pressure of the injection molding machine.

[0064] It can be understood that the embodiment of the present application takes the maximum rated pressure of the injection molding machine as a reference, thereby ensuring that the set first holding pressure and second holding pressure will not exceed the bearing capacity of the injection molding machine and can effectively meet the holding pressure requirements of different wall thickness areas of the injection molded part.

[0065] In some embodiments, the first holding pressure is less than a first multiple of the maximum rated pressure, the second holding pressure is within a target range, the minimum value of the target range is a second multiple of the maximum rated pressure, and the maximum value of the target range is a third multiple of the maximum rated pressure; the first multiple is less than the second multiple, and the second multiple is less than the third multiple.

[0066] It should be noted that since the wall thickness of the first surface is thinner and more susceptible to cooling shrinkage, it is necessary to ensure that the first holding pressure can effectively compensate for material shrinkage and will not cause deformation of the injection molded part due to excessive pressure. Therefore, the embodiment of the present application sets the first holding pressure to be less than the first multiple of the maximum rated pressure of the injection molding machine, and the first multiple is a smaller ratio, such as 5%, 7% or 10%.

[0067] It should be noted that, since the wall thickness of the second surface is relatively large and the cooling shrinkage process is relatively slow, the second holding pressure value can be appropriately increased to better control the material shrinkage. Therefore, the second holding pressure in the embodiment of the present application is set to a larger proportion range of the maximum rated pressure of the injection molding machine, such as 30% to 80% (equivalent to the second multiple of 30% and the third multiple of 80% in the embodiment of the present application).

[0068] It should be noted that the embodiment of the present application does not specifically limit the values ​​of the first multiple, the second multiple and the third multiple, and can be adaptively set based on actual applications. It only needs to ensure that the first multiple is smaller than the second multiple, and the second multiple is smaller than the third multiple.

[0069] In some embodiments, the first holding pressure can be set to be less than 10% of the maximum rated pressure of the injection molding machine, in order to use a smaller holding pressure to make the first surface have a larger shrinkage, and the second holding pressure can be set to 80% of the maximum rated pressure of the injection molding machine, in order to make the second surface have a smaller shrinkage, thereby reducing the deformation caused by the shrinkage difference between the first surface and the second surface.

[0070] It can be understood that the embodiment of the present application determines the value range of the first holding pressure and the second holding pressure by setting the multiple relationship between the holding pressure and the maximum rated pressure of the injection molding machine, which can provide a more precise and flexible control method for the injection molding process, and can ensure that the deformation of the first surface and the second surface caused by the shrinkage difference is reduced by flexibly setting the first holding pressure and the second holding pressure.

[0071] In some embodiments, determining a first holding time for holding pressure on the first surface and a second holding time for holding pressure on the second surface includes:

[0072] Obtaining a first time point at which the mold cavity of the mold is filled with the plastic melt in a first volume ratio and a second time point at which the mold cavity of the mold is filled with the plastic melt in a second volume ratio; the first volume ratio is smaller than the second volume ratio;

[0073] Determine, by using a mold flow analysis method, a third time point at which the freezing degree of the first surface reaches a first freezing ratio and a fourth time point at which the freezing degree of the second surface reaches a second freezing ratio; the first freezing ratio is less than the second freezing ratio;

[0074] Determine the first pressure-holding time based on the second time point and the third time point, and determine the second pressure-holding time based on the first time point and the fourth time point;

[0075] The first time point, the second time point, the third time point and the fourth time point are all measured based on the time when the injection molding machine starts to inject the plastic melt into the cavity of the mold.

[0076] It should be noted that the first time point in the embodiment of the present application is the moment when the mold cavity is filled with the plastic melt to a first volume ratio. The first volume ratio can be set to a value close to but less than 100%, such as 80%, 90% or 95%, etc., to reflect the moment when the mold cavity is about to be completely filled with the plastic melt. This time point can be obtained by the control system or sensor of the injection molding machine.

[0077] It should be noted that the second time point in the embodiment of the present application is the moment when the mold cavity is filled with the plastic melt to the second volume ratio. The second volume ratio can be set to 100%, and this time point marks the end of the filling phase and the beginning of the pressure holding phase. Similarly, this time point can also be obtained by the control system or sensor of the injection molding machine.

[0078] It should be noted that mold flow analysis is a computer simulation technology used to simulate the flow and cooling and solidification behavior of plastic melt during injection molding. Through mold flow analysis, the filling condition, temperature distribution, pressure distribution, and freezing completion of injection molded parts can be predicted.

[0079] It should be noted that the third time point in the embodiment of the present application is the moment when the freezing completion degree of the first surface reaches the first freezing ratio. The first freezing ratio can be set to a value close to but less than 100%, such as 80%, 90% or 95%, etc., to reflect the moment when the first surface is about to be completely frozen. This time point can be accurately determined through mold flow analysis.

[0080] It should be noted that the fourth time point in the embodiment of the present application is the moment when the freezing completion degree of the second surface reaches the second freezing ratio. The second freezing ratio can be set to 100% to reflect the moment when the second surface is completely frozen. Similarly, this time point can also be accurately determined by mold flow analysis.

[0081] In some embodiments, the first pressure-maintaining time length may be obtained by subtracting the second time point from the third time point.

[0082] In some embodiments, the second pressure-maintaining time length may be obtained by subtracting the first time point from the fourth time point.

[0083] It should be noted that the first time point, the second time point, the third time point and the fourth time point in the embodiment of the present application are measured based on the time when the injection molding machine starts to inject the plastic melt into the mold cavity. This reference time is the starting point of the injection molding process and is also the basis for determining the relative positions of various time points.

[0084] It should be noted that the first volume ratio and the second volume ratio in the embodiment of the present application can be adaptively set based on actual applications, and the embodiment of the present application does not make specific limitations on this, and it is only necessary to ensure that the first volume ratio is smaller than the second volume ratio. Similarly, the first freezing ratio and the second freezing ratio in the embodiment of the present application can be adaptively set based on actual applications, and the embodiment of the present application does not make specific limitations on this, and it is only necessary to ensure that the first freezing ratio is smaller than the second freezing ratio.

[0085] It is understandable that the embodiment of the present application can achieve precise control of the pressure holding operation during the injection molding process by obtaining the time points at which the mold cavity is filled with plastic melt in different volume proportions, using the mold flow analysis method to determine the time points at which the freezing completion of different surfaces reaches a specific proportion, and determining the pressure holding time based on these time points. This method helps to improve the dimensional accuracy, appearance quality and mechanical properties of injection molded parts, and provides strong support for the optimization of injection molding technology.

[0086] In some embodiments, before determining a first holding pressure for holding a first surface of a target injection molded part and a second holding pressure for holding a second surface of the target injection molded part, and determining a first holding time for holding the first surface and a second holding time for holding the second surface, the method further includes:

[0087] Controlling the injection molding machine to inject the plastic melt into the mold cavity of the mold in a manner of gradually increasing the injection amount;

[0088] When it is determined that the mold cavity is completely filled with the plastic melt, the injection molding machine is controlled to lock the injection process parameters involved in the process of the injection molding machine injecting the plastic melt into the mold cavity.

[0089] In the embodiment of the present application, before determining the holding pressure and holding time to control the injection molding machine to perform the holding pressure operation, the injection molding machine can be controlled to inject the plastic melt into the mold cavity in a manner of gradually increasing the injection amount. For example, according to the percentage of the target injection molded part volume, the injection molding machine is controlled to perform 5%, 10%, 30%, 50%, 80% and 100% injection short shot operations in sequence. Moreover, after determining that the mold cavity is completely filled with the plastic melt, the injection molding machine can be controlled to lock the injection process parameters involved in the process of injecting the plastic melt into the mold cavity.

[0090] In some embodiments, the injection molding process parameters at least include: injection molding temperature and injection molding time.

[0091] It should be noted that the injection temperature refers to the temperature at which the plastic melt is heated in the barrel of the injection molding machine and reaches suitable fluidity; the injection time refers to the time it takes to complete the injection of a specific volume ratio during the process of the injection molding machine injecting the plastic melt into the mold cavity in a gradually increasing manner.

[0092] It should be noted that, after determining that the mold cavity is completely filled with plastic melt, the embodiment of the present application controls the injection molding machine to lock the injection process parameters, which can ensure that the plastic melt in the mold cavity is completely filled and stable before the pressure holding operation begins, and can more effectively control the variables in the pressure holding process, thereby improving the controllability and accuracy of the pressure holding operation. Moreover, the combination of a stable filling state and a controllable pressure holding process helps to obtain higher quality injection molded parts.

[0093] For example, Figure 4 The second flow chart of a pressure holding control method for an injection molding process provided in an embodiment of the present application is as follows: Figure 4 As shown, the method includes:

[0094] S401, controlling the injection molding machine to inject plastic melt into a mold cavity of a mold for molding a target injection molded part in a manner of gradually increasing the injection amount.

[0095] S402: When it is determined that the mold cavity is completely filled with the plastic melt, control the injection molding machine to lock injection process parameters involved in the process of the injection molding machine injecting the plastic melt into the mold cavity.

[0096] S403, determining a first holding pressure for holding the first surface of the target injection molded part and a second holding pressure for holding the second surface of the target injection molded part, and determining a first holding time for holding the first surface and a second holding time for holding the second surface; the wall thickness of the first surface is less than the wall thickness of the second surface.

[0097] S404: When it is determined that the cavity of the mold is completely filled with the plastic melt, control the injection molding machine to perform a holding pressure operation on the first surface according to the first holding pressure and the first holding time.

[0098] S405 . After determining that the injection molding machine completes the pressure-holding operation on the first surface, control the injection molding machine to perform the pressure-holding operation on the second surface according to the second pressure-holding pressure and the second pressure-holding time.

[0099] It should be noted that, for the description of the same steps and the same contents in this embodiment as those in other embodiments, reference can be made to the description in other embodiments and will not be repeated here.

[0100] It can be understood that the embodiment of the present application provides a more stable and controllable premise for subsequent differentiated pressure holding operations by gradually increasing the injection volume and locking the injection process parameters, which helps to improve the dimensional stability and surface quality of the injection molded parts.

[0101] In some embodiments, before controlling the injection molding machine to inject the plastic melt into the mold cavity of the mold in a manner of gradually increasing the injection amount, the method further includes:

[0102] The temperature control device is instructed to control the temperature of the mold within a first set temperature range, and to control the temperature of the plastic melt within a second set temperature range.

[0103] It should be noted that mold temperature is a key factor affecting the cooling rate of injection molded parts. Appropriate mold temperature helps the plastic melt to cool evenly in the mold cavity, thereby avoiding problems such as excessive internal stress, uneven shrinkage or deformation of the injection molded parts. Mold temperature also affects the surface quality of the injection molded parts. High-temperature molds can accelerate the flow of plastic melt, which is conducive to filling complex cavities, but may also cause defects such as weld lines and flow marks on the surface of injection molded parts; while low-temperature molds help to obtain better surface finish, but may increase the cooling time of injection molded parts.

[0104] It should be noted that the first set temperature range can be determined based on a comprehensive consideration of factors such as the thermal properties of the plastic material, the mold material, the size and shape of the injection molded part, and production requirements, and the embodiments of the present application do not specifically limit this.

[0105] It should be noted that the temperature of the plastic melt directly affects its fluidity and viscosity. Appropriate plastic melt temperature helps the plastic melt to smoothly fill the mold cavity and reduce energy consumption during the injection molding process. Too high a plastic melt temperature may cause the plastic material to decompose, burn, or produce harmful gases, thereby affecting the performance and appearance of the injection molded parts; while too low a plastic melt temperature may increase the injection pressure, reduce the filling efficiency, and even cause insufficient filling.

[0106] It should be noted that the second set temperature range can be determined based on a comprehensive consideration of factors such as the thermal properties of the plastic material, the heating capacity of the injection molding machine, the mold temperature, and production requirements, and the embodiments of the present application do not specifically limit this.

[0107] It should be noted that the temperature control equipment is a device that can control the temperature of the mold and the temperature of the plastic melt.

[0108] In some embodiments, the barrel heater of the injection molding machine can be used to heat the plastic material, and the temperature of the plastic melt can be monitored in real time through a temperature sensor. According to the feedback signal of the temperature sensor, the control system of the injection molding machine can automatically adjust the power of the barrel heater to ensure that the melt temperature is always maintained within a set temperature range.

[0109] It can be understood that the embodiments of the present application can significantly improve the quality and production efficiency of injection molded parts by accurately controlling the temperature of the mold and the temperature of the plastic melt.

[0110] For example, Figure 5 The third flow chart of a pressure holding control method for an injection molding process provided in an embodiment of the present application is as follows: Figure 5 As shown, the method includes:

[0111] S501, controlling various parameters in the injection molding process (such as plastic melt temperature and mold temperature) within a preset value range.

[0112] S502, according to the percentage of the target injection molded part volume, perform injection molding short shot operations of 5%, 10%, 30%, 50%, 80% and 100% in sequence.

[0113] S503, after completing 100% of the injection short shot operation, immediately enter the holding stage; set the first holding pressure to be 10% lower than the maximum rated pressure of the injection molding machine, and the first holding time is the time for the flanging to complete freezing of 90% to 100% minus the time for injection molding to complete 100% of the volume; set the second holding pressure to be between 30% and 80% of the maximum rated pressure of the injection molding machine, and the second holding time is the time for the main surface to complete freezing of 100% minus the time for injection molding to complete 90% to 100% of the volume.

[0114] S504, performing a holding operation according to the set holding pressure and holding time.

[0115] It is understandable that the embodiment of the present application controls the deformation of the target injection molded part within a reasonable range by adopting a pressure holding process during the injection molding process. Specifically, since the surface with a smaller wall thickness freezes before the surface with a larger wall thickness during the injection molding process, the sequential freezing can be used to make the surface that freezes first shrink more and the surface that freezes later shrink less during the pressure holding process, thereby reducing the shrinkage difference between the two and reducing the deformation of the injection molded part. In addition, the embodiment of the present application can also bring at least the following beneficial effects:

[0116] (1) It makes the wall thickness design range of injection molded parts wider, thereby widening the limitations of injection molded part modeling and design; (2) It can shorten the rectification cycle of injection molded part deformation, thereby reducing costs and shortening the development cycle of injection molded parts.

[0117] The following is a description of a pressure-holding control device for an injection molding process provided in an embodiment of the present application. The pressure-holding control device for an injection molding process described below and the pressure-holding control method for an injection molding process described above can be referred to each other.

[0118] Figure 6 A schematic diagram of a pressure holding control device for an injection molding process provided in an embodiment of the present application is shown in FIG. Figure 6 As shown, the device includes: a determination module 610, a first control module 620 and a second control module 630; wherein:

[0119] A determination module 610 is used to determine a first holding pressure for holding a first surface of a target injection molded part and a second holding pressure for holding a second surface of the target injection molded part, and to determine a first holding time for holding the first surface and a second holding time for holding the second surface; a wall thickness of the first surface is less than a wall thickness of the second surface;

[0120] A first control module 620 is used to control the injection molding machine to perform a holding pressure operation on the first surface according to the first holding pressure and the first holding time when it is determined that the cavity of the mold for molding the target injection molded part is completely filled with plastic melt;

[0121] The second control module 630 is used to control the injection molding machine to perform the pressure holding operation on the second surface according to the second pressure holding pressure and the second pressure holding time after determining that the injection molding machine completes the pressure holding operation on the first surface.

[0122] The pressure holding control device for the injection molding process provided in the embodiment of the present application first determines a first holding pressure for a first surface of a target injection molded part and a second holding pressure for a second surface of the target injection molded part, and determines a first holding time for the first surface and a second holding time for the second surface, wherein the wall thickness of the first surface is less than the wall thickness of the second surface, and then, when it is determined that the cavity of the mold for injection molding the target injection molded part is completely filled with the plastic melt, controls the injection molding machine to perform a pressure holding operation on the first surface according to the first holding pressure and the first holding time, and then, after it is determined that the injection molding machine completes the pressure holding operation on the first surface, controls the injection molding machine to perform a pressure holding operation on the second surface according to the second holding pressure and the second holding time, so that, by setting specific holding pressures and holding times for the first surface with a smaller wall thickness and the second surface with a larger wall thickness, respectively, the material shrinkage of different wall thickness areas can be controlled in a targeted manner, thereby reducing deformation caused by shrinkage differences, helping to ensure the shape and dimensional accuracy of the target injection molded part, and improving the overall appearance quality of the target injection molded part.

[0123] In some embodiments, the determining module 610 includes:

[0124] A first determining unit, used to determine the maximum rated pressure of the injection molding machine;

[0125] The second determining unit is configured to determine the first holding pressure and the second holding pressure based on the maximum rated pressure.

[0126] In some embodiments, the first holding pressure is less than a first multiple of the maximum rated pressure, the second holding pressure is within a target range, the minimum value of the target range is a second multiple of the maximum rated pressure, and the maximum value of the target range is a third multiple of the maximum rated pressure; the first multiple is less than the second multiple, and the second multiple is less than the third multiple.

[0127] In some embodiments, the determining module 610 further includes:

[0128] an acquisition unit, configured to acquire a first time point at which the mold cavity of the mold is filled with the plastic melt in a first volume ratio and a second time point at which the mold cavity of the mold is filled with the plastic melt in a second volume ratio; the first volume ratio is smaller than the second volume ratio;

[0129] A third determining unit is used to determine, by using a mold flow analysis method, a third time point at which the freezing completion degree of the first surface reaches a first freezing ratio and a fourth time point at which the freezing completion degree of the second surface reaches a second freezing ratio; the first freezing ratio is less than the second freezing ratio;

[0130] a fourth determining unit, configured to determine the first pressure-holding time based on the second time point and the third time point, and to determine the second pressure-holding time based on the first time point and the fourth time point;

[0131] The first time point, the second time point, the third time point and the fourth time point are all measured based on the time when the injection molding machine starts to inject the plastic melt into the cavity of the mold.

[0132] In some embodiments, the apparatus further comprises:

[0133] A third control module is used to control the injection molding machine to inject the plastic melt into the mold cavity of the mold in a manner of gradually increasing the injection amount;

[0134] The fourth control module is used to control the injection molding machine to lock the injection process parameters involved in the process of the injection molding machine injecting the plastic melt into the mold cavity when it is determined that the mold cavity of the mold is completely filled with the plastic melt.

[0135] In some embodiments, the apparatus further comprises:

[0136] The indicating module is used to instruct the temperature control device to control the temperature of the mold within a first set temperature range and to control the temperature of the plastic melt within a second set temperature range.

[0137] In some embodiments, the injection molding process parameters at least include: injection molding temperature and injection molding time.

[0138] It should be noted here that the above-mentioned pressure-holding control device for the injection molding process provided in the embodiment of the present application can implement all the method steps implemented in the above-mentioned pressure-holding control method embodiment for the injection molding process, and can achieve the same technical effect. The parts and beneficial effects of this embodiment that are the same as those of the method embodiment will not be described in detail here.

[0139] Figure 7 A schematic diagram of the physical structure of an electronic device provided in an embodiment of the present application, such as Figure 7 As shown, the electronic device may include: a processor 710, a communication interface 720, a memory 730 and a communication bus 740, wherein the processor 710, the communication interface 720 and the memory 730 communicate with each other through the communication bus 740. The processor 710 may execute the executable data instructions stored in the memory 730 to implement part or all of the steps in the pressure holding control method for the injection molding process provided in the above embodiments.

[0140] In addition, the executable data instructions stored in the above-mentioned memory 730 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on this understanding, the technical solution of the embodiment of the present application can be essentially or partly reflected in the form of a software product that contributes to the relevant technology. The software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read Only Memory, ROM), random access memory (Random Access Memory, RAM), disk or optical disk and other media that can store program code.

[0141] An embodiment of the present application also provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, some or all of the steps in the pressure holding control method for the injection molding process provided in the above embodiments are implemented.

[0142] An embodiment of the present application also provides a computer program product, which includes a computer program or instructions. When the computer program or instructions are executed by a processor, some or all of the steps in the pressure holding control method for the injection molding process provided in the above embodiments are implemented.

[0143] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Those of ordinary skill in the art may understand and implement it without creative work.

[0144] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the embodiments of the present application may adopt the form of hardware embodiments, software embodiments, or embodiments in combination with software and hardware. Moreover, the embodiments of the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) that contain computer-usable program code.

[0145] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0146] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0147] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0148] The above description is merely an optional embodiment of the present application and is not intended to limit the protection scope of the present application.

Claims

1. A pressure holding control method for an injection molding process, characterized in that: include: Determining a first holding pressure for holding a first surface of a target injection molded part and a second holding pressure for holding a second surface of the target injection molded part, and determining a first holding time for holding the first surface and a second holding time for holding the second surface; The wall thickness of the first surface is smaller than the wall thickness of the second surface; When it is determined that the cavity of the mold for molding the target injection molded part is completely filled with the plastic melt, controlling the injection molding machine to perform a holding pressure operation on the first surface according to the first holding pressure and the first holding pressure duration; After determining that the injection molding machine completes the pressure holding operation on the first surface, controlling the injection molding machine to perform the pressure holding operation on the second surface according to the second pressure holding pressure and the second pressure holding time.

2. The pressure holding control method for injection molding process according to claim 1, characterized in that: The determining of a first holding pressure for holding a first surface of a target injection molded part and a second holding pressure for holding a second surface of the target injection molded part comprises: determining a maximum rated pressure of the injection molding machine; The first holding pressure and the second holding pressure are determined based on the maximum rated pressure.

3. The pressure holding control method for injection molding process according to claim 2, characterized in that: The first holding pressure is less than a first multiple of the maximum rated pressure, the second holding pressure is within a target range, the minimum value of the target range is a second multiple of the maximum rated pressure, and the maximum value of the target range is a third multiple of the maximum rated pressure; The first multiple is smaller than the second multiple, and the second multiple is smaller than the third multiple.

4. The method for controlling the holding pressure of an injection molding process according to claim 1, characterized in that: The determining of a first holding time for holding pressure on the first surface and a second holding time for holding pressure on the second surface includes: Obtaining a first time point at which the mold cavity of the mold is filled with the plastic melt in a first volume ratio and a second time point at which the mold cavity of the mold is filled with the plastic melt in a second volume ratio; the first volume ratio is smaller than the second volume ratio; Determine, by using a mold flow analysis method, a third time point at which the freezing degree of the first surface reaches a first freezing ratio and a fourth time point at which the freezing degree of the second surface reaches a second freezing ratio; the first freezing ratio is less than the second freezing ratio; Determine the first pressure-holding time based on the second time point and the third time point, and determine the second pressure-holding time based on the first time point and the fourth time point; The first time point, the second time point, the third time point and the fourth time point are all measured based on the time when the injection molding machine starts to inject the plastic melt into the cavity of the mold.

5. The method for controlling the holding pressure in an injection molding process according to any one of claims 1 to 4, characterized in that: Before determining a first holding pressure for holding pressure on a first surface of a target injection molded part and a second holding pressure for holding pressure on a second surface of the target injection molded part, and determining a first holding time for holding pressure on the first surface and a second holding time for holding pressure on the second surface, the method further includes: Controlling the injection molding machine to inject the plastic melt into the mold cavity of the mold in a manner of gradually increasing the injection amount; When it is determined that the mold cavity is completely filled with the plastic melt, the injection molding machine is controlled to lock the injection process parameters involved in the process of the injection molding machine injecting the plastic melt into the mold cavity.

6. The method for controlling the holding pressure in an injection molding process according to claim 5, characterized in that: Before controlling the injection molding machine to inject the plastic melt into the mold cavity of the mold in a manner of gradually increasing the injection amount, the method further includes: The temperature control device is instructed to control the temperature of the mold within a first set temperature range, and to control the temperature of the plastic melt within a second set temperature range.

7. The method for controlling the holding pressure in an injection molding process according to claim 5, characterized in that: The injection molding process parameters at least include: injection molding temperature and injection molding time.

8. A pressure holding control device for an injection molding process, characterized in that: include: A determination module, used to determine a first holding pressure for holding pressure on a first surface of a target injection molded part and a second holding pressure for holding pressure on a second surface of the target injection molded part, and to determine a first holding time for holding pressure on the first surface and a second holding time for holding pressure on the second surface; The wall thickness of the first surface is smaller than the wall thickness of the second surface; a first control module, configured to control the injection molding machine to perform a holding pressure operation on the first surface according to the first holding pressure and the first holding time when it is determined that the cavity of the mold for molding the target injection molded part is completely filled with the plastic melt; The second control module is used to control the injection molding machine to perform the pressure holding operation on the second surface according to the second pressure holding pressure and the second pressure holding time after determining that the injection molding machine completes the pressure holding operation on the first surface.

9. An electronic device, characterized in that: include: A memory for storing executable data instructions; The processor is used to implement the steps of the pressure holding control method for the injection molding process as described in any one of claims 1 to 7 when executing the executable data instructions stored in the memory.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the pressure holding control method for an injection molding process according to any one of claims 1 to 7 are implemented.

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