Intelligent compression molding method for a circuit breaker housing

Abstract

The application relates to the technical field of circuit breakers, in particular to an intelligent mold pressing forming method for a circuit breaker shell, which comprises the following steps: adding plastic raw materials into an injection molding machine to output molten plastic raw materials, closing upper and lower molds to form a mold, and injecting the molten plastic raw materials into the mold; after pressure maintaining and cooling operations are sequentially performed on the mold, the mold is opened to output a semi-finished shell, the semi-finished shell is surface finished to output the circuit breaker shell; if the mold pressing forming stability does not meet the requirements, it is determined whether the heating power of the mold is increased; whether the operation stability of the mold meets the requirements is determined based on the position deviation amount of the upper and lower molds in the mold; if the operation stability does not meet the requirements, it is determined whether the output flow of a mold oil pump is increased; whether the no-load operation time of a hydraulic pump in the injection molding machine is increased is determined based on the fluctuation amplitude of injection molding pressure. The mold pressing forming stability of the circuit breaker shell is improved.

Description

Technical Field

[0001] This invention relates to the field of circuit breaker technology, and in particular to an intelligent molding method for circuit breaker housings. Background Technology

[0002] In modern power systems, circuit breakers are crucial devices for ensuring the safe operation of circuits, and their performance and quality are of paramount importance. The circuit breaker housing, as a key component protecting internal electrical components, is subject to stringent requirements regarding its manufacturing quality.

[0003] Traditional compression molding methods for circuit breaker housings have many drawbacks. During the molding process, it is difficult to precisely control the mold temperature, resulting in uneven temperature distribution. This not only affects the fluidity and curing effect of the plastic raw material, leading to internal stress concentration, poor dimensional accuracy, and poor surface quality, but may also cause unstable product performance. In the long term, cracking and deformation are likely to occur, reducing the reliability and service life of the circuit breaker.

[0004] Chinese Patent Publication No. CN115101385A discloses a circuit breaker housing processing system, including an injection molding machine, a welding machine, a three-axis robot, and a controller. The injection molding machine includes a hopper, a hot melt barrel, and an injection mold. The barrel is equipped with a material suction machine and a dryer. The injection mold includes two cavities, one for forming a side housing and the other for forming a middle housing. The welding machine welds the formed side housing and middle housing together. The three-axis robot, under the control of the controller, transfers the formed side housing and middle housing from the injection mold to the welding machine. However, this circuit breaker housing processing system suffers from quality problems such as flash, shrinkage marks, and dimensional deviations in the formed housing due to the possibility that the cavities used for forming the side housing and middle housing may not close completely. Summary of the Invention

[0005] Therefore, the present invention provides an intelligent molding method for circuit breaker housings to overcome the quality problems such as flash, shrinkage marks, and dimensional deviations in the molded housings caused by the fact that the mold cavities used for molding the side housings and the middle housings are prone to not being fully closed.

[0006] To achieve the above objectives, the present invention provides a smart molding method for circuit breaker housings, comprising:

[0007] Plastic raw materials are added to the injection molding machine to output molten plastic raw materials, the upper and lower molds are closed to form a mold, and the molten plastic raw materials are injected into the mold.

[0008] After performing pressure holding and cooling operations on the mold in sequence, the mold is opened to output a semi-finished housing, and the surface of the semi-finished housing is trimmed to output a circuit breaker housing.

[0009] Obtain the temperature at different locations during mold closing and calculate the maximum temperature difference during mold closing;

[0010] The molding stability of the circuit breaker housing is determined based on the maximum temperature difference between the molds.

[0011] If the molding stability does not meet the requirements, determine whether to increase the heating power of the mold;

[0012] If it is not necessary to increase the heating power of the mold, the operational stability of the mold is determined based on the positional deviation of the upper and lower molds during mold closing.

[0013] If the operational stability does not meet the requirements, determine whether to increase the output flow rate of the mold clamping oil pump;

[0014] If it is not necessary to increase the output flow rate of the clamping oil pump, then determine whether to increase the no-load running time of the hydraulic pump in the injection molding machine based on the fluctuation range of the injection pressure.

[0015] Further, determining the molding stability of the circuit breaker housing includes:

[0016] Compare the maximum temperature difference during mold closing with the preset first difference amount;

[0017] If the maximum temperature difference of the mold is less than or equal to the preset first difference, then the molding stability of the circuit breaker housing is determined to meet the requirements.

[0018] If the maximum temperature difference during mold closing exceeds the preset first difference, then the molding stability of the circuit breaker housing is determined to be non-compliant, and the reasons for non-compliance are determined, including:

[0019] The mold's operational stability does not meet the requirements, or the mold's heating power does not meet the requirements.

[0020] Furthermore, the process of determining whether the cause is due to the mold's operational stability not meeting requirements includes:

[0021] The maximum temperature difference in the mold closing process is compared with a preset second difference.

[0022] If the maximum temperature difference during mold closing is greater than the preset first difference and less than or equal to the preset second difference, it is preliminarily determined that the mold's operational stability does not meet the requirements, and the operational stability of the mold is determined based on the positional deviation of the upper and lower molds during mold closing.

[0023] Furthermore, the process of determining whether the cause is that the heating power of the mold does not meet the requirements includes:

[0024] Compare the maximum temperature difference of the mold closing with the preset second difference amount;

[0025] If the maximum temperature difference of the mold closing is greater than the preset second difference, the heating power of the mold is increased.

[0026] Furthermore, the increase in the heating power of the mold and the maximum temperature difference when the mold is closed are proportional to the difference between the preset second difference.

[0027] Furthermore, the stability of the mold's operation is determined based on the positional deviation between the upper and lower molds during mold closing, including:

[0028] The positional deviations of the upper and lower molds during mold closing are compared with the preset first deviation and the preset second deviation, respectively.

[0029] If the positional deviation of the upper and lower molds in the mold closing process is less than or equal to the preset first deviation, then it is determined that the mold's operational stability meets the requirements, while the molding stability of the circuit breaker housing does not meet the requirements, and it is determined whether the mold's heating power meets the requirements.

[0030] If the positional deviation of the upper and lower molds during mold closing is greater than the preset first deviation, then the operational stability of the mold is determined to be non-compliant, and the reasons for non-compliance are determined, including:

[0031] The output flow rate of the mold clamping oil pump does not meet the requirements, or the effectiveness of injection molding control does not meet the requirements;

[0032] If the positional deviation of the upper and lower molds during mold closing is greater than the preset first deviation and less than or equal to the preset second deviation, then increase the output flow rate of the mold closing oil pump.

[0033] If the positional deviation of the upper and lower molds during mold closing is greater than the preset second deviation, it is preliminarily determined that the control effectiveness of injection molding does not meet the requirements, and the control effectiveness of injection molding is determined based on the fluctuation range of injection pressure.

[0034] Furthermore, the increase in the output flow rate of the mold closing oil pump is proportional to the difference between the positional deviation of the upper and lower molds during mold closing and the preset first deviation.

[0035] Furthermore, the process of determining whether the control effectiveness of injection molding meets the requirements based on the fluctuation range of the injection pressure includes:

[0036] Compare the fluctuation range of the injection pressure with the preset fluctuation range;

[0037] If the fluctuation range of the injection pressure is less than or equal to the preset fluctuation range, it is determined that the control effectiveness of injection meets the requirements, but the operation stability of the mold does not meet the requirements, and it is determined whether the output flow rate of the mold clamping oil pump meets the requirements.

[0038] If the fluctuation range of the injection pressure is greater than the preset fluctuation range, it is determined that the control effectiveness of the injection molding does not meet the requirements, and the no-load running time of the hydraulic pump in the injection molding machine is increased.

[0039] Furthermore, the fluctuation range of the injection pressure is the difference between the maximum and minimum injection pressure within a single cycle.

[0040] Furthermore, the increase in the idle running time of the hydraulic pump in the injection molding machine and the fluctuation range of the injection pressure are proportional to the difference between the preset fluctuation range and the preset fluctuation range.

[0041] Compared with the prior art, the beneficial effects of the present invention are as follows: The method of the present invention adjusts the heating power of the mold according to the maximum temperature difference during mold closing. Due to the long-term operation in a high-temperature, high-pressure molding environment, the temperature sensor may age and its performance gradually declines, resulting in inaccurate temperature measurements. By increasing the heating power of the mold, the underestimation caused by the sensor can be compensated for, balancing the differences in heat conduction efficiency in different areas of the mold and reducing the heating time. The output flow rate of the mold closing oil pump is adjusted according to the positional deviation of the upper and lower molds during mold closing. After prolonged use, the sealing ring in the mold closing cylinder ages and deforms, leading to increased leakage within the cylinder and insufficient mold closing force. This is addressed by increasing the output flow rate of the mold closing oil pump. The pump's output flow rate can accelerate the oil replenishment speed, shorten the pressure replenishment time, and avoid insufficient mold closing force due to pressure recovery lag, thereby maintaining stable pressure in the cylinder. The no-load running time of the hydraulic pump in the injection molding machine can be adjusted according to the fluctuation range of the injection pressure. Since impurities in the hydraulic oil may enter the gap between the valve core and the valve sleeve of the hydraulic valve, hindering the normal movement of the valve core and causing it to jam, resulting in a drop in injection pressure, by increasing the no-load running time of the hydraulic pump in the injection molding machine, the flushing effect of the oil flow can be used to carry out the tiny impurities in the gap between the valve core and the valve sleeve, improve the valve core's movement ability, alleviate the pressure drop caused by jamming, improve the stability of injection pressure, and improve the molding stability of the circuit breaker housing.

[0042] Furthermore, the method of the present invention adjusts the heating power of the mold by setting a preset first difference amount and a preset second difference amount. Due to the long-term high temperature and high pressure molding environment, the temperature sensor may age and its performance gradually declines, resulting in inaccurate temperature values. By increasing the heating power of the mold, the underestimation caused by the sensor can be compensated for, the difference in heat conduction efficiency in different areas of the mold can be balanced, the heating time can be reduced, and the molding stability of the circuit breaker housing can be further improved.

[0043] Furthermore, the method of the present invention adjusts the output flow rate of the mold closing oil pump by setting a preset first deviation amount and a preset second deviation amount. After long-term use, the sealing ring in the mold closing cylinder ages and deforms, resulting in increased leakage in the cylinder and insufficient mold closing force. By increasing the output flow rate of the mold closing oil pump, the oil replenishment speed can be accelerated, the pressure replenishment time can be shortened, and insufficient mold closing force can be avoided due to pressure recovery lag, thereby maintaining the pressure stability in the cylinder and further improving the molding stability of the circuit breaker housing.

[0044] Furthermore, the method of the present invention adjusts the no-load running time of the hydraulic pump in the injection molding machine by setting a preset fluctuation range. Since impurities in the hydraulic oil may enter the gap between the valve core and the valve sleeve of the hydraulic valve, hindering the normal movement of the valve core and causing it to jam, resulting in a drop in injection pressure, by increasing the no-load running time of the hydraulic pump in the injection molding machine, the flushing effect of the oil flow can be used to carry out the tiny impurities in the gap between the valve core and the valve sleeve, improve the valve core's mobility, alleviate the pressure drop caused by jamming, improve the stability of injection pressure, and further improve the molding stability of the circuit breaker housing. Attached Figure Description

[0045] Figure 1 This is an overall flowchart of the intelligent molding method for circuit breaker housing according to an embodiment of the present invention;

[0046] Figure 2 This is a flowchart illustrating the process of determining whether the cause of failure in the intelligent molding method for circuit breaker housings according to an embodiment of the present invention is that the heating power of the mold does not meet the requirements.

[0047] Figure 3 This is a flowchart illustrating the process of determining whether the operational stability of the mold meets the requirements based on the positional deviation of the upper and lower molds during mold closing in an intelligent molding method for circuit breaker housings according to an embodiment of the present invention.

[0048] Figure 4 This is a flowchart illustrating the process of determining whether the control effectiveness of injection molding based on the fluctuation range of injection pressure meets the requirements in the intelligent molding method for circuit breaker housings according to an embodiment of the present invention. Detailed Implementation

[0049] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0050] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0051] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0052] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0053] Please see Figure 1 , Figure 2 , Figure 3 as well as Figure 4 The diagrams shown are, respectively, an overall flowchart of the intelligent molding method for circuit breaker housings according to an embodiment of the present invention; a logical flowchart for determining whether the cause is insufficient heating power of the mold; a logical flowchart for determining whether the operational stability of the mold meets requirements based on the positional deviation of the upper and lower molds during mold closing; and a logical flowchart for determining whether the control effectiveness of injection molding meets requirements based on the fluctuation range of injection pressure. The present invention provides an intelligent molding method for circuit breaker housings, comprising:

[0054] Step S1: Add plastic raw material into the injection molding machine to output molten plastic raw material, close the upper and lower molds to form a mold, and inject the molten plastic raw material into the mold.

[0055] Step S2: After performing pressure holding and cooling operations on the mold in sequence, the mold is opened to output the semi-finished housing, and the surface of the semi-finished housing is trimmed to output the circuit breaker housing.

[0056] Step S3: Obtain the temperature at different locations of the mold closing position and calculate the maximum temperature difference during mold closing.

[0057] Step S4: Determine whether the molding stability of the circuit breaker housing meets the requirements based on the maximum temperature difference of the mold closing.

[0058] Step S5: If the molding stability does not meet the requirements, determine whether to increase the heating power of the mold.

[0059] Step S6: If it is not necessary to increase the heating power of the mold, then determine whether the operating stability of the mold meets the requirements based on the positional deviation of the upper and lower molds during mold closing.

[0060] Step S7: If the operational stability does not meet the requirements, determine whether to increase the output flow rate of the mold clamping oil pump;

[0061] Step S8: If it is not necessary to increase the output flow rate of the mold clamping oil pump, determine whether to increase the no-load running time of the hydraulic pump in the injection molding machine based on the fluctuation range of the injection pressure.

[0062] Specifically, plastic raw materials include polycarbonate, acrylonitrile-butadiene-styrene copolymer, and polybutylene terephthalate.

[0063] Specifically, the holding pressure is generally 50 to 200 MPa, the holding time is generally 10 to 30 seconds, and the cooling time is generally 20 to 60 seconds.

[0064] Specifically, surface finishing includes deburring, surface polishing, repairing defects, and cleaning.

[0065] In practice, the method of this invention adjusts the heating power of the mold based on the maximum temperature difference during mold closing. Due to the long-term operation in a high-temperature, high-pressure molding environment, the temperature sensor may age and its performance gradually declines, leading to inaccurate temperature measurements. Increasing the heating power of the mold can compensate for insufficient heating caused by sensor underestimation, balance the differences in heat conduction efficiency across different areas of the mold, and reduce the heating time. The output flow rate of the mold closing oil pump is adjusted based on the positional deviation of the upper and lower molds during mold closing. After prolonged use, the sealing rings in the mold closing cylinder age and deform, leading to increased internal leakage and insufficient closing force. Increasing the output flow rate of the mold closing oil pump addresses this issue. It can accelerate the oil replenishment speed, shorten the pressure replenishment time, and avoid insufficient mold closing force due to pressure recovery lag, thereby maintaining stable pressure in the oil cylinder. The no-load running time of the hydraulic pump in the injection molding machine can be adjusted according to the fluctuation range of the injection pressure. Since impurities in the hydraulic oil may enter the gap between the valve core and the valve sleeve of the hydraulic valve, hindering the normal movement of the valve core and causing it to jam, resulting in a drop in injection pressure, by increasing the no-load running time of the hydraulic pump in the injection molding machine, the flushing effect of the oil flow can be used to carry out the tiny impurities in the gap between the valve core and the valve sleeve, improve the valve core's movement ability, alleviate the pressure drop caused by jamming, improve the stability of injection pressure, and improve the molding stability of the circuit breaker housing.

[0066] Specifically, determining the molding stability of the circuit breaker housing includes:

[0067] The temperature at different locations of the mold is obtained, and the maximum temperature difference during mold closing is calculated.

[0068] The maximum temperature difference in the mold closing process is compared with a preset first difference.

[0069] If the maximum temperature difference of the mold is less than or equal to the preset first difference, then the molding stability of the circuit breaker housing is determined to meet the requirements.

[0070] If the maximum temperature difference during mold closing exceeds the preset first difference, then the molding stability of the circuit breaker housing is determined to be non-compliant, and the reasons for non-compliance are determined, including:

[0071] The mold's operational stability does not meet the requirements, or the mold's heating power does not meet the requirements.

[0072] Specifically, the process of determining whether the cause is due to the mold's operational stability not meeting requirements includes:

[0073] The maximum temperature difference in the mold closing process is compared with a preset second difference.

[0074] If the maximum temperature difference during mold closing is greater than the preset first difference and less than or equal to the preset second difference, it is preliminarily determined that the mold's operational stability does not meet the requirements, and the operational stability of the mold is determined based on the positional deviation of the upper and lower molds during mold closing.

[0075] It is understandable that the three intervals divided by the preset first difference value and the preset second difference value correspond to three different situations:

[0076] The first interval is when the maximum temperature difference between the molds is less than or equal to the preset first difference, which corresponds to the situation where the molding stability of the circuit breaker housing meets the requirements.

[0077] The second range is when the maximum temperature difference during mold closing is greater than the preset first difference and less than or equal to the preset second difference. The corresponding situation is: after long-term use, the sealing ring in the mold closing cylinder ages and deforms, resulting in increased leakage inside the cylinder and insufficient mold closing force.

[0078] The third interval is when the maximum temperature difference during mold closing is greater than the preset second difference. The corresponding situation is that the temperature sensor may age due to long-term exposure to high temperature and high pressure molding environment, and its performance will gradually decline, resulting in inaccurate temperature values.

[0079] It is understandable that the preset first and second differential values ​​can be set according to actual operating conditions. The preset first and second differential values ​​are designed to improve the stability and practicality of the circuit breaker housing molding process. Optionally, the preset first and second differential values ​​are determined through a limited number of tests by evaluating the molding effect of different temperatures on the circuit breaker housing. The determined first and second differential values ​​should be detectable without causing excessive interference to the mold closing operation. For example, the preset first differential value is generally selected within the range of [3℃, 7℃], and the preset second differential value is generally selected within the range of [8℃, 12℃].

[0080] Preferably, the first differential amount is 5°C in a preferred embodiment, and the second differential amount is 10°C in a preferred embodiment.

[0081] Specifically, the maximum temperature difference during mold closing is the difference between the maximum and minimum temperatures during mold closing.

[0082] Specifically, the process of obtaining the temperature at different locations of the mold is as follows: the surface of the mold is divided into several regions of equal area, and a temperature sensor is installed at the center point of each region. The value detected by the temperature sensor is the temperature of that region.

[0083] In practice, the method of the present invention determines the molding stability of the circuit breaker housing by setting a preset first difference amount and a preset second difference amount, thereby reducing the impact of the decrease in molding accuracy of the circuit breaker housing due to inaccurate determination of the molding stability of the circuit breaker housing, and further improving the molding stability of the circuit breaker housing.

[0084] Specifically, the process of determining whether the cause is that the heating power of the mold does not meet the requirements includes:

[0085] Compare the maximum temperature difference of the mold closing with the preset second difference amount;

[0086] If the maximum temperature difference of the mold closing is greater than the preset second difference, the heating power of the mold is increased.

[0087] Specifically, the increase in the heating power of the mold and the maximum temperature difference when the mold is closed are proportional to the difference between the preset second difference.

[0088] Specifically, when the difference between the maximum temperature difference during mold closing and the preset second difference is within 2℃, the heating power of the mold is increased to 1.1 times the original value. When the difference between the maximum temperature difference during mold closing and the preset second difference exceeds 2℃, in addition to increasing to 1.1 times the original value, the heating power of the mold increases by 1kW for every 1℃ increase. For example, if the difference between the maximum temperature difference during mold closing and the preset second difference is 4℃, and the current heating power of the mold is 10kW, the increased heating power of the mold will be 10×1.1+1×2=13kW.

[0089] In practice, the method of the present invention adjusts the heating power of the mold by setting a preset first difference amount and a preset second difference amount. Due to the long-term high temperature and high pressure molding environment, the temperature sensor may age and its performance gradually declines, resulting in inaccurate temperature values. By increasing the heating power of the mold, the underestimation caused by the sensor can be compensated for, the difference in heat conduction efficiency in different areas of the mold can be balanced, the heating time can be reduced, and the molding stability of the circuit breaker housing can be further improved.

[0090] Specifically, the stability of the mold's operation is determined based on the positional deviation between the upper and lower molds during mold closing, including:

[0091] The positional deviations of the upper and lower molds during mold closing are compared with the preset first deviation and the preset second deviation, respectively.

[0092] If the positional deviation of the upper and lower molds during the mold closing process is less than or equal to the preset first deviation, then it is determined that the mold's operational stability meets the requirements, while the molding stability of the circuit breaker housing does not meet the requirements, and it is determined whether the mold's heating power meets the requirements.

[0093] If the positional deviation of the upper and lower molds during mold closing is greater than the preset first deviation, then the operational stability of the mold is determined to be non-compliant, and the reasons for non-compliance are determined, including:

[0094] The output flow rate of the mold clamping oil pump does not meet the requirements, or the effectiveness of injection molding control does not meet the requirements;

[0095] If the positional deviation of the upper and lower molds during mold closing is greater than the preset first deviation and less than or equal to the preset second deviation, then increase the output flow rate of the mold closing oil pump.

[0096] If the positional deviation of the upper and lower molds during mold closing is greater than the preset second deviation, it is preliminarily determined that the control effectiveness of injection molding does not meet the requirements, and the control effectiveness of injection molding is determined based on the fluctuation range of injection pressure.

[0097] It is understandable that the three intervals divided by the preset first deviation and the preset second deviation correspond to three different scenarios:

[0098] The first interval is when the positional deviation of the upper and lower molds during mold closing is less than or equal to the preset first deviation, which corresponds to the situation where the mold's operational stability meets the requirements.

[0099] The second range is when the positional deviation of the upper and lower molds during mold closing is greater than the preset first deviation and less than or equal to the preset second deviation. The corresponding situation is: due to the aging and deformation of the sealing ring in the mold closing cylinder after long-term use, the leakage inside the cylinder increases, resulting in insufficient mold closing force.

[0100] The third interval is when the positional deviation of the upper and lower molds during mold closing is greater than the preset second deviation. The corresponding situation is that impurities in the hydraulic oil may enter the gap between the valve core and the valve sleeve of the hydraulic valve, hindering the normal movement of the valve core, causing it to jam, resulting in a drop in injection pressure.

[0101] It is understandable that the preset first deviation and preset second deviation can be set according to actual operating conditions. The preset first deviation and preset second deviation are designed to improve the stability and practicality of the circuit breaker housing molding process. Optionally, the preset first deviation and preset second deviation are determined through a limited number of tests by evaluating the molding effect of different positional differences on the circuit breaker housing. The determined preset first deviation and preset second deviation should be detectable without causing excessive interference to the mold closing operation. For example, the preset first deviation is generally selected in the range of [0.09mm, 0.11mm], and the preset second deviation is generally selected in the range of [0.12mm, 0.14mm].

[0102] Preferably, the first deviation is preset to 0.1 mm, and the second deviation is preset to 0.13 mm.

[0103] Specifically, the positional deviation of the upper and lower molds during mold closing is the distance between the left edge of the upper mold and the left edge of the lower mold during mold closing.

[0104] In practice, the method of the present invention determines the operational stability of the mold by setting a preset first deviation amount and a preset second deviation amount, thereby reducing the impact of the decrease in the molding stability of the circuit breaker housing due to the inaccurate determination of the operational stability of the mold, and further improving the molding stability of the circuit breaker housing.

[0105] Specifically, the increase in the output flow rate of the mold closing oil pump is proportional to the difference between the positional deviation of the upper and lower molds during mold closing and the preset first deviation.

[0106] Specifically, when the difference between the positional deviation of the upper and lower molds during mold closing and the preset first deviation is within 0.05mm, the output flow rate of the mold closing oil pump increases to 1.2 times the original value. When the difference between the positional deviation of the upper and lower molds during mold closing and the preset first deviation exceeds 0.05mm, in addition to increasing to 1.2 times the original value, the output flow rate of the mold closing oil pump increases by 0.5L / min for every 0.02mm exceeding the original value. For example, if the difference between the positional deviation of the upper and lower molds during mold closing and the preset first deviation is 0.09mm, and the current output flow rate of the mold closing oil pump is 15L / min, the increased output flow rate of the mold closing oil pump will be 15×1.2+0.5×2=19L / min.

[0107] In practice, the method of the present invention adjusts the output flow rate of the mold closing oil pump by setting a preset first deviation amount and a preset second deviation amount. After long-term use, the sealing ring in the mold closing cylinder ages and deforms, resulting in increased leakage in the cylinder and insufficient mold closing force. By increasing the output flow rate of the mold closing oil pump, the oil replenishment speed can be accelerated, the pressure replenishment time can be shortened, and insufficient mold closing force can be avoided due to pressure recovery lag, thereby maintaining the pressure stability in the cylinder and further improving the molding stability of the circuit breaker housing.

[0108] Specifically, the process of determining whether the control effectiveness of injection molding meets the requirements based on the fluctuation range of the injection pressure includes:

[0109] Compare the fluctuation range of the injection pressure with the preset fluctuation range;

[0110] If the fluctuation range of the injection pressure is less than or equal to the preset fluctuation range, it is determined that the control effectiveness of injection meets the requirements, but the operation stability of the mold does not meet the requirements, and it is determined whether the output flow rate of the mold clamping oil pump meets the requirements.

[0111] If the fluctuation range of the injection pressure is greater than the preset fluctuation range, it is determined that the control effectiveness of the injection molding does not meet the requirements, and the no-load running time of the hydraulic pump in the injection molding machine is increased.

[0112] It is understandable that the two preset fluctuation ranges correspond to two different scenarios:

[0113] The first interval is when the fluctuation range of the injection pressure is less than or equal to the preset fluctuation range, which corresponds to the situation where the control effectiveness of injection molding meets the requirements.

[0114] The second range is when the fluctuation range of the injection pressure is greater than the preset fluctuation range. The corresponding situation is that impurities in the hydraulic oil may enter the gap between the valve core and the valve sleeve of the hydraulic valve, hindering the normal movement of the valve core, causing it to jam, resulting in a drop in injection pressure.

[0115] Understandably, the preset fluctuation range can be set according to actual operating conditions. The preset fluctuation range is designed to ensure the stability and practicality of the circuit breaker housing during molding. Optionally, the preset fluctuation range is determined through a limited number of tests by evaluating the molding effect of different injection pressures on the circuit breaker housing. The determined preset fluctuation range should be detectable without causing excessive interference to the operation of the injection molding machine. For example, the preset fluctuation range is typically selected within the range of [5MPa, 7MPa].

[0116] Preferably, the preset fluctuation range is 6 MPa in the preferred embodiment.

[0117] In practice, the method of the present invention determines the control effectiveness of injection molding by setting a preset fluctuation range, thereby reducing the impact of the decrease in the molding stability of the circuit breaker housing caused by the inaccurate determination of the control effectiveness of injection molding, and further improving the molding stability of the circuit breaker housing.

[0118] Specifically, the fluctuation range of the injection pressure is the difference between the maximum and minimum injection pressure within a single cycle.

[0119] Specifically, the increase in the idle running time of the hydraulic pump in the injection molding machine and the fluctuation range of the injection pressure are proportional to the difference between the preset fluctuation range and the preset fluctuation range.

[0120] Specifically, when the difference between the fluctuation range of the injection pressure and the preset fluctuation range is within 2 MPa, the no-load running time of the hydraulic pump in the injection molding machine increases to 1.2 times the original value. When the difference between the fluctuation range of the injection pressure and the preset fluctuation range exceeds 2 MPa, in addition to increasing to 1.2 times the original value, for every 0.5 MPa exceeding the preset fluctuation range, the no-load running time of the hydraulic pump in the injection molding machine increases by 0.5 seconds. For example, if the difference between the fluctuation range of the injection pressure and the preset fluctuation range is 3 MPa, and the current no-load running time of the hydraulic pump in the injection molding machine is 5 seconds, the increased no-load running time of the hydraulic pump in the injection molding machine will be 5 × 1.2 + 0.5 × 2 = 7 seconds.

[0121] In practice, the method of the present invention adjusts the no-load running time of the hydraulic pump in the injection molding machine by setting a preset fluctuation range. Since impurities in the hydraulic oil may enter the gap between the valve core and the valve sleeve of the hydraulic valve, hindering the normal movement of the valve core and causing it to jam, resulting in a drop in injection pressure, by increasing the no-load running time of the hydraulic pump in the injection molding machine, the flushing effect of the oil flow can be used to carry out the tiny impurities in the gap between the valve core and the valve sleeve, improve the valve core's mobility, alleviate the pressure drop caused by jamming, improve the stability of injection pressure, and further improve the molding stability of the circuit breaker housing.

[0122] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A smart molding method for circuit breaker housings, characterized in that, include: Plastic raw materials are added to the injection molding machine to output molten plastic raw materials, the upper and lower molds are closed to form a mold, and the molten plastic raw materials are injected into the mold. After performing pressure holding and cooling operations on the mold in sequence, the mold is opened to output a semi-finished housing, and the surface of the semi-finished housing is trimmed to output a circuit breaker housing. Obtain the temperature at different locations during mold closing and calculate the maximum temperature difference during mold closing; The molding stability of the circuit breaker housing is determined based on the maximum temperature difference between the molds. If the molding stability does not meet the requirements, determine whether to increase the heating power of the mold; If it is not necessary to increase the heating power of the mold, the operational stability of the mold is determined based on the positional deviation of the upper and lower molds during mold closing. If the operational stability does not meet the requirements, determine whether to increase the output flow rate of the mold clamping oil pump; If it is not necessary to increase the output flow rate of the clamping oil pump, then determine whether to increase the no-load running time of the hydraulic pump in the injection molding machine based on the fluctuation range of the injection pressure. Determining the molding stability of the circuit breaker housing includes: Compare the maximum temperature difference during mold closing with the preset first difference amount; If the maximum temperature difference of the mold is less than or equal to the preset first difference, then the molding stability of the circuit breaker housing is determined to meet the requirements. If the maximum temperature difference during mold closing exceeds the preset first difference, then the molding stability of the circuit breaker housing is determined to be non-compliant, and the reasons for non-compliance are determined, including: The mold's operational stability does not meet requirements, or the mold's heating power does not meet requirements; The process of determining whether the cause is due to the mold's operational stability not meeting requirements includes: The maximum temperature difference in the mold closing process is compared with a preset second difference. If the maximum temperature difference during mold closing is greater than the preset first difference and less than or equal to the preset second difference, it is preliminarily determined that the mold's operational stability does not meet the requirements, and the operational stability of the mold is determined based on the positional deviation of the upper and lower molds during mold closing. The process of determining whether the cause is that the heating power of the mold does not meet the requirements includes: Compare the maximum temperature difference of the mold closing with the preset second difference amount; If the maximum temperature difference of the mold closing is greater than the preset second difference, then the heating power of the mold is increased; The increase in the heating power of the mold and the maximum temperature difference when the mold is closed are proportional to the difference between the preset second difference.

2. The intelligent molding method for circuit breaker housings according to claim 1, characterized in that, The stability of the mold's operation is determined based on the positional deviation between the upper and lower molds during mold closing, including: The positional deviations of the upper and lower molds during mold closing are compared with the preset first deviation and the preset second deviation, respectively. If the positional deviation of the upper and lower molds in the mold closing process is less than or equal to the preset first deviation, then it is determined that the mold's operational stability meets the requirements, while the molding stability of the circuit breaker housing does not meet the requirements, and it is determined whether the mold's heating power meets the requirements. If the positional deviation of the upper and lower molds during mold closing is greater than the preset first deviation, then the operational stability of the mold is determined to be non-compliant, and the reasons for non-compliance are determined, including: The output flow rate of the mold clamping oil pump does not meet the requirements, or the effectiveness of injection molding control does not meet the requirements; If the positional deviation of the upper and lower molds during mold closing is greater than the preset first deviation and less than or equal to the preset second deviation, then increase the output flow rate of the mold closing oil pump. If the positional deviation of the upper and lower molds during mold closing is greater than the preset second deviation, it is preliminarily determined that the control effectiveness of injection molding does not meet the requirements, and the control effectiveness of injection molding is determined based on the fluctuation range of injection pressure.

3. The intelligent molding method for circuit breaker housings according to claim 2, characterized in that, The increase in the output flow rate of the mold closing oil pump is proportional to the difference between the positional deviation of the upper and lower molds during mold closing and the preset first deviation.

4. The intelligent molding method for circuit breaker housings according to claim 3, characterized in that, The process of determining whether the control effectiveness of injection molding meets the requirements based on the fluctuation range of the injection pressure includes: Compare the fluctuation range of the injection pressure with the preset fluctuation range; If the fluctuation range of the injection pressure is less than or equal to the preset fluctuation range, it is determined that the control effectiveness of injection meets the requirements, but the operation stability of the mold does not meet the requirements, and it is determined whether the output flow rate of the mold clamping oil pump meets the requirements. If the fluctuation range of the injection pressure is greater than the preset fluctuation range, it is determined that the control effectiveness of the injection molding does not meet the requirements, and the no-load running time of the hydraulic pump in the injection molding machine is increased.

5. The intelligent molding method for circuit breaker housings according to claim 4, characterized in that, The fluctuation range of the injection pressure is the difference between the maximum and minimum injection pressure within a single cycle.

6. The intelligent molding method for circuit breaker housings according to claim 5, characterized in that, The increase in the idle running time of the hydraulic pump in the injection molding machine and the fluctuation range of the injection pressure are proportional to the difference between the preset fluctuation range and the preset fluctuation range.

Images