Evaporator red copper pipe bending processing technology based on automatic adjustment

Abstract

The present application relates to the technical field of red copper pipe bending, and particularly relates to an evaporator red copper pipe bending processing technology based on automatic adjustment, which comprises the following steps: obtaining the actual surface temperature value of the red copper pipe after preheating ends, so as to determine the actual temperature difference value and determine the heating qualification; in response to the determination that the heating is unqualified, the bending angle in the bending processing process is adjusted according to the temperature difference deviation value, and the bending frequency is checked based on the determined bending angle; after the surface temperature of the red copper pipe decreases to the bending temperature, the axial pressure determined according to the bending angle is used to install the supporting material in the pipe, the supporting out-of-control property is determined based on the radial pressure value, so as to determine the axial pressure adjustment state; the present application can comprehensively evaluate the performance of the red copper pipe in the bending processing process from a single direction and multiple dimensions, automatically adjust the parameters of the bending processing, optimize the bending quality and the bending efficiency, and improve the yield of the red copper pipe bending.

Description

Technical Field

[0001] This invention relates to the field of copper tube bending technology, and in particular to a copper tube bending process for evaporators based on automated adjustment. Background Technology

[0002] Existing technologies for bending copper tubes can perform basic bending operations, complete the bending and forming of copper tubes for evaporators, and allow manual setting of basic parameters such as bending radius and bending angle. Simple internal support structures can also be used to reduce bending wrinkles. At the same time, conventional heating methods can be used to enhance the plasticity of copper tubes to assist bending. However, multiple parameters cannot be linked together; copper tube bending can only be performed by setting fixed parameters.

[0003] Chinese Patent Publication No. CN119794147A discloses a multi-dimensional spatial bending copper tube forming robot system, including a horizontal guide rail (a) and a vertical rotating shaft. A driving device can drive the rotating shaft to rotate. One end of the guide rail (a) is fixed on the rotating shaft and rotates synchronously with the rotating shaft. A horizontal copper tube bending constraint block is fixed to the upper end of the rotating shaft. A slider (a) is provided on the guide rail (a), and a driving structure can drive the slider (a) to move along the length direction of the guide rail (a). A clamping block with the same height as the copper tube bending constraint block is fixed to the upper end of the slider (a). Therefore, the multi-dimensional spatial bending copper tube forming robot system has the following problems:

[0004] It is not possible to comprehensively evaluate the performance of copper tubes during the bending process from a single direction and multiple dimensions, to automatically adjust the bending parameters, optimize bending quality and efficiency, and improve the yield of bent copper tubes. Summary of the Invention

[0005] Therefore, this invention provides an automated adjustment-based bending process for evaporator copper tubes to overcome the problem that existing technologies cannot comprehensively evaluate the performance of copper tubes during the bending process from a single direction and multiple dimensions, automatically adjust bending parameters, optimize bending quality and efficiency, and improve the yield rate of bent copper tubes.

[0006] To achieve the above objectives, this invention provides a bending process for evaporator copper tubes based on automated adjustment, comprising:

[0007] The actual surface temperature of the preheated copper tube at the end of heating is obtained to determine the actual temperature difference and the heating qualification. In response to the determination of heating failure, the bending angle during the bending process is adjusted according to the temperature difference deviation value, and the number of bending times is verified based on the determined bending angle.

[0008] In response to the determination that the heating is unqualified, the preheating temperature of the copper tube in the subsequent bending process is adjusted;

[0009] After the surface temperature of the copper tube drops to the bending temperature, the internal support material is installed with axial pressure determined according to the bending angle. The radial pressure value of the internal support material with radial deformation on the inner wall of the copper tube is obtained. The support failure is determined based on the radial pressure value to determine the axial pressure regulation state.

[0010] During the bending process, the bending temperature value determined based on the surface temperature of the copper tube is used to determine the runaway of bending conditions in order to determine the bending process status.

[0011] Based on the situation where the actual temperature difference is greater than the preset temperature difference, or the radial pressure value does not belong to the preset pressure range, or the bending temperature value is less than the bending standard temperature value, bending evaluation parameters are constructed according to the first deviation rate, the second deviation rate, and the third deviation rate determined by the actual temperature difference exceeding the preset temperature difference to determine the qualification of bending quality. In response to the determination that the bending quality is unqualified, the subsequent bending speed is adjusted according to the excess value.

[0012] The actual temperature difference value is determined based on the actual temperature value and the target temperature value, and the excess value is determined based on the bending evaluation parameters and the preset evaluation parameters.

[0013] Furthermore, the process of controlling the bending angle during the bending process includes,

[0014] Comparing the actual temperature difference with the preset temperature difference, if the actual temperature difference is greater than the preset temperature difference, the heating is deemed unqualified. The bending angle during the bending process is adjusted to decrease based on the temperature difference deviation. The temperature difference deviation is determined based on the difference between the actual temperature difference and the preset temperature difference. The actual temperature difference is determined based on the highest actual temperature value of the copper tube surface and the target temperature value.

[0015] Furthermore, the process of verifying the number of bends based on the determined bending angle includes,

[0016] Compare the bending angle with the preset bending angle range. If the bending angle is not within the preset bending angle range, determine that the number of bending times increases.

[0017] Furthermore, the process of determining the axial pressure control state includes,

[0018] By comparing the radial pressure value with the risk pressure range, if the radial pressure value does not fall within the risk pressure range, it is determined that the support is out of control. The direction of axial pressure adjustment is determined based on the deviation of the radial pressure value from the risk pressure range.

[0019] Furthermore, in response to the determination that the support is not out of control, the radial pressure value is compared with the preset pressure range. Based on the fact that the radial pressure value does not belong to the preset pressure range, the support is determined to be unqualified. The bending quality is determined by constructing a second deviation rate determined by the median value of the radial pressure value deviating from the preset pressure range.

[0020] Furthermore, the process of determining the bending processing state includes,

[0021] By comparing the bending temperature value with the bending standard temperature value, if the bending temperature value is less than the bending standard temperature value, the bending condition is deemed unqualified. Based on the relationship that the bending temperature value is less than the bending evaluation temperature value, the bending process is stopped and preheating is performed again.

[0022] Furthermore, in response to the determination that the bending conditions are unqualified, the bending temperature value is compared with the bending evaluation temperature value. Based on the bending temperature value being greater than or equal to the bending evaluation temperature value, it is determined that the bending conditions are not out of control. The bending quality is judged by constructing the bending evaluation parameters based on the third deviation rate determined by the bending temperature value being lower than the bending standard temperature value.

[0023] Furthermore, the process of adjusting the subsequent bending speed based on the exceeded value includes,

[0024] By comparing the bending evaluation parameters with the preset evaluation parameters, if the bending evaluation parameters are greater than the preset evaluation parameters, the bending quality is determined to be unqualified. Based on the excess value and the current bending speed, the subsequent bending speed is adjusted to reduce the bending speed.

[0025] Furthermore, based on the condition that the actual temperature difference is less than or equal to the preset temperature difference, the radial pressure value belongs to the preset pressure range, and the bending temperature value is greater than or equal to the bending standard temperature value, the runaway evaluation parameters are adjusted according to the preset adjustment amount. The runaway evaluation parameters include the risk temperature difference, the risk pressure range, and the bending evaluation temperature value.

[0026] Furthermore, in response to adjusting the runaway evaluation parameters according to the preset adjustment amount, the control risk temperature difference value decreases, the control risk pressure range shrinks from both ends to the middle value, and the control bending evaluation temperature value increases.

[0027] Compared with the prior art, the beneficial effect of the evaporator copper tube bending process based on automatic adjustment of the present invention is that it can comprehensively evaluate the performance of the copper tube in the bending process from a single direction and multiple dimensions, automatically adjust the bending parameters, optimize the bending quality and bending efficiency, and improve the yield of copper tube bending.

[0028] Furthermore, by detecting the highest temperature at which the copper tube recovers its plasticity through heating, the plasticity of the copper tube is evaluated. The pass rate of plasticity recovery is determined based on the actual temperature difference. This allows for the determination of the single-bending angle during the bending process based on the copper tube's plasticity, ensuring the quality of bending in multiple bending operations. This avoids quality problems such as cracking caused by excessive bending angles during a single bending operation due to insufficient plasticity. In cases where insufficient actual temperature leads to insufficient plasticity or excessively high actual temperature results in grain coarsening and increased deformation resistance, the bending angle is redefined to ensure the production of qualified products. Fixed bending angle settings prevent abnormalities caused by excessively high or low actual temperatures. This intelligent and automated matching of bending angles to the actual temperature of the copper tube improves the yield rate of the bent copper tube.

[0029] Furthermore, the plasticity of the copper tube during bending is evaluated by detecting the highest temperature at which it is heated to restore its plasticity. The absolute value of the difference between the actual and target temperatures (i.e., the actual temperature difference) is compared with the preset temperature difference to determine whether the current heating process for restoring plasticity is satisfactory. If satisfactory, bending is performed at the preset bending angle. If unsatisfactory, the bending angle is reduced to avoid large-angle bending due to insufficient plasticity, which could cause cracking during bending. Therefore, the actual temperature at which the copper tube is heated to restore its plasticity is assessed. The absolute value of the difference between the temperature value and the target temperature value, i.e., the actual temperature difference value, is used to adjust the angle during bending to ensure that the copper tube can be bent reasonably under the current plasticity recovery condition. This ensures that the copper tube will not crack or have other defects after bending, thereby improving the yield rate. The plasticity of the copper tube is increased by adjusting the heating temperature in the subsequent process, which in turn makes up for the insufficiency of the previous bending angle in the subsequent bending process. If the insufficiency of the previous bending angle cannot be made up, that is, if the current bending angle and the number of bending times are insufficient to meet the bending requirements, the number of bending times is increased to fully ensure the quality of the bending process.

[0030] Furthermore, if the current heating is deemed unqualified, a more in-depth assessment is conducted. The heating temperature required to restore the plasticity of the copper tube is further determined, and it is determined whether the current heating exceeds the controllable boundary. If it does not exceed the controllable boundary, the insufficient bending angle in the initial bending process can be compensated for through subsequent bending processes. If it exceeds the controllable boundary, it indicates that the plasticity of the copper tube has been severely deteriorated. In this case, the bending process can only be completed by increasing the number of bending cycles and simultaneously adjusting the bending angle distribution for each cycle, and re-bending the tube according to the bending target. This ensures that the bending efficiency and bending quality are balanced automatically, and that the bending speed is maintained while ensuring that no performance defects occur during the bending process of the copper tube, thus completing the bending process according to the bending target.

[0031] Furthermore, by detecting the radial pressure value of the internal support material on the copper tube, the system can control whether wrinkles or collapses occur during the bending of the copper tube. This allows for the determination of support quality and support control failure, and targeted adjustments are made based on the corresponding results. If the support is determined to be out of control, the support force of the internal support material on the copper tube is adjusted to ensure that the copper tube will not wrinkle, collapse, or become flattened due to insufficient support force in one dimension during the bending process, thus affecting the internal fluid flow when the product is used in the evaporator. The radial pressure value is used to judge the support effect of the internal support material on the current copper tube bending process, ensuring timely automated feedback and dynamic adjustment of the radial pressure value. This ensures that structural defects caused by insufficient support force do not occur during the bending process, ultimately achieving the high-precision roundness and flow channel consistency required for the copper tube in the application of key components of the evaporator.

[0032] Furthermore, the effectiveness of the nylon rod's internal support for the copper tube is determined by detecting the radial pressure value. When the radial pressure value is too small or too large, or when all qualification criteria are unqualified, a bending evaluation parameter is constructed using a second deviation rate. This bending evaluation parameter comprehensively evaluates the bending quality of the copper tube during bending from multiple dimensions and allows for corresponding adjustments. This avoids the impact of single-direction adjustments on bending speed due to unqualified support. When unqualified support is determined, the degree of unqualified support is further analyzed to avoid overlooking abnormal situations in a single dimension, such as when the radial pressure value is much lower than the lower limit of the preset pressure range or much higher than the upper limit, leading to performance damage or product scrapping. Therefore, by comprehensively judging the bending quality from multiple dimensions and further analyzing the effectiveness of the nylon rod's internal support for the copper tube from a single dimension, the bias caused by a single judgment is avoided, thus ensuring the performance stability of the copper tube during bending.

[0033] Furthermore, by constructing bending evaluation parameters through a second deviation rate when the support is deemed unqualified, the bending quality of the copper tube during bending is comprehensively evaluated from multiple dimensions and corresponding adjustments are made. At the same time, the support of the nylon rod on the inner wall of the copper tube is further evaluated from a single dimension. This avoids situations where the nylon rod's support for the inner wall of the copper tube is out of control, i.e., the radial pressure value is too high or too low, which cannot effectively support the copper tube during the bending process, or even cause reverse damage to the copper tube. For example, excessive radial pressure can lead to increased friction, causing scratches or even micro-cracks on the inner wall of the copper tube during bending, resulting in performance defects and making the copper tube unusable in the evaporator. Conversely, insufficient radial pressure can fail to provide effective support to the inside of the copper tube, leading to wrinkles, collapses, or cross-sectional distortions during bending, which in turn affects the uniformity of refrigerant flow and heat exchange efficiency inside the evaporator. If the support is determined to be out of control, the axial pressure is adjusted to ensure the support is qualified. Then, by sacrificing some bending efficiency, the bending quality is ensured, avoiding the increase in the defect rate of copper tube bending due to excessive pursuit of bending efficiency. In this way, the bending process of copper tube is automatically controlled to optimize the quality and efficiency of copper tube bending.

[0034] Furthermore, by monitoring the bending temperature during the bending process, the current bending conditions are assessed for compliance. The bending temperature affects the bending quality of the copper tube under the current bending process. Therefore, if all compliance assessments are unsatisfactory and the current bending process poses a risk, a bending evaluation parameter is constructed using a third deviation rate. This parameter comprehensively evaluates the bending quality of the copper tube from multiple dimensions and allows for corresponding adjustments. Simultaneously, a deeper assessment is made regarding the bending temperature to determine if the current temperature is out of control and no longer meets the bending requirements. This allows for a comprehensive assessment of the bending quality compliance while simultaneously identifying the risk of continuing bending processes from a single perspective. This ensures that while comprehensively assessing the bending quality, it also prevents a single-dimensional breach of bending requirements from going unnoticed, leading to a loss of quality control, reduced bending efficiency, and lower yield.

[0035] Furthermore, if the bending conditions are deemed unqualified, the degree of control over the bending conditions is further determined. If the bending conditions are not out of control, the bending quality of the copper tube during the bending process is comprehensively evaluated from multiple dimensions using bending evaluation parameters, and corresponding adjustments are made to automatically balance the bending quality and bending efficiency. When the bending conditions are determined to be out of control, it indicates that the current bending conditions do not meet the requirements of the bending process, and the current bending process needs to be stopped, the copper tube reheated, and the bending process restarted after the plastic properties are restored. This ensures the bending quality of the copper tube and improves the yield rate of the copper tube.

[0036] Furthermore, by constructing bending evaluation parameters when all conformity assessments fail, and deepening the assessment in a single direction, the bending quality of the copper tube is comprehensively judged using multi-dimensional bending evaluation parameters. This allows for targeted adjustment of the bending speed when the bending quality is deemed unqualified. This prevents the bending process from becoming uncontrollable in multiple directions when conformity assessments fail, without adjustment, which could lead to a decline in bending quality and cause cracking or wrinkling during copper tube bending. Therefore, even when the process is not deemed uncontrollable, reducing the bending speed to compensate for insufficient bending quality ensures that the copper tube will not crack, wrinkle, or collapse during bending, thereby improving the yield rate of bent copper tubes.

[0037] Furthermore, when all conformity assessments are satisfactory, the runaway assessment parameters are adjusted according to preset adjustment amounts. In the event of a single conformity assessment failure, the system responds in advance to the single runaway assessment, thereby improving the accuracy of copper tube bending, ensuring automated adjustment of parameters during the bending process, and further guaranteeing the quality and efficiency of copper tube bending. Attached Figure Description

[0038] Figure 1 This is a flowchart of the evaporator copper tube bending process based on automated adjustment according to the present invention.

[0039] Figure 2 This is a flowchart for determining the heating qualification of the present invention;

[0040] Figure 3 This is a flowchart illustrating the process of determining heating runaway in this invention;

[0041] Figure 4 This is a flowchart for determining the passability and uncontrollability of the support according to the present invention. Detailed Implementation

[0042] 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.

[0043] 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.

[0044] Please see Figure 1 The following is a detailed description of an embodiment of an evaporator copper tube bending process based on automated adjustment;

[0045] This invention relates to an automated adjustment process for bending evaporator copper tubes, comprising:

[0046] Step S1: Obtain the actual surface temperature of the preheated copper tube at the end of heating to determine the actual temperature difference value and determine the heating qualification. In response to the determination of heating failure, adjust the bending angle during the bending process according to the temperature difference deviation value, and verify the number of bending times based on the determined bending angle.

[0047] The short-wave infrared thermal imager acquires the color of the copper tube at the bending position and outputs the actual temperature value of the copper tube surface after heating. The actual temperature difference is determined by comparing the actual temperature value with the target temperature value. The target temperature value is the expected temperature at which the copper tube is heated to restore its plasticity. For the copper tube with a diameter of 12mm, a wall thickness of 1.2mm, and a bending radius of 12mm that is being bent in this embodiment, the target temperature is 550℃.

[0048] The heating module preferably uses a medium-frequency induction heating machine to heat the bending area. The heating width is greater than the required bending width, ensuring that deformation during processing does not occur only at the bending point. Uniform heating of the area near the bending point increases the stability of the copper tube bending process by ensuring simultaneous stress in this region. This prevents uneven stress on the heated and unheated areas during bending, which could lead to cracks in the copper tube. Alternatively, the heating width can be just sufficient for the bending process. The width is important, but because the critical position is not heated, the stress release at the bending position is uneven, which affects the effect of the next bending process. The heating temperature affects the plasticity and deformation uniformity of the copper tube during bending. When the heating temperature is too low, the yield strength of the copper tube is too high and the plasticity is insufficient. During the bending process, the copper tube is too hard and brittle. If a large-angle bending process is carried out at this time, the outer wall of the copper tube will be too thin or even crack. If the heating temperature is too high, the grains of the copper tube will grow excessively and coarse grains will appear. The surface of the copper tube is prone to orange peel and roughness, the strength will decrease, and the tube wall will be too thin.

[0049] The preheating temperature typically ranges from 500 to 600°C. In this embodiment, 550°C is used to facilitate temperature adjustment during subsequent bending processes, preventing significant deviations from the target processing effect during the initial bending. The bending temperature is determined based on the inner support material, preferably nylon rods. Nylon rods begin to soften noticeably above 100°C. To ensure good support of the nylon rods for the inner wall of the copper tube, the bending temperature range is typically 50-80°C. Setting the bending temperature to 78°C balances cooling efficiency and material plasticity retention, ensuring the bending effect and preventing the inner support material from losing its support performance due to high bending temperatures. The preheating time is typically determined based on the parameters of the copper tube. In this embodiment, taking a diameter of 12mm, a wall thickness of 1.2mm, and a bending radius of 12mm as an example, the preheating time ranges from 3 to 8 seconds, preferably 6 seconds, to ensure sufficient recovery of the copper tube's plasticity and prevent coarse grains from forming due to excessive heating time.

[0050] This invention evaluates the plasticity of copper tubes by detecting the temperature at which they recover their plasticity through heating. The success of this process is determined based on the actual temperature difference, allowing for the determination of the single-bending angle during bending. This ensures consistent bending quality even in multi-stage bending processes, preventing issues like cracking caused by excessive bending angles due to insufficient plasticity. Furthermore, the invention re-determines the bending angle to ensure quality products are produced even at low or high temperatures, preventing abnormalities caused by fixed bending angles. This intelligent and automated matching of bending angles to the actual temperature of the copper tube improves the yield rate of bent copper tubes.

[0051] Please see Figure 2 The process for determining the success of heating is shown in detail below.

[0052] Specifically, the process of adjusting the bending angle during the bending process includes,

[0053] By comparing the actual temperature difference with the preset temperature difference, if the actual temperature difference is greater than the preset temperature difference, the heating is deemed unqualified. The bending angle during the bending process is reduced according to the temperature difference deviation. The temperature difference deviation is determined based on the difference between the actual temperature difference and the preset temperature difference. The actual temperature difference is determined based on the actual surface temperature of the copper tube and the target temperature.

[0054] Compare the actual temperature difference with the preset temperature difference to determine the heating qualification and determine the subsequent bending angle; if the actual temperature difference is less than or equal to the preset temperature difference, the heating is deemed qualified; if the actual temperature difference is greater than the preset temperature difference, the heating is deemed unqualified.

[0055] The preset temperature difference value is determined based on experience regarding the bending effect of the copper tube during bending processing. Since the short-wave infrared thermal imager acquires the color at the bending location of the copper tube, the output temperature value itself has a certain error, typically less than ±5℃. Therefore, the preset temperature difference value is set to 10℃ to avoid the error of the preset temperature difference being too small, which would render the temperature detection ineffective. When the actual temperature difference value is ≤ the preset temperature difference value, indicating that heating is qualified, bending is performed according to the preset bending angle. Different bending angles are set for copper tubes of different diameters, wall thicknesses, and bending radii. In this embodiment, a copper tube with a diameter of 12mm, a wall thickness of 1.2mm, and a bending radius of 12mm is used, and the total bending angle for a single bending process is... Taking a 180° serpentine bend with a bending radius equal to one diameter as an example, the bending process is improved by increasing the number of bends to reduce the bending angle per bend. This prevents the outer wall from becoming too thin or even cracking due to large deformation during a single bend, which would affect the quality of the copper tube bending process. The total bending angle at a single point is divided into at least three bends. When divided into three bends, the preset bending angle is set to 61°. After each bend, the copper tube will exhibit a certain degree of springback. A preset springback angle ensures that the final bent copper tube achieves the target bending effect. When the actual temperature difference exceeds the preset temperature difference, the heating is deemed unqualified. The actual temperature value is then compared with the target temperature value. If the actual temperature value is less than the target temperature value, the adjustment is determined to be insufficient. The bending angle is then reduced. At this point, heating is inadequate, and the heating temperature does not reach the target temperature. If the preset bending angle is maintained, the outer wall of the copper tube may become too thin or even crack. Therefore, the preset bending angle is reduced. The adjustment amount of the preset bending angle is positively correlated with the temperature difference deviation between the actual and preset temperature differences. The temperature difference deviation is the difference between the actual and preset temperature differences. For every 1°C increase in the temperature difference deviation, the bending angle decreases by 1°. If the actual temperature is greater than the target temperature, it indicates that the current heating effect of the copper tube is good, and bending can be performed according to the preset bending angle. If the previous bending process resulted in a bending angle smaller than the preset bending angle, a certain degree of bending can be performed in this bending process. The bending angle is compensated by increasing the current bending angle to make up for the insufficient bending angle in the previous bending. When adjusting the current bending angle, the angle adjustment amount of the preset bending angle is positively correlated with the temperature difference deviation of the actual temperature value relative to the preset temperature difference value. Whenever the temperature difference deviation increases by 1°, the bending angle increases by 1°. If the heating is deemed unqualified, the preheating temperature needs to be re-determined to ensure the qualified heating of the copper tube by the subsequent heating module. If the current actual temperature difference value is greater than the preset temperature difference value, the preheating temperature is adjusted according to the temperature deviation rate of the actual temperature difference value relative to the target temperature value. If the current actual temperature difference value is 15°, and the current actual temperature value is 535°, then the adjusted preheating temperature for subsequent bending processing is 565°.

[0056] Step S2: In response to the determination that the heating is unqualified, the preheating temperature of the copper tube in the subsequent bending process is adjusted.

[0057] Specifically, the process of verifying the number of bends based on a determined bending angle includes,

[0058] Compare the actual bending angle with the preset bending angle range. If the bending angle is not within the preset bending angle range, determine that the number of bending times increases.

[0059] If the actual bending angle is within the preset bending angle range, the bending process is performed according to the current number of bending cycles; if the actual bending angle is not within the preset bending angle range, the number of bending cycles is increased by one, and the corresponding bending angle is adjusted. The preset bending angle range is [51°, 71°]. This range avoids both excessively small bending angles requiring multiple preheating cycles, which would slow down the bending process, and the risk of performance defects in the copper tube due to repeated preheating. It also avoids excessively large bending angles that could lead to thin outer tube walls or cracking. If the actual temperature difference is 15°C and the current actual temperature is 535°C, and this is the first bending operation, the preheating temperatures for the subsequent two bending operations will be adjusted to 565°C and 580°C. The second bending operation ensures the bending progress while the third bending operation compensates for the insufficient bending angle in the first operation. If the current bending operation is the second bending operation, the adjusted preheating temperature is 580°C, and the third bending operation compensates for the insufficient bending angle in the second operation. If the current bending operation is the third bending operation, a compensatory bending operation is performed, adding an extra bending operation to compensate for the insufficient bending angle.

[0060] This invention evaluates the plasticity of a copper tube during bending by detecting the highest temperature at which it is heated to restore its plasticity. The absolute value of the difference between the actual and target temperatures (the actual temperature difference) is compared with a preset temperature difference to determine whether the current heating process for restoring plasticity is satisfactory. If satisfactory, bending is performed at a preset bending angle. If unsatisfactory, the bending angle is reduced to avoid large-angle bending due to insufficient plasticity, which could cause cracking during bending. Therefore, the method is based on the actual temperature at which the copper tube is heated to restore its plasticity. The absolute value of the difference between the temperature value and the target temperature value, i.e., the actual temperature difference value, is used to adjust the angle during bending to ensure that the copper tube can be bent reasonably under the current plasticity recovery condition. This ensures that the copper tube will not crack or have other defects after bending, thereby improving the yield rate. The plasticity of the copper tube is increased by adjusting the heating temperature in the subsequent process, which can make up for the insufficiency of the previous bending angle in the subsequent bending process. If the insufficiency of the previous bending angle cannot be made up, that is, if the current bending angle and the number of bending times are insufficient to meet the bending requirements, the number of bending times is increased to fully ensure the quality of the bending process.

[0061] Please see Figure 3 As shown, the process for determining heating runaway is explained in detail;

[0062] The process for determining the runaway heating includes comparing the actual temperature difference with the risk temperature difference to determine the runaway heating; in response to the determination that the heating has runaway, determining that the number of bends has increased and re-determining the bend angle.

[0063] In response to the determination that heating is unqualified, the actual temperature difference value is compared with the risk temperature difference value to determine the degree of heating failure; if the actual temperature difference value is less than the risk temperature difference value, the heating is determined not to be out of control; if the actual temperature difference value is greater than or equal to the risk temperature difference value, the heating is determined to be out of control.

[0064] The risk temperature difference value is determined based on the experience of the bending effect of the copper tube during bending processing and the adjustment amount of the bending angle. In this example, the risk temperature difference value is 20°C, which meets the requirement that the lower limit of the bending angle of a single bending is 51° and the upper limit is 71°. The total bending angle of the three bending processes is controlled at 180° to avoid insufficient bending angle caused by the accumulation of subsequent bending angles due to a small bending angle in a single bending process, or excessive compensation of the bending angle in a single bending process, which may cause the outer wall of the copper tube to be too thin or cracked.

[0065] When the actual temperature difference is less than the risk temperature difference, it is determined that the heating is not out of control. This indicates that although the current heating is unqualified, it is still within the controllable range and can be compensated for by subsequent bending processing.

[0066] When the actual temperature difference is greater than or equal to the risk temperature difference, indicating that heating is out of control, the number of bends should be immediately recalculated. For example, if the current actual temperature difference is 30°C and the current actual temperature is 520°C, the bending angle should be adjusted from 61° to 41° according to the strategy of adjusting the bending angle when heating is deemed unqualified. This exceeds the lower limit of the preset bending angle range. Since the bending angle cannot be compensated for in subsequent bending processes through conventional compensation, the number of bends should be recalculated. By increasing the number of bends and adjusting the corresponding bending angle, the overall angle accuracy of the bending process and the quality of the pipe forming should be ensured.

[0067] In cases where the current heating is deemed unqualified, this invention conducts a further assessment, specifically determining the heating temperature required to restore the plasticity of the copper tube. It then determines whether the current heating exceeds a controllable boundary. If it does not, subsequent bending processes can compensate for insufficient bending angles. If it exceeds the controllable boundary, it indicates that the plasticity of the copper tube has severely deteriorated. In this case, the bending process must be re-executed by increasing the number of bends and simultaneously adjusting the bending angle distribution, ensuring an automated balance between bending efficiency and quality. This guarantees the bending speed while preventing performance defects during the copper tube bending process, and completes the bending process according to the bending target.

[0068] Step S3: Install the pipe support material with the axial pressure determined according to the bending angle, obtain the radial pressure value of the pipe support material with radial deformation on the inner wall of the copper pipe to determine the support failure, so as to determine the axial pressure control state; the pipe support material is preferably a nylon rod.

[0069] The radial pressure value of the support material inside the tube is obtained by a pressure sensor. A tube with the same diameter as the copper tube is set at the end of the copper tube. A pressure sensor is installed on the tube. The radial diameter of the nylon rod is changed by applying axial pressure to the nylon rod, thereby adjusting the radial support force of the nylon rod, i.e., the radial pressure value.

[0070] This invention controls whether wrinkles and collapses occur during the bending of a copper tube by detecting the radial pressure value of the internal support material. It determines the support's suitability and whether it is out of control, and makes targeted adjustments based on the results. If the support is deemed out of control, the invention adjusts the support force of the internal support material to ensure that the copper tube does not wrinkle, collapse, or become flattened due to insufficient support in a single dimension during bending, thus preventing the fluid flow within the evaporator. The radial pressure value is used to judge the support effect of the internal support material during the bending process, ensuring timely automated feedback and dynamic adjustment of the radial pressure value. This prevents structural defects caused by insufficient support during bending, ultimately achieving the high-precision roundness and flow channel consistency required for the copper tube in key evaporator components.

[0071] Please see Figure 4 The process for determining the suitability and uncontrollability of a support is detailed in the diagram.

[0072] The process of determining the passability of the support includes comparing the radial pressure value with a preset pressure range to determine the passability of the support; if the radial pressure value falls within the preset pressure range, the support is deemed passable; if the radial pressure value does not fall within the preset pressure range, the support is deemed failable.

[0073] Specifically, in response to the determination that the support is not out of control, the radial pressure value is compared with the preset pressure range. If the radial pressure value does not belong to the preset pressure range, the support is determined to be unqualified. The bending quality is determined by constructing a second deviation rate determined by the median value of the radial pressure value deviating from the preset pressure range.

[0074] The preset pressure range is determined based on the bending angle of the copper tube and the performance of the nylon rod. It is established through laboratory experiments using data on the parameters of the copper tube, nylon rod, bending angle, bending speed, and the bending effect of the copper tube. The copper tube parameters include outer diameter, wall thickness, and bending radius. The nylon rod parameters include the nylon rod diameter. For example, in this embodiment, the copper tube diameter is 12mm, the wall thickness is 1.2mm, the bending radius is 12mm, the nylon rod diameter is 11.8mm, the bending angle is 61°, and the bending speed is 6° / s. This allows for bending without cracking, wrinkling on the inner side, or flattening. Therefore, the measured pressure range is 2.8-3.8kN. Based on experience, the preset pressure range is set to 3.1-3.5kN. If the current bending angle is 70° and the bending speed is 10° / s, the measured pressure range is 3.2-4.4kN. Based on experience, the preset pressure range is set to 3.6-4.0kN.

[0075] When the radial pressure value is within the preset pressure range and the support is deemed qualified, it indicates that the radial support of the nylon rod on the copper tube is stable and the copper tube has not experienced local instability or plastic collapse during bending. Therefore, it is not necessary to adjust the axial pressure of the nylon rod. At this time, the nylon rod's support on the inner wall of the copper tube is effective and can suppress wrinkles and collapse of the inner wall.

[0076] When the radial pressure value is not within the preset pressure range, it is determined that the support is unqualified. This indicates that the radial support force of the current nylon rod on the copper tube does not reach the target state, and there is a situation where the axial pressure of the nylon rod is insufficient or excessive. At this time, it is necessary to further determine whether the radial support force of the nylon rod is out of control.

[0077] This invention determines the effectiveness of the nylon rod's internal support for the copper tube by detecting the radial pressure value. When the radial pressure value is too small or too large, or when all qualification criteria are unqualified, a bending evaluation parameter is constructed using a second deviation rate. This parameter comprehensively evaluates the bending quality of the copper tube during bending from multiple dimensions and allows for corresponding adjustments. This avoids the impact of single-direction adjustments on bending speed due to unqualified support. When unqualified support is determined, the degree of unqualified support is further analyzed to prevent overlooking abnormal situations in a single dimension, such as performance damage or product scrap caused by radial pressure values ​​far below the lower limit or far above the upper limit of a preset pressure range. Therefore, by comprehensively judging bending quality from multiple dimensions and further analyzing the effectiveness of the nylon rod's internal support from a single dimension, the invention avoids the bias caused by a single judgment, thus ensuring the performance stability of the copper tube during bending.

[0078] Specifically, the process of determining the axial pressure control state includes,

[0079] By comparing the radial pressure value with the risk pressure range, if the radial pressure value does not fall within the risk pressure range, it is determined that the support is out of control. The direction of axial pressure adjustment is determined based on the deviation of the radial pressure value from the risk pressure range.

[0080] Compare the radial pressure value with the risk pressure range to determine the support level's vulnerability; if the radial pressure value falls within the risk pressure range, the support level is considered intact; if the radial pressure value does not fall within the risk pressure range, the support level is considered vulnerable.

[0081] The risk pressure range is determined based on experimental data from the laboratory regarding the parameters of the copper tube, the parameters of the nylon rod, the bending angle, the bending speed, and the bending effect of the copper tube. For example, the risk pressure range is 2.8-3.8 kN.

[0082] When the radial pressure value is within the risk pressure range, it is determined that the support is not out of control. At this time, although the support is deemed unqualified, the supporting force of the nylon rod on the inner wall of the copper tube is still within the controllable range, and the quality of the copper tube bending process can still be guaranteed.

[0083] When the radial pressure value is outside the risk pressure range, indicating that the support is out of control, it means that the current radial support force of the nylon rod on the copper tube is out of control. This could result in insufficient support leading to wrinkles after the copper tube bends, or excessive support causing tearing, increased wear, and high springback force on the inner wall of the copper tube. Therefore, it is necessary to redetermine the axial pressure of the nylon rod. The axial pressure should be adjusted based on the second deviation rate of the radial pressure value relative to the median value of the risk pressure range. For example, if the current radial pressure value is 2.5 kN and the corresponding axial pressure is 0.5 kN, then the current second deviation rate is |2.5 - 3.3| / 3.3 = 24.2%; the axial pressure should then be adjusted to 0.5 kN × (1 + 24.2%) = 0.62 kN. If the current radial pressure value is 4 kN and the corresponding axial pressure is 0.8 kN, then the current second deviation rate is |4 - 3.3| / 3.3 = 21.2%; the axial pressure should then be adjusted to 0.8 kN × (1 - 21.2%) = 0.63 kN.

[0084] This invention, when the support is deemed unqualified, constructs a bending evaluation parameter using a second deviation rate. This parameter comprehensively evaluates the bending quality of the copper tube during bending from multiple dimensions and allows for corresponding adjustments. Simultaneously, it further assesses the support of the nylon rod on the inner wall of the copper tube from a single dimension. This avoids situations where the nylon rod's support for the inner wall of the copper tube is out of control (i.e., the radial pressure value is too high or too low), failing to effectively support the copper tube during bending and potentially causing reverse damage. For example, excessive radial pressure can lead to increased friction, causing scratches or even micro-cracks on the inner wall of the copper tube during bending, resulting in performance defects and rendering the copper tube unusable in the evaporator. Conversely, insufficient radial pressure can fail to provide effective support, leading to wrinkles, collapses, or cross-sectional distortion during bending, thus affecting the uniformity of refrigerant flow and heat exchange efficiency within the evaporator. If the support is determined to be out of control, the axial pressure is adjusted to ensure the support is qualified. Then, by sacrificing some bending efficiency, the bending quality is ensured, avoiding the increase in the defect rate of copper tube bending due to excessive pursuit of bending efficiency. In this way, the bending process of copper tube is automatically controlled to optimize the quality and efficiency of copper tube bending.

[0085] Step S4: During the bending process, the bending temperature value determined based on the surface temperature of the copper tube is used to determine the uncontrollability of the bending conditions in order to determine the bending process status.

[0086] Specifically, the process of determining the bending processing state includes,

[0087] By comparing the bending temperature value with the bending standard temperature value, if the bending temperature value is less than the bending standard temperature value, the bending condition is deemed unqualified. Based on the relationship that the bending temperature value is less than the bending evaluation temperature value, the bending process is stopped and preheating is performed again.

[0088] The initial bending speed is determined based on the bending angle. A CNC copper tube bending machine is used to bend the copper tube. During the bending process, a short-wave infrared thermal imager is used to obtain the bending temperature value. The bending temperature value is compared with the standard bending temperature value to determine the qualification of the bending conditions. If the bending temperature value is greater than or equal to the standard bending temperature value, the bending conditions are deemed qualified; if the bending temperature value is less than the standard bending temperature value, the bending conditions are deemed unqualified.

[0089] The standard bending temperature value is obtained through laboratory calibration based on the material properties and bending radius of the copper tube. During the bending process, if the bending temperature is too high, the copper tube still retains residual plasticity and heat energy activated by preheating. Preheating reduces stress, and the copper tube remains in a softened state. This reduces the deformation resistance during bending, lowers the yield strength, and increases elastic strain as the temperature decreases. At excessively high bending temperatures, the elastic strain is small (3.1-3.5 kN). Combined with the reduced deformation resistance, this results in less springback upon completion of the bending process. As the degree of bending deformation increases, the copper tube hardens and becomes brittle, leading to a large proliferation and entanglement of dislocations, hindering further deformation—a work hardening phenomenon. High-temperature activation, however, promotes cross-slip and climb dislocations, allowing them to bypass obstacles. The elements cancel each other out or rearrange to form a lower energy state, thereby suppressing work hardening and improving bending accuracy. However, if the bending temperature is too low, dislocation becomes difficult, increasing elastic strain and deformation resistance. After bending, the increased deformation resistance and elastic strain lead to increased springback in the bent copper tube. This increased springback exceeds expectations, reducing dimensional control accuracy. Therefore, when using nylon rods as the internal support material for the copper tube, a standard bending temperature of 70°C is used to determine the compliance of the bending conditions during the current bending process. For example, when bending a copper tube with a bending angle of 61°, the bending speed is 6° / s, while for a bending angle of 70°, the bending speed is 5° / s. If the bending angle is less than 60°, the bending speed is increased to 7° / s.

[0090] When the bending temperature value is greater than or equal to the bending standard temperature value, and the bending conditions are deemed qualified, the copper tube is bent at the initial bending speed, and the bending process can be completed according to the target state.

[0091] When the bending temperature value is less than the bending standard temperature value, the bending conditions are deemed unqualified, indicating that the current bending conditions are no longer sufficient for the copper tube to bend under the target conditions. In this case, it is necessary to further determine whether the bending conditions are out of control.

[0092] This invention monitors the bending temperature during the bending process to determine the compliance of the current bending conditions. The bending temperature affects the bending quality of the copper tube under the current bending process. Therefore, when all compliance judgments are unqualified and the current bending process is at risk, a bending evaluation parameter is constructed using a third deviation rate. This parameter comprehensively evaluates the bending quality of the copper tube from multiple dimensions and makes corresponding adjustments. Simultaneously, a deeper judgment is made regarding the bending temperature to determine whether the current bending temperature is out of control and can no longer meet the bending requirements. Thus, while comprehensively judging the compliance of the bending quality, the risk of continuing bending processing is assessed from a single perspective. This ensures that while comprehensively judging the bending quality, it avoids quality control failure due to a single dimension exceeding the bending requirements without timely warning, resulting in a decrease in bending efficiency and yield.

[0093] Specifically, in response to the determination that the bending conditions are unqualified, the bending temperature value is compared with the bending evaluation temperature value. If the bending temperature value is greater than or equal to the bending evaluation temperature value, it is determined that the bending conditions are not out of control. The bending quality is judged by constructing the bending evaluation parameters based on the third deviation rate determined by the bending temperature value being lower than the bending standard temperature value.

[0094] Compare the bending temperature value with the bending evaluation temperature value to determine whether the bending conditions are out of control; if the bending temperature value is greater than or equal to the bending evaluation temperature value, the bending conditions are not out of control; if the bending temperature value is less than the bending evaluation temperature value, the bending conditions are out of control.

[0095] The bending evaluation temperature value is determined based on the lower limit of the bending temperature range, which is 50°C. When the bending temperature value is greater than or equal to the bending evaluation temperature value, it is determined that the bending conditions are not out of control. At this time, although the bending process cannot be completed according to the target state, it is still in a state where the bending process can be carried out.

[0096] When the bending temperature value is less than the bending evaluation temperature value, and the bending conditions are determined to be out of control, if the bending process is still carried out, the bending effect may not reach the target state due to insufficient plasticity of the copper tube. Therefore, the bending process should be stopped; the copper tube should be reheated and cooled again before bending.

[0097] This invention further determines the uncontrollability of bending conditions when they are deemed unacceptable. If the bending conditions are not out of control, the bending quality of the copper tube during bending is comprehensively evaluated from multiple dimensions using bending evaluation parameters, and corresponding adjustments are made to automatically balance bending quality and efficiency. When the bending conditions are determined to be out of control, it indicates that the current bending conditions do not meet the requirements of bending processing, and the current bending process needs to be stopped, the copper tube reheated, and the bending process restarted after the plasticity is restored. This ensures the quality of copper tube bending and improves the yield rate of copper tubes.

[0098] Step S5: Based on the case where the actual temperature difference is greater than the preset temperature difference, or the radial pressure value does not belong to the preset pressure range, or the bending temperature value is less than the bending standard temperature value, bending evaluation parameters are constructed according to the first deviation rate, the second deviation rate, and the third deviation rate determined by the actual temperature difference exceeding the preset temperature difference to determine the qualification of bending quality. Based on the determination that the bending quality is unqualified, the subsequent bending speed is adjusted according to the excess value.

[0099] The excess value is determined based on the bending evaluation parameters and the preset evaluation parameters.

[0100] Specifically, the process of adjusting the subsequent bending speed based on the exceeded value includes,

[0101] By comparing the bending evaluation parameters with the preset evaluation parameters, if the bending evaluation parameters are greater than the preset evaluation parameters, the bending quality is determined to be unqualified. Based on the excess value and the current bending speed, the subsequent bending speed is adjusted to reduce the bending speed.

[0102] Compare the bending evaluation parameters with the preset evaluation parameters to determine the pass rate of bending quality; if the bending evaluation parameters are less than or equal to the preset evaluation parameters, the bending quality is deemed to be passable; if the bending evaluation parameters are greater than the preset evaluation parameters, the bending quality is deemed to be failable.

[0103] Let the bending evaluation parameter be W, the preset evaluation parameter be Wf, the first deviation rate be R, the second deviation rate be P, and the third deviation rate be Q, with corresponding weights Hi, Hj, and Hk, respectively. Hi, Hj, and Hk are assigned values ​​based on the degree of influence of the first deviation rate R, the second deviation rate P, and the third deviation rate Q on the bending quality. During the bending process, the bending temperature affects the deformation resistance of the copper tube during the current bending process, having the greatest impact on the bending quality; that is, the third deviation rate has the greatest impact on the bending quality. Hk has a maximum value of 0.5. The radial pressure affects whether wrinkles or plastic collapse occur during the bending process of the copper tube, having the second greatest impact on the bending quality; that is, the second deviation rate has the least impact on the bending quality. The influence of bending quality is secondary; therefore, Hj is set to 0.3. The actual temperature value corresponding to the actual temperature difference affects the recovery of the plastic properties of the copper tube. After heating the copper tube to the preheating temperature range of 500-600℃, the influence of the bending angle on the bending quality during the bending process is the weakest. Therefore, Hi is set to 0.2; and Hi+Hj+Hk=1.0. When bending copper tubes with other parameters, bending with different bending radii, or using other heating temperatures to restore the plastic properties of the copper tube, the weight values ​​can be re-determined based on the influence of the first deviation rate, the second deviation rate, and the third deviation rate on the bending evaluation parameters.

[0104] W = Hi × R + Kj × Hj × P + Kk × Hk × Q; where Kj and Kk are correction parameters that correct P and Q to the same order of magnitude as R, avoiding invalid data caused by order of magnitude deviation from affecting the determination of bending quality compliance; the value of Kj is usually 4-6, and 5 is taken here, while the value of Kk is 3-5, and 4 is taken here;

[0105] For example, if the current bending angle is 56°, the corresponding pressure range is 2.6-3.6kN; the preset pressure range is 2.9-3.3kN, the initial bending speed is 6° / s, the actual temperature difference is 15℃, the radial pressure is 2.8kN, and the bending temperature is 62℃, then W=0.2×R+5×0.3×P+4×0.5×Q=0.2×|15-10| / 10+5×0.3×|2.8-3.1| / 3.1+4×0.5×|62-70| / 70=0.2×0.5+5×0.3×0.0968+4×0.5×0.1143=0.1+0.15+0.23=0.48;

[0106] When the preset evaluation parameters are deemed unqualified based on the pass / fail criteria, the deviation rate of the actual temperature difference value relative to the median value of the preset temperature difference value, the deviation rate of the median value of the boundary of the preset pressure range and the boundary of the risk pressure range relative to the median value of the preset pressure range, and the deviation rate of the median value of the bending standard temperature value and the bending evaluation temperature value are determined; Wf=0.2×|15-10| / 10+5×0.3×|2.75-3.1| / 3.1+4×0.5×|60-70| / 70=0.2×0.5+5×0.3×0.1129+4×0.5×0.1429=0.1+0.17+0.29=0.56;

[0107] At this point, if the bending evaluation parameter is less than or equal to the preset evaluation parameter, the bending quality is deemed acceptable, indicating that the current bending quality is sufficient to bend the copper tube well and ensure the bending accuracy of the copper tube. Bending can then be performed at the current bending speed.

[0108] When the bending evaluation parameter exceeds the preset evaluation parameter, indicating that the bending quality is unqualified, it means that the current bending quality is insufficient to properly bend the copper tube, and the copper tube may have insufficient plasticity. It is necessary to adjust the subsequent bending speed based on the excess value of the bending evaluation parameter relative to the preset evaluation parameter and the current bending speed. For example, if the current bending evaluation parameter is 0.7 and the bending speed is 7° / s, then the adjusted bending speed = 7 × (1 - Kv × (0.7 - 0.56) / 0.56); where Kv is the speed adjustment coefficient, adjusting the excess rate corresponding to the range of the bending evaluation parameter exceeding the preset evaluation parameter to the current value of the bending speed. Matching the adjustment rate between the minimum and minimum values, the current Kv value range is 0.2-0.28. Taking 0.25 at this point, which is close to the middle value of the range, can ensure the stability of the bending speed adjustment, avoid excessively fast adjustment which would cause the copper tube bending speed to be too slow, affecting the bending efficiency, and also avoid the quality problems caused by insufficient plasticity of the copper tube due to excessively slow bending speed adjustment. Therefore, the adjusted bending speed = 7×(1-0.25×(0.7-0.56) / 0.56)=6.56° / s; by reducing the subsequent bending speed, it is ensured that the bending quality can be guaranteed even when the plasticity of the copper tube is reduced, and a high-quality copper tube finished product can be produced by bending.

[0109] This invention, when all conformity assessments fail, constructs bending evaluation parameters to comprehensively assess the bending quality of copper tubes. This allows for targeted adjustment of the bending speed when the bending quality is deemed unacceptable. This prevents situations where multiple directions of bending are out of control due to failed conformity assessments, without subsequent adjustments to the bending process, which could lead to a decline in bending quality and subsequent cracking or wrinkling during copper tube bending. Therefore, even when out of control is not identified, reducing the bending speed to compensate for insufficient bending quality ensures that the copper tube will not crack, wrinkle, or collapse during bending, thus improving the yield rate of bent copper tubes.

[0110] Specifically, based on the condition that the actual temperature difference is less than or equal to the preset temperature difference, the radial pressure value is within the preset pressure range, and the bending temperature value is greater than or equal to the bending standard temperature value, the runaway evaluation parameters are adjusted according to the preset adjustment amount. The runaway evaluation parameters include the risk temperature difference, the risk pressure range, and the bending evaluation temperature value.

[0111] Specifically, in response to adjusting the runaway evaluation parameters according to the preset adjustment amount, the control risk temperature difference value decreases, the control risk pressure range shrinks from both ends to the middle value, and the control bending evaluation temperature value increases.

[0112] The preset adjustment amount is an empirical value obtained after multiple bending processes of the copper tube. It can also be determined based on different yield rates during different bending processes using different copper tube parameters. The runaway assessment parameters include the risk temperature difference, risk pressure range, and bending assessment temperature. For example, if the current risk temperature difference is 20℃, the risk pressure range is 2.6-3.6kN, and the bending assessment temperature is 50℃, then the preset adjustment amount will be used to adjust the risk temperature difference to 19℃, the risk pressure range to 2.65-3.55kN, and the bending assessment temperature to 52℃. This makes the runaway assessment parameters more accurately suited to the current single runaway assessment of the copper tube, further improving the stability of the bending process and the consistency of the finished product. Single runaway includes heating runaway, support runaway, and bending condition runaway.

[0113] When all conformity assessments are satisfactory, this invention adjusts the runaway assessment parameters according to a preset adjustment amount. In the event of a single non-conformity assessment, it responds in advance to the single runaway assessment, thereby improving the accuracy of copper tube bending, ensuring automatic adjustment of parameters during the bending process, and further guaranteeing the quality and efficiency of copper tube bending.

[0114] 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 bending process for evaporator copper tubes based on automated adjustment, characterized in that, include, The actual surface temperature of the preheated copper tube at the end of heating is obtained to determine the actual temperature difference and the heating qualification. In response to the determination of heating failure, the bending angle during the bending process is adjusted according to the temperature difference deviation value, and the number of bending times is verified based on the determined bending angle. In response to the determination that the heating is unqualified, the preheating temperature of the copper tube in the subsequent bending process is adjusted; After the surface temperature of the copper tube drops to the bending temperature, the internal support material is installed with axial pressure determined according to the bending angle. The radial pressure value of the internal support material with radial deformation on the inner wall of the copper tube is obtained. The support failure is determined based on the radial pressure value to determine the axial pressure regulation state. During the bending process, the bending temperature value determined based on the surface temperature of the copper tube is used to determine the runaway of bending conditions in order to determine the bending process status. Based on the situation where the actual temperature difference is greater than the preset temperature difference, or the radial pressure value does not belong to the preset pressure range, or the bending temperature value is less than the bending standard temperature value, bending evaluation parameters are constructed according to the first deviation rate, the second deviation rate, and the third deviation rate determined by the actual temperature difference exceeding the preset temperature difference to determine the qualification of bending quality. In response to the determination that the bending quality is unqualified, the subsequent bending speed is adjusted according to the excess value. The process of controlling the bending angle during the bending process includes, Comparing the actual temperature difference with the preset temperature difference, if the actual temperature difference is greater than the preset temperature difference, the heating is deemed unqualified. The bending angle during the bending process is adjusted to reduce the temperature difference deviation. The temperature difference deviation is determined based on the difference between the actual temperature difference and the preset temperature difference. The actual temperature difference is determined based on the highest actual temperature value of the copper tube surface and the target temperature value. The process of verifying the number of bends based on a determined bending angle includes, Compare the bending angle with the preset bending angle range; if the bending angle is not within the preset bending angle range, determine that the number of bending times should be increased. The process of determining the axial pressure control state includes: By comparing the radial pressure value with the risk pressure range, if the radial pressure value does not fall within the risk pressure range, it is determined that the support has lost control. The direction of axial pressure adjustment is determined based on the deviation of the radial pressure value from the risk pressure range. The actual temperature difference value is determined based on the actual temperature value and the target temperature value, and the excess value is determined based on the bending evaluation parameters and the preset evaluation parameters.

2. The evaporator copper tube bending process based on automated adjustment according to claim 1, characterized in that, In response to the determination that the support is not out of control, the radial pressure value is compared with the preset pressure range. If the radial pressure value does not belong to the preset pressure range, the support is determined to be unqualified. The bending quality is determined by constructing a second deviation rate determined by the median value of the radial pressure value deviating from the preset pressure range.

3. The evaporator copper tube bending process based on automated adjustment according to claim 1, characterized in that, The process of determining the bending processing state includes: By comparing the bending temperature value with the bending standard temperature value, if the bending temperature value is less than the bending standard temperature value, the bending condition is deemed unqualified. Based on the relationship that the bending temperature value is less than the bending evaluation temperature value, the bending process is stopped and preheating is performed again.

4. The evaporator copper tube bending process based on automated adjustment according to claim 3, characterized in that, In response to the determination that the bending conditions are unqualified, the bending temperature value is compared with the bending evaluation temperature value. If the bending temperature value is greater than or equal to the bending evaluation temperature value, it is determined that the bending conditions are not out of control. The bending quality is judged by constructing the bending evaluation parameters based on the third deviation rate determined by the bending temperature value being lower than the bending standard temperature value.

5. The evaporator copper tube bending process based on automated adjustment according to claim 1, characterized in that, The process of adjusting the subsequent bending speed based on the exceeded value includes, By comparing the bending evaluation parameters with the preset evaluation parameters, if the bending evaluation parameters are greater than the preset evaluation parameters, the bending quality is determined to be unqualified. Based on the excess value and the current bending speed, the subsequent bending speed is adjusted to reduce the bending speed.

6. The evaporator copper tube bending process based on automated adjustment according to claim 1, characterized in that, Based on the condition that the actual temperature difference is less than or equal to the preset temperature difference, the radial pressure value is within the preset pressure range, and the bending temperature value is greater than or equal to the bending standard temperature value, the runaway evaluation parameters are adjusted according to the preset adjustment amount. The runaway evaluation parameters include the risk temperature difference, the risk pressure range, and the bending evaluation temperature value.

7. The evaporator copper tube bending process based on automated adjustment according to claim 1, characterized in that, In response to the controllability evaluation parameters adjusted according to the preset adjustment amount, the control risk temperature difference value decreases, the control risk pressure range shrinks from both ends to the middle value, and the control bending evaluation temperature value increases.

Images