A leak-proof sealing press forming process

Abstract

The application provides a leakage-proof sealing punch forming process, and the application collects pressure data of each region, controls pressure average F 高 , F 低 and α 唇 ; if α 唇 exceeds a predetermined threshold value, it indicates that the sealing lip edge has a pressure imbalance phenomenon (pressure anomaly), which may cause local sealing failure or excessive extrusion deformation, so whether the pressure average F 高 , F 低 is abnormal at this time can infer the specific reason causing the pressure imbalance phenomenon.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of stamping forming process, in particular to a kind of anti-leakage sealing stamping forming process. BACKGROUND

[0002] In the field of automobile manufacturing, the reliability of sunroof system directly affects the use experience and durability of the whole vehicle; In extreme rainfall weather, the good sealing performance of sunroof frame can effectively resist rainwater backflow and prevent the carpet, seat and other components in the vehicle from being mildewed and deformed due to water immersion; In the face of harsh road conditions ravaged by wind and sand, a tight sealing structure can prevent sand particles from entering and protect the precision electronic components in the vehicle from being worn out; Therefore, the sealing performance of sunroof frame directly affects the user experience.

[0003] The sealing lip (the position inside the sunroof frame border in the closed or semi-closed space formed between the sunroof frame and the glass assembly surface is the sealing lip) is the core structure of the sunroof frame to realize waterproof and dustproof function, and its performance stability is directly related to the sealing performance of the whole vehicle; However, in the actual production and manufacturing process, the sealing lip pressure anomaly problem occurs frequently, and the traditional detection method only focuses on monitoring the lip pressure value, which is difficult to accurately locate the abnormal source. For example, when the sunroof frame made of tailor-welded material is sealed and stamped, since the tailor-welded material is composed of high-strength steel and low-carbon steel, if the lip appears abnormal at this time, it may be due to the fact that the low-carbon steel material area bears excessive pressure during the stamping process and generates a conduction effect, or it may be due to the fact that the high-strength steel area lacks constraint ability due to unreasonable structure design or process parameters, thereby causing overall pressure imbalance, but the existing monitoring method cannot accurately and quickly determine the specific cause of the problem, so it is difficult to respond in time; Therefore, a sealing stamping forming process is needed to quickly identify and handle the sealing lip pressure anomaly of the tailor-welded material sunroof frame during the stamping process. SUMMARY

[0004] The purpose of the present application is to design a kind of anti-leakage sealing stamping forming process to solve the problems raised in the background art. To achieve the above purpose, the present application provides the following technical scheme: comprising the following steps:

[0005] Step 1, a plurality of pressure monitoring points are arranged in the high-strength steel border area, low-carbon steel intermediate area and sealing lip area of the tailor-welded plate of the sunroof frame, and the pressure data of each area are collected in real time and transmitted to the control module;

[0006] Step 2, the control module calculates the pressure mean value F 高 , the pressure mean value F 低 and the pressure variance 唇 of the high-strength steel border area, the low-carbon steel intermediate area and the sealing lip area respectively according to the pressure data of each area.

[0007] Step 3, the control module determines 唇 whether it is greater than a threshold value, when the determination result is no, return to step 2, and when the determination result is yes, further determine F 低 whether it is greater than a threshold value, when the determination result is yes, execute step 4, otherwise execute step 5;

[0008] Step 4, the control module controls the stamping pressure of the low carbon steel middle region to decrease by gradient, while monitoring the pressure variance of the sealing lip edge region until 唇 is less than a threshold value;

[0009] Step 5, the control module determines F 高 whether it is less than a threshold value, when the determination result is yes, the control module controls the stamping pressure of the high strength steel frame region to increase by gradient, while monitoring the pressure variance of the sealing lip edge region until 唇 is less than a threshold value; when the determination result is no, return to step 2.

[0010] Further, in step 5, the control module determines F 高 whether it is less than a threshold value, when the determination result is no, the control module will determine F 低 / F 高 whether its value is greater than a threshold value, when the determination result is no, enter step 2, when the determination result is yes, the control module decreases the stamping pressure of the low carbon steel middle region by gradient while increasing the stamping pressure of the high strength steel frame region by gradient, until F 低 / F 高 its value is less than a threshold value.

[0011] Further, in step 2, the control module also calculates the pressure variance of the high strength steel frame region 高 and the pressure variance of the low carbon steel middle region 低 respectively according to the pressure data of each region; the control module calculates the low carbon steel stability coefficient K 高 , F 低 , 高 and 低 respectively according to F 低 =F 低 / 低 and the high strength steel stability coefficient K 高 =F 高 / 高 ; if K 低 and K 高If the value of the pressure does not belong to the corresponding threshold interval, it is determined that the pressure in the middle area of the low carbon steel or the frame area of the high strength steel is abnormal, and an alarm is issued to stop the stamping operation.

[0012] Further, it further comprises step 6, in step 5, if the control module determines that F 高 is less than the threshold value, the determination result is no, and step 6 is entered,

[0013] Step 6, the stamping process of the sunroof frame tailor-welded plate is divided into a drawing stage, a bending stage and a shaping stage; the control module stores the pressure value in order of the stamping depth after monitoring the pressure of each stamping stage, and draws a curve F 拉 (s) of the pressure value changing with the depth. 弯 (s) and F 整 (s); and calculates the net pressure cumulative values of each stamping stage as I 拉 = , I 弯 = and I 整 = ; F 密 is the real-time pressure in the sealed cavity at the same period, the sealed cavity is a closed or semi-closed space formed between the sunroof frame and the glass assembly surface; the threshold interval (Z1, Z2) of the comprehensive net pressure cumulative detection parameter is pre-input in the control module, the control module calculates the comprehensive net pressure cumulative detection parameter Z = (I 拉 / 0.3 + I 弯 / 0.4 + I 整 / 0.3) / 3 according to I 拉 , I 弯 and I 整 ; and when it is judged that Z does not belong to the interval (Z1, Z2), the pressure cumulative abnormality determination mode is entered, and when it is judged that Z belongs to the interval (Z1, Z2), step 2 is returned.

[0014] Further, the standard net pressure cumulative value I0 in the complete stamping process is pre-input in the control module, so the pressure cumulative abnormality determination mode is:

[0015] If Z>Z2, and I 拉 >0.3I0, the control module reduces the stamping speed of the drawing stage by 10%-15%;

[0016] When Z<Z1, and I 整 <0.3I0, the control module increases the average pressure of the shaping stage by 5%-8%, reduces the shaping stage speed by 4%-6%, and at the same time prolongs the holding time of the shaping stage to 0.5-1.5 seconds.

[0017] Further, in step 6, the control module calculates the change rates d1=dI 拉 / ds, d2=dI 弯 / ds and d3=dI 整 / ds; when there is a change rate greater than the corresponding threshold, the control module stops the stamping operation while issuing an alarm.

[0018] Further, in step 4, the control module pauses for 0.5-1 second every time the stamping pressure of the low-carbon steel intermediate region is reduced by 10 kN in a gradient manner.

[0019] Compared with the prior art, the present application has the following advantages: the present application collects pressure data of each region, and controls the pressure mean value F 高 , F 低 and 唇 of each region through the control module, so that the pressure of each region can be balanced. 唇 If the pressure mean value F 高 , F 低 exceeds the predetermined threshold, it indicates that there is an unbalanced pressure phenomenon (abnormal pressure) in the sealing lip, which may cause local sealing failure or excessive extrusion deformation, so that the specific cause of the unbalanced pressure phenomenon can be inferred by re-determining whether the pressure mean value F 高 , F 低 is abnormal. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0021] Figure 1 The present application is a stamping flowchart. DETAILED DESCRIPTION

[0022] In order to further illustrate the technical means and effects adopted by the present application to achieve the predetermined application purposes, the following will describe the specific embodiments, structures, features and effects of the present application in detail in combination with the drawings and preferred embodiments.

[0023] With the development of automobile lightweight technology, and because the tailor-welded material is composed of plates with different strength, thickness and material, it can achieve weight reduction while meeting the structural performance requirements, so the application of tailor-welded material in automobile sunroof frame stamping parts is becoming more and more widely. When the sunroof frame made of tailor-welded material is sealed and stamped, because the characteristics of each plate in the tailor-welded plate are different, and the plate thickness is also different, the stamping requirements (such as forming force, punch and die gap, stretching amount) of different areas in the tailor-welded plate are also different. Therefore, in order to ensure the forming precision of the sunroof frame made of tailor-welded material and improve the product quality, a multi-stage stamping form can be used for the sunroof frame by using a block mold. The forming part of the mold is divided into multiple independent modules by the block mold, each module corresponds to a "homogeneous area" (such as a certain high-strength steel area or a certain thin plate area) of the tailor-welded plate, and the parameters such as the cutting edge, the round corner and the gap are designed respectively to avoid local cracking, wrinkling or excessive deformation caused by the "one-size-fits-all" whole mold.

[0024] Although the use of block molds can improve the forming precision of the sunroof frame made of tailor-welded material, the stamping quality of the sealing lip (the position inside the sunroof frame frame in the closed or semi-closed space formed between the sunroof frame and the glass assembly surface is the sealing lip) is particularly important for the sunroof frame which has high sealing performance. However, when using a block mold for stamping, the stamping parameters of each area are different, such as the stamping speed and the stamping pressure of each area, which can easily cause different pressures in different areas of the sealing lip, leading to frequent abnormal pressure of the sealing lip and affecting the stamping quality of the sealing lip. Therefore, timely detection and determination of abnormal pressure of the sealing lip is particularly important.

[0025] However, the traditional detection method only focuses on monitoring the pressure value of the lip, and it is difficult to accurately locate the root cause of the abnormality. For example, when the sunroof frame made of tailor-welded material is sealed and stamped, because the tailor-welded material is composed of high-strength steel and low-strength steel, if the lip pressure is abnormal at this time, it may be due to the low-carbon steel material area bearing excessive pressure and producing a conduction effect during the stamping process, or it may be due to the high-strength steel area having insufficient constraint ability due to unreasonable structure design or process parameters, thereby causing overall pressure imbalance. However, the existing monitoring method cannot accurately and quickly determine the specific cause of the problem, making it difficult to respond in a timely manner.

[0026] In this embodiment, please refer to Figure 1 , a leak-proof sealing and stamping forming process is disclosed, comprising the following steps:

[0027] Step 1, arranging a plurality of pressure monitoring points in the high-strength steel frame area, low-carbon steel intermediate area and sealing lip area of the tailor-welded plate of the sunroof frame, collecting real-time pressure data of each area and transmitting them to the control module.

[0028] Step 2, the control module calculates the pressure mean value F of the high-strength steel frame area according to the pressure data of each area 高 , the pressure mean value F of the low-carbon steel middle area 低 , and the pressure variance of the sealing lip area 唇 ; wherein, 唇 As a key indicator for measuring the pressure dispersion degree of the sealing lip area of the tailor-welded blank sunroof frame, the numerical value directly reflects the fluctuation of the pressure at different measurement points or time periods. If the variance value exceeds the predetermined threshold, it indicates that there is an imbalance in the pressure of the sealing lip area (pressure anomaly), which may cause local sealing failure or excessive extrusion deformation. Therefore, at this time, other parameters can be combined for collaborative analysis and positioning of the abnormal source;

[0029] Step 3, the control module determines 唇 whether it is greater than the threshold value, and when the determination result is yes, it is preliminarily determined that there is an abnormal pressure in the sealing lip area. Then the control module further determines whether F 低 is greater than the threshold value, and when the determination result is yes, it indicates that the sealing lip pressure anomaly is caused by excessive pressure effect in the low-carbon steel area, which is prone to cause the sealing lip to bulge. At this time, the control module controls the stamping pressure of the low-carbon steel middle area to decrease by gradient in step 4, and the stamping pressure is paused for 0.5-1 second every time it decreases by 10 kN to ensure the stability of the stamping quality, until the pressure variance of the sealing lip area 唇 is less than the threshold value; if F 低 is less than the threshold value, step 5 is entered;

[0030] Step 5, the control module determines whether F 高 is less than the threshold value, and when the determination result is yes, it indicates that the sealing lip pressure anomaly is caused by insufficient pressure effect in the high-strength steel area, which is prone to cause the sealing lip to rebound. At this time, the control module controls the stamping pressure of the high-strength steel frame area to increase by gradient, while reducing the stamping speed to prolong the pressure action time, until 唇 is less than the threshold value. In this process, the temperature control method can also be started to heat the high-strength steel area, reducing the required stamping pressure and reducing the occurrence of sealing lip rebound phenomenon.

[0031] Although the above method can prevent the sealing lip from bulging or rebounding, the problem of the sealing lip is not only these two phenomena, but also the phenomenon of the sealing lip being twisted. Therefore, when F 低 is less than the threshold value and F 高When the value exceeds the threshold, the occurrence of bulging and rebound issues is ruled out; subsequently, the control module will determine F. 低 / F 高 If the value is greater than the threshold, and the result is yes, it indicates a severe imbalance in the pressure distribution between the high-strength steel frame area and the low-carbon steel middle area. This can cause the sealing lip to twist. At this time, the control module gradually decreases the stamping pressure of the low-carbon steel middle area while gradually increasing the stamping pressure of the high-strength steel frame area until F... 低 / F 高 The value is less than the threshold, which makes the pressure distribution between the high-strength steel frame area and the low-carbon steel middle area more balanced, preventing the sealing lip from twisting.

[0032] In step 2, the control module also calculates the pressure variance of the high-strength steel frame area based on the pressure data of each area. 高 Pressure variance in the intermediate region between low carbon steel 低 The control module uses F 高 F 低 , 高 and 低 Calculate the stability coefficient K of low carbon steel respectively 低 =F 低 / 低 and the stability coefficient K of high-strength steel 高 =F 高 / 高 If K 低 and K 高 If the value is not within the corresponding threshold range, it is determined that the pressure in the middle area of ​​low-carbon steel or the frame area of ​​high-strength steel is abnormal, and an alarm is issued while the stamping operation is stopped; where K 低 and K 高 It reflects the material's sensitivity to pressure changes. If K 低 and K 高 Too large: means F 高 and F 低 relatively 高 and 低 A pressure setpoint that is too high, meaning a high average pressure but a small fluctuation range, indicates that the material is under overpressure. This could lead to excessive deformation of the sealing lip, shortened fatigue life, or even plastic deformation failure. Therefore, in this case, the pressure setpoint should be reduced, and the pressure control algorithm should be optimized to enhance the dynamic response capability to pressure fluctuations. If K 低 and K 高 Too small: means F高 and F 低 relative 高 and 低 Too small, that is, the average pressure is low but the fluctuation is violent, which may cause the sealing lip to fit loosely, causing sealing failure, so at this time the average pressure should be increased, and the damping of the pressure control system should be increased to suppress abnormal fluctuations, thereby further improving the detection of abnormal stamping of the sealing lip during the stamping process and making appropriate response methods, thereby improving the sealing stamping quality of the sunroof frame using the tailor-welded material.

[0033] If F 低 is less than the threshold value, F 高 is greater than the threshold value, F 低 / F 高 is less than the threshold value, and K 低 and K 高 are within the threshold value range, it means that during the stamping process, the short-term stamping process does not cause obvious stamping abnormalities to the sealing lip; but this cannot completely determine that the sealing lip after stamping is free of defects; because the plastic deformation of low-carbon steel and high-strength steel in tailor-welded plates is not only related to "instantaneous pressure" but also related to "pressure action time (or stroke)", for example, under normal circumstances, the stamping process of the tailor-welded plate of the sunroof frame is divided into three stages: the drawing stage, the bending stage and the shaping stage: in the drawing stage, if the instantaneous pressure is always within the qualified range, but the action time is too long (the stroke is too large), it will cause "overstretching" of the material. This cumulative effect cannot be reflected by the mean value (the average pressure at a certain moment) or the variance (the degree of pressure fluctuation), and it is found through experiments that when the above-mentioned situation occurs, it will cause the phenomenon of delayed bulging of the sealing lip after 24 hours (the bulging of the lip at the time of stamping is ≤0.05mm, but the bulging height increases ≥0.03mm after 24 hours (natural aging)), thereby causing product defects; and in the shaping stage, even if the instantaneous pressure is qualified, but if the action time is insufficient (the stroke is too short), the cumulative pressure cannot offset the elastic recovery trend of the material, which will cause "aging springback" (the rebound amount exceeds the tolerance within 30 days) after the lip is assembled, and the use of stroke alone has greater limitations because the pressure is the main factor causing abnormalities; in summary, the use of pressure or stroke alone cannot fully reflect the long-term impact of mold pressure on tailor-welded plates during stamping, so it is necessary to combine "pressure size" and "action stroke" to quantify this "time-dependent deformation";

[0034] Therefore, in the present embodiment, step 6 is also included, that is, after the control module monitors the pressure of each stamping stage, the pressure values are stored in order of stamping depth, and a curve F 拉 (s) is drawn. 弯 (s) and F整 (s), and calculate the cumulative net pressure value for each stamping stage as I 拉 = I 弯 = and I 整 = This integral process reflects the total "energy input" to the plastic deformation of the material at each stage, F 密 The pressure inside the sealed cavity is the real-time pressure (this pressure is not directly applied to the stamping pressure of the material forming, so the interference of the sealing pressure on the stamping needs to be deducted to eliminate the influence of this non-stamping forming core force, ensuring that the calculated integrals of each stage such as the drawing stage, bending stage, and forming stage can accurately reflect the effective forming pressure of the material during the actual stamping process, thereby improving the accuracy of the abnormal pressure judgment of the sealing lip, avoiding misjudgment of the stamping state due to irrelevant pressure interference, thus demonstrating the accuracy of this judgment method compared to conventional detection, and more effectively reflecting the long-term influence of the die pressure on the welded plate during the stamping process). The sealed cavity is the closed or semi-closed space formed between the sunroof frame and the glass assembly surface.

[0035] The control module has a pre-input threshold range (Z1, Z2) for the comprehensive net pressure accumulation detection parameters. The control module then calculates the threshold range based on I. 拉 I 弯 and I 整 Calculate the cumulative net pressure detection parameter Z = (I 拉 / 0.3+I 弯 / 0.4+I 整 / 0.3) / 3, where, under ideal conditions (i.e., the stamping quality of the sealing lip is qualified), I 拉 / 0.3=I 弯 / 0.4=I 整 / 0.3, 0.3, 0.4 and 0.3 are the weighting coefficients of each stamping stage on the stamping quality of the sealing lip, which are used to quantify the differences in the contribution of different stamping stages to the final quality of the sealing lip and avoid the judgment bias caused by treating the integrals of each stage equally; therefore, the weighting is matched with the function of each stage according to the differences in the effect of different stamping stages on lip forming.

[0036] Since the stretching stage is the key link in the formation of the lip fold angle, the angle accuracy and flatness of the fold angle directly determine the sealing fit with the glass (experimental data shows that a 10% pressure fluctuation in the bending section will cause the lip flatness to exceed the tolerance by 0.08 mm, accounting for 45% of the total defects). Therefore, this weight accounts for a relatively large proportion. The main function of the drawing stage is to stretch the material to form the basic contour of the lip. If the integral is excessive, it will cause bulging in the later stage, but the impact on the sealing performance of the lip is weaker than that of the bending section. The shaping stage is used to lock the shape of the lip. If the integral is insufficient, it will cause springback, but the springback is mostly age deformation (within 30 days), and the impact on the sealing performance of the lip is also weaker than that of the bending section. Therefore, the weights of the shaping stage and the drawing stage are lower than that of the drawing stage. After experiments with controlled variables, the weights of the drawing stage, the bending stage, and the shaping stage are finally taken as 0.3, 0.4, and 0.3 respectively. At this time (I 拉 / 0.3 + I 弯 / 0.4 + I 整 / 0.3) / 3 is expressed as the comprehensive net pressure cumulative detection parameter. It can not only reflect the long-term impact of the die on the tailor-welded blank during the entire stamping process, but also compared with the common accumulation. This formula combines pressure and stroke. It not only adopts the cumulative effect of integration, but also considers the contribution differences of different stamping stages to the final quality of the sealing lip, avoiding the judgment deviation caused by treating the integrals of each stage equally, and greatly improving the accuracy of the abnormal judgment of the sealing lip;

[0037] When the control module determines that Z does not belong to the interval (Z1, Z2), it will enter the determination mode of abnormal pressure accumulation. If Z > Z2, since overpressure has a greater impact on the stretching stage, the control module will determine whether I 拉 > 0.3I0 holds. If it does, it means that there will be a problem of bulging in the later stage of the sealing lip. At this time, the control module adopts "segmented pressure compensation". That is, the pressure in the first 50% of the stroke in the drawing stage is reduced by 10%, and the pressure remains unchanged in the latter 50% of the stroke, ensuring that the total integral drops to the target value and the overall average pressure is still within the threshold range. Second, the drawing stage is reduced by 10% - 15%. By extending the stroke time, the pressure input per unit time is reduced to further suppress the excessive integral (experiments have proved that the reduction in speed and the reduction in integral are linearly related. For every 5% reduction in speed, the integral can be reduced by about 4%). Then, the lip bulge can be detected (it needs to meet ≤ 0.05 mm, otherwise continue to adjust to prevent the problem of bulge generation), and the size change after 24 hours is tracked to ensure that the bulge increment ≤ 0.03 mm. The detection of the bulge can be monitored by a laser profiler;

[0038] When Z < Z1, since underpressure has a greater impact on the shaping stage, the control module will determine I 整<0.3I0 is established, which indicates that it will cause the aging rebound problem when the sealing lip is formed. At this time, the control module is used to ensure that the average pressure is within the threshold range while increasing the average pressure of the shaping stage by 5-8%, reducing the shaping stage speed by 4-6%, and prolonging the shaping stage pressure maintaining time to 0.5-1.5 seconds. In addition, if it is judged that Z belongs to the interval (Z1, Z2), it indicates that there will be no aging rebound and late bulging problems.

[0039] The standard net pressure cumulative value I0 in the complete stamping process is input in advance in the control module, and the control module calculates the change rates d1=dI 拉 / ds, d2=dI 弯 / ds and d3=dI 整 / ds in real time. When the change rate is greater than the corresponding threshold value, the control module issues an alarm and stops the stamping operation. For example, when d2 is greater than the corresponding threshold value (usually set to 15% fluctuation), it indicates that the pressure accumulation in the bending stage is unstable, which can cause corner deformation. Therefore, in order to eliminate the shape abnormalities caused by instantaneous jumps, one is to arrange high-frequency pressure sensors (sampling frequency 1 kHz) in the bending segment mold. When the integral instantaneous jump is detected to be greater than 10%, the servo hydraulic valve group is immediately triggered to adjust: when the jump is positive, the local pressure is reduced by 8%, and when the jump is negative, the local pressure is increased by 10%, ensuring that I 弯 fluctuation is controlled within 8%; two is to add a 0.5mm thick elastic compensation block (material 65Mn spring steel) at the bending corner, which can absorb ±5% pressure fluctuation through elastic deformation, and optimize the mold guide mechanism to reduce the sliding friction coefficient from 0.12 to 0.08 (by spraying molybdenum disulfide coating), reducing the integral fluctuation caused by mechanical vibration; three is to reduce the bending segment stamping speed by 15-20% (such as from 1.0m / s to 0.8-0.85m / s), reducing material inertia impact; simultaneously using "progressive blank holder force" (such as increasing from initial 20kN to 30kN linearly), avoiding uneven material flow caused by sudden pressure change, thereby stabilizing the pressure accumulation in the stamping process, reducing the flatness at the corner, and eliminating the shape abnormalities caused by instantaneous jumps.

[0040] In summary, in the embodiment, the sunroof frame of the tailor-welded material only needs to collect the pressure values of each region in real time, and then the root cause of the pressure abnormality of the sealing lip in the sunroof frame during the stamping process can be accurately detected through the entire detection process in the application, and measures to effectively eliminate the pressure abnormality of the sealing lip can be taken, adjustment parameters for subsequent stamping are provided, and the stamping quality of the subsequent sunroof frame is ensured. At the same time, the wear of the die can also be predicted, thereby comprehensively improving the stamping quality of the sealing lip in the sunroof frame of the tailor-welded material when the die is stamped.

[0041] It should be noted that when an element is referred to as being "on" another element, it can be directly on the other element or intervening elements can also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements can also be present. As used herein, the terms "on", "above", "under", "below", "left", "right", "front", "rear", and the like are used for explanation purposes only and are not intended to be limiting.

[0042] The above description is only the preferred embodiment of the present application, and is not intended to limit the present application in any form. Although the present application has been disclosed as above with the preferred embodiment, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above disclosed technical content to obtain equivalent embodiments with equivalent changes, without departing from the technical solution of the present application. Any modification, change, equivalent change and modification of the above embodiments, which does not depart from the technical solution of the present application, is still within the scope of the present application.

Claims

1. A leak resistant, sealed, press forming process characterized by, The method comprises the following steps: Step 1, arranging a plurality of pressure monitoring points in the high-strength steel frame area, the low-carbon steel middle area and the sealing lip area of the sunroof frame tailor-welded blank respectively, collecting the pressure data of each area in real time and transmitting the pressure data to the control module; Step 2, the control module calculates the pressure average F of the high-strength steel frame area according to the pressure data of each area 高 , the pressure average F of the low-carbon steel middle area 低 , and the pressure variance of the sealing lip area 唇 ; Step 3, control module decision 唇 whether greater than threshold, when the decision is no, return to step 2, when the decision is yes, further decision F 低 whether greater than threshold, decision is yes, execute step 4, otherwise execute step 5; Step 4, the control module controls the stamping pressure of the low carbon steel middle region to decrease in gradient, and monitors the pressure variance of the sealing lip edge region until 唇 less than a threshold value; Step 5, control module determines F 高 whether less than a threshold value, when the determination result is yes, the control module controls the stamping pressure of the high-strength steel frame area to increase by gradient, and monitors the pressure variance of the sealing lip edge area until 唇 less than a threshold value; when the determination result is no, return to step 2.

2. The leak resistant, sealed, press-molding process of claim 1, wherein, In step 5, the control module determines whether F 高 is less than a threshold value. When the determination result is no, the control module determines whether the value of F 低 / F 高 is greater than a threshold value. When the determination result is no, the process proceeds to step 2. When the determination result is yes, the control module gradually decreases the press pressure in the low carbon steel intermediate region while gradually increasing the press pressure in the high strength steel frame region until the value of F 低 / F 高 is less than a threshold value.

3. The leak resistant, sealed, press-molding process of claim 2, wherein, In step 2, the control module also calculates the pressure variance of the high-strength steel frame area based on the pressure data of each area. 高 Pressure variance in the intermediate region with low carbon steel 低 The control module uses F 高 F 低 , 高 and 低 Calculate the stability coefficient K of low carbon steel respectively 低 =F 低 / 低 and the stability coefficient K of high-strength steel 高 =F 高 / 高 If K 低 and K 高 If the value is not within the corresponding threshold range, it is determined that the pressure in the middle area of ​​low-carbon steel or the frame area of ​​high-strength steel is abnormal, and an alarm is issued while the stamping operation is stopped.

4. The leak resistant seal press forming process of claim 1, wherein, Also included is Step 6, in Step 5, if the control module determines that F 高 is less than the threshold, the determination result is no, then go to Step 6, Step 6, the stamping process of the sunroof frame tailor-welded plate is divided into a drawing stage, a bending stage and a shaping stage; the control module stores the pressure values in order of the stamping depth after monitoring the pressure of each stamping stage, and draws a curve F of the pressure value changing with the depth 拉 (s), F 弯 (s) and F 整 (s); and calculates the net pressure cumulative values of each stamping stage as I 拉 = , I 弯 = and I 整 = ; F 密 is the real-time pressure in the sealed cavity at the same period, the sealed cavity being a closed or semi-closed space formed between the sunroof frame and the glass assembly surface; the control module has a threshold interval (Z1, Z2) of the comprehensive net pressure cumulative detection parameter pre-input in the control module; the control module calculates a comprehensive net pressure cumulative detection parameter Z = (I 拉 / 0.3 + I 弯 / 0.4 + I 整 / 0.3) / 3 according to I 拉 , I 弯 and I 整 ; and when it is judged that Z does not belong to the interval (Z1, Z2), the pressure cumulative abnormality judgment mode is entered, and when it is judged that Z belongs to the interval (Z1, Z2), step 2 is returned to.

5. The leak resistant, sealed, press-molding process of claim 4, wherein, The standard net pressure cumulative value I0 in the complete stamping process is inputted in the control module in advance, so the pressure cumulative abnormality judgment mode is: If Z > Z2, and I 拉 When I0> 0.3I0, the control module reduces the stamping speed of the drawing stage by 10-15%. When Z < Z1, and I 整 When 0.3 < I0 < 0.5, the control module increases the average pressure of the shaping stage by 5-8%, reduces the shaping stage speed by 4-6%, and prolongs the pressure maintaining time of the shaping stage to 0.5-1.5 seconds.

6. The leak resistant, sealed, press-molding process of claim 5, wherein, In step 6, the control module calculates the change rates dl = dl / ds, d2 = dl / ds and d3 = dl / ds of the drawing stage, the bending stage and the shaping stage 拉 respectively; when there is a change rate greater than the corresponding threshold, the control module issues an alarm while stopping the stamping operation. 弯 respectively; when there is a change rate greater than the corresponding threshold, the control module issues an alarm while stopping the stamping operation. 整 respectively; when there is a change rate greater than the corresponding threshold, the control module issues an alarm while stopping the stamping operation.

7. The leak resistant seal press forming process of claim 1, wherein, In step 4, the control module pauses for 0.5-1 seconds every time the stamping pressure of the low-carbon steel middle area is reduced by 10 kN.

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