A method for controlling the quality of forming of a hydraulic bulging test piece

Abstract

The application discloses a kind of hydraulic bulging test piece forming quality control method, comprising the following steps: setting the bulging information and initial bulging information of standard test piece;Utilize the bulging information of standard test piece and the initial bulging information, based on mold, obtain the bulging test piece of standard morphology, the mold is the composite mold of toughened glass and diamond;Based on the mold, the bulging test piece of standard morphology is detected, and based on the bulging information of standard test piece, the control of hydraulic bulging test piece forming quality is realized.The application determines the bulging distance by calculating the light propagation time in air, the toughened glass propagation time and the diamond propagation time, and obtains the bulging height and axial feed amount in this way, which can observe the bulging height of the test piece in real time, master the bulging condition, so as to realize quality control.

Description

Technical Field

[0001] This invention belongs to the field of project quality control, and in particular relates to a method for quality control of hydraulic bulging specimen forming. Background Technology

[0002] Tube hydroforming is an advanced plastic forming technology that achieves lightweight component structures and responds to energy conservation, emission reduction, and sustainable development policies. Its products offer the advantages of high quality and precision while also being lightweight and high-strength. However, due to the influence of the mold during the bulging process, the entire tube bulging process cannot be observed, and the pressure curve is usually set before bulging. Furthermore, current methods for controlling the quality of hydraulically bulged specimens primarily rely on experience and preliminary experiments to obtain suitable bulging pressure loading curves and axial feed speeds, which cannot be adjusted in real-time during the bulging process.

[0003] Therefore, this invention proposes a method for quality control of hydraulic bulging specimen forming to address the shortcomings of existing technologies. Summary of the Invention

[0004] The purpose of this invention is to propose a method for quality control of hydraulic bulging specimen forming, which can detect the bulging height in real time, understand the bulging situation, and thus achieve quality control.

[0005] To achieve the above objectives, this invention provides a method for quality control of hydraulic bulging specimen forming, comprising the following steps:

[0006] Set the bulging information and initial bulging information of the standard specimen;

[0007] Using the bulging information of the standard specimen and the initial bulging information, a standard bulging specimen is obtained based on a mold, wherein the mold is a composite mold of tempered glass and diamond.

[0008] The mold is used to test the standard bulging specimen, and the bulging information of the standard specimen is used to control the forming quality of the hydraulic bulging specimen.

[0009] Optionally, the bulging information of the standard specimen includes standard bulging dimensions, standard bulging height, bulging curve limit points, maximum allowable wrinkling height, and standard bulging specimen thickness.

[0010] Optionally, the initial bulging information includes axial feed pressure, axial feed speed, axial feed distance, bulging fluid pressure loading curve, and bulging fluid pressure.

[0011] Optionally, using the bulging information of the standard specimen and the initial bulging information, obtaining the bulging specimen of the standard shape based on the mold includes:

[0012] The axial feed pressure and the expansion fluid pressure are applied to the initial specimen to obtain a pressurized expansion specimen.

[0013] The height of the bulging specimen under pressure is obtained by measuring the pressure through the mold using an infrared measuring instrument.

[0014] Based on the height of the bulging specimen under pressure and the bulging information of the standard specimen, a bulging specimen with a standard shape is obtained.

[0015] Optionally, based on the height of the bulging specimen under pressure and the bulging information of the standard specimen, obtaining the bulging specimen of the standard shape includes:

[0016] The height of the bulging specimen under pressure is compared with the standard bulging height.

[0017] When the height of the pressurized bulging specimen is lower than the standard bulging height, the bulging fluid pressure and the axial feed distance are increased until the height of the pressurized bulging specimen reaches the limit point of the bulging curve, and the standard bulging specimen is obtained.

[0018] When the height of the bulging specimen under pressure is higher than the standard bulging height, the axial feed speed and the axial feed distance are reduced until the height of the bulging specimen under pressure, the limiting point of the bulging curve, and the maximum allowable wrinkling height meet the bulging information of the standard specimen, and the standard shaped bulging specimen is obtained.

[0019] Optionally, the composite mold of tempered glass and diamond specifically includes: the interior of the composite mold is made of tempered glass, and the exterior of the tempered glass is coated with diamond.

[0020] Optionally, the process of testing the standard-shaped bulging specimen based on the mold, and controlling the forming quality of the hydraulically bulging specimen based on the bulging information of the standard specimen, includes:

[0021] The thickness of the standard-shaped bulging specimen is obtained by using an ultrasonic thickness gauge through the mold.

[0022] The thickness of the standard bulging specimen is compared with the thickness of the standard bulging specimen to obtain a standard bulging specimen, thereby controlling the forming quality of the hydraulic bulging specimen.

[0023] Optionally, the thickness of the standard bulging specimen is compared with the thickness of the standard bulging specimen to obtain the standard bulging specimen, which includes:

[0024] If the thickness of the bulging specimen in the standard form does not meet the standard bulging specimen thickness, then the bulging specimen is a defective piece.

[0025] If the thickness of the bulging specimen of the standard shape meets the thickness of the standard bulging specimen, then the bulging specimen is the standard bulging specimen.

[0026] The present invention has the following beneficial effects:

[0027] This invention utilizes a measurement module comprised of a mold and a measuring unit to measure the bulging height and morphology of the specimen in real time, providing feedback data for adjusting hydraulic pressure and feed rate. The combination of diamond coating and tempered glass achieves the required hardness for the bulging mold while its good light transmittance allows measurement units such as infrared or laser sensors to penetrate and measure the morphology of the specimen within the mold. Tempered glass, also with good light transmittance, forms the overall shape of the mold, enabling its positioning. The distance to the bulging part is determined by calculating the light propagation time in air, tempered glass, and diamond. This method allows for the acquisition of bulging height and axial feed rate, and also enables real-time observation of the bulging height and monitoring of the bulging process, thus facilitating quality control. Attached Figure Description

[0028] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0029] Figure 1 This is a schematic flowchart of a hydraulic bulging specimen forming quality control method according to an embodiment of the present invention;

[0030] Figure 2 This is a schematic diagram of the mold proposed in an embodiment of the present invention. Detailed Implementation

[0031] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0032] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0033] like Figure 1 As shown, this embodiment provides a method for controlling the forming quality of hydraulically bulging specimens, specifically including the following steps:

[0034] Set the bulging information and initial bulging information of the standard specimen;

[0035] Using the bulging information and initial bulging information of standard specimens, standard bulging specimens are obtained based on a mold, which is a composite mold of tempered glass and diamond.

[0036] The mold is used to test the bulging test piece of the standard shape, and the bulging information of the standard test piece is used to control the forming quality of the hydraulic bulging test piece.

[0037] First, the desired formed part is set manually. This part information includes the bulging part dimensions, bulging height, bulging curve limit points, maximum allowable wrinkling height, and part thickness. Initial bulging parameters also need to be obtained, including axial feed pressure, axial feed speed, axial feed distance, bulging hydraulic pressure loading curve, and bulging hydraulic pressure. The bulging curve limit points serve as the desired values ​​for the control system; coincidence of bulging detection points indicates that the bulging height and shape meet the requirements.

[0038] This embodiment mainly consists of three parts: a hydraulic control section, a thickness measurement section, and a distance measurement section. The thickness and distance measurement sections use measuring devices that can transmit light through glass and diamond, such as infrared, ultrasonic, or DIC digital measuring devices.

[0039] Utilizing the light transmittance of a tempered glass composite mold coated with a certain thickness of diamond, such as... Figure 2 As shown, the interior is reinforced with tempered glass 2, and the top, bottom, front, and back outer layers are coated with diamond 1, ensuring that only diamond 1 is in contact with the specimen 3, thus guaranteeing sufficient mold strength. Then, an infrared sensor installed at a certain distance from the specimen is used to measure the bulging height and axial shrinkage of the pipe during the hydraulic bulging process through the composite mold. An ultrasonic ranging module installed at a certain distance from the specimen is used to measure the thickness of the pipe during the hydraulic bulging process through the composite mold, thereby constructing the state of the specimen forming process. The distances of the ultrasonic thickness measuring module and the infrared ranging module are determined after considering their fixed heights at the diamond and tempered glass, as well as the propagation speeds of ultrasonic and infrared rays. Simultaneously, measuring devices are installed on both sides of the mold to construct the entire bulging process of the specimen, achieving quality control for irregularly bulged parts.

[0040] During hydraulic bulging, a mold is typically required to obtain a part of a specific shape. The axial feed rate of the applied hydraulic loading curve is also determined in advance. This embodiment uses a measurement module composed of a mold and a measuring unit to monitor the bulging height and shape of the specimen in real time, providing feedback data for adjusting the hydraulic pressure and feed rate. Typically, the measuring unit cannot directly measure the bulging specimen during the forming process. In this embodiment, the mold combines diamond coating with tempered glass. Diamond is the hardest material in nature and can be formed under high temperature and pressure. Therefore, using diamond in the part in contact with the specimen achieves the hardness required for the bulging mold. Furthermore, its good light transmittance allows it to be penetrated by infrared or laser measuring units to measure the shape of the specimen inside the mold. However, diamond cannot currently be formed into particularly large pieces. Therefore, the main body can be made of tempered glass, which also has good light transmittance, serving as the overall shape of the mold and enabling mold positioning. Laser ranging generally works by emitting light and then receiving it, determining the distance by calculating the time it takes for the light to travel. In this embodiment, since the speed of light varies in different media, the distance to the bulging component is determined by calculating the propagation time of light in air, tempered glass, and diamond. In this way, the bulging height and axial feed can be obtained, and the bulging height of the specimen can also be observed.

[0041] Based on the initial bulging parameters, bulging begins, resulting in an arch in the middle. The bulging height is then monitored, specifically by measuring wrinkles that appear during the bulging process using an infrared sensor. The bulging curve limit points and the maximum allowable wrinkle height are checked to ensure they meet requirements. If the bulging height is insufficient, the bulging hydraulic pressure and axial feed distance are increased from the initial hydraulic pressure until the bulging height at all limit points reaches the bulging curve limit points. At this point, the hydraulic pressure is released, and the specimen is formed. If wrinkles occur, and the wrinkle height exceeds the maximum allowable wrinkle height, the feed speed and feed distance are reduced until the bulging height, bulging curve limit points, and maximum allowable wrinkle height all meet requirements, indicating that forming is complete. An ultrasonic thickness gauge is then used to inspect the thickness of the formed specimen to check if it meets the standard thickness. This avoids the influence of the stamping liquid during bulging on the ultrasonic waves and prevents wrinkled, insufficient bulging height, or insufficient thickness from appearing in the finished product. If the requirements are met, the process is complete; otherwise, it is a reject. Any failure to meet any intermediate parameter constitutes a rejection.

[0042] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for quality control of hydraulic bulging specimen forming, characterized in that, Includes the following steps: The standard specimen's bulging information and initial bulging information are set. The standard specimen's bulging information includes standard bulging dimensions, standard bulging height, bulging curve limit points, maximum allowable wrinkling height, and standard bulging specimen thickness. The initial bulging information includes axial feed pressure, axial feed speed, axial feed distance, bulging fluid pressure loading curve, and bulging fluid pressure. Using the bulging information of the standard specimen and the initial bulging information, the axial feed pressure and the bulging fluid pressure are applied to the initial specimen to obtain a pressurized bulging specimen; the height of the pressurized bulging specimen is obtained by measuring the pressurized bulging specimen through the mold using an infrared measuring instrument; based on the height of the pressurized bulging specimen and the bulging information of the standard specimen, a standard-shaped bulging specimen is obtained, wherein the mold is a composite mold of tempered glass and diamond, the interior of the composite mold is made of tempered glass, and the exterior of the tempered glass is coated with diamond; The mold is used to test the standard bulging specimen, and the bulging information of the standard specimen is used to control the forming quality of the hydraulically bulging specimen. An ultrasonic thickness gauge is used to inspect the standard-shaped bulging specimen through the mold to obtain the thickness of the standard-shaped bulging specimen; the thickness of the standard bulging specimen is compared with the thickness of the standard-shaped bulging specimen to obtain a standard bulging specimen, thereby achieving control over the forming quality of the hydraulic bulging specimen.

2. The method for quality control of hydraulic bulging specimen forming as described in claim 1, characterized in that, Based on the height of the bulging specimen under pressure and the bulging information of the standard specimen, the bulging specimen with the standard shape is obtained as follows: The height of the pressurized bulging specimen is compared with the standard bulging height; when the height of the pressurized bulging specimen is lower than the standard bulging height, the bulging fluid pressure and the axial feed distance are increased until the height of the pressurized bulging specimen reaches the limit point of the bulging curve, and the standard bulging specimen is obtained. When the height of the bulging specimen under pressure is higher than the standard bulging height, the axial feed speed and the axial feed distance are reduced until the height of the bulging specimen under pressure, the limiting point of the bulging curve, and the maximum allowable wrinkling height meet the bulging information of the standard specimen, and the standard shaped bulging specimen is obtained.

3. The method for quality control of hydraulic bulging specimen forming as described in claim 1, characterized in that, The standard bulging specimen thickness is obtained by comparing it with the thickness of the standard bulging specimen. If the thickness of the bulging specimen in the standard form does not meet the standard bulging specimen thickness, then the bulging specimen is a defective piece. If the thickness of the bulging specimen of the standard shape meets the thickness of the standard bulging specimen, then the bulging specimen is the standard bulging specimen.

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