A variable cross-section air intake duct calibration and inspection assembly mold and its application method

Abstract

A variable cross-section air intake duct calibration and inspection assembly mold and its usage method are disclosed. The theoretical model of the variable cross-section air intake duct consists of an upper small horn annular section and a lower large horn annular section streamlinedly connected as a whole. The usage method of the calibration and inspection assembly mold based on the theoretical model is as follows: A magnetic material assembly mold is made according to the theoretical model. When the assembly mold is used for calibration, the working surfaces of its front outer cover and rear outer cover assembly match the outer surface of the theoretical model. When the assembly mold is used for inspection, the working surfaces of its lower core mold and upper core mold assembly match the inner surface of the theoretical model. A magnetic fastening mechanism can be used to lock or loosen the assembly mold.

Description

Technical Field

[0001] This application relates to a sheet metal shaping and inspection mold in the field of aircraft manufacturing, specifically a common combination mold for shaping and inspecting a variable cross-section integral air intake and its usage method, which is particularly suitable for annular air intakes with a double-horn structure to perform cyclic quick loading and unloading of the mold to the required combination state by magnetization and demagnetization. Background Technology

[0002] It is well known that the forming and shaping of aerospace-grade hard aluminum alloys after solution heat treatment are subject to strict requirements regarding the room temperature duration. As the room temperature holding time increases after solution heat treatment, the material's deformation resistance increases, while its plasticity decreases. For example, for 2-series hard aluminum alloys, industry heat treatment standards such as XPS2001 stipulate that the allowable room temperature holding time after solution heat treatment is only 30 minutes. Forming and shaping beyond this specified incubation period not only increases the workload but also reduces product fatigue performance and may even lead to cracking. To overcome the limitations imposed by the incubation period on stable mass production, forming first, then solution heat treatment, and finally shaping is the most common method to balance plastic forming and achieving excellent service life. However, for thin-walled parts with complex mating surfaces, the deformation from solution heat treatment often prevents rapid positioning to the mold for shaping, limiting production to small batches or even single-piece production. Especially for complex parts with interference during unloading, repeated assembly of molds in various configurations is required for step-by-step shaping, making it easier to exceed the specified solution treatment time.

[0003] Currently, existing molds for sheet metal parts with interference during unloading mainly have two structures: segmented molds and combined molds. When using segmented molds, the parts requiring correction are sequentially corrected on their corresponding modules. The advantage is that the molds do not require assembly, resulting in high efficiency. However, the main drawbacks are as follows: the number of correction molds needs to be increased for different areas; because the parts are enclosed by the segmented molds, there are blind spots in the viewing angle, allowing only localized correction and not for checking the overall surface fit accuracy. The main advantage of using combined molds is that they can perform overall part correction and check the overall fit accuracy of the corrected parts. However, the main drawbacks are as follows: bolts are needed to complete various assembly states of the mold and parts; repeated disassembly and assembly can easily lead to wear on the connecting bolts and bolt holes, relative misalignment between parts, and reduced accuracy of the combined surface. Furthermore, repeated assembly and disassembly of combined molds is time-consuming and labor-intensive, making it difficult to meet the requirements for controlling the incubation period after solution heat treatment. Summary of the Invention

[0004] To overcome the shortcomings of using separate molds for overall alignment and inspection of dual-horn intake structures due to interference during component removal, and the drawbacks of combined molds requiring repeated loading and unloading, resulting in mold wear, time-consuming loading and unloading, and difficulty in meeting the requirements for rapid assembly and unloading in mass production, this application aims to provide a variable cross-section intake alignment and inspection combined mold and its usage method. Utilizing a switch-type magnetic fastening mechanism, the mold is instantly magnetized and demagnetized to quickly lock and unlock the required assembly state, achieving the requirement of completing any assembly state within seconds.

[0005] Technical solution

[0006] To achieve the aforementioned objectives, the technical solution adopted in this application is as follows:

[0007] A variable cross-section air intake duct calibration and inspection assembly mold, wherein the theoretical model of the variable cross-section air intake duct is formed by the streamlined connection of an upper small horn-shaped annular portion and a lower large horn-shaped annular portion, characterized in that: the assembly mold includes a lower core mold, an upper core mold, a front outer cover, and a rear outer cover. The lower core mold has a first base at its bottom, which forms an annular positioning platform around the lower core mold. Above the annular positioning platform is the annular working surface of the lower core mold, which matches the inner surface of the large horn-shaped annular portion of the variable cross-section air intake duct theoretical model. The upper core mold is superimposed on the top surface of the lower core mold. The upper core mold has a basin structure, and the outer side of the basin structure is the annular working surface of the upper core mold, which matches the inner surface of the small horn-shaped annular portion of the variable cross-section air intake duct theoretical model. The annular working surface of the upper core mold is continuously connected to the annular working surface of the lower core mold. The front and rear outer covers combine to form an outer mold that matches the upper and lower core molds. The bottom of the front outer cover has a second base that matches the front side of the first base annular positioning platform of the lower core mold, and the bottom of the rear outer cover has a third base that matches the rear side of the first base annular positioning platform of the lower core mold. The inner surfaces of the front and rear outer covers are working surfaces. The working surface of the front outer cover matches the outer surface of the front sidewall of the theoretical model, and the working surface of the rear outer cover matches the outer surface of the rear sidewall of the theoretical model. The top surface of the lower core mold and the bottom surface of the upper core mold have matching first positioning holes, and the first base of the lower core mold, the second base of the front outer cover, and the third base of the rear outer cover have matching second positioning holes.

[0008] Furthermore, the height of the upper and lower parting surfaces of the upper and lower core molds is lower than the height of the minimum cross-section of the theoretical model of the variable cross-section air intake.

[0009] Furthermore, the front and rear parting surfaces of the front and rear outer covers are located at the maximum length positions on the left and right sides of the variable cross-section intake duct theoretical model.

[0010] Furthermore, the lower core mold, upper core mold, front outer cover, and rear outer cover are made of magnetic material. A groove is provided on the top surface of the upper core mold, in which several independent magnetic fastening mechanisms can be placed. Each magnetic fastening mechanism is equipped with a knob switch. When the knob switch is on, the magnetic fastening mechanism automatically locks the combined mold through magnetic force transmission. When the knob switch is off, the magnetic force of the magnetic fastening mechanism disappears, and the combined mold automatically unlocks and relaxes.

[0011] Furthermore, the depth of the groove on the top surface of the upper core mold is greater than the height of the magnetic fastening mechanism, and any magnetic fastening mechanism can lift a rigid workpiece weighing no less than 50 kg when the bottom surface is in complete contact with a planar rigid workpiece with a roughness of not less than Ra6.4.

[0012] Furthermore, the lower core mold, upper core mold, front outer cover, and rear outer cover are rigid shell structures. The upper surfaces of the first base of the lower core mold, the second base of the front outer cover, and the third base of the rear outer cover are planes with a roughness of no more than Ra6.4. The upper surface of the first base of the lower core mold is in contact with the lower surfaces of the second base of the front outer cover and the third base of the rear outer cover, respectively, and the roughness of the contact surface is also no more than Ra6.4.

[0013] The method for using the above-mentioned combined mold to perform shape correction and inspection of variable cross-section air intakes is characterized by comprising the following steps:

[0014] 1) Place the semi-finished intake manifold that needs to be shaped on the lower core mold and press it to add the ear piece. After shaped the area of ​​the large horn ring below the top surface of the lower core mold, cut the ear piece.

[0015] 2) Press the shaped intake horn ring part onto the lower core mold ring working surface by using the front outer cover and the rear outer cover, and shape the small horn ring part on the inner surface of the assembly formed by the front outer cover and the rear outer cover.

[0016] 3) Remove the front and rear outer covers, place the upper core mold on the lower core mold, and use a soft patting board to pat the outer surface of the air intake along the combination of the upper and lower core molds to make it adhere to the mold, and perform overall shaping of the air intake.

[0017] 4) After checking the overall shape and ensuring the air intake duct fits into the lower and upper core molds, remove the upper core mold and separate the air intake duct from the lower core mold for demolding.

[0018] 5) First, place the front outer cover and the rear outer cover on the first base of the lower core mold, then place the upper core mold on the lower core mold to complete the mold assembly, and return the combined mold to the warehouse.

[0019] Furthermore, when the combined mold is used for the shaping of the large horn ring part of the air intake, the assembly and use method of the combined mold and the air intake is as follows: place the air intake on the lower core mold, place iron pads of the same thickness on both sides of the semi-finished supplementary ear piece, and press the semi-finished supplementary ear piece on the first base of the lower core mold through the magnetic fastening mechanism.

[0020] Furthermore, when the combined mold is used for the shaping of the small horn ring of the air intake, the assembly method of the combined mold and the air intake is as follows: the second base of the front outer cover and the third base of the rear outer cover press the shaped large horn ring of the air intake onto the working surface of the lower core mold through a magnetic fastening mechanism. In this assembled state, the working surface of the combination of the front outer cover and the rear outer cover is completely matched with the outer surface of the theoretical model of the air intake.

[0021] Furthermore, when the combined mold is used for overall shaping and inspection of the air intake, the assembly method of the combined mold and the air intake is as follows: the upper core mold is pressed onto the top surface of the lower core mold by the magnetic fastening mechanism of the top groove. In this assembled state, the working surface of the combination of the lower core mold and the upper core mold is completely matched with the inner surface of the theoretical model of the air intake.

[0022] Beneficial effects

[0023] This application's modular mold utilizes a switchable magnetic fastening mechanism to instantly lock and unlock the mold to the required assembly state by magnetizing and demagnetizing it. This significantly improves the efficiency of cyclic loading and unloading during batch production, avoids the wear and tear of traditional bolted connections, and also provides a shared function for overall alignment and inspection. The modular mold adopts a rigid thick-shell structure, making the mold components lightweight and easy to load and unload manually. Therefore, the modular mold used in this application has significant advantages such as lightweight structure, high loading and unloading efficiency, and low cost, which can improve loading and unloading efficiency by tens of times compared with traditional bolted connection methods.

[0024] The present application will be further described in detail below with reference to the accompanying drawings of the embodiments. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the shape of the theoretical model of the air intake in this application.

[0026] Figure 2 This is a schematic diagram of the shape of the semi-finished air intake duct of this application.

[0027] Figure 3 This is a schematic diagram of the upper core mold structure of the intake manifold assembly mold of this application.

[0028] Figure 4 This is a schematic diagram of the lower core mold structure of the intake manifold assembly mold of this application.

[0029] Figure 5 This is a schematic diagram illustrating the assembly and disassembly principle of the intake manifold assembly mold in this application.

[0030] Figure 6 This is a schematic diagram of the combined structure of the intake manifold assembly mold used for inspection in this application.

[0031] The numbers in the diagram are explained as follows: 1. Theoretical model, 2. Small horn ring, 3. Large horn ring, 4. Lower core mold, 5. Upper core mold, 6. Front outer cover, 7. Rear outer cover, 8. First base, 9. Second base, 10. Third base, 11. First positioning hole, 12. Second positioning hole, 13. Upper and lower parting surfaces, 14. Minimum cross section, 15. Front and rear parting surfaces, 16. Groove, 17. Magnetic fastening mechanism, 18. Knob switch, 19. Semi-finished product, 20. Additional ear piece. Detailed Implementation

[0032] First, we will introduce the variable cross-section air intake structure and the defects of its existing mold.

[0033] See attached document Figure 1 The theoretical model 1 of the variable cross-section intake duct consists of a streamlined connection between the upper small horn-shaped annular section 2 and the lower large horn-shaped annular section 3. After solution heat treatment, this intake duct requires rapid shaping during the material incubation period to improve assembly accuracy while minimizing deformation damage and meeting service requirements. Furthermore, because the theoretical model 1 is formed by the streamlined connection of irregular horn-shaped annular sections at both ends, and the mold is manufactured along the minimum cross-section 14, a localized part removal interference zone exists at the lower large horn-shaped annular section 3. To address the requirements of part removal interference and high surface fit accuracy, a combined mold needs to be manufactured to perform step-by-step shaping and inspection of the heat-treated deformed semi-finished product 19. Traditional combined molds require repeated loading and unloading of the mold and parts using bolts during the shaping and inspection process, which can lead to bolt wear or even stripping, resulting in misalignment of the mold components and damage to the parts' surfaces. In addition, the loading and unloading process of the combined mold is time-consuming and labor-intensive, making it difficult to meet the requirement of short-term residence time at room temperature after solution heat treatment, which seriously restricts the efficiency of batch production. Furthermore, the forced shaping due to material aging hardening can easily reduce the fatigue performance of the product, or even cause cracking and scrapping.

[0034] Next, the structure of the variable cross-section air intake duct calibration and inspection combination mold of this application will be introduced.

[0035] To overcome the aforementioned problems with existing combined molds due to low loading and unloading efficiency when used for intake duct heat treatment, shaping, and inspection, please refer to the appendix... Figure 1 To be continued Figure 6This application provides a combined mold capable of rapid assembly and disassembly within seconds, which simultaneously possesses calibration and inspection functions depending on the assembly state. The combined mold comprises a lower core mold 4, an upper core mold 5, a front outer cover 6, and a rear outer cover 7. The lower core mold 4 has a first base 8 at its bottom, forming an annular positioning platform around it. Above the annular positioning platform is the annular working surface of the lower core mold 4, which matches the inner surface of the large horn annular portion 3 of the variable cross-section intake duct theoretical model 1. The upper core mold 5 is superimposed on the top surface of the lower core mold 4. The upper core mold 5 has a basin structure, and its outer surface is the annular working surface, which matches the inner surface of the small horn annular portion 2 of the variable cross-section intake duct theoretical model 1. The annular working surface of the upper core mold 5 is continuously connected to the annular working surface of the lower core mold 4. The front outer cover 6 and rear outer cover 7 are combined to form an outer mold that matches the upper core mold 5 and the lower core mold 4. The bottom of the front outer cover 6 is provided with a second base 9 that matches the front side of the annular positioning platform of the first base 8 of the lower core mold 4, and the bottom of the rear outer cover 7 is provided with a third base 10 that matches the rear side of the annular positioning platform of the first base 8 of the lower core mold 4. The inner surfaces of the front outer cover 6 and the rear outer cover 7 are working surfaces. The working surface of the front outer cover 6 matches the outer surface of the front sidewall of the theoretical model 1, and the working surface of the rear outer cover 7 matches the outer surface of the rear sidewall of the theoretical model 1. The top surface of the lower core mold 4 and the bottom surface of the upper core mold 5 are provided with matching first positioning holes 11, and the first base 8 of the lower core mold 4, the second base 9 of the front outer cover 6, and the third base 10 of the rear outer cover 7 are provided with matching second positioning holes 12. The basic structure of the mold needs to be explained as follows: First, the lower core mold 4 is provided with a first base 8, the front outer cover 6 is provided with a second base 9, and the rear outer cover 7 is provided with a third base 10 for clamping and assembly. Secondly, a first positioning hole 11 is provided between the lower core mold 4 and the upper core mold 5, and a second positioning hole 12 is provided between the lower core mold 4 and the front outer cover 6 and the rear outer cover 7. The purpose of this is to prevent the mold components from being misaligned and to avoid surface damage during the forming process. Thirdly, the ultimate goal of the above design is to enable the combined mold to have both segmented forming and overall forming functions, and it can also be used for overall inspection of the air intake fitting accuracy.

[0036] Furthermore, in order to solve the problem of interference during component removal at the minimum cross-section 14 due to the variable cross-section of the intake duct, the upper and lower parting surfaces 13 of the upper core mold 5 and the lower core mold 4 are positioned at a height lower than the minimum cross-section 14 of the variable cross-section intake duct theoretical model 1; the front and rear parting surfaces 15 of the front outer cover 6 and the rear outer cover 7 are located at the maximum length positions on the left and right sides of the variable cross-section intake duct theoretical model 1.

[0037] Furthermore, to enable rapid switching between various assembly methods of the mold and parts during the use of the combined mold, the lower core mold 4, upper core mold 5, front outer cover 6, and rear outer cover 7 are made of magnetic material. A groove 16 is provided on the top surface of the upper core mold 4, within which several independent magnetic fastening mechanisms 17 can be placed. Each magnetic fastening mechanism 17 is equipped with a rotary switch 18. When the rotary switch 18 is open, the magnetic fastening mechanism 17 automatically locks the combined mold through magnetic force transmission; when the rotary switch 18 is closed, the magnetic force of the magnetic fastening mechanism 17 disappears, and the combined mold automatically unlocks and relaxes.

[0038] Furthermore, to prevent the magnetic fastening mechanism from being lost or attracted to other workpieces during transportation and use, the depth of the groove 16 on the top surface of the upper core mold 5 is preferably greater than the height of the magnetic fastening mechanism 17. When any magnetic fastening mechanism 17 is in complete contact with a planar rigid workpiece with a roughness of not less than Ra6.4, it can lift a rigid workpiece with a weight of not less than 50 kg. Limiting the magnetic force is another purpose to prevent the mold from loosening due to hammering during the shaping process, and to prevent the edge of the mold parting surface from damaging the surface of the air intake.

[0039] Furthermore, to minimize the weight of the mold components and facilitate manual handling, the lower core mold 4, upper core mold 5, front outer cover 6, and rear outer cover 7 of the combined mold are rigid shell structures. Additionally, to ensure effective magnetic assembly and locking, the upper surfaces of the first base 8 of the lower core mold 4, the second base 9 of the front outer cover 6, and the third base 10 of the rear outer cover 7 are flat surfaces with a roughness not exceeding Ra6.4. The upper surface of the first base 8 of the lower core mold 4 contacts the lower surfaces of the second base 9 of the front outer cover 6 and the third base 10 of the rear outer cover 7, with a surface roughness also not exceeding Ra6.4. This is because the smoother the contact surface, the smaller the contact gap, and the better the magnetic attraction and locking effect. It should be noted that the milling roughness of the non-working surface of the mold is generally better than Ra3.2; therefore, a surface roughness of Ra6.4 for the magnetic fastening parts of the mold is sufficient for use. To ensure the magnetic clamping effect, the surface roughness of the magnetic attraction parts of the combined mold only needs to be better than the surface roughness of the rigid workpiece used for testing the magnetic force.

[0040] This paper will again introduce the usage method of the variable cross-section air intake duct assembly mold of this application.

[0041] For the method of using the above-mentioned combined mold for the shaping and inspection of variable cross-section air intakes, please refer to the appendix. Figure 1 To be continued Figure 6 Its characteristics include the following:

[0042] 1) Place the semi-finished air intake duct 19, which requires shaping after solution heat treatment, on the lower core mold 4 and press down its supplementary ear piece 20. After shaping the area of ​​the large horn ring part 3 below the top surface of the lower core mold 4, cut the supplementary ear piece 20. It should be noted that: in order to avoid blind spots in the viewing angle due to the air intake duct surface covering the working surface of the lower core mold 4, the shaping area of ​​about 5mm from the top surface of the lower core mold 4 can be marked according to the mold markings before shaping and hammering.

[0043] 2) The shaped intake duct large horn annular part 3 is pressed onto the annular working surface of the lower core mold 4 by the front outer cover 6 and the rear outer cover 7. The small horn annular part 2 is shaped on the inner surface of the assembly formed by the front outer cover 6 and the rear outer cover 7. It should be noted that in order to avoid mismatch of the shape of the shaped large horn annular part 3, which would affect the pressing effect of the front outer cover 6 and the rear outer cover 7, the second positioning hole 12 on the front outer cover 6 and the rear outer cover 7 can be designed as a horn-shaped structure with an open bottom. At the same time, the number of magnetic fastening mechanisms 17 on the base can also be increased.

[0044] 3) Remove the front outer cover 6 and the rear outer cover 7, place the upper core mold 5 on the top surface of the lower core mold 4, and use a soft patting plate to pat the outer surface of the air intake along the combination of the upper core mold 5 and the lower core mold 4 to make it adhere to the mold, and perform overall shaping of the air intake.

[0045] 4) After checking the overall shape and ensuring the air intake duct fits into the lower core mold 4 and upper core mold 5 assembly, remove the upper core mold 5 and separate the air intake duct from the lower core mold 4 for demolding.

[0046] 6) First, place the front outer cover 6 and the rear outer cover 7 onto the first base 8 of the lower core mold 4, then place the upper core mold 5 onto the lower core mold 4 to complete the mold assembly, and return the assembled mold to the warehouse.

[0047] Finally, the following points need to be added regarding the assembly status and usage techniques of the modular mold:

[0048] First, when the combined mold is used for shaping the large horn annular part 3 of the air intake, the assembly method of the combined mold and the air intake is as follows: the air intake is placed on the lower core mold 4, and iron pads of the same thickness are placed on both sides of the supplementary ear piece 20 on the semi-finished product 19. The supplementary ear piece 20 is pressed onto the first base 8 of the lower core mold 4 by the magnetic fastening mechanism 17. The purpose of placing iron pads on both sides of the supplementary ear piece 20 is to increase the magnetic pressing effect. Second, when the combined mold is used for shaping the small horn annular part 2 of the air intake, the assembly method of the combined mold and the air intake is as follows: the second base 9 of the front outer cover 6 and the third base 10 of the rear outer cover 7 press the shaped large horn annular part 3 of the air intake onto the annular working surface of the lower core mold 4 by the magnetic fastening mechanism 17. In this assembled state, the working surface of the combination of the front outer cover 6 and the rear outer cover 7 is completely matched with the outer surface of the theoretical model 1 of the air intake. In order to improve the pressing effect, the number of magnetic fastening mechanisms 17 on the base can be increased. Third, when the combined mold is used for overall shaping and inspection of the air intake, the assembly and use of the combined mold and the air intake is as follows: the upper core mold 5 is pressed onto the top surface of the lower core mold 4 by the magnetic fastening mechanism 17 in the top groove 16. In this assembled state, the working surface of the combination of core mold 4 and upper core mold 5 is completely matched with the inner surface of the theoretical model 1 of the air intake.

[0049] After use, the combined mold is in a fully closed state. All magnetic fastening mechanisms 17 are collected in the groove 16 on the top surface of the upper core mold 5. Opening the rotary switch 18 of the magnetic fastening mechanism 17 within the groove allows for instantaneous automatic locking of the combined mold via magnetic force. Closing all the rotary switches 18 of the magnetic fastening mechanisms within the groove 16 demagnetizes the combined mold, instantly eliminating the locking force between mold components. This allows the combined mold to quickly return to any of the three assembly states mentioned above. Compared to traditional bolted connection methods, this method improves loading and unloading efficiency by tens of times; it is particularly suitable for products with interference during unloading and requires rapid, repeated loading and unloading of combined molds in multiple assembly states for mass production.

Claims

1. A method for using a variable cross-section intake duct calibration and inspection assembly mold, wherein the theoretical model of the variable cross-section intake duct consists of an upper small horn-shaped annular portion and a lower large horn-shaped annular portion streamlinedly connected as a whole. Because the theoretical model of the intake duct consists of two irregularly shaped horn-shaped annular portions streamlinedly connected as a whole, the assembly mold is manufactured along the minimum cross-section boundary. A local unloading interference zone exists at the lower large horn-shaped annular portion. The variable cross-section intake duct calibration and inspection assembly mold is used. The assembly mold includes a lower core mold, an upper core mold, a front outer cover, and a rear outer cover. The bottom of the lower core mold is provided with a first base. A base surrounds the lower core mold to form an annular positioning platform. Above the annular positioning platform is the annular working surface of the lower core mold, which matches the inner surface of the large horn-shaped annular portion of the variable cross-section intake duct theoretical model. The upper core mold is superimposed on the top surface of the lower core mold. The height of the upper and lower parting surfaces of the upper and lower core molds is lower than the height of the minimum cross-section position of the variable cross-section intake duct theoretical model. The upper core mold has a basin structure, and the outer surface of the basin structure is the annular working surface of the upper core mold. This annular working surface matches the inner surface of the small horn-shaped annular portion of the variable cross-section intake duct theoretical model. The working surface is continuously connected to the annular working surface of the lower core mold; the front outer cover and the rear outer cover are combined to form an outer mold that matches the upper core mold and the lower core mold. The bottom of the front outer cover is provided with a second base that matches the front side of the first base annular positioning platform of the lower core mold, and the bottom of the rear outer cover is provided with a third base that matches the rear side of the first base annular positioning platform of the lower core mold. The inner surfaces of the front outer cover and the rear outer cover are working surfaces. The working surface of the front outer cover matches the outer surface of the front sidewall of the theoretical model, and the working surface of the rear outer cover matches the outer surface of the rear sidewall of the theoretical model; the top surface of the lower core mold and the bottom surface of the upper core mold are provided with... The lower core mold has a first positioning hole that matches each other, and the first base of the lower core mold, the second base of the front outer cover, and the third base of the rear outer cover have second positioning holes that match each other. The lower core mold, the upper core mold, the front outer cover, and the rear outer cover are made of magnetic material. The top surface of the upper core mold has a groove in which several independent magnetic fastening mechanisms can be placed. Each magnetic fastening mechanism has a knob switch. When the knob switch is on, the magnetic fastening mechanism automatically locks the combined mold through magnetic force transmission. When the knob switch is off, the magnetic force of the magnetic fastening mechanism disappears, and the combined mold automatically unlocks and relaxes. Its features Includes the following: 1) Place the semi-finished intake manifold requiring correction on the lower core mold and press its supplementary lugs. After correcting the area of ​​the large horn ring below the top surface of the lower core mold, cut the supplementary lugs. When the combined mold is used for correcting the large horn ring of the intake manifold, the assembly method of the combined mold and the intake manifold is as follows: place the intake manifold on the lower core mold, place iron pads of the same thickness on both sides of the semi-finished supplementary lugs, and press the semi-finished supplementary lugs onto the first base of the lower core mold through a magnetic fastening mechanism; 2) Press the corrected large horn ring of the intake manifold onto the lower core mold through the front outer cover and the rear outer cover. 3) Shape the small horn ring on the inner surface of the assembly formed by the front outer cover and the rear outer cover; 4) Remove the front outer cover and the rear outer cover, place the upper core mold on the lower core mold, and use a soft patting board to pat the outer surface of the air intake along the assembly formed by the upper core mold and the lower core mold to make it adhere to the mold, and shape the air intake as a whole; 5) After checking that the air intake adheres to the assembly of the lower core mold and the upper core mold after overall shaping, remove the upper core mold and separate the air intake from the lower core mold to demold; 6) First place the front outer cover and the rear outer cover on the lower core mold, and then place the upper core mold on the lower core mold to complete the mold assembly, and return the combined mold to the warehouse.

2. The method of using the variable cross-section intake duct calibration and inspection combination mold as described in claim 1, characterized in that, The front and rear outer cover and the rear outer cover are located at the maximum length position on the left and right sides of the variable cross-section intake duct theoretical model.

3. The method of using the variable cross-section intake manifold calibration and inspection combination mold as described in claim 1, characterized in that: The depth of the groove on the top surface of the upper core mold is greater than the height of the magnetic fastening mechanism. When any magnetic fastening mechanism is in complete contact with a planar rigid workpiece with a roughness of not less than Ra6.4, it can lift a rigid workpiece with a weight of not less than 50 kg.

4. The method of using the variable cross-section intake manifold calibration and inspection combination mold as described in claim 1, characterized in that: The lower core mold, upper core mold, front outer cover, and rear outer cover are rigid shell structures. The upper surfaces of the first base of the lower core mold, the second base of the front outer cover, and the third base of the rear outer cover are planes with a roughness of no more than Ra6.

4. The upper surface of the first base of the lower core mold is in contact with the lower surfaces of the second base of the front outer cover and the third base of the rear outer cover, respectively, and the roughness of the contact surface is also no more than Ra6.

4.

5. The method of using the variable cross-section intake manifold calibration and inspection combination mold as described in claim 1, characterized in that: When the combined mold is used for the shaping of the small horn ring part of the air intake, the assembly method of the combined mold and the air intake is as follows: the second base of the front outer cover and the third base of the rear outer cover press the shaped large horn ring part of the air intake onto the working surface of the lower core mold through a magnetic fastening mechanism. In this assembled state, the working surface of the combination of the front outer cover and the rear outer cover is completely matched with the outer surface of the theoretical model of the air intake.

6. The method of using the variable cross-section intake manifold calibration and inspection combination mold as described in claim 1, characterized in that: When the combined mold is used for overall shaping and inspection of the air intake, the assembly method of the combined mold and the air intake is as follows: the upper core mold is pressed onto the top surface of the lower core mold by a magnetic fastening mechanism in the groove on the top surface. In this assembled state, the working surface of the combination of the lower core mold and the upper core mold is completely matched with the inner surface of the theoretical model of the air intake.

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