A double-layer pneumatic blank holder device for viscous medium forming of a ring-shaped thin-walled part and a working method

Abstract

The application discloses a double-layer inflatable edge ring device for viscous medium forming of a ring-shaped thin-wall part and a working method thereof, and relates to the technical field of edge ring devices. The edge ring device comprises a viscous medium forming assembly and an edge ring pressure control assembly, and the edge ring pressure control assembly is used for providing an edge pressure for the viscous medium forming assembly. The edge ring of the edge ring device adopts a double-layer inflatable structure, and can be closely combined with a forming plate with different structural characteristics. The edge pressure during the forming process of the plate can be controlled by adjusting the air pressure, the edge pressure of the plate is uniformly distributed in the circumferential direction, the generation of wrinkles at the edge of the formed part is reduced, and the forming quality of the ring-shaped thin-wall part is improved.

Description

Technical Field

[0001] This invention relates to the field of sheet metal forming technology for aero-engines, specifically to a double-layer pneumatic pressure ring device for forming annular thin-walled parts using viscous media. Background Technology

[0002] Annular thin-walled structures are widely used in the structural design of key components for aero-engines. These parts are often complex, irregularly shaped, and frequently utilize difficult-to-machine materials such as high-temperature alloys and titanium alloys. The forming process presents challenges including high machining difficulty, difficulty in controlling forming accuracy, and irregular springback, often resulting in defects such as edge wrinkles and cracks. The blank holder, as a crucial device in the viscous medium forming process of sheet metal, significantly impacts the forming quality of the parts. Traditional blank holders are fixed structures, making it difficult to achieve consistent stress distribution in complex structural parts, thus limiting the forming performance of the material and the dimensional accuracy of the formed parts. This invention proposes a double-layer pneumatic blank holder device for viscous medium forming of annular thin-walled parts. The blank holder employs a double-layer inflatable structure, ensuring a tight fit with the sheet metal for various structural characteristics. By adjusting the air pressure, the blank holder force during the forming process is controlled, resulting in a uniform circumferential distribution of the blank holder force, thereby reducing wrinkles at the blank holder and improving the forming quality of the annular thin-walled parts. Summary of the Invention

[0003] To address the problems existing in the prior art, this invention provides a double-layer pneumatic blanking ring device for forming annular thin-walled parts using viscous media. This device overcomes the stress concentration problems encountered in the complex curved surface contact area between the viscous medium and the combustion chamber cap during the forming of large-sized aero-engine components using viscous media. The method introduces a double-layer inflatable blanking ring into the forming process of circumferential thin-walled parts using viscous media, reducing the generation of cracks and wrinkles in the blanking area, thereby improving the forming quality of the parts.

[0004] This invention is achieved through the following technical solution: A double-layer pneumatic blank holder device for forming annular thin-walled parts with viscous media includes a viscous media forming assembly and a blank holder pressure control assembly. The pressure control component of the pressure ring is used to provide pressure force to the viscous medium forming component; under the action of the pressure control component, the viscous medium forming component achieves uniform circumferential distribution of pressure force in each area during the forming process of the sheet metal blank by the viscous medium forming component. The viscous medium forming assembly includes a die, a viscous medium chamber, a viscous medium injection cylinder, a viscous medium pressure loading cylinder, and a frame; The die is positioned above the viscous medium chamber, and a plate blank is positioned between the die and the viscous medium chamber. The viscous medium injection cylinder is positioned below the viscous medium chamber, and the medium chamber inside the viscous medium injection cylinder communicates with the internal cavity of the viscous medium chamber. The viscous medium pressure loading cylinder is positioned below the viscous medium injection cylinder, and the fixed end of the viscous medium pressure loading cylinder is installed at the bottom of the frame. The pressure control assembly for the pressure ring includes an upper pressure ring and a lower pressure ring. The upper pressure ring is disposed in the hemispherical groove of the die cavity, and the lower pressure ring is disposed in the hemispherical groove of the viscous medium chamber.

[0005] Preferably, the viscous medium forming assembly further includes a viscous medium forming control system, under the control of the viscous medium forming control system, the viscous medium pressure loading cylinder provides and controls the loading pressure of the viscous medium placed in the viscous medium chamber.

[0006] Preferably, the pressure control assembly for the edge clamping ring further includes a pressure control system, which includes a three-way air valve and a pressure control gauge. The pressure control system is used to provide edge clamping force to the viscous medium forming process of the sheet blank. Both the upper edge clamping ring and the lower edge clamping ring are connected to the three-way air valve, and the pressure control gauge is used to regulate the edge clamping force.

[0007] Preferably, during the forming process of the sheet blank, both the upper and lower pressure rings are in an inflated state with an air pressure of MPa, and the pressure control system provides the pressure force for the period from the start of forming the sheet blank to the end of forming.

[0008] Preferably, it further includes a plunger, one end of which extends into the viscous medium pressure loading cylinder and is connected to the piston inside the viscous medium pressure loading cylinder, and the other end of which extends into the viscous medium injection cylinder and is connected to the piston inside the viscous medium injection cylinder.

[0009] Preferably, both the upper and lower pressure rings are made of silicone rubber. Preferably, the lower pressure edge ring is disposed on the viscous medium chamber, and the lower pressure edge ring also functions as a sealing ring during the forming process of the sheet blank in the viscous medium.

[0010] Preferably, the viscous medium is methyl vinyl silicone rubber with a molecular weight of 600 kg / mol; the loading pressure of the viscous medium is 600 MPa; and the diameter of the sheet blank is 850 mm and the thickness is 1.0 mm.

[0011] A method for operating a double-layer pneumatic pressure ring device for forming annular thin-walled parts with viscous media includes: S1. In the initial state, the sheet material is clamped between the die and the viscous medium chamber. The upper pressure ring is embedded in the hemispherical groove of the die, and the lower pressure ring is embedded in the hemispherical groove of the viscous medium chamber. Both are in an uninflated state. S2. Gas is simultaneously injected into the upper and lower pressure rings through the pressure control system, causing them to expand and apply a uniform circumferential pressure force to the upper and lower surfaces of the sheet blank, and the pressure force is maintained until the forming process is completed. S3. Control the action of the viscous medium pressure loading cylinder. Drive the piston in the viscous medium injection cylinder through the plunger to inject the viscous medium into the viscous medium chamber and raise its pressure to the target loading pressure, thereby pushing the plate blank to undergo plastic deformation and adhere to the concave mold cavity. S4. Under the combined action of constant viscous medium loading pressure and constant double-layer pneumatic edge-pressing force, maintain for a period of time to complete the final forming of the plate blank; S5. After molding is completed, the loading pressure of the viscous medium is removed. Then, the gas in the upper and lower pressure rings is released through the pressure control system to relieve the pressure force. Finally, the mold is opened and the molded part is taken out.

[0012] Compared with the prior art, the present invention has the following beneficial technical effects: The present invention discloses a double-layer pneumatic edge-pressing ring device for forming annular thin-walled parts using viscous media. The edge-pressing ring adopts a double-layer inflatable structure. For forming plates with different structural characteristics, the edge-pressing ring can achieve a tight fit with the plate. By adjusting the air pressure, the edge-pressing force during the forming process of the plate is controlled, so that the edge-pressing force in each area of ​​the plate is evenly distributed circumferentially, thereby reducing the generation of wrinkles at the edge of the formed part and achieving the purpose of improving the forming quality of annular thin-walled parts. Attached Figure Description

[0013] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0014] The structures, proportions, sizes, etc. illustrated in this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed herein, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0015] Figure 1This is a schematic diagram of the initial state structure of a double-layer pneumatic pressure ring device for forming annular thin-walled parts with viscous medium, provided for some embodiments of the present invention.

[0016] Figure 2 This is a schematic diagram of the edge-pressing state structure of a double-layer pneumatic edge-pressing ring device for forming annular thin-walled parts with viscous media, provided for some embodiments of the present invention.

[0017] Figure 3 This is a schematic diagram of the forming state structure of a double-layer pneumatic pressure ring device for forming annular thin-walled parts with viscous media, provided for some embodiments of the present invention.

[0018] Figure 4 This is a schematic diagram of the structure of a double-layer pneumatic pressure ring device for forming annular thin-walled parts using viscous media, provided for some embodiments of the present invention.

[0019] Figure 5 This is a schematic diagram of the forming dimensions of a double-layer pneumatic pressure ring device for forming annular thin-walled parts using viscous media, provided for some embodiments of the present invention.

[0020] In the diagram: 1. Die, 2. Sheet metal blank, 31. Upper pressure ring, 32. Lower pressure ring, 4. Viscous medium, 5. Viscous medium chamber, 6. Viscous medium injection cylinder, 7. Plunger, 8. Viscous medium pressure loading cylinder, 9. Frame, 10. Pressure control system, 101. Three-way air valve, 102. Air pressure control gauge, 11. Viscous medium forming pressure control system. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0022] This invention provides a double-layer pneumatic blank holder device for forming annular thin-walled parts with viscous medium, including a viscous medium forming component and a blank holder pressure control component. Under the action of the blank holder pressure control component, the viscous medium forming component ensures that the blank holder force in each region is evenly distributed circumferentially during the forming process of the sheet metal blank 2 by the viscous medium forming component.

[0023] like Figure 1 and Figure 2 As shown, the viscous medium forming assembly includes a die 1, a viscous medium chamber 5, a viscous medium injection cylinder 6, a viscous medium pressure loading cylinder 8, and a frame 9.

[0024] Among them, frame 9 serves as the supporting foundation for the entire device.

[0025] The viscous medium pressure loading cylinder 8 has its cylinder body fixedly installed at the bottom of the frame 9, serving as the final pressure source.

[0026] The viscous medium injection cylinder 6 is positioned above the viscous medium pressure loading cylinder 8, and a piston is installed inside it.

[0027] A plunger 7 has one end inserted into the viscous medium pressure loading cylinder 8 and connected to the piston therein, and the other end inserted into the viscous medium injection cylinder 6 and connected to the piston therein. Thus, the piston movement of the viscous medium pressure loading cylinder 8 can drive the piston movement of the viscous medium injection cylinder 6 synchronously.

[0028] The viscous medium chamber 5 is fixedly installed above the viscous medium injection cylinder 6, and its internal cavity is connected to the medium chamber of the viscous medium injection cylinder 6 to contain the viscous medium 4.

[0029] A die 1 is positioned above the viscous medium reservoir 5. An annular sheet blank 2 to be formed is placed between the die 1 and the viscous medium reservoir 5. In this embodiment, the sheet blank 2 has a diameter of 850 mm and a thickness of 1.0 mm.

[0030] The viscous medium forming control system 11 is electrically connected to the viscous medium pressure loading cylinder 8, and is used to precisely control its output load, thereby indirectly controlling the loading pressure of the viscous medium 4 acting on the lower surface of the sheet blank 2. In this embodiment, the loading pressure is set to 600 MPa. The viscous medium 4 is preferably methyl vinyl silicone rubber with a molecular weight of 600 kg / mol.

[0031] The pressure control assembly for the blank holder ring is used to provide a blank holder force to the viscous medium forming assembly, including: The upper pressure ring 31 is annular and is embedded in the hemispherical groove of the die 1, located above the sheet metal blank 2.

[0032] The lower pressure ring 32, also annular in shape, is embedded in the hemispherical groove of the viscous medium chamber 5, located below the sheet blank 2. During the forming process, the lower pressure ring 32 applies pressure force while also acting as a sealing ring to prevent the viscous medium 4 from leaking from the contact interface between the viscous medium chamber 5 and the sheet blank 2.

[0033] The pressure control system 10 includes a three-way valve 101 and a pressure control gauge 102. Both the upper pressure ring 31 and the lower pressure ring 32 are hollow bladder-like structures and are connected to the three-way valve 101 via air passages, thereby enabling simultaneous inflation and pressure control of the upper and lower pressure rings. The pressure control gauge 102 is used to precisely regulate the gas pressure injected into the pressure rings.

[0034] In this embodiment, both the upper pressure ring 31 and the lower pressure ring 32 are made of silicone rubber. This material possesses excellent high and low temperature stability, maintaining good elasticity within the temperature range of -70℃ to 200℃ involved in the forming process of the sheet blank 2, ensuring effective operation even under harsh conditions. During the forming process, both the upper pressure ring 31 and the lower pressure ring 32 are in an inflated state, with their internal air pressure controlled at 400MPa by the pressure control system 10, and this pressure force is maintained throughout the entire forming process from the start to the end of the forming of the sheet blank 2.

[0035] The working principle of this invention is as follows: By using double-layered inflatable blank holder rings positioned on the upper and lower sides of the sheet metal blank 2, a uniform and flexible circumferential blank holder force is applied to the flange edge area of ​​the blank during the forming process. This design allows the blank holder force to perfectly conform to the curved surface of the blank, effectively alleviating the problem of localized stress concentration caused by traditional rigid blank holders. This significantly suppresses the tendency of the sheet metal to develop cracks and wrinkles in the blank holder area, ultimately achieving the goal of improving the forming quality of large annular thin-walled parts.

[0036] Traditional rigid blank holders are difficult to adapt to complex curved surfaces, easily leading to uneven pressure distribution. This invention employs a double-layered, inflatable blank holder structure. By filling it with controllable air pressure, the flexible silicone rubber blank holder can closely conform to the curved contour of the sheet material, thereby applying a uniform and stable circumferential blank holder force throughout the entire flange area of ​​the sheet material. This flexible pressure application method using surface contact effectively eliminates the localized stress concentration phenomena caused by traditional line or point contact.

[0037] This device can precisely control the material flow of sheet metal during the forming process. On the one hand, the uniform constraint force effectively prevents wrinkling in the flange area of ​​the sheet metal caused by uneven pressure or obstructed material flow. On the other hand, it avoids the risk of excessive thinning or even cracking of the sheet metal due to excessive local stress. The end result is a significant improvement in the forming accuracy and surface quality of annular thin-walled parts (such as the combustion chamber cap of an aero-engine), and a substantial increase in yield.

[0038] The device can flexibly adapt to different structural features and materials of molded sheets by simply adjusting the air pressure, making process adjustments quick and easy. Secondly, the selected silicone rubber pressure ring material possesses excellent high and low temperature stability (-70℃~200℃), ensuring that it maintains elasticity and performance even under harsh molding process conditions, guaranteeing the stability and repeatability of the molding process. Furthermore, the lower pressure ring also serves a sealing function, simplifying the structure and improving the reliability of the device.

[0039] Example 2: Method of using a double-layer pneumatic pressure ring device for forming annular thin-walled parts with viscous medium. This embodiment provides a method for forming an annular thin-walled part using the apparatus described in Embodiment 1, specifically including the following steps: S1: Equipment preparation and billet clamping like Figure 1 As shown, first, ensure that all components of the device are in their initial state. Place the annular plate blank 2 with a diameter of 850mm and a thickness of 1.0mm on the upper surface positioning area of ​​the viscous medium chamber 5. Then, the drive device closes, causing the die 1 to descend and close with the viscous medium chamber 5, pressing the flange area of ​​the plate blank 2 between them.

[0040] S2: Activate double-layer aerodynamic pressure force like Figure 2 As shown, after mold closing, the pressure control system 10 is activated. The three-way air valve 101 is opened, simultaneously filling the internal cavities of the upper pressure ring 31 and the lower pressure ring 32 with gas through the air passage. The air pressure control gauge 102 monitors and precisely regulates the pressure in the upper and lower pressure rings to reach and stabilize at the preset 400 MPa. This pressure force state will continue from the start of forming to the end of forming, providing uniform flexible constraint to the flange area of ​​the sheet metal throughout the process.

[0041] S3: Inject viscous medium and apply forming pressure. like Figure 3 As shown, after the blank holder force is established, the viscous medium forming control system 11 is activated. This system controls the viscous medium pressure loading cylinder 8 to move, pushing the piston in the viscous medium injection cylinder 6 upwards via the plunger 7, injecting and filling the viscous medium chamber 5 with the pre-stored viscous medium 4 (methyl vinyl silicone rubber with a molecular weight of 600 kg / mol). The control system continues to instruct the viscous medium pressure loading cylinder 8 to increase the pressure, steadily raising the pressure of the viscous medium 4 to the target value of 600 MPa. Under this high pressure, the viscous medium 4 acts as a flexible punch, uniformly pushing the central region of the sheet blank 2 towards the cavity of the die 1.

[0042] S4: Pressure holding molding like Figure 4As shown, under the combined action of a constant 600MPa viscous medium pressure and a constant 400MPa double-layer blank holder force, the pressure is maintained for a period of time. During this period, the sheet blank 2 undergoes sufficient plastic deformation, and its central area gradually adheres to the hemispherical surface of the die 1, ultimately forming the desired complex curved surface shape. The double-layer inflatable blank holder effectively controls the flow of the sheet material, preventing local thinning and cracking caused by excessive drawing, and also suppressing wrinkling caused by material accumulation.

[0043] S5: Depressurization, Venting, and Part Removal like Figure 5 As shown, after the pressure holding period, the forming process is complete. The viscous medium forming control system 11 controls the viscous medium pressure loading cylinder 8 to release pressure, and the viscous medium 4 flows back into the viscous medium injection cylinder 6 under the action of pressure difference. Subsequently, the gas in the upper pressure ring 31 and the lower pressure ring 32 is released through the three-way air valve 101 of the pressure control system 10, thus relieving the pressure force. Finally, the mold is opened, allowing the die 1 to move upward, and the formed qualified annular thin-walled part can be taken out from the viscous medium chamber 5.

[0044] This method utilizes a double-layer pneumatic pressure ring to achieve precise control over the forming process of large annular thin-walled parts in viscous media, significantly improving the forming accuracy and quality consistency of the parts.

[0045] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0046] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0047] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixation," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances. When a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be an intervening component. When a component is considered to be "set on" another component, it can be directly set on the other component or there may be an intervening component.

[0048] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0049] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0051] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Those skilled in the art can readily implement the present invention based on the accompanying drawings and the above description. However, any modifications, alterations, or variations made by those skilled in the art without departing from the scope of the present invention, utilizing the disclosed technical content, are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, or variations made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the present invention.

Claims

1. A double-layer pneumatic pressure ring device for forming annular thin-walled parts with viscous media, characterized in that, Includes a viscous medium forming assembly and a pressure control assembly for the pressure ring. The pressure control component of the pressure ring is used to provide pressure force to the viscous medium forming component; under the action of the pressure control component of the pressure ring, the viscous medium forming component realizes that the pressure force in each area is evenly distributed in the circumferential direction during the forming process of the viscous medium forming component processing the plate blank (2); The viscous medium forming assembly includes a die (1), a viscous medium chamber (5), a viscous medium injection cylinder (6), a viscous medium pressure loading cylinder (8), and a frame (9). The die (1) is positioned above the viscous medium chamber (5), and a plate blank (2) is positioned between the die (1) and the viscous medium chamber (5). The viscous medium injection cylinder (6) is positioned below the viscous medium chamber (5), and the medium chamber inside the viscous medium injection cylinder (6) is connected to the internal cavity of the viscous medium chamber (5). The viscous medium pressure loading cylinder (8) is positioned below the viscous medium injection cylinder (6), and the fixed end of the viscous medium pressure loading cylinder (8) is installed at the bottom of the frame (9). The pressure control assembly for the blank holder includes an upper blank holder (31) and a lower blank holder (32). The upper blank holder (31) is disposed in the hemispherical groove of the die (1), and the lower blank holder (32) is disposed in the hemispherical groove of the viscous medium chamber (5). The materials of the upper blank holder (31) and the lower blank holder (32) are both silicone rubber. The upper blank holder (31) and the lower blank holder (32) are both hollow capsule structures. During the forming process, the upper blank holder (31) and the lower blank holder (32) are inflated to apply circumferential blank holder force to the flange edge area of ​​the sheet blank (2). The pressure control assembly for the blank holder also includes a pressure control system (10).

2. The double-layer pneumatic pressure ring device for forming annular thin-walled parts with viscous media according to claim 1, characterized in that, The viscous medium forming assembly also includes a viscous medium forming control system (11), under the control of the viscous medium forming control system (11), the viscous medium pressure loading cylinder (8) provides and controls the loading pressure of the viscous medium (4) placed in the viscous medium chamber (5).

3. The double-layer pneumatic pressure ring device for forming annular thin-walled parts with viscous media according to claim 1, characterized in that, The pressure control system (10) includes a three-way air valve (101) and a pressure control gauge (102). The pressure control system (10) is used to provide a pressing force to the viscous medium forming process of the sheet blank (2). The upper pressing ring (31) and the lower pressing ring (32) are both connected to the three-way air valve (101). The pressure control gauge (102) is used to regulate the pressing force.

4. The double-layer pneumatic pressure ring device for forming annular thin-walled parts with viscous media according to claim 1, characterized in that, During the forming process, the upper pressure ring (31) and the lower pressure ring (32) of the plate blank (2) are both in an inflated state with an air pressure of 400MPa. The pressure control system (10) provides the pressure force for the period from the start of forming of the plate blank (2) to the end of forming.

5. The double-layer pneumatic pressure ring device for forming annular thin-walled parts with viscous media according to claim 1, characterized in that, It also includes a plunger (7), one end of which extends into the viscous medium pressure loading cylinder (8) and is connected to the piston inside the viscous medium pressure loading cylinder (8), and the other end of which extends into the viscous medium injection cylinder (6) and is connected to the piston inside the viscous medium injection cylinder (6).

6. The double-layer pneumatic pressure ring device for forming annular thin-walled parts with viscous media according to claim 2, characterized in that, The lower pressure edge ring (32) is disposed on the viscous medium chamber (5). During the viscous medium forming process, the lower pressure edge ring (32) also acts as a sealing ring.

7. The double-layer pneumatic pressure ring device for forming annular thin-walled parts with viscous media according to claim 1, characterized in that, The viscous medium (4) is methyl vinyl silicone rubber with a molecular weight of 600 kg / mol; the loading pressure of the viscous medium (4) is 600 MPa.

8. The double-layer pneumatic pressure ring device for forming annular thin-walled parts with viscous media according to claim 1, characterized in that, The diameter of the plate blank (2) is 850 mm and the thickness is 1.0 mm.

9. The working method of the double-layer pneumatic pressure ring device for forming annular thin-walled parts with viscous medium according to any one of claims 1-8, characterized in that, include: S1. In the initial state, the plate blank (2) is clamped between the die (1) and the viscous medium chamber (5). The upper pressure ring (31) is embedded in the hemispherical groove of the die (1), and the lower pressure ring (32) is embedded in the hemispherical groove of the viscous medium chamber (5). Both are in an uninflated state. S2. Gas is simultaneously injected into the upper pressure ring (31) and the lower pressure ring (32) through the pressure control system (10), causing them to expand and apply a uniform circumferential pressure force to the upper and lower surfaces of the sheet blank (2), and the pressure force is maintained until the forming process ends. S3. Control the action of the viscous medium pressure loading cylinder (8), drive the piston in the viscous medium injection cylinder (6) through the plunger (7), inject the viscous medium (4) into the viscous medium chamber (5) and make its pressure rise to the target loading pressure, thereby pushing the plate blank (2) to undergo plastic deformation and stick to the cavity of the die (1); S4. Under the combined action of constant viscous medium loading pressure and constant double-layer pneumatic edge pressing force, maintain for a period of time to complete the final forming of the plate blank (2); S5. After the molding is completed, the loading pressure of the viscous medium (4) is removed. Then, the gas in the upper pressure ring (31) and lower pressure ring (32) is released through the pressure control system (10) to release the pressure force. Finally, the mold is opened and the molded part is taken out.

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