A vacuum superplastic forming / diffusion bonding equipment

Abstract

The present invention provides a vacuum superplastic forming / diffusion bonding equipment for manufacturing complex components in the aerospace field. It includes a superplastic forming equipment main body, a vacuum acquisition system and an argon rapid cooling system. The vacuum acquisition system is composed of two sets of three-stage pump groups, which can achieve the required working vacuum degree, thereby providing a vacuum environment for forming the workpiece. The argon rapid cooling system can quickly cool down to avoid deformation of the workpiece. The equipment has the characteristics of light weight, high speed, precision and high reliability, and is suitable for the forming and manufacturing of various materials, and has broad application prospects. The present invention is expected to make up for the lag in my country's research and development and production of vacuum superplastic forming equipment, and promote the development of advanced manufacturing technology in my country's aerospace field.

Description

Technical Field

[0001] The present invention belongs to the field of aerospace, in particular to the field of vacuum superplastic forming / diffusion bonding technology. Background Art

[0002] In the aerospace field, extremely high requirements are placed on the lightweight, high-speed, precise and high-reliability forming and welding equipment and process technologies for complex parts. To achieve these requirements, advanced forming and welding equipment and related process technologies are needed. Among them, superplastic forming / diffusion bonding is a technology with broad application prospects. Under certain pressure and temperature conditions, superplastic forming can significantly improve the ductility and forming ability of materials, making it possible to form complex components while also having the advantages of high forming accuracy and high diffusion bonding quality. Compared with ordinary superplastic forming technology, vacuum superplastic forming technology has unique advantages in high-temperature oxidation of materials and purification of the forming process.

[0003] Traditional superplastic forming / diffusion bonding equipment operates under high temperature and high pressure during the manufacturing process, resulting in susceptibility to workpiece oxidation, poor surface quality, low forming precision, and long cooling times. This can easily lead to thermal deformation of the workpiece, which in turn affects the performance of the formed part. These issues also result in low part yields, which in turn leads to low production efficiency, making it impossible to meet the needs of mass production and increasing manufacturing costs. Summary of the Invention

[0004] The vacuum superplastic forming / diffusion bonding equipment provided by the present invention overcomes the shortcomings of traditional equipment such as difficulty in forming in a vacuum environment, easy oxidation of the workpiece, and inability to cool down quickly after forming. By adopting a vacuum system, the equipment can significantly increase the pumping rate, reduce the forming time, create a stable vacuum forming environment, improve the environment of superplastic forming parts, and avoid oxidation problems. At the same time, through the argon rapid cooling system, the workpiece can be quickly cooled, thereby effectively preventing thermal deformation of the workpiece, enhancing material properties, and improving forming quality and precision. These advantages make the present invention have a wide range of application prospects, and it is particularly suitable for lightweight and complex structure forming and manufacturing of high-temperature resistant materials such as titanium alloys, aluminum alloys, and high-temperature alloys.

[0005] The technical solutions provided by the present invention are as follows:

[0006] A vacuum superplastic forming / diffusion bonding equipment comprises a superplastic forming equipment body, a vacuum obtaining system, an argon gas rapid cooling system, and a transition water jacket.

[0007] The main body of the superplastic forming equipment includes a main frame, an upper pressure head, a lower platform, a lower top cylinder, a furnace body, a vacuum insulation screen, a heating belt, and an air pressure loading system.

[0008] The transition water jacket adopts a double-layer structure of inner and outer walls and a spiral rising cooling water channel. Water enters the lower water inlet, flows along the water channel, and is then discharged from the upper water outlet. A horizontal windshield is set inside the transition water jacket chamber.

[0009] The vacuum acquisition system includes two sets of three-stage vacuum pump groups, and the three-stage vacuum pump groups include a high vacuum diffusion pump + a medium vacuum Roots pump group + a roughing pump group.

[0010] The vacuum system further comprises a high vacuum pneumatic baffle valve, a low vacuum pneumatic baffle valve, a front-stage pneumatic vacuum baffle valve, a maintaining valve, a maintaining pump, and an adjustable pipeline.

[0011] The argon rapid cooling system includes an argon heat exchange device and an argon filling valve.

[0012] The main frame includes a column, an upper crossbeam, and a lower base. The upper crossbeam is provided with one or more hydraulic cylinders, and the lower platform is located on the lower base.

[0013] Furthermore, there are one or more upper pressure heads connected to corresponding hydraulic cylinders.

[0014] Furthermore, the lower platform has one or more partitions.

[0015] Furthermore, the lower top cylinder is located at the center of the lower platform and the center of each partition.

[0016] Furthermore, the furnace body is connected to a pipeline of a gas loading system to provide gas pressure for the workpiece.

[0017] Furthermore, one to several layers of vacuum insulation screens are arranged inside the furnace body.

[0018] Furthermore, the heating belt is fixed to the inner wall of the innermost vacuum insulation screen.

[0019] Furthermore, a cold trap is provided on the air inlet of the high vacuum diffusion pump, the high vacuum pneumatic baffle valve is located on the pipeline between the cold trap and the furnace body, and the pipeline is a double-layer transition water jacket with the water inlet at the bottom and the water outlet at the top; the low vacuum pneumatic baffle valve is located on the pipeline between the medium vacuum Roots pump group and the high vacuum pneumatic baffle valve; the front-stage pneumatic baffle valve is located on the pipeline between the medium vacuum Roots pump group and the exhaust port of the high vacuum diffusion pump; the maintaining valve is located on the pipeline between the air inlet of the maintaining pump and the exhaust port of the high vacuum diffusion pump.

[0020] The connecting pipeline is further described as an adjustable pipeline, and by adjusting the length of the adjustable pipeline, the impact caused by dimensional deviation can be accurately solved.

[0021] Furthermore, the argon heat exchange device includes an air inlet and an air outlet. One end of the argon charging valve is connected to the transition pipe sleeve, and the other end is connected to the argon storage tank to charge argon into the furnace body.

[0022] Furthermore, the argon pressure in the furnace is 0.5-0.9 MPa. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is an assembly diagram of the vacuum superplastic forming / diffusion bonding equipment of the present invention;

[0024] Figure 2 A diagram of a transition water jacket of the vacuum superplastic forming / diffusion bonding equipment of the present invention;

[0025] Figure 3 This is a diagram of the argon gas rapid cooling system of the vacuum superplastic forming / diffusion bonding equipment of the present invention;

[0026] In the figure: 1-superplastic forming equipment body, 11-main frame, 110-lower base, 111-column, 112-upper beam, 114-hydraulic cylinder, 12-upper pressure head, 13-lower platform, 14-lower top cylinder, 15-furnace body, 16-vacuum insulation screen, 17-heating belt, 19-air pressure loading system, 2-vacuum acquisition system, 201-high vacuum diffusion pump, 202-medium vacuum Roots pump unit, 203-roughing pump unit, 204-cold trap, 205-high vacuum pneumatic damper valve, 206-low vacuum pneumatic damper valve, 207-fore-stage pneumatic damper valve, 208-maintenance valve, 209-maintenance pump, 210-adjustable pipeline, 3-argon fast cooling system, 31-argon heat exchange device, 32-argon charging valve, 33-air outlet, 34-air inlet, 4-transition water jacket, 41-cooling water channel, 42-wind shield, 43-water inlet, 44-water outlet. DETAILED DESCRIPTION

[0027] The present invention will be described clearly and completely below with reference to the accompanying drawings. Obviously, the described embodiments are only some examples of the present invention, rather than all embodiments.

[0028] In the vacuum superplastic forming / diffusion bonding equipment of the present invention, some directional words are used for the convenience of description. For example, the directions or positional relationships indicated by "up", "down", "left", "right", etc. are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of description and do not refer to the specific positions that the device or components must have. Therefore, they cannot be understood as limitations on the present invention.

[0029] See also Figure 1According to one embodiment of the present invention, a vacuum superplastic forming / diffusion bonding device is disclosed, which includes a superplastic forming device body 1, a vacuum obtaining system 2, an argon gas rapid cooling system 3, and a transition water jacket 4. In this embodiment, the superplastic forming device body includes a main frame 11, an upper pressure head 12, a lower platform 13, a lower top cylinder 14, a furnace body 15, a vacuum heat insulation screen 16, a heating belt 17, and an air pressure loading system 19. The main frame is composed of a lower base 110 as the main frame base, four columns 111 as support, and an upper crossbeam 112 with four hydraulic cylinders 114. A single hydraulic cylinder has an adjustable tonnage of 5 to 500 tons. It can work as a single cylinder or multiple cylinders can work in coordination, accurately controlling the loading pressure within 1% to achieve multi-mode forming. The hydraulic cylinder is connected to the upper pressure head 12. Mounted on the lower base 110 is a lower platform 13, divided into multiple zones. This multi-zone arrangement effectively prevents thermal expansion of the platform material at high temperatures, which can lead to cracking. Lower ejector cylinders 14 are located at the center of the lower platform 13 and at the centers of multiple zones. These cylinders apply reverse pressure to the part for pre-forming and ejection from the mold. The furnace body 15 rests on the lower base 110, with the lower platform 13 located at the center of the lower flange of the furnace body 15. The inner wall of the furnace body is equipped with seven layers of vacuum insulation shields 16, with the inner four layers made of molybdenum alloy and the outer three layers of stainless steel. Each layer is 0.3 to 0.5 mm thick. These multiple layers effectively reduce heat loss, improve radiant heating efficiency, and prevent oxidation of the furnace body's external materials and damage to components at high temperatures. The innermost vacuum insulation shield 16 is lined with an arcuate molybdenum alloy heating band 17, maintaining a forming temperature above 1300°C.

[0030] The transition water jacket 4 has a double-layer structure of inner and outer walls, and a spiral ascending cooling water channel 41 is arranged between the inner and outer walls. Water enters the lower water inlet 43 and flows along the water channel, and is then discharged from the upper water outlet 44. The flowing circulating water flow takes away the heat in the pipeline, which can improve the cooling effect and avoid affecting the stability and life of the equipment due to overheating. An argon inflation valve 32 is installed on the lower wall of the transition water jacket 4, and a horizontal wind shield 42 is arranged inside the chamber of the transition water jacket 4, which plays a diversion role when filling with argon and improves the cooling efficiency. One end of the transition water jacket 4 is connected to the superplastic forming equipment furnace body 15, and the other end is connected to the vacuum acquisition system 2.

[0031] The vacuum acquisition system 2 includes two sets of three-stage vacuum pump groups on the left and right. Each set of three-stage vacuum pump groups includes a high vacuum diffusion pump 201 + a medium vacuum Roots pump group 202 + a roughing pump group 203. The upper end of the high vacuum diffusion pump inlet is connected to a cold trap 204, and the other end of the cold trap is connected to a high vacuum pneumatic damper valve 205. The cold trap mainly uses a low-temperature surface to condense and capture gas molecules with a condensation point temperature higher than the cold trap temperature, thereby improving the efficiency of vacuuming and reducing the entry of harmful gases into the pump body to extend the service life of the vacuum pump. The low vacuum pneumatic damper valve 206 is located on the pipeline between the medium vacuum Roots pump group 202 and the high vacuum pneumatic damper valve 205, and is mainly used for vacuum degrees ≥1000 Pa is used to evacuate the furnace body; the front-stage pneumatic baffle valve 207 is located on the pipeline between the medium-vacuum Roots pump group 202 and the exhaust port of the high-vacuum diffusion pump 201, and the front-stage pneumatic baffle valve 207 and the high-vacuum pneumatic baffle valve 205 are used in conjunction with each other to evacuate the furnace body to a high vacuum when the vacuum degree is less than 1000Pa; the maintaining valve 208 is located on the pipeline between the air inlet of the maintaining pump and the exhaust port of the high-vacuum diffusion pump, and the maintaining valve cooperates with the maintaining pump 209 to evacuate the diffusion pump chamber, maintain the internal vacuum degree of the diffusion pump below 5Pa, and prevent the diffusion pump from oxidation. In addition, during the cooling process, a low-power maintaining pump is used to ensure the vacuum degree, which can effectively save energy.

[0032] The pipes between the pump groups are adjustable pipes 210 with adjustable lengths, which can accurately solve the assembly difficulty problem caused by size deviation.

[0033] The argon rapid cooling system is used to quickly cool down the workpiece, and mainly includes an argon heat exchange device 31, whose air outlet 33 and air inlet 34 are respectively connected to the upper end of the furnace body and the lower end of the transition water jacket. When argon is filled and the gas fills the interior of the furnace cavity, the argon rapid cooling device 31 is turned on, and the air inlet 34 of the argon heat exchange device 31 inhales hot air and cools it, and then enters the interior of the furnace body from the air outlet 33 to quickly cool the chamber.

[0034] In the solution provided in the embodiment of the present application, the present invention adopts multiple sets of molybdenum belt heating and multi-layer heat shield radiation to significantly improve the heating efficiency, shorten the time of empty furnace heating to 1200℃ by 50%, and improve the furnace temperature control accuracy from ±10℃ to ±1℃. Two sets of three-stage vacuum pumps are used, 20m 3 The following vacuum chamber can reach 10 in 20 minutes -3 Pa-level vacuum, vacuum efficiency increased by 30%. Using an argon rapid cooling system, cooling from 700°C to room temperature takes ≤5 hours, increasing cooling efficiency by over 50%.

[0035] Taking the aluminum-lithium alloy superplastic forming / diffusion bonding aircraft skin as an example, the surface accuracy of this embodiment is improved from the original ±1mm to ±0.3mm; the tensile strength is increased from 450MPa to 520MPa, an increase of 16%; the average hydrogen and oxygen content is reduced, the average hydrogen content is ≤0.018%, and the average oxygen content is ≤0.25%; the vacuum environment greatly improves the oxidation of the workpiece, and the workpiece qualification rate is increased from 70% to 90%.

[0036] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed by the present invention should be covered by the scope of protection of the present invention.

Claims

1. A vacuum superplastic forming / diffusion bonding equipment, characterized in that: It includes a superplastic forming equipment body, a vacuum obtaining system, an argon rapid cooling system, and a transition water jacket. The superplastic forming equipment body includes a main frame, an upper pressure head, a lower platform, a lower top cylinder, a furnace body, a vacuum insulation screen, a heating belt, and an air pressure loading system. The transition water jacket has a double-layer structure with an inner wall and an outer wall, and a spiral rising cooling water channel is provided between the inner wall and the outer wall, with a water inlet at the bottom and a water outlet at the top, and a windshield is provided inside the transition water jacket chamber; the main body of the superplastic forming equipment is connected to the vacuum acquisition system through the transition water jacket; the vacuum acquisition system comprises two sets of three-stage vacuum pump groups; the three-stage vacuum pump groups comprise a high vacuum diffusion pump + a medium vacuum Roots pump group + a roughing pump group, and the vacuum acquisition system further comprises a high vacuum pneumatic baffle valve, a low vacuum pneumatic baffle valve, a front-stage vacuum pneumatic baffle valve, a maintaining valve, a maintaining pump, and an adjustable pipeline; the argon gas fast cooling system comprises an argon gas heat exchange device and an argon gas charging valve; The main frame includes a column, an upper crossbeam, and a lower base. The upper crossbeam is equipped with one or more hydraulic cylinders, and the lower platform is placed on the lower base.

2. The vacuum superplastic forming / diffusion bonding equipment according to claim 1, characterized in that: There are one or more upper pressure heads connected to corresponding hydraulic cylinders.

3. The vacuum superplastic forming / diffusion bonding equipment according to claim 1, characterized in that: The lower platform is composed of one or more partitions, and the lower top cylinder is located at the center of the lower platform and the center of each partition.

4. The vacuum superplastic forming / diffusion bonding equipment according to claim 1, characterized in that: The furnace body is internally connected to a pipeline of an air pressure loading system to provide air pressure for forming the workpiece.

5. The vacuum superplastic forming / diffusion bonding equipment according to claim 1, characterized in that: One to several layers of vacuum heat insulation screens are arranged inside the furnace body. The heat insulation screens are made of molybdenum alloy or stainless steel, and the thickness of a single layer is 0.3 to 0.5 mm.

6. The vacuum superplastic forming / diffusion bonding equipment according to claim 1, characterized in that: The heating belt is fixed to the inner wall of the innermost vacuum insulation screen.

7. The vacuum superplastic forming / diffusion bonding equipment according to claim 1, characterized in that: A cold trap is provided on the air inlet of the high vacuum diffusion pump, and the high vacuum pneumatic baffle valve is located on the pipeline between the cold trap and the furnace body, and the pipeline is a water jacket with an inner and outer double-layer structure, with the water inlet at the bottom and the water outlet at the top; the low vacuum pneumatic baffle valve is located on the pipeline between the medium vacuum Roots pump group and the high vacuum pneumatic baffle valve; the front-stage pneumatic baffle valve is located on the pipeline between the medium vacuum Roots pump group and the exhaust port of the high vacuum diffusion pump; the maintaining valve is located on the pipeline between the air inlet of the maintaining pump and the exhaust port of the high vacuum diffusion pump.

8. The vacuum superplastic forming / diffusion bonding equipment according to claim 1, characterized in that: The number of the adjustable pipelines is one or more, and by adjusting the length of the adjustable pipelines, assembly difficulties caused by size deviations can be accurately resolved.

9. The vacuum superplastic forming / diffusion bonding equipment according to claim 1, characterized in that: The argon heat exchange device includes an air inlet and an air outlet. One end of the argon charging valve is connected to the transition pipe sleeve, and the other end is connected to the argon gas storage tank for charging argon into the furnace body.

10. The vacuum superplastic forming / diffusion bonding equipment according to claim 9, characterized in that: The pressure of argon gas filled into the rapid cooling furnace is 0.5-0.9 MPa.

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