A forming device and method for grading-pressing a thin-walled large-angle corrugated ring segment

Abstract

This invention discloses a forming apparatus for graded pressing of thin-walled, large-angle corrugated ring segments, relating to the field of metal corrugated pipe forming. It includes a forming machine and pre-pressing components and forming pressing molds arranged on the forming machine. The pre-pressing component includes multiple pre-pressing molds arranged sequentially near the forming pressing molds. Each pre-pressing mold includes an upper pre-pressing mold and a lower pre-pressing mold. The top of the lower pre-pressing mold has a pre-pressed corrugated ring segment groove, and the bottom of the upper pre-pressing mold has a pre-pressed corrugated ring segment body fixed thereon. The forming pressing mold includes an upper forming mold and a lower forming mold. The top of the lower forming mold has a forming corrugated ring segment groove, and the bottom of the upper forming mold has a forming corrugated ring segment body fixed thereon. The large-angle corrugated ring segment blanks formed by the multiple pre-pressing molds gradually approach the standard large-angle corrugated ring segment. Through multi-stage progressive forming, the deformation of the arc-shaped blank is evenly distributed in each pressing stage, significantly reducing the incidence of defects such as corrugation cracking, circumferential wrinkling, and non-adherence to the mold.

Description

Technical Field

[0001] This invention relates to the field of metal corrugated pipe forming, specifically to a forming apparatus and method for graded pressing of thin-walled, large-angle corrugated ring segments. Background Technology

[0002] Metal bellows, as a key flexible compensation structure, is widely used in high-end equipment fields such as nuclear power, petrochemicals, and aerospace. It is a core component of the ACP100 reactor cavity sealing sleeve and the flexible connector of the pressure vessel, requiring radial expansion compensation capability and stringent sealing precision. In the prototype of the flexible reactor cavity sealing sleeve, the upper end of the sleeve connects to the steel cladding of the reactor water pool, and the lower end connects to the pressure vessel cylinder support block; both connections are made by welding. The reactor cavity sealing sleeve mainly consists of three parts: an adjustment assembly, a sealing ring assembly, and a lower connecting assembly. The lower connecting assembly, designed as a ring-shaped corrugated metal pipe to absorb radial expansion, is specifically designed as such. Metal bellows are generally made of difficult-to-deform materials such as stainless steel, nickel-based alloys, and titanium alloys, and they present a structural contradiction of "large diameter - thin wall - high corrugation," making them prone to defects such as wrinkling, cracking, and non-adherence to the mold during the forming process. Currently, the forming of thin-walled, large-angle corrugated rings for metal bellows generally adopts a single molding method, lacking a dynamic adaptation mechanism. This requires applying a large pressing force to the arc-shaped blank to form the large-angle corrugated ring in one step. For high-corrugation (H≥150mm) and extremely thin-walled (t≤2mm) components, one-time large deformation pressing can easily lead to stress concentration, causing corrugation cracking or circumferential wrinkling. Secondly, currently, after the arc-shaped blank has completed the processing of the thin-walled, large-angle corrugated ring, an offline detection mode is used. That is, after forming, dimensional deviations are detected by image recognition and manual measurement, which cannot provide real-time feedback on the amount of corrugation springback and surface defects during the forming process. Because the springback of thin-walled components is strongly coupled with the pressing force and temperature, the lag caused by offline detection makes it difficult to adjust process parameters, resulting in a low finished product qualification rate and easy difficulties in subsequent assembly and welding due to excessive springback. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a forming apparatus and method for graded pressing of thin-walled, large-angle corrugated ring segments, thereby solving the deficiencies of the prior art.

[0004] The objective of this invention is achieved through the following technical solution: a forming device for graded pressing of thin-walled, large-angle corrugated ring segments, comprising a forming machine base and a pre-pressing assembly and a forming pressing mold arranged on the forming machine base. The pre-pressing assembly includes multiple pre-pressing molds arranged sequentially near the forming pressing mold. The pre-pressing mold includes an upper pre-pressing mold and a lower pre-pressing mold. The top of the lower pre-pressing mold has a pre-pressed corrugated ring segment groove. The upper pre-pressing mold is positioned directly above the lower pre-pressing mold. A pre-pressed corrugated ring segment body is fixed to the bottom of the upper pre-pressing mold. A large-angle corrugated ring segment blank is formed on the arc-shaped ring segment blank through the cooperation of the pre-pressed corrugated ring segment body and the pre-pressed corrugated ring segment groove. The forming pressing mold includes an upper forming mold, a lower forming mold, and a corrugated ring segment detection mold. The top of the lower forming mold has a forming corrugated ring segment groove. The upper forming mold is positioned directly above the lower forming mold. A corrugated ring segment body is fixed at the bottom. The large-angle corrugated ring segment blank is pressed into a standard large-angle corrugated ring segment by the cooperation of the corrugated ring segment body and the corrugated ring segment groove. The large-angle corrugated ring segment blanks formed by multiple pre-pressing molds gradually approach the standard large-angle corrugated ring segment. A corrugated ring segment detection body is formed on the corrugated ring segment detection mold. Multiple detection components are arranged on the inner and outer sides of the corrugated ring segment detection body along its own trajectory direction. The detection components on both sides of the corrugated ring segment detection body are staggered along its own trajectory direction. The detection component includes a detection probe and a detection spring. A detection cavity is provided in the corrugated ring segment detection mold. Multiple detection holes communicating with the detection cavity are opened on both sides of the corrugated ring segment detection body. Each detection probe corresponds to a detection hole. The detection probe is set in the detection cavity, and one end of the detection probe protrudes from the detection hole.

[0005] Furthermore, the lower forming mold has lower heating holes on both its inner and outer sides, and a first heating rod is fixed in the lower heating hole. The upper forming mold has upper heating holes on both its inner and outer sides, and a second heating rod is fixed in the upper heating hole. Both the second heating rod and the first heating rod are wound with resistance heating wires.

[0006] Furthermore, the forming and pressing mold also includes a rotary switching body, which is rotatably installed with its rotation axis set horizontally. The upper forming mold is installed at the bottom of the rotary switching body, and the corrugated ring segment detection mold is installed on one side of the rotary switching body. The rotary switching body deflects the corrugated ring segment or the corrugated ring segment detection body to correspond to the corrugated ring segment groove. A spring plate is fixed to the other end of the detection probe, and the detection spring is sleeved on the detection probe. The two ends of the detection spring are respectively connected to the spring plate and the corrugated ring segment detection body.

[0007] Furthermore, the detection assembly also includes a laser rangefinder sensor, a reflector plate is fixed to the side wall of the spring disc, the laser rangefinder sensor is installed in the detection cavity and is located above the corrugated ring segment detection body, and the reflector plate is located on the detection path of the laser rangefinder sensor.

[0008] Furthermore, the lower forming mold is provided with negative pressure cavities on both sides of the forming corrugated annular groove. The negative pressure cavities are connected to the forming corrugated annular groove through a plurality of negative pressure holes. The plurality of negative pressure holes are spaced apart along the arc trajectory direction of the lower forming mold. The lower forming mold is equipped with a negative pressure pump, and the negative pressure pump is connected to the negative pressure cavities through a negative pressure pipe.

[0009] Furthermore, the negative pressure cavity contains a sealing assembly, which includes an arc-shaped sealing plate and a sealing rod. The arc-shaped sealing plate has the freedom to move radially along the lower mold. Each negative pressure hole corresponds to a sealing rod, which is fixed to the arc-shaped sealing plate and can be inserted into the negative pressure hole. The end of the sealing rod away from the arc-shaped sealing plate is attached to the inner wall of the lower mold to form a complete molding corrugated annular groove.

[0010] Furthermore, an electromagnetic drive mechanism is provided at the end of the arc-shaped sealing plate away from the sealing rod, and a hydraulic drive mechanism is provided at the end of the arc-shaped sealing plate away from the sealing rod. The hydraulic drive mechanism includes a sealing hydraulic cylinder, the cylinder body of which is installed on the outer wall of the lower forming mold, and the telescopic rod of which moves into the negative pressure cavity to connect to the arc-shaped sealing plate.

[0011] Furthermore, a frame is fixed on the molding machine platform, and the molding pressing mold also includes a molding hydraulic cylinder and a lifting bearing seat. The molding hydraulic cylinder is vertically mounted on the frame, and the telescopic shaft of the molding hydraulic cylinder is connected to the lifting bearing seat. A U-shaped opening is provided at the bottom of the lifting bearing seat, and a switching shaft is provided in the U-shaped opening. The switching shaft is rotatably connected to the lifting bearing seat. A switching shaft seat is fixed at the top of the rotating switching body, and the switching shaft seat is fixedly sleeved on the switching shaft. A motor is installed on the side wall of the lifting bearing seat, and the output shaft of the motor is connected to the switching shaft through a coupling.

[0012] Furthermore, the pre-pressing mold also includes a pre-pressing hydraulic cylinder and a pre-pressing lifting seat. The pre-pressing hydraulic cylinder is vertically mounted on the frame, and the telescopic shaft of the pre-pressing hydraulic cylinder is connected to the pre-pressing lifting seat. The upper forming mold is mounted on the bottom of the pre-pressing lifting seat via a screw.

[0013] A method for forming thin-walled, large-angle corrugated ring segments by graded pressing, using the aforementioned apparatus for forming thin-walled, large-angle corrugated ring segments, includes the following steps: S1. Load the arc-shaped blank onto the forming machine table; S2. The arc-shaped ring section blank is first processed on the arc-shaped blank by multiple pre-pressing dies. The order of use of multiple pre-pressing dies satisfies the requirement to gradually bring the large-angle corrugated ring section blank closer to the standard large-angle corrugated ring section forming. S3. Then, use a forming and pressing mold to process the arc-shaped ring blank, so that standard large-angle corrugated segments are formed on the arc-shaped ring blank. S4. Use multiple detection components to detect the large-angle corrugated section of the arc-shaped ring blank to obtain the springback amount of the large-angle corrugated section; when the springback amount is within the error range, the processing is completed and the arc-shaped ring blank is cut; when the springback amount exceeds the error range, proceed to the next step. S5. Increase the pressing pressure and molding temperature, and process the arc-shaped ring blank again through the molding pressing mold; S6. The springback amount of the large-angle corrugated section is detected by the detection component. When the springback amount is within the error range, the processing is completed and the arc-shaped ring section blank is cut. When the springback amount exceeds the error range, the operation of S5 above is repeated.

[0014] The beneficial effects of this invention are: 1. By using multiple pre-pressing dies arranged sequentially along the forming path, a multi-stage progressive forming method is achieved. The corrugated blank shape of each pre-pressing die gradually approaches the standard large-angle corrugated ring segment from its initial state, ensuring that the deformation of the arc-shaped blank is evenly distributed in each pressing stage. This avoids the stress concentration problem caused by a large deformation at one time in traditional single-molding processes. For difficult-to-deform components with high corrugation (H≥150mm) and extremely thin walls (t≤2mm), this tiered mechanism can effectively disperse forming stress and significantly reduce the incidence of defects such as corrugation cracking, circumferential wrinkling, and non-adherence to the mold. Combined with the final pressing and shaping of the forming die, the forming qualification rate of thin-walled large-angle corrugated ring segments is greatly improved.

[0015] 2. By integrating a corrugated ring segment detection mold through a rotating switching body, the system can be immediately switched to the detection station after molding. Utilizing a combined detection structure of "detection probe + laser rangefinder," online and precise detection of the corrugated ring segment is achieved. The detection probe directly contacts the corrugated surface, and the laser rangefinder, in conjunction with a reflector, collects probe displacement data in real time, accurately measuring the springback of large-angle corrugated ring segments. This allows for timely adjustment of the molding pressure and temperature of the molding die based on the springback amount. Compared to the lag in traditional offline detection, this invention achieves a closed-loop linkage of "molding-detection-parameter adjustment." Based on the real-time detected springback amount, the molding pressure and temperature can be dynamically optimized, precisely offsetting the springback effect of thin-walled components. This significantly improves the molding accuracy of thin-walled, large-angle corrugated ring segments, effectively avoiding subsequent assembly and welding difficulties caused by excessive springback, and ensuring the assembly accuracy and sealing performance of core components such as sealing sleeves. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of a molding device for graded pressing of thin-walled, large-angle corrugated ring segments according to the present invention. Figure 1 ; Figure 2 This is a schematic diagram of the structure of a molding device for graded pressing of thin-walled, large-angle corrugated ring segments according to the present invention. Figure 2 ; Figure 3 This is a schematic diagram of the structure of a molding device for graded pressing of thin-walled, large-angle corrugated ring segments according to the present invention. Figure 3 ; Figure 4 This is a schematic diagram of the internal structure of the corrugated ring segment detection mold in the forming device for graded pressing of thin-walled large-angle corrugated ring segments according to the present invention. Figure 5 This is a schematic diagram of the internal structure of the lower forming die in a forming device for graded pressing of thin-walled, large-angle corrugated ring segments according to the present invention. Figure 1 ; Figure 6 This is a schematic diagram of the internal structure of the lower forming die in a forming device for graded pressing of thin-walled, large-angle corrugated ring segments according to the present invention. Figure 2 ; Figure 7 This is a cross-sectional view of the lower die in the forming device for graded pressing of thin-walled large-angle corrugated ring segments according to the present invention. Figure 8 for Figure 2 Enlarged view of point A in the middle; Figure 9 for Figure 3 Enlarged view at point B in the middle; In the diagram, 1-forming machine base, 2-pre-compression upper mold, 3-pre-compression lower mold, 4-pre-compression corrugated ring groove, 5-pre-compression corrugated ring body, 6-forming upper mold, 7-forming lower mold, 8-forming corrugated ring groove, 9-forming corrugated ring body, 10-lower heating hole, 11-first heating rod, 12-upper heating hole, 13-second heating rod, 14-resistance heating wire, 15-rotation switching body, 16-corrugated ring detection mold, 17-corrugated ring detection body, 18-detection probe, 19-detection spring, 20-detection cavity, 21-detection hole, 22-spring disc. 23-Laser rangefinder sensor, 24-Reflector, 25-Negative pressure cavity, 26-Negative pressure hole, 27-Arc-shaped sealing plate, 28-Sealing rod, 29-Sealing hydraulic cylinder, 30-Arc-shaped air cushion, 31-Avoidance through hole, 32-Lifting shaft, 33-Shaft push plate, 34-Frame, 35-Forming hydraulic cylinder, 36-Lifting bearing seat, 37-Switching shaft, 38-Switching shaft seat, 39-Motor, 40-Pre-pressure hydraulic cylinder, 41-Pre-pressure lifting seat, 42-Push plate hydraulic cylinder, 43-Lifting groove, 44-Push plate mounting cavity, 45-Lifting inclined surface, 46-Lifting ball. Detailed Implementation

[0017] Example 1 like Figures 1 to 9As shown, a forming device for graded pressing of thin-walled, large-angle corrugated ring segments includes a forming machine base 1 and a pre-pressing assembly and a forming pressing mold arranged on the forming machine base 1. The pre-pressing assembly includes multiple pre-pressing molds arranged sequentially near the forming pressing mold. The pre-pressing mold includes a pre-pressing upper mold 2 and a pre-pressing lower mold 3. The top of the pre-pressing lower mold 3 has a pre-pressing corrugated ring segment groove 4. The pre-pressing upper mold 2 is located directly above the pre-pressing lower mold 3. A pre-pressing corrugated ring segment body 5 is fixed to the bottom of the pre-pressing upper mold 2. The large-angle corrugated ring segment blank is formed on the arc-shaped ring segment blank by the cooperation between the pre-pressing corrugated ring segment body 5 and the pre-pressing corrugated ring segment groove 4. The forming pressing mold includes a forming upper mold. 6 and forming lower die 7, the top of forming lower die 7 has a forming corrugated ring segment groove 8, forming upper die 6 is set directly above forming lower die 7, and forming corrugated ring segment body 9 is fixed at the bottom of forming upper die 6. Through the cooperation of forming corrugated ring segment body 9 and forming corrugated ring segment groove 8, the large-angle corrugated ring segment blank is pressed into a standard large-angle corrugated ring segment. The large-angle corrugated ring segment blank formed by multiple pre-pressing dies gradually approaches the standard large-angle corrugated ring segment, that is, along the direction close to the forming pressing die, the angle of the side wall of the pre-pressing corrugated ring segment groove 4 of multiple pre-pressing lower dies 3 relative to the horizontal plane gradually increases. The specific production process of its thin-walled large-angle corrugated ring segment is as follows: the arc-shaped blank is... The material is fed onto the forming machine 1, and multiple pre-pressing components are used sequentially along the direction close to the forming and pressing mold to initially press and shape the arc-shaped blank. This is used to process a large-angle corrugated ring segment blank on the arc-shaped blank. The specific forming method of the large-angle corrugated ring segment blank is as follows: the arc-shaped blank is placed on the top surface of the pre-pressing lower mold 3, the pre-pressing upper mold 2 moves close to the pre-pressing lower mold 3 to complete the mold closing action, and the arc-shaped blank is partially pressed into the pre-pressing corrugated ring segment groove 4 by the pre-pressing corrugated ring segment body 5, thereby processing a large-angle corrugated ring segment blank on the arc-shaped blank. The large-angle corrugated ring segment blank is gradually pressed close to the standard large-angle corrugated ring segment by multiple pre-pressing components, and then formed. The pressing die processes the large-angle corrugated ring blank into a standard large-angle corrugated ring. The specific forming method of the large-angle corrugated ring is as follows: the large-angle corrugated ring blank of the arc-shaped blank is placed into the forming corrugated ring groove 8 of the forming lower die 7, and then the forming upper die 6 moves close to the forming lower die 7, so that the forming corrugated ring body 9 fits in the forming corrugated ring groove 8, thereby pressing the large-angle corrugated ring blank into a standard large-angle corrugated ring. In this way, the thin-walled large-angle corrugated ring is processed through a multi-stage step-by-step forming method, so that the deformation of the arc-shaped blank is evenly distributed in each pressing stage, avoiding the stress concentration problem caused by a large deformation at one time in the traditional single molding process.For difficult-to-deform components with high corrugation (H≥150mm) and extremely thin walls (t≤2mm), this grading mechanism can effectively disperse forming stress and significantly reduce the incidence of defects such as corrugation cracking, circumferential wrinkling, and non-adherence to the mold. Combined with the final pressing and shaping of the forming die, the forming pass rate of thin-walled, large-angle corrugated ring segments is greatly improved. It is particularly suitable for the forming requirements of difficult-to-deform materials such as stainless steel and nickel-based alloys, and fully meets the stringent forming requirements of nuclear-grade components such as the ACP100 reactor cavity sealing sleeve. In practice, two or four large-angle corrugated ring segments can generally be welded into a complete annular corrugation, and multiple annular corrugations are welded axially to obtain a metal bellows.

[0018] Example 2 Based on Example 1, in order to facilitate the positioning of the arc-shaped blank and to accurately feed the arc-shaped blank onto the pre-pressing lower die 3 and the forming lower die 7, limiting protrusions are fixed on both sides and both ends of the top surface of the pre-pressing lower die 3 and on both sides and both ends of the top surface of the forming lower die 7. By placing the arc-shaped blank within the space enclosed by the limiting protrusions, the accurate feeding of the arc-shaped blank can be achieved.

[0019] Example 3 Based on Example 2, such as Figure 1 , Figure 2 , Figure 3 , Figure 8 and Figure 9 As shown, the lower forming mold 7 has lower heating holes 10 on both its inner and outer sides, and a first heating rod 11 is fixed inside the lower heating hole 10. The upper forming mold 6 has upper heating holes 12 on both its inner and outer sides, and a second heating rod 13 is fixed inside the upper heating hole 12. Resistance heating wires 14 are wound around both the second heating rod 13 and the first heating rod 11. When using the forming and pressing mold, it is necessary to control the forming pressing force and forming pressing temperature of the upper forming mold 6 on the arc-shaped blank. The first heating rod 11 and the second heating rod 13 are heated by the resistance heating wires 14. The first heating rod 11 transfers heat to the lower forming mold 7, and the second heating rod 13 transfers heat to the upper forming mold 6, keeping the upper forming mold 6 and the lower forming mold 7 in a closed state, so that the temperature of the upper forming mold 6 and the lower forming mold 7 is 390-410℃. The time in the closed state at this temperature is not less than 3 hours to eliminate forming stress, greatly reduce the springback of the large-angle corrugated ring segment, and improve the forming accuracy of the thin-walled large-angle corrugated ring segment.

[0020] Example 4 In actual production, the stress in the large-angle corrugated rings cannot be completely eliminated due to factors such as molding temperature, the material of the arc-shaped blank, and external factors. This causes the large-angle corrugated rings of the arc-shaped blank to spring back to varying degrees. It is necessary to measure the dimensions of the large-angle corrugated rings. If the springback is within the allowable error range, it is considered a good product; if the springback exceeds the error range, it is considered a defective product and needs to be reworked and pressed again. Current inspection methods generally involve manual measurement or visual imaging. Manual measurement suffers from large errors and low efficiency. High-temperature arc-shaped blanks will form fog around them, affecting the clarity of visual imaging and also causing large measurement errors. Furthermore, both measurement methods require the arc-shaped blank to be cooled to room temperature. Defective products need to be re-molded using a molding die, requiring the arc-shaped blank to be reheated to the required temperature and maintained at that temperature for more than 3 hours. This results in a long rework cycle for the arc-shaped blank, affecting production efficiency. Therefore, based on Example 3, if... Figures 1 to 4As shown, the forming and pressing mold also includes a rotary switching body 15 and a corrugated ring segment detection mold 16. The rotary switching body 15 is rotatably mounted, and the rotation axis of the rotary switching body 15 is horizontally set. The upper forming mold 6 is installed at the bottom of the rotary switching body 15, and the corrugated ring segment detection mold 16 is installed on one side of the rotary switching body 15. A corrugated ring segment detection body 17 is formed on the corrugated ring segment detection mold 16. The rotary switching body 15 deflects the corrugated ring segment body 9 or the corrugated ring segment detection body 17 to correspond to the corrugated ring segment groove 8. Multiple detection components are arranged on the inner and outer sides of the corrugated ring segment detection body 17 along its own trajectory direction. The detection components on both sides of the corrugated ring segment detection body 17 are staggered along its own trajectory direction. The detection components include detection probes 18 and detection springs 19. The corrugated ring segment detection module 16 has a detection cavity 20. Multiple detection holes 21 communicating with the detection cavity 20 are opened on both sides of the corrugated ring segment detection body 17. Each detection probe 18 corresponds to one detection hole 21. The detection probe 18 is placed inside the detection cavity 20, with one end of the probe 18 protruding from the detection hole 21 and the other end of the probe 18 fixed to a spring plate 22. A detection spring 19 is sleeved on the detection probe 18, and both ends of the spring 19 are connected to the spring plate 22 and the corrugated ring segment detection body 17, respectively. The detection assembly also includes a laser range sensor 23. A reflector 24 is fixed to the side wall of the spring plate 22. The laser range sensor 23 is installed inside the detection cavity 20 and located within the corrugated ring segment detection body 17. Above, the reflector 24 is located on the detection path of the laser rangefinder 23. The rotation of the rotating switching body 15 switches the upper forming mold 6 and the corrugated ring detection mold 16 to the working state respectively. When the arc-shaped blank is pressed and formed, the upper forming mold 6 is located directly above the lower forming mold 7. The large-angle corrugated ring is formed by the closing of the upper forming mold 6 and the lower forming mold 7. After the upper forming mold 6 and the lower forming mold 7 are separated, the rotating switching body 15 rotates 90°, so that the corrugated ring detection mold 16 is located directly above the lower forming mold 7. The corrugated ring detection mold 16 drives the corrugated ring detection body 17 on it to move into the corrugated groove of the large-angle corrugated ring, so that the detection probe 18 contacts the inner wall of the corrugated groove. When the large-angle corrugated ring rebounds, it will push the detection probe. The tensile testing spring 19 moves into the testing cavity 20, causing the testing probe 18 to move the reflector 24. The laser range sensor 23 detects the front-to-back distance of the reflector 24, and the movement of the testing probe 18 is obtained through the difference in front-to-back distance. The movement of the testing probe 18 is the springback of the large-angle corrugated ring segment. The springback is compared with the error value to determine whether the accuracy of the large-angle corrugated ring segment meets the requirements. If it does not meet the requirements, the rotating switching body 15 rotates the upper forming mold 6 back to the working state, and the mold is closed again to press the large-angle corrugated ring segment, increasing the pressing force and forming temperature. Due to the increase in pressing force and forming temperature, it is not necessary to keep the mold closed for more than 3 hours; it is sufficient to keep it within 1 hour. After mold separation, the springback is tested again.If the sample passes inspection, the curved blank is cut to size; otherwise, the forming and pressing operation is repeated. Since the detection probe 18 can directly contact the inner wall of the corrugated groove, the displacement of the probe 18 is converted into the springback of the large-angle corrugated ring segment. Therefore, it is unaffected by the temperature of the curved blank and can complete the accuracy test without waiting for the curved blank to cool to room temperature. Curved blanks that fail inspection can be directly pressed again using the forming and pressing mold for correction. At this time, the curved blank still has a relatively high temperature, reducing the heating time and improving the detection accuracy and efficiency of the large-angle corrugated ring segment. The multiple detection components provide a large detection coverage area for the large-angle corrugated ring segment, accurately reflecting its springback value. Preferably, when the detection probe 18 contacts the inner wall of the corrugated groove, the detection spring 19 is stretched, causing the detection probe 18 to abut against the inside of the corrugated groove. This ensures that the detection probe 18 can move along with the rebound of the large-angle corrugated ring segment. The connection between the large-angle corrugated ring segment and the arc-shaped blank is an arc-shaped transition. When the corrugated ring segment detection body 17 enters the corrugated groove, the detection probe 18 first contacts the arc-shaped transition area. Guided by the arc-shaped surface, the detection probe 18 stretches the detection spring 19, allowing the detection probe 18 to smoothly enter the corrugated groove and contact the inner wall of the corrugated groove, thereby accurately detecting the rebound amount of the large-angle corrugated ring segment.

[0021] Furthermore, a frame 34 is fixed on the molding machine 1. The molding and pressing mold also includes a molding hydraulic cylinder 35 and a lifting bearing seat 36. The molding hydraulic cylinder 35 is vertically mounted on the frame 34. The telescopic shaft of the molding hydraulic cylinder 35 is connected to the lifting bearing seat 36. A U-shaped opening is provided at the bottom of the lifting bearing seat 36. A switching shaft 37 is provided inside the U-shaped opening. The switching shaft 37 is rotatably connected to the lifting bearing seat 36. A switching shaft seat 38 is fixedly mounted on the top of the rotating switching body 15. The switching shaft seat 38 is fixedly sleeved on the switching shaft 37. A motor 39 is mounted on the side wall of component 36. The output shaft of motor 39 is connected to switching shaft 37 via a coupling. This, in turn, drives rotating switching body 15 up and down via forming hydraulic cylinder 35, enabling the upper forming mold 6 and lower forming mold 7 to close and separate. This allows corrugated ring segment detection mold 16 to detect the springback of large-angle corrugated ring segments. Motor 39 drives switching shaft 37 to rotate, which in turn drives rotating switching body 15 via switching shaft seat 38, thus switching the working states of the upper forming mold 6 and corrugated ring segment detection mold 16. This integrated detection and forming process eliminates the intermediate conveying step of the curved blank and eliminates the need to cool the curved blank to room temperature and reheat it, significantly improving the production efficiency of thin-walled, large-angle corrugated ring segments.

[0022] Example 5 After the forming die presses the large-angle corrugated ring segment, it is necessary to switch the corrugated ring segment detection die 16 to measure the springback of the large-angle corrugated ring segment. At this time, the formed corrugated ring segment body 9 needs to be removed from the corrugated groove of the large-angle corrugated ring segment, and then the corrugated ring segment detection body 17 needs to be inserted into the corrugated groove. During this switching process, the large-angle corrugated ring segment will gradually spring back, causing the measured value of the corrugated ring segment detection die 16 to be less than the actual springback value of the large-angle corrugated ring segment, thus affecting the detection accuracy. Therefore, based on Example 4, as follows... Figures 1 to 7 As shown, the lower forming die 7 has negative pressure cavities 25 on both sides of the forming corrugated annular groove 8. The negative pressure cavities 25 are connected to the forming corrugated annular groove 8 through several negative pressure holes 26. These negative pressure holes 26 are spaced apart along the arc-shaped trajectory of the lower forming die 7. The lower forming die 7 is equipped with a negative pressure pump, which is connected to the negative pressure cavities 25 through a negative pressure pipe. When the forming corrugated annular body 9 presses and shapes the arc-shaped blank, the negative pressure pump operates, causing the negative pressure holes 26 to generate negative pressure that adsorbs the large-angle corrugated annular segment of the arc-shaped blank. After the corrugated ring segment 9 is formed, it is removed from the corrugated groove. The large-angle corrugated ring segment is prevented from rebounding by using negative pressure. Then, the corrugated ring segment detection body 17 is moved into the corrugated groove and the detection probe 18 contacts the inner wall of the corrugated groove. Then, the negative pressure pump stops working, so that the air pressure in the negative pressure chamber 25 is balanced with the outside. At this time, the large-angle corrugated ring segment begins to rebound, so that the detection probe 18 can accurately measure the rebound amount, which greatly improves the measurement accuracy and can accurately reflect the pressing quality of the thin-walled large-angle corrugated ring segment.

[0023] Example 6 The negative pressure hole 26 prevents the corrugated ring groove 8 from forming a complete plane, resulting in uneven pressing force on the arc-shaped blank, affecting the pressing quality. This leads to excessive springback of the large-angle corrugated ring in the area of ​​the negative pressure hole 26, causing an increased defect rate. Therefore, based on Example 5, as follows... Figures 1 to 7As shown, the negative pressure cavity 25 contains a sealing assembly, which includes an arc-shaped sealing plate 27 and a sealing rod 28. The arc-shaped sealing plate 27 has the freedom to move radially along the lower forming mold 7. Each negative pressure hole 26 corresponds to a sealing rod 28, which is fixed to the arc-shaped sealing plate 27. The sealing rod 28 can be inserted into the negative pressure hole 26, so that the end of the sealing rod 28 away from the arc-shaped sealing plate 27 is attached to the inner wall of the lower forming mold 7 to form a complete forming corrugated annular groove 8. The end of the arc-shaped sealing plate 27 away from the sealing rod 28 is equipped with a hydraulic drive mechanism, which includes a sealing hydraulic cylinder 29. The cylinder body of the sealing hydraulic cylinder 29 is installed on the outer wall of the lower forming mold 7. The telescopic rod 9 moves into the negative pressure cavity 25 and connects to the arc-shaped sealing plate 27. When the arc-shaped blank is formed and pressed, the sealing hydraulic cylinder 29 drives the arc-shaped sealing plate 27 to abut against the inner wall of the negative pressure cavity 25, so that the sealing rod 28 fits into the negative pressure hole 26, and the end of the sealing rod 28 combines with the inner wall of the corrugated groove to form a complete forming corrugation. The sealing hydraulic cylinder 29 can withstand the force of the upper forming mold 6 during the pressing process, ensuring that the position of the sealing rod 28 does not change during the pressing process, thereby improving the forming and pressing effect of the arc-shaped blank, making the springback amount of each area of ​​the large-angle corrugated ring section more consistent, thereby improving the production qualification rate of the thin-walled large-angle corrugated ring section. When the springback amount is detected, the sealing hydraulic cylinder 29 drives the arc-shaped sealing plate 27 to move away from the negative pressure hole 26, so that the product gap between the negative pressure hole 26 and the sealing rod 28 is reduced, and the negative pressure of the negative pressure cavity 25 can act on the large-angle corrugated ring section through the negative pressure hole 26.

[0024] Furthermore, since the negative pressure holes 26 are arranged along the arc direction of the lower forming mold 7, and the sealing rods 28 move radially along the lower forming mold 7 under the action of the arc-shaped sealing plate 27, in order to ensure that the sealing rods 28 can smoothly cooperate with the negative pressure holes 26, the axial direction of the negative pressure holes 26 is parallel to the moving direction of the arc-shaped sealing plate 27, and the sealing rods 28 are coaxial with the corresponding negative pressure holes 26, so that all the sealing rods 28 can smoothly cooperate with the corresponding negative pressure holes 26 under the drive of the arc-shaped sealing plate 27, realizing the cooperation and separation of the sealing rods 28 and the negative pressure holes 26, and realizing the switching between forming and inspection; the negative pressure holes 26 can also be set as conical, and the small diameter end of the negative pressure holes 26 is connected to the forming corrugated annular groove 8, and the end of the sealing rods 28 The part matches the small-diameter end of the negative pressure hole 26 and is used to cooperate with the corrugated groove to form a complete corrugated ring segment groove 8. The sealing rod 28 is cylindrical, so that there is a certain gap between the sealing rod 28 and the negative pressure hole 26. Therefore, it is not necessary to completely remove the sealing rod 28 from the negative pressure hole 26. It is only necessary to move the end of the sealing rod 28 into the interior of the negative pressure hole 26, so that a negative pressure gap is formed between the negative pressure hole 26 and the sealing rod 28. Through this negative pressure gap, the large-angle corrugated ring segment can be smoothly adsorbed by negative pressure. By moving the sealing rod 28 a short distance and setting the negative pressure hole 26 to a conical shape, it is not necessary for the axis of the negative pressure hole 26 to be parallel to the moving direction of the arc-shaped sealing plate 27, and the switching between forming and inspection can be realized.

[0025] Example 7 Because the arc-shaped sealing plate 27 has a certain range of movement within the negative pressure cavity 25, the space of the negative pressure cavity 25 is relatively large, making it difficult to generate a strong negative pressure in a short time. Therefore, based on Embodiment Six, as follows... Figures 1 to 7 As shown, an arc-shaped air cushion 30 is installed inside the negative pressure cavity 25. The arc-shaped air cushion 30 is interference-fitted between the arc-shaped sealing plate 27 and the outer wall of the negative pressure cavity 25. The arc-shaped air cushion 30 is provided with a clearance through hole 31 for the extension rod of the sealing cylinder 29 to pass through. The inflation valve of the arc-shaped air cushion 30 extends from inside the lower mold 7. Air is inflated into the arc-shaped air cushion 30 through the inflation valve, causing the arc-shaped air cushion 30 to expand, thereby sealing the space between the arc-shaped sealing plate 27 and the outer wall of the negative pressure cavity 25, greatly reducing the size of the negative pressure cavity 25. Because the arc-shaped air cushion 30 is in an interference fit state, the arc-shaped air cushion 30 can expand or compress adaptively when the arc-shaped sealing plate 27 moves. Without affecting the movement of the arc-shaped sealing plate 27, it can continuously seal the space between the arc-shaped sealing plate 27 and the outer wall of the negative pressure cavity 25. By reducing the airflow space of the negative pressure cavity 25, a strong negative pressure can be generated quickly.

[0026] Example 8 Based on Embodiment 7, the pre-pressing mold also includes a pre-pressing hydraulic cylinder 40 and a pre-pressing lifting seat 41. The pre-pressing hydraulic cylinder 40 is vertically mounted on the frame 34. The telescopic shaft of the pre-pressing hydraulic cylinder 40 is connected to the pre-pressing lifting seat 41. The upper forming mold 6 is mounted on the bottom of the pre-pressing lifting seat 41 by a screw. The telescopic movement of the pre-pressing hydraulic cylinder 40 drives the upper pre-pressing mold 2 to move in the vertical direction, completing the mold closing and mold opening of the upper pre-pressing mold 2 and the lower pre-pressing mold 3. The upper forming mold 6 is detachably mounted on the pre-pressing lifting seat 41, and the corresponding upper pre-pressing mold 2 and lower pre-pressing mold 3 can be replaced according to the size of the arc-shaped blank.

[0027] Example 9 Based on Example 8, to achieve automation, a robotic arm conveying mechanism is set up to transport the arc-shaped blank, realizing the feeding, pre-pressing, forming, and unloading of the arc-shaped blank. The robotic arm conveying mechanism includes a linear drive module and a robotic arm. Linear drive modules are arranged on both sides of the forming machine 1. An arm base is installed on the slide of the linear drive module. The robotic arm is installed on the arm base. The execution end of the robotic arm is equipped with a pneumatic gripper. The two robotic arms use pneumatic grippers to clamp the two ends of the arc-shaped blank for feeding. The arc-shaped blank is placed on the pre-pressing lower mold 3 for pre-pressing. After pressing, the two ends of the arc-shaped blank are clamped again by the pneumatic gripper. The linear drive module drives the robotic arm to move closer to the forming and pressing mold, thereby completing the automatic conveying of multiple pre-pressing and forming pressing processes, reducing labor costs and improving production efficiency.

[0028] Furthermore, such as Figures 1 to 6 As shown, when the arc-shaped blank is formed in the pre-compression corrugated ring groove 4, the large-angle corrugated ring blank will fit into the pre-compression corrugated ring groove 4. When the large-angle corrugated ring blank is formed in the forming corrugated ring groove 8, the large-angle corrugated ring will fit into the forming corrugated ring groove 8. Even if the arc-shaped blank springs back, the amount of springback makes the gap between the large-angle corrugated ring and the bottom wall of the pre-compression corrugated ring groove 4 small. Similarly, the small gap between the large-angle corrugated ring and the forming corrugated ring groove 8 cannot meet the clamping function of the pneumatic gripper. To provide sufficient space for movement, both the pre-compression lower mold 3 and the forming lower mold 7 are equipped with lifting mechanisms. These lifting mechanisms include a lifting shaft 32, a shaft push plate 33, and a push plate hydraulic cylinder 42. The pre-compression lower mold 3 has multiple lifting grooves 43 on the inner bottom wall of the pre-compression corrugated annular groove 4, and the forming lower mold 7 has multiple lifting grooves 43 on the inner bottom wall of the forming corrugated annular groove 8. Each lifting groove 43 is fitted with a lifting shaft 32. Both the pre-compression lower mold 3 and the forming lower mold 7 have a push plate mounting cavity 44 on one side of the lifting groove 43. The push plate mounting cavity 44 communicates with the lifting groove 43. A shaft push plate 33 is provided inside the cavity 44. A lifting inclined surface 45 is provided on the top of the shaft push plate 33. A lifting ball 46 is fixed at the bottom of the lifting shaft 32. The lifting ball 46 contacts the lifting inclined surface 45. Push plate hydraulic cylinders 42 are installed on the outer walls of both the pre-pressing lower mold 3 and the forming lower mold 7. The telescopic shaft of the push plate hydraulic cylinder 42 is connected to the shaft push plate 33. When the arc-shaped blank is pressed and formed, the top surface of the lifting shaft 32 in the pre-pressing lower mold 3 is part of the pre-pressing corrugated annular groove 4. The top surface of the lifting shaft 32 in the forming lower mold 7 is... The surface is part of the corrugated annular groove 8. When it is necessary to transport the arc-shaped blank, the push plate hydraulic cylinder 42 drives the shaft push plate 33 to move close to the lifting shaft 32, so that the lifting inclined surface 45 lifts the lifting ball 46, thereby driving the lifting shaft 32 to move upward and lift the arc-shaped blank, so that a large space is formed between the arc-shaped blank and the bottom wall of the mold cavity, so that the pneumatic gripper can clamp the end of the arc-shaped blank through this space, thereby realizing the automatic clamping and conveying of the arc-shaped blank, which has the advantages of high automation, high production efficiency and low labor cost.

[0029] Example 10 Based on Example 9, a method for forming a graded pressing thin-walled large-angle corrugated ring segment, using the aforementioned graded pressing thin-walled large-angle corrugated ring segment forming apparatus, includes the following steps: S1. Load the arc-shaped blank onto the forming machine 1; S2. The arc-shaped ring section blank is first processed on the arc-shaped blank by multiple pre-pressing dies. The order of use of multiple pre-pressing dies satisfies the requirement to gradually bring the large-angle corrugated ring section blank closer to the standard large-angle corrugated ring section forming. S3. Then, use a forming and pressing mold to process the arc-shaped ring blank, so that standard large-angle corrugated segments are formed on the arc-shaped ring blank. S4. Use multiple detection components to detect the large-angle corrugated section of the arc-shaped ring blank to obtain the springback amount of the large-angle corrugated section; when the springback amount is within the error range, the processing is completed and the arc-shaped ring blank is cut; when the springback amount exceeds the error range, proceed to the next step. S5. Increase the pressing pressure and molding temperature, and process the arc-shaped ring blank again through the molding pressing mold; S6. The springback amount of the large-angle corrugated section is detected by the detection component. When the springback amount is within the error range, the processing is completed and the arc-shaped ring section blank is cut. When the springback amount exceeds the error range, the operation of S5 above is repeated.

Claims

1. A forming apparatus for graded pressing of thin-walled, large-angle corrugated ring segments, characterized in that, The system includes a forming machine and a pre-pressing assembly and a forming pressing mold mounted on the forming machine. The pre-pressing assembly includes multiple pre-pressing molds arranged sequentially near the forming pressing mold. Each pre-pressing mold includes an upper pre-pressing mold and a lower pre-pressing mold. The top of the lower pre-pressing mold has a pre-pressing corrugated ring groove. The upper pre-pressing mold is positioned directly above the lower pre-pressing mold, and a pre-pressing corrugated ring body is fixed to the bottom of the upper pre-pressing mold. The upper pre-pressing mold, through the cooperation of the pre-pressing corrugated ring body and the pre-pressing corrugated ring groove, forms a large-angle corrugated ring blank on an arc-shaped ring blank. The forming pressing mold includes an upper forming mold, a lower forming mold, and a corrugated ring detection mold. The top of the lower forming mold has a forming corrugated ring groove. The upper forming mold is positioned directly above the lower forming mold, and a forming corrugated ring body is fixed to the bottom of the upper forming mold. The corrugated ring segment body and the formed corrugated ring segment groove are matched to press the large-angle corrugated ring segment blank into a standard large-angle corrugated ring segment. The large-angle corrugated ring segment blanks formed by multiple pre-pressing molds gradually approach the standard large-angle corrugated ring segment. A corrugated ring segment detection body is formed on the corrugated ring segment detection mold. Multiple detection components are arranged on the inner and outer sides of the corrugated ring segment detection body along its own trajectory direction. The detection components on both sides of the corrugated ring segment detection body are staggered along its own trajectory direction. The detection component includes a detection probe and a detection spring. A detection cavity is provided in the corrugated ring segment detection mold. Multiple detection holes communicating with the detection cavity are opened on both sides of the corrugated ring segment detection body. Each detection probe corresponds to a detection hole. The detection probe is set in the detection cavity, and one end of the detection probe protrudes from the detection hole.

2. The forming apparatus for graded pressing of thin-walled, large-angle corrugated ring segments according to claim 1, characterized in that, The lower forming mold has lower heating holes on both its inner and outer sides, and a first heating rod is fixed inside the lower heating hole. The upper forming mold has upper heating holes on both its inner and outer sides, and a second heating rod is fixed inside the upper heating hole. Both the second heating rod and the first heating rod are wound with resistance heating wires.

3. The forming apparatus for graded pressing of thin-walled, large-angle corrugated ring segments according to claim 1, characterized in that, The forming and pressing mold also includes a rotary switching body, which is rotatably installed and its rotation axis is horizontally set. The upper forming mold is installed at the bottom of the rotary switching body, and the corrugated ring segment detection mold is installed on one side of the rotary switching body. The rotary switching body deflects the corrugated ring segment body or the corrugated ring segment detection body to correspond to the corrugated ring segment groove. A spring plate is fixed at the other end of the detection probe, and the detection spring is sleeved on the detection probe. The two ends of the detection spring are respectively connected to the spring plate and the corrugated ring segment detection body.

4. The forming apparatus for graded pressing of thin-walled, large-angle corrugated ring segments according to claim 3, characterized in that, The detection assembly also includes a laser rangefinder sensor. A reflector is fixed to the side wall of the spring disc. The laser rangefinder sensor is installed in the detection cavity and is located above the corrugated ring detection body. The reflector is located on the detection path of the laser rangefinder sensor.

5. The forming apparatus for graded pressing of thin-walled, large-angle corrugated ring segments according to claim 4, characterized in that, Negative pressure cavities are provided on both sides of the forming corrugated annular groove in the lower forming mold. The negative pressure cavities are connected to the forming corrugated annular groove through a number of negative pressure holes. The number of negative pressure holes are spaced apart along the arc trajectory of the lower forming mold. The lower forming mold is equipped with a negative pressure pump, which is connected to the negative pressure cavities through a negative pressure pipe.

6. The forming apparatus for graded pressing of thin-walled, large-angle corrugated ring segments according to claim 5, characterized in that, The negative pressure cavity sealing assembly includes an arc-shaped sealing plate and a sealing rod. The arc-shaped sealing plate has the freedom to move radially along the lower forming mold. Each negative pressure hole corresponds to a sealing rod. The sealing rod is fixed on the arc-shaped sealing plate and can be inserted into the negative pressure hole, so that the end of the sealing rod away from the arc-shaped sealing plate is attached to the inner wall of the lower forming mold to form a complete forming corrugated annular groove.

7. The forming apparatus for graded pressing of thin-walled, large-angle corrugated ring segments according to claim 6, characterized in that, The arc-shaped sealing plate is equipped with a hydraulic drive mechanism at one end away from the sealing rod. The hydraulic drive mechanism includes a sealing hydraulic cylinder. The cylinder body of the sealing hydraulic cylinder is installed on the outer wall of the forming lower mold. The telescopic rod of the sealing hydraulic cylinder moves into the negative pressure cavity and connects to the arc-shaped sealing plate.

8. The forming apparatus for graded pressing of thin-walled, large-angle corrugated ring segments according to claim 3, characterized in that, A frame is fixed on the molding machine platform. The molding and pressing mold also includes a molding hydraulic cylinder and a lifting bearing seat. The molding hydraulic cylinder is vertically mounted on the frame. The telescopic shaft of the molding hydraulic cylinder is connected to the lifting bearing seat. A U-shaped opening is provided at the bottom of the lifting bearing seat. A switching shaft is provided in the U-shaped opening. The switching shaft is rotatably connected to the lifting bearing seat. A switching shaft seat is fixed at the top of the rotating switching body. The switching shaft seat is fixedly sleeved on the switching shaft. A motor is installed on the side wall of the lifting bearing seat. The output shaft of the motor is connected to the switching shaft through a coupling.

9. The forming apparatus for graded pressing of thin-walled, large-angle corrugated ring segments according to claim 8, characterized in that, The pre-pressing mold also includes a pre-pressing hydraulic cylinder and a pre-pressing lifting seat. The pre-pressing hydraulic cylinder is vertically mounted on the frame, and the telescopic shaft of the pre-pressing hydraulic cylinder is connected to the pre-pressing lifting seat. The upper forming mold is mounted on the bottom of the pre-pressing lifting seat via a screw.

10. A method for forming thin-walled, large-angle corrugated ring segments by graded pressing, wherein the forming apparatus for graded pressing of thin-walled, large-angle corrugated ring segments as described in claim 4 is used for production, characterized in that... Includes the following steps: S1. Load the arc-shaped blank onto the forming machine table; S2. The arc-shaped ring section blank is first processed on the arc-shaped blank by multiple pre-pressing dies. The order of use of multiple pre-pressing dies satisfies the requirement to gradually bring the large-angle corrugated ring section blank closer to the standard large-angle corrugated ring section forming. S3. Then, use a forming and pressing mold to process the arc-shaped ring blank, so that standard large-angle corrugated segments are formed on the arc-shaped ring blank. S4. Use multiple detection components to detect the large-angle corrugated section of the arc-shaped ring blank to obtain the springback amount of the large-angle corrugated section; when the springback amount is within the error range, the processing is completed and the arc-shaped ring blank is cut; when the springback amount exceeds the error range, proceed to the next step. S5. Increase the pressing pressure and molding temperature, and process the arc-shaped ring blank again through the molding pressing mold; S6. The springback amount of the large-angle corrugated section is detected by the detection component. When the springback amount is within the error range, the processing is completed and the arc-shaped ring section blank is cut. When the springback amount exceeds the error range, the operation of S5 above is repeated.

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